Patent Publication Number: US-2009223443-A1

Title: Supercritical film deposition apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a supercritical film deposition apparatus, which deposits a film by supplying a source material on a substrate under a supercritical fluid ambient, and relates to a method of supercritical film deposition. 
     Priority is claimed on Japanese Patent Application No. 2008-53910, filed Mar. 4, 2008, the content of which is incorporated herein by reference. 
     2. Description of Related Art 
     Recently, in connection with down-sizing of a semiconductor device, a method of supercritical film deposition, in which a supercritical fluid is used as a medium material for film deposition, and a supercritical film deposition apparatus used for the method of supercritical film deposition have been developed (for example, refer to Japanese Unexamined Patent Application, First Application, No. 2003-213425, No. 2007-95863, No. 2007-162081, and No. 2007-250589). A supercritical condition is that temperature and pressure exceed an inherent value of a material (in other words, critical point), and the material is assumed to have both gaseous and fluid features. 
     An advantageous aspect of the method of supercritical film deposition against a conventional method of the film deposition such as a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method and the like, is often considered that a deposition rate, or a film deposition reaction rate, of the supercritical film deposition is higher than that of the conventional method. However, in view of evaluation on a throughput for the total process of the supercritical film deposition, there is a problem in that it takes a considerably long time for a preliminary process, which is necessary before and after the film deposition (for example, pressurization to exceed the critical pressure, decompression to an atmospheric pressure, heating to a film deposition temperature), as compared with the conventional method of the film deposition under a vacuum condition. 
     In the case of the film deposition under the vacuum condition, in order to enhance the throughput, a wafer is generally replaced by using a load lock system. As for the supercritical film deposition apparatus, in order to enhance the throughput, a supercritical film deposition apparatus, which employs the load lock system for replacing the wafer under a high-pressure condition, has been developed 
     However, if a load lock chamber is provided in the supercritical film deposition apparatus, which uses the supercritical fluid with a high-pressure, to employ the load lock system, there are problems described hereinbelow. 
       FIG. 9  is a horizontal cross-sectional view that shows an example of the supercritical film deposition apparatus including the load lock chamber. The supercritical film deposition apparatus includes a reactor (film deposition chamber)  32 , a transfer chamber  31 , and a load lock chamber  30 . As shown in  FIG. 9 , the transfer chamber  31  and the film deposition chamber  32  are connected by an aperture portion  3  la that passes a semiconductor wafer. A partition  33 , which isolates the transfer chamber  31  and the film deposition chamber  32  from the load lock chamber  30 , is provided between the transfer chamber  31  and the load lock chamber  30 . An outer diameter of the partition  33  is larger than an inner diameter of an aperture portion  30   a  of the load lock chamber  30 . The partition  33  is provided to cover the aperture portion  30   a  from a transfer chamber  31  side. The partition  33  can move toward the transfer chamber  31  side. A open/close mechanism  34  allows the partition  33  to open and close. As shown in  FIG. 9 , when the partition  33  is closed by the open/close mechanism  34 , the load lock chamber  30  is completely isolated from the transfer chamber  31 . 
     In the supercritical film deposition apparatus shown in  FIG. 9 , it is difficult to open and close the partition  33  when the wafer is replaced by using the load lock system under a supercritical fluid ambient with a high-pressure. For example, in the supercritical film deposition apparatus shown in  FIG. 9 , when a pressure in the load lock chamber  30  is lower than that in the transfer chamber  31 , since the partition  33  is pressed to the aperture  30   a  of the load lock chamber  30  by the pressure in the transfer chamber  31 , it is hard to move the partition  33 . On the other hand, when the pressure in the load lock chamber  30  is higher than that in the transfer chamber  31 , since the partition  33  is pushed toward a transfer chamber  31  direction, a movability of the partition  33  easily become unstable. For this reason, in the supercritical film deposition apparatus shown in  FIG. 9 , it is difficult to safely and easily open and close the partition  33 . Furthermore, since it is difficult to safely and easily open and close the partition  33 , an excess load is easily subjected to a mechanical part of the open/close mechanism  34  that supports the partition  33  and allows it to open and close. Therefore, durability of the partition  33  and the open/close mechanism  34  is insufficient in some cases. 
     In the supercritical film deposition apparatus shown in  FIG. 9 , there is a problem in that a deposition (reaction) condition in the film reposition chamber  32  is changed by thermal diffusion originated from a heat source for heating the wafer in the film deposition chamber  32 . Furthermore, there is a problem in that since a temperature variation in the entire apparatus occurs with time, degradation and damage of each component are taken place. 
     SUMMARY 
     The present invention seeks to solve one or more of the above problems, or to improve those problems at least in part 
     In one embodiment, there is provided a supercritical film deposition apparatus for depositing a film on a substrate under a supercritical fluid ambient by supplying a deposition source material, including: an autoclave that includes a reactor; a load lock chamber that is provided in the autoclave, the substrates before and after suffering depositing the film being transferred; a pressure control unit that is provided in the load lock chamber to control a pressure in the load lock chamber; an external gateway that is provided in the load lock chamber to transfer the substrate from and to outside of the autoclave; an internal gateway that is provided in the load lock chamber to transfer the substrate from and to the reactor; and a partition capable of opening and closing so as to isolate the load lock chamber from outside of the internal gateway. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above features and advantages of the present invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a horizontal cross-sectional view that shows an example of a supercritical film deposition apparatus of the present invention; 
         FIG. 2A  is a vertical cross-sectional view that shows a reactor (film deposition chamber) included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 2B  is a vertical cross-sectional view that shows the reactor (film deposition chamber) included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 3A  is a schematic diagram that shows a pipe line included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 3B  is a schematic diagram that shows the pipe line included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 4A  is a schematic diagram that shows the pipe line included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 4B  is a schematic diagram that shows the pipe line included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 5  is a vertical cross-sectional view that shows a load lock chamber and a transfer chamber included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 6  is a perspective view that shows a partition included in the supercritical film deposition apparatus shown in  FIG. 1 ; 
         FIG. 7  is a horizontal cross-sectional view that shows the supercritical film deposition apparatus, in which the partition is opened; 
         FIG. 8  is a vertical cross-sectional view that shows another example of the supercritical film deposition apparatus of the present invention; and 
         FIG. 9  is a horizontal cross-sectional view that shows an example of a supercritical film deposition apparatus including the load lock chamber. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will be described herein with reference to illustrative embodiments. Those skilled in the art will recognize that many alternative embodiments can be accomplished using the teachings of the present invention and that the invention is not limited to the embodiments illustrated here for explanatory purposes. 
