Patent Publication Number: US-2010116210-A1

Title: Gas injector and film deposition apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of Japanese Patent Application No. 2008-288136, filed on Nov. 10, 2008, the contents of which are incorporated herein by reference in their entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a gas injector and a film deposition apparatus. 
     2. Description of the Related Art 
     As a film deposition method in a semiconductor manufacturing process, a process is known in which, after a first reaction gas is made to be adsorbed on a surface of a semiconductor wafer (simply referred to as a wafer, hereinafter) as a substrate or such in a vacuum atmosphere, a gas to be provided is switched to a second reaction gas, one or more layers of atomic layers or molecular layers are formed from reaction of both first and second reaction gases, this cycle is repeated many times, and thus, these layers are laminated to carry out film deposition on the substrate. This process is called ALD (Atomic Layer Deposition) or MLD (Molecular Layer Deposition) (simply referred to as an ALD method, hereinafter). It is possible to control a film thickness with high precision by controlling the number of cycles to repeat the process until in-plane film property uniformity is satisfactory, and thus, the process is effective in achieving a thinner semiconductor device. 
     As an apparatus to carry out such a film deposition method, a method has been studied in which a single-wafer film deposition apparatus provided with a gas shower head at the top center of a vacuum chamber is used, reaction gases are provided from the top to the center of a substrate, and un-reacted reaction gases and reaction by-products are ejected from the bottom of the vacuum chamber. This film deposition method may have a problem such that a long time is required for gas replacement by using a purge gas, the number of repeating cycles is large, for example, hundreds of times of repeating cycles may be required, and thus, a processing time is long. Therefore, an apparatus and a method by which the process can be carried out with a higher throughput is in demand. 
     From the above-mentioned background, Patent Documents 1 through 8 disclose film deposition apparatuses in which plural substrates are disposed in a rotation direction on a turntable in a vacuum chamber, and film deposition is carried out. However, in these film deposition apparatuses, a problem that particles or reaction products adhere to a wafer, a problem that a long purge time is required, a problem that reaction occurs in an unnecessary zone, or such, may be considered. 
     Patent Document 1: U.S. Pat. No. 7,153,542, FIG. 6(a), FIG. 6(b) 
     Patent Document 2: Japanese Laid-Open Patent Application No. 2001-254181, FIG. 1, FIG. 2 
     Patent Document 3: Japanese Patent No. 3144664, FIG. 1, FIG. 2, claim 1 
     Patent Document 4: Japanese Laid-Open Patent Application No. 4-287912 
     Patent Document 5: U.S. Pat. No. 6,634,314 
     Patent Document 6: Japanese Laid-Open Patent Application No. 2007-247066, paragraphs 0023-0025, 0058, FIG. 12 and FIG. 18 
     Patent Document 7: United States Patent Publication No. 2007-218701 
     Patent Document 8: United States Patent Publication No. 2007-218702 
     SUMMARY OF THE INVENTION 
     The present invention has been devised in consideration of the above-mentioned situation, and an aspect of the present invention is to provide a configuration to solve the problems disclosed in the Patent Documents 1-8, and also, to solve a problem which may newly occur in a process of solving the above-mentioned problems. 
     In an aspect of this disclosure, a gas injector has an injector body having a gas inlet and a gas passage; plural gas outflow openings disposed on a wall part of the injector body along a longitudinal direction of the injector body; and a guide member that provides a slit-shaped gas discharge opening extending in the longitudinal direction of the injector body on an outer surface of the injector body, and guides gas flowing from the gas outflow openings to the gas discharge opening. 
     In another aspect of this disclosure, a film deposition apparatus, which forms a thin film of reaction products laminated on a surface of a substrate by repeating a cycle of providing to the surface of the substrate at least two reaction gases in sequence which react to each other in a vacuum chamber, has a turntable in the vacuum chamber; a substrate placing area on the turntable for placing the substrate; a first reaction gas providing part that provides a first reaction gas to a side of the turntable on which the substrate placing area is provided and a second reaction gas providing part that provides a second reaction gas to the side of the turntable, the first and second reaction gas providing parts being apart from one another in a rotation direction of the turntable; a separating zone that separates an atmosphere of a first processing zone for providing the first reaction gas and an atmosphere of a second processing zone for providing the second reaction gas, the separating zone being located between the first processing zone and the second processing zone in the rotation direction of the turntable, the separating zone having a separating gas providing part that provides a separating gas; and an evacuation opening that evacuates the vacuum chamber. At least one of the first and second reaction providing parts is the above-mentioned gas injector, the gas injector extends across the rotation direction of the turntable, and the gas discharge opening of the gas injector faces toward the turntable. 
