Abstract:
A substrate processing method for a substrate processing system comprising at least a substrate processing apparatus that subjects a substrate to processing, and a substrate transferring apparatus having a transferring device that transfers the substrate, which enables the yield to be increased without bringing about a decrease in the throughput. The substrate processing method comprises a jetting step of jetting a high-temperature gas onto at least one of the transferring device and the substrate transferred by the transferring device.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a substrate processing system, a substrate processing method, and a storage medium. 
   2. Description of the Related Art 
   In a process of manufacturing a semiconductor device or an FPD (Flat Panel Display) such as a liquid crystal display from a substrate, there is a problem of preventing the substrate from being contaminated by particles that get in from outside the manufacturing apparatus or are produced in the manufacturing apparatus. In particular, if a stage provided in a reduced pressure processing chamber of the manufacturing apparatus is contaminated with particles, then the particles will become attached to a rear surface of the substrate mounted on the stage, so that the contamination escalates in subsequent processes, resulting in the yield of the semiconductor devices ultimately manufactured decreasing. 
   As such particles, one can envisage, for example, ones brought in from outside the reduced pressure processing chamber, ones formed by deposit being detached through contact between the stage and the substrate in the reduced pressure processing chamber, and deposit comprised of a product produced from a reactive gas. 
   Recently, the present applicants have thus proposed a method in which the temperature of the stage in the reduced pressure processing chamber is controlled, the temperature of the stage being made to be sufficiently higher or lower than a usual operating temperature, so that detachment of particles attached to the stage is induced through thermal stress, and furthermore have proposed a method in which the stage is held at a high temperature and a predetermined pressure is held so as to produce a thermophoretic force, whereby particles attached to the stage are scattered away from the stage (see, for example, Japanese Patent Application No. 2004-218939). 
   However, the substrate is not only contaminated by particles produced in the reduced pressure processing chamber, for example, particles attached to the stage on which the substrate is mounted, but rather is also contaminated during a transferring process of transferring the substrate. This arises in particular through transfer of particles attached to a transfer arm that transfers the substrate. To remove the particles attached to the transfer arm, operation of the transfer arm, and hence of a transfer chamber must be stopped; in particular, to stop the operation of a transfer chamber to which a plurality of processing chambers are connected, operation of all of the processing chambers must be stopped, and hence the throughput decreases markedly. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a substrate processing system, a substrate processing method, and a storage medium, that enable the yield to be increased without bringing about a decrease in the throughput. 
   To attain the above object, in a first aspect of the present invention, there is provided a substrate processing method for a substrate processing system comprising at least a substrate processing apparatus that subjects a substrate to processing, and a substrate transferring apparatus having a transferring device that transfers the substrate, the substrate processing method comprising a jetting step of jetting a high-temperature gas onto at least one of the transferring device and the substrate transferred by the transferring device. 
   According to the present aspect, the high-temperature gas is jetted onto the transferring means. As a result, particles attached to the transferring means are scattered away, and hence contamination of the transferring means can be prevented, and thus contamination can be prevented from being scattered onto the substrate transferred by the transferring means. Alternatively, the high-temperature gas is jetted onto the substrate transferred by the transferring means. As a result, particles attached to the substrate are scattered away, and hence contamination of the substrate can be prevented. Contamination of the substrate transferred by the substrate transferring apparatus can thus be prevented without stopping operation of the substrate transferring apparatus, and hence the yield can be increased without bringing about a decrease in the throughput. 
   Preferably, the jetting step comprises jetting the high-temperature gas onto the transferring device before the substrate is transferred by the transferring device. 
   According to the present aspect, the high-temperature gas is jetted onto the transferring means before the substrate is transferred by the transferring means. As a result, contamination of the substrate transferred by the transferring means can be prevented reliably. 
   Preferably, the high-temperature gas produces thermal stress on foreign matter attached to the at least one of the transferring device and the substrate transferred by the transferring device. 
   According to the present aspect, thermal stress is produced on foreign matter attached to at least one of the transferring means and the substrate transferred by the transferring means. As a result, the foreign matter can be scattered away by the thermal stress, and hence contamination of the transferring means and the substrate transferred by the transferring means can be prevented. 
   Preferably, the transferring device has a contacting portion that contacts the substrate, and the jetting step comprises jetting the high-temperature gas toward the contacting portion. 
   According to the present aspect, the high-temperature gas is jetted toward the contacting portion of the transferring means that contacts the substrate. As a result, foreign matter produced through the contact between the substrate and the contacting portion can be scattered away, and hence contamination of the transferring means can be prevented reliably. 
   Preferably, the jetting step comprises jetting the high-temperature gas onto the substrate before the substrate is transferred into the substrate processing apparatus by the transferring device. 
   According to the present aspect, the high-temperature gas is jetted onto the substrate before the substrate is transferred into the substrate processing apparatus by the transferring means. As a result, the temperature of the substrate can be increased in advance to a temperature reached in the substrate processing apparatus, and hence the state of temperature increase in the substrate processing apparatus can be made to be the same for all substrates. The processing results can thus be made to be uniform for all of the substrates, and hence the yield can be increased. 
