Abstract:
A substrate processing apparatus includes: a process chamber including a chamber lid and a chamber body to provide a reaction space therein; a source electrode in the process chamber; a radio frequency (RF) power source for supplying an RF power to the source electrode; a feeding line connecting the source electrode and the RF power source; and a shielding part wrapping the feeding line to block an electric field.

Description:
[0001]    This application claims the benefit of Korean Patent Application No. 10-2010-0063491, filed on Jul. 1, 2010, which is hereby incorporated by a reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to a power supplying means having a shielding means for a feeding line, and more particularly, to a power supplying means having a shielding means capable of blocking an electric field between a feeding line and an exterior and a substrate processing apparatus including the power supplying means. 
       BACKGROUND 
       [0003]    In general, a semiconductor device, a display device and a solar cell are fabricated through a depositing process where a thin film is formed on a substrate, a photolithographic process where a thin film is selectively exposed and shielded by a photosensitive material and an etching process where a thin film is selectively removed. Among the fabricating processes, the deposition process and the etching process are performed in a substrate processing apparatus under an optimum vacuum state using a plasma. 
         [0004]    In the depositing process and the etching process, it is required to uniformly supply an active process gas or an ionized process gas onto the substrate by a plasma discharge. However, when an integrated plate electrode or a split electrode divided into plurality is used for the plasma discharge, it is difficult to obtain a uniform plasma density in the reaction space due to various factors. 
       SUMMARY 
       [0005]    Accordingly, the present disclosure is directed to a power supplying means having a shielding means for a feeding line and a substrate processing apparatus including the same that substantially obviate one or more of the problems due to limitations and disadvantages of the related art. 
         [0006]    An object of the present disclosure is to provide a power supplying means where a shielding means for preventing transmission of an electric field from the feeding line to an exterior or from the exterior to the feeding line is formed to wrap a feeding line connecting a radio frequency (RF) power source and a plasma source electrode and a substrate processing apparatus including the power supplying means. 
         [0007]    Another object of the present disclosure is to provide a power supplying means where a circulation space is defined between a feeding line and a shielding means and a circulating means for exhausting a heat radiated from the feeding line is formed for the circulation space and a substrate processing apparatus including the power supplying means. 
         [0008]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a substrate processing apparatus includes: a process chamber including a chamber lid and a chamber body to provide a reaction space; a source electrode in the process chamber; a radio frequency (RF) power source supplying an RF power to the source electrode; a feeding line connecting the source electrode and the RF power source; and a shielding means wrapping the feeding line to block an electric field. 
         [0009]    In another aspect, a power supplying means for supplying a radio frequency (RF) power to a source electrode in a process chamber includes: an RF power source supplying the RF power to the source electrode; a feeding line connecting the source electrode and the RF power source; and a shielding means wrapping the feeding line to block an electric field. 
         [0010]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention. 
           [0012]    In the drawings: 
           [0013]      FIG. 1  is a cross-sectional view showing a substrate processing apparatus according to an embodiment of the present invention; 
           [0014]      FIG. 2  is a plan view showing a plasma source electrode of a substrate processing apparatus according to an embodiment of the present invention; 
           [0015]      FIG. 3  is a perspective view showing a power supplying means according to an embodiment of the present invention; 
           [0016]      FIG. 4  is a perspective view showing a feeding line of a power supplying means according to an embodiment of the present invention; 
           [0017]      FIG. 5  is a cross-sectional perspective view showing a supporting means of a power supplying means according to an embodiment of the present invention; 
           [0018]      FIG. 6  is a cross-sectional view showing a feeding line and a plasma source electrode of a substrate processing apparatus according to an embodiment of the present invention; 
           [0019]      FIG. 7  is an exploded perspective view showing a shielding means of a power supplying means according to an embodiment of the present invention; 
           [0020]      FIG. 8  is a plan view showing a power supplying means according to an embodiment of the present invention; 
           [0021]      FIG. 9  is a cross-sectional view showing a power supplying means according to an embodiment of the present invention; 
           [0022]      FIGS. 10 and 11  are graphs showing an electric field in a power supplying means without a shielding means; and 
           [0023]      FIGS. 12 and 13  are graphs showing an electric field in a power supplying means having a shielding means according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    Reference will now be made in detail to embodiments which are illustrated in the accompanying drawings. Wherever possible, similar reference numbers will be used to refer to the same or similar parts. 