     A first embodiment of a supercritical film deposition apparatus and a method of supercritical film deposition of the present invention will be described in detail hereinbelow with reference to the drawings. Although carbon dioxide (CO 2 ) is used as a specific supercritical fluid in the embodiment described below, the other supercritical fluid may be employed. For the sake of understanding a feature of the embodiment easily, there is a case that magnifies important parts for convenience in the drawings. Therefore, each component is not always shown at scale in accord with an actual case. 
       FIG. 1  is a horizontal cross-sectional view that shows an example of the supercritical film deposition apparatus of the present invention.  FIG. 2A  and  FIG. 2B  are vertical cross-sectional views that show a reactor (film deposition chamber) included in the supercritical film deposition apparatus shown in  FIG. 1 .  FIG. 3A  to  FIG. 4B  are schematic diagrams that show pipe lines included in the supercritical film deposition apparatus shown in  FIG. 1 .  FIG. 5  is a vertical cross-sectional view that shows a load lock chamber and a transfer chamber included in the supercritical film deposition apparatus shown in  FIG. 1 .  FIG. 6  is a perspective view that shows a partition included in the supercritical film deposition apparatus shown in  FIG. 1 . 
     The supercritical film deposition apparatus shown in  FIG. 1  includes an autoclave (pressure sustainable container)  40  that includes two reactors (film deposition chambers)  6   a  and  6   b,  two load lock chambers  5   a  and  5   b,  and a transfer chamber  7 . Each of the reactors  6   a  and  6   b,  the load lock chambers  5   a  and  5   b,  and the transfer chamber  7  has enough strength against high-pressure to perform the supercritical film deposition. 
     In the supercritical film deposition apparatus shown in  FIG. 1 , a wafer (substrate)  41 , which is imported from outside of the autoclave  40  into the load lock chambers  5   a  and  5   b,  is put in a front open unified pod (FOUP)  28  and transferred. The FOUP  28  is a container that stores a plurality of the wafers  41 , as shown in  FIG. 5 . Furthermore, the FOUP  28  allows each of the wafers  41  to be inserted into and ejected from each of a plurality of shelves  28   a  provided in the autoclave  40  capable of sealing. The wafer  41  stored in the FOUP  28  can be individually inserted and ejected by a robot arm  8 , when the FOUP  28  is in the load lock chambers  5   a  and  5   b,  as shown in  FIG. 5 . 
     In addition, a warm water jacket  29  is provided to cover an outer surface of the autoclave  40  of the supercritical film deposition apparatus shown in  FIG. 1 . The warm water jacket  29  controls each of the reactors  6   a  and  6   b,  the load lock chambers  5   a  and  5   b,  and the transfer chamber  7  to have a predetermined temperature. Therefore, the warm water jacket  29  is provided to contact an outer wall of each of the chambers, as shown in  FIG. 1 ,  FIG. 2 , and  FIG. 5 . In the supercritical film deposition apparatus shown in  FIG. 1 , the temperature of each chamber is controlled to exceed the critical temperature by the warm water jacket  29 . Furthermore, since the warm water jacket  29  controls the temperature of each chamber, the variation of the deposition (reaction) condition in the film reposition chambers  6   a  and  6   b,  can be effectively suppressed, and the temperature variation of an entire of the autoclave  40  with time can be effectively suppressed. Thereby, it is possible to avoid a thermal hysteresis from remaining at the outer wall of the autoclave  40 . 
     The transfer chamber  7  is provided between the reactors  6   a  and  6   b  and the load lock chambers  5   a  and  5   b.  The transfer chamber  7  is a chamber that transfers the wafer  41  between the reactors  6   a  and  6   b  and the load lock chambers  5   a  and  5   b.  The transfer chamber  7  includes the robot arm  8  that transfers the wafer  41 , as shown in  FIG. 1  and  FIG. 5 . In the supercritical film deposition apparatus shown in  FIG. 1 , the robot arm  8  transfers the wafer  41  between the reactors  6   a  and  6   b  and the load lock chambers  5   a  and  5   b  under high-pressure conditions. The transfer chamber  7  further includes feed pipe lines  1   a  and  1   b  that supply the supercritical fluid, as shown in  FIG. 1 . 
     The film deposition is performed in the reactors (film deposition chambers)  6 a and  6   b  by supplying a deposition source material on the wafer  41  under the supercritical fluid ambient.  FIG. 2A  is a schematic diagram that shows a state in which the film deposition is performed in the reactor  6   b.    FIG. 2B  is a schematic diagram that shows the state of the reactor  6   b  when the wafer  41  is replaced. While  FIG. 2A  and  FIG. 2B  show one of the reactors, or the reactor  6   b,  the other of the reactors, or the reactor  6   a,  has the same configuration. 
