Abstract:
A gas reaction system is disclosed which comprises a vaporizer ( 230 ) for generating a reaction gas by vaporizing a liquid material and a reaction chamber ( 221 A) wherein the reaction gas is reacted. The vaporizer ( 230 ) is integrally formed with a component member which defines the reaction chamber ( 221 A). The reaction gas generated in the vaporizer ( 230 ) is directly introduced into the reaction chamber ( 221 A). The vaporization chamber ( 232 ) of the vaporizer ( 230 ) is a space between an upper plate ( 230 A) and a cap ( 230 B) attached to the upper surface of the upper plate ( 230 A). A narrow passage ( 233 ) is formed between the cap ( 230 B) and the upper plate ( 230 A) which passage ( 233 ) communicates with the vaporization chamber ( 232 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a gas reaction apparatus and a semiconductor processing apparatus; more particularly, to a gas reaction apparatus and a semiconductor processing apparatus having a vaporization unit for vaporizing a liquid source material to produce a reaction gas or a processing gas. The term “semiconductor processing” used herein implies various processes to manufacture semiconductor devices and/or a structure including wiring, electrodes, and the like connected to the semiconductor devices on a substrate to be processed, by forming a semiconductor layer, an insulating layer, a conductor layer and the like, in a predetermined pattern, on the substrate to be processed, e.g., a semiconductor wafer or a glass substrate for LCD (Liquid Crystal Display) or FPD (Flat Panel Display).  
       BACKGROUND OF THE INVENTION  
       [0002]     Generally, in a fabrication line of a semiconductor, a liquid crystal display or the like, a gas reaction apparatus for performing various processes by introducing a source gas into a reaction chamber is utilized. For example, as for a film forming apparatus for forming an insulation thin film on a surface of a substrate to be processed such as a semiconductor wafer or the like, a chemical vapor deposition apparatus (CVD apparatus) for performing a film formation by a gas reaction has been known. Recently, the CVD apparatus is used for forming a multi-component metal oxide thin film such as PZT (lead zirconate titanate).  
         [0003]     Generally, since an organic metal compound, which is a source material of a thin film such as PZT or the like, is solid at room temperature under atmospheric pressure, it is necessary to gasify this kind of a solid source material to supply it into a processing chamber to be used in the CVD apparatus. In this case, the solid source material is dissolved into a liquid by using a proper solvent (referred to as a solution source), and vaporized in a vaporizer to be supplied into the processing chamber. Such a source supply method is referred to as a solution vaporizing method. The solution vaporizing method has been actively studied and developed as a promising gasifying method capable of substituting a bubbling method or a solid sublimation method (e.g., see Japanese Patent Laid-open Application No. 7-94426).  
         [0004]     Here, an example of forming a ternary metal oxide thin film by the solution vaporizing method will now be discussed.  FIG. 10  is a schematic diagram showing an entire conventional gas reaction apparatus (film forming apparatus). As shown in  FIG. 10 , in a film forming apparatus  100 , source material solutions, which are different from each other, are stored in source vessels divided into plural systems, respectively. For example, these source vessels are formed of a source vessel  101   a  for storing a lead based source material solution; a source vessel  101   b  for storing a zirconium based source material solution; and a source vessel  101   c  for storing a titanium based source material solution.  
         [0005]     The source material solutions are respectively extracted into supply lines  103   a ,  103   b  and  103   c  to be flown through a main line  107  via respective flow rate controllers  105   a ,  105   b  and  105   c  by a pressurized gas A supplied through a force feed gas line  102 . A carrier gas B such as a nonreactive gas (e.g., He, Ar or the like) or the like is supplied into the main line  107  through a flow rate controller  115 . The source material solutions are mixed with the carrier gas in the main line  107 , and thus transferred to a vaporizer  110  in a gas-liquid mixed state. Further, there is prepared a solvent vessel  101   d  for accommodating therein a solvent, e.g., butyl acetate, octane or THF (tetrahydrofuran). In the same manner, the solvent accommodated in the solvent vessel  101   d  is extracted to the supply line  104  by the pressurized gas A to be flown into the main line  107  through a flow rate controller  106 .  
         [0006]     A nozzle  111  is disposed at the vaporizer  110 , to which the main line  107  is connected. Further, a carrier gas C is supplied to the nozzle  111  through a line  108  via a flow rate controller  109 . At the nozzle  111 , there is provided a nozzle port of a double tube structure. For example, the solution source materials supplied into an inner tube are sprayed into a vaporizing chamber  112  by the carrier gas C supplied into an outer tube. Here, a nozzle part is cooled below a room temperature to prevent the solvent having a low vaporization temperature from being vaporized first since a vaporization temperature of the solvent to be used is different from that of the source material itself, generally.  
         [0007]     An inner surface of the vaporizer  112  corresponds to a vaporizing surface  112   a  for vaporizing the source material, and is heated to about, e.g., 200° C. Misty solution source materials ejected from the nozzle  111  collide with the vaporizing surface  112   a  to be vaporized instantaneously to become a source gas in the vaporizing chamber  112 . The source gas is drained from a gas draining port  113  through a filter  114  to be supplied into a processing chamber  121  of a film forming apparatus main body  120  through a gas transporting line  116 . The gas transporting line  116  is heated such that the source gas passing therethrough is not solidified or liquefied.  
