Abstract:
Disclosed is an atmospheric pressure plasma apparatus for enhancing and or controlling the dissociation of a secondary gas by converting a source gas into a plasma state at atmospheric pressure and controlling the interaction between that plasma and the secondary gas using porous metal, and ceramic tubes to create a path having controllable isolation from the region where plasma is generated.

Description:
BACKGROUND OF THE SUBJECT MATTER 
     The present subject matter relates to atmospheric pressure plasma apparatus, and more particularly to an atmospheric pressure plasma apparatus for enhancing dissolvability of a secondary gas by converting a source gas into a plasma state in an atmospheric state and passing a secondary gas through a path isolated from a region where plasma is generated. 
     Plasma is generally defined as a state of matter composed of ions, electrons, radicals, and a variety of neutral species, by an electric field, to be in an electrically neutral state. Such plasma is widely used in numerous applications such as modifying surface properties of materials, etching, coating, sterilization, disinfecting, generating ozone, dyeing, cleaning waste water, cleaning faucet water, air cleaning, and high-gain lamps, and so forth employing ions, electrons, and radicals therein. 
     Plasma is classified into low-pressure plasma (several mm Torr to several Torr) and high-pressure plasma (several Torr to 760 Torr), depending on the pressure created. Low pressure plasma is easily generated, but shows several disadvantages. For example, since vacuum chambers and exhaust apparatus are required to maintain a low state, low plasma suffers from the disadvantage of high expense. In addition, it is difficult to produce low pressure plasma on a large scale by adopting batch type. 
     On the other hand, high-pressure plasma is created in atmospheric pressure (760 Torr). As a result, expensive vacuum systems are not required, and it is possible to produce high-pressure plasma on a large scale by employing continuous process. 
     Meanwhile, when high voltage is applied to two separated electrodes and source gas is supplied therebetween, the source gas becomes ionized and dissolved to generate plasma. 
     In the event that a secondary gas is supplied to a region where the plasma is generated, it collides with particles such as ions, electrons, and radicals, which are formed by dissolving the source gas, so that the molecular combination of the secondary gas becomes disconnected to ionize molecules. Accordingly, the atmospheric pressure plasma apparatus are now applied employing ionized source gas to a broad range of fields, including processing such as modifying surface properties, etching, deposition, nanotube-growth, and so forth. 
     In conventional atmospheric pressure plasma apparatuses, however, the source gas is converted into plasma in a region where plasma is generated between two electrodes. Then, the secondary gas is ionized in the region where plasma is generated, which is to be injected to outside via one of two electrodes. As a result, dissolved secondary gas collides against a path capable of passing one of two electrodes. For this reason, the conventional atmospheric apparatus, however, have the drawback in which the reagent of the dissolved secondary gas is lost. 
     In other words, after the source gas is provided to a region where plasma is created to be dissolved, it is injected to the outside. Thus, there is a disadvantage that the reagent of the secondary gas is dissolved under injection process. 
     SUMMARY OF THE SUBJECT MATTER 
     Accordingly, various embodiments of the present subject matter are configured to overcome the drawback in the prior art and to provide an atmospheric pressure plasma apparatus capable of minimizing the loss of reagent of a secondary gas which is dissolved to be injected into a processing object or a processing region by separately passing through a region in which source gas is converted into a plasma state. 
     Some embodiments according to the present subject matter provide an atmospheric pressure plasma apparatus comprising: a first electrode being porous and having a plurality of first penetrating holes; a second electrode forming an isolating space apart from the first electrode as far as a predetermined distance having second penetrating holes corresponding to the first penetrating holes and a plurality of first connecting holes for connecting the isolating space and an outer region; and a ceramic nozzle penetrating the first and second penetrating holes to be connected to the outer region, wherein a source gas is provided to the isolating space through the first electrode, and wherein a secondary gas passes the isolating space through the ceramic nozzle to the outer region, and wherein a radio frequency power supply is applied to the first and second electrodes to generate plasma in the isolating space from the source gas supplied through the first electrode, and wherein the plasma is injected to the outer region through the first connecting holes, and wherein if the secondary gas passing the isolating space through the ceramic nozzle is injected to the outer region, the plasma and the secondary gas is mixed in the outer region. 