     As shown in  FIG. 2A  and  FIG. 2B , the reactors  6   a  and  6   b  include a transfer tunnel (transfer pathway)  42  through which the wafer  41  is transferred from the transfer chamber  7  to the reactors  6   a  and  6   b  by the robot arm  8  vice versa. The transfer tunnel  42  is formed to connect the transfer chamber  7  with the reactors  6   a  and  6   b.  The width and height of the transfer tunnel  42  are preferably as narrow and low as possible within a range in which the robot arm  8  can transfer the wafer  41 . The width and height of the transfer tunnel  42  become narrow and low, and hence, the supercritical fluid flows in one direction without convection. As a result, an outflow (bleed) of the deposition source material and the thermal diffusion from the reactors  6   a  and  6   b  to the transfer chamber  7  can be suppressed. 
     As shown in  FIG. 2A  and  FIG. 2B , the reactors (film deposition chambers)  6   a  and  6   b  include a heating table  15  that can heat the wafer  41  to a predetermined temperature for the film deposition (not shown in  FIG. 1 ). Furthermore, the reactors  6   a  and  6   b  include a pipe line system  3  that supplies the deposition source material dissolved in the supercritical fluid, and a drain pipe line  4  that ejects the deposition source material dissolved in the supercritical fluid, as shown in  FIG. 1  to  FIG. 2B . The deposition source material provided through the pipe line system  3  is supplied on the surface of the wafer  41  by ejecting via a shower head  14 , as shown in  FIG. 2A . 
     In the supercritical film deposition apparatus shown in  FIG. 1 , since the transfer chamber  7  includes the feed pipe lines  1   a  and  1   b  that supplies the supercritical fluid and the reactors  6   a  and  6   b  includes the drain pipe line  4  that ejects the supercritical fluid, the supercritical fluid flows from the transfer chamber  7  to the reactors  6   a  and  6   b.  For this reason, the outflow of the deposition source material and the thermal diffusion from the reactors  6   a  and  6   b  to the transfer chamber  7  can be effectively suppressed without providing a partition between the transfer chamber  7  and the reactors  6   a  and  6   b.  In order to suppress the outflow of the deposition source material and the thermal diffusion from the reactors  6   a  and  6   b  to the transfer chamber  7  further effectively, the supercritical fluid, which flows from the transfer chamber  7  to the reactors  6   a  and  6   b,  preferably has high purity together with low-temperature ranging from 50 to 80 degree Celsius. 
     The load lock chambers  5   a  and  5   b  import or export the wafer  41  before or after suffering the film deposition. In the supercritical film deposition apparatus shown in  FIG. 1 , the FOUP  28  storing the wafer  41  before suffering the film deposition is exchanged for the FOUP  28  storing the wafer  41  after suffering the film deposition in the load lock chambers  5   a  and  5   b.  The wafer  41  before suffering the film deposition, which is imported from the outside of the autoclave  40 , is retained in a condition (supercritical fluid), in which the pressure and temperature are higher than those of the supercritical state, in the load lock chambers  5   a  and  5   b.    
     As shown in  FIG. 1  and  FIG. 5 , the load lock chambers  5   a  and  5   b  include an external gateway  45  and an internal gateway  43 . The external gateway  45  imports and exports the wafer  41  from and to the outside of the autoclave  40 . The external gateway  45  includes an external partition  45   a  that isolates the load lock chambers  5   a  and  5   b  from the outside thereof. As shown in  FIG. 1 , when the external partition  45   a  is closed, the load lock chambers  5   a  and  5   b  are insulated from the outside of the autoclave  40 . The external partition  45   a  can move toward the outside of the autoclave  40  so as to open and close. As shown in  FIG. 1  and  FIG. 5 , the external partition  45   a  has a T-shape in the cross-sectional view, in which an outer diameter of an inner portion of the external partition  45   a  provided in the load lock chambers  5   a  and  5   b  is assumed to fit an inner diameter of the external gateway  45 , and an outer diameter of an outer portion directed to the outside of the autoclave  40  is assumed to be larger than the inner diameter of the external gateway  45 . 
     On the other hand, the wafer  41  is transferred to the reactors  6   a  and  6   b  through the internal gateway  43  vice versa. As shown in  FIG. 1  and  FIG. 5 , each internal gateway  43  of the two load lock chambers  5   a  and  5   b  is connected with the transfer chamber  7 . The internal gateway  43  includes partitions  10   a  and  10   b  that can open and close, and isolates the load lock chambers  5   a  and  5   b  from the outside thereof. As shown in  FIG. 1 , when the partitions  10   a  and  10   b  are closed, the load lock chambers  5   a  and  5   b  are insulated from the outside of the internal gateway  43 . The partitions  10   a  and  10   b  have strength against a large differential pressure (for example, about 20 MPa) that is generated when the external partition  45   a  is moved so that the load lock chambers  5   a  and  5   b  are opened. 
     The partitions  10   a  and  10   b  have a T-shape in the cross-sectional view, in which an outer diameter of an inner portion  43   c  provided in the load lock chambers  5   a  and  5   b  is assumed to fit an inner diameter of the internal gateway  43 , and an outer diameter of an outer portion  43 d directed to the outside of the load lock chambers  5   a  and  5   b  is assumed to be larger than the inner diameter of the internal gateway  43 , as shown in  FIG. 1 ,  FIG. 5 , and  FIG. 6 . While  FIG. 6  shows the partition  10   a  provided in one of the load lock chambers, or the load lock chamber  5   a,  the partition  10   b  provided in the other of the load lock chambers, or the load lock chamber  5   b,  has the same configuration. 