         [0025]      FIG. 1  is a cross-sectional view showing a substrate processing apparatus according to an embodiment of the present invention. 
         [0026]    In  FIG. 1 , a substrate processing apparatus  110  includes a process chamber  112 , a plurality of plasma source electrodes  114 , a power supplying means  122 , a plurality of protruding portions  170 , a gas distributing means  118  and a susceptor  116 . The substrate processing apparatus  110  may further include a gas inlet pipe  172 , an edge frame  120 , a gate valve (not shown) and an exhaust port  124 . 
         [0027]    The process chamber  112  provides a reaction space by combination of a chamber lid  112   a  and a chamber body  112   b.  The chamber lid  112   a  and the chamber body  112   b  may be combined to each other with an O-ring  112   c  interposed therebetween. The plurality of plasma source electrodes  114  used as a source electrode are combined to the chamber lid  112   a  corresponding to an interior of the process chamber  112 . A plurality of insulating plates  162  are formed between the plurality of plasma source electrodes  114  and the chamber lid  112   a  and electrically insulate the plurality of plasma source electrodes  114  from the chamber lid  112   a.  The plurality of plasma source electrodes  114  and the chamber lid  112   a  are combined to each other with the plurality of insulating plates  162  interposed therebetween using a connecting means such as a bolt. 
         [0028]    The susceptor  116  is disposed in the process chamber  112  to face the plurality of plasma source electrodes  114  and is used as a plasma ground electrode. In addition, the plurality of protruding portions  170 , the chamber lid  112   a  and the chamber body  112   b  as well as the susceptor  116  may be used as a plasma ground electrode. A substrate  164  is loaded on the susceptor  116 , and the susceptor  116  includes a substrate supporting plate  116   a  having an area greater than the substrate  164  and a supporting shaft  116   b  capable of moving the substrate supporting plate  116   a.  A heater  166  may be formed in the substrate supporting plate  116   a  for heating up the substrate  164 . In the substrate processing apparatus  110 , the susceptor  116  may be grounded similarly to the process chamber  112 . In another embodiment, an additional radio frequency (RF) power may be applied to the susceptor  116  or the susceptor  116  may have an electrically floating state according to conditions of the process for the substrate  164 . 
         [0029]    A plasma discharge space is defined between the plurality of plasma source electrodes  114  and the susceptor  116 . When a process gas is supplied to the plasma discharge space, the process gas is activated or ionized between the plurality of plasma source electrodes  114  and the susceptor  116  and is supplied onto the substrate  164  on the susceptor  116 . As a result, a process for the substrate  164  such as a deposition of a thin film on the substrate  164  or an etching of a thin film on the substrate  164  is performed. 
         [0030]    A first gap distance between each plasma source electrode  114  and the susceptor  116  is the same as a second gap distance between each protruding portion  170  and the susceptor  116 . Since the plurality of insulating plates  162  are interposed between the chamber lid  112   a  and each plasma source electrode  114 , a first thickness of each plasma source electrode  114  is smaller than a second thickness of each protruding portion  170 . In addition, the second thickness of each protruding portion  170  is the same as a sum of the first thickness of each plasma source electrode  114  and a third thickness of each insulating plate  162 . 
         [0031]    For the purpose of preventing non-uniform process due to a standing wave effect, at least one of the plurality of plasma source electrodes  114  may have a width smaller than a wavelength of an RF wave. As a result, a standing wave effect is prevented by the plurality of plasma source electrodes  114  and a uniform plasma density may be kept in the reaction space. 
         [0032]    The power supplying means  122  applying an RF power to each of the plurality of plasma source electrodes  114  includes an RF power source  126  supplying the RF power, a matcher  130  for impedance matching, a feeding line  160  connected to the plurality of plasma source electrodes  114  and a shielding means  150  for the feeding line  160 . The plurality of plasma source electrodes  114  are connected in parallel to the RF power source  126 , and the matcher  130  for impedance matching is connected between the plurality of plasma source electrodes  114  and the RF power source  126 . 
