Patent Publication Number: US-2018033655-A1

Title: Apparatus and method for treating substrate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     A claim for priority under 35 U.S.C. §119 is made to Korean Patent Application No. 10-2016-0096892 filed Jul. 29, 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 and a method for treating a substrate. 
     In order to manufacture a semiconductor device, a desired pattern is formed on a substrate through various processes such as, photographing, etching, ashing, ion injection, and deposition of thin films. Various treatment liquids are used in the processes, and contaminants and particles are generated during the process. In order to solve this, a cleaning process for cleaning contaminants and particles is essentially performed before and after the process. 
     In general, in the cleaning process, a substrate is dried after being treated with a chemical and a rinsing liquid. The drying operation is a process of drying the rinsing liquid residing on the substrate, and dries the substrate with an organic solvent such as isopropyl alcohol (IPA). However, as a critical dimension (CD) between the patterns formed in the substrate becomes smaller, the organic solvent resides in spaces between the patterns. 
     Recently, a supercritical treatment process has been performed to remove an organic solvent residing on a substrate. The supercritical treatment process is performed in a space closed from the outside to satisfy a specific condition of a supercritical fluid. 
     Although the volume of a space, in which a supercritical process is generally performed, has been reduced or a method of reducing the amount of supplied isopropyl alcohol has been used to shorten a process time during the supercritical treatment process, there is a limit in a method of reducing the space or the amount of supplied isopropyl alcohol when optimization of the process is considered. 
     SUMMARY 
     Embodiments of the inventive concept provide an apparatus and a method for shortening a supercritical treatment process time. 
     The objects of the inventive concept are not limited to the above-described ones. Other technical objects that are not mentioned will be clearly understood from the following description by those skilled in the art to which the inventive concept pertains. 
     In accordance with an aspect of the inventive concept, there is provided method for treating a substrate, the method including supplying a mixture liquid obtained by mixing an additive with an organic solvent onto a substrate, and after the supplying of the mixture liquid, removing the mixture liquid from the substrate by supplying a supercritical fluid to the substrate and dissolving the mixture liquid in the supercritical fluid, wherein the additive has a surface tension that is lower than that of the organic solvent and a boiling point that is lower than that of the organic solvent. 
     A solubility of the additive for the organic solvent may be higher than that of hexane. 
     The organic solvent may be isopropyl alcohol (IPA). 
     The supercritical fluid may be carbon dioxide (CO 2 ). 
     The additive may include a fluid pertaining to one group consisting of fluorinated alcohol, alcohol, fluorinated ether, ether, fluorinated ketone, and ketone. 
     In accordance with another aspect of the inventive concept, there is provided a method for treating a substrate, the method including supplying a mixture liquid obtained by mixing an additive with an organic solvent onto a substrate, and after the supplying of the mixture liquid, removing the mixture liquid from the substrate by supplying a supercritical fluid to the substrate and dissolving the mixture liquid in the supercritical fluid, wherein a solubility of the additive for the supercritical fluid is higher than that of the organic solvent. 
     A diffusion speed of the additive for the supercritical fluid may be higher than that of organic solvent. 
     In accordance with another aspect of the inventive concept, there is provided an apparatus for treating a substrate, the apparatus including a liquid treating chamber configured to liquid-treat the substrate, a drying chamber configured to dry the substrate, and a transfer unit configured to transfer the substrate between the liquid treating chamber and the drying chamber, wherein the liquid treating chamber liquid-treats the substrate with a mixture liquid obtained by mixing an additive with an organic solvent, wherein the drying chamber removes the mixture liquid from the substrate by supplying the supercritical fluid to the substrate and dissolving the mixture liquid in the supercritical fluid, and wherein the additive has a surface tension that is lower than that of the organic solvent and a boiling point that is lower than that of the organic solvent. 
     A solubility of the additive for the organic solvent may be higher than that of hexane. 
     In accordance with another aspect of the inventive concept, there is provided an apparatus for treating a substrate, the apparatus including a liquid treating chamber configured to liquid-treat the substrate, a drying chamber configured to dry the substrate, and a transfer unit configured to transfer the substrate between the liquid treating chamber and the drying chamber, wherein the liquid treating chamber liquid-treats the substrate with a mixture liquid obtained by mixing an additive with an organic solvent, wherein the drying chamber removes the mixture liquid from the substrate by supplying the supercritical fluid to the substrate and dissolving the mixture liquid in the supercritical fluid, and wherein a solubility of the additive for the supercritical fluid is higher than that of the organic solvent. 
