Patent Publication Number: US-2021193501-A1

Title: Apparatus for processing substrate

Description:
TECHNICAL FIELD 
     The present disclosure relates to a substrate processing apparatus which performs a processing process such as a deposition process and an etching process on a substrate. 
     BACKGROUND ART 
     Generally, a thin-film layer, a thin-film circuit pattern, or an optical pattern should be formed on a substrate for manufacturing a solar cell, a semiconductor device, a flat panel display device, etc. To this end, a processing process is performed, and examples of the processing process include a deposition process of depositing a thin film including a specific material on a substrate, a photo process of selectively exposing a portion of a thin film by using a photosensitive material, an etching process of removing the selectively exposed portion of the thin film to form a pattern, etc. 
       FIG. 1  is a schematic side cross-sectional view of a related art substrate processing apparatus. 
     Referring to  FIG. 1 , a related art substrate processing apparatus  10  includes a disk  11  which rotates about a rotational shaft  11   a , a distribution unit  12  which distributes a process gas, and a purge unit  13  which distributes a purge gas. 
     The disk  11  rotates a plurality of substrates  20  and  20 ′ with respect to the rotational shaft  11   a  while rotating about the rotational shaft  11   a.    
     The distribution unit  12  distributes the process gas to a plurality of processing regions PA 1  and PA 2 . The processing regions PA 1  and PA 2  are disposed in a path through which the substrates  20  and  20 ′ rotate about the rotational shaft  11   a . The process gas is for performing a processing process such as a deposition process and an etching process. The distribution unit  12  distributes different kinds of process gases to the processing regions PA 1  and PA 2 . 
     The purge unit  13  distributes the purge gas to a center region CA where the rotational shaft  11   a  is disposed. The center region CA is disposed between the processing regions PA 1  and PA 2 . The purge unit  13  distributes the purge gas to the center region CA, and thus, prevents the different kinds of process gases, distributed through the center region CA from the distribution unit  12 , from being mixed with one another. 
     Although not shown, the related art substrate processing apparatus  10  includes a division mechanism which distributes the purge gas so as to divide the processing regions PA 1  and PA 2 . The division mechanism distributes the purge gas to a space between the processing regions PA 1  and PA 2 , and thus, prevents the different kinds of process gases, distributed through the space between the processing regions PA 1  and PA 2  from the distribution unit  12 , from being mixed with one another. 
     Here, when the amount of purge gas distributed to the center region CA by the purge unit  13  is high, the process gas distributed to the processing regions PA 1  and PA 2  by the distribution unit  12  is pushed in an outward direction by the purge gas. When the amount of purge gas distributed to the center region CA by the purge unit  13  is low, the process gas distributed to the processing regions PA 1  and PA 2  by the distribution unit  12  is diffused to the center region CA. The process gas diffused to the center region CA stays in the center region CA and then is pushed in the outward direction by the purge gas and a centrifugal force which acts based on a rotation of the disk  11 , thereby moving to the processing regions PA 1  and PA 2  again. 
     Therefore, in the related art substrate processing apparatus  10 , different process gases are mixed, and different process results are shown between an inner portion close to the center region CA and the other portion in the substrates  20  and  20 ′. Due to this, the related art substrate processing apparatus  10  has a problem where the uniformity of a processing process performed on the substrates  20  and  20 ′ is reduced due to the center region CA which is empty. 
     DISCLOSURE 
     Technical Problem 
     The present inventive concept is devised to solve the above-described problem and is for providing substrate processing apparatuses for enhancing the uniformity of a processing process performed on a substrate. 
     Technical Solution 
     To accomplish the above-described objects, the present inventive concept may include below-described elements. 
     A substrate processing apparatus according to the present inventive concept may include a supporting part for supporting a substrate; a disk supporting a plurality of the supporting parts; a lid disposed on the disk; and a first protrusion portion coupled to the disk to protrude in an upward direction from the disk to the lid in a center region disposed inward from the supporting parts and a gap region disposed between the supporting parts. 
     A substrate processing apparatus according to the present inventive concept may include a supporting part for supporting a substrate; a disk coupled to a plurality of the supporting parts, substrates supported by the supporting parts rotating about a rotational shaft; a lid disposed on the disk; a distribution unit coupled to the lid to distribute a process gas to a plurality of processing regions disposed with respect to the rotational shaft; a purge unit coupled to the lid to distribute a purge gas; and a first protrusion portion coupled to the disk to protrude in an upward direction from the disk to the lid in a center region disposed inward from the supporting parts and a gap region disposed between the supporting parts. 
     Advantageous Effect 
     According to the present inventive concept, the following effects can be obtained. 
     The present inventive concept may be implemented to decrease a size of an empty space in a center region, and thus, may enhance the uniformity of a processing process performed on a substrate. 
     The present inventive concept may be implemented to decrease a size of an empty space between supporting parts, and thus, may more enhance the uniformity of the processing process performed on the substrate. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic side cross-sectional view of a related art substrate processing apparatus. 
         FIG. 2  is a schematic exploded perspective view of a substrate processing apparatus according to the present inventive concept. 
         FIG. 3  is a schematic side cross-sectional view of a supporting part, a disk, and a first protrusion portion each taken along line I-I of  FIG. 2  in a substrate processing apparatus according to the present inventive concept. 
         FIG. 4  is a schematic side cross-sectional view of a substrate processing apparatus according to the present inventive concept. 
         FIG. 5  is a schematic plan view of a supporting part, a disk, and a first protrusion portion in a substrate processing apparatus according to the present inventive concept. 
         FIG. 6  is a schematic side cross-sectional view of a supporting part, a disk, a first protrusion portion, and a distribution unit each taken along line I-I of  FIG. 2  in a substrate processing apparatus according to the present inventive concept. 
         FIG. 7  is a schematic perspective view of a supporting part, a disk, and a first protrusion portion in a substrate processing apparatus according to the present inventive concept. 
         FIG. 8  is a schematic plan view of a portion A of  FIG. 7 . 
         FIG. 9  is a schematic plan view of a first protrusion portion in a substrate processing apparatus according to the present inventive concept. 
         FIGS. 10 and 11  are schematic partial plan views for describing an interval by which a first protrusion portion is spaced apart from supporting parts in a substrate processing apparatus according to the present inventive concept. 
         FIGS. 12 to 14  are schematic partial plan views for describing protrusion members of a first protrusion portion in a substrate processing apparatus according to the present inventive concept. 
         FIG. 15  is a schematic exploded perspective view for describing a second protrusion portion in a substrate processing apparatus according to the present inventive concept. 
         FIG. 16  is a schematic plan view of a supporting part, a disk, a first protrusion portion, and a second protrusion portion in a substrate processing apparatus according to the present inventive concept. 
         FIGS. 17 and 18  are schematic side cross-sectional views of a supporting part, a disk, a first protrusion portion, and a second protrusion portion each taken along line I-I of  FIG. 2  in a substrate processing apparatus according to the present inventive concept. 
         FIG. 19  is a schematic side cross-sectional view of a second protrusion portion taken along line I-I of  FIG. 2  in a substrate processing apparatus according to a modified embodiment of the present inventive concept. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment of a substrate processing apparatus according to the present inventive concept will be described in detail with reference to the accompanying drawings. 