     Other aspects, features and advantages of this disclosure will be apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a vertical cross-sectional view of a film deposition apparatus in one mode for carrying out the embodiments of the present invention taken along a I-I′ line of  FIG. 3 ; 
         FIG. 2  is a perspective view depicting a general configuration of the inside of the film deposition apparatus; 
         FIG. 3  is a horizontal cross-sectional view of the film deposition apparatus; 
         FIGS. 4A and 4B  are vertical cross-sectional views of the film deposition apparatus depicting processing zones and separating zones; 
         FIG. 5  is a partial vertical cross-sectional view of the film deposition apparatus depicting the separating zone; 
         FIG. 6  depicts a manner of flowing a separating gas or a purge gas; 
         FIG. 7  is a partial perspective view depicting a gas injector provided in the film deposition apparatus; 
         FIG. 8  is a vertical cross-sectional view of the gas injector; 
         FIG. 9  is a perspective view of the gas injector; 
         FIGS. 10A and 10B  are a side view and a bottom view of the gas injector; 
         FIG. 11  illustrates a manner of a first reaction gas and a second reaction gas being separated by the separating gas and ejected; 
         FIG. 12  is a vertical cross-sectional side view of a gas injector in another example; 
         FIG. 13  is a perspective view of the gas injector in the other example; 
         FIGS. 14A and 14B  illustrate an example of a size of projection parts used in the separating zones; 
         FIG. 15  is a horizontal cross-sectional view of a film deposition apparatus in another mode for carrying out the embodiments of the present invention; 
         FIG. 16  is a horizontal cross-sectional view of a film deposition apparatus in further another mode for carrying out the embodiments of the present invention; 
         FIG. 17  is a vertical cross-sectional view of a film deposition apparatus in further another mode for carrying out the embodiments of the present invention; 
         FIG. 18  is a general plan view of one example of a substrate processing system using a film deposition apparatus according to a mode for carrying out the embodiments of the present invention; 
         FIG. 19  is a general plan view of a configuration of a simulation model for film deposition apparatuses in embodiments 1 and 2 and comparison examples 1 and 2; 
         FIGS. 20A ,  20 B,  20 C and  20 D illustrate configurations of reaction gas providing parts in the embodiments 1 and 2 and comparison examples 1 and 2, respectively; and 
         FIG. 21  illustrates simulation results of the embodiments 1 and 2 and comparison examples 1 and 2. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Modes for carrying out the embodiments of the present invention relate to the art of forming a thin film by laminating layers of reaction products as a result of repeating many times a providing cycle that provides in sequence at least two reaction gases that react to each other to a surface of a substrate. 
     Before describing the modes for carrying out the embodiments of the present invention, a film deposition apparatus in a reference example will now be described for the purpose of comparison. The film deposition apparatus in the reference example is a turntable-type film deposition apparatus that may solve the problems disclosed by Patent Documents 1-8. 
     In the film deposition apparatus in the reference example, many gas outflow openings are provided on a bottom surface of a long cylindrical gas nozzle along a longitudinal direction of the gas nozzle that extends along a direction crossing a rotation direction of a turntable. A reaction gas is discharged onto a surface of a wafer placed on a substrate placing area on the turntable that passes under the gas nozzle as the turntable turns. For example, two gas nozzles are used for continuously providing two reaction gases, the turntable turns, and thus, these reaction gases are alternately provided onto the surface of the wafer. Then, for example, a film deposition process experiment was carried out to form a silicon oxide film on the surface of the wafer. As a result, a phenomenon was observed in which a film thickness of the thus-formed film changed to undulate along the longitudinal direction of the gas nozzle. Observing the manner of the change in the film thickness, the change in the film thickness was observed such that, the film was thick at areas passing under the gas outflow openings, and was thin at other areas. That is, it was observed that the gas outflow openings provided on the gas nozzle were reflected as such differences in film thickness of the silicon oxide film on the surface of the wafer. Such a phenomenon will be referred to as “undulation”, hereinafter. 
     Generally speaking, the ALD method is a film deposition method that uses adsorption of reaction gas atoms or molecules onto a surface of a wafer, and thus, it is known that film thickness uniformity is satisfactory. A cause of occurrence of the above-mentioned phenomenon of undulation in the turntable-type film deposition apparatus, although the film deposition method is such that film thickness uniformity is satisfactory, is believed to be as follows. That is, the reaction gas is directly made to blow on the surface of the wafer from the gas outflow openings scattered on the bottom surface of the gas nozzle, and there may be a case where the turntable turns to pass under the gas nozzle at a very high rotational speed such as hundreds of rpm, and so forth. Thereby, before adsorption of the reaction gases reach equilibrium, the wafer moves away from the gas outflow openings, and thus, amounts of the reaction gases adsorbed on the wafer vary between areas immediately below the gas outflow openings and the other areas. 
     In order to avoid the undulation phenomenon, it is necessary to uniformly provide the reaction gas along a longitudinal direction of the nozzle. For this purpose, a slit may be provided that extends along the longitudinal direction of the nozzle, instead of the gas outflow openings. However, the slit may have a large flow rate when the reaction gas passes therethrough, in comparison to the gas outflow openings. Therefore, when the reaction gas is provided to the base end of the gas nozzle, a difference in a discharged gas amount onto the wafer may be large between the base end at which a pressure is high and the extending end at which a pressure is low. As a result, it may be difficult to provide the reaction gas with a uniform concentration. In order to reduce the difference in the discharged gas amount between the base end and the extending end, the gas nozzle having a large pipe diameter may be used. However, in this case, a space required for accommodating the gas nozzle increases accordingly, which may result in an increase in a size of the vacuum chamber and thus, in an increase in a size of the film deposition apparatus. 
     According to modes for carrying out the present invention, by providing a configuration described below, a gas discharged from gas outflow openings provided on a wall part of an injector body included in a gas injector is guided by a guide member, and the gas is provided via a slit-shaped gas discharge opening extending along a longitudinal direction of the injector body. As a result, it is possible to disperse the gas in the direction in which the gas discharge opening extends when the gas is guided by the guide member. Therefore, for example, in a process in which the gas is made to be adsorbed on a surface of a substrate placed on a placing area as a result of the gas being provided onto the substrate by the gas injector, it is possible to provide the gas having a concentration that is uniform in the direction in which the injector body extends. Thereby, in comparison to a case where a gas injector is used in such a way that a gas discharged from gas outflow openings provided on a wall part of an injector body is directly made to blow on a substrate, it is possible to avoid occurrence of such a problem that a gas amount adsorbed on the substrate is different between positions at which the gas outflow openings are provided and the other areas. 
     Therefore, according to modes for carrying out the embodiments of the present invention, it is possible to provide a gas injector that can provide a gas having a concentration that is uniform along a longitudinal direction of an injector body, and to provide a film deposition apparatus provided with the gas injector. 
