Patent Publication Number: US-2007102119-A1

Title: Plasma processing system and plasma processing method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This is a continuation-in-part of Application PCT/JP02/01111, filed Feb. 8, 2002, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a plasma processing system and a plasma processing method.  
      2. Related Background Art  
      In semiconductor fabrication processes, plasma processing systems which make required processing on semiconductor wafers (here in after simply called a wafer), objects-to-be-processed with plasmas are used.  
      Such plasma processing systems include those using inductive coupled plasmas (ICP) and those using capacitive coupled plasmas (CCP). The inductive coupled plasmas, which have higher plasma density than the capacitive coupled plasmas and have 10-20 V bias voltages which are lower than 100-200 V bias voltages of the capacitive coupled plasmas, can make highly efficient processing on wafers with little damage.  
      G FIG. 5A  is a sectional view of one example of the conventional plasma etching systems using the inductive coupled plasmas. The plasma etching system  200  comprises a chamber  201  having a susceptor  203  disposed inside for a wafer to be mounted on, a belljar  202  disposed on the chamber  201  with the interior communicated with the interior of the chamber  201 , an antenna  205  wound on the outer periphery of the belljar  202 , a high-frequency bias electric power source  204  connected to the susceptor  203 , and a high-frequency electric power source  206  connected to the antenna  205 . High-frequency electric power is supplied to the antenna  205  from the high-frequency electric power source  206 , whereby induced electromagnetic fields are generated in the belljar  203  to generate plasmas of a processing gas. The wafer is processed with the plasmas.  
      However, in such plasma etching system  200 , electric fields which are slant from the antenna  205  toward the susceptor  203  as indicated by the arrow in  FIG. 5A , and the slant electric fields cause the etchant to be incident on the wafer surface as shown in  FIG. 5B  especially immediately after the plasmas are ignited. Resultantly, problems that configurations of micronized patterns are broken, and that electrons are slantly incident on the wafer surface, and charges are accumulated.  
      As means for removing the slant electric fields which is a cause for such problems, Specification of Japanese Patent Application Unexamined Publication No. 1993-206072, for example, discloses the use of a Faraday shield. As exemplified in  FIG. 5C , the Faraday shield  207  is a cylindrical member of a conductor disposed between the belljar  202  and the antenna  205  of the plasma etching system  200 ′ and acts to short the components parallel with the axial direction of the Faraday shield  207  to remove the vertical components of the electric fields, whereby the generation of the slant electric fields is prevented. However, thus removing the vertical electric fields weakens the electric components effective to ignite the plasmas, which causes a problem of making the plasma ignition difficult.  
      In view of such circumferences, the present invention provides a plasma processing system and a plasma processing method which use inductive coupled plasmas and are free from the problems due to the slant electric fields generated immediately after plasmas have been ignited. Another object of the present invention is to provide a plasma processing system and a plasma processing method which can ignite the plasmas without failure even with the use of a Faraday shield in the conductive coupled plasma system.  
     SUMMERY OF THE INVENTION  
      To solve the above-described problems, according to one aspect of the present invention, the present invention provides a plasma processing system comprising a processing vessel including a housing unit for containing a substrate-to-be-processed and a plasma generating unit communicated with the housing unit and having an insulator wall, for performing plasma processing on the substrate-to-be-processed; a conducting mount disposed in the housing unit, for the substrate-to-be-processed to be mounted on; antenna means disposed on the outside of the insulator wall, for forming induced electromagnetic fields in the plasma generating unit; a first high-frequency electric power source for supplying high-frequency electric power to the antenna means; gas supply means for supplying a plasma generating gas which is dissociated by the induced electromagnetic fields generated by the antenna means, and a processing gas for the plasma processing; a conducting member disposed outside the insulator wall, opposed to the mount; and a second high-frequency electric source for supplying high-frequency electric power to the mount.  
      According to the aspect of the present invention, the present invention includes the conducting member disposed on the outside of the insulator wall, opposed to the mount, and the second high-frequency electric power source for supplying high-frequency electric power to the mount, whereby when plasmas are ignited, high-frequency electric power is supplied from the second high frequency electric power source to the mount to generate electric fields between the mount and the conducting member to thereby create a state where the electric fields generated between the mount and the conducting member dominant. Accordingly, the generation of the unpreferable influences due to electric fields generated slant to a substrate-to-be-processed can be suppressed.  