     Referring to  FIG. 2 , a substrate processing apparatus  1  according to the present inventive concept performs a processing process on a substrate S. For example, the substrate processing apparatus  1  according to the present inventive concept may perform at least one of a deposition process of depositing a thin film on the substrate S and an etching process of removing a portion of the thin film deposited on the substrate S. The substrate processing apparatus  1  according to the present inventive concept includes a supporting part  2 , a disk  3 , a lid  4 , a distribution unit  5 , a purge unit  6 , and a first protrusion portion  7 . 
     Referring to  FIGS. 2 to 4 , the supporting part  2  supports the substrate S. The substrate S may be placed in the supporting part  2 , and thus, may be supported by the supporting part  2 . The substrate S may be a semiconductor substrate or a wafer. 
     The supporting part  2  may include a supporting groove  21  and a supporting wall  22 . 
     The substrate S is inserted into the supporting groove  21 . The supporting groove  21  may be provided in an upper surface of the supporting part  2 . The supporting groove  21  may be formed by processing a groove by a certain depth in the upper surface of the supporting part  2 . The substrate S may be inserted into the supporting groove  21  and may be supported by the supporting part  2 . The supporting groove  21  and the substrate S may be provided to have a shape and a size each matching each other. 
     The supporting wall  22  is disposed to surround the supporting groove  21 . When the substrate S is inserted into the supporting groove  21 , the substrate S may be disposed in an inner portion of the supporting wall  22 . When the substrate S is inserted into the supporting groove  21 , an upper surface of the substrate S and an upper surface of the supporting wall  22  may be disposed to have the same height as illustrated in  FIG. 3 . In this case, the upper surface of the substrate S supported by the supporting part  2  and the upper surface of the supporting wall  22  may be spaced apart from an upper surface  3   a  of the disk  3  by the same height. 
     Referring to  FIGS. 2 to 5 , the disk  3  supports a plurality of substrates S. The disk  3  may be coupled to an inner portion of a chamber  110  which provides a processing space where the processing process is performed. A substrate entrance  111  (illustrated in  FIG. 4 ) may be coupled to the chamber  110 . The substrates S may pass through the substrate entrance  111  and may be loaded into the chamber  110  by a loading apparatus (not shown). When the processing process is completed, the substrates S may pass through the substrate entrance  111  and may be unloaded to the outside of the chamber  110  by an unloading apparatus (not shown). An exhaust unit  112  (illustrated in  FIG. 4 ) for exhausting a gas, remaining in the processing space, to the outside may be coupled to the chamber  110 . 
     A plurality of supporting parts  2  may be coupled to the disk  3 . When the substrates S are supported by the supporting parts  2 , the disk  3  may support the supporting parts  2  to support the substrates S. The supporting parts  2  may be coupled to the disk  3  so as to protrude in an upward direction UD (an arrow direction) from the upper surface  3   a  of the disk  3 . Therefore, upper surfaces of the substrates S supported by the supporting parts  2  may be disposed at positions spaced apart from the upper surface  3   a  of the disk  3  in the upward direction UD (the arrow direction). The supporting parts  2  may support the substrates S so that the upper surfaces of the substrates S are spaced apart from the upper surface  3   a  of the disk  3  by a first height H 1  (illustrated in  FIG. 3 ) in the upward direction UD (the arrow direction). In this case, each of the supporting parts  2  may protrude by the first height H 1  in the upward direction UD (the arrow direction) from the upper surface  3   a  of the disk  3 . 
     The disk  3  may rotate about a rotational shaft  3   b  (illustrated in  FIG. 5 ). The disk  3  may rotate in a first rotational direction R 1  (an arrow direction) (illustrated in  FIG. 5 ). The first rotational direction R 1  (the arrow direction) may be a clockwise direction or a counterclockwise direction with respect to the rotational shaft  3   b . The supporting parts  2  may be coupled to the disk  3  so as to be spaced apart from one another at the same angle in the first rotational direction R 1  (the arrow direction) with respect to the rotational shaft  3   b . In  FIGS. 2 and 5 , six supporting parts  2  are illustrated as being coupled to the disk  3 , but are not limited thereto. Two, three, four, five, or seven or more supporting parts  2  may be coupled to the disk  3 . 
     As the disk  3  rotates about the rotational shaft  3   b , the substrates S supported by the supporting parts  2  may rotate about the rotational shaft  3   b . In this case, the substrates S supported by the supporting parts  2  may revolve about the rotational shaft  3   b . The disk  3  may be coupled to a driver  120  (illustrated in  FIG. 4 ) which provides a rotational force. Each of the supporting parts  2  may be rotatably coupled to the disk  3 . In this case, each of the supporting parts  2  may rotate about a rotational shaft thereof. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the processing process is performed on the substrates S supported by the supporting parts  2  while the substrates S are rotating and revolving. 
     Referring to  FIGS. 2 to 5 , the lid  4  is disposed on the disk  3 . The lid  4  may be coupled to the chamber  110  to cover an upper portion of the chamber  110 . The lid  4  and the chamber  110  may be provided in a cylindrical structure as illustrated in  FIG. 2 , but are not limited thereto and may be provided in an elliptical structure, a polygonal structure, or the like. 
     The lid  4  may be disposed apart from the disk  3  in the upward direction UD (the arrow direction). The lid  4  may support the distribution unit  5  and the purge unit  6 . Each of the distribution unit  5  and the purge unit  6  may be disposed apart from the disk  3  in the upward direction UD (the arrow direction) and may be coupled to the lid  4 . Referring to  FIGS. 2 to 6 , the distribution unit distributes a process gas. The distribution unit  5  may be disposed apart from the disk  3  in the upward direction UD (the arrow direction). Therefore, the distribution unit  5  may distribute the process gas in a downward direction DD (an arrow direction) toward the disk  3 . The distribution unit  5  may be coupled to the lid  4 . The distribution unit  5  may distribute the process gas to a processing region PA (illustrated in  FIG. 5 ). Accordingly, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that a processing process using the process gas is performed on a substrate S located in the processing region PA. When the substrates S rotate about the rotational shaft  3   b , the distribution unit  5  may distribute the process gas to a plurality of processing regions PA 1  and PA 2  (illustrated in  FIG. 5 ) disposed along a rotational path through which the substrates S rotate. The rotational path denotes a path through which the supporting parts  2  pass while rotating about the rotational shaft  3   b  of the disk  3 . In this case, the substrates S may sequentially pass through the processing regions PA 1  and PA 2  while rotating along the rotational path. 
     The distribution unit  5  may include a distribution hole  51  (illustrated in  FIG. 6 ). 
     The distribution unit  5  may distribute the process gas in the downward direction DD (an arrow direction) toward the disk  3  through the distribution hole  51 . The distribution unit  5  may be coupled to the lid  4  so that a lower end  510  (illustrated in  FIG. 6 ) of the distribution hole  51  is disposed at a position spaced apart from the disk  3  in the upward direction UD (the arrow direction). The distribution unit  5  may include a plurality of distribution holes  51 . In this case, the distribution holes  51  may be disposed apart from one another. 
     The distribution unit  5  may include a first distribution mechanism  52  (illustrated in  FIG. 2 ) and a second distribution mechanism  53  (illustrated in  FIG. 2 ). 