         [0008]     In the processing chamber  121 , there are disposed a showerhead  122  to which the gas transporting line  116  is connected; and a susceptor  123  for mounting thereon a substrate W to be processed. An oxidizing gas, such as O 2 , N 2 O, NO 2  or the like, which reacts with the source gas in the processing chamber  121 , is supplied into the showerhead  122  through a reaction gas supply line  117 . In the processing chamber  121 , a thin film is formed on the substrate to be processed W by reactions between the source gas and the oxidizing gas.  
         [0009]     However, in the conventional film forming apparatus  100 , the gas transporting line  116  between the vaporizer  110  and the processing chamber  121  is long so that particles are likely to be produced in the source gas, or a supply amount of source gas is fluctuated, thereby deteriorating the uniformity in a film composition or a film thickness.  
         [0010]     Further, an inside of the entire gas transporting line  116  must be heated to a temperature higher than a vaporization temperature of the source and at the same time lower than a decomposition temperature thereof, such that the source gas is not solidified or liquefied during the transportation. In this case, since a heating unit and a temperature control unit are required, the overall structure gets complicated. Moreover, the vaporizer  110 , the gas transporting line  116  and the processing chamber  121  need to be heated individually, resulting in an increase of power consumption. In addition, the vaporizer  110  and the gas transporting line  116  need to be equipped with a heating unit, so that the entire apparatus becomes large-scaled.  
       SUMMARY OF THE INVENTION  
       [0011]     It is, therefore, an object of the present invention to provide a gas reaction apparatus and a semiconductor processing apparatus, wherein a high quality gas reaction can be realized and the apparatus can be made simple and small by preventing particles from being produced during the transportation of the source gas.  
         [0012]     In accordance with a first aspect of the present invention, there is provided a gas reaction apparatus including: a vaporizer for producing a reaction gas by vaporizing a liquid source material; and a reaction chamber in which the reaction gas reacts, wherein the vaporizer is integrally formed with constituent members forming the reaction chamber, and the reaction gas produced in the vaporizer is directly introduced into the reaction chamber.  
         [0013]     In accordance with the gas reaction apparatus of a first aspect, it is unnecessary to prepare a gas transporting line between the vaporizer and the reaction chamber, and to prepare a heating unit for heating the gas transporting line. Further, the transfer distance of the reaction gas becomes shortened to reduce the residence time thereof during the transportation, and thus it is possible to prevent particles being produced during the transportation.  
         [0014]     The clause “the reaction gas produced in the vaporizer is directly introduced into the reaction chamber” used herein excludes such a case that the reaction gas is introduced into the reaction chamber after passing through a line at the outside of structure parts forming the vaporizer and the reaction chamber.  
         [0015]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that the vaporizer is directly formed at an outer side of a gas introduction unit for introducing the reaction gas into the reaction chamber. The reaction gas produced in the vaporizer is directly introduced into the gas introduction unit disposed at the inner side thereof, so that the path towards the reaction chamber can be further shortened. Therefore, particles can be further reduced, and stability of the reaction gas can be improved. Here, in the gas introduction unit, there are disposed gas inlet openings, opened towards the reaction chamber, for introducing the reaction gas. For example, the gas introduction unit may have a showerhead structure having plural gas inlet openings.  
         [0016]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that the vaporizer is formed above the reaction chamber. By this, disassembling operation (maintenance work) of the vaporizer or the gas introduction unit can be readily carried out.  
         [0017]     Further, as an entire configuration, it is preferable that the vaporizer and the gas introduction unit are formed as a unit, and the vaporizer as well as the gas introduction unit is configured to be separated from other parts of the structural parts forming the reaction chamber, i.e., configured to be opened or closed.  
         [0018]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that the vaporizer contains a spraying nozzle; a vaporizing chamber forming a spraying space of corresponding spraying nozzle; a narrow passageway communicating with corresponding vaporizing chamber; and a draining unit communicating with corresponding narrow passageway and the reaction chamber. In this case, the liquid source material is sprayed into the vaporizing chamber by the spraying nozzle to be vaporized therein, and thus producing the reaction gas. After that, the reaction gas reaches to a draining unit through the narrow passageway, and is introduced into the reaction chamber therefrom. At this time, since the reaction gas produced in the vaporizing chamber passes through the narrow passageway before being introduced into the reaction chamber, the fine mist contained in the source gas is captured in the inner surface of the passageway to thereby be re-vaporized easily. As a result, vaporization efficiency of the reaction gas can be further increased, and at the same time, particles to be introduced into the reaction chamber can be further reduced.  
         [0019]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that the narrow passageway is formed of one or more passageways annularly disposed around the vaporizing chamber, and an annular draining passage communicating with the narrow passageway is disposed in the draining unit. In this way, the vaporizer can be made thin. Further, sufficient flow path cross sectional area of the narrow passageway can be obtained without making the apparatus large. Still further, the annular draining passage communicating with the narrow passageway is disposed, so that sufficient conductance of the reaction gas passing through the narrow passageway can be secured. Thus, a residing part of the gas is hardly generated in the introduction passage of the reaction gas to the reaction chamber, so that particles to be introduced into the reaction chamber can be further reduced. Here, it is preferable that the annular draining passage is disposed around the narrow passageway to make the vaporizer smaller, and coaxially configured with the narrow passageway.  