     A film deposition apparatus according to a mode for carrying out the embodiments of the present invention includes a flat vacuum chamber  1  having an approximately circular plan view shape, and a turntable  2  provided in the vacuum chamber  1 , the turntable  2  having a rotation center at the center of the vacuum chamber  1 , as depicted in  FIG. 1  (cross-sectional view taken along a I-I′ line of  FIG. 3 ). The vacuum chamber  1  is configured such that a top plate  11  can be separated from a chamber body  12 . The top plate  11  is pressed to the side of the chamber body  12  via a sealing member, for example, an O-ring  13 , provided on a top surface of the chamber body  12 , because of a reduced pressure inside, so that airtightness of the vacuum chamber  1  is maintained. In order to separate the top plate  11  from the chamber body  12 , a driving mechanism not depicted is used to lift the top plate  11 . 
     The turntable  2  is fixed to a cylindrical core part  21  at a center part, and the core part  21  is fixed to a top end of a rotation shaft  22  extending vertically. The rotation shaft  22  passes through a bottom part  14  of the vacuum chamber  1 , and a bottom end of the rotation shaft  22  is mounted on a driving part  23  which rotates the rotation shaft  22  around a vertical axis, i.e., clockwise in this example. The rotation shaft  22  and the driving part  23  are held in a tubular case member  20  having an opening at the top. A flange part provided on a top surface of the case member  20  is mounted on a bottom surface of the bottom part  14  of the vacuum chamber  1  in an airtight manner, and airtightness between an inside atmosphere and an outside atmosphere of the case member  20  is maintained. 
     On a surface part of the turntable  2 , as depicted in  FIGS. 2 and 3 , circular recession parts  24  are provided for placing plural, for example, five wafers W which are substrates, along a rotation direction (circumferential direction). It is noted that a wafer W is depicted only in one of the single recession parts  24  in  FIG. 3  for the purpose of convenience for description. However, this example should not be so limited, and it is possible to place five wafers W on the five recession parts  24 , respectively.  FIGS. 4A and 4B  depict exploded views obtained from the turntable  2  being cut concentrically along a circle, and then, being expanded horizontally. Each recession part  24  has a diameter slightly larger than a diameter of the wafer W, for example, by 4 mm. Each recession part  24  has a depth equal to a thickness of the wafer W. Accordingly, when the wafer W is placed in the recession part  24 , a surface of the wafer W is flush with a surface (area other than an area in which the wafer is placed) of the turntable  2 . If a difference between the surface of the wafer W and the surface of the turntable  2  is large, a pressure difference may occur at the step part, and therefore, it is preferable that the surface of the wafer W be flush with the surface of the turntable  2 , from a viewpoint of achieving film thickness in-plane uniformity. To make the surface of the wafer W flush with the surface of the turntable  2  means the wafer W and the surface of the turntable  2  have the same height, or, a difference between the surfaces falls within 5 mm. It is preferable to reduce the difference between the surfaces to zero as much as possible depending on accuracy of finishing or such. On a bottom surface of each recession part  24 , through holes (not depicted) are provided through which, for example, three lifting pins (described later) pass for supporting a rear side of the wafer W and moving the wafer W up and down. 
     The recession parts  24  are provided for the purpose of positioning the wafers W and preventing the wafers W from being removed because of centrifugal force caused by rotation of the turntable  2 . The recession parts  24  are portions corresponding to substrate placing areas. However, the substrate placing area is not limited to such a recession part, and instead, for example, may be plural guide members that guide a circumferential edge of the wafer W provided along a circumferential direction of the wafer W on the surface of the turntable  2 . Alternatively, in a case where a chucking mechanism such as an electrostatic chuck is provided to the side of the turntable  2 , and the wafer W is attracted thereby to the surface of the turntable  2 , an area to which the wafer W is placed as a result of being thus attracted is the substrate placing area. 
     As depicted in  FIGS. 2 and 3 , in the vacuum chamber  1 , a gas injector  31 , a reaction gas nozzle  32  and two separating gas nozzles  41  and  42  extend radially from a center part of the vacuum chamber  1  apart from each other in a circumferential direction of the vacuum chamber  2  (the rotation direction of the turntable  2 ) at positions facing passing areas of the recession parts  24  on the turntable  2 . As a result, the gas injector  31  is disposed to extend in a direction across the rotation direction, i.e., a moving path of the turntable  2 . The gas injector  31 , reaction gas nozzle  32  and the separating gas nozzles  41  and  42  are mounted on, for example, a side circumferential wall of the vacuum chamber  1 , and gas providing ports  31   a ,  32   a ,  41   a  and  42   a , which are base end parts, pass through the side circumferential wall. 
     The gas injector  31 , reaction gas nozzle  32 , and the separating gas nozzles  41  and  42  are, in the example depicted, introduced to the inside of the vacuum chamber  1  from the side circumferential wall of the vacuum chamber  1 . However, instead, they may be introduced from an annular protrusion part  5  described later. In this case, L-shaped conduits are provided that have openings on an outer circumferential surface of the protrusion part  5 ; and on an outer surface of the top plate  11 , the gas injector  31 , reaction nozzle  32  and separating gas nozzles  41  and  42  are connected to the openings on one side of the L-shaped conduits, and the gas providing ports  31   a ,  32   a ,  41   a  and  42   a  are connected to the other openings of the L-shaped conduits outside the vacuum chamber  1 . 