     The first distribution mechanism  52  distributes a source gas among process gases. The first distribution mechanism  52  may be coupled to the lid  4  so as to be disposed on the disk  3 . The first distribution mechanism  52  may distribute the source gas to a first processing region PA 1  (illustrated in  FIG. 5 ). The first processing region PA 1  corresponds to a portion of a processing space disposed between the distribution unit  5  and the disk  3 . When the disk  3  rotates about the rotational shaft  3   b , the substrates S supported by the disk  3  may sequentially pass through the first processing region PA 1  while rotating about the rotational shaft  3   b . Therefore, a processing process using the source gas may be performed on substrates S passing through the first processing region PAL Although not shown, the distribution unit  5  may include a plurality of first distribution mechanisms  52 . In this case, the first distribution mechanisms  52  may be disposed at positions spaced apart from one another long the rotational path. 
     The second distribution mechanism  53  distributes a reactant gas among the process gases. The second distribution mechanism  53  may be coupled to the lid  4  so as to be disposed on the disk  3 . The second distribution mechanism  53  may distribute the reactant gas to a second processing region PA 2  (illustrated in  FIG. 5 ). The second processing region PA 2  corresponds to a portion of the processing space disposed between the distribution unit  5  and the disk  3 . The second processing region PA 2  and the first processing region PA 1  may be disposed at different positions along the rotational path. When the disk  3  rotates about the rotational shaft  3   b , the substrates S supported by the disk  3  may sequentially pass through the second processing region PA 2  while rotating about the rotational shaft  3   b . Therefore, a processing process using the reactant gas may be performed on substrates S passing through the second processing region PA 2 . Although not shown, the distribution unit  5  may include a plurality of second distribution mechanisms  53 . In this case, the second distribution mechanisms  53  may be disposed at positions spaced apart from one another long the rotational path. 
     Referring to  FIGS. 2 to 6 , the purge unit  6  (illustrated in  FIG. 2 ) distributes a purge gas. The purge unit  6  may be disposed on the disk  3 . Therefore, the purge unit  6  may distribute the purge gas in the downward direction DD (the arrow direction) toward the disk  3 . The purge unit  6  may be coupled to the lid  4 . 
     The purge unit  6  may distribute the purge gas to a center region CA (illustrated in  FIG. 5 ). The center region CA may be disposed between the processing regions PA 1  and PA 2 . In this case, the purge unit  6  may be disposed at a position spaced apart from the rotational shaft  3   b  of the disk  3  in the upward direction UD (the arrow direction). The purge unit  6  may distribute the purge gas to the center region CA, and thus, may prevent different kinds of process gases, distributed through the center region CA from the distribution unit  5 , from being mixed. When the distribution unit  5  distributes the source gas and the reactant gas, the purge unit  6  may distribute the purge gas to the center region CA so that the source gas and the reactant gas are not mixed through the center region CA. In this case, the purge unit  6  may be disposed between the first distribution mechanism  52  and the second distribution mechanism  53 . The purge unit  6  may distribute the purge gas to the center region CA to exhaust a process gas remaining in and around the center region CA. The center region CA may be implemented in a circular shape where a distance from a middle point of a separation space between the first distribution mechanism  52  and the purge unit  6  is a radius. 
     Referring to  FIGS. 2 to 7 , the first protrusion portion  7  may be coupled to the disk  3  to protrude in the upward direction UD (the arrow direction) from the disk  3 . A portion of the first protrusion portion  7  may be disposed in the center region CA. The other portion of the first protrusion portion  7  may extend from a portion of the first protrusion portion  7  disposed in the center region CA so as to be disposed in a region (hereinafter referred to as a gap region) between the supporting parts  2 . In this case, the gap region may be a space which is disposed between the supporting parts  2  as the supporting parts  2  are spaced apart from each other at a certain angle with respect to the rotational shaft  3   b  of the disk  3 . Therefore, the first protrusion portion  7  may be disposed to protrude from the disk  3  in the center region CA and the gap region. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may obtain the following effects. 
     First, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that a portion of the first protrusion portion  7  protrudes in the upward direction UD (the arrow direction) from the disk  3  in the center region CA, and thus, a size of an empty space in the center region CA may decrease by a volume of the first protrusion portion  7  disposed in the center region CA. Therefore, the substrate processing apparatus  1  according to the present inventive concept may decrease a size of a space which enables a processing gas, including at least one of the process gas distributed by the distribution unit  5  and the purge gas distributed by the purge unit  6 , to stay in the center region CA. Therefore, the substrate processing apparatus  1  according to the present inventive concept may decrease a degree of deviation of a process result which occurs between inner portions and the other portions of the substrates S due to the processing gas remaining in the center region CA. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may enhance the uniformity of a processing process performed on a substrate. The inner portions of the substrates S are portions close to the center region CA. 
     Second, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the other portion of the first protrusion portion  7  protrudes in the upward direction UD (the arrow direction) from the disk  3  in the gap region, and thus, a size of an empty space in the gap region may decrease by a volume of the first protrusion portion  7  disposed in the gap region. Therefore, the substrate processing apparatus  1  according to the present inventive concept may decrease a size of a space which enables the processing gas to stay in the gap region. Therefore, the substrate processing apparatus  1  according to the present inventive concept may decrease a degree of deviation of a processing rate, such as a deposition rate or an etching rate, which occurs partially in the substrates S due to the processing gas staying in the gap region. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may more enhance the uniformity of a processing process performed on a substrate. 
     Third, the substrate processing apparatus  1  according to the present inventive concept may decrease a size of an empty space in the center region CA, and thus, may decrease a size of a space to which the purge gas is to be distributed by the purge unit  6 , for preventing different kinds of process gases from being mixed through the center region CA. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may reduce the amount of purge gas distributed by the purge unit  6 , thereby reducing the operating cost. 
     Referring to  FIGS. 2 to 8 , the first protrusion portion  7  may protrude in the upward direction UD (the arrow direction) from the upper surface  3   a  of the disk  3  at a position spaced apart from the supporting parts  2 . Therefore, a gas groove  70  (illustrated in  FIG. 8 ) may be disposed between the first protrusion portion  7  and the supporting parts  2 . The gas groove  70  may be a space which is disposed between the first protrusion portion  7  and the supporting parts  2  to contact the upper surface  3   a  of the disk  3  and may be implemented in a shape such as a valley between the first protrusion portion  7  and the supporting parts  2 . A residual gas including at least one of the purge gas distributed by the purge unit  6  and the process gas distributed by the distribution unit  5  may flow along the gas groove  70  and may be exhausted to the outside of the chamber  110 . 
     Therefore, the substrate processing apparatus  1  according to the present inventive concept is implemented to smoothly exhaust a residual gas through the gas groove  70 . Also, the substrate processing apparatus  1  according to the present inventive concept is implemented so that the first protrusion portion  7  and the supporting parts  2  protrude in the upward direction UD (the arrow direction) from the upper surface  3   a  of the disk  3 , and thus, by using the first protrusion portion  7  and the supporting parts  2 , the residual gas exhausted through the gas groove  70  is prevented from penetrating into the substrate S. In this case, an outer surface, disposed to face the gas groove  70 , of each of the first protrusion portion  7  and the supporting parts  2  may function as a barrier which prevents the residual gas from penetrating into the substrate S. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may decrease a degree of deviation of a processing rate, such as a deposition rate or an etching rate, which occurs partially in the substrates S due to the residual gas, thereby more enhancing the uniformity of a processing process performed on a substrate. 