     Additionally, various embodiments of the present subject matter provide an atmospheric pressure plasma apparatus that is configured such that each end of the ceramic nozzle is positioned in each of the mixing grooves. 
     Further, various embodiments of the present subject matter provide an atmospheric pressure plasma apparatus comprising: an atmospheric pressure plasma apparatus comprising a housing having an internal space including a gas supplying part and an apparatus mounting part, wherein a secondary gas chamber is formed in the gas supplying part, and a source gas supplying pipe is formed inside wall of the gas supplying part; a nozzle holder mounted on the apparatus mounting part of the housing and formed in a shape to include a source gas chamber defined by a bottom and sidewalls of the housing, the nozzle holder having an external diameter smaller than an internal diameter of the mounting part to supply a source gas from the source gas supplying pipe to a source-gas guide region of the housing, the nozzle holder including a plurality of third penetrating holes in the bottom thereof, the nozzle holder including at least one source gas supplying hole for connecting the source-gas guide region and the source gas chamber; a subsidiary electrode mounted on the nozzle holder, having the external diameter the same as that of the nozzle holder, and formed in a shape of a disk whose center&#39;s a predetermined region is empty; a disk-shaped first electrode mounted on the subsidiary electrode, including a plurality of first penetrating holes corresponding to the third penetrating holes of the nozzle holder, and formed of porous materials; an electrode insulator formed in a shape having an internal diameter the same as or greater than an external diameter of the subsidiary electrode, mounted on the first electrode with sidewalls of the subsidiary electrode and the first electrode covered, and including a bottom whose center&#39;s predetermined region is empty; a disk-shaped second electrode mounted on the electrode insulator, having the same diameter the same as an external diameter of the electrode insulator, forming a isolating space apart from the first electrode as far as a predetermined distance by the electrode insulator, including a first connecting hole for connecting the isolating space and an outside, and including a second penetrating hole corresponding to the first penetrating hole; a ceramic nozzle included so as to penetrate the third penetrating hole of the nozzle holder, the first penetrating hole of the first electrode, and the second penetrating hole of the second chamber; and a cap exposing a central region of the second electrode and sealing the internal space of the housing by simultaneously covering an edge of the second electrode and a predetermined region of the housing, and wherein a radio frequency power supply is applied to the first and second electrodes to generate plasma in the isolating space from the source gas supplied through the first electrode, and wherein the plasma is injected to the outer region through the first connecting holes, and wherein if the secondary gas passing the isolating space through the ceramic nozzle is injected to the outer region, the plasma and the secondary gas is mixed in the outer region. 
     In some embodiments according to the present subject matter, the ceramic nozzle penetrating the second electrode and the first connecting hole may comprise at least one unit cell covered with at least one second connecting hole on the ceramic nozzle and may be disposed on the second electrode. 
     In further embodiments, a cover is further included. The cover is disposed between the second electrode and the housing, having the external diameter the same as that of the second electrode, including at least one mixing groove, and a second connecting hole for connecting the mixing groove and the outside. At least one connecting hole and at least one ceramic nozzle are connected to provide the secondary gas and plasma to each of the mixing grooves. The secondary gas mixed with the plasma is injected to the outside through second connecting hole. 
     Additionally, embodiments of the present subject matter provide an atmospheric pressure plasma apparatus comprising configured such that each the ends of the ceramic nozzle is positioned in each of the mixing grooves. 
     In other embodiments, an electrode connecting rod is further included. However, when it is included, the electrode connecting rod may be connected to the outside power supply in the bottom of the subsidiary electrode. The electrode connecting rod may be configured to penetrate the nozzle holder which is to be extended to the gas supplying part. 