   Preferably, moisture is attached to a surface of the substrate, and the jetting step comprises jetting the high-temperature gas toward the surface of the substrate. 
   According to the present aspect, the high-temperature gas is jetted toward a surface of the substrate to which moisture is attached. As a result, the moisture attached to the surface of the substrate can be evaporated off, and hence contamination of the substrate can be prevented. 
   Preferably, the substrate processing apparatus has a processing chamber in which the substrate is housed, and the jetting step comprises jetting the high-temperature gas into the processing chamber. 
   According to the present aspect, the high-temperature gas is jetted into the processing chamber of the substrate processing apparatus in which the substrate is housed. As a result, outgassing of moisture attached inside the processing chamber can be promoted, and hence the throughput can be improved. 
   Preferably, the substrate processing apparatus has a processing chamber in which the substrate is housed, adsorbed molecules are attached to a surface of the substrate, and the jetting step comprises jetting the high-temperature gas toward the surface of the substrate housed in the processing chamber. 
   According to the present aspect, the high-temperature gas is jetted toward the surface of the substrate housed in the processing chamber of the substrate processing apparatus, the surface of the substrate having adsorbed molecules attached thereto. As a result, the adsorbed molecules attached to the surface of the substrate can be scattered away inside the processing chamber, and hence corrosion due to scattering away of the adsorbed molecules outside the processing chamber can be prevented, and thus corrosion of the system can be prevented. 
   To attain the above object, in a second aspect of the present invention, there is provided a substrate processing system comprising at least a substrate processing apparatus that subjects a substrate to processing, and a substrate transferring apparatus having a transferring device for transferring the substrate, wherein the substrate transferring apparatus has a jetting device that jets a high-temperature gas onto at least one of the transferring device and the substrate transferred by the transferring device. 
   To attain the above object, in a third aspect of the present invention, there is provided a computer-readable storage medium storing a program for causing a computer to implement a substrate processing method for a substrate processing system comprising at least a substrate processing apparatus that subjects a substrate to processing, and a substrate transferring apparatus having a transferring device for transferring the substrate, the program comprising a jetting module for jetting a high-temperature gas onto at least one of the transferring device and the substrate transferred by the transferring device. 
   The above and other objects, features, and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view schematically showing the construction of a substrate processing system according to a first embodiment of the present invention; 
       FIG. 2  is a sectional view schematically showing the construction of a P/M appearing in  FIG. 1 ; 
       FIGS. 3A and 3B  are views schematically showing the shape of a pick of a transfer arm in an L/M appearing in  FIG. 1 ,  FIG. 3A  showing a plan view in a state with a wafer mounted on the pick, and  FIG. 3B  showing an enlarged perspective view of part of the pick around a tapered pad on the pick; 
       FIGS. 4A to 4C  are process drawings showing a method of removing particles from the tapered pad using thermal stress; 
       FIG. 5  is a view for explaining a watermark remaining on a wafer; and 
       FIGS. 6A to 6C  are process drawings showing a method of removing adsorbed molecules on a wafer using thermal stress. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present invention will be described in detail below with reference to the drawings. 
     FIG. 1  is a sectional view schematically showing the construction of a substrate processing system according to a first embodiment of the present invention. 
   As shown in  FIG. 1 , the substrate processing system  1  is comprised of a substrate processing apparatus (Process Module) (hereinafter referred to as “P/M”)  2  shown in  FIG. 2 , described below, which subjects semiconductor wafers (hereinafter referred to merely as “wafers”) W as substrates to plasma processing such as RIE (Reactive Ion Etching) or ashing, an atmospheric transfer apparatus  3  that removes each wafer W from a FOUP (Front Opening Unified Pod)  5  as a container housing the wafers W, and a load-lock module (hereinafter referred to as “LL/M”)  4  that is disposed between the atmospheric transfer apparatus  3  and the P/M  2 , and is for transferring each wafer W from the atmospheric transfer apparatus  3  into the P/M  2  and from the P/M  2  into the atmospheric transfer apparatus  3 . 
   Each of the P/M  2  and the LL/M  4  is constructed such that the interior thereof can be evacuated, while the interior of the atmospheric transfer apparatus  3  is always held at atmospheric pressure. Moreover, the P/M  2  and the LL/M  4 , and the LL/M  4  and the atmospheric transfer apparatus  3 , are connected together via gate valves  6  and  7  respectively. Each of the gate valves  6  and  7  can be opened and closed, so that the P/M  2  and the LL/M  4 , and the LL/M  4  and the atmospheric transfer apparatus  3 , can be communicated with one another or shut off from one another. Moreover, the interior of the LL/M  4  and the interior of the atmospheric transfer apparatus  3  are connected together via a communicating pipe  9  having an openable/closable valve  8  disposed part way therealong. 