     The first protrusion portion  7  may protrude by a second height H 2  (illustrated in  FIG. 3 ) in the upward direction UD (the arrow direction) from the upper surface  3   a  of the disk  3 . In this case, the supporting parts  2  may support the substrates S so that upper surfaces of the substrates S are spaced apart from each other by the first height H 1  (illustrated in  FIG. 3 ) in the upward direction UD (the arrow direction) from the upper surface  3   a  of the disk  3 . The second height H 2  and the first height H 1  may be implemented identically. That is, an upper surface of the first protrusion portion  7  and the upper surfaces of the substrate S supported by the supporting parts  2  may be disposed at the same position. Therefore, the residual gas exhausted through the gas groove  70  is implemented so that a restraint force (hereinafter referred to as a restraint force of the first protrusion portion  7 ) for preventing the residual gas exhausted through the gas groove  70  from penetrating into the upper surface of the first protrusion portion  7  is approximately equal to a restraint force (hereinafter referred to as a restraint force of the substrates S) for preventing the residual gas exhausted through the gas groove  70  from penetrating into the upper surfaces of the substrates S supported by the supporting parts  2 . This will be described below in detail. 
     First, when the upper surface of the first protrusion portion  7  has a height which is lower in position than the upper surfaces of the substrates S supported by the supporting parts  2 , an outer surface of the first protrusion portion  7  facing the gas groove  70  is implemented to have a height which is lower in position than outer surfaces of the substrates S facing the gas groove  70 . Therefore, a distance by which the residual gas exhausted through the gas groove  70  should be raised for penetrating into the upper surface of the first protrusion portion  7  is implemented to be shorter than a distance by which the residual gas exhausted through the gas groove  70  should be raised for penetrating into the upper surfaces of the substrates S supported by the supporting parts  2 . That is, the restraint force of the first protrusion portion  7  is implemented to be less than the restraint force of the substrates S. Accordingly, the residual gas exhausted through the gas groove  70  may move to the upper surface of the first protrusion portion  7  which is relatively less in restraint force, and thus, an exhaust force may be reduced. 
     Next, on the other hand, when the upper surfaces of the substrates S supported by the supporting parts  2  have a height which is lower in position than the upper surface of the first protrusion portion  7 , the restraint force of the substrates S is implemented to be less than the restraint force of the first protrusion portion  7 . Accordingly, the residual gas exhausted through the gas groove  70  may move to the upper surfaces of the substrates S which is relatively less in restraint force, and thus, an exhaust force may be reduced. 
     Next, when the upper surfaces of the substrates S supported by the supporting parts  2  have the same height as that of the upper surface of the first protrusion portion  7 , the restraint force of the substrates S and the restraint force of the first protrusion portion  7  are implemented to be approximately equal. Therefore, a degree to which the residual gas exhausted through the gas groove  70  concentrates on one of the upper surface of the first protrusion portion  7  and the upper surfaces of the substrates S may be reduced. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the residual gas does not deviate from the gas groove  70  and is exhausted by smoothly moving along the gas groove  70 . 
     Referring to  FIGS. 8 and 9 , the first protrusion portion  7  may include a plurality of accommodating grooves  71  (illustrated in  FIG. 9 ). 
     Each of the accommodating grooves  71  accommodates a portion of a corresponding supporting part of the supporting parts  2  (illustrated in  FIG. 8 ). Each of the accommodating grooves  71  may be formed to be concave along a shape of the supporting part  2 . Therefore, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the first protrusion portion and each of the supporting parts  2  are disposed apart from each other by a uniform interval. That is, the gas groove  70  may be formed so that cross-sectional surfaces having a uniform size are arranged along a shape of the supporting part  2 . Accordingly, the substrate processing apparatus  1  according to the present inventive concept may decrease a possibility that the residual gas exhausted through the gas groove  70  disposed between the first protrusion portion  7  and each of the supporting parts  2  stays. 
     Outer surfaces of the first protrusion portion  7  which are disposed to face the accommodating grooves  71  and outer surfaces of the supporting parts  2  which are disposed to face the accommodating grooves  71  may be formed to each configure a curve surface. In the supporting parts  2 , with respect to a direction toward the first protrusion portion  7 , the outer surfaces of the first protrusion portion  7  may be formed as a concavely curve surface, and the outer surfaces of the supporting parts  2  may be formed as a convexly curve surface. Therefore, the outer surfaces of the first protrusion portion  7  and the outer surfaces of the supporting parts  2  may induce the residual gas located in the gas groove  70  to be smoothly exhausted. For example, as illustrated by a dotted-line arrow in  FIG. 8 , the residual gas located in the gas groove  70  may flow along a curve surface configured by the outer surfaces of the first protrusion portion  7  and the outer surfaces of the supporting parts  2 , and thus, may be smoothly exhausted. In  FIG. 9 , six accommodating grooves  71  are illustrated as being formed in the first protrusion portion  7  but are not limited thereto, and two, three, four, five, or seven or more accommodating grooves  71  may be formed in the first protrusion portion  7 . In this case, the number of the accommodating grooves  71  and the number of the supporting parts  2  may be implemented equally. 
     Referring to  FIGS. 10 and 11 , the first protrusion portion  7  may include a first accommodating groove  71   a  and a second accommodating groove  71   b.    
     The first accommodating groove  71   a  accommodates a portion of a first supporting part  2   a . The first accommodating groove  71   a  may correspond to one of the accommodating grooves  71  included in the first protrusion portion  7 . The first supporting part  2   a  may correspond to one of the supporting parts  2  coupled to the disk  3 . The first supporting part  2   a  accommodated into the first accommodating groove  71   a  and the first protrusion portion  7  may be disposed apart from each other by a first interval D 1 . The first interval D 1  may denote a distance by which an outer surface of the first supporting part  2   a  disposed to face the first accommodating groove  71   a  and an outer surface of the first protrusion portion  7  disposed to face the first accommodating groove  71   a  are spaced apart from each other. The first interval D 1  may denote a distance with respect to a first connection line L 1  which connects the rotational shaft  3   b  of the disk  3  to a center  20   a  of the first supporting part  2   a . The first supporting part  2   a  and the first protrusion portion  7  may be disposed to be uniformly spaced apart from each other by the first interval D 1 . 
     The second accommodating groove  71   b  accommodates a portion of a second supporting part  2   b . The second accommodating groove  71   b  may correspond to one of the accommodating grooves  71  included in the first protrusion portion  7 . The second supporting part  2   b  may correspond to one of the supporting parts  2  coupled to the disk  3 . The second supporting part  2   b  accommodated into the second accommodating groove  71   b  and the first protrusion portion  7  may be disposed apart from each other by a second interval D 2 . The second interval D 2  may denote a distance by which an outer surface of the second supporting part  2   b  disposed to face the second accommodating groove  71   b  and an outer surface of the first protrusion portion  7  disposed to face the second accommodating groove  71   b  are spaced apart from each other. The second interval D 2  may denote a distance with respect to a second connection line L 2  which connects the rotational shaft  3   b  of the disk  3  to a center  20   b  of the second supporting part  2   b . The second supporting part  2   b  and the first protrusion portion  7  may be disposed to be uniformly spaced apart from each other by the second interval D 2 . 