         [0033]    The RF power source  126  may use a very high frequency (VHF) wave having a wavelength band of about 20 MHz to about 50 MHz that has excellent plasma generation efficiency. The feeding line  160  includes a main feeding line  160   a  and a plurality of auxiliary feeding lines  160   b.  The main feeding line  160   a  connects the plurality of auxiliary feeding lines  160   b  to the RF power source  126 . The plurality of auxiliary feeding lines  160   b  penetrate the chamber lid  112   a  and the plurality of insulating plates  162  and are connected to the plurality of plasma source electrodes  114 , respectively. At least one of the plurality of auxiliary feeding lines  160   a  may be connected to both end portions or a central portion of at least one of the plurality of plasma source electrodes  114 . 
         [0034]    The plurality of protruding portions  170  are combined to the chamber lid  112   a  between the two adjacent plasma source electrodes  114 . The plurality of plasma source electrodes  114  and the plurality of protruding portions  170  are disposed to be parallel to each other. In addition, the plurality of protruding portions  170  are disposed at a periphery of the chamber lid  112   a  adjacent to a sidewall of the process chamber  112 . Accordingly, the plurality of plasma source electrodes  114  and the plurality of protruding portions  170  are alternately disposed with each other between the two outermost protruding portions  170 . 
         [0035]    The plurality of protruding portions  170  may be combined to the chamber lid  112   a  between the two adjacent plasma source electrodes  114  using a connecting means such as a bolt. Alternatively, the plurality of protruding portions  170  may be integrated with the chamber lid  112   a  as a single body. The chamber lid  112   a  and the plurality of protruding portions  170  are electrically connected to each other. 
         [0036]    The chamber lid  112   a  may have a rectangular shape and at least one of the plurality of plasma source electrodes  114  may have a stripe shape having longer and shorter axes. The plurality of plasma source electrodes  114  may be disposed to be parallel to each other and spaced apart from each other by the same gap distance. Similarly, at least one of the plurality of protruding portions  170  may have a stripe shape having longer and shorter axes, and the plurality of protruding portions  170  may be disposed to be parallel to each other and spaced apart from each other by the same gap distance. In another embodiment, at least one of the plurality of plasma source electrodes  114  and at least one of the plurality of protruding portions  170  may have various shape as necessary. 
         [0037]    The plurality of plasma source electrodes  114 , the plurality of protruding portions  170 , the chamber lid  112   a,  the chamber body  112   b  and the susceptor  116  may be formed of a metallic material such as aluminum and stainless steel, and the plurality of insulating plates  162  may be formed of a ceramic material such as aluminum oxide. 
         [0038]    The gas distributing means  118  is formed in each of the plurality of plasma source electrodes  114  and the plurality of protruding portions  170 . The gas distributing means  118  includes a plurality of first gas distributing means  118   a  respectively in the plurality of plasma source electrodes  114  and a plurality of second gas distributing means  118   b  respectively in the plurality of protruding electrodes  170 . The plurality of first gas distributing means  118   a  spray a first process gas and the plurality of second gas distributing means  118   b  spray a second process gas. The first and second process gases may be the same as each other or may be different from each other. 
         [0039]    Although the plurality of first gas distributing means  118   a  are formed in the plurality of plasma source electrodes  114  and the plurality of second gas distributing means  170  are formed in the plurality of protruding portions  170  in  FIG. 1 , the gas distributing means  118  may be formed exclusively in the plurality of plasma source electrodes  114  or exclusively in the plurality of protruding portions  170  in another embodiment. Further, when the gas distributing means  118  is formed in the plurality of plasma source electrodes  114 , the plurality of protruding portions  170  may be omitted. 
         [0040]    The edge frame  120  is formed on an inner wall of the process chamber  112  and extends over a periphery of the substrate  164 . When the susceptor  116  moves up to be located at a process position, the edge frame  220  blocks the periphery of the substrate  164  to prevent formation of a thin film on the periphery of the substrate  164 . The edge frame  120  has an electrically floating state. 