   The atmospheric transfer apparatus  3  has a FOUP mounting stage  50  on which the FOUP  5  is mounted, an atmospheric loader module (hereinafter referred to as “L/M”)  51 , and a gas supply system  60  (jetting device) that supplies a high-temperature gas into the L/M  51 . 
   The FOUP mounting stage  50  is a stage having a flat upper surface. The FOUP  5  houses, for example, 25 wafers W, which are mounted in a plurality of tiers at equal pitch. The L/M  51  has a rectangular parallelepiped box shape, and has therein a SCARA-type transfer arm  52  for transferring the wafers W. 
   A shutter (not shown) is provided in a side of the L/M  51  on the FOUP mounting stage  50  side facing the FOUP  5  mounted on the FOUP mounting stage  50 . The FOUP  5  and the interior of the L/M  51  are communicated together when the shutter is opened. 
   The transfer arm  52  has an articulated transfer arm arm portion  53  which is constructed such as to be able to bend and extend, and a pick  54  shown in  FIG. 3A , described below, which is attached to a distal end of the transfer arm arm portion  53 . The pick  54  is constructed such that a wafer W is mounted directly thereon. Moreover, the transfer arm  52  has an articulated mapping arm  55  which is constructed such as to be able to bend and extend, a mapping sensor (not shown) that, for example, emits a laser beam so as to verify whether or not a wafer W is present being disposed at a distal end of the mapping arm  55 . A base end of each of the transfer arm arm portion  53  and the mapping arm  55  is linked to a rising/falling stage  58  that rises/falls along an arm base end supporting pillar  57  that is provided standing upright from a base  56  of the transfer arm  52 . Moreover, the arm base end supporting pillar  57  is constructed such as to be able to turn. In a mapping operation carried out for verifying the positions and number-of the wafers W housed in the FOUP  5 , in a state with the mapping arm  55  extended, the mapping arm  55  rises and falls, and verifies the positions and number of the wafers W in the FOUP  5 . 
   The transfer arm  52  can freely bend via the transfer arm arm portion  53 , and can freely turn via the arm base end supporting pillar  57 , and hence a wafer W mounted on the pick  54  can be freely transferred between the FOUP  5  and the LL/M  4 . 
   The gas supply system  60  has a gas introducing pipe  61  that penetrates through from outside the L/M  51  to inside the L/M  51  and is provided such that the end thereof inside the L/M  51  faces the transfer arm  52 , a gas supply apparatus (not shown) that is connected to an end of the gas introducing pipe  61  on the outside of the L/M  51 , a control valve  63  that is disposed in the gas introducing pipe  61  between the L/M  51  and the gas supply apparatus, and a heating unit  62  that is disposed in the gas introducing pipe  61  between the L/M  51  and the control valve  63 . In the present embodiment, the heating unit  62  preferably increases the temperature of supplied gas to a predetermined high temperature through heating over a short period of approximately 1 to 10 seconds. 
   In the present embodiment, the gas supply system  60  sprays a high-temperature gas heated by the heating unit  62  onto the transfer arm  52 , in particular the pick  54 , with a predetermined timing, thus removing particles attached to the transfer arm  52 . The details of the particle removal will be described later. 
   The LL/M  4  has a chamber  71  in which is disposed a transfer arm  70  that can bend, extend and turn, a gas supply system  72  (jetting means) that supplies an inert gas such as N 2  gas at a high temperature into the chamber  71 , and an LL/M exhaust system  73  that exhausts the interior of the chamber  71 . 
   The transfer arm  70  is a SCARA-type transfer arm comprising a plurality of arm portions, and has a pick  74  attached to a distal end thereof. The pick  74  is constructed such that a wafer W is mounted directly thereon. The shape of the pick  74  is like that of the pick  54 . 
   When a wafer W is to be transferred from the atmospheric transfer apparatus  3  into the P/M  2 , once the gate valve  7  has been opened, the transfer arm  70  receives the wafer W from the transfer arm  52  in the L/M  51 , and once the gate valve  6  has been opened, the transfer arm  70  enters into a chamber  10  of the P/M  2 , and mounts the wafer W on upper ends of pusher pins  33 , described below, which project out from an upper surface of a stage  12 . Moreover, when the wafer W is to be transferred from the P/M  2  into the atmospheric transfer apparatus  3 , once the gate valve  6  has been opened, the transfer arm  70  enters into the chamber  10  of the P/M  2  and receives the wafer W mounted on the upper ends of the pusher pins  33  projecting out from the upper surface of the stage  12 , and once the gate valve  7  has been opened, the transfer arm  70  passes the wafer W to the transfer arm  52  in the L/M  51 . 
   Note that the transfer arm  70  is not limited to being of a SCARA type, but rather may instead be of a frog leg type or a double arm type. 