         [0020]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that a heater unit for heating inner surfaces of the vaporizing chamber and the narrow passageway is further included. In this way, vaporization action can be obtained in the inner surface of the vaporizing chamber, and the mist can be also vaporized in the inner surface of the narrow passageway. Therefore, vaporization efficiency of the reaction gas can be increased, and at the same time, particles can be reduced. Here, in case where the vaporizer is directly formed at the outer side of the gas introduction unit, the gas introduction unit may be simultaneously heated by the heater unit, as well.  
         [0021]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that a filter for capturing solid or liquid phase materials in the reaction gas is disposed inside the draining passage. Since solid or liquid phase materials in the reaction gas can be captured by the filter, particles to be introduced into the reaction chamber can be further reduced. Further, since the filter is disposed inside the draining passage, sufficient filter area can be secured. Still further, since the filter is disposed at a downstream side of the narrow passageway having capture capability of the mist, the filter can be prevented from being clogged.  
         [0022]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that the filter is disposed at a draining port of the draining passage, which communicates with the reaction chamber. In this way, the space for installing the filter is minimally restricted, so that solid or liquid phase materials in the reaction gas can be securely captured.  
         [0023]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that a valve body for opening or closing the draining port is disposed, and the filter is disposed to surround the valve body. By this, the draining port can be opened or closed by the valve body. Further, since the filter is disposed to surround the valve body, the filter can be accommodated in the space where the valve body is accommodated, and thus the vaporizer can be formed more compactly.  
         [0024]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that a heater unit for heating the filter is included. By this, the mist captured by the filter is vaporized, so that vaporization efficiency can be enhanced, and at the same time, the filter can be prevented from being clogged.  
         [0025]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that the filter makes a thermal contact with an inner surface of the draining passage, and heated by the heater through the inner surface of the draining passage. In this way, since the heater unit can be disposed at the outer side of the draining passage, degree of freedom for placing the heater can be increased, and at the same time, the draining passage can be made compact. The heater may be in common with the heater for heating the vaporizing chamber.  
         [0026]     In the gas reaction apparatus in accordance with the first aspect, it is preferable that a heat transfer unit, thermally contacted with a portion other than edges of the filter, is disposed at the draining passage. By this, the filter can be more uniformly heated, so that vaporization efficiency can be increased, and at the same time, local clogging of the filter can be reduced. As for the heat transfer unit, there may be used, e.g., a protrusion protruded from the inner surface of the draining passage to be contacted with the filter surface.  
         [0027]     In accordance with a second aspect of the present invention, there is provided a semiconductor processing apparatus, including: a vessel forming a processing chamber for processing a substrate to be processed, the vessel having a upper plate capable of being attached thereto and detached therefrom; a supporting member, disposed inside the vessel, for supporting the substrate to be processed; a showerhead for supplying a processing gas into the processing chamber, the showerhead being disposed below the upper plate to face the substrate supported by the supporting member; a vaporizing chamber, disposed on the upper plate, for producing the processing gas by vaporizing a liquid source material; and a gas passage, configured to connect the vaporizing chamber with the showerhead through the upper plate, for flowing the processing gas. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]      FIG. 1  offers a schematic vertical cross sectional view for showing a main body of a gas reaction apparatus (semiconductor processing apparatus) in accordance with a preferred embodiment of the present invention.  
         [0029]      FIG. 2  shows a magnified cross sectional view showing one portion of a vaporizer in the main body described in  FIG. 1   
         [0030]      FIG. 3  explains a magnified cross sectional view showing one portion of a modified exemplary vaporizer described in  FIG. 2 .  
         [0031]      FIG. 4  sets forth a magnified cross sectional view showing one portion of an additional modified exemplary vaporizer described in  FIG. 2 .  
         [0032]      FIGS. 5A and 5B  are of a vertical side view and a vertical front view, respectively, for schematically showing a spraying nozzle that may be used in the vaporizers described in FIGS.  2  to  4 .  
         [0033]      FIGS. 6A  to  6 D provide cross sectional views taken along the lines VIA, VIB, VIC and VID of  FIG. 5A , respectively.  
         [0034]      FIGS. 7A and 7B  are of a vertical side view and a vertical front view, respectively, for schematically showing another spraying nozzle that may be used in the vaporizers described in FIGS.  2  to  4 .  
         [0035]      FIGS. 8A  to  8 E show cross sectional views taken along the lines VIIIA, VIIIB, VIIIC, VIIID and VIIIE of  FIG. 5A , respectively.  
         [0036]      FIG. 9  is a vertical front view for schematically showing still another spraying nozzle that may be used in the vaporizers described in FIGS.  2  to  4 .  
         [0037]      FIG. 10  offers a schematic diagram for showing an entire configuration of a conventional gas reaction apparatus (film forming apparatus). 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]     Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Further, parts having substantially same functions and configurations are designated by same reference numerals, and their redundant explanations will be omitted unless necessary.  
         [0039]     A gas reaction apparatus (semiconductor processing apparatus) in accordance with an embodiment explained hereinafter is formed as a film forming apparatus (CVD apparatus) for performing a film formation on a substrate to be processed W in a reaction chamber. However, the present invention may be applied to other gas reaction apparatus (semiconductor processing apparatus), e.g., a dry etching apparatus, a plasma ashing apparatus or the like, having a vaporizing unit for producing a reaction gas or a processing gas by vaporizing a liquid source material.  