     The gas injector  31  and reaction gas nozzle  32  are connected to a gas providing source of a BTBAS (a bis (tertiary-butylamino) silane (BTBAS) gas (not depicted) that is a first reaction gas, and a gas source of a O 3  (ozone) gas (not depicted) that is a second reaction gas, respectively. Each of the separating gas nozzles  41  and  42  is connected to a gas source (not depicted) of a N 2  gas (nitrogen gas) that is a separating gas. The gas injector  31  and the reaction gas nozzle  32  are also connected to the gas source of the N 2  gas, and provide the N 2  gas as a pressure adjusting gas to processing zones P 1  and P 2 , respectively, when operation of the film deposition apparatus is started. In this example, the gas injector  31 , reaction gas nozzle  32  and separating gas nozzles  41  and  42  are arranged in the stated order clockwise. 
     As depicted in  FIGS. 4A and 4B , gas discharge openings  33  for discharging the O 3  gas are arranged apart from each other in a longitudinal direction on the reaction gas nozzle  32  on a lower side. Further, discharge openings  40  for discharging the separating gas are arranged apart from each other in longitudinal directions on the corresponding separating gas nozzles  41  and  42  on a lower side. A detailed configuration of the gas injector  31  that provides the BTBAS gas will be described later. The gas injector  31  and reaction gas nozzle  32  correspond to a first reaction gas providing part and a second reaction gas providing part, respectively, and respective lower zones are the first processing zone P 1  for causing the BTBAS gas to adsorb on the wafer W, and the second processing zone P 2  for causing the O 3  gas to adsorb on the wafer W. 
     The separating gas nozzles  41  and  42  provide the N 2  gas for the purpose of providing separating zones D that separate respective atmospheres of the first processing zone P 1  and the second processing zone P 2 . On the top plate  11  of the vacuum chamber  1  in the separating zones D, projection parts  4  are provided as depicted in  FIGS. 2-4B . Each of the projection parts  4  has a sectorial plan view shape, projects downward, has the center positioned at the rotation center of the turntable  2 , and divides in a circumferential direction a circle drawn along the vicinity of an inner circumferential wall. The separating gas nozzles  41  and  42  are held in grooves  43  provided to extend in radial directions of the circle at centers in the circumferential direction of the projection parts  4 . That is, distances from central axes of the separating gas nozzle  41  ( 42 ) to both edges (upstream edges and downstream edges in the rotating direction) of the sectors of the projection parts  4  are set to have equal lengths. 
     It is noted that, in the mode for carrying out the embodiments of the present invention, the grooves  43  are provided to divide the projection parts  4  into two equal parts. However, in another mode for carrying out the embodiments of the present invention, the grooves  43  may be provided such that upstream sides of the projection parts  4  from the grooves  43  in the rotation direction of the turntable  2  are wider than downstream sides in the rotation direction, for example. 
     Therefore, on both sides in the circumferential direction of the separating gas nozzles  41  and  43 , flat and low ceiling surfaces  44  (first ceiling surfaces) exist that are bottom surfaces of the projection parts  4 . On both sides of the ceiling surfaces  44  in the circumferential direction, ceiling surfaces  45  (second ceiling surfaces) that are higher than the ceiling surfaces  44  exist. A role of the projection parts  4  is to provide separating spaces that are narrow spaces for the purposed of avoiding infiltration of the first reaction gas and the second reaction gas in between the projection parts  4  and the turntable  2 , and preventing these reaction gases from mixing together. 
     That is, as to the separating gas nozzle  41  for example, the separating gas nozzle  41  avoids infiltration of the O 3  gas from the upstream side in the rotation direction of the turntable  2 , and avoids infiltration of the BTBAS gas from the downstream side in the rotation direction of the turntable  2 . “Avoiding infiltration of the gas” means that the N 2  gas that is the separating gas discharged from the separating gas nozzle  41  diffuses between the first ceiling surface  44  and the top surface of the turntable  2 , and, in this example, blows into a space under the second ceiling surfaces  45  adjacent to the first ceiling surface  44 , whereby infiltration of the gas from the adjacent spaces is avoided. Further, “avoiding infiltration of the gas” not only means completely avoiding infiltration of the gas into the spaces under the projection parts  4  from the adjacent spaces, but also means a case where, although the gas irrupts slightly, it can be ensured that the O 3  gas and the BTBAS gas irrupting from respective sides do not mix together in the spaces under the projection parts  4 . By having such a function, the separating zones D can take the role of separating the atmosphere of the first processing zone P 1  and the atmosphere of the second processing zone P 2 . Accordingly, a degree of narrowness of the narrow spaces is such that a pressure difference between the narrow spaces (the spaces under the projection parts  4 ) and zones adjacent to the spaces (in this example, the spaces under the second ceiling surfaces  45 ) is set to have a magnitude such that the function of “avoiding infiltration of the gas” can be ensured. A specific size of the narrow spaces depends on areas of the projection parts  4  and so forth. It is noted that, needless to say, the gas having been adsorbed on the wafer W can pass the separating zones D, and “avoiding infiltration of the gas” means avoiding infiltration of the gas that is in a gas phase. 
     As depicted in  FIGS. 5 and 6 , the protrusion part  5  is provided to face onto a portion of the turntable  2  that is on the outside of the core part  21 , along an outer circumferential surface of the core part  21 . The protrusion part  5  is provided to continue from portions of the projection parts  4  that are on the side of the rotation center. A bottom surface of the protrusion part  5  has the same height as those of the bottom surfaces (the ceiling surfaces  44 ) of the projection parts  4 .  FIGS. 2 and 3  are views taken from cutting horizontally the top plate  11  at a position higher than the separating gas nozzles  41  and  42  and lower than the above-mentioned ceiling surfaces  45 . It is noted that, the protrusion part  5  and the projection parts  4  should not necessarily be one piece, but may be separate pieces. 
     A specific method for producing a combined structure of the projection part  4  and the separating gas nozzle  41  ( 42 ) is not limited to a method in which the groove  43  is formed at the center of a single sectorial plate for the projection part  4 , and the separating gas nozzle  41  ( 42 ) is placed in the groove  43 . Another method may be applied in which two sectorial plates are used, and are fixed to the bottom surface of the top plate body such as being bolted down or so at both side positions of the separating gas nozzle  41  ( 42 ), for example. 