         [0041]    A reaction gas in the reaction space is outputted through the exhaust port  124  so that a vacuum state of the reaction space can be controlled. A vacuum pump (not shown) may be connected to the exhaust port  124 . 
         [0042]      FIG. 2  is a plan view showing a plasma source electrode of a substrate processing apparatus according to an embodiment of the present invention. 
         [0043]    In  FIG. 2 , the plurality of plasma source electrodes  114  are disposed to be parallel to and spaced apart from each other. In addition, the plurality of plasma source electrodes  114  are connected in parallel to the RF power source  126  through the feeding line  160 . The matcher  128  for impedance matching is connected between the feeding line  160  and the RF power source  126 . The feeding line  160  includes the main feeding line  160   a  connected to the RF power source  126  and the plurality of auxiliary feeding lines  160   b  connect the main feeding line  160   a  and both ends of the plurality of plasma source electrodes  114 . 
         [0044]      FIG. 3  is a perspective view showing a power supplying means according to an embodiment of the present invention. 
         [0045]    In  FIG. 3 , the feeding line  160  and the shielding means  150  are formed on an outer surface of the chamber lid  112   a  corresponding to the exterior of the process chamber  112  (of  FIG. 1 ). For convenience of illustration, the gas inlet pipe  172  of  FIG. 1  is omitted and the plurality of plasma source electrodes  114  combined to an inner surface of the chamber lid  112   a  corresponding to the interior of the process chamber  112  are shown in dotted line. In addition, a housing  132  accommodating the gas inlet pipe (of  FIG. 1 ) is formed on the outer surface of the chamber lid  112   a.    
         [0046]    The power supplying means  122  includes the RF power source  126  (of  FIG. 1 ), the matcher  130  (of  FIG. 1 ), the feeding line  160  connected to the plurality of plasma source electrodes  114 , the shielding means  150  electrically shielding the feeding line  160  and a supporting means  158  supporting the feeding line  160 . 
         [0047]    The feeding line  160  includes the main feeding line  160   a  connected to the RF power source  126  (of  FIG. 1 ), the plurality of auxiliary feeding lines  160   b  connected to the main feeding line  160   a,  a plurality of connecting lines  160   c  connected to the plurality of auxiliary feeding lines  160   b  and a plurality of feeding rods  160   d  connecting the plurality of connecting lines  160   c  and the plurality of plasma source electrodes  114 . The plurality of auxiliary feeding lines  160   b  may be symmetrically disposed with respect to first and second horizontal reference lines passing the main feeding line  160   a.  The first and second horizontal reference lines are perpendicular to each other and perpendicular to the main feeding line  160   a.  When the plurality of auxiliary feeding lines  160   b  are symmetrically formed, the RF power may be further uniformly applied to the plurality of plasma source electrodes  114 . 
         [0048]    When the plasma is discharged in the process chamber  112  by applying the RF power to the plurality of plasma source electrodes  114 , electric interference may be caused among the plurality of auxiliary feeding lines  160   b  and among the plurality of connecting lines  160   c  connected to the plasma source electrodes  114 . Accordingly, it may be difficult to obtain a uniform electric field distribution over the substrate  164  (of  FIG. 1 ) corresponding to the plurality of plasma source electrodes  114 . In addition, the plasma may be non-uniformly distributed in the reaction space of the process chamber  112  due to the non-uniform electric field distribution. As a result, the non-uniform plasma distribution may degrade the uniform deposition of a thin film or the uniform etching of a thin film. 
         [0049]    For the purpose of preventing the electric interference among the plurality of auxiliary feeding lines  160   b  and among the plurality of connecting lines  160   c,  the shielding means  150  is formed to wrap the feeding line  160 . The shielding means  150  includes a first shielding cover  150   a  and a plurality of second shielding covers  150   b.  The first shielding cover  150   a  shields the plurality of auxiliary feeding lines  160   b,  and the plurality of second shielding covers  150   b  shield the plurality of connecting lines  160   c.    