     As shown in  FIG. 6 , the partitions  10   a  and  10   b  have a round-shape in the plan-view. Eight pieces of fixtures  11  having a cylindrical shape, which are arranged circularly at regular intervals at the marginal position of the partitions  10   a  and  10   b,  through which one end of the fixtures  11  penetrates. As shown in  FIG. 5  and  FIG. 6 , the other end of the fixtures  11  is put in a concave portion provided at a surrounding portion  13  of the internal gateway  43 . For this reason, the partitions  10   a  and  10   b  are aligned to cover the internal gateway  43 , and the closed partitions  10   a  and  10   b  are fixed. Furthermore, a seal material  12  including an O-ring and the like is provided at a periphery (outer edge) of the inner portion  43   c  of the partitions  10   a  and  10   b,  as shown in  FIG. 6 . Thereby, the internal gateway  43  is sealed up by the partitions  10   a  and  10   b.    
     The partitions  10   a  and  10   b  include check valves  9   a  and  9   b,  as shown in  FIG. 1  and  FIG. 6 . The check valves  9   a  and  9   b  allows the supercritical fluid to flow in one direction from the load lock chambers  5   a  and  5   b  to transfer chamber  7 , as shown by arrows in  FIG. 1 . The check valves  9   a  and  9   b  are provided at six positions arranged circularly, as shown in  FIG. 6 . The number of the check valves  9   a  and  9   b  provided on the partitions  10   a  and  10   b  is not limited, and the number may be one or more. 
     The partitions  10   a  and  10   b  can move toward the transfer chamber  7  provided at the reactors  6   a  and  6   b  side, which is against the load lock chambers  5   a  and  5   b.  The partitions  10   a  and  10   b  move downwardly along a guide rail  46 , which is like a pillar and supports moving of the partitions  10   a  and  10   b,  after the partitions  10   a  and  10   b  is moved toward the transfer chamber  7  side (horizontal direction), as shown by arrows in  FIG. 5 , when the load lock chambers  5   a  and  5   b  are opened for the inside of the autoclave  40 . For this reason, when the wafer  41  is inserted to and ejected from the load lock chambers  5   a  and  5   b,  the partitions  10   a  and  10   b  can avoid contact with the wafer  41  and the robot arm  8 . 
     The load lock chambers  5   a  and  5   b  include a pressure control unit that individually controls the pressure therein. In the supercritical film deposition apparatus shown in  FIG. 1 , the pressure control unit is provided at load lock chamber feed pipe lines  1   c  and  1   d  that supply the supercritical fluid to the load lock chambers  5   a  and  5   b,  and at load lock chamber drain pipe lines  2   a  and  2   b  that eject the supercritical fluid from the load lock chambers  5   a  and  5   b.  Furthermore, the check valves  9   a  and  9   b  play a role of the pressure control unit. 
     Subsequently, a pipe line included in the supercritical film deposition apparatus shown in  FIG. 1  will be described hereinbelow with reference to  FIG. 3A  to  FIG. 4B . 
       FIG. 3A  is a schematic diagram that shows the feed pipe line  1   a  for supplying the supercritical fluid to the transfer chamber  7 . The feed pipe line  1   a  supplies the supercritical fluid to the transfer chamber  7 , the feed pipe line  1   b  supplies the supercritical fluid to the transfer chamber  7 , and the load lock chamber feed pipe lines  1   c  and  1   d  supply the supercritical fluid to the load lock chambers  5   a  and  5   b.  The above pipe lines have the same configuration except only for their setting positions. Therefore, the configuration of the feed pipe line  1   a,  which supplies the supercritical fluid to the transfer chamber  7 , is described, on behalf of the above-mentioned pipe lines. That is, the explanations of the feed pipe line  1   b  that supplies the supercritical fluid to the transfer chamber  7 , and of the load lock chamber feed pipe lines  1   c  and  1   d  that supply the supercritical fluid to the load lock chambers  5   a  and  5   b,  are omitted. 
     The feed pipe line  1   a,  which supplies the supercritical fluid to the transfer chamber  7 , provides carbon dioxide (CO 2 ) from a carbon dioxide cylinder (bottle)  20   a  as the supercritical fluid having predetermined temperature and pressure through a high-pressure valve  16   a,  carbon dioxide pump  19   a  as the pressure control unit, and a high-pressure valve  16   b  provided in a temperature control unit  18   a  including a heater and the like, as shown in  FIG. 3A . 
       FIG. 3B  is a schematic diagram that shows the load lock chamber drain pipe line  2   a  for ejecting the supercritical fluid from the load lock chamber  5   a.  The load lock chamber drain pipe line  2   a  that ejects the supercritical fluid from the load lock chamber  5   a,  and the load lock chamber drain pipe line  2   b  that ejects the supercritical fluid from the load lock chamber  5   b,  have the same configuration except only for their setting positions. Therefore, the configuration of the load lock chamber drain pipe line  2   a,  which ejects the supercritical fluid from the load lock chamber  5   a  is described, on behalf of the load lock chamber drain pipe lines. That is, the explanation of the load lock chamber drain pipe line  2   b,  which ejects the supercritical fluid from the load lock chamber  5   a,  is omitted. 
     The load lock drain pipe line  2   a,  which ejects the supercritical fluid from the load lock chamber  5   a,  ejects the supercritical fluid ejected having predetermined temperature and pressure through a high-pressure valve  16   c  provided in a temperature control unit  18   b  including the heater and the like, and a back-pressure control unit  17   a,  as shown in  FIG. 3B . 
       FIG. 4A  is a schematic diagram that shows the pipe line system  3  for supplying the deposition source material dissolved in the supercritical carbon dioxide. 