      According to a second aspect of the present invention, the present invention provides a plasma processing system comprising a chamber for housing a substrate-to-be processed; a belljar disposed on the chamber in communication with the chamber and having a side wall and a top wall of an insulator; a conducting mount disposed in the chamber, for the substrate-to-be-processed to be mounted on; an antenna means disposed on the outside of the side wall of the belljar, for generating induced electromagnetic fields in the belljar; a first high-frequency electric power source for supplying high-frequency electric power to the antenna means; gas supply means for supplying a plasma generating gas which is dissociated by the induced electromagnetic fields generated by the antenna means to be plasmas, and a processing gas for the plasma processing; a conducting member disposed upper of the top wall, opposed to the mount; and a second high-frequency electric power source for supplying high-frequency electric power to the mount.  
      According to the second aspect, the present invention includes the conducting member disposed upper of the top wall, opposed to the mount, and the second high-frequency electric power source for supplying high frequency electric power to the mount, whereby when plasmas are ignited, high frequency electric power is supplied from the second high-frequency electric power source to the mount to thereby generate electric fields vertical to a substrate-to-be-processed between the mount and the conducting member, whereby a state where electric fields vertical to the substrate-to-be-processed are dominant can be created. Accordingly the unpreferable influences due to the electric fields slant to the substrate-to-be-processed can be suppressed without failure.  
      Furthermore, according to a third aspect of the present invention, the present invention provides a plasma processing system comprising a chamber for housing a substrate-to-be-processed; a belljar disposed on the chamber in communication with the chamber and having a side wall and a top wall of an insulator; a conducting mount disposed in the chamber, for the substrate-to-be-processed to be mounted on; an antenna means disposed on the outside of the side wall of the belljar, for generating induced electromagnetic fields in the belljar; a first high-frequency electric power source for supplying high-frequency electric power to the antenna means; gas supply means for supplying a plasma generating gas which is dissociated by the induced electromagnetic fields generated by the antenna means to be plasmas, and a processing gas for the plasma processing; a Faraday shield disposed between the belljar and the antenna means; a conducting member disposed upper of the top wall, opposed to the mount; and a second high-frequency electric power source for supplying high-frequency electric power to the mount.  
      According to the third aspect, the present invention includes the Faraday shield disposed between the belljar and the antenna means, the conducting member disposed upper of the topwall, opposed to the mount, and the second high-frequency electric power source for supplying high frequency electric power to the mount, whereby when plasmas are ignited, high frequency electric power is supplied from the second high-frequency electric power source to the mount to generate electric fields vertical to a substrate-to-be-processed between the mount and the conducting member to thereby apply the electric fields required for the plasma ignition. Accordingly, the plasma ignition can be ensured while generation of the electric fields slant to the substrate-to-be-processed by using the Faraday shield can be avoided.  
      In the present invention according to any one of the first to the third aspects, preferably the mount includes a heating mechanism for heating the substrate-to-be-processed to thereby accelerate the reaction of the plasma processing.  
      According to a fourth aspect of the present invention, the present invention provides a plasma processing method for performing plasma processing by using a plasma processing system comprising a chamber for housing a substrate-to-be-processed; a belljar disposed on the chamber in communication with the chamber and having a side wall and a top wall of an insulator; a conducting mount disposed in the chamber, for the substrate-to-be-processed to be mounted on; an antenna means disposed on the outside of the side wall of the belljar, for generating induced electromagnetic fields in the belljar; a first high-frequency electric power source for supplying high-frequency electric power to the antenna means; gas supply means for supplying a plasma generating gas which is dissociated by the induced electromagnetic fields generated by the antenna means to be plasmas, and a processing gas for the plasma processing; a conducting member disposed upper of the top wall, opposed to the mount; and a second high-frequency electric power source for supplying high-frequency electric power to the mount, high-frequency electric power being supplied from the second high-frequency electric power source to the mount to generate electric fields vertical to the substrate-to-be-processed between the mount and the conducting member and generate plasmas, and then high-frequency electric power being supplied from the first high-frequency electric power source to the antenna means to generate induced electromagnetic fields in the belljar and generate inductive coupled plasmas, whereby the plasma processing is made on the substrate-to-be-processed.  