   The gas supply system  72  has a gas introducing pipe  75  that penetrates through from outside the chamber  71  to inside the chamber  71 , a gas supply apparatus (not shown) that is connected to an end of the gas introducing pipe  75  on the outside of the chamber  71 , a control valve  77  that is disposed in the gas introducing pipe  75  between the chamber  71  and the gas supply apparatus, a heating unit  76  that is disposed in the gas introducing pipe  75  between the chamber  71  and the control valve  77 , and a gas supply port that is disposed at an end of the gas introducing pipe  75  on the inside of the chamber  71  and jets out an inert gas such as N 2  gas at a high temperature. In the present embodiment, there may be a pair of break filters  80  at an end of the gas supply port. In the present embodiment, the heating unit  76  preferably increases the temperature of the supplied inert gas such as N 2  gas to a predetermined high temperature through heating over a short period of approximately 1 to 10 seconds. 
   In the present embodiment, the gas supply system  72  sprays the high-temperature inert gas such as N 2  gas heated by the heating unit  76  onto the transfer arm  70 , in particular the pick  74 , in the chamber  71  with a predetermined timing, thus removing particles attached to the transfer arm  70 . The details of the particle removal will be described later. Moreover, the gas supply system  72  supplies the high-temperature inert gas such as N 2  gas into the chamber  71  with a predetermined timing, so as to control the pressure inside the chamber  71 . 
   Each of the break filters  80  is a mesh-like metal filter having a length thereof set to, for example, 200 mm, and is able to reduce or increase the area over which the high-temperature inert gas such as N 2  gas is jetted; the flow of the jetted high-temperature inert gas such as N 2  gas can thus be accelerated or decelerated, and hence the high-temperature inert gas such as N 2  gas can be jetted at a high pressure onto the transfer arm  70 , so as to remove particles attached to the transfer arm  70  effectively, or the high-temperature inert gas such as N 2  gas can be jetted uniformly over a broad area, so as to increase the pressure in the chamber  71  uniformly. 
   The L/LM exhaust system  73  has an exhaust pipe  78  that penetrates through into the chamber  71 , and a control valve  79  that is disposed part way along the exhaust pipe  78 ; the L/LM exhaust system  73  operates in collaboration with the gas supply system  72  described above to control the pressure in the chamber  71 . 
     FIG. 2  is a sectional view schematically showing the construction of the P/M  2  appearing in  FIG. 1 . 
   As shown in  FIG. 2 , the P/M  2  has a cylindrical chamber  10  made of aluminum having an inside wall thereof coated with alumite. A cylindrical stage  12  on which is mounted a wafer W having a diameter of, for example, 300 mm is disposed in the chamber  10 . 
   In the P/M  2 , an exhaust path  13  that acts as a flow path through which gas molecules above the stage  12  are discharged to the outside of the chamber  10  is formed between the inside wall of the chamber  10  and a side face of the stage  12 . An annular exhaust plate  14  that prevents leakage of plasma is disposed part way along the exhaust path  13 . A space in the exhaust path  13  downstream of the exhaust plate  14  bends round below the stage  12 , and is communicated with an automatic pressure control valve (APC valve)  15 , which is a variable butterfly valve. The APC valve  15  is connected to a turbo-molecular pump (TMP)  17 , which is an exhausting pump for evacuation, via an isolator valve  16 , and the TMP  17  is connected to a dry pump (DP)  19 , which is also an exhausting pump, via a valve  18 . The exhaust flow path (main exhaust line) comprised of the APC valve  15 , the isolator valve  16 , the TMP  17 , the valve  18  and the DP  19  is used for controlling the pressure in the chamber  10  using the APC valve  15 , and also for reducing the pressure in the chamber  10  down to a substantially vacuum state using the TMP  17  and the DP  19 . 
   Moreover, piping  20  is connected from between the APC valve  15  and the isolator valve  16  to the DP  19  via a valve  21 . The exhaust flow path (bypass line) comprised of the piping  20  and the valve  21  bypasses the TMP  17 , and is used for roughing the chamber  10  using the DP  19 . 
   A lower electrode radio frequency power source  22  is connected to the stage  12  via a feeder rod  23  and a matcher  24 . The lower electrode radio frequency power source  22  supplies predetermined radio frequency electrical power to the stage  12 . The stage  12  thus acts as a lower electrode. The matcher  24  reduces reflection of the radio frequency electrical power from the stage  12  so as to maximize the efficiency of the supply of the radio frequency electrical power into the stage  12 . 
   A disk-shaped ESC electrode plate  25  comprised of an electrically conductive film is provided in an upper portion of the stage  12 . A DC power source  26  is electrically connected to the ESC electrode plate  25 . A wafer W is attracted to and held on an upper surface of the stage  12  through a Johnsen-Rahbek force or a Coulomb force generated by a DC voltage applied to the ESC electrode plate  25  from the DC power source  26 . Moreover, an annular focus ring  27  is provided on the upper portion of the stage  12  so as to surround the wafer W attracted to and held on the upper surface of the stage  12 . The focus ring  27  is made of silicon, SiC (silicon carbide), or Qz (quartz), is exposed to a processing space S, described below, and focuses plasma in the processing space S toward a front surface of the wafer W, thus improving the efficiency of the plasma processing. 