     The pipe line system  3  mixes the supercritical fluid, a reaction reagent, and a material reagent so as to provide as the reaction reagent and the material reagent dissolved in the supercritical carbon dioxide, in which: carbon dioxide is provided from a carbon dioxide cylinder (bottle)  20   b  as the supercritical fluid having predetermined temperature and pressure through a high-pressure valve  16   d,  carbon dioxide pump  19   b,  and a high-pressure valve  16   e  and a check valve  22   a  provided in a temperature control unit  18   c  including the heater and the like; the reaction reagent having a predetermined amount is provided from a reactive gas (oxygen, hydrogen, or the like) cylinder (bottle)  62  through a high-pressure valve  16   f,  a high-pressure gas mass flow  24 , and a check valve  22   b;  and the material reagent is provided from a liquid reagent (source material) stock container  26  provided in a temperature control unit  18   d  having predetermined temperature and pressure through high-pressure valves  16   g  and  16   h,  a liquid reagent pump  25 , and check valve  22   c,  as shown in  FIG. 4A . The pipe line system  3  can supply the supercritical solution that includes the deposition source material and the reaction reagent with arbitrary compositions by operating the various pumps and a mass flow controller, if necessary. 
       FIG. 4B  is a schematic diagram that shows the drain pipe line  4  for ejecting the deposition source material dissolved in the supercritical carbon dioxide. 
     The drain pipe line  4  collects the deposition source material dissolved in the supercritical carbon dioxide ejected from the reactors  6   a  and  6   b,  in which the deposition source material dissolved in the supercritical carbon dioxide is heated by a temperature control unit  18   e,  and is ejected to a separation and collection container  21  through a back-pressure control unit  17   b,  as shown in  FIG. 4B . 
     Subsequently, a method of supercritical film deposition, in which a film is deposited on the wafer  41  by using the supercritical film deposition apparatus shown in  FIG. 1 , will be described hereinbelow with reference to  FIG. 7 . 
     First of all, the FOUP  28 , which stores a plurality of the wafers  41  before suffering the film deposition, is imported to the load lock chamber  5   b  when the external partition  45   a  is opened and the partition  10   b  is closed. Then, the external partition  45   a  is closed and sealed up. 
     Then, carbon dioxide is supplied to the two reactors  6   a  and  6   b  through the pipe line system  3 , and is compressed. Carbon dioxide is supplied to the transfer chamber  7  through the feed pipe lines  1   a  and  1   b,  and is compressed. Carbon dioxide is supplied to one of the two load lock chambers, or the load lock chamber  5   b,  through the load lock chamber feed pipe line  1   d,  and is compressed. The temperature of each chamber is controlled by the warm water jacket  29  so as to allow the condition in each chamber to be under the supercritical condition (for example, the pressure of 10 MPa and the temperature of 50 degree Celsius). 
     Then, the back-pressure control unit  17   b  provided in the drain pipe line  4  controls the pressures in the reactors  6   a  and  6   b  and in the transfer chamber  7 , so that the pressures in the reactors  6   a  and  6   b  and in the transfer chamber  7  are equalized. Together with this, in order to open the partition  10   b  easily, the pressure at the reactors  6   a  and  6   b  (transfer chamber  7 ) side of the partition  10   b  and the pressure in the load lock chamber  5   b  are controlled by the back-pressure control units  17   a  and  17   b,  the load lock chamber feed pipe line  1   d,  and the check valve  9   b,  each of which is provided in the drain pipe line  4  and the load lock chamber drain pipe line  2   b.    
     Then, the partition  10   b  is opened so as to open the internal gateway  43 . Thereby, the load lock chamber  5   b  is opened for the inside of the autoclave  40 , as shown in  FIG. 7 .  FIG. 7  is a horizontal cross-sectional view that shows the supercritical film deposition apparatus shown in  FIG. 1 , in which the partition  10   b  is opened. 
     The partition  10   b  is preferably opened when the pressure at the transfer chamber  7  side of the partition  10   b  equals that in the load lock chamber  5   b.    
     The partition  10   b  may be opened when the supercritical fluid flows from the load lock chamber  5   b  to the transfer chamber  7  through the check valve  9   b,  in which a setting pressure of the back-pressure control unit  17   a  of the load lock chamber drain pipe line  2   b  is controlled to be slightly higher than that of the back-pressure control unit  17   b  of the drain pipe line  4  (the differential pressure &lt;0.2 MPa), and hence, the pressure in the load lock chamber  5   b  becomes slightly higher than the pressure at the transfer chamber  7  side of the partition  10   b  . Since the partition  10   b  includes the check valve  9   b,  even when the supercritical fluid flows from the load lock chamber  5   b  to the transfer chamber  7  through the check valve  9   b,  the differential pressure between the pressure at the transfer chamber  7  side of the partition  10   b  and the pressure in the load lock chamber  5   b  does not increase until interfering with the opening and closing of the partition  10   b.    
     Subsequently, the internal gateway  43  is opened, the robot arm  8  picks up one wafer  41  at a time from the FOUP  28  in the opened load lock chamber  5   b,  the wafer  41  is transferred to the reactor  6   a  or the reactor  6   b,  and then, the wafer  41  is put on the heating table  15  which is heated to the film deposition temperature in advance, as shown in  FIG. 7 . 
     After that, the deposition source material and the reaction reagent, which are dissolved in the supercritical carbon dioxide, are simultaneously or continuously supplied from the pipe line system  3  on the wafer  41  put on the heating table  15 . Thereby, the film deposition is started. According to the embodiments of the present invention, all of the reactors (film deposition chambers)  6   a  and  6   b,  the load lock chamber  5   b,  and the transfer chamber  7 , are assumed to be under the supercritical fluid ambient during the film deposition. Furthermore, since the supercritical fluid having, for example, a temperature of about 50 degree Celsius and a high-purity is supplied from the feed pipe lines  1   a  and  1   b  to the transfer chamber  7  and the supercritical fluid is ejected from the reactors  6   a  and  6   b  through the drain pipe line  4  during the film deposition, the outflow of the deposition source material from the reactors  6   a  and  6   b  and the thermal diffusion from the heating table  15  both to the transfer chamber  7  can be suppressed. 