     In this example, the discharge openings  40  each having a bore diameter of 0.5 mm facing just downward are disposed along the longitudinal direction of the separating gas nozzle  41  ( 42 ), for example, at intervals of 10 mm, on the separating gas nozzle  41  ( 42 ). Also as for the reaction gas nozzle  32 , the discharge openings  33  each having a bore diameter of 0.5 mm facing just downward are disposed along the longitudinal direction of the reaction gas nozzle  32 , for example, at intervals of 10 mm. 
     In this example, the wafer W having a diameter of 300 mm is used as a to-be-processed substrate, and in this case, each projection part  4  has a circumferential length (an arc length of a concentric circle of the turntable  2 ) of 146 mm, for example, at a boundary portion between the projection parts  4  and the protrusion part  5  apart from the rotation center by 140 mm as described later, and has a circumferential length of 502 mm, for example, at the outermost portion of the wafer W placing areas (reception areas  24 ). It is noted that, as depicted in  FIG. 4A , a circumferential length L of the projection part  4  located on both sides from corresponding edges of the separating gas nozzle  41  ( 42 ) at the outermost portion is 246 mm. 
     Further, as depicted in  FIG. 4B , a height h of the bottom surface of the projection part  4 , i.e., the ceiling surface  44  from the surface of the turntable  2  falls, for example, in a range from 0.5 mm through 10 mm, and may preferably be approximately 4 mm. In this case, the rotational speed of the turntable  2  is set to fall, for example, in a range from 1 rpm through 500 rpm. In order to ensure the separating function of the separating zone D, a size of the projection part  4 , and/or the height h between the bottom surface (the first ceiling surface  44 ) of the projection part  4  and the surface of the turntable  2  are set, depending on an operating range of the rotational speed of the turntable  2 , for example, based on an experiment, or such. It is noted that, as the separating gas, not only N 2  gas, but also an inert gas such as Ar gas may be used. Further, not only inert gases, but also hydrogen gas or such may be used. As to a sort of gas, it is not necessary to limit the sort of gas as long as the separating gas does not affect the film deposition process. 
     On the bottom surface of the top plate  11  of the vacuum chamber  1 , i.e., on a ceiling surface of the wafer placing areas (the recession areas  24 ), there are the first ceiling surfaces  44  and the second ceiling surfaces  45  higher than the first ceiling surfaces  44  in the circumferential direction, as mentioned above.  FIG. 1  is a vertical cross-sectional view for a zone in which the high ceiling surfaces  45  are provided.  FIG. 5  is a vertical cross-sectional view for a zone in which the low ceiling surfaces  44  are provided. A peripheral part (a portion on the outer edge side of the vacuum chamber  1 ) of the sectorial projection part  4  is bent to be L-shaped to form a bent part  46  that faces onto the outer end surface of the turntable  2 , as depicted in  FIGS. 2 and 5 . The sectorial projection part  4  is provided in the top plate  11  and the top plate  11  is removable from the chamber body  12 . Therefore, slight spaces exist between the outer end surface of the turntable  2  and an inner circumferential surface of the bent part  46  and between an outer circumferential surface of the bent part  46  and the inner circumferential surface of the chamber body  12 . Therefore, the bent part  46  is provided for the purpose of avoiding infiltration of the reaction gases from both sides to prevent the reaction gases from mixing together, the same as the projection part  4 . Therefore, the space between the inner circumferential surface of the bent part  46  and the outer end surface of the turntable  2  is set to have a size, for example, equal to or similar to the height h of the ceiling surface  44  with respect to the surface of the turntable  2 . That is, in this example, when viewed from a zone on the side of the surface of the turntable  2 , the inner circumferential surface of the bent part  46  is included in an inner circumferential wall of the vacuum chamber  1 . 
     The inner circumferential wall of the chamber body  12  has a vertical surface approaching the outer circumferential surface of the bent part  46  in the separating zone D as depicted in  FIG. 5 . However, in a portion other than the separating zone D, as depicted in  FIG. 1 , the inner circumferential wall of the chamber body  12  is cut out to be concave to the outside to have a rectangular shape in a vertical cross-sectional view, from a portion facing onto the outer end surface of the turntable  2  through a bottom surface part  14 , for example. A space between the circumferential edge of the turntable  2  and the inner circumferential wall of the chamber body  12  in the caved portion communicates with each of the first processing zone P 1  and the second processing zone P 2 , and is used to eject the reaction gases provided to the respective processing zones P 1  and P 2 . The space is referred to as an ejecting zone  6 . On the bottom of the ejecting zone  6 , i.e., on the bottom side of the turntable  2 , as depicted in  FIGS. 1 and 3 , a first evacuation opening  61  and a second evacuation opening  62  are provided. 
     These evacuation openings  61  and  62  are connected to, via corresponding evacuation pipes  63 , a common vacuum pump  64 , for example, that is an evacuation part. It is noted that, a reference numeral  65  denotes a pressure adjustment part that may be provided for each of the evacuation openings  61  and  62 , or may be provided in common for the evacuation openings  61  and  62 . For the purpose of the separating function of the separating zones D functioning positively, the evacuation openings  61  and  62  are provided, in a plan view, on corresponding sides in the rotation direction of the separating zones D, and the evacuation openings  61  and  62  respectively discharge the reaction gases (the BTBAS gas and the O 3  gas) exclusively. In this example, the evacuation opening  61  is provided between the gas injector  31  and the separating zone D adjacent to the gas injector  31  in the downstream side in the rotation direction. The other evacuation opening  62  is provided between the reaction gas nozzle  32  and the separating zone D adjacent to the reaction gas nozzle  32  in the downstream side in the rotation direction. 