     As illustrated in  FIG. 10 , the second interval D 2  and the first interval D 1  may be implemented identically. In this case, the second supporting part  2   b  and the first supporting part  2   a  may be disposed at positions spaced apart from the first protrusion portion  7  by the same distance. Therefore, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that a processing process is performed in a process environment where a substrate S supported by the second supporting part  2   b  approximately matches a substrate S supported by the first supporting part  2   a . Although not shown, all of the supporting parts  2  may be disposed at positions spaced apart from the first protrusion portion  7  by the same distance. 
     As illustrated in  FIG. 11 , the second interval D 2  and the first interval D 1  may be implemented differently. In this case, the second supporting part  2   b  and the first supporting part  2   a  may be disposed at positions spaced apart from the first protrusion portion  7  by different distances. Therefore, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that a processing process is performed in a process environment where a substrate S supported by the second supporting part  2   b  differs from a substrate S supported by the first supporting part  2   a . When the substrate S supported by the second supporting part  2   b  and the substrate S supported by the first supporting part  2   a  have different kinds and different specifications, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the second interval D 2  differs from the first interval D 1 , thereby enhancing the uniformity of a processing process performed on the substrates S. 
     For example, the second interval D 2  may be implemented to be shorter than the first interval D 1 . In this case, the second supporting part  2   b  may be disposed at a position spaced apart from the first protrusion portion  7  by a distance which is shorter than the first supporting part  2   a . Although not shown, all of the supporting parts  2  may be disposed at positions spaced apart from the first protrusion portion  7  by different distances. Although not shown, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the supporting parts  2  spaced apart from the first protrusion portion  7  by different distances match the supporting parts  2  spaced apart from the first protrusion portion  7  by the same distance. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may enhance a general purpose capable of being applied to various substrates, various processing processes, etc. 
     Referring to  FIGS. 12 to 14 , the first protrusion portion  7  may include a center plate  72  and a plurality of protrusion members  73 . 
     The center plate  72  protrudes in the upward direction UD (the arrow direction) from the center region CA. Therefore, the center plate  72  may decrease a size of an empty space in the center region CA, thereby reducing a size of a space enabling the processing gas to stay in the center region CA. The center plate  72  may configure a portion of the first protrusion portion  7 . The center plate  72  may be coupled to the disk  3  to form a concentric circle with the disk  3 . In this case, a center  72   a  of the center plate  72  and the rotational shaft  3   b  (illustrated in  FIG. 11 ) of the disk  3  may be disposed at the same positions. 
     The center plate  72  may be disposed apart from the supporting parts  2  by a certain distance. Therefore, the gas grooves  70  may be disposed between the center plate  72  and the supporting parts  2 . The center plate  72  and the supporting parts  2  may be implemented to protrude from the upper surface  3   a  of the disk  3 , and thus, may prevent the residual gas exhausted through the gas groove  70  from penetrating into the center region CA and the substrates S supported by the supporting parts  2 . 
     The protrusion members  73  extend in an outward direction from the center plate  72  to a region between the supporting parts  2 . Therefore, the protrusion members  73  may be disposed between the supporting parts  2 . That is, the protrusion members  73  may be disposed in the gap region. The protrusion members  73  may protrude in the upward direction UD (the arrow direction) in the gap region. Therefore, the protrusion members  73  may decrease a size of an empty space in the gap region, thereby reducing a size of a space enabling the processing gas to stay in the gap region. The protrusion members  73  may configure a portion of the first protrusion portion  7 . The protrusion members  73  may be coupled to the center plate  72 . The protrusion members  73  and the first protrusion portion  7  may be provided as one body. 
     The protrusion members  73  may be disposed apart from the supporting parts  2  by a certain distance in the gap region. Therefore, the gas grooves  70  may be disposed between the protrusion members  73  and the supporting parts  2 . The protrusion members  73  and the supporting parts  2  may be implemented to protrude from the upper surface  3   a  of the disk  3 , and thus, the residual gas exhausted through the gas groove  70  may prevent from penetrating into upper portions of the protrusion members  73  and the substrates S supported by the supporting parts  2 . 
     In  FIGS. 12 to 14 , six protrusion members  73  are illustrated as being coupled to the center plate  72  but are not limited thereto, and two, three, four, five, or seven or more protrusion members  73  may be coupled to the center plate  72 . In this case, the number of the protrusion members  73  and the number of the supporting parts  2  may be implemented equally. 
     As illustrated in  FIG. 12 , each of the protrusion members  73  may be provided so that an end portion  73   a  thereof is disposed in a rotational radius R. In this case, with respect to the center  72   a  of the center plate  72 , a length  73 D of the protrusion member  73  and the rotational radius R may be implemented equally. The end portion  73   a  of each of the protrusion members  73  is a portion which is spaced apart from the center  72   a  of the center plate  72  by a longest distance in the outward direction. The rotational radius R denotes a distance by which the center  20  of each of the supporting parts  2  is spaced apart from the center  72   a  of the center plate  72 . In this case, the supporting parts  2  may be coupled to the disk  3  so that the center  20  of each of the supporting parts  2  is spaced apart from the center  72   a  of the center plate  72  by the rotational radius R. The end portions  73   a  of the protrusion members  73  may be disposed in a virtual radius circle RC which connects the centers  20  of the supporting parts  2  with respect to the center  72   a  of the center plate  72 . 
     As illustrated in  FIG. 13 , the protrusion members  73  may be provided so that the end portions  73   a  thereof are disposed in the rotational radius R. In this case, with respect to the center  72   a  of the center plate  72 , the length  73 D of the protrusion member  73  may be implemented to be shorter than the rotational radius R. Therefore, with respect to the center  72   a  of the center plate  72 , the end portions  73   a  of the protrusion members  73  may be disposed in the virtual radius circle RC which connects the centers  20  of the supporting parts  2 . In this case, the protrusion members  73  may be provided so that the end portions  73   a  thereof are disposed at a distance which is 0.9 or more times the rotational radius R. Therefore, with respect to the center  72   a  of the center plate  72 , the length  73 D of the protrusion member  73  may be implemented to be 0.9 or more times the rotational radius R. 
     As illustrated in  FIG. 14 , the protrusion members  73  may be provided so that the end portions  73   a  thereof are disposed outside the rotational radius R. In this case, with respect to the center  72   a  of the center plate  72 , the length  73 D of the protrusion member  73  may be implemented to be longer than the rotational radius R. Therefore, with respect to the center  72   a  of the center plate  72 , the end portions  73   a  of the protrusion members  73  may be disposed outside the virtual radius circle RC which connects the centers  20  of the supporting parts  2 . In this case, the protrusion members  73  may be provided so that the end portions  73   a  thereof are disposed at a distance which is 1.1 or less times the rotational radius R. Therefore, with respect to the center  72   a  of the center plate  72 , the length  73 D of the protrusion member  73  may be implemented to be 1.1 or less times the rotational radius R. 
     As illustrated in  FIGS. 12 to 14 , the protrusion members  73  may be provided so that the end portions  73   a  thereof are disposed at a distance which is 0.9 to 1.1 times the rotational radius R. In this case, with respect to the center  72   a  of the center plate  72 , the length  73 D of the protrusion member  73  may be implemented to be 0.9 to 1.1 times the rotational radius R. 
     The protrusion members  73 , the center plate  72 , and the disk  3  may be formed of the same material. The protrusion members  73  and the center plate  72  may be formed of the same material, and the disk  3  and the center plate  72  may be formed of different materials. 