     A diffusion speed of the additive for the supercritical fluid is higher than that of organic solvent. 
    
    
     
       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 plan view illustrating a substrate treating system according to an embodiment of the inventive concept; 
         FIG. 2  is a sectional view illustrating an apparatus for cleaning a substrate in a first process chamber of  FIG. 1 ; 
         FIG. 3  is a sectional view illustrating an apparatus for drying a substrate in a second process chamber of  FIG. 1 ; 
         FIG. 4  is a perspective view illustrating a substrate support unit of  FIG. 3 ; 
         FIG. 5  is a flowchart illustrating a method for treating a substrate according to an embodiment of the inventive concept. 
     
    
    
     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. 
     An embodiment of the inventive concept will be described with reference to  FIGS. 1 to 5 . 
       FIG. 1  is a plan view illustrating a substrate treating system according to an embodiment of the inventive concept. Referring to  FIG. 1 , the substrate treating system  1  is provided as an apparatus for treating a substrate. The substrate treating system  1  has an index module  10  and a process executing module  20 , and the index module  10  has a plurality of load ports  120  and a feeding frame  140 . The load ports  120 , the feeding frame  140 , and the process executing module  20  may be sequentially arranged in a row. Hereinafter, a direction in which the load ports  120 , the feeding frame  140 , and the process executing module  20  are arranged will be referred to as a first direction  12 , 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 normal to a plane containing the first direction  12  and the second direction  14  will be referred to as a third direction  16 . 
     A carrier  18 , in which a substrate W is received, is seated on the load port  120 . A plurality of load ports  120  are provided, and are disposed along the second direction  14  in a row.  FIG. 2  illustrates that four load ports  120  are provided. The number of the load ports  120  may be increased or decreased according to the process efficiency of the process executing module  20 , a footprint condition, and the like. A plurality of slots (not illustrated) provided to support peripheries of substrates are formed in the carrier  18 . A plurality of slots are provided along the third direction  16 , and the substrate is situated in the carrier such that the substrates are stacked to be spaced apart from each other along the third direction  16 . A front opening unified pod (FOUP) may be used as the carrier  18 . 
     The process executing module  20  includes a buffer unit  220 , a transfer chamber  240 , first process chambers  260 , and second process chambers  280 . The transfer chamber  240  is disposed such that the lengthwise direction thereof is in parallel to the first direction  12 . The first process chambers  260  are disposed on one side of the transfer chamber  240  along the second direction  14 , and the second process chambers  280  are disposed on an opposite side of the transfer chamber  240 . The first process chambers  260  and the second process chambers  280  may be provided to be symmetrical to each other with respect to the transfer chamber  240 . Some of the first process chambers  260  are disposed along the lengthwise direction of the transfer chamber  240 . Furthermore, some of the first process chambers  260  are disposed to be stacked on each other. That is, the first process chambers  260  having an array of A by B (A and B are natural numbers) may be disposed on one side of the transfer chamber  240 . Here, A is the number of the first process chambers  260  provided in a row along the first direction  12 , and B is the number of the first process chambers  260  provided in a row along the third direction  16 . When four or six first process chambers  260  are provided on one side of the transfer chamber  240 , the first process chambers  260  may be arranged in an array of 2 by 2 or 3 by 2. The number of the first process chambers  260  may increase or decrease. Similarly to the first process chambers  260 , the second process chambers  280  may be disposed in an array of M by N (M and N are natural numbers). Here, M and N may be same numbers as A and B. Unlike the above description, the first process chambers  260  and the second process chambers  280  may be provided only on one side of the transfer chamber  240 . Further, unlike the above description, the first process chambers  260  and the second process chambers  280  may be provided on opposite sides of the transfer chamber  240  in a single layer. Selectively, the first process chambers  260  may be stacked on one side of the transfer chamber  240 , and the second process chambers  280  may be stacked on an opposite side of the transfer chamber  240 . Further, unlike the above description, the first process chambers  260  and the second process chambers  280  may be provided in various arrangements. 