         [0040]      FIG. 1  presents a schematic vertical cross sectional view for showing a main body of a gas reaction apparatus (semiconductor processing apparatus) in accordance with a preferred embodiment of the present invention. As shown in  FIG. 1 , a film forming apparatus main body  220  includes a vessel casing  221  whose upper portion is opened. A gas introduction unit (showerhead)  222  is disposed at the upper portion of the vessel casing  221 . A susceptor (substrate holder)  223  is arranged in the vessel casing  221 . Here, a reaction chamber (processing chamber)  221 A is formed in a space between the gas introduction unit  222  and the susceptor  223 . An exhaust system (ES) is connected to the vessel casing  221  through an exhaust space  221 o. The reaction chamber  221 A is exhausted by the exhaust system (ES) to be depressurized.  
         [0041]     The susceptor  223  is supported by a ring shaped supporting body  224  made of, e.g., AlN, Al 2 O 3 , quartz or aluminum. On the supporting body  224 , there is disposed a shield ring  225  made of quarts or the like. The supporting body  224  is supported by a shield base  225   b  through an attachment  225   a . A circular flow rectifying plate  225   c  is fitted to an outer periphery of the shield base  225   b . The reaction chamber  221 A communicates with the exhaust space  221   o  through the flow rectifying plate  225   c.    
         [0042]     A window member  226  made of quartz or the like is furnished under the susceptor  223 . Heating lamps  227  are disposed outside (below) the window member  226 . Light from the heating lamps  27  is irradiated to a lower surface of the susceptor  223  through the window member  226  to heat the susceptor  223 . An annular reflector  228  for reflecting light irradiated from the heating lamps  227  is disposed between the susceptor  223  and the window member  226 . A temperature sensor such as a thermocouple is introduced into the susceptor  223  from the outside. A ceramic heater, which is made of Al 2 O 3 , AlN, SiC and the like and formed by embedding a resistor in the susceptor  223 , can be used as the heat source.  
         [0043]     In the vessel casing  221 , a loading port  221   i  is configured to be opened or closed by a gate valve  221 X. A lift mechanism (not shown) is disposed in the vessel casing  221 , and multiple lifter pins can be popped out from or popped into the susceptor  223  by the lift mechanism.  
         [0044]     The substrate to be processed (e.g., semiconductor wafer or the like) W is loaded into the vessel casing  221  through the loading port  221   i  by a transfer unit (not shown), when performing a film forming processing on the substrate to be processed. The loaded substrate W is supported by the lifter pins of the lift mechanism protruded from the susceptor  223 . Subsequently, the lifter pins are popped into the susceptor  223 , so that the substrate to be processed W is mounted on the susceptor  223 . When the film forming processing on the substrate to be processed W is completed, the lifter pins of the lift mechanism are popped out to lift the substrate to be processed W upward from the susceptor  223 . Then, the substrate to be processed W is supported by the transfer unit and unloaded to the outside through the loading port  221   i.    
         [0045]     An upper opening of the vessel casing  221  is airtightly closed with an upper plate  230 A. The gas introduction unit (showerhead)  222  is integrally placed on a lower surface of the upper plate  230 A. On the lower surface of the upper plate  230 A, there are placed a middle plate  222 A and a lower plate  222 B to form the showerhead  222 . A source gas diffusion space  222   a  is formed between the middle plate  222 B and the upper plate  230 A. From the source gas diffusion space  222   a , there are extended plural source gas supply paths  222   ax  communicating with the reaction chamber  221 A through the middle  222 A and the lower plate  222 B.  
         [0046]     A reaction gas diffusion space  222   b  is formed between the middle plate  222 A and the lower plate  222 B. From the reaction gas diffusion space  222   b , there are extended plural reaction gas supply paths  222   bx  communicating with the reaction chamber  221 A through the lower plate  222 B. The reaction gas diffusion space  222   b  is connected to a reaction gas supply unit (RGS) through a reaction gas supply line  222 S extending from the top surface of the upper plate  230 A. From the reaction gas supply unit (RGS), there is introduced a reaction gas (e.g., an oxidizing gas such as O 2 , N 2 O, NO 2  or the like) into the reaction gas diffusion space  222   b.    
         [0047]     A vaporizer  230  is disposed on the upper plate  230 A, i.e., above the gas introduction unit  222 . On the top surface of the upper plate  230 A, there is formed a protrusion  232 S defining a sidewall of the vaporizing chamber  232  to form a vaporizing chamber  232  of the vaporizer  230 . Namely, a recess of the vaporizing chamber  232  is formed on the top surface of the upper plate  230 A by the protrusion  232 S. On the upper plate  230 A, there is disposed a cap  230 B, which can be airtightly attached thereto or detached therefrom, to cover the protrusion  232 S. The vaporizing chamber  232  is formed as a space surrounded by the protrusion  232 S between the upper plate  230 A and the cap  230 B. For an efficient vaporization, an inner surface of the sidewall of the vaporizing chamber  232  may be of a recessed and curved shape, a hemisphere shape, or a semi-elliptic shape.  
         [0048]     One or more heaters (heating unit)  233 H are disposed in at least one of the upper plate  230 A and the cap  230 B. By the heaters  232 H, the upper plate  230 A and the cap  230 B as well as the vaporizing chamber  232  are heated. It is preferable that the heaters  232 H are disposed in the upper plate  230 A and the cap  230 B, respectively. In case of forming PZT, BST or the like on the silicon substrate, the heaters  232 H are controlled such that a temperature of a vaporizing surface  232   a  that will be described later is in a range of 180˜250° C., preferably in a range of 200˜220° C. The gas introduction unit  222  is also heated by the heaters  232 H, so that a temperature of the source gas in the gas introduction unit  222  is maintained at a specified temperature.  