     In yet other embodiments, a housing insulator is further included. The housing insulator is capable of insulating the housing and the secondary gas on walls corresponding to the gas supplying part of the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the subject matter. The drawings are incorporated herein by reference and constitute a part of this specification. The drawings illustrate example embodiments of the present subject matter and, together with the description, serve to explain principles of the present subject matter. In the drawings: 
         FIG. 1  shows the conception of an atmospheric pressure plasma apparatus in accordance with an embodiment of the present subject matter; 
         FIGS. 2 and 3A  to  3 H are partial cross-sectional perspective views of an atmospheric pressure plasma apparatus in accordance with an embodiment of the present subject matter; 
         FIG. 4  is a drawing for magnifying a region of  FIG. 1 ; 
         FIGS. 5A and 5B  are partial cross-sectional perspective views of an atmospheric pressure plasma apparatus in accordance with another embodiment of the present subject matter; and 
         FIG. 6  shows the flow of source gas of the atmospheric pressure plasma apparatus according to first embodiment of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the present subject matter will be described below in more detail with reference to the accompanying drawings. The present subject matter may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. 
       FIG. 1  shows the conception of an atmospheric pressure plasma apparatus in accordance with an embodiment of the present subject matter. 
     Referring to  FIG. 1 , the atmospheric pressure plasma apparatus  100  according to an embodiment of the present subject matter includes a first electrode  110 , a second electrode  120 , and a ceramic nozzle  130 . Also, a cover may be further included on the second electrode  120 . The first electrode  110  includes a plurality of first penetrating holes and is made of porous materials in which source gas is easily passed, such as, for example, hydrogen, helium. In this case, the first penetrating hole  112  has a predetermined diameter enough for a ceramic nozzle to be penetrated and arranged regularly. 
     The second electrode  120  includes a plurality of second penetrating holes at a position corresponding to the first penetrating hole  112  of the first electrode  110 . The ceramic nozzle  130  penetrates the first and second penetrating holes  110  and  120 . The ceramic nozzle  130  will be more fully described hereinafter. 
     As shown, the first and second electrodes  110  and  120  are isolated at predetermined distance to such that an isolating space  150  is formed. The isolating space  150 , which is not shown in  FIG. 1  in detail, means a space isolated by the housing together with the first and second electrodes  110  and  120 . According to one embodiment of the present subject matter, plasma is generated in the isolating space  150 . Thus, the isolating space  150  means a plasma generating region. 
     The second electrode  120  includes a plurality of first connecting holes  124 . The first connecting hole  124  performs a function as a path to connect the isolating space  150  to the outside as well as to inject plasma generated in the isolating space  150  to the outside. 
     The ceramic nozzle  130  penetrates the first and second electrodes  110  and  120  to be formed. That is, the ceramic nozzle  130  is formed by penetrating the first and second electrodes  110  and  120  via the first penetrating hole  112  of the first electrode  110  and the second penetrating hole  122  of the second electrode  120 . As shown in  FIG. 1 , one end of the ceramic nozzle  130  is formed to be capable of supplying secondary gas, and the other end thereof is protruded from the second electrode  120  at a predetermined length to inject a primary gas. In this case, the ceramic nozzle  130  crosses over the isolating space  150 , that is, the plasma generating region. The reason for this is that the secondary gas is provided through the ceramic nozzle  130  with isolating plasma in the plasma generating region. 
     The cover  140  may be disposed on the second electrode  120 . The cover  140  performs a function to form mixed gas by mixing plasma injected through the first connecting hole  124  and the secondary gas injected through the ceramic nozzle  130 , and then injects the mixed gas. In this case, the cover  140  includes at least one mixing groove  142  (only one is shown in  FIG. 1 ) on a surface contact therewith. The mixing groove  142  conformally mixes the plasma injected from the first connecting hole  124  and the secondary gas injected from the ceramic nozzle  130 , and then injects the mixture to the outside. That is, each of the ends of the ceramic nozzle  130  is positioned in each of the mixing grooves  142 . 
     The operation of the atmospheric pressure plasma apparatus  100  in accordance with an embodiment of the present subject matter will be described hereinafter. 
     A power supply  160  is connected to the first and second electrodes  110  and  120 . In this case, a source gas  170  is supplied to the atmospheric pressure plasma apparatus  100 . The source gas  170  penetrates the first electrode  110  to be supplied to the isolating space  150  between the first and second electrodes  110  and  120 . The first electrode  110  is made of porous materials. The source gas  150  is phase-changed into plasma  175  by the power supply, which is applied to the first and second electrodes  110  and  120  at the one and the other end of the isolating space  150 . 