     The number of evacuation openings is not limited to two, and, for example, a total of three evacuation openings may be provided such that a further evacuation opening may be provided between the separating zone D including the separating gas nozzle  42  and the second reaction gas nozzle  32  adjacent to this separating zone D in the downstream side in the rotation direction. The number of evacuation openings may be equal to or more than four. In this example, the evacuation openings  61  and  62  are provided at positions lower than the rotation table  2  so that evacuation is carried out from a space between the inner circumferential surface of the vacuum chamber  12  and the circumferential edge of the turntable  2 . However, the positions of the evacuation openings  61  and  62  are not limited to the above-mentioned positions, and the evacuation openings  61  and  62  may be provided in the side wall of the vacuum chamber  1 . When the evacuation openings are provided in the side wall of the vacuum chamber  1 , the evacuation openings may be provided at positions higher than the turntable  2 . Thus providing the evacuation openings  61  and  62 , the gases on the turntable  2  flow to the outside of the turntable  2 , and this configuration is advantageous from a viewpoint such that, in comparison to a case where evacuation is carried out from the top surface that faces onto the turntable  2 , particles can be prevented from being caused to fly up. 
     In a space between the turntable  2  and the bottom surface part  14 , as depicted in  FIGS. 1 and 7 , heater units  7  are provided, that are heating parts and heat the wafers W via the turntable  2  to a temperature determined according to a process recipe. On the downside of the vicinity of the circumferential edge of the turntable  2 , a cover member  71  is provided to surround the entire circumference of each of the heater units  7  for the purpose of dividing an atmosphere in which the heater unit  7  is located and an atmosphere from a space above the turntable  2  through the ejecting zone  6 . A top edge of the cover member  71  is bent outward to have a flange shape, a space between the bent surface and the bottom surface of the turntable  2  is reduced, and thus, infiltration of the gases in the cover member  71  from the outside is avoided. 
     The bottom surface part  14  approaches the vicinity of a center part of the bottom surface of the turntable  2  and the core part  21 , a space therebetween is narrow, further a through hole of the rotation shaft  22  passing through the bottom surface part  14  is such that a space between the rotation shaft  22  and the inner circumferential surface is narrow, and these narrow spaces communicate with the inside of the case member  20 . The case member  20  is provided with a purge gas providing pipe  72  that carries out purge by providing the N 2  gas that is a purge gas to the narrow spaces. Further, to the bottom surface part  14  of the vacuum chamber  1 , purge gas providing pipes  73  are provided at plural portions underneath the heater units  7 , which purge spaces in which the heater units  7  are located. 
     By thus providing the purge gas providing parts  72  and  73 , as depicted in  FIG. 6  that shows a flow of the purge gas, the space from the inside of the case member  20  through the spaces in which the heater units  7  are located is purged by the N 2  gas, and the purge gas is ejected to the evacuation openings  61  and  62  from the space between the turntable  2  and the cover member  71  via the ejecting zone  6 . Thereby, the BTBAS gas and the O 3  gas are prevented from flowing to one to the other of the first processing zone P 1  and the second processing zone P 2  via the downside of the turntable  2 . Thus, the purge gas acts as a separating gas. 
     Further, to the center part of the top plate of the vacuum chamber  1 , a separating gas providing pipe  51  is connected, which provides the N 2  gas that is the separating gas to a space  52  between the top plate  11  and the core part  21 . The separating gas provided to the space  52  is discharged toward the circumferential edge of the turntable  2  along the surface on the side of the wafer placing areas via a narrow space  50  between the protrusion part  5  and the turntable  2 . The space surrounded by the protrusion part  5  is filled with the separating gas, and therefore, the reaction gases (the BTBAS gas and the O 3  gas) are prevented from mixing between the first processing zone P 1  and the second processing zone P 2  via the center part of the turntable  2 . That is, for the purpose of separating the atmospheres of the first processing zone P 1  and the second processing zone  22 , the film deposition apparatus is divided by the rotation center part of the turntable  2  and the vacuum chamber  1  so that a center part zone C is provided in which purging is carried out by using the separating gas and a discharge opening is provided along the rotation direction which discharges the separating gas to the surface of the turntable  2 . This discharge opening corresponds to the narrow space  50  between the protrusion part  5  and the turntable  2 . 
     Further, as depicted in  FIGS. 2 and 3 , in the side wall of the vacuum chamber  1 , a conveyance opening  15  is provided to be used for transferring the wafer W between an external conveyance arm  10  and the turntable  2 , and is opened and closed by means of a gate valve not depicted. Further, a lifting pin and a lifting mechanism (both not depicted) for transferring the wafer W are provided, which lifting pin passes through the recession part  24  as the wafer placing area and lifts the wafer W from the reverse side of the waver W, at a portion under the turntable  2  corresponding to a position for transferring the wafer W, since transfer of the wafer W is carried out from the recession part  24  on the turntable  2  at a position facing the conveyance opening  15  between the recession part  24  and the conveyance arm  10 . 
     In the film deposition apparatus in the mode for carrying out the embodiments of the present invention configured as described above, the reaction gas nozzle  32  that provides the O 3  gas is such that, as mentioned above, the discharge openings  33  are disposed apart from each other provided downward. In contrast thereto, the gas injector  31  that provides the BTBAS gas, for example, has a configuration described below, for the purpose of reducing the above-mentioned undulation of a film. Now, a detailed configuration of the gas injector  31  will be described with reference to  FIGS. 8-10B . 