         [0049]     A spraying nozzle  231  is fixed at the center of the cap  230 B. A nozzle port of the spraying nozzle  231  is disposed to face the inside of the vaporizing chamber  232 . To the spraying nozzle  231 , there are connected a liquid source material supply unit LMS of a liquid material mixed with the carrier gas and a carrier gas supply unit CGS. Theses supply units are substantially same as those in  FIG. 10 .  
         [0050]     A narrow passageway  233  is formed between the top surface of the protrusion  232 S of the upper plate  230 A and the inner surface of the cap  230 B. More specifically, both the top surface of the protrusion  232 S and the inner surface of the cap  230 B are coned surfaces which are opposite to each other to have therebetween a fine gap forming the narrow passageway  233 . Therefore, the narrow passageway  233  has an annular shape to surround the vaporizing chamber  232 . As described below, the narrow passageway  233  serves as a path for vaporizing a mist contained in a vaporized gas.  
         [0051]     Further, an annular drain passage  234  is coaxially formed around the narrow passageway  233 . In one portion of the drain passage  234 , there is formed a drain port  234   a  communicating with the reaction chamber  221 A through the gas introduction unit  222 . An opening/closing valve  235  is disposed at the cap  230 B to open or close the drain port  234   a . A valve body  235   a  of the opening/closing valve  235  is placed towards the draining port  234   a.    
         [0052]     Between the drain port  234   a  and the narrow passageway  233 , there is disposed a filter  236  for capturing the mist (solid or liquid phase material in the vaporized gas). More specifically, the filter  236  is placed to surround an outlet  233   a  of the narrow passageway  233 . Further, in another portion of the drain passage  234 , there is disposed a gas exhaust port  234   b  to which an exhaust system (ES) is connected through a gas exhaust path  237   b . An opening/closing valve  237  is disposed at the gas exhaust path  237   b  to exhaust an inside of the drain passage  234 . A valve body  237   a  of the opening/closing valve  237  is disposed to face the gas exhaust port  234   b.    
         [0053]     In the present embodiment, one drain port has been disposed, but two or more drain ports may be disposed in the drain passage  234 . In the same manner, one gas exhaust port has been disposed, but two or more gas exhaust ports may be placed.  
         [0054]     The upper plate  230 A is configured as a lid, which can be opened or closed around a hinge  230 C equipped in an upper edge of the vessel casing  221 . Thus, the upper plate  230 A and the cap  230 B can be rotated as a unit around the hinge  230 C with respect to the vessel casing  221 . In other words, the vaporizer  230  and the gas introduction unit  222  are formed as a part of a lid structure, which can open or close the upper opening of the vessel casing  221 . Therefore, the vaporizer  230  and the gas introduction unit  222  can be opened or closed as a unit for the vessel casing  221 . Moreover, the part forming the vaporizer  230  and the part forming the lid or the gas introduction unit  222  may be configured to be fixed with respect to each other.  
         [0055]      FIG. 2  presents a magnified cross sectional view showing portions from the vaporizing chamber  232  to the draining port  234   a  of the draining passage  234  in the vaporizer  230  of the main body described in  FIG. 1 . As described in  FIG. 2 , mist of a liquid source material is sprayed into the vaporizing chamber  232  from the nozzle port  231   a  of the spraying nozzle  231 . The liquid source material is vaporized instantaneously by colliding with a vaporizing surface  232   a  heated by the heaters  232 H, to thereby become a source gas (reaction gas). The pressure gradient caused by the depressurization in the reaction chamber  221 A makes the source gas flow through the narrow passageway  233  formed around the vaporizing chamber  232  to be introduced into the draining passage  234 .  
         [0056]     As mentioned above, the narrow passageway  233  is opened on the uppermost portion of the vaporizing chamber  232 . Thus, the mist sprayed from the nozzle port  231   a  is hardly injected into the narrow passageway  233  directly. Moreover, fine mist (droplet) that is left without being vaporized when sprayed mist collided with the vaporized surface  232   a  is hard to reach to the filter  236 . For the same reason, the filter  236  is hardly clogged, so that the life span thereof gets prolonged.  
         [0057]     Further, the narrow passageway  233  is configured to be extended slightly tilted downwardly from the opening to the vaporizing chamber  232 . In this way, the mist reached at the opening of the narrow passageway  233  is likely to make a contact with the inner surface of the narrow passageway  233 . Therefore, it is possible to prevent the mist from passing through the narrow passageway  233  to reach the draining passage  234 . Since the inner surfaces (upper and lower surfaces) of the narrow passageway  233  are heated by the heaters  232 H like as the vaporizing surface  232   a , the mist having contacted with the inner surfaces of the narrow passageway  233  is also vaporized therein, to thereby produce the source gas.  
         [0058]     In the present embodiment, the annular narrow passageway  233  is formed as a unit around the vaporizing chamber  232 , but multiple narrow passageways may be annularly (radially) disposed around the vaporizing chamber  232 . Since the narrow passageway  233  is annularly formed around the vaporizing chamber  232 , sufficient flow path cross sectional area can be secured as a whole even though a width of the narrow passageway  233  (a width in the narrowest direction, a vertical width in the drawing) is small.  
