Patent Publication Number: US-2023136312-A1

Title: Inductively coupled plasma reactor and wire structure for antenna coil of inductively coupled plasma reactor

Description:
TECHNICAL FIELD 
     present invention relates to a technology for processing exhaust gas discharged from a process chamber of a semiconductor manufacturing facility using plasma, and more particularly, to an inductively coupled plasma reactor for processing exhaust gas discharged from a process chamber of a semiconductor manufacturing facility using inductively coupled plasma. 
     BACKGROUND ART 
     Semiconductor devices are manufactured by repeatedly performing processes such as photolithography, etching, diffusion, and metal deposition on a wafer in a process chamber. During a semiconductor manufacturing process, various process gases are used, and after the process is completed, a residual gas in the process chamber contains various harmful components such as PFCs. The residual gas in the process chamber is discharged through an exhaust line by a vacuum pump after the process is completed, and the exhaust gas is purified by an exhaust gas processing device so that harmful components are not discharged as they are. 
     Recently, a technique of decomposing and processing harmful components using a plasma reaction has been widely used. As a prior art related to the present invention, Korean Patent Laid-open Publication No. 2019-19651 discloses a plasma chamber for processing exhaust gas using inductively coupled plasma. In inductively coupled plasma, when radio frequency power is applied to the antenna coil, a magnetic field is induced by a time-varying current flowing through the antenna coil, thereby generating plasma by an electric field generated inside the chamber. In general, a plasma reactor for inductively coupled plasma includes a chamber providing a space for generating plasma, a ferrite core coupled to surround the chamber, an antenna coil wound around the ferrite core, and an igniter for initial plasma ignition. 
     Because the current flowing through the antenna coil is proportional to the cross-sectional area of a wire forming the antenna coil, in order to apply a high voltage, a thick wire needs to be used to form the antenna coil. However, when the thick wire is used, it is difficult to manufacture a plasma reactor. Although the antenna coil is sometimes formed by using a copper plate instead of the thick wire, workability is lowered even in the case of the copper plate because the copper plate is easily damaged and not easy to bend. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     The present invention provides an inductively coupled plasma reactor and a wire structure for an antenna coil of an inductively coupled plasma reactor. 
     Technical Solution 
     According to an aspect of the present invention, there is provided an inductively coupled plasma reactor including a reaction chamber configured to provide a plasma reaction space, a ferrite core arranged to surround the plasma reaction space, and an antenna coil formed by winding a strip-shaped wire structure on the ferrite core, wherein the wire structure includes a plurality of electrically conductive wires and a covering made of a flexible material and configured to surround the plurality of electrically conductive wires. 
     According to another aspect of the present invention, there is provided a wire structure for an antenna coil of an inductively coupled plasma reactor so as to form the antenna coil by winding the antenna coil on a ferrite core in the inductively coupled plasma reactor including a reaction chamber configured to provide a plasma reaction space and a ferrite core arranged to surround the plasma reaction space, the wire structure including a plurality of electrically conductive wires arranged in parallel, and a strip-shaped covering made of a flexible material and configured to surround the plurality of electrically conductive wires. 
     Effects of the Invention 
     According to the present invention, all the objectives of the present invention described above can be achieved. Specifically, in an inductively coupled plasma reactor including a reaction chamber providing a plasma reaction space and a ferrite core disposed to surround the plasma reaction space, a thin strip-shaped wire structure including a plurality of electrically conductive wires and a covering formed of a flexible material for surrounding the plurality of electrically conductive wire is wound around the ferrite core so as to form an antenna coil, so that the antenna coil capable of applying a high voltage can be easily formed with improved workability. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view illustrating an inductively coupled plasma reactor according to an embodiment of the present invention. 
         FIG.  2    is a longitudinal cross-sectional view of the inductively coupled plasma reactor shown in  FIG.  1   . 
         FIG.  3    is an exploded perspective view illustrating the inductively coupled plasma reactor shown in  FIG.  1   . 
         FIG.  4    is a view illustrating a cross-sectional structure of a wire structure for an antenna coil of an inductively coupled plasma reactor according to an embodiment of the present invention. 
         FIG.  5    is a view illustrating a process of manufacturing the wire structure shown in  FIG.  4   . 
     
    
    
     MODE OF THE INVENTION 
     Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the drawings. 