     After the predetermined film is deposited on the wafer  41  as described above, the supply of the deposition source material from the pipe line system  3  is stopped. Then, the robot arm  8  exchanges the wafer  41  after suffering the film deposition for the wafer  41  before suffering the film deposition placed in the load lock chamber  5   b.    
     In the embodiments of the present invention, when the supply of the deposition source material from the pipe line system  3  is stopped, it is preferable that the feed pipe lines  1   a  and  1   b  and the pipe line system  3  keep supplying the supercritical carbon dioxide with a level of purity, the drain pipe line  4  keeps ejecting the supercritical carbon dioxide, and purging of the reactor  6   a  and  6   b  is performed. 
     Furthermore, in the embodiment of the present invention, when the film is deposited on the wafer  41  in one of the load lock chambers, or the load lock chamber  5   b,  it is preferable to perform the process described hereinbelow in the other of the load lock chambers, or the load lock chamber  5   a.    
     That is, the pressure in the other of the load lock chambers, or the load lock chamber  5   a,  is assumed to be an atmospheric pressure, the external partition  45   a  of the load lock chamber  5   a  is opened as shown in  FIG. 7 , and then, the external gateway  45  is opened so that the load lock chamber  5   a  is opened for the outside of the autoclave  40  (atmosphere opening). During the atmospheric opening, the partition  10   a  of the load lock chamber  5   a  adheres to the surrounding portion  13  of the internal gateway  43  due to the differential pressure between the atmosphere and the inside of the autoclave  40 . For this reason, pressure sealing between the inside of the autoclave  40  and the load lock chamber  5   a  can be easily and precisely achieved. 
     Subsequently, the FOUP  28 , which stores a plurality of the wafers  41  before suffering film deposition, is imported to the load lock chamber  5   a  with atmosphere opening Then, the external partition  45   a  of the load lock chamber  5   a  is closed and sealed up After that, the temperature of the load lock chamber  5   a  is controlled by the warm water jacket  29 , carbon dioxide is supplied to the load lock chamber  5   a  through the load lock chamber feed pipe line  1   c,  the atmosphere in the load lock chamber  5   a  is exhausted, and the carbon dioxide is compressed. Thereby, the load lock chamber  5   a  is assumed to be under the supercritical condition, as is the case with the load lock chamber  5   b,  the reactors  6   a  and  6   b,  and the transfer chamber  7 . 
     Thereafter, when the film deposition on all the wafers  41  in the load lock chamber  5   b  is completed, the partition  10   a  is opened and the load lock chamber  5   a  is opened for the inside of the autoclave  40  as is the case with the partition  10   b,  and then, the film deposition on the wafer  41  in the load lock chamber  5   a  is performed, similar to the wafer  41  in the load lock chamber  5   b.    
     Then, the partition  10   b  of the load lock chamber  5   b,  to which the wafer  41  after suffering the film deposition is transferred, is closed so as to close the internal gateway  43 . At this time, it is preferable that the pressure at the transfer chamber  7  side of the partition  10   b  and the pressure in the load lock chamber  5   b  are equalized. 
     As described above, after the partition  10   b  of the load lock chamber  5   b,  the load lock chamber  5   b  is decompressed to an atmospheric pressure by ejecting carbon dioxide from the load lock chamber  5   b,  the external partition  45   a  of the load lock chamber  5   b  is opened so as to open the external gateway  45 , and then, the load lock chamber  5   b  is opened for the outside of the autoclave  40  (atmosphere opening). After that, the FOUP  28 , which stores the wafer  41  after suffering the film deposition, is exported, and then, the FOUP  28 , which stores a plurality of the wafers  41  before suffering the film deposition, is imported. 
     Hereinafter, as is the case described above, the external partition  45   a  of the one of the load lock chambers  5   a  and  5   b  is opened so as to open the external gateway  45 , the load lock chamber  5   b  is opened for the outside of the autoclave  40  (atmosphere opening), the partition  10   b  of the other of the load lock chambers  5   a  and  5   b  is opened so as to open the internal gateway  43 , and then, the load lock chamber  5   b  is opened for the inside of the autoclave  40 . After that, exchanging the wafer  41  after suffering the film deposition for the wafer  41  before suffering the film deposition in one of the load lock chambers, and the film deposition on the wafer  41  imported to the other of the load lock chambers, are simultaneously performed. Thereby, the film is deposited on all the wafers  41  before suffering the film deposition. 
     In the supercritical film deposition apparatus shown in  FIG. 1 , the internal gateway  43  of the load lock chambers  5   a  and  5   b  includes the partitions  10   a  and  10   b  capable of opening and closing so as to isolate the load lock chambers  5   a  and  5   b  from the outside of the internal gateway  43 . Since the load lock chamber feed pipe lines  1   c  and  1   d,  the load lock chamber drain pipe lines  2   a  and  2   b,  and the check valves  9   a  and  9   b  include the pressure control unit in the load lock chambers  5   a  and  5   b,  the pressure in the load lock chambers  5   a  and  5   b  can be controlled by these pressure control units. Thereby, the partitions  10   a  and  10   b  can be easily opened and closed. 