         [0059]     It is preferable that the width of the narrow passageway  233  (vertical width) is about, e.g., 0.5˜10.0 mm. Moreover, the width of the passageway (vertical width) may be configured such that the pressure difference between the vaporizing chamber  232  and the reaction chamber connected thereto is about 1.0˜4.5 kPa. If the pressure difference is below the above range, the passageway is likely to be clogged. If the pressure difference is beyond the above range, re-vaporizing capability is drastically lowered. In particular, it is preferable that the width of the passageway (vertical width) is larger (longer distance) than the mean free path (λ) of the mist (e.g., about 10 μm˜100 μm of particle diameter).  
         [0060]     The draining passage  234  is annularly formed along the outer periphery of the vaporizing chamber  232  while having therebetween the narrow passageway  233 . The draining passage  234  is disposed such that the source gas is introduced thereto through the annular narrow passageway  233  and discharged through the draining port  234   a . Thus, it is preferable that the draining passage  234  has a sufficient conductance. In the drawing, the vertical width of the draining passage  234  is substantially equal to that of the vaporizing chamber  232 . The aforementioned valve body  235   a  is disposed above the draining port  234   a  of the draining passage  234  such that it can move vertically. If the valve body  235   a  is lowered to reach the bottom portion of the draining passage  234 , the draining port  234   a  is to be completely shut. On the other hand, if the valve body  235   a  is elevated, conductance of the draining port  234   a  is accordingly increased.  
         [0061]     The filter  236  is of a barrel shape (cylindrical shape in the drawing) as a whole, and installed inside the draining passage  234  to surround the outlet  233   a  of the narrow passageway  233 . More specifically, the filter  236  is disposed in the draining passage  234  to annularly surround the outer side of the narrow passageway  233 . Instead of the filter  236 , a filter  236 ′ (see  FIG. 3 ) that will be discussed later may be employed.  
         [0062]     The filter  236  has a mesh structure formed by a fibrous material of a metal or the like, a nonwoven fabric structure formed by a mass of fibrous material or a porous structure having a plurality of fine holes. More specifically, the filter  236  includes metal supporting frames  236   a  disposed in an upper and a lower portion thereof; and a filter material  236   b  fixed to the supporting frames  236   a . The upper and lower supporting frames  236   a  are fixed to the top surface of the draining passage  234  (e.g., the inner surface of the cap  230 B) and the bottom surface thereof (i.e., the inner surface of the upper plate  230 A), respectively.  
         [0063]     The filter  236  captures the fine mist or the particles contained in the source gas introduced into the draining passage  234 , to prevent the particles from being injected into the reaction chamber  221 . The filter  236  is also heated by the heats from the upper plate  230 A and the cap  230 B. Thus, at least a part of the fine mist captured by the filter  236  is vaporized to become the source gas.  
         [0064]     In the above-described configuration, at the initial stage of the operation of the vaporizer  230 , the draining port  234   a  is closed by the opening/closing valve  235  and the gas exhaust port  234   b  is opened by the opening/closing valve  237 . Then, the liquid source material is sprayed from the spraying nozzle  231 , and the source gas produced in the vaporizing chamber  232  is discharged through the gas exhaust port  234   b  via the narrow passageway  233  and the draining passage  234 . If the vaporizing state of the vaporizer  230  is sufficiently stabilized, the draining port  234   a  is opened by the opening/closing valve  235  while at the same time, the gas exhaust port  234   b  is closed by the opening/closing valve  237 . In this way, the source gas is introduced into the reaction chamber  221 A through the gas introduction unit  222 .  
         [0065]     As for the source gas introduced through the gas introduction unit  222 , there are enumerated, other than an organic metal compound gas such as Pb, Zr, Ti or the like, an organic metal gas for film formation such as Al 2 O 3 , HfO 2 , RuO, ZrO, SBT, BLT, PLZT, STO or the like; a high melting point metal compound gas such as TiCl 4  (tetrachlroride titanium), WF 6  (hexafluoride tungsten), Ta(OC 2 H 5 ) 5  (pentaethoxytantalum) or the like; an organic silicon compound gas such as a pentaethoxysilane or the like. Further, there is introduced into the gas introduction unit  222  a predetermined appropriate additional reaction gas other than the source gas supplied by the vaporizer  230 . As for such an additional reaction gas, there may be enumerated a reducing gas such as H 2 , NH 3 , SiH 4  or SiH 2 Cl 2 ; or an oxidizing gas such as O 2 , O 3 , N 2 O, NO 2 , H 2 O or the like.  
         [0066]     In the present embodiment, the vaporizer  230  is formed as a unit for the reaction chamber  221 A, so that it is unnecessary to prepare a long gas transporting line between the vaporizer  230  and the reaction chamber  221 A. Therefore, there will be a reduced concern that particles are produced during the transportation of the source gas over a long transfer distance. Moreover, it is unnecessary to heat the line for preventing the source gas from being solidified or liquefied in the gas transporting line.  
         [0067]     Further, the vaporizer and the reaction chamber need not be installed individually and connected to each other by the line, so that the entire apparatus can be configured compactly. In particular, the vaporizer  230  is formed as a unit at an outer side of the gas introduction unit  222 , so that the source gas produced in the vaporizer  230  can be directly introduced into the gas introduction unit  222 . Further, the transfer distance of the source gas from the vaporizer  230  to the reaction chamber  221 A can be made short. Thus, production of the particles can be further suppressed, and the supply of the source gas becomes stable. Since the organic metal source gas for use in the film formation of PZT, BST or the like is very expensive, shortening the transfer path of the source gas can prevent waste of the source gas.  