      According to the fourth aspect, in the present invention, high-frequency electric power is supplied from the second high frequency electric power source to the mount to generate electric fields vertical to a substrate-to-be-processed between the mount and the conducting member to thereby generate plasmas, then high frequency electric power is supplied from the first high-frequency electric power source to the antenna means to thereby generate induced electromagnetic fields in the belljar to generate inductive coupled plasmas in the belljar, whereby the plasma processing is made on the substrate-to-be-processed. This makes it possible to generate the electric fields vertical to a substrate-to-be-processed between the mount and the conducting member and generate the plasmas before the induced electromagnetic fields are generated, whereby the electric fields slant to a substrate-to-be-processed are prohibited from affecting a substrate-to-be-processed immediately after the plasma ignition, which is a problem in igniting plasmas by induced electromagnetic fields.  
      Furthermore, according to a fifth aspect of the present invention, the prevent invention provides a plasma processing method for performing plasma processing by using a plasma processing system comprising a chamber for housing a substrate-to-be-processed; a belljar disposed on the chamber in communication with the chamber and having a side wall and a top wall of an insulator; a conducting mount disposed in the chamber, for the substrate-to-be-processed to be mounted on; an antenna means disposed on the outside of the side wall of the belljar, for generating induced electromagnetic fields in the belljar; a first high-frequency electric power source for supplying high-frequency electric power to the antenna means; gas supply means for supplying a plasma generating gas which is dissociated by the induced electromagnetic fields generated by the antenna means to be plasmas, and a processing gas for the plasma processing; a Faraday shield disposed between the belljar and the antenna means; a conducting member disposed upper of the top wall, opposed to the mount; and a second high-frequency electric power source for supplying high-frequency electric power to the mount, high-frequency electric power being supplied from the second high-frequency electric power source to generate electric fields between the mount and the conducting member to ignite plasmas, and then, high-frequency electric power being supplied from the first high-frequency electric power source to the antenna means to generate induced electromagnetic fields in the belljar to generate inductive coupled plasmas, whereby the plasma processing is made on the substrate-to-be-processed.  
      According to the fifth aspect, high frequency electric power is supplied from the second high frequency electric source to the mount to generate electric field between the mount and the conducting member to ignite plasmas, and then high frequency electric source is supplied from the first high frequency electric power source to the antenna means to generate induced electromagnetic fields in the belljar to generate inductive coupled plasmas, whereby the plasma processing is made on a substrate-to-be-processed. The electric fields are generated between the mount and the conducting member before the induced electromagnetic fields are generated, whereby the electric fields required for the plasma ignition can be applied by the electric fields generated between the mount and the conducting member, whereby the plasma ignition can be ensured even in the inductive coupled plasma processing by using the Faraday shield which prevents the generation of the electric field slant to a substrate-to-be-processed.  
      According to the fourth or the fifth aspect, it is preferable that the first high frequency electric power source starts supplying high frequency electric power after the second high frequency electric power source has started supplying high frequency electric power, whereby plasmas are ignited by the electric fields generated by the high frequency electric power from the second high frequency electric power source, and after the plasma ignition, the plasma processing is made by the inductive coupled plasmas generated by the high frequency electric power from the first high frequency electric power source. In this case, it is preferable that the second high frequency electric power source stops supplying the high frequency electric power after the first high frequency electric power source has started supplying the high frequency electric power. This prevents the generation of high bias voltages in a substrate-to-be-processed.  
      In the above-described plasma processing method, it is preferable to make the plasma processing while a substrate-to-be-processed is being heated. This can accelerate the reaction of the plasma processing.  