     A buffer unit  220  is disposed between the feeding frame  140  and the transfer chamber  240 . The buffer unit  220  provides a space in which the substrates W stay before being transported, between the transfer chamber  240  and the feeding frame  140 . Slots (not illustrated) in which the substrates W are positioned are provided in the buffer unit  220 , and a plurality of slots (not illustrated) are provided to be spaced apart from each other along the third direction  16 . Faces of the buffer unit  220  that faces the feeding frame  140  and faces the transfer chamber  240  are opened. 
     The feeding frame  140  transports the substrates W between the carriers  18  seated on the load port  120  and the buffer unit  220 . An index rail  142  and an index robot  144  are provided in the feeding frame  140 . The index rail  142  is provided such that the lengthwise direction thereof is in parallel to the second direction  14 . The index robot  144  is installed on the index rail  142 , and is linearly moved in the second direction  14  along the index rail  142 . The index robot  144  has a base  144   a , a body  144   b , and a plurality of index arms  144   c . The base  144   a  is installed to be moved along the index rail  142 . The body  144   b  is coupled to the base  144   a . The body  144   b  is provided to be moved along the third direction  16  on the base  144   a . The body  144   b  is provided to be rotated on the base  144   a . The index arms  144   c  are coupled to the body  144   b , and are provided to be moved forwards and rearwards with respect to the body  144   b . A plurality of index arms  144   c  are provided to be driven individually. The index arms  144   c  are disposed to be stacked so as to be spaced apart from each other along the third direction  16 . Some of the index arms  144   c  are used when the substrates W are transported to the carrier  18  from the process executing module  20 , and the others of the index arms  144   c  may be used when the substrates W are transported from the carrier  18  to the process executing module  20 . This structure may prevent particles generated from the substrates W before the process treatment from being attached to the substrates W after the process treatment in the process of carrying the substrates W in and out by the index robot  144 . 
     A transfer area in which the substrate W is transferred between two of the buffer unit  220 , a first process chamber  260 , and the second process chambers  280  is provided in the interior of the transfer chamber  240 . An guide rail  242  and a transfer unit  244  are provided in the transfer chamber  240 . The guide rail  242  is arranged such that the lengthwise direction thereof is in parallel to the first direction  12 . The transfer unit  244  transfers the substrate W between any two of the buffer unit  220 , the first process chambers  260 , and the second process chambers  280 . The transfer unit  244  is installed on the guide rail  242 , and is linearly moved along the first direction  12  on the index rail  242 . 
     The first process chambers  260  and the second process chambers  280  may sequentially perform a process on one substrate W. For example, the first process chambers  260  may be liquid treating chambers in which a liquid treating process, such as a chemical process and a rinsing process, of supplying a treatment liquid and treating the substrate W and a primary drying process are performed, and the second process chambers  280  may be drying chambers in which a secondary drying process is performed on the substrate W. According to an embodiment, the primary drying process may be a process of liquid-treating the substrate by supplying a mixture liquid obtained by mixing an additive with an organic solvent as a treatment liquid, and the secondary drying process may be a process of removing the mixture liquid on the substrate W from the substrate W by supplying a supercritical fluid to the substrate W and dissolving the mixture liquid in the supercritical fluid. An isopropyl alcohol (IPA) liquid may be used as an organic solvent, and carbon dioxide (CO 2 ) may be used as a supercritical fluid. The transfer unit  244  transfers the substrate W from the first process chamber  260  to the second process chamber  280  while the mixture liquid supplied from the first process chamber  260  resides on the substrate W. 
     Hereinafter, a substrate treating apparatus  300  provided in the first process chamber  260  will be described.  FIG. 2  is a sectional view illustrating an apparatus for cleaning a substrate in the first process chamber  260  of  FIG. 1 . Referring to  FIG. 2 , the substrate treating apparatus  300  may be provided as an apparatus for cleaning the substrate in the first process chamber  260  of  FIG. 1 . The substrate treating apparatus  300  includes a treatment container  320 , a spin head  340 , an elevation unit  360 , and a liquid supply unit  380 . 