     The plasma  175  is injected to the outside through the first connecting hole  124  of the second electrode  120 . 
     A secondary gas  180  penetrates the first electrode  110 , the isolating space  150 , and the second electrode  120  through the ceramic nozzle  130  to the outside in a space isolated from the source gas  170 . 
     In the event that the cover  140  is disposed on the second electrode  120 , the plasma  175  injected through the first connecting hole  124 , and the secondary gas  180  injected from the ceramic nozzle  130 , are conformally mixed and then injected to the outside as the mixed gas  190  through the second connecting hole  144 , which is arranged regularly. 
     According to an embodiment of the atmospheric pressure plasma apparatus  100 , the source gas  170  passes the first electrode  110  to be supplied to the isolating space  150 . The source gas  170  is phase-changed into plasma, and then conformally injected to the outside through the first connecting hole  124  of the second electrode  120 . The secondary gas  180  passes the isolating space  150  through the ceramic nozzle  130 , isolating the plasma generated in the plasma generating region. Then, the secondary gas  180  is injected through the ceramic nozzle  130  which is protruded at a predetermined length from the second electrode  120  and mixed with the plasma injected through the first connecting hole  124  to be conformally dissolved. As a result, the reagent of the secondary gas  180  is improved. 
     At this time, it does not mean that the secondary gas  180  is dissolved in the plasma generating region to be injected to the outside, but that the secondary gas  180  is reacted with the plasma in the outside to be dissolved, so that the movable course of the dissolved secondary gas  180  becomes shortened, thereby minimizing the loss of reagent of the dissolved secondary gas  180 . 
     In the atmospheric pressure plasma apparatus  100  in accordance with the present subject matter, the first connecting hole  124  and the ceramic nozzle  130  are conformally arranged on the second electrode  120 , thereby generating conformal plasma in the light of space. Also, the secondary gas  180  dissolved by the plasma is conformally generated, thereby improving the dissolvability of the secondary gas  180 . 
     As mentioned above, such atmospheric pressure plasma apparatus  100  may be used in numerous applications such as modifying surface properties of materials, etching, coating, sterilization, disinfecting, generating ozone, dyeing, cleaning waste water, cleaning faucet water, air cleaning, and high-gain lamps, and nanotube growing. 
     EXAMPLE 1 
       FIGS. 2 and 3A  to  3 H are partial cross-sectional perspective views of an atmospheric pressure plasma apparatus in accordance with a first embodiment of the present subject matter.  FIGS. 3A to 3H  show each of the parts of  FIG. 2  in detail. 
     Referring to  FIGS. 2 and 3A  to  3 H, an atmospheric pressure plasma apparatus  100  according to the first embodiment of the present subject matter comprises a housing  210 , a nozzle holder  220 , a subsidiary electrode  230 , a first electrode  240 , an electrode insulator  250 , a second electrode  260 , and a cap  280 . The atmospheric pressure plasma apparatus  100  further includes a cover  270  between the second electrode  260  and the cap  280 . 
     Referring to  FIGS. 2 and 3A , the housing  210  forms a body of the atmospheric pressure plasma apparatus  100  together with the cap  280  and protects the inside of the atmospheric pressure plasma apparatus  100 . 
     The housing  210  is classified into a gas supplying part  210   a  and an apparatus mounting part  210   b . An internal space inside the housing  210  equivalent to the gas supplying part  210   a  includes a secondary gas chamber  211  for supplying secondary gas to a ceramic nozzle, which will be described hereinafter. On inner sidewalls of the secondary gas chamber  211 , a secondary gas  201  may fill up the secondary gas chamber  211  and a housing insulator  212  for insulating the housing  210  may be provided. 