     For example, the pressure at the transfer chamber  7  side of the partitions  10   a  and  10   b  and the pressure in the load lock chambers  5   a  and  5   b  are controlled to be the same. Alternately the pressure in the load lock chambers  5   a  and  5   b  is controlled to flow the supercritical fluid from the load lock chamber  5   b  to the transfer chamber  7  through the check valve  9   a  and  9   b.  Thereby, the partitions  10   a  and  10   b  can be easily opened and closed. For this reason, an excess load is not easily subjected to the partitions  10   a  and  10   b,  the guide rail  46  that supports the partitions  10   a  and  10   b,  the fixture  11  that opens and closes the partitions  10   a  and  10   b,  and the like. Therefore, durability of the supercritical film deposition apparatus can be enhanced. 
     The supercritical film deposition apparatus shown in  FIG. 1  further includes the pressure control unit that controls the pressure in the load lock chambers  5   a  and  5   b,  in addition to the partitions  10   a  and  10   b.  Therefore, even when the reactors  6   a  and  6   b  and the transfer chamber  7  are in the high-pressure condition, while only the load lock chambers  5   a  and  5   b  are assumed to be under the atmospheric pressure condition by closing the partitions  10   a  and  10   b,  the wafer  41  in the load lock chambers  5   a  and  5   b  can be imported and exported. 
     Therefore, according to the supercritical film deposition apparatus shown in  FIG. 1 , there is no necessity to take a time for each of pressurization of the reactors  6   a  and  6   b,  decompression, and heating the wafer  41 , which are limiting factors in the supercritical film deposition. For this reason, the film deposition on the wafer  41  can be performed by sequentially exchanging the wafer  41  after suffering the film deposition in the reactors  6   a  and  6   b.  Therefore, according to the supercritical film deposition apparatus shown in  FIG. 1 , a throughput of the method of supercritical film deposition can be drastically improved. 
     Alternately, according to the supercritical film deposition apparatus shown in  FIG. 1 , there is no necessity to allow the reactors  6   a  and  6   b  to open for atmosphere whenever the film deposition on one wafer  41  is completed. For this reason, it is possible to remarkably reduce the number of occasions at which the reactors  6   a  and  6   b  are exposed to contaminants in air, as compared to the case in which atmosphere opening is carried out whenever the film deposition on one wafer  41  is completed. Accordingly, a high-quality film can be obtained while maintaining reproducibility. 
     In the supercritical film deposition apparatus shown in  FIG. 1 , the transfer chamber  7  is provided between the reactors  6   a  and  6   b  and the load lock chambers  5   a  and  5   b,  the feed pipe lines  1   a  and  1   b,  which supply the supercritical fluid, is provided in the transfer chamber  7 , the drain pipe line  4 , which ejects the supercritical fluid, is provided in the reactors  6   a  and  6   b,  the supercritical fluid flows from the transfer chamber  7  to the reactors  6   a  and  6   b.  As a result, the diffusion of the heat and the deposition source material from the reactors  6   a  and  6   b  to the transfer chamber  7  can be effectively suppressed. Accordingly, the variation of the deposition condition in the reactors  6   a  and  6   b  can be effectively suppressed, and the temperature variation of the entire of the supercritical film deposition apparatus with time can be further effectively suppressed. 
     According to the supercritical film deposition apparatus shown in  FIG. 1 , the internal gateway  43  of the two load lock chambers  5   a  and  5   b  is connected with the transfer chamber  7 . When the external gateway  45  of one of the load lock chambers is opened, the internal gateway  43  of the other of the load lock chambers is opened. Therefore, exchanging the wafer  41  after suffering the film deposition for the wafer  41  before suffering the film deposition in one of the load lock chambers, and the film deposition on the wafer  41  in the other of the load lock chambers, can be simultaneously performed. In this case, a time except for the film deposition is minimized (for example, pressurization to exceed the critical pressure in the autoclave  40 , decompression to an atmospheric pressure in the load lock chambers  5   a  and  5   b,  heating to a film deposition temperature in the autoclave  40 ), so as to enable effective performance of the film deposition on the wafer  41  sequentially. 
     In addition, in the supercritical film deposition apparatus shown in  FIG. 1 , since the pressure control unit, which individually controls the pressures in the load lock chambers  5   a  and  5   b,  is provided, when exchanging the wafer  41  after suffering the film deposition for the wafer  41  before suffering the film deposition in one of the load lock chambers, and the film deposition on the wafer  41  in the other of the load lock chambers, are simultaneously performed, the pressures in the load lock chambers  5   a  and  5   b  can be easily and individually controlled. Therefore, the film deposition can be safely and constantly performed using the load lock system. 
     Furthermore, in the supercritical film deposition apparatus shown in  FIG. 1 , since the pressure control unit controls the pressure in the load lock chambers  5   a  and  5   b,  the pressure at the transfer chamber  7  side of the partitions  10   a  and  10   b  and the pressure in the load lock chambers  5   a  and  5   b  are controlled to be the same. Alternately the pressure in the load lock chambers  5   a  and  5   b  is controlled so that the supercritical fluid flows from the load lock chamber  5   b  to the transfer chamber  7  through the check valve  9   a  and  9   b.  Thereby, the partitions  10   a  and  10   b  can be easily opened and closed. 
     Subsequently, a second embodiment of a supercritical film deposition apparatus and a method of supercritical film deposition of the present invention will be described in detail hereinbelow with reference to the drawings.  FIG. 8  is a vertical cross-sectional view that shows another example of the supercritical film deposition apparatus of the present invention. In the supercritical film deposition apparatus according to the second embodiment, although the reactor (film deposition chamber) is different from the supercritical film deposition apparatus shown in  FIG. 1 , the other components are the same. Therefore, the explanation of the same configuration as the supercritical film deposition apparatus shown in  FIG. 1  is omitted or simplified for the supercritical film deposition apparatus of the second embodiment shown in  FIG. 8 . 