     An inductively coupled plasma reactor according to an embodiment of the present invention is shown in a perspective view in  FIG.  1   , in a longitudinal sectional view in  FIG.  2   , and in an exploded perspective view in  FIG.  3   . Referring to  FIGS.  1 ,  2 , and  3   , an inductively coupled plasma reactor  100  according to an embodiment of the present invention includes a reaction chamber  150 , a ferrite core  110  disposed to surround the reaction chamber  150 , and an antenna coil  160  formed by winding a wire structure according to the present invention around the ferrite core  110 . In the present embodiment, the inductively coupled plasma reactor  100  is described as being installed in an exhaust pipe through which residual gas generated from a process chamber in a semiconductor manufacturing facility is discharged so that the exhaust gas flowing along the exhaust pipe is processed by using inductively coupled plasma. The present invention does not limit the use and installation location of the inductively coupled plasma reactor  100  in this way. The inductively coupled plasma reactor  100  is operated by receiving appropriate alternating current (AC) power from a power source  190 . 
     The reaction chamber  150  is a chamber having a toroidal shape, and a plasma reaction space  153  in which a plasma reaction to a gas to be processed occurs, is formed in the reaction chamber  150 . The reaction chamber  150  is provided with a gas inlet  154   a  that communicates with the plasma reaction space  153  and introduces the gas to be processed into the plasma reaction space  153 , and a gas outlet  154   b  through which the plasma-processed gas in the plasma reaction space  153  is discharged to the outside. The reaction chamber  150  includes a first base portion  151   a  that is in communication with the gas inlet  154   a,  a second base portion  151   b  that is in communication with the gas outlet  154   b,  and first and second connection pipes  156  and  159  that connect the two base portions  151   a  and  151   b.    
     The first base portion  151   a  provides a first internal space  152   a  therein, and the gas inlet  154   a  which is in communication with the first internal space  152   a  and through which the gas to be processed is introduced, is formed in the first base portion  151   a . Although not shown, an igniter is inserted and installed in the first base portion  151   a.    
     The first internal space  152   a  communicates with the gas inlet  154   a,  the first connection passage  155 , and the second connection passage  157 . In the drawing, the gas inlet  154   a  is in communication with the upper part of the first internal space  152   a,  and the first and second connection passages  155  and  157  are in communication with the lower part of the first internal space  152   a.  The gas to be processed flowing through the gas inlet  154   a  flows through the first internal space  152   a  to the first connection passage  155  and the second connection passage  157 . 
     The second base portion  151   b  is spaced apart from the first base portion  151   a , provides a second internal space  152   b  therein, and the gas outlet  154   b  which is in communication with second internal space  152   b  and through which the gas is discharged, is formed in the second base portion  151   b.  Although not shown, an igniter is inserted and installed in the second base portion  151   b.  The second base portion  151   b  is connected to the first base portion  151   a  by the first connection pipe  156  and the second connection pipe  159 . 
     The second internal space  152   b  is spaced apart from the first internal space  152   a  and communicates with the gas outlet  154   b,  the first connection passage  155  and the second connection passage  157 . In the drawing, the second internal space  152   b  is located below the first internal space  152   a,  the gas outlet  154   b  communicates with the lower part of the second internal space  152   b,  and the first and second connection passages  155  and  157  communicate with the upper part of the second internal space  152   b.  The gas flowing along the first and second connection passages  155  and  157  is discharged to the outside through the gas outlet  154   b  through the second internal space  152   b.    
     The first connection pipe  156  and the second connection pipe  159  are arranged in parallel to connect the first base portion  151   a  and the second base portion  151   b . The first connection passage  155  through which the first internal space  152   a  of the first base portion  151   a  and the second internal space  152   b  of the second base portion  151   b  to communicate with each other, is formed inside the first connection pipe  156 , and the second connection passage  157  through which the second internal space  152   b  of the first base portion  151   a  and the second internal space  152   b  of the second base portion  151   b  to communicate with each other, is formed inside the second connection pipe  159 . The first connection pipe  156  and the second connection pipe  159  are spaced apart from each other, and a slot  121  is formed between the first connection pipe  156  and the second connection pipe  159 . 
     The first internal space  151   a,  the second internal space  151   b,  the first connection passage  155  and the second connection passage  157 , which are connected to each other, form the plasma reaction space  153 . Plasma is generated in the plasma reaction space  153  along an annular discharge loop R as shown by a broken line in  FIG.  2   . 