     A source-gas supplying pipe  213  for supplying a source gas  202  is disposed on inner sidewalls of the gas supplying part  210   a . As shown, the thickness of inner sidewalls of the gas supplying part  210   a  and the apparatus mounting part  210   b  is different. That is, the thickness of the gas supplying part  210   a  is thicker than that of the apparatus mounting part  210   b , so that a nozzle holder  220  can be mounted on the apparatus mounting part  210   b.    
     At least two O-ring grooves may be included in the housing  210  in order to insert an O-ring. As shown, according to a first embodiment, a first O-ring groove  214 , a second O-ring groove  215 , and a third O-ring groove  216 . 
     The first O-ring groove  214  performs a function to insert an O-ring for closing a space between the nozzle holder  220  and the housing  210 . In addition, it is possible to prevent the secondary gas  210  filled in the secondary gas chamber  211  from being let out. 
     The second and third O-ring grooves  215  and  216  perform a function to insert an O-ring for closing a space between the cap  280  and the housing  210 . In addition, it is possible to prevent internal gas or external gas from being let our or into the housing  210 . 
     Referring to  FIGS. 2 and 3B , the nozzle holder  220  is mounted on the apparatus mounting part  210   b  of the housing  210 . The nozzle holder  220  includes a bottom  221  and sidewalls  222  thereof to be formed in a chalet shape. An external diameter of the nozzle holder  220  is smaller than an internal diameter of the apparatus mounting part  210   b , so that a source-gas guide region  223  is defined between the sidewalls of the nozzle holder  220  and the housing  210 . A secondary gas chamber  211  is defined by the gas supplying part  210   a  of the housing  210  and the bottom  221  of the nozzle holder  220  due to the mounting of the nozzle holder  220 . 
     A plurality of third penetrating holes  224  are included on the bottom  221  of the nozzle holder  220 . The bottom  221  includes an electrode-bar penetrating hole  225  for an electrode bar that is extended from a subsidiary electrode  230 , which will be described. In  FIG. 3 , one electrode-bar penetrating hole  225  is shown, but several electrode-bar penetrating holes may be included. 
     At least one source-gas supplying hole  226  is disposed on the sidewalls  222  of the nozzle holder  220 . The source-gas supplying hole  226  connects the source-gas guide region  223  and a source-gas chamber  225 . Resultantly, a source gas  202  via a source-gas supplying pipe  213  is conformally supplied to the source-gas chamber  225 . 
     The source-gas chamber  225  is defined by a subsidiary electrode  230 , a first electrode  240 , and the nozzle holder  220 . 
     It is preferable that the nozzle holder  220  is formed of insulating material such as Teflon. The reason for this is to insulate the subsidiary electrode  230  and the first electrode  240 , which are mounted on the nozzle holder  220 . 
     Referring to  FIGS. 2 and 3C , the subsidiary electrode  230  is mounted on the nozzle holder  220  and has the same external diameter as that of the nozzle holder  220 . 
     Preferably, the subsidiary electrode  230  is formed in a shape of a disk whose center&#39;s a predetermined region is empty. In this case, the predetermined region is equivalent to the third penetrating holes  22  included on the bottom  221  of the nozzle holder  220 . 
     At least one electrode bar  231  is included on a bottom plate of the subsidiary electrode  230 . The electrode bar  231  penetrates the electrode-bar penetrating hole  225  on the bottom  221  of the nozzle holder  220  to be extended. 
     The subsidiary electrode  230  conformally supplies power supply to a first electrode  240  as a whole. 
     Referring to  FIGS. 2 and 3D , the first electrode  240  is mounted on the subsidiary electrode  230 . A source-gas chamber  242  is defined by the first electrode  240  and the nozzle holder  220 . The source-gas chamber  242  is filled up with the source gas  202  that is supplied through the source-gas supplying pipe  213 , the source-gas guide region  223 , and the source-gas supplying hole  226 . 
     The external diameter of the first electrode  240  is the same as that of the subsidiary electrode  230  and is formed in a shape of disk. 
     The first electrode  240  includes a plurality of first penetrating holes  241  at a position corresponding to the third penetrating hole  224  of the nozzle holder  220 . 