   An annular coolant chamber  28  that extends, for example, in a circumferential direction of the stage  12  is provided inside the stage  12 . A coolant, for example cooling water or a Galden (registered trademark) fluid, at a predetermined temperature is circulated through the coolant chamber  28  via coolant piping  29  from a chiller unit (not shown). A temperature of the stage  12 , and hence of the wafer W attracted to and held on the upper surface of the stage  12 , is controlled through the temperature of the coolant. 
   A plurality of heat-transmitting gas supply holes  30  are provided in a portion of the upper surface of the stage  12  on which the wafer W is attracted and held (hereinafter referred to as the “attracting surface”) facing the wafer W. The heat-transmitting gas supply holes  30  are connected to a heat-transmitting gas supply unit  32  by a heat-transmitting gas supply line  31  provided inside the stage  12 . The heat-transmitting gas supply unit  32  supplies helium (He) gas as a heat-transmitting gas via the heat-transmitting gas supply holes  30  into a gap between the attracting surface of the stage  12  and a rear surface of the wafer W. The heat-transmitting gas supply holes  30 , the heat-transmitting gas supply line  31 , and the heat-transmitting gas supply unit  32  together constitute a heat-transmitting gas supply apparatus. Note that the type of the backside gas is not limited to being helium, but rather may also be an inert gas such as nitrogen (N 2 ), argon (Ar), krypton (Kr) or xenon (Xe), or oxygen (O 2 ) or the like instead. 
   Three pusher pins  33  are provided in the attracting surface of the stage  12  as lifting pins that can be made to project out from the upper surface of the stage  12 . The pusher pins  33  are connected to a motor (not shown) by a ball screw (not shown), and can be made to project out from the attracting surface of the stage  12  through rotational motion of the motor, which is converted into linear motion by the ball screw. The pusher pins  33  are housed inside the stage  12  when a wafer W is being attracted to and held on the attracting surface of the stage  12  so that the wafer W can be subjected to the plasma processing, and are made to project out from the upper surface of the stage  12  so as to lift the wafer W up away from the stage  12  when the wafer W is to be transferred out from the chamber  10  after having been subjected to the plasma processing. 
   A gas introducing shower head  34  (jetting means) is disposed in a ceiling portion of the chamber  10  facing the stage  12 . An upper electrode radio frequency power source  36  is connected to the gas introducing shower head  34  via a matcher  35 . The upper electrode radio frequency power source  36  supplies predetermined radio frequency electrical power to the gas introducing shower head  34 . The gas introducing shower head  34  thus acts as an upper electrode. The matcher  35  has a similar function to the matcher  24 , described earlier. 
   The gas introducing shower head  34  has a ceiling electrode plate  38  having a large number of gas holes  37  therein, and an electrode support  39  on which the ceiling electrode plate  38  is detachably supported. A buffer chamber  40  is provided inside the electrode support  39 . A gas introducing pipe  41  is connected from a gas supply apparatus (not shown) to the buffer chamber  40 . A piping insulator  42  is disposed in the gas introducing pipe  41  between the gas supply apparatus and the chamber  10 . The piping insulator  42  is made of an electrically insulating material, and prevents the radio frequency electrical power supplied to the gas introducing shower head  34  from leaking into the gas supply apparatus via the gas introducing pipe  41 . Moreover, a control valve  44  is disposed in the gas introducing pipe  41  between the gas supply apparatus and the piping insulator  42 , and a heating unit  43  is disposed in the gas introducing pipe  41  between the piping insulator  42  and the control valve  44 . In the present embodiment, the heating unit  43  preferably increases the temperature of a supplied processing gas to a predetermined high temperature through heating over a short period of approximately 1 to 10 seconds. 
   In the present embodiment, the high-temperature processing gas supplied from the gas introducing pipe  41  into the buffer chamber  40  is supplied by the gas introducing shower head  34  into the chamber  10  via the gas holes  37 . 
   A transfer port  64  for the wafers W is provided in a side wall of the chamber  10  in a position at the height of a wafer W that has been lifted up from the stage  12  by the pusher pins  33 . The gate valve  6  is provided in the transfer port  44  for opening and closing the transfer port  44 . 
   Upon supplying radio frequency electrical power to the stage  12  and the gas introducing shower head  34  in the chamber  10  of the P/M  2  as described above, and thus applying radio frequency electrical power into the processing space S between the stage  12  and the gas introducing shower head  34 , high-density plasma is produced from the processing gas supplied from the gas introducing shower head  34  into the processing space S; the wafer W is subjected to the plasma processing by the plasma. 