         [0050]    To shield the plurality of auxiliary feeding lines  160   b  parallel to the chamber lid  112   a  with ease, a region where the plurality of auxiliary feeding lines  160   b  are disposed may be divided into a plurality of shielding regions and the first shielding cover  150   a  may include a plurality of first shielding covers  150   a.  When the plurality of first shielding covers  150   a  are used, the region for the plurality of auxiliary feeding lines  160   b  may be divided into four shielding regions with respect to the first and second horizontal reference lines passing the main feeding line  160   a  and four first shielding covers  150   a  may be used for the four shielding regions so that the four first shielding covers  150   a  can be assembled with ease. The number of the first shielding covers  150   a  may vary according to the division number and the area of the plurality of auxiliary feeding lines  160   b.    
         [0051]    The first shielding cover  150   a  includes a lower piece  154   a  under the plurality of auxiliary feeding lines  160   b  and an upper piece  154   b  over the plurality of auxiliary feeding lines  160   b.  The lower and upper pieces  154   a  and  154   b  are combined to each other to wrap the plurality of auxiliary feeding lines  160   b.  The plurality of second shielding covers are disposed over the upper surface of the chamber lid  112   a  and are combined to the lower piece  154   a  of the first shielding cover  150   a  to shield the plurality of connecting lines  160   c  and the plurality of feeding rods  160   d.  The chamber lid  112   a  contacts and supports the plurality of second shielding covers  150   b.  The plurality of second shielding covers  150   b  may be not combined to the chamber lid  112   a.    
         [0052]    The upper piece  154   b  of the first shielding cover  150   a  covers an open portion formed by the lower piece  154   a  and the plurality of second shielding covers  150   b . Accordingly, a planar area of the lower piece  154   a  is smaller than a planar area of the upper piece  154   b.    
         [0053]    The first shielding cover  150   a  and the plurality of second shielding covers  150   b  may be formed of a metallic material such as aluminum. When the first shielding cover  150   a  and the plurality of second shielding covers  150   b  are assembled for shielding the feeding line  160 , the first shielding cover  150   a  and the plurality of second shielding covers  150   b  are electrically connected to each other. In addition, the shielding means  150  including the first shielding cover  150   a  and the plurality of second shielding covers  150   b  is electrically connected to the chamber lid  112   a  to be grounded. At least one ground line  156  connected to the chamber lid  112   a  may be formed between two adjacent second shielding covers  150   b  for increasing ground paths from the shielding means  150 . 
         [0054]    The plurality of second shielding covers  150   b  may be disposed in two symmetrical rows with respect to the second horizontal reference line that passes the main feeding line  160   a  and is perpendicular to a longer axis of each of the plurality of plasma source electrodes  114 . In addition, the plurality of connecting lines  160   c  and the plurality of feeding rods  160   d  connected to both ends of each plasma source electrode  114  may be disposed in two symmetrical rows with respect to the second horizontal reference line. The at least one ground line  156  may be formed between two adjacent second shielding covers  150   b  in each symmetrical row. 
         [0055]      FIG. 4  is a perspective view showing a feeding line of a power supplying means according to an embodiment of the present invention. 
         [0056]    In  FIG. 4 , the gas inlet pipe  172  of  FIG. 1  is omitted, and the plurality of plasma source electrodes  114  combined to an inner surface of the chamber lid  112   a  corresponding to the interior of the process chamber  112  (of  FIG. 1 ) are shown in dotted line for convenience of illustration. 
         [0057]    The feeding line  160  includes the main feeding line  160   a,  the plurality of auxiliary feeding lines  160   b,  the plurality of connecting lines  160   c  and the plurality of feeding rods  160   d.  One end of the main feeding line  160   a  is connected to the RF power source  126  (of  FIG. 1 ) and is formed to be perpendicular to the chamber lid  112   a.  The other end of the main feeding line  160   a  is connected to the plurality of auxiliary feeding lines  160   b  parallel to the chamber lid  112   a.  The main feeding line  160   a  is divided into the plurality of auxiliary feeding lines  160   b  so that the RF power can be uniformly applied to the plurality of plasma source electrodes  114 . 