     The first electrode  240  is made of porous material, so that the source gas  202  filled in the source-gas chamber  242  is easily passed. The source gas  202  passing through the source-gas chamber  242  is supplied to the first electrode  240  and an isolating space  251  defined by an electrode insulator  250  and the second electrode  251 . The isolating space  251  is referred to as a “plasma generating region” because the source gas  202  is phase-changed into a plasma state. 
     Accordingly, due to the first electrode  240  formed of porous material, the source gas  202  is conformally supplied to the isolating space  251 , thereby generating conformal plasma. 
     Referring to  FIGS. 2 and 3E , an internal diameter of the electrode insulator  250  is the same as or greater than an external diameter of the subsidiary electrode  230  and the first electrode  240  and formed in a chalet shape. 
     Unlike the nozzle holder  220 , the electrode insulator  250  is formed in a reverse-chalet shape of the nozzle holder  220  and is mounted on the first electrode  240  with covering the sidewalls of the subsidiary electrode  230  and the first electrode  240 . 
     Similar to the subsidiary electrode  220 , the electrode insulator  250  has an empty space in a predetermined region thereof. In this case, the predetermined region corresponds to the third penetrating hole  224  on the bottom  221  of the nozzle holder  220  and the first penetrating holes  241  of the first electrode  241 . 
     Since the electrode insulator  250  insulates the first electrode  240  and a second electrode  250 , it is preferable that it is made of insulating materials such as Teflon. 
     The thickness of a region equivalent to the bottom of the electrode insulator  250  defines an isolated distance, that is, a space between the first and second electrodes  240  and  260 , of an isolating space  251 . 
     Referring to  FIGS. 2 and 3F , the second electrode  260  is mounted on the electrode insulator  250 . 
     The external diameter of the second electrode  260  is the same as that of the electrode insulator  250  and preferably formed in a disk shape. 
     The second electrode  260  includes the isolating space  251  apart from the first electrode as far as a predetermined distance. The isolating space  251  is isolated by the electrode insulator  250 . As mentioned previously, the isolating space  251  is isolated corresponding to the thickness of the region equivalent to the bottom of the electrode insulator  250 . 
     The isolating space  251  is referred to as a “plasma generating region” because the source gas  202  supplied via the first electrode  240  is phase-changed into a plasma state. 
     The second electrode  260  includes a plurality of second penetrating holes  261  at a position corresponding to the first and third penetrating holes  241  and  224  and the first connecting hole  262  for connecting the isolating space and the outside. 
     The first connecting hole  262  performs a function as a path for injecting plasma generated from the isolating space  251  to the outside. 
     The second electrode  260  a plurality of second penetrating holes  261  and first connecting holes  262 . It is preferable that the first connecting holes  261  enclose the second penetrating holes  261 .  FIG. 3F  show that four first connecting holes  261  enclose the second penetrating holes  261 . 
     As shown in  FIG. 4 , one end of the atmospheric pressure plasma apparatus  200  is located at the secondary gas chamber  211 , and the other end of that is protruded from the second electrode  260  toward the outside as much as a predetermined length. As a result, the secondary gas  201  supplied from the secondary gas chamber  211  is connected to the outside. At this time, the ceramic nozzle  290  penetrates the third penetrating hole  224 , the first penetrating hole  241 , and the second penetrating hole  261  sequentially. 
     Accordingly, unit cells are formed by at least four first connecting holes  262  at a center of the ceramic nozzle  290  on the second electrode  260 . The unit cells are arranged on the second electrode  260  regularly. Depending on these unit cells, the secondary gas  210  injected from the ceramic nozzle  290  is conformally mixed with the plasma injected from the first connecting hole  262 . 
     Referring to  FIGS. 2 and 3G , the cover  270  may be mounted on the second electrode  260 . In this case, the cover  270  may be omitted and included on occasion demands. The cover  270  has the same external diameter as the external diameter of the second electrode  260 . 
     Additionally, the cover  270  includes at least one mixing groove  271  (See  FIG. 4 ) on a surface contact with the second electrode  260 . The mixing groove  271  includes at least one second connecting hole  272  for connecting the mixing groove  271  and the outside. That is, each of ends of the ceramic nozzle  290  is positioned in each of the mixing grooves  271 . 