     In the present embodiment, it will be described that the reaction chamber  150  is configured by combining a first chamber unit  150   a  and a second chamber unit  150   b  by an appropriate coupling unit. 
     The first chamber unit  150   a  includes the first base portion  151   a,  and a first A-extension pipe  155   a  and a second A-extension pipe  157   a  extending from the first base portion  151   a.    
     The first base portion  151   a  provides the first internal space  152   a  therein, and the first base portion  151   a  which communicates with the first internal space  152   a  and the gas inlet  154   a  and through which the gas to be processed is introduced, is formed in the first base portion  151   a.  Although not shown, an igniter is inserted and installed in the first base portion  151   a.    
     The first A-extension pipe  155   a  and the second A-extension pipe  157   a  communicate with a first internal space  162   a  of the first base portion  151   a,  and the end of the first A-extension pipe  165   a  and the end of the second A-extension pipe  167   a  are open. The open end of the first A- extension pipe  165   a  and the open end of the second A-extension pipe  167   a  are connected to the second chamber unit  150   a.    
     The second chamber unit  150   b  has substantially the same structure as the first chamber unit  150   a  and includes a second base portion  151   b  and a first B-extension pipe  155   b  and a second B-extension pipe  157   b,  which extend from the second base portion  151   b.    
     The second base portion  151   b  provides a second internal space  152   b  therein, and the second base portion  151   b  which communicates with the second internal space  152   b  and through which the gas to be processed is introduced, is formed in the second base portion  151   b.  Although not shown, an igniter is inserted and installed in the second base portion  151   b.    
     The first B-extension pipe  155   b  and the second B-extension pipe  157   b  are formed to extend parallel to each other from the second base portion  151   b.  The first B-extension pipe  155   b  and the second B-extension pipe  157   b  communicate with the second inner space  152   b  of the second base portion  151   b,  and the end of the first B-extension pipe  155   b  and the end of the second B-extension pipe  157   b  are open. The first A-extension pipe  155   a  and the second B-extension pipe  155   b  are connected to each other to form the first connection pipe  156 , and the second A-extension pipe  157   a  and the second B-extension pipe  157   b  are connected to each other to form the second connection portion  159 . Although not shown, a direct current (DC) breaker is located between the end of the first A-extension pipe  155   a  and the end of the first B-extension pipe  155   b  and between the end of the second A-extension pipe  157   a  and the end of the second B-extension pipe  157   b.    
     The ferrite core  110  includes a border wall  111  and a partition wall  115  positioned inside the border wall  111 . The ferrite core  110  is disposed to surround a part of the plasma reaction space  153  formed in the reaction chamber  150 . The ferrite core  110  is formed with a first passage portion  117   a  and a second passage portion  117   b  extending in the vertical direction in the drawing. The first passage portion  117   a  and the second passage portion  117   b  pass through the ferrite core  110  so that both ends of the upper and lower portions thereof are opened, and the side surfaces thereof are blocked. In the present embodiment, the ferrite core  110  will be described as being a ferrite core commonly used in an inductively coupled plasma device. 
     The border wall  111  includes first and second long wall portions  112   a  and  112   b , which are formed to have a rectangular circumference and face each other, and first and second short wall portions  113   a  and  113   b,  which have smaller widths than those of the first and second long wall portions  112   a  and  112   b.  Each of the first short wall portion  113   a  and the second short wall portion  113   b  connects opposite ends of the first long wall portion  112   a  and the second long wall portion  112   b  in a width direction so that the first long wall portion  112   a,  the first short wall portion  113   a,  the second long wall portion  113   b,  and the second short wall portion  113   b  are continuously connected along the circumferential direction of the border wall  111 . 
     The partition wall  115  extends in a straight line between the two opposite long wall portions  112   a  and  112   b  of the border wall  111 . Both ends of the partition wall  115  are connected to a middle portion in the width direction of each of the two long wall portions  112   a  and  112   b.  By the partition wall  115 , the inner region of the border wall  111  is divided into the first passage portion  117   a  and the second passage portion  117   b  having a rectangular shape, respectively. The wire structure according to the present invention is wound around the partition wall  115  to form the antenna coil  160 . 