     The reactors  6   a  and  6   b  included in the supercritical film deposition apparatus shown in  FIG. 1  is the so-called piece-to-piece system. On the other hand, a reactor  61  included in the supercritical film deposition apparatus shown in  FIG. 8  is a batch system that can simultaneously deposit films on a plurality of the wafers  41 . As shown in  FIG. 8 , the batch type reactor  61  includes a plurality of heating tables  30  which are separated from each other and are arranged along the vertical direction (for example,  25  heating tables are shown). In order to suppress undesirable deposition on a back surface of the heating table  30 , a thermal barrier layer made of a thermal insulator may be provided on the back surface of the heating table  30 . Each wafer  41  is put on a heat zone of each heating table  30 , and the film is deposited on the wafer  41 . 
     Subsequently, the method of supercritical film deposition, which deposits films on the wafer  41  using the supercritical film deposition apparatus shown in  FIG. 8 , will be described hereinbelow. 
     When the supercritical film deposition apparatus shown in  FIG. 8  is used, as is the case with the supercritical film deposition apparatus shown in  FIG. 1 , the load lock chamber  5   b  is opened, the robot arm  8  picks up wafer  41  one by one from the FOUP  28  in the load lock chamber  5   b,  the wafer  41  is transferred to the reactor  61 , the wafer  41  is put on the heating table  30  which is heated to the film deposition temperature in advance, and then, the film is deposited on the wafer  41 . As is different from the case with the supercritical film deposition apparatus shown in  FIG. 1 , the films are simultaneously deposited on a plurality of the wafers  41  by using the supercritical film deposition apparatus shown in  FIGS. 8 . The robot arm  8  exchanges the wafer  41  after suffering the film deposition for the wafer  41  before suffering the film deposition in the load lock chamber  5   b.    
     Since the supercritical film deposition apparatus including the batch type reactor  61  can simultaneously deposit the films on a plurality of the wafers  41 , it is possible to enhance the throughput rather than that of the supercritical film deposition apparatus including the piece-to-piece type reactors  6   a  and  6   b  shown in  FIG. 1 . However, in light of the uniformity in a whole wafer or in a lot, the piece-to-piece type reactors  6   a  and  6   b  are superior to the batch type reactor  61 . Accordingly, it is necessary only to decide which type of the reactors, the piece-to-piece type reactors  6   a  and  6   b  or the batch type reactor  61 , is employed by considering the characteristic and throughput desired to the film. 
     In the supercritical film deposition apparatus shown in  FIG. 8 , the internal gateway  43  of the load lock chambers  5   a  and  5   b  includes the partitions  10   a  and  10   b  capable of opening and closing so as to isolate the load lock chamber  5   a  and  5   b  from the outside of the internal gateway  43 . Since the load lock chamber feed pipe lines  1   c  and  1   d,  the load lock chamber drain pipe lines  2   a  and  2   b,  and the check valves  9   a  and  9   b  include the pressure control unit in the load lock chambers  5   a  and  5   b,  the pressure in the load lock chambers  5   a  and  5   b  can be controlled by these pressure control units. Thereby, the partitions  10   a  and  10   b  can be easily opened and closed. 
     The present invention is not limited to the above embodiments. For example, the chamber number of the reactor and the load lock chamber is not limited two. The chamber number may be one, or three or more, and the number can be determined by consideration of productivity, the film deposition condition, and the like. It is preferable that all of the load lock chamber feed pipe line, the load lock chamber drain pipe line, and the check valve, have the pressure control unit, and are interacted with each other, since the pressure in the load lock chamber can be easily and precisely controlled. However, if the pressure in the load lock chamber can be controlled, any configuration may be employed. For example, only the load lock chamber feed pipe line or a set of the load lock chamber feed pipe line and the check valve may be employed. 
     According to the supercritical film deposition apparatus of the present invention, the load lock chamber includes the pressure control unit that controls the pressure therein, the external gateway that imports and exports the wafer from and to the outside of the autoclave, the internal gateway that transfers the wafer to and from the reactor, wherein the internal gateway includes the partition that enables to open and close so as to isolate the load lock chamber from the outside of the internal gateway. Thereby, the pressure control unit controls the pressure in the load lock chamber so as to enable to easily open and close the partition. As a result, the partition can be easily opened and closed. For this reason, the excess load is not easily subjected to the partition, the components that support, open and close the partition. Therefore, durability of the partition, the components that support, open and close the partition can be enhanced. 
     According to the supercritical film deposition apparatus of the present invention, the transfer chamber is provided between the reactor and the load lock chamber, the feed pipe line, which supplies the supercritical fluid, is provided in the transfer chamber, the drain pipe line, which ejects the supercritical fluid, is provided in the reactor. When the supercritical fluid flows from the transfer chamber to the reactor, the diffusion of the heat and the deposition source material from the reactor to the transfer chamber can be effectively suppressed. Therefore, the temperature variation of the entire apparatus with time can be suppressed. As a result, the degradation and damage of each component by the temperature variation with time can be prevented. 
     According to the method of supercritical film deposition of the present invention, the film deposition on the substrate is performed by using the supercritical film deposition apparatus of the present invention. In the method of supercritical film deposition, since the pressure control unit controls the pressure in the load lock chamber, the partition can be easily opened and closed by controlling the pressure in the load lock chamber. 
     It is apparent that the present invention is not limited to the above embodiments, but may be modified and changed without departing from the scope and spirit of the invention. 
     Alternately, although the invention has been described above in connection with several preferred embodiments thereof, it will be appreciated by those skilled in the art in that those embodiments are provided solely for illustrating the invention, and should not be relied upon to construe the appended claims in a limiting sense.