      The above-described plasma processing method is suitably applicable to the processing for removing natural oxide films formed on a substrate-to-be-processed. In this case,as the plasma generating gas and the processing gas, argon gas and hydrogen gas are suitably used. In place of argon, inert gases, such as neon gas, helium gas, xenon gas, etc. can be used.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a block diagram of a metal deposition system including a pre-cleaning apparatus to which the plasma processing system according to a first embodiment of the present invention is applied.  
       FIG. 2  is a diagrammatic sectional view of the plasma processing system according to the first embodiment of the present invention.  
      FIG. 3  is a perspective view of the Faraday shield of the pre-cleaning apparatus shown in  FIG. 2 .  
       FIG. 4  is a diagrammatic sectional view of the pre-cleaning apparatus according to a second embodiment of the present invention.  
       FIG. 5A  is a diagrammatic sectional view of one example of the conventional plasma etching system using inductive coupled plasmas.  
       FIG. 5B  is a view showing motions of an etchant of the conventional plasma etching system using the inductive couple plasmas.  
       FIG. 5C  is a diagrammatic sectional view of one example of the conventional plasma etching system using a Faraday shield. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      A first embodiment of the present invention will be explained below with reference to the drawings attached hereto.  
       FIG. 1  is a block diagram of a metal deposition system having a pre-cleaning apparatus to which the plasma processing system according to a first embodiment of the present invention is applied. The metal deposition system  20  is of the multi-chamber type comprising a transfer chamber  10  disposed at the center, and two cassette chambers  11 ,  12 , a dressing chamber  13 , a Ti film deposition apparatus  14 , the pre-cleaning apparatus  15  the present embodiment relates to, TiN deposition apparatus  16 , an Al deposition apparatus  17  (a tungsten (W) deposition apparatus in a case that metal layers of tungsten (W) are deposited, but in the present embodiment, the Al deposition apparatus  17  is exemplified), and a cooling chamber  18 , which are arranged around the transfer chamber  10 .  
      In this metal deposition system  20 , a barrier layer is formed on a semiconductor wafer (hereinafter simply called a wafer W) with contact holes or via holes formed in, and an Al (aluminum) layer is formed on the barrier layer to fill the holes and form the Al interconnection. Specifically, one sheet of wafer W is taken out of the cassette chamber  11  by a carrier arm  19  to be loaded into the pre-cleaning apparatus  15  and have natural oxide films formed on the surface of the wafer W removed. Then, the wafer W is loaded into the dressing chamber  13  to be degassed. Then, the wafer W is loaded into the Ti deposition apparatus  14  to have a Ti film deposited on, then further loaded into the TiN deposition apparatus  16  to have a TiN film deposited as a barrier layer. Then, in the Al deposition apparatus  17 , an Al layer is deposited on the wafer W. The prescribed deposition processing is completed here, and then the wafer W is cooled in the cooling chamber  18  and loaded into the cassette chamber  12 .  
      Thus, a device including, for example, on a wafer having an inter-layer insulation film with contact holes formed in down to dopant diffused regions, a barrier layer formed in the dopant diffused regions and on the inter-layer insulation film, and a metal layer formed on the barrier layer and connected to the dopant diffused regions is fabricated.  
      Then, the pre-cleaning apparatus  15  according to the present embodiment mounted on the metal deposition system  20  will be detailed below. As shown in  FIG. 2 , the pre-cleaning apparatus  15  comprises a substantially cylindrical chamber  31  and a substantially cylindrical belljar  32  continuously disposed on the chamber  31 . In the chamber  31 , a susceptor (mount)  33  of a conducting material for horizontally supporting a wafer W, an object-to-be-processed is arranged, supported by a cylindrical support member  35 . A conducting member  49  of a conducting material is disposed upper of the belljar  32 , opposed to the susceptor  33 .  
      The conducting member  49  is formed of a metal of high conductivity, e.g., Al (aluminum) and is a disc (at least the surface opposed to the belljar  32  is flat) having substantially the same diameter as that of a wafer or the susceptor  33  and a 1-5 mm thickness. The conducting member  49  is disposed upper of the belljar  32 , opposed to the susceptor  33 . The conducting member  49  may be mounted on the belljar  32  but may be disposed, a little spaced from the top surface of the belljar.  