     The ferrite core  110  is located between the first base portion  151   a  and the second base portion  151   b  of the reaction chamber  150 , and the first connection pipe  156  of the reaction chamber  150  passes through the first passage portion  117   a  formed in the ferrite core  110 , and the second connection pipe  159  of the reaction chamber  150  passes through the second passage portion  117   b  formed in the ferrite core  110 . Accordingly, the partition wall  115  of the ferrite core  110  is positioned in the slot  121  formed between the first connection pipe  156  and the second connection pipe  159  of the reaction chamber  150 . 
     The antenna coil  160  is formed by winding the wire structure according to the present invention around the partition wall  115  of the ferrite core  110  and is located in the slot  121  formed between the first connection pipe  156  and the second connection pipe  159  of the reaction chamber  150  together with the partition wall  115  of the ferrite core  110 . 
       FIG.  4    shows a cross-sectional structure of an antenna coil of an inductively coupled plasma reactor according to an embodiment of the present invention. The antenna coil  160  shown in  FIGS.  2  and  3    is formed by winding a wire structure having the configuration as shown in  FIG.  4    around the partition wall  115  of the ferrite core  110 . Referring to  FIG.  4   , a wire structure  160   a  for the antenna coil of the inductively coupled plasma reactor according to an embodiment of the present invention has a shape of a thin strip extending as a whole and includes a plurality of electrically conductive wires arranged in parallel along the length direction and a covering  180  formed of a flexible material and covering the entire plurality of electrically conductive wires  170 . 
     Each of the plurality of electrically conductive wires  170  is disposed to extend along the length direction of the wire structure  160   a  for the antenna coil, and the plurality of electrically conductive wires  170  are arranged to be sequentially parallel to each other along the width direction of the wire structure  160   a  for the antenna coil. AC power by a power source ( 190  in  FIG.  2   ) is applied to the plurality of electrically conductive wires  170 . In the present embodiment, the electrically conductive wire  170  is described as being a copper wire, but the present invention does not limit the material of the electrically conductive wires  170  to copper. In addition, although that six electrically conductive wires  170  are used in the drawing, the present invention does not limit the number of electrically conductive wires  170  to six. 
     The covering  180  is in the form of a thin strip and surrounds the entire plurality of electrically conductive wires  170 . The covering  180  is made of a flexible and electrically insulating material. The covering  180  includes a first covering sheet portion  181  and a second covering sheet portion  182  adhered with a plurality of electrically conductive wires  170  therebetween. In the present embodiment, it will be described that the covering  180  is an adhesive tape coated with an adhesive on one side. In this case, the covering  180  may be manufactured in a manner as shown in  FIG.  5   . Referring to  FIG.  5   , a folding line  185  extending along the length direction of the adhesive tape  180   a  is formed on the adhesive tape  180   a  and generally passing through the center in the width direction. The adhesive tape  180   a  is divided into a first side portion  181   a  and a second side portion  182   a  by the folding line  185 . After a plurality of electrically conductive wires  170  are disposed on the adhesive surface of the first side portion  181   a,  adhered and fixed, the second side portion  182   a  is folded around the folding line  185  so that the first side portion  181   a  and the second side portion  1812   a  are adhered to each other. In  FIG.  5   , the first side portion  181   a  of the adhesive tape  180   a  forms the first covering sheet portion ( 181  of  FIG.  4   ) of the covering ( 180  of  FIG.  4   ), and the second side portion  182   a  of the adhesive tape  180   a  forms the second covering sheet portion ( 182  of  FIG.  4   ) of the covering ( 180  of  FIG.  4   ). In the present embodiment, it will be described that a polyimide tape called Kapton Tape is generally used as the adhesive tape  180   a.    
     In the present embodiment, the first covering sheet portion ( 181  of  FIG.  4   ) and the second covering sheet portion ( 182  of  FIG.  4   ) of the covering ( 180  of  FIG.  4   ) are formed by one adhesive tape ( 180   a  of  FIG.  5   ). However, unlike this, the first covering sheet portion ( 181  of  FIG.  4   ) and the second covering sheet portion ( 182  of  FIG.  4   ) may be formed by separate sheets, and this also falls within the scope of the present invention. In this case, both sheets may be adhesive tapes, but only one may be adhesive tapes. 
     The wire structure  160   a  for the antenna coil of the inductively coupled plasma reactor according to the present invention provides a sufficient cross-sectional area to enable high voltage application by arranging a plurality of electrically conductive wires  170  in parallel, and a plurality of electrically conductive wires  170  are wound around the covering  180  having a strip shape and made of a flexible material so that the convenience of operation is improved. 
     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.