     Referring to  FIGS. 2 to 17 , the substrate processing apparatus  1  according to the present inventive concept may include a second protrusion portion  8 . 
     The second protrusion portion  8  protrudes from the first protrusion portion  7 . The second protrusion portion  8  may protrude from the upper surface of the first protrusion portion  7  in the upward direction UD (the arrow direction) in the center region CA. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may obtain the follow effects. 
     First, the substrate processing apparatus  1  according to the present inventive concept is implemented so that the first protrusion portion  7  protrudes in the upward direction UD (the arrow direction) from the upper surface of the disk  3 , and additionally, the second protrusion portion  8  protrudes in the upward direction UD (the arrow direction) from the upper surface of the first protrusion portion  7 . Therefore, in the substrate processing apparatus  1  according to the present inventive concept, a size of an empty space in the center region CA may decrease by a volume corresponding to a sum of a volume of the first protrusion portion  7  and a volume of the second protrusion portion  8 . Accordingly, in the substrate processing apparatus  1  according to the present inventive concept, a size of a space enabling the processing gas to stay in the center region CA may be further reduced, thereby more enhancing the uniformity of a processing process performed on a substrate. 
     Second, in the substrate processing apparatus  1  according to the present inventive concept, a size of an empty space in the center region CA may be further reduced by using the first protrusion portion  7  and the second protrusion portion  8 , and thus a size of a space to which the purge gas is to be distributed by the purge unit  6 , for preventing different kinds of process gases from being mixed through the center region CA. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may more reduce the amount of purge gas distributed by the purge unit  6 , thereby reducing the operating cost. 
     Third, in a comparative example where the second protrusion portion  8  protrudes from the lid  4 , a size of an empty space in the center region CA may be reduced. However, in the comparative example, a communication space which communicates the processing regions PA 1  and PA 2  is disposed as the second protrusion portion  8  and the first protrusion portion  7  are spaced apart from each other in a direction in which the distribution unit  5  downward distributes a process gas. Therefore, in the comparative example, a distributive force with which the distribution unit  5  downward distributes the process gas acts as a force for passing through the communication space, and thus, there is a risk where different kinds of process gases are mixed through the communication space. In order to prevent the risk, the amount of purge gas distributed by the purge unit  6  should increase. 
     On the other hand, the substrate processing apparatus  1  according to the present inventive concept is implemented so that the second protrusion portion  8  protrudes in the upward direction UD (the arrow direction) from the first protrusion portion  7 , and thus, a communication space like the comparative example is not provided in the direction in which the distribution unit  5  downward distributes the process gas. Therefore, comparing with the comparative example, the substrate processing apparatus  1  according to the present inventive concept may use the second protrusion portion  8  to decrease a risk where different kinds of process gases are mixed, and moreover, may prevent mixing of different kinds of process gases with a relatively low amount of distributed purge gas. Also, in the substrate processing apparatus  1  according to the present inventive concept, the distributive force with which the distribution unit  5  downward distributes the process gas acts as a force which returns the process gas to an outer portion of the center region CA. This is because a distributive force remaining after the process gas is blocked by the second protrusion portion  8  act as a force which returns the process gas to the outer portion of the center region CA. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may use the distributive force, with which the distribution unit  5  downward distributes the process gas, as a preventive force which prevents the process gas from staying in the center region CA. 
     The second protrusion portion  8  may be provided in a cylindrical shape which protrudes in the upward direction UD (the arrow direction) from the first protrusion portion  7  in the center region CA, but is not limited thereto and may be provided in an arbitrary shape for decreasing a size of an empty space in the center region CA. The second protrusion portion  8  and the first protrusion portion  7  may be provided as one body. 
     The second protrusion portion  8  may be formed of an insulating material. Therefore, in the substrate processing apparatus  1  according to the present inventive concept, in a case where a deposition process is performed on the substrates S, a thin film may be prevented from being unnecessarily deposited on the second protrusion portion  8 . Therefore, in the substrate processing apparatus  1  according to the present inventive concept, the quality of a substrate S on which the deposition process is completed may be prevented from being degraded due to the thin film deposited on the second protrusion portion  8 , and moreover, a cleaning period of the second protrusion portion  8  may increase. For example, the second protrusion portion  8  may be formed of ceramic. 
     The second protrusion portion  8  and the disk  3  may be formed of different materials. That is, the second protrusion portion  8  and the disk  3  may be formed of different kinds of materials. For example, when the disk  3  is formed of a conductive material, the second protrusion portion  8  may be formed of an insulating material. In this case, the disk  3  may be formed of aluminum (Al), and the second protrusion portion  8  may be formed of ceramic. Therefore, in a case where a deposition process is performed on the substrates S, the substrate processing apparatus  1  according to the present inventive concept may induce a thin film to be deposited on a substrate S supported by the disk  3  and simultaneously may prevent a thin film from being unnecessarily deposited on the second protrusion portion  8 . The second protrusion portion  8  and the first protrusion portion  7  may be formed of the same material. 
     The second protrusion portion  8  may be detachably coupled to the first protrusion portion  7 . Therefore, in the substrate processing apparatus  1  according to the present inventive concept, in a case where a process condition such as a size of the substrate S or the kind of the processing process is changed and thus it is required to adjust a size of an empty space in the center region CA, a responding force corresponding to a changed process condition may be enhanced by replacing the second protrusion portion  8 . For example, the second protrusion portion  8  may be detachably coupled to the first protrusion portion  7  by using a fastening means such as a bolt. 
     When the second protrusion portion  8  is disposed in the center region CA, the purge unit  6  may be coupled to the lid  4  so as to be disposed in the upward direction UD (the arrow direction) with respect to the second protrusion portion  8 . Therefore, the purge unit  6  may downward distribute the purge gas toward the second protrusion portion  8 . The purge gas downward distributed toward the second protrusion portion  8  by the purge unit  6  may prevent mixing of different kinds of process gases while staying in a space disposed between the purge unit  6  and the second protrusion portion  8 . Also, the purge gas downward distributed toward the second protrusion portion  8  by the purge unit  6  may be induced to move to the first protrusion portion  7  along an outer surface of the second protrusion portion  8 . Accordingly, the substrate processing apparatus  1  according to the present inventive concept may exhaust a process gas remaining in the center region CA by using the purge gas which has moved to the first protrusion portion  7 . 
     The second protrusion portion  8  may protrude in the upward direction UD (the arrow direction) from the first protrusion portion  7  so that an upper end  80  (illustrated in  FIG. 17 ) thereof is disposed at a position which is higher than a lower end  510  of the distribution hole  51 . That is, a height  8 H (illustrated in  FIG. 17 ) of the upper end  80  of the second protrusion portion  8  is higher than a height  510 H (illustrated in  FIG. 17 ) of the lower end  510  of the distribution hole  51 . Therefore, the substrate processing apparatus  1  according to the present inventive concept is implemented so that the distribution unit  5  downward distributes a process gas at a height which is lower in position than the upper end  80  of the second protrusion portion  8 . Therefore, the process gas distributed by the distribution unit  5  may be raised in a reverse direction of a direction in which gravity acts, and thus, may pass through the second protrusion portion  8 . Accordingly, the substrate processing apparatus  1  according to the present inventive concept may more enhance a preventive force which prevents mixing of different process gases. 