     The treatment container  320  provides a space in which a substrate treating process is performed, and an upper side of the treatment container  320  is opened. The treatment container  320  has an inner recovery vessel  322 , an intermediate recovery vessel  324 , and an outer recovery vessel  326 . The recovery vessels  322 ,  324 , and  326  recover different treatment liquids used in the process. The inner recovery vessel  322  has an annular ring shape that surrounds the spin head  340 , the intermediate recovery vessel  324  has an annular ring shape that surrounds the inner recovery vessel  322 , and the outer recovery vessel  326  has an annular ring shape that surrounds the intermediate recovery vessel  324 . An inner space  322   a  of the inner recovery vessel  322 , a space  324   a  between the inner recovery vessel  322  and the intermediate recovery vessel  324 , and a space  326   a  between the intermediate recovery vessel  324  and the outer recovery vessel  326  function as inlets through which the treatment liquids are introduced into the inner recovery vessel  322 , the intermediate recovery vessel  324 , and the outer recovery vessel  326 . Recovery lines  322   b ,  324   b , and  326   b  extending from the recovery vessels  322 ,  324 , and  326  perpendicularly in the downward direction of the bottom surfaces thereof are connected to the recovery vessels  322 ,  324 , and  326 , respectively. The recovery lines  322   b ,  324   b , and  326   b  discharge the treatment liquid introduced through the recovery vessels  322 ,  324 , and  326 . The discharged treatment liquids may be reused through an external treatment liquid recycling system (not illustrated). 
     The spin head  340  is disposed in the treatment container  320  and is provided as a substrate support unit  340  that supports the substrate W in the treatment container  320 . The spin head  340  supports and rotates the substrate W during the process. The spin head  340  has a body  342 , a plurality of support pins  334 , a plurality of chuck pins  346 , and a support shaft  348 . The body  342  has an upper surface having a substantially circular shape when viewed from the top. The support shaft  348  that may be rotated by a motor  349  is fixedly coupled to the bottom of the body  342 . A plurality of support pins  334  are provided. The support pins  334  may be arranged to be spaced apart from each other at a periphery of the upper surface of the body  342  and protrude upwards from the body  342 . The support pins  334  are arranged to have a generally annular ring shape through combination thereof. The support pins  334  support a periphery of a rear surface of the substrate such that the substrate W is spaced apart from the upper surface of the body  342  by a predetermined distance. A plurality of chuck pins  346  are provided. The chuck pins  346  are arranged to be more distant from the center of the body  342  than the support pins  334 . The chuck pins  346  are provided to protrude upwards from the body  342 . The chuck pins  346  support a side of the substrate W such that the substrate W is not separated laterally from a proper place when the spin head  340  is rotated. The chuck pins  346  are provided to be linearly moved between a standby position and a support position along a radial direction of the body  342 . The standby position is a position that is more distant from the center of the body  342  than the support position. When the substrate W is loaded on or unloaded from the spin head  340 , the chuck pins  346  are located at the standby position, and when a process is performed on the substrate W, the chuck pins  346  are located at the support position. The chuck pins  346  are in contact with the side of the substrate W at the support position. The transfer unit  244  loads and unloads the substrate W to and from the spin head  340 . 
     The elevation unit  360  linearly moves the treatment container  320  upwards and downwards. When the treatment container  320  is moved upwards and downwards, a relative height of the treatment container  320  to the spin head  340  is changed. The elevation unit  360  has a bracket  362 , a movable shaft  364 , and a driver  366 . The bracket  362  is fixedly installed on an outer wall of the treatment container  320 , and the movable shaft  364  that is moved upwards and downwards by the driver  366  is fixedly coupled to the bracket  362 . The treatment container  320  is lowered such that, when the substrate W is positioned on the spin head  340  or is lifted from the spin head  340 , the spin head  340  protrudes to the upper side of the treatment container  320 . When the process is performed, the height of the treatment container  320  is adjusted such that the treatment liquid is introduced into the preset recovery vessel  360  according to the kind of the treatment liquid supplied to the substrate W. For example, the substrate W is located at a height corresponding to an interior space  322   a  of the inner recovery vessel  322  while the substrate W is treated by a first treatment fluid. Further, the substrate W may be located at a height corresponding to a space  324   a  between the inner recovery vessel  322  and the intermediate recovery vessel  324  and a space  326   a  between the intermediate recovery vessel  324  and the outer recovery vessel  326  while the substrate W is treated by a second treatment liquid and a third treatment liquid respectively. Unlike those described above, the elevation unit  360  may move the spin head  340 , instead of the treatment container  320 , upwards and downwards. 