     The mixing groove  271  means a region in which the secondary gas injected form the ceramic nozzle  290  and the plasma injected from the first connecting hole  262  is mixed to form a mixed gas on the second electrode  260 . Thus, the mixed gas, in other words, the secondary gas  201  mixed with the plasma is injected through the second connecting hole  272  to the outside. 
     Referring to  FIGS. 2 and 3H , the cap  280  fixes as well as closes several apparatus mounted on the apparatus mounting part  210   b  of the housing  210  at the same time. 
     The cap  280  may be classified into a bottom  281  and sidewalls  282 . A region corresponding to the second electrode  260  or the second penetrating hole  261  of the cover  270 , the first connecting hole  262 , and the second connecting hole  272  of the bottom  28  is empty. At the same time, the sidewalls  282  cover a predetermined region of sidewalls of the housing  210 . 
     The second O-ring groove  215  and third O-ring groove  216  are disposed between the cap  280  and the housing  210 , thereby helping close a space therebetween. 
     In the atmospheric pressure plasma apparatus  200  according to the first embodiment of the present subject matter, if power supply is applied to the first and second electrodes  240  and  260 , as shown in  FIGS. 1 and 4 , the source gas  202  is phase-changed into a plasma state in the isolating space  251  of the first and second electrode  240  and  260 . 
     As mentioned previously, the source gas  202  is supplied through the source-gas supplying pipe  213  and the source-gas guide region  223  from the outside to the source-gas chamber  242 . Then, the source gas  202  is supplied through the first electrode  240  from the source-gas chamber  242  to the isolating space  251 . 
     The plasma is injected to the outside through the first connecting hole  262  of the second electrode  260 . Due to the cover  270  of  FIGS. 1 and 4 , the plasma is injected to the mixing groove  271 . 
     The secondary gas  201  supplied from the outside fills the secondary gas chamber  211 , and then injected through the ceramic nozzle  290  from the second electrode  260  to the outside or the mixing groove  271 . 
     The secondary gas  201  injected to the outside or the mixing groove  217  and the source gas  202  phase-changed into plasma is changed into conformal mixed gas  203  to be injected into a processing object or a processing region. 
     According to the first embodiment of the atmospheric pressure plasma apparatus  200 , the source gas  202  passes the first electrode  240  to be supplied to the isolating space  251  equivalent to a plasma generating region. Such the source gas  202  is phase-changed into plasma in the plasma generating region, and then conformally injected to the outside through the first connecting hole  124  of the second electrode  120 . The secondary gas  201  passes the isolating space  251  through the ceramic nozzle  290  with isolating the plasma generated in the plasma generating region. Then, the secondary gas  201  is injected through the ceramic nozzle  290  protruded from the second electrode  260  as mush as a predetermined length and mixed with the plasma injected through the first connecting hole  262  to be conformally dissolved. As a result, the reagent of the secondary gas  201  is improved. 
     At this time, it does not mean that the secondary gas  201  is dissolved in the plasma generating region to be injected to the outside, but that the secondary gas  201  is reacted with the plasma in the outside to be dissolved, so that the movable course of the dissolved secondary gas  201  becomes shortened, thereby minimizing the loss of reagent of the dissolved secondary gas  201 . 
     In the atmospheric pressure plasma apparatus  100  in accordance with the present subject matter, the first connecting hole  262  and the ceramic nozzle  290  are conformally arranged on the second electrode  260 , thereby generating conformal plasma in the light of space. Also, the secondary gas  180  dissolved by the plasma is conformally generated, thereby improving the dissolvability of the secondary gas  201 . 
     As mentioned above, the atmospheric pressure plasma apparatus  200  may be used in numerous applications such as modifying surface properties of materials, etching, coating, sterilization, disinfecting, generating ozone, dyeing, cleaning waste water, cleaning faucet water, air cleaning, and high-gain lamps, and nanotube growing. 
     EXAMPLE 2 
       FIGS. 5A and 5B  are partial cross-sectional perspective views of an atmospheric pressure plasma apparatus in accordance with a second embodiment of the present subject matter.  FIG. 5B  is a magnify drawing of region B of the  FIG. 5B . 