         [0058]    The plurality of auxiliary feeding lines  160   b  include a plurality of first branch lines  152   a  connected to the main feeding line  160   a,  a plurality of second branch lines  152   b  respectively connected to the plurality of first branch lines  152   a,  a plurality of third branch lines  152   c  respectively connected to the plurality of second branch lines  152   b  and a plurality of fourth branch lines  152   d  respectively connected to the plurality of third branch lines  152   c . The number of branch lines of the plurality of auxiliary feeding lines  160   b  may vary as necessary. 
         [0059]    The plurality of first branch lines  152   a,  the plurality of second branch lines  152   b , the plurality of third branch lines  152   c  and the plurality of fourth branch lines  152   d  are disposed to be parallel to the chamber lid  112   a.  The plurality of connecting lines  160   c  are connected to the plurality of fourth branch lines  152   d,  respectively. The plurality of first branch lines  152   a,  the plurality of second branch lines  152   b,  the plurality of third branch lines  152   c,  the plurality of fourth branch lines  152   d  and the plurality of connecting lines  160   c  may have a plate shape. The plurality of connecting lines  160   c  are perpendicular to the chamber lid  112   a  and are respectively connected to the plasma source electrodes  114  with the plurality of feeding rods  160   d  interposed therebetween. 
         [0060]    A connecting plate  156   a  expanding parallel to the chamber lid  112   a  is formed at an end of each of the plurality of connecting lines  160   c  for connection to the plurality of feeding rods  160   d.  A penetration hole is formed in the connecting plate  156   a.  Each of the plurality of feeding rods  160   d  may penetrate the connecting plate  156   a  through the penetration hole and an upper end of each of the plurality of feeding rods  160   d  is supported by the connecting plate  156   a.  The plurality of feeding rods  160   d  penetrate the connecting plate  156   a  and an airtight plate  148  and are combined to the plurality of plasma source electrodes  114 . The connecting plate  156   a  directly contacts the airtight plate  148 . In addition, a screw thread may be formed at a lower end of each of the plurality of feeding rods  160   d  for combination to the plurality of plasma source electrodes  114 . 
         [0061]      FIG. 5  is a cross-sectional perspective view showing a supporting means of a power supplying means according to an embodiment of the present invention. 
         [0062]    In  FIG. 5 , the supporting means  158  may be formed to be plural in number for supporting the plurality of auxiliary feeding lines  160   b.  The supporting means  158  is disposed over the housing  132  and penetrates the lower piece  154   a  of the first shielding cover  160   a.  The supporting means  158  supports the plurality of auxiliary feeding lines  160   b  parallel to the chamber lid  112   a  for preventing the plurality of auxiliary feeding lines from sagging. 
         [0063]    The supporting means  158  includes a supporting body  158   a  that is disposed over the housing  132  and has a cylindrical shell shape, a protruding connector  158   b  that is connected to the supporting body  158   a  and penetrates the lower piece  154   a  of the first shielding cover  160   a,  a combination hole  158   c  that is formed at a center of the protruding connector  158   b,  a supporting rod  158   d  that is inserted through the combination hole  158   c  and supports the plurality of auxiliary feeding lines  160   b  and a coupling part  158   e  that is combined to the protruding connector  158   b.    
         [0064]    The protruding connector  158   b  having a cylindrical shape has a radius smaller than the supporting body  158   a.  A screw thread is formed on an inner surface of the protruding connector  158   b  and on an outer surface of the supporting rod  158   d  so that the protruding connector  158   b  and the supporting rod  158   d  can be combined to each other in screw connection. The coupling part  158   e  has a hollow hole accommodating the protruding connector  158   b.  The supporting body  158   a,  the protruding connector  158   b  and the coupling part  158   e  may be formed of an insulating material such as Teflon, and the supporting rod  158   d  may be formed of a metallic material such as copper (Cu). 
         [0065]      FIG. 6  is a cross-sectional view showing a feeding line and a plasma source electrode of a substrate processing apparatus according to an embodiment of the present invention. 