         [0068]     In such a configuration, the vaporizer  230  should be thinner to make the entire apparatus more compact. Therefore, in the present embodiment, the narrow passageway  233  is annularly disposed around the vaporizing chamber  232 , and the draining passage  234  is coaxially disposed around the narrow passageway  233 , as mentioned above. By doing this, it is possible to make the vaporizer  230  very thin while securing sufficient conductances for the vaporizing chamber  232 , the narrow passageway  233  and the draining passage  234 . Moreover, since the outlet  233   a  of the narrow passageway  233  is surrounded by the filter  236 , the filter  236  can be replaced and cleaned by detaching the cap  230 B.  
         [0069]      FIG. 3  presents a magnified cross sectional view showing one portion of a modified exemplary vaporizer  230 ′ described in  FIG. 2 . In the vaporizer  230 ′, a modified cap  230 B′ is prepared; and multiple fine holes  232   c  are formed at an upper portion of the vaporizing chamber  232  (the wall surface where the spraying nozzle  231  is installed). These fine holes  232   c  communicate with an introduction passage  232   d , which communicates with the narrow passageway  233  as formed above.  
         [0070]     In the vaporizer  230 ′, the mist sprayed by the spraying nozzle  231  is vaporized in the vaporizing chamber  232 , and the generated source gas is introduced into the introduction passage  232   d  through the fine holes  232   c . Then, the source gas flows into the narrow passageway  233  through the introduction passage  232   d . After that, the source gas is discharged through the draining port  234   a  via the draining passage  234 , and supplied into the reaction chamber  221 A through the gas introduction unit  222 , same as in the aforementioned embodiment.  
         [0071]     It is preferable that the fine holes  232   c  and the introduction passage  232   d  are annularly configured around the spraying nozzle  231  at the upper portion of the vaporizing chamber  232 . Moreover, the multiple fine holes  232   c  and the introduction passage  232   d  may be annularly (radially) arranged at the upper portion of the vaporizing chamber  232 . In this way, sufficient conductances can be secured in the gas paths towards the narrow passageway  233 .  
         [0072]     In the fine holes  232   c  and the introduction passage  232   d , the fine mist contained in the source gas, which is produced in the vaporizing chamber  232 , is captured to be re-vaporized. Thus, it is possible to reduce the fine mist in the source gas introduced into the narrow passageway  233 , so that vaporization efficiency can be further increased, and at the same time, generation of the particles can be further suppressed. Moreover, in this way, the narrow passageway  233  or the filter  236  disposed in the downstream side can be prevented from being clogged.  
         [0073]     In the present modified example, the filter  236 ′ is of a tube shape (a cylindrical shape in the drawing) as a whole, and installed in the draining passage  234  to surround the valve body  235   a  and the draining port  234   a . More specifically, the filter  236 ′ is disposed inside the draining passage  234  while having its axis aligned vertically and accommodating the draining port  234   a  inside one opening thereof. Another opening periphery of the filter  236 ′ makes a contact with the upper portion of the draining passage  234 . In the barrel shaped filter  236 ′, the valve body  235   a  is accommodated in such a manner that it can move in the vertical direction, i.e., in the axis direction.  
         [0074]     As described above, the filter  236 ′ is disposed in the portion where the valve body  235   a  of the opening/closing valve  235  is accommodated, so that the filter  236 ′ can be installed by using the portion where the valve body  235   a  is accommodated. Thus, it is possible to compactly accommodate the filter  236 ′ without making the draining passage  234  too large. Moreover, the filter  236 ′ can be easily replaced or cleaned by disassembling the opening/closing valve  235 . In case of using a bellows valve, the source gas is adhered to a bellows of the valve body  235   a  to change the bellows, which in turn prevents the generation of the particles. Meanwhile, in the present modified example, the aforementioned filter  236  may be employed instead of the filter  236 ′.  
         [0075]      FIG. 4  is a magnified cross sectional view showing one portion of another modified exemplary vaporizer  230 ″ described in  FIG. 2 . In the vaporizer  230 ″, a modified upper plate  230 A″ and a cap  230 B″ are prepared; and multiple protruded heat transfer units  234   c  are formed at an inner surface of the draining passage  234 ″, i.e., a portion where the filter  236  is installed. These multiple heat transfer units  234   c  make contacts with the surface of a filter material  236   b ; and contact portions thereof are disposed to be substantially uniformly dispersed.  
         [0076]     The heat transfer units  234   c  make thermal contacts with the filter surface of the filter  236 , so that heat transfer is readily conducted from the upper plate  230 A” and the cap  230 B” to the filter  236 , and at the same time, the entire filter surface is more uniformly heated. Thus, accuracy and uniformity of the temperature are improved over the filter surface. Therefore, the mist in the filter  236  is facilitated to be re-vaporized, and the filter is further prevented from being clogged. Meanwhile, in the present modified example, the filter  236 ′ may be used instead of the filter  236 .  
         [0077]      FIGS. 5A and 5B  are of a vertical side view and a vertical front view, respectively, for schematically showing a spraying nozzle that may be used in the vaporizers described in FIGS.  2  to  4 .  FIGS. 5A and 5B  describe cross sectional configurations of vertically cut surfaces normal to each other.  FIGS. 6A  to  6 D offer cross sectional views taken along the lines VIA, VIB, VIC and VID of  FIG. 5A , respectively.  