   Specifically, when subjecting a wafer W to the plasma processing in the P/M  2 , first, the gate valve  6  is opened, and the wafer W to be processed is transferred into the chamber  10 , and attracted to and held on the attracting surface of the stage  12  by applying a DC voltage to the ESC electrode plate  25 . Moreover, the processing gas (e.g. a mixed gas comprised of CF 4  gas, O 2  gas, and Ar gas with a predetermined flow ratio therebetween) is supplied from the gas introducing shower head  34  into the chamber  10  at a predetermined flow rate and flow ratio, and the pressure inside the chamber  10  is controlled to a predetermined value using the APC valve  15 . Furthermore, radio frequency electrical power is applied into the processing space S in the chamber  10  from the stage  12  and the gas introducing shower head  34 . The processing gas introduced in from the gas introducing shower head  34  is thus turned into plasma in the processing space S. The plasma is focused onto the front surface of the wafer W by the focus ring  27 , whereby the front surface of the wafer W is physically/chemically etched. 
   Operation of the component elements of the P/M  2 , the atmospheric transfer apparatus  3 , and the LL/M  4  constituting the substrate processing system  1  shown in  FIG. 1  is controlled in accordance with a program for implementing a substrate processing method according to the present embodiment by a computer (not shown) as a controller of the substrate processing system  1 , or by an external server (not shown) as a controller connected to the substrate processing system  1 . 
   In the P/M  2  connected to the LL/M  4  of the substrate processing system  1  described above, the stage  12  acting as the lower electrode does not move relative to the gas introducing shower head  34 ; however, the P/M connected to the LL/M  4  is not limited to this, but rather may instead be, for example, one in which the lower electrode does move relative to (approaches) the gas introducing shower head  34 . 
   Next, the substrate processing method according to the first embodiment of the present invention will be described. This substrate processing method is implemented in the atmospheric transfer apparatus  3  and the LL/M  4  of the substrate processing system  1 . 
   First, the shape of the pick  54  of the transfer arm  52  in the atmospheric transfer apparatus  3  will be described with reference to  FIGS. 3A and 3B . Note that, as described above, the shape of the pick  74  of the transfer arm  70  in the LL/M  4  is like that of the pick  54 . 
     FIG. 3A  shows a plan view in a state with a wafer W mounted on the pick  54 , and  FIG. 3B  shows an enlarged perspective view of part of the pick  54  around a tapered pad  54   a,  described below, that is provided on the pick  54 . 
   As shown in  FIG. 3A , the pick  54  has a fork shape, and has thereon four tapered pads  54   a  that support the wafer W with the wafer W separated by a predetermined gap from a surface of the pick  54 . As shown in  FIG. 3B , each of the tapered pads  54   a  has a shape comprising a truncated conical member on a cylindrical member. The four tapered pads  54   a  are disposed on the pick  54  around an outer periphery (a beveled portion) of the wafer W, each of the tapered pads  54   a  having the truncated conical portion thereof in contact with the outer periphery of the wafer W so as to prevent slipping of the wafer W relative to the pick  54 . 
   When a wafer W is transferred by the transfer arm  52  in the atmospheric transfer apparatus  3  or the transfer arm  70  in the LL/M  4 , as described above, the outer periphery of the wafer W contacts the truncated conical portion of each of the tapered pads, and hence particles become attached to the pick, in particular the tapered pads. It is thought that the attached particles are produced through wear of the tapered pads through contact friction between the outer periphery of the wafer W and the tapered pads, or through detachment of CF-type polymer attached to the outer periphery of the wafer W. When a wafer W is transferred, the particles attached to the tapered pads are then scattered toward the wafer W, causing contamination of the wafer W. 
   In the present embodiment, in the atmospheric transfer apparatus  3 , a high-temperature gas is sprayed onto the transfer arm  52  by the gas supply system  60 , whereby particles attached to the transfer arm  52 , in particular the tapered pads  54   a  of the pick  54 , are scattered away using thermal stress and thus removed. Moreover, in the LL/M  4 , high-temperature N 2  gas is sprayed onto the transfer arm  70  by the gas supply system  72 , whereby particles attached to the transfer arm  70 , in particular the tapered pads of the pick  74 , are scattered away using thermal stress and thus removed. As a result, each wafer W can be transferred without being contaminated. This will now be described in detail with reference to the drawings. 
     FIGS. 4A to 4C  are process drawings showing a method of removing particles from each tapered pad  54   a  using thermal stress. 
   As shown in  FIGS. 4A to 4C , in a state with particles attached to the pick  54  and each of the tapered pads  54   a  ( FIG. 4A ), the high-temperature gas (shown by white arrows) is sprayed onto the pick  54  and each of the tapered pads  54   a  ( FIG. 4B ), whereby the particles attached to the pick  54  and each of the tapered pads  54   a  are scattered away through thermal stress by the high-temperature gas ( FIG. 4C ). The particles attached to the pick  54  and each of the tapered pads  54   a  can thus be removed. The particles can also be removed through a similar technique for the pick  74  and the tapered pads thereon. 