         [0066]    In  FIG. 6 , a coupling hole  136   a  is formed in the plasma source electrode  114  and an inlet hole  136   b  is formed in the chamber lid  112   a  and the insulating plate  162  so that the feeding rods  160   d  can be electrically connected to both ends of the plasma source electrode  114 . The feeding rod  160   d  is inserted through the hollow hole of the connecting plate  156   a  at the end of the plurality of connecting lines  160   c,  the inlet hole  136   b  and the coupling hole  136   a  and is combined to the plasma source electrode  114 . When the feeding rod  160   d  is combined to the plasma source electrode  114 , an insulator is formed in the inlet hole  136   b  corresponding to the chamber lid  112   a  for electrically isolating the feeding rod  160   d  and the chamber lid  112   a.    
         [0067]    For the purpose of electrically connecting the feeding rod  160   d  and the plasma source electrode  114  with airtight kept, the airtight plate  148  is combined to the chamber lid  112   a  corresponding to the plasma source electrode  114  using a bolt  184  with an O-ring (not shown) interposed therebetween. A screw thread is formed at the coupling hole  136   a  of the plasma source electrode  114  and on an end of the feeding rod  160   d  so that the feeding rod  160   d  and the plasma source electrode  114  can be combined to each other in screw thread. The airtight plate  148  may be formed of an insulating material as ceramic. 
         [0068]      FIG. 7  is an exploded perspective view showing a shielding means of a power supplying means according to an embodiment of the present invention. 
         [0069]    In  FIG. 7 , the shielding means  150  includes the first shielding cover  150   a  shielding the plurality of auxiliary feeding lines  160   b  (of  FIG. 3 ) and the plurality of second shielding covers  150   b  shielding the plurality of connecting lines  160   c  (of  FIG. 3 ). 
         [0070]    The first shielding cover  150   a  includes the lower and upper pieces  154   a  and  154   b  combined to each other. The lower piece  154   a  includes a first accommodating portion  186   a  which the feeding line  160  (of  FIG. 3 ) is disposed over, a fence portion  186   b  formed along a perimeter of the first accommodating portion  186   a,  a first connecting portion  186   c  combined to the plurality of second shielding covers  150   b  and a through hole  186   d  which the supporting means  158  penetrates through. The upper piece  154   b  includes a plate portion  188   a  which the feeding line  160  is disposed under and a plurality of circulation holes  188   b  connected to a circulating means (not shown) for exhausting a heat radiated from the feeding line  160 . 
         [0071]    Each of the plurality of second shielding covers  150   b  includes a pipe  190   a  which has a rectangular pillar shell shape including a hollow hole accommodating the plurality of connecting lines  160   c,  a passing portion  190   b  which the plurality of fourth branch lines  152   d  (of  FIG. 4 ) penetrate through, a second connecting portion  190   c  at both sides of the passing portion  190   b  combined to the lower piece  154   a  and a communicating portion  190   d.  The passing portion  190   b  is formed by eliminating an upper portion of the pipe  190   a  and the communicating portion  190   d  is formed by eliminating a lower portion of the pipe  190   a.  In addition, the second connecting portion  190   c  of each of the plurality of second shielding covers  150   b  corresponds to the first connecting portion  186   c  of the lower piece  154   a  of the first shielding cover  150   a.    
         [0072]    The lower piece  154   a  of the first shielding cover  150   a  is combined to the plurality of second shielding covers  150   b,  and the open portion formed by the lower piece  154   a  of the first shielding cover  150   a  and the plurality of second shielding covers  150   b  is covered with the upper piece  154   b  of the first shielding cover  150   a.  Accordingly, the upper piece  154   b  has a planar area greater than the lower piece  154   a.    
         [0073]      FIG. 8  is a plan view showing a power supplying means according to an embodiment of the present invention. 
         [0074]    In  FIG. 8 , the upper piece  154   b  of the first shielding means  150   a  is omitted, and the plurality of auxiliary feeding lines  160   b,  the lower piece  154   a  of the first shielding means  150   a  and the plurality of second shielding means  150   b  are shown for convenience of illustration. 