         [0078]     In this spraying nozzle  231 X, a plurality of different liquid source materials (or gas-liquid mixtures of liquid source material and carrier gas (e.g., Ar, N 2 , H 2  or the like)) are supplied from the lines  107 A,  107 B and  107 C into supply lines  231 A,  231 B and  231 C, respectively, which are disposed individually in the nozzle. Further, the carrier gas introduced from the line  108  is supplied into the supply line  231 D. The supply line  231 D communicates with a plurality of diffusion spaces  231 D 1 ,  232 D 2  and  232 D 3  corresponding to the plurality of liquid source materials. From the respective diffusion spaces, there are extended coaxial paths coaxially formed with the supply lines  231 A,  231 B and  231 C. The liquid source materials supplied by the gas supply lines  231 A,  231 B and  231 C are sprayed to form a mist through the nozzle ports  231   a ,  231   b  and  231   c  by the carrier gas supplied by the coaxial paths.  
         [0079]     Since the plurality of liquid source materials are sprayed through the spraying nozzle  231 X from the respective nozzle ports, it is unnecessary to mix the liquid source materials in a manifold formed at the main line, as described in  FIG. 10 . Further, single-purpose nozzle port for each source is prepared, so that spraying condition (spraying amount of the source material, amount of the carrier gas to be mixed, spraying pressure and the like) can be adjusted.  
         [0080]      FIGS. 7A and 7B  are of a vertical side view and a vertical front view, respectively, for schematically showing additional spraying nozzle that may be used in the vaporizers described in FIGS.  2  to  4 .  FIGS. 7A and 7B  describe cross sectional configurations of vertically cut surfaces normal to each other.  FIGS. 8A  to  8 E present cross sectional views taken along the lines VIIIA, VIIIB, VIIIC, VIIID and VIIIE of  FIG. 5A , respectively.  
         [0081]     In this spraying nozzle  231 Y, a plurality of different liquid source materials (or gas-liquid mixtures of liquid source material and carrier gas) are supplied from the lines  107 A,  107 B and  107 C into the supply lines  231 A,  231 B and  231 C, respectively, which are disposed individually inside the nozzle. Further, the carrier gas introduced from the line  108  is supplied into the supply line  231 D. However, the supply lines  231 A,  231 B and  231 C sequentially join a common supply line at the cross sectional positions described in  FIGS. 8A  to  8 C. Further, the supply line  231 D communicates with the diffusion space  231 D 1  corresponding to the common supply line. From the diffusion space  231 D 1 , there is extended a coaxial path coaxially formed with the common supply line. The liquid source material supplied by the common supply line is sprayed to form a mist through the nozzle port  231   a  by the carrier gas supplied by the coaxial path.  
         [0082]     In the spraying nozzle  231 Y, the plurality of liquid source materials are mixed therein, so that it is unnecessary to mix the liquid source materials in a manifold formed at the main line, as described in  FIG. 10 . Further, multiple kinds of source materials can be uniformly mixed, so that the source mixture is vaporized in the vaporizing space to be supplied into the film forming chamber. In this way, reproducibility of the composition ratio of the film is improved.  
         [0083]      FIG. 9  is a vertical front view for schematically showing still another spraying nozzle that may be used in the vaporizer described in FIGS.  2  to  4 . This spraying nozzle  231 Z is an exemplary nozzle configuration using the liquid source supply system described in  FIG. 10 . Here, as shown in  FIG. 10 , the liquid source material pre-mixed in the main line  107  is supplied into the supply line  231 A in the spraying nozzle  231 Z. The supply line  231 A communicates with a diffusion space  231 A 1 , from which a plurality of supply lines  231 Aa,  231 Ab and  231 A 1   c  are extended.  
         [0084]     Meanwhile, the carrier gas is supplied into the supply line  231 D through the line  108 , and introduced into plural diffusion spaces  231 D 1 ,  231 D 2  and  231 D 3 . From the diffusion spaces  231 D 1 ,  231 D 2  and  231 D 3 , there are extended multiple coaxial paths, which are coaxially formed with the supply lines  231 Aa,  231 Ab and  231 A 1   c.  The liquid source materials supplied by the supply lines  231 Aa,  231 Ab and  231 Ac are sprayed to form a mist by the carrier gas supplied by these coaxial paths through the nozzle ports  231   a ,  231   b  and  231   c , respectively.  
         [0085]     In case when using this spraying nozzle  231 Z, the plurality of liquid source materials are mixed in advance, so that the nozzle can be simply configured. Moreover, since the plural nozzle ports are prepared, the liquid source materials can be efficiently sprayed.  
         [0086]     Further, the gas reaction apparatus and the semiconductor processing apparatus in accordance with the present invention are not limited to the aforementioned examples and modifications may be made without departing from the spirit and scope of the invention. For example, in the above-described embodiments, an example of forming the source gas by mixing the plurality of liquid source materials has been explained. However, the number of liquid source materials in accordance with the present invention is not limited, and only a liquid source may be vaporized in the vaporizer.  
       INDUSTRIAL APPLICABILITY  
       [0087]     In accordance with the gas reaction apparatus and the semiconductor processing apparatus of the present invention, the transfer distance of the reaction gas is short, so that high quality gas reaction can be realized, and at the same time, the apparatus can be simply and compactly formed.