     The liquid supply unit  380  supplies a treatment liquid onto the substrate W on the spin head  340 . The liquid supply unit  380  has a nozzle support  382 , a nozzle  384 , a support shaft  386 , a driver  388 , and a liquid supply member  281 . The lengthwise direction of the support shaft  386  is provided along the third direction  16 , and the driver  388  is coupled to a lower end of the support shaft  386 . The driver  388  rotates and elevates the support shaft  386 . The nozzle support  382  is vertically coupled to an end opposite to an end of the support shaft  386  coupled to the driver  388 . The nozzle  384  is installed on the bottom surface of an end of the nozzle support  382 . The nozzle  384  is moved to a process location and a standby location by the driver  388 . The process location is a location at which the nozzle  384  is arranged at a vertical upper portion of the treatment container  320 , and the standby location is a location that deviates from the vertical upper portion of the treatment container  320 . One or a plurality of liquid supply units  380  may be provided. When a plurality of liquid supply units  380  are provided, a chemical, a rinsing liquid, and a mixture liquid as treatment liquid may be provided through different liquid supply units  380 , respectively. The chemical may be a liquid having a strong acid or alkali property. The rinsing liquid may be pure water. The additive mixed with the organic solvent is provided as a fluid having a solubility for the supercritical fluid supplied from the second process chamber  260  and a diffusion speed in a state in which the additive is dissolved in the supercritical fluid, which are higher than those of the organic solvent. Accordingly, as compared when only the organic solvent is supplied to the substrate through an operation of the additive, the mixture liquid is dried by the supercritical fluid more rapidly. A fluid having a surface tension and a boiling point that are lower than those of the organic solvent has a solubility for the supercritical fluid and a diffusion speed in a state in which the fluid is dissolved in the supercritical fluid, which are higher than those of the organic solvent. Further, because the additive is mixed with the organic solvent to form a mixture, it is provided as a fluid that is easily dissolved in the organic solvent. According to an embodiment, the additive is provided as a fluid having a solubility for the organic solvent, which is higher than that of hexane. For example, the additive may be a fluid pertaining to one group consisting of fluorinated alcohol, alcohol, fluorinated ether, ether, fluorinated ketone, and ketone. Unlike this, the additive may be various kinds of fluids that have a solubility for the supercritical fluid and a diffusion speed in a state in which the additive is dissolved in the supercritical fluid, which are higher than those of the organic solvent and have a solubility for the organic solvent, which is higher than that of hexane. The liquid supply unit  380  supplies a mixture liquid onto the substrate W on the spin head  340 . 
     According to an embodiment, the mixture liquid is supplied to the nozzle  384  by a liquid supply member  381 . For example, the liquid supply member  381  includes an organic solvent storage unit  381   a , an additive storage unit  381   b , a mixing unit  381   c , and a controller  381   d.    
     An organic solvent is stored in the organic solvent storage unit  381   a . An additive is stored in the additive storage unit  381   b . The organic solvent supplied from the organic solvent storage unit  381   a  and the additive supplied from the additive storage unit  381   b  are mixed in the mixing unit  381   c . Valves are provided in connecting lines connecting the nozzle  384 , the mixing unit  381   c , the organic solvent storage unit  381   a , and the additive storage unit  381   b , respectively. The controller  381   d  controls the valves to adjust whether the mixture liquid is to be supplied and the ratios of the organic solvent and the additive, which have been mixed with the mixture liquid. The ratios of the organic solvent and the additive may be determined to specific ratios from simulations or data by tests. 