     As depicted in  FIGS. 8-10B , the gas injector  31  includes an injector body  311 , having a long rectangular tube shape, and is made of, for example, quartz, and a guide member  315  provided to a side surface of the injector body  311 . The inside of the injector body  311  is an empty space, and the empty space acts as a gas passage  312  that is used to flow the BTBAS gas therethrough provided by a gas inlet pipe  317  that is provided to a base end part of the injector body  311 . As depicted in  FIG. 7 , the gas injector body  311  is disposed such that the base end part is directed to the side of the side wall of the chamber body  12 , and the gas inlet pipe  317  is connected to the above-mentioned gas providing port  31   a . A height from the surface of the turntable  2  to a bottom surface of the injector body  311  falls, for example, in a range from 1 mm through 4 mm. The gas inlet pipe  317  has an opening at a connection part of the injector body  311 , and the opening acts as an inlet for introducing the reaction gas into the gas passage  312 . A material of the injector body  311  is not limited to the above-mentioned quartz, and the injector body  311  may be made of ceramic. 
     As depicted in  FIGS. 8 ,  9  and  10 A, plural, for example, 67 gas outflow openings  313  each having a bore diameter of, for example, 0.5 mm, are disposed at intervals of, for example, 5 mm, along a longitudinal direction of the injector body  311 , on a side wall part on one side of the injector body  311 , for example, a side wall on the upstream side in the rotation direction of the turntable  2 . The gas outflow openings  313  provide the BTBAS gas from the gas passage  312  uniformly in a direction in which a gas discharge opening  316  extends. 
     The injector body  311  in the mode for carrying out the embodiments of the present invention has a shape of a rectangular tube as mentioned above. The side wall part having the gas outflow openings  313  is a flat part, and it is preferable that the side wall part be disposed perpendicular to the turntable  2 . The side wall part being thus disposed perpendicular to the turntable  2  means that, it is not necessary to be limited to a case of the side wall part being strictly perpendicular, and includes a case where the side wall part is disposed to have a tilt on the order of ±5° from a plane perpendicular to the turntable  2 . 
     Further, on the side wall part of the injector body  311  on which the gas outflow openings  313  are disposed, the guide member  315  is fixed to face toward the gas outflow openings  313 . The guide member  315  is fixed to the side wall part via a space adjusting member  314 , for example, and thus, the guide member  315  is fixed to the side wall part in such a manner that the guide member  315  and the side wall are in parallel to one another. The guide member  315  is made of, for example, quartz, guides the BTBAS gas discharged from the gas outflow openings  313  to a flowing direction of the BTBAS gas toward the turntable  2 , and also, disperses the flow of the gas so as to avoid a reflection of the gas outflow openings in a film to be formed in a film deposition process. The above-mentioned guide member  315  being in parallel to the side wall part in which the outflow openings  313  are provided is not limited to a case where both members are disposed strictly in parallel to one another, and includes a case where, for example, the guide member  315  is disposed to have a tilt on the order of ±5° from the side wall part. The guide member  315  may also be made of ceramic. 
       FIG. 10A  is a side view of the gas injector  31  where the guide member  315  is removed. The space adjusting member  314  includes, for example, plural sheet members made of quartz and having equal thicknesses, and are disposed at a top side and left and right sides of an area in which the gas outflow openings  313  are disposed so as to surround the area on the side wall part of the injector body  311 . In this example, the thickness of the space adjusting member  314  is, for example, 0.3 mm, and the guide member  315  is fixed to the injector body  311  via the space adjusting member  314 , for example, as being bolted down or so. The space adjusting member  314  may also be made of ceramic. 
     By providing the above-described configuration of the gas injector  31 , the slit-shaped gas discharge opening  316  is provided along one edge of the side wall part that is a flat part, between an outer surface of the side wall part and the guide member  315 , for example, as depicted in  FIG. 10B  that is a bottom plan view, and the gas discharge opening  316  discharges the BTBAS gas discharged from the gas outflow openings  313  to the wafer W. The gas injector  31  is disposed in the vacuum chamber  1  where the gas discharge opening  316  faces toward the turntable  2 . Further, as mentioned above, the thickness of the space adjusting member  314  is 0.3 mm, and a width of the gas discharge opening  316  is also 0.3 mm. 
     Further, in a case where the bolting down is used as mentioned above, the space adjusting member  314  and/or the guide member  315  is detachable from the injector body  311 . Therefore, it is possible to use the space adjusting member  314  having a different thickness to adjust the width of the slit of the gas discharge opening  316 , according to operating conditions such as sorts and/or supply amounts of the reaction gases, the rotational speed of the turntable  2 , and so forth, when the operating conditions are changed, for example. Further, in a case where the guide member  315  is detachable, some of the gas outflow openings  313  may be easily covered by a seal  318  made of a material that is thermally and chemically highly stable, for example, Kapton (registered trademark), and may then be easily removed, as depicted in right side parts of  FIGS. 10A and 10B . Thereby, it is possible to change disposing intervals of the gas outflow openings  313 , make disposing intervals of the gas outflow openings  313  to differ between the base end side and the extending end side of the gas injector  31 , or so, according to a change in the reaction gases, operating conditions, and so forth. 
     Returning to the description of the entire film deposition apparatus, as depicted in  FIGS. 1 and 3 , a control part  100  having a computer is provided to control operation of the entire film deposition apparatus in the film deposition apparatus according to the mode for carrying out the embodiments of the present invention. A computer program for operating the film deposition apparatus is stored in a memory of the control part  100 . In the computer program, a group of steps is incorporated such as to carry out operations of the film deposition apparatus described later. The computer program is installed in the control part  100  from a recording medium such as a hard disk, a compact disc, a magneto-optical disc, a memory card, a flexible disk, or such. 