     Referring to  FIGS. 2 to 18 , the second protrusion portion  8  may protrude in the upward direction UD (the arrow direction) from an upper surface of the center plate  72 . The second protrusion portion  8  may be provided to have a size which is less than that of the center plate  72 . Therefore, the second protrusion portion  8  may be disposed inward from the center plate  72 . In this case, the center plate  72  may be disposed in a shape which protrudes from the second protrusion portion  8  to the outside. 
     The second protrusion portion  8  may be disposed at a position spaced apart from the supporting parts  2 . In this case, the center plate  72  may be provided to protrude by a first distance FD (illustrated in  FIG. 18 ) from the second protrusion portion  8  with respect to a virtual center connection line CL (illustrated in  FIG. 8 ) which connects a center  72   a  (illustrated in  FIG. 16 ) of the center plate  72  to a center  20  (illustrated in  FIG. 16 ) of each of the supporting parts  2 . Each of the supporting parts  2  may be disposed apart from the center plate  72  by a second distance SD (illustrated in  FIG. 18 ) with respect to the center connection line CL. The second distance SD may be implemented to be equal to or shorter than the first distance FD. That is, the first distance FD is not implemented to be shorter than the second distance SD. Accordingly, the substrate processing apparatus  1  according to the present inventive concept may decrease a degree of deviation of a processing rate, such as a deposition rate or an etching rate, which occurs partially in the substrates S due to the purge gas distributed by the purge unit  6 . This will be described below in detail. 
     First, in the comparative example where the first distance FD is implemented to be shorter than the second distance SD, a distance by which the center plate  72  protrudes from the second protrusion portion  8  to the outside is implemented to be shorter than a distance by which the center plate  72  is spaced apart from the supporting parts  2 . In a process where the purge gas distributed by the purge unit  6  flows to the supporting parts  2  via the second protrusion portion  8  and the center plate  72 , a distance by which the purge gas flows along the center plate  72  is shortened. Therefore, an elbow period TD (illustrated in  FIG. 18 ) where a flow direction is changed is almost removed so that the purge gas distributed by the purge unit  6  flows along the outer surface of the second protrusion portion  8  and then flows along the upper surface of the center plate  72 , and thus, the purge gas distributed by the purge unit  6  may easily penetrate into the substrates S supported by the supporting parts  2  by using a distributive force distributed to the second protrusion portion  8 . Accordingly, in the comparative example, a deviation of a processing rate, such as a deposition rate or an etching rate, occurs partially in the substrates S due to the purge gas distributed by the purge unit  6 . 
     On the other hand, in an embodiment where the first distance FD is implemented to be equal to or longer than the second distance SD, a distance by which the center plate  72  protrudes from the second protrusion portion  8  to the outside is implemented to be equal to a distance by which the center plate  72  is spaced apart from the supporting parts  2 . In an embodiment, the distance by which the center plate  72  protrudes from the second protrusion portion  8  to the outside is implemented to be longer than the distance by which the center plate  72  is spaced apart from the supporting parts  2 . Therefore, in an embodiment, an elbow period TD where a flow direction is changed is more clearly formed than the comparative example so that the purge gas distributed by the purge unit  6  flows along the outer surface of the second protrusion portion  8  and then flows along the upper surface of the center plate  72 . Therefore, a distributive force with which the purge unit  6  distributes the purge gas to the second protrusion portion  8  is reduced while passing through the elbow period TD, and thus, the purge gas distributed by the purge unit  6  is difficult to penetrate into the substrates S supported by the supporting parts  2 . Accordingly, an embodiment may decrease a degree of deviation of a processing rate, such as a deposition rate or an etching rate, which occurs partially in the substrates S due to the purge gas distributed by the purge unit  6 . In an embodiment, the second protrusion portion  8  may be provided to have a size which is less than that of the center plate  72 , and thus, the first distance FD may be implemented to be equal to or longer than the second distance SD. In this case, a diameter of the second protrusion portion  8  may be implemented to be less than that of the center plate  72 . 
     In a case where the second protrusion portion  8  is provided, an insertion groove  41  (illustrated in  FIG. 17 ) may be formed in the lid  4 . 
     The second protrusion portion  8  may be inserted into the insertion groove  41 . Therefore, the substrate processing apparatus  1  according to the present inventive concept may prevent a separated distance between the supporting parts  2  and the distribution unit  5  from increasing due to a height of the second protrusion portion  8  and may decrease a degree to which a total size increases in a height direction. Also, the substrate processing apparatus  1  according to the present inventive concept may increase a height of the second protrusion portion  8 , and thus, may increase a distance which should increase in order for a process gas distributed by the distribution unit  5  to pass through the second protrusion portion  8 . Therefore, the substrate processing apparatus  1  according to the present inventive concept may more reinforce a preventive force which prevents mixing of different kinds of process gases. The second protrusion portion  8  may be inserted into the insertion groove  41  so that the upper end  80  thereof is disposed at a position which is higher than the lower end  510  of the distribution hole  51 . 
     The purge unit  6  may be disposed in the insertion groove  41 . The purge unit  6  may be coupled to the lid  4  so as to be disposed in the insertion groove  41  in the upward direction UD (the arrow direction) with respect to the second protrusion portion  8 . In this case, the purge unit  6  may distribute the purge gas to the insertion groove  41  in the upward direction UD (the arrow direction) with respect to the second protrusion portion  8 . 
     The insertion groove  41  may be formed in a wholly cylindrical shape, but is not limited thereto and may be formed in an arbitrary shape into which the second protrusion portion  8  is capable of being inserted. 
     In a case where the insertion groove  41  is formed in the lid  4 , the second protrusion portion  8  may be provided to have a size which is less than that of the insertion groove  41 , so as to be spaced apart from an inner wall  42  (illustrated in  FIG. 17 ) of the lid  4  where the insertion groove  41  is provided. Therefore, the purge unit  6  may distribute the purge gas to a region between the inner wall  42  of the lid  4  and the second protrusion portion  8 . That is, a region between the second protrusion portion  8  and the inner wall  42  of the lid  4  may be used as a path through which the purge gas passes. Therefore, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that the purge gas distributed by the purge unit  6  moves to the first protrusion portion  7  through the region between the second protrusion portion  8  and the inner wall  42  of the lid  4 . Therefore, the substrate processing apparatus  1  according to the present inventive concept may exhaust a process gas remaining in the center region CA by using the purge gas which has moved to the first protrusion portion  7 . Also, the purge gas distributed by the purge unit  6  downward move to the first protrusion portion  7 , and thus, the substrate processing apparatus  1  according to the present inventive concept may prevent the process gas distributed by the distribution unit  5  from being raised along the second protrusion portion  8 . 
     In a case where the insertion groove  41  is formed in the lid  4 , the second protrusion portion  8  may include an induction groove  81  (illustrated in  FIG. 17 ). 
     The induction groove  81  induces a turbulent flow of the purge gas to be formed in the insertion groove  41 . The turbulent flow of the purge gas formed in the insertion groove  41  by the induction groove  81  may prevent the process gas from flowing into the region between the inner wall  42  of the lid  4  and the second protrusion portion  8 . Accordingly, the substrate processing apparatus  1  according to the present inventive concept may more increase a preventive force which prevents mixing of different process gases by using the induction groove  81 . 