     A substrate treating apparatus  400  that performs a second drying process of the substrate is provided in the second process chamber  280 . The substrate treating apparatus  400  secondarily dries the substrate W primarily dried in the first process chamber. The substrate treating apparatus  400  may dry the substrate W by using a supercritical solvent.  FIG. 3  is a sectional view illustrating an apparatus for drying a substrate in the second process chamber  280  of  FIG. 1 . Referring to  FIG. 3 , the substrate treating apparatus  400  may be provided as an apparatus for drying the substrate in the second process chamber  280  of  FIG. 1 . The substrate treating apparatus  400  includes a housing  410 , a substrate support unit  440 , an elevation member  450 , a heating member  460 , a fluid supply unit  470 , an interruption member  480 , and a sealing unit  490 . 
     The housing  410  has a treatment space  412  in which the substrate W is treated, in the interior thereof. The housing  410  closes the treatment space  412  from the outside while the substrate W is treated. The housing  410  includes a lower housing  420  and an upper housing  430 . The lower housing  420  has an open-topped cup shape. An exhaust port  426  is formed on a bottom surface of the inside of the lower housing  420 . When viewed from the top, the exhaust port  426  may deviate from a central axis of the lower housing  420 . A pressure reducing member is connected to the exhaust port  426  such that particles generated in the treatment space  412  may be exhausted. Further, the internal pressure of the treatment space  412  may be adjusted through the exhaust port  426 . 
     The upper housing  430  is combined with the lower housing  420  to define a treatment space  412  therebetween. The upper housing  430  is located above the lower housing  420 . The upper housing  430  has a circular plate shape. For example, the upper housing  430  may have a diameter dimensioned such that the bottom surface of the upper housing  430  faces an upper end of the lower housing  420  at a location at which the central axis of the upper housing  430  coincides with the central axis of the lower housing  420 . 
     The substrate supporting unit  440  supports the substrate W in the treatment space  412 .  FIG. 4  is a perspective view illustrating a substrate support unit  440  of  FIG. 3 . Referring to  FIG. 4 , the substrate support unit  440  supports the substrate W such that a treatment surface of the substrate W faces the upper side. The substrate support unit  440  includes a support member  442  and a substrate maintaining member  444 . The support member  442  has a bar shape that extends downwards from a bottom surface of the upper housing  430 . A plurality of support members  442  are provided. For example, four support members  442  may be provided. The substrate maintaining member  444  supports a peripheral area of a bottom surface of the substrate W. A plurality of substrate maintaining members  444  are provided, and support different areas of the substrate W. For example, two substrate maintaining members  444  may be provided. When viewed from the top, the substrate maintaining member  444  has a rounded plate shape. When viewed from the top, the substrate maintaining member  444  is located inside the support member. The substrate maintaining members  444  are combined with each other to have a ring shape. The substrate maintaining members  444  are spaced apart from each other. 
     Referring to  FIG. 3  again, the elevation member  450  adjusts a relative location between the upper housing  430  and the lower housing  420 . The elevation member  450  moves one of the upper housing  430  and the lower housing  420 . It is described in the embodiment that a location of the upper housing  430  is fixed and a distance between the upper housing  430  and the lower housing  420  is adjusted by moving the lower housing  420 . Optionally, the substrate support unit  440  installed in the fixed lower housing  420 , and the upper housing  430  may be moved. The elevation member  450  moves the lower housing  420  such that the relative location between the upper housing  430  and the lower housing  420  is moved to an opening location and a closing location. Here, the opening location is defined as a location at which the upper housing  430  and the lower housing  420  are spaced from each other such that the treatment space  412  communicates with the outside, and the closing location is defined as a location at which the upper housing  430  and the lower housing  420  contact each other such that the treatment space  412  is closed from the outside by the upper housing  430  and the lower housing  420 . The body elevation member  450  elevates the lower housing  420  to open or close the treatment space  412 . The elevation member  450  includes a plurality of elevation shafts  452  that connects the upper housing  430  and the lower housing  420 . The elevation shafts  452  are located between an upper end of the lower housing  420  and the upper housing  430 . The elevation shafts  452  are arranged along a circumferential direction of an upper end of the lower housing  420 . The elevation shafts  452  may pass through the upper housing  430  to be fixedly coupled to an upper end of the lower housing  420 . As the elevation shafts  452  is lifted or lowered, the height of the lower housing  420  is changed and a distance between the upper housing  430  and the lower housing  420  may be adjusted. 