      The conducting member  49  is grounded to GND to thereby generate electric fields vertical to the susceptor  33  between the conducting member  49  and the susceptor  33 .  
      The susceptor  33  is connected to a second high-frequency electric power source  34 , and the second high-frequency electric power source  34  supplies high-frequency electric power to the susceptor  33  to generate electric fields vertical to the wafer W between the susceptor  33  and the conducting member  49 . A heater  36  is buried in the susceptor  33 , and an electric power source  37  supplies electric power to the heater  36  to heat the wafer to a prescribed temperature.  
      The belljar  32  is formed of an electrically insulating material, e.g., quartz, ceramics or others, and a substantially cylindrical Faraday shield  44  having slits  44   a  longitudinally opened at a prescribed pitch is disposed around the belljar  32 . A coil  42  as an antenna member is wound around the outer periphery of the Faraday shield  44 . The coil  42  is connected to a first high-frequency electric power source  43  of, e.g., 450 kHz, and the first high-frequency electric power source  43  supplies high-frequency electric power to the coil  42  to generate induced electromagnetic fields in the belljar  32 . The Faraday shield  44  functions to prevent the generation of electric fields which are slant from the coil  42  toward the susceptor  33 .  
      A clamp ring  38  which can press the wafer W mounted on the susceptor  33 , clamping the outer edge of the wafer W is disposed upper of the susceptor  33  and can be moved up and down by a lift mechanism not shown. The clamp ring  38 is moved up to a prescribed position when a wafer W is carried into the chamber  31  and transferred onto the support pins (not shown) provided on the susceptor  33 , and when the wafer is mounted on the susceptor  33  by withdrawing the support pins (not shown) to be held, the clamp ring  38  is moved down to a position where the clamp ring  38  clamps the wafer in contact with the outer edge of the wafer W.  
      The chamber  31  has an opening  46  in the side wall. A gate valve  47  is provided on the outside of the chamber  31  at the position opposed to the opening  46 . With the gate valve  47  opened, a wafer W is carried between a load-lock chamber (not shown) and the chamber  31  communicated with each other. A gas supply nozzle  48  is provided in the side wall of the chamber  31 , and the gas supply nozzle  48  feeds gases from a gas supply mechanism  60  into the chamber  31  and the belljar  32 .  
      The gas supply mechanism  60  has an Ar gas supply source  61  which supplies Ar gas as a plasma generating gas and an H 2  gas supply source  62  which supplies H 2  gas as a processing gas for etching. The Ar gas supply source  61  is connected to a gas line  63 . A mass flow controller  67  is inserted in the gas line  63 , and opening/closing valves  65 ,  69  are inserted before and after the mass flow controller  67 . The H 2  gas supply source  62  is connected to a gas line  64 . A mass flow controller  68  is inserted in the gas line  64 , and opening/closing valves  66 ,  70  are inserted before and after the mass flow controller  68 . The gas lines  63 ,  64  are connected to a gas line  71 . The gas line  71  is connected to the gas supply nozzle  48 .  
      An exhaust pipe  50  is connected to the bottom wall of the chamber  31 . The exhaust pipe  50  is connected to exhaust means  51  including a vacuum pump. The exhaust means  51  is operated to thereby maintain a prescribed vacuum degree in the chamber  31  and the belljar  32 .  
      Then, the operation of removing natural oxide films formed on a wafer W by the pre-cleaning apparatus  15  of the above-described structure will be explained.  
      First, the gate valve  47  is opened, and a wafer W is carried into the chamber  31  by the carrier arm  19  disposed in the carrier chamber  10  and transferred onto the support pins (not shown) of the susceptor  33 . Next, the support pins are withdrawn into the susceptor  33  to thereby mount the wafer on the susceptor  33 , and then the clamp ring  38  is lowered to clamp the wafer W at the outer edge thereof. Next, the gate valve  47  is closed, and the interior of the chamber  31  and the belljar  32  is exhausted by the exhaust means  51  to be place under a prescribed decreased pressure. Under the decreased pressure, the Ar gas is fed at a prescribed flow rate from the Ar gas supply source  61  into the chamber  31  and the belljar  32  while high-frequency electric power is supplied from the second high-frequency electric power source  34  to the susceptor  33  to thereby generate, between the susceptor  33  and the conducting member  48 , electric fields which are vertical to the wafer W. The Ar gas is excited by the electric fields to ignite plasmas.  