   Conventionally, upon attempting to scatter away particles attached to, for example, a tapered pad by spraying with a gas, a layer where the flow velocity of the gas is zero (a boundary layer) has arisen on the surface of the tapered pad, and hence it has not been possible to spray the gas onto particles within the boundary layer, and thus it has not been possible to scatter away all of the particles. In contrast with this, in the present embodiment, the particles are scattered away using thermal stress from the high-temperature gas. Moreover, by varying the pressure of the sprayed gas, pulse waves can be produced, and hence the particles can be scattered away more effectively due to the pulse waves breaking through the above-described boundary layer. In other words, in the present embodiment, by spraying while varying the pressure of the high-temperature gas, the removal of the particles can be carried out more efficiently. 
   In the present embodiment, any gas maybe used as the high-temperature gas; oxygen gas, or a mixed gas of oxygen and other gas molecules, or ozone gas, at a high temperature may be used, so as to decompose fluorocarbon-type polymer, thus also promoting a chemical removal effect. 
   Conventionally, a wafer W is transferred into a P/M in a state with the temperature of the wafer W being low, and then plasma processing is carried out in the P/M, whereupon the wafer W is heated through heat input from the plasma, and hence the temperature of the wafer W changes. The heat input from the plasma is not stable but rather is different for each wafer W, and hence the state of temperature increase differs for each wafer W, and as a result the plasma processing results differ for each wafer W (process shift). 
   In contrast with this, in the present embodiment, the high-temperature gas is sprayed onto each wafer W in the transferring process to remove particles, and hence before the wafer W is subjected to the plasma processing, the temperature of the wafer W is increased in advance to the temperature reached through heat input from the plasma, and thus the above-described process shift can be prevented. In this case, wafer W temperature detecting means may be provided in the LL/M  4  and the atmospheric transfer apparatus  3  so that the temperature of the wafer W in the transferring process can be reliably controlled to the temperature reached through heat input from the plasma, and to shorten the heating time, the high-temperature gas may be sprayed in in the transferring process at a temperature close to the temperature reached through heat input from the plasma. Furthermore, the temperature of the wafer W may be increased to the temperature reached through heat input from the plasma by spraying in the processing gas at a high temperature from the gas introducing shower head  34  after the wafer W has been transferred into the chamber  10  of the P/M  2  but before subjecting the wafer W to the plasma processing. 
   Moreover, conventionally, if a wafer W is transferred into the chamber  10  of the P/M  2  in a state with the temperature of the wafer W being low, and the chamber  10  is evacuated, then moisture adsorbed on the wafer W is deposited as vapor onto the wafer W through the evacuation, and hence watermarks remain on the wafer W as shown in  FIG. 5 . The more residual moisture on the wafer W, the more watermarks remain after the evacuation, such watermarks readily forming defects on the wafer W. Moreover, the shape of a watermark remaining on the wafer W varies depending on the overall apparatus construction of the substrate processing system. In the present embodiment, because the high-temperature gas is sprayed onto the wafer W in the transferring process, the temperature of the wafer W is increased before the wafer W is transferred into the chamber  10  of the P/M  2 , whereby residual moisture on the wafer W can be removed, and hence watermarks can be prevented from remaining on the wafer W. Such watermarks can be removed by heating even in an atmosphere, but are more readily removed in a vacuum, and hence are preferably removed before the wafer W is transferred into the atmospheric transfer apparatus  3 . 
   Moreover, conventionally, during evacuation after maintenance on a vacuum chamber (in which the vacuum chamber is released to the atmosphere), outgassing of moisture attached to an inside wall of the chamber and so on takes place as times passes, and hence the evacuation takes a long time. In the present embodiment, the high-temperature gas is supplied into the chamber (the chamber  71  or the chamber  10 ), and hence after maintenance on the chamber, outgassing of moisture attached to the inside wall of the chamber is promoted by the high-temperature gas being supplied in, and thus the evacuation can be carried out in a short period. For a chamber for which there is almost no or very little outgassing from inside the inside wall such as a pure aluminum chamber or a ceramic thermal spraying chamber, moisture attached to the inside wall of the chamber is the main cause of outgassing. If the above technique is used with such a chamber, then the shortening of the evacuation time is very effective. The method of supplying in the high-temperature gas may be any method, but if the high-temperature gas is supplied in while carrying out the evacuation, then the outgassing of the moisture can be promoted efficiently. Moreover, to increase the reactivity with the moisture, the pressure of the high-temperature gas may be varied, or a gas having high reactivity with moisture may be mixed into the high-temperature gas. Examples of gases having high reactivity with moisture include HCl, BCl 3 , NOCl, COCl 2 , COF 2 , B 2 H 8 , Cl 2 , F 2 , SOBr 2 , dichloropropane, dimethylpropane, dibromopropane, trimethyldichlorosilane dimethyldichlorosilane, monomethyltrichlorosilane, and tetrachlorosilane. 