     The heating member  460  heats the treatment space  412 . The heating member  460  heats the supercritical fluid supplied to the treatment space  412  to a critical temperature or higher to maintain a phase of the supercritical fluid. The heating member  460  may be buried and installed in at least one wall of the upper housing  430  and the lower housing  420 . For example, the heating member  460  may be a heater that receives electric power from the outside to generate heat. 
     The fluid supply unit  470  supplies a supercritical fluid to the treatment space  412 . The fluid supply unit  470  includes an upper supply port  472  and a lower supply port  474 . The upper supply port  472  is formed in the upper housing  430 , and the lower supply port  474  is formed in the lower housing  420 . The upper supply port  472  and the lower supply port  474  may be located to be opposite to each other vertically. The upper supply port  472  and the lower supply port  474  may be located to aligned with the central axis of the treatment space  412 . The same kind of supercritical fluid is supplied to the upper supply port  472  and the lower supply port  474 . According to an embodiment, a supercritical fluid may be supplied from a supply port facing a non-treatment surface of the substrate W, and then the supercritical fluid may be supplied from a supply port facing a treatment surface of the substrate W. Accordingly, the supercritical fluid may be supplied from the lower supply port  474 , and then the supercritical fluid may be supplied from the upper supply port  472 . This is because the initially supplied fluid may be prevented from being supplied to the substrate W while not reaching a threshold pressure or a threshold temperature. 
     The blocking member  480  prevents the fluid supplied from the lower supply port  474  from being directly supplied to a non-treatment surface of the substrate W. The blocking member  480  may include a blocking plate  482  and a support  484 . The blocking plate  482  is located between the lower supply port  474  and the substrate support unit  440 . The blocking plate  482  has a disk shape. The blocking plate  482  has a diameter that is smaller than an inner diameter of the lower housing  420 . When viewed from the top, the blocking plate  482  has a diameter by which both of the lower supply port  474  and the exhaustion port  426  are covered. For example, the blocking plate  482  may correspond to the diameter of the substrate W or have a larger diameter. The support  484  supports the blocking plate  482 . A plurality of supports  484  are provided to be arranged along a circumferential direction of the blocking plate  482 . The supports  484  are arranged to be spaced apart from each other by a specific interval. 
     The sealing unit  490  closed an aperture between the upper housing  430  and the lower housing  420  located at a closing location such that the treatment space  412  is closed from the outside. 
     Next, a method for treating a substrate by using the substrate treating system  1  of  FIG. 1  according to an embodiment of the inventive concept will be described.  FIG. 5  is a flowchart illustrating a method for treating a substrate according to an embodiment of the inventive concept. Referring to  FIGS. 1 and 5 , the substrate treating method includes a mixture liquid supplying operation S 10 , a transfer operation S 20 , and a mixture liquid drying operation S 30 . The mixture liquid supplying operation S 10 , the transfer operation S 20 , and the mixture liquid drying operation S 30  are sequentially performed. 
     In the mixture liquid supplying operation S 10 , the substrate W is liquid-treated in the liquid treating chamber  260 . In the mixture liquid supplying operation S 10 , the mixture liquid obtained by mixing an additive with an organic solvent is supplied onto the substrate W to liquid-treat the substrate W in the liquid treating chamber  260 . 
     The transfer operation S 20  is performed between the liquid treating operation S 10  and the drying operation S 30 . In the transfer operation S 20 , the transfer unit  244  transfers the substrate W between the liquid treating chamber  260  and the drying chamber  280 . In the transfer operation S 20 , the transfer unit  244  transfers the substrate W while the mixture liquid supplied in the liquid treating operation S 10  resides on the substrate W. 
     In the mixture liquid drying operation S 30 , a drying operation of removing a mixture solution from the substrate W is performed by supplying the supercritical fluid to the substrate W in the drying chamber  280  and dissolving the mixture liquid supplied in the mixture liquid supplying operation S 10  in the supercritical fluid. 
     According to an embodiment of the inventive concept, a supercritical treatment process time may be shortened. 
     As described above, according to the embodiment of the inventive concept, a drying speed of a mixture liquid obtained by mixing an additive with an organic solvent may become faster as compared with the case in which only an organic solvent is supplied, by performing a drying process using a supercritical fluid. Accordingly, a supercritical process time may be shortened as compared with a case in which only the organic solvent is supplied to the substrate.