      After the plasma ignition, the supply of high-frequency electric power from the first high-frequency electric power source  43  to the coil  42  is started to generate induced electromagnetic fields in the belljar  32  while the supply of the high-frequency electric power from the second high-frequency electric power source  34  to the susceptor  33  is stopped. Hereafter the plasmas are retained by the induced electromagnetic fields. If necessary, the supply of the high-frequency electric power from the second high-frequency electric power source may be retained after the start of the supply of the high-frequency electric power from the first high-frequency electric power source  43 . In this state, with the flow rate of the Ar gas from the Ar gas supply source  61  decreased, the supply of the H 2  gas from the H 2  gas supply source  62  into the chamber  31  is started, and the processing for etching off natural oxide films on the wafer W is performed while the wafer W is being heated by the heater  36 . At this time, the Faraday shield  44  prohibits the coil  42  from generating electric fields slant to the surface of the wafer W, whereby the breakage of a pattern configuration on the surface of the wafer W and the charge accumulation in the wafer W due to the incidence of the ions and electrons on the surface of the wafer W can be prevented. Inductive coupled plasmas, whose bias voltage is intrinsically low, cause little damage.  
      The natural oxide films on the wafer W are thus removed, and then, a displacement of the exhaust means  51 , an Ar gas flow rate from the Ar gas supply source  61  and an H 2  gas flow rate from the H 2  gas supply source  62  are adjusted to make a vacuum degree in the chamber  31  and the belljar  32  equal to that in the carrier chamber  10  while the support pins are projected out of the susceptor  33  to lift the wafer W, and the gate valve  47  is opened to advance the carrier arm  19  into the chamber  31  to take out the wafer W. The step in the pre-cleaning apparatus  15  is thus completed.  
      As conditions for this process, for example, the electric power of the first high-frequency electric power source  43  can be 500-1000 W, and the frequency is 450 kHz, the electric power of the second high-frequency electric power source  34  is 500-1000 W, and the frequency is 13.56 MHz, the heating temperature of the heater  36  can be 50-500° C., and the pressure in the chamber  31  can be 0.133-13.3 Pa (0.1-100 mTorr). The Ar gas can be supplied at a suitable flow rate of a range of 0-0.050 L/min (0-50 scam), and the H 2  gas can be supplied at a suitable flow rate of a range of 0-0.200 L/min (0-200 sccm). In more details, the Ar gas flow rate at the time of the ignition can be 0.050 L/min (50 sccm), and the Ar gas flow rate/H 2  gas flow rate at the time of the processing can be 0.008/0.012 L/min(8/12 sccm).  
      The above-described plasma processing can suitably remove natural oxide films on, e.g., Si, CoSi, W, WSi and TiSi. In the conventional plasma processing system of the inductive coupled plasma type, removing electric fields slant from the coil  42  toward the susceptor  33  by using the Faraday shield  44  weakens the electric fields, which disadvantageously makes it difficult to ignite the plasmas. However, the above-described structure ensures the ignition of the plasmas by the electric field generated between the susceptor  33  and the conducting member  49 , and the plasma ignition can be followed by the step of the pre-cleaning using the inductive coupled plasmas generated by the induced electric electromagnetic fields.  
      Such use of the inductive coupled plasmas can assist the plasmas with the magnetic filed components, whereby the ratio of the H 2  can be increased while the ratio of the Ar can be decreased. Furthermore, the plasma density and the bias voltage can be controlled independently of each other, which permits the bias voltage to be low while permitting the plasma density to be high. These can make the removal of the natural oxide films very efficient. The capacitive coupled plasmas are not stable, which does not permit to decrease the Ar, and the plasma density and the bias voltage cannot be controlled independently of each other. The capacitive coupled plasmas cannot remove natural oxide film so efficiently.  
      Then, a second embodiment of the present invention will be explained.  