     The induction groove  81  may be implemented as a groove which is formed to have a certain depth in the outer surface of the second protrusion portion  8 . The induction groove  81  may be formed in a corner portion located in the upper end  80  of the second protrusion portion  8 . A distance by which a portion, where the induction groove  81  is provided, is spaced apart from the inner wall  42  of the lid  4  may be implemented to be greater than a distance by which another portion of the second protrusion portion  8  is spaced apart from the inner wall  42  of the lid  4 . 
     Referring to  FIGS. 2 to 18 , the substrate processing apparatus  1  according to the present inventive concept may include a first division mechanism  61  and a second division mechanism  62 . 
     The first division mechanism  61  distributes the purge gas. The first division mechanism  61  may be coupled to the lid  4  so as to be disposed on the disk  3 . The first division mechanism  61  may distribute the purge gas to a first division region DA 1  (illustrated in  FIG. 16 ). The first division region DA 1  may be disposed between the first processing region PA 1  and the second processing region PA 2  along the rotational path. The first division region DA 1  may be disposed in one side of the purge unit  6 . Therefore, the first division mechanism  61  may distribute the purge gas to the first division region DA 1 , and thus, may spatially divide the first processing region PA 1  and the second processing region PA 2  in the one side of the purge unit  6 . Therefore, the first division mechanism  61  may prevent different kinds of process gases from being mixed through the first division region DA 1 . 
     The second division mechanism  62  distributes the purge gas. The second division mechanism  62  may be coupled to the lid  4  so as to be disposed on the disk  3 . The second division mechanism  62  may distribute the purge gas to a second division region DA 2  (illustrated in  FIG. 16 ). The second division region DA 2  may be disposed between the first processing region PA 1  and the second processing region PA 2  along the rotational path. The second division region DA 2  may be disposed in the other side of the purge unit  6 . Therefore, the second division mechanism  62  may distribute the purge gas to the second division region DA 2 , and thus, may spatially divide the first processing region PA 1  and the second processing region PA 2  in the other side of the purge unit  6 . Therefore, the second division mechanism  62  may prevent different kinds of process gases from being mixed through the second division region DA 2 . 
     Referring to  FIGS. 2 to 19 , a second protrusion portion  8  according to a modified embodiment of the present inventive concept may include a dispersion groove  82  (illustrated in  FIG. 19 ) 
     The dispersion groove  82  disperses the purge gas distributed by the purge unit  6 . The dispersion groove  82  may be provided in the upper surface  83  (illustrated in  FIG. 19 ) of the second protrusion portion  8 . The upper surface  83  of the second protrusion portion  8  is a surface of the second protrusion portion  8  which is disposed to face the purge unit  6 . Therefore, the dispersion groove  82  may increase a distance by which the upper surface  83  of the second protrusion portion  8  is spaced apart from the purge unit  6 . Accordingly, by using the dispersion groove  82 , the substrate processing apparatus  1  according to the present inventive concept may prevent the purge gas distributed by the purge unit  6  from flowing backward to the purge unit  6  when the purge gas distributed by the purge unit  6  is blocked by the upper surface  83  of the second protrusion portion  8 . This will be described below in detail. 
     First, when the upper surface  83  of the second protrusion portion  8  is provided as a flat surface without the dispersion groove  82 , the distance by which the upper surface  83  of the second protrusion portion  8  is spaced apart from the purge unit  6  may be implemented to be narrow, and thus, the purge gas distributed by the purge unit  6  may stay without being dispersed to the outside because the purge gas is blocked by the upper surface  83  of the second protrusion portion  8 . In this state, when the purge unit  6  continuously distributes the purge gas, there is a risk where the purge gas is blocked by the upper surface  83  of the second protrusion portion  8  and flows backward to the purge unit  6 . 
     Next, when the dispersion groove  82  is formed in the upper surface  83  of the second protrusion portion  8 , the dispersion groove  82  may increase the distance by which the upper surface  83  of the second protrusion portion  8  is spaced apart from the purge unit  6 . Therefore, the second protrusion portion  8  is implemented to have a sufficient space which enables the purge gas distributed by the purge unit  6  to be smoothly dispersed through the dispersion groove  82 . Therefore, by using the dispersion groove  82 , the substrate processing apparatus  1  according to the present inventive concept may prevent the purge gas distributed by the purge unit  6  from flowing backward to the purge unit  6 , and thus, may reinforce a preventive force which prevents mixing of different kinds of reactant gases and an exhaustive force which exhausts a process gas. 
     Due to the dispersion groove  82 , the second protrusion portion  8  may be implemented so that the distance by which the upper surface  83  of the second protrusion portion  8  is spaced apart from the purge unit  6  without any change in height of a prevention surface  84  (illustrated in  FIG. 19 ). The prevention surface  84  is a surface of the second protrusion portion  8  facing the processing region PA, for decreasing a size of an empty space in the center region CA. When the second protrusion portion  8  is provided in a cylindrical shape, the prevention surface  84  may correspond to a side surface of the second protrusion portion  8 . 
     The dispersion groove  82  may be formed so that a size is reduced as the dispersion groove  82  extends in a downward direction DD (an arrow direction). The downward direction DD (the arrow direction) is a direction from the purge unit  6  to the second protrusion portion  8 . Therefore, the dispersion groove  82  may be provided so that a portion corresponding to a purge gas distribution region to which the purge unit  6  distributes the purge gas is formed to have a deeper depth and a depth become shallower as the dispersion groove  82  extends to the outside toward the prevention surface  84 . Therefore, the dispersion groove  82  may further increase the distance, by which the upper surface  83  of the second protrusion portion  8  is spaced apart from the purge unit  6 , in the purge gas distribution region. When the second protrusion portion  8  is provided in a cylindrical shape, the purge gas distribution region may be provided to have a diameter which is less than that of the second protrusion portion  8 . 
     The dispersion groove  82  may be formed so that a size is reduced as the dispersion groove  82  extends in the downward direction DD (the arrow direction), and thus, the upper surface  83  of the second protrusion portion  8  may be provided to be inclined so that a height thereof is lowered as the upper surface  83  extends from the prevention surface  84  to an inner portion. That is, the upper surface  83  of the second protrusion portion  8  may be provided to be inclined so that a height thereof is lowered as the upper surface  83  extends to the outside toward the prevention surface  84 . Accordingly, the upper surface  83  of the second protrusion portion  8  may induce the purge gas distributed by the purge unit  6  to flow to the outside toward the prevention surface  84 . 
     The dispersion groove  82  may be provided in a circular cone shape where a size is reduced as the dispersion groove  82  extends in the downward direction DD (the arrow direction). Therefore, the dispersion groove  82  may be formed to have a maximum depth in a portion corresponding to the purge gas distribution region. Therefore, the substrate processing apparatus  1  according to the present inventive concept may be implemented so that a widest space is secured in a portion on which the purge gas distributed by the purge unit  6  concentrates through the dispersion groove  82 . In this case, the dispersion groove  82  may be provided to have a maximum depth on the rotational shaft  3   b  of the disk  3 . The dispersion groove  82  may be provided so that a depth becomes shallower as the dispersion groove  82  extends from a portion having a maximum depth to the outside toward the prevention surface  84 . 
     The present inventive concept described above are not limited to the above-described embodiments and the accompanying drawings and those skilled in the art will clearly appreciate that various modifications, deformations, and substitutions are possible without departing from the scope and spirit of the invention.