     Referring to  FIGS. 5A and 5B , an atmospheric pressure plasma apparatus  300  according to a second embodiment of the present subject matter is the same as that according to the first embodiment of the present subject matter exception that elements correspond to the nozzle holder  220 , the first electrode  240 , and the ceramic nozzle  290  of the first embodiment of the present subject matter. 
     The same parts as those described in the first embodiment are represented with like reference numerals and their explanation will be omitted. 
     A nozzle insulator  320   a  is mounted on an apparatus mounting part  210   b  of the housing  210 . In this case, the nozzle insulator  320   a  is formed in a chalet shape like the nozzle holder  220  of the first embodiment. The bottom center of the nozzle insulator  320   a  is empty. 
     The nozzle holder  320   a  is shown as disk-shaped and is mounted on the nozzle holder  220  according to the first embodiment. The nozzle holder  320   a  according to the second embodiment is formed in a shape such that only a center part of the bottom  221 , including the third penetrating hole  224  of the nozzle holder  220 , is separated. 
     As shown in  FIGS. 5A and 5B , one end of the base tube  391  is embedded with the third penetrating hole  224 , and the other end of is connected to the first electrode  340 , corresponding to the first electrode  240  of the first embodiment. Resultantly, the base tube  391  is connected from the nozzle holder  320   b  to the first electrode  340 . 
     In this case, the base tube  391  does not penetrate the nozzle holder  320   b  and the first electrode  340 , and is embedded in a predetermined depth. 
     The ceramic nozzle  390  is inserted into the base tube  391  to be fastened at predetermined depth on the other end of the base tube  391 . As described in first embodiment, the ceramic nozzle  390  is protruded at predetermined length. 
     In the second embodiment, the elements are the same those as described in the first embodiment exception of the nozzle insulator  320   a , the nozzle holder  320   b , the base tube  391 , the ceramic nozzle  390 , and the second electrode  360 . 
     That is, the nozzle holder  220  of the first embodiment is formed as one body. In the second embodiment, the nozzle insulator  320   a  and the nozzle holder  320   b  are separated. Also, whereas the ceramic nozzle  290  is disposed as one body from the nozzle holder  220  to the second electrode  260  in the first embodiment, the base tube  391  is disposed from the nozzle holder  320   b  to the half way of the first electrode  340 , and the ceramic nozzle  390  is disposed from the base tube  391  to the second electrode  360 . Except for the herein described differences between the first and second embodiments, other elements, and their effects may be the same. 
       FIG. 6  shows the flow of source gas of the atmospheric pressure plasma apparatus according to the first embodiment of the present subject matter. 
     Referring to  FIG. 6 , the current velocity of the source gas  202  in the source gas chamber  225  of the atmospheric pressure plasma apparatus  200  is measured. As shown in  FIG. 6 , the flow of the source gas  202  supplied through the source gas supplying pipe  213  in the source-gas guide region  223  is conformal as a whole. 
     This means that the source gas  202  is conformally distributed in the source gas chamber  225 . Such conformal distribution means that the source gas  202  contact with the first electrode  240  is conformal, and the source gas  202  penetrating the first electrode  240  is also conformal. 
     Thus, the source gas  202  passing over the first electrode  240  is conformal, thereby conformally providing the source gas  202  to the isolating space  251  being the plasma generating region. As a result, conformal plasma can be created. 
     As shown in  FIG. 6 , the uniform flow of the source gas  202  in the source gas chamber  225  means that the plasma created in the atmospheric pressure plasma apparatus  200  is generated conformally. 
     According to the present subject matter, the atmospheric pressure plasma apparatus is capable of minimizing the loss of reagent of dissolved secondary gas. 
     In addition, the atmospheric pressure plasma apparatus is capable of generating plasma that is uniformed in the light of space. 
     Further, the atmospheric pressure plasma apparatus enhances the dissolvability of the secondary gas by uniformly mixing the plasma and the secondary gas. 
     Although various embodiments of the present subject matter have been described herein for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the subject matter as disclosed in the accompanying claims.