       FIG. 4  is a sectional view of a pre-cleaning apparatus the plasma processing system according to the present embodiment is applied to. The pre-cleaning apparatus  15 ′ has the same structure as the pre-cleaning apparatus  15  according to the first embodiment except that in the former the Faraday shield  44  is not provided. Such pre-cleaning apparatus  15 ′ performs the processing operation for removing natural oxide films formed on a wafer W that, as is done in the pre-cleaning apparatus  15  according to the first embodiment, high-frequency electric power is supplied from the second high-frequency electric power source  34  to the susceptor  33  to ignite plasmas, and then high-frequency electric power is supplied from the first high-frequency electric power source  43  to the coil  42  to generate inductive coupled plasmas to remove the natural oxide films formed on the wafer W.  
      In the present embodiment, when the plasmas are ignited, as described above, the high-frequency electric power is supplied from the second high-frequency electric power source  34  to the susceptor  33  prior to the supply of the high-frequency electric power source from the first high-frequency electric power source  43 , so as to generate electric fields vertical to a wafer W between the susceptor  33  and the conducting member  49 , whereby the state where the electric fields vertical to the wafer W are dominant can be created. Accordingly, the state where slant electric fields which tend to cause the deterioration of a surface state of a wafer W, and disadvantages of charge accumulation, etc. due to the slant electric fields are not generated, whereby the deterioration of a surface state of a wafer W and influences of charge accumulation, etc. can be reduced. After the plasmas have been thus ignited, the high-frequency electric power is supplied from the first high-frequency electric power source  43  to the coil  42 , whereby the plasma processing can be performed with the inductive coupled plasmas highly efficiently and with little damage, as is done in the first embodiment.  
      The present invention is not limited to the above-described embodiments and can cover other various modifications. In the above-described embodiment, the present invention is applied to the pre-cleaning apparatus of the metal deposition system, which removes natural oxide films but is applicable to, e.g., other plasma etching systems which perform contact etching, etc. Furthermore, the present invention is applicable to plasma etching systems for plasma CVD, etc. This plasma processing system may comprise a conventional inductive coupled plasma processing system having a grounded conductor plate mounted on the belljar. Making simple reforms as described above on the conventional system can make the system cost of the present invention very low. Furthermore, the substrates to be processed are not essentially semiconductor wafers and can be other substrates.  
      As described above, according to the present invention the conduction member is disposed on the outside of the insulator wall, and the second high-frequency electric power source for supplying high-frequency electric power to the mount are provided, whereby when plasmas are ignited, high-frequency electric power is supplied from the second high-frequency electric power source to the mount to generate electric fields between the mount and the conducting member to thereby make the electric fields generated between the mount and the conducting member dominant in the processing chamber so as to suppress unpreferable influences caused by the electric fields generated slant to a substrate-to-be-processed.  
      According to the present invention, the conducting member is provided upper of the top wall, opposed to the mount, and the second high-frequency electric power source for supplying high-frequency electric power to the mount, whereby when plasmas are ignited, high-frequency electric power is supplied from the second high-frequency electric power source to the mount to generate electric fields vertical to a substrate-to-be-processed between the mount and the conducting member, whereby the state where electric fields vertical to the substrate-to-be-processed are dominant is created to thereby suppress without failure the unpreferable influences caused by the electric fields generated slant to the substrate-to-be-processed. Thus, a plasma processing system and a plasma processing method which can perform processing of high precision and efficiency can be provided.  
      Furthermore, according to the present invention, the Faraday shield is provided between the belljar and the antenna, the conducting member is disposed opposed to the mount, upper of the mount, the second high-frequency electric power source for supplying high-frequency electric power to the mount is provided, and when plasmas are ignited, high-frequency electric power is supplied from the second high-frequency electric power source to the mount to generate electric fields vertical to a substrate-to-be-processed between the mount and the conducting member to thereby generate the electric fields necessary to ignite the plasma. Accordingly, while the generation of the electric fields slant to a substrate-to-be-processed is prevented by the Faraday shield, the plasma ignition can be ensured. Thus, a plasma processing system and a plasma processing method which has solved the problem that makes it difficult to ignite the plasma in the inductive coupled plasma system using the Faraday shield can be realized.