         [0075]    Each of the plurality of connecting lines  160   c  adjacent to the first shielding cover  150   a  penetrates through the hollow hole of each of the plurality of second shielding covers  150   b.  The connecting plate  156   a,  which is connected to the end of each of the plurality of connecting lines  160   c  and expands parallel to the first shielding cover  150   a,  is disposed at a central portion of each of the plurality of second covers  150   b.  The connecting plate  156   a  of each of the plurality of second shielding covers  150   b  and each of the plurality of plasma source electrodes  114  (of  FIG. 6 ) are connected to each other through each of the plurality of feeding rods  160   d  (of  FIG. 6 ). In addition, the hollow hole of each of the plurality of second shielding covers  150   b  has a size capable of accommodating the airtight plate  148  that is used for keeping airtight when the feeding rod  160   d  and the plasma source electrodes  114  are connected to each other. The airtight plate  148  may protrude outside each of the plurality of second shielding covers  150   b  through the communicating portion  190   d.    
         [0076]      FIG. 9  is a cross-sectional view showing a power supplying means according to an embodiment of the present invention. 
         [0077]    In  FIG. 9 , when the shielding means  150  is assembled for shielding the feeding line  160 , a circulation space is defined between the feeding line  160  and the shielding means  150 . When the RF power is applied to the plurality of plasma source electrodes  114  (of  FIG. 1 ) through the feeding line  160 , a heat is radiated from the feeding line  160 . For the purpose of preventing accumulation of the heat in the circulation space between the feeding line  160  and the shielding means  150 , the plurality of circulation holes  188   b  are formed in the upper piece  154   b  of the first shielding means  150   a  and a circulating means such as a fan (not shown) injecting external air into or through the plurality of circulation holes  188   b  is connected to the upper piece  154   b.  The air injected through the plurality of circulation holes  188   b  is circulated through the circulation space between the feeding line  160  and the shielding means  150  and is exhausted through the communicating portion  190   d  of each of the plurality of second shielding covers  150   b.    
         [0078]      FIGS. 10 and 11  are graphs showing an electric field in a power supplying means without a shielding means, and  FIGS. 12 and 13  are graphs showing an electric field in a power supplying means having a shielding means according to an embodiment of the present invention.  FIGS. 10 to 13  show a simulation result where a variation in electric field distribution according to with or without a shielding means is predicted. 
         [0079]    In  FIGS. 10 and 12 , an x-axis represents a position along a shorter axis of the plasma source electrode  114  (of  FIG. 2 ), a y-axis represents a position along a longer axis of the plasma source electrode  114  (of  FIG. 2 ) and a z-axis represents an electric field intensity in voltage per meter (V/m). In addition, the electric field intensity increases as the color becomes bright, and the electric field intensity decreases as the color becomes dark. 
         [0080]    In  FIGS. 11 and 13 , an x-axis represents a position along a shorter axis of the plasma source electrode (of  FIG. 2 ) and a y-axis represents an electric field intensity. In addition, variations in electric field distribution according to an RF power are calculated. 
         [0081]    When the feeding line is not wrapped by the shielding means, the electric field has non-uniform peaks as shown in  FIGS. 10 and 11 . As a result, it becomes difficult to process the substrate uniformly due to the non-uniform peaks of the electric field. When the feeding line is wrapped by the shielding means, the electric field has uniform peaks as shown in  FIGS. 12 and 13 . As a result, the substrate is uniformly processed with the electric field having uniform peaks. 
         [0082]    Consequently, in a substrate processing apparatus according to the present invention, since a shielding means wraps a feeding line connecting an RF power source and a plasma source electrode, transmission of an electric field from the feeding line to an exterior or from the exterior to the feeding line is prevented. In addition, since interference in an electric field is prevented, a uniform plasma density is obtained in a reaction space and the substrate is uniformly processed. 
         [0083]    Further, when an RF power is applied to a plasma source electrode through a feeding line, a heat radiated from the feeding line may be accumulated in a circulation space between the feeding line and a shielding means and the accumulated heat may deteriorate the RF power applied to the plasma source electrode. Since an air in the circulation space is exhausted by a circulating means, the heat accumulation in the circulation space is prevented. 
         [0084]    It will be apparent to those skilled in the art that various modifications and variations can be made in a power supplying means having a shielding means and a substrate processing apparatus including the power supplying means of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.