   Next, a substrate processing method according to a second embodiment of the present invention will be described. This substrate processing method is implemented in the P/M  2  of the substrate processing system  1 . 
   In the present embodiment, in the P/M  2 , a high-temperature gas is sprayed onto the front surface of the wafer W by the gas introducing shower head  34 , whereby particles attached to the front surface of the wafer W are scattered away using thermal stress. Moreover, a high temperature heat-transmitting gas may also be sprayed onto the rear surface of the wafer W by the heat-transmitting gas supply unit  32 , whereby particles attached to the rear surface of the wafer W may be scattered away using thermal stress. 
   Conventionally, if a wafer W is transferred out from the chamber  10  of the P/M  2  in a state with corrosive adsorbed molecules attached to the wafer W after the plasma processing, then the substrate processing system  1  may be corroded by the adsorbed molecules evaporating off from the wafer W. In the present embodiment, the wafer W is heated by spraying the high-temperature gas toward the wafer W from the gas introducing shower head  34 , which is positioned facing the front surface of the wafer W, after the plasma processing, so as to increase the temperature of the wafer W, whereby adsorbed molecules on the wafer W can be removed. Moreover, the wafer W may be heated by spraying the high-temperature heat-transmitting gas toward the wafer W from the heat-transmitting gas supply holes  30 , which face the rear surface of the wafer W, after the plasma processing, so as to increase the temperature of the wafer W, whereby adsorbed molecules on the wafer W can be removed. This will now be described in detail with reference to the drawings. 
     FIGS. 6A to 6C  are process drawings showing a method of removing adsorbed molecules on a wafer W using thermal stress. 
   As shown in  FIGS. 6A to 6C , in a state with adsorbed molecules attached to the front surface of the wafer W ( FIG. 6A ), the high-temperature gas (shown by white arrows) is sprayed onto the front surface of the wafer W ( FIG. 6B ), so as to increase the temperature of the wafer W, whereby the adsorbed molecules attached to the front surface of the wafer W are scattered away from the front surface of the wafer W through thermal stress ( FIG. 6C ). As a result, adsorbed molecules attached to the wafer W after the plasma processing can be removed. Adsorbed molecules attached to the rear surface of the wafer W can be similarly removed. 
   In the present embodiment, again, the removal of the adsorbed molecules can be carried out more efficiently by varying the pressure of the sprayed high-temperature gas so as to produce pulse waves. 
   As described earlier, if the plasma processing is carried out on the wafer W in the P/M  2  in a state with the temperature of the wafer W being low, then the plasma processing results differ for each wafer W. In contrast with this, in the present embodiment, the high-temperature gas is sprayed in from the gas introducing shower head  34  before the wafer W is subjected to the plasma processing in the chamber  10  of the P/M  2 . As a result, the temperature of the wafer W can be increased in advance to a temperature reached through heat input from the plasma, and thus the above-described process shift can be prevented. Moreover, the high temperature heat-transmitting gas may be sprayed toward the wafer W from the heat-transmitting gas supply holes  30 , which face the rear surface of the wafer W, before carrying out the plasma processing, and again, the process shift can be prevented as a result. 
   Moreover, according to the present embodiment, again, watermarks can be prevented from remaining on the wafer W, and furthermore outgassing of moisture attached to the inside wall of the chamber  10  can be promoted, and hence evacuation can be carried out in a short period. 
   It is to be understood that the object of the present invention may also be accomplished by supplying a system or apparatus with a storage medium in which is stored a program code of software that realizes the functions of an embodiment described above, and then causing a computer (or CPU, MPU, or the like) of the system or apparatus to read out and execute the program code stored in the storage medium. 
   In this case, the program code itself read out from the storage medium realizes the functions of the embodiment, and hence the program code and the storage medium in which the program code is stored constitute the present invention. 
   Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magnetic-optical disk, an optical disk such as a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, a DVD-RW or a DVD+RW, a magnetic tape, a nonvolatile memory card, and a ROM. Alternatively, the program code may be downloaded via a network. 
   Moreover, it is to be understood that the functions of the embodiment may be accomplished not only by executing a program code read out by a computer, but also by causing an OS (operating system) or the like which operates on the computer to perform a part or all of the actual operations based on instructions of the program code. 
   Furthermore, it is to be understood that the functions of the embodiment may also be accomplished by writing a program code read out from a storage medium into a memory provided on an expansion board inserted into a computer or in an expansion unit connected to the computer and then causing a CPU or the like provided on the expansion board or in the expansion unit to perform a part or all of the actual operations based on instructions of the program code. 
   The form of the program code may be an object code, a program code executed by an interpreter, script data supplied to an OS, or the like. 
   The above-described embodiments are merely exemplary of the present invention, and are not be construed to limit the scope of the present invention. 
   The scope of the present invention is defined by the scope of the appended claims, and is not limited to only the specific descriptions in this specification. Furthermore, all modifications and changes belonging to equivalents of the claims are considered to fall within the scope of the present invention.