     Next, operations of the film deposition apparatus in the mode for carrying out the embodiments of the present invention will be described. First, the gate valve not depicted is opened, and the wafer W is transferred to the recession part  24  on the turntable  2  by means of the conveyance arm  10  via the conveyance opening  15  from the outside. The transfer is carried out as a result of, when the recession part  24  stops at a position at which the recession part  24  faces the conveyance opening  15 , the lifting pins not depicted moving upward and downward from the bottom side of the vacuum chamber  1  via the through holes of the bottom surface of the recession part  24 . Then, while the turntable is intermittently rotated, such transfer of the wafers W is carried out, and thus, the wafers W are placed on the five recession parts  24  of the turntable  2 , respectively. Then, the vacuum pump  64  is operated, a pressure adjusting valve of the pressure adjusting part  65  is fully opened, the space, including the respective processing zones P 1  and P 2 , is evacuated to have a previously set pressure, and the wafers W are heated by the heater units  7  while the turntable  2  is rotated clockwise. In more detail, the turntable  2  is previously heated by the heater units  7  to, for example, 300° C., and the wafers W are heated as a result of being placed on the turntable  2 . 
     Parallel to the operation of heating the wafers W, the N 2  gas of an amount equal to those of the reaction gases, separating gas and purge gas that will be provided after a film deposition operation is started, is provided to the vacuum chamber  1 , and a pressure adjustment in the vacuum chamber  1  is carried out. For example, the N 2  gas in respective amounts, such as, 100 sccm from the gas injector  31 , 10,000 sccm from the reaction gas nozzle  32 , 20,000 sccm from each of the separating gas nozzles  41  and  42 , and 5,000 sccm from the separating gas providing pipe  51 , is provided to the vacuum chamber  1 , and opening and closing operations of the pressure adjusting valve is carried out in the pressure adjusting part  65  so that a pressure in each of the processing zones P 1  and P 2  becomes a predetermined pressure set value, for example, 1,067 Pa (8 Torr). It is noted that a predetermined amount of the N 2  gas is provided from each of the purge gas providing parts  72  and  73 . 
     Next, when it is confirmed that a temperature of the wafers W becomes a set temperature by means of a temperature sensor (not depicted), and it is determined that the pressure in each of the first and second processing zones P 1  and P 2  becomes the set pressure, gases to be provided by the gas injector  31  and reaction gas nozzle  32  are switched to the BTBAS gas and the O 3  gas, respectively, and a film deposition operation to the wafers W is started. At this time, it is preferable that the switching of the gases in each of the gas injector  31  and the reaction gas nozzle  32  be carried out slowly, so that the total amount of the gases provided to the vacuum chamber  1  is not changed suddenly. 
     Then, since the wafers W pass through the first and second processing zones P 1  and  22  alternately because of rotation of the turntable  2 , the BTBAS gas is adsorbed on each wafer W, then the O 3  gas is adsorbed on the wafer W, BTBAS molecules are oxidized, one or plural layers of silicon oxide are formed, thus molecular layers of silicon oxide are layered in sequence, and thus, a silicon oxide film with a predetermined thickness is formed. 
     Behavior of the BTBAS gas provided by the gas injector  31  at this time will now be described in detail. The BTBAS gas provided by the gas providing pipe  317  flows in the gas passage  312  from the base end through the extending end of the injector body  311 , and also flows out from the respective gas outflow openings  313  provided in the side wall part of the injector body  311 . At this time, the guide member  315  is provided at a position facing toward the respective gas outflow openings  313 . Therefore, as depicted in  FIG. 8 , for example, the guide member  315  guides the BTBAS gas so that the BTBAS gas discharged from the respective gas outflow openings  313  flows downward, and thus, the BTBAS gas flows toward the gas discharge opening  316 . 
     At this time, since the BTBAS gas discharged from the gas outflow openings  313  hits the guide member  315  and a flowing direction is thus changed, the gas diffuses in left and right directions in which the slit-shaped gas discharge opening  31  extends when the gas hits the guide member  315 , and after that, the gas flows downward, as diagrammatically depicted in  FIG. 9 . Since the gas outflow openings  313  are disposed adjacent to each other in the longitudinal direction of the injector body  311  as descried above, the gas discharged from each of the gas outflow openings  313  flows in such a manner that the gas is mixed together in the longitudinal direction of the gas injector  31  when hitting the guide member  315  and diffusing in the left and right directions. Thus, the gas flows in such a manner that the gas reaches the slit-shaped gas discharge opening  316  while a gas concentration is made uniform in the longitudinal direction of the gas injector  31 , and is provided to the processing zone P 1  as forming a long and narrow strip-shaped flow. 
     Since the BTBAS gas is thus provided to the processing zone P 1  while being mixed in the longitudinal direction of the gas injector  31 , it is possible that the gas can reach the surfaces of the wafers W passing through the processing zone P 1  at a reduced concentration difference in comparison to the above-mentioned case where the nozzle of the reference example is used to provide the gas. As a result, even in a case where the rotational speed of the turntable  2  is high and the wafer W passes through the processing zone P 1  before adsorption of the reaction gas onto the wafer W reaches equilibrium, the BTBAS gas is adsorbed on the surface of the wafer W at a reduced concentration difference between the positions of the gas outflow openings  313  and the positions therebetween, and thus, it is possible to form a film having an undulation that is smaller than that in comparison to the nozzle in the reference example. 
     Further, since the BTBAS gas is provided to the slit-shaped discharge opening  316  via the small gas outflow openings  313  each having a bore diameter of 0.5 mm, for example, the flow rate when the gas flows toward the gas discharge opening  316  from the gas passage  312  in the injector body  311  is small. Therefore, it is possible to avoid occurrence of a phenomenon that occurs in a case where a slit is provided on a bottom side of the gas nozzle in the reference example for the purpose of reducing the above-mentioned phenomenon of undulation as in the reference example, that is, a phenomenon that conduction is large when BTBAS gas flows through the slit, a large concentration difference occurs between the extending end and the base end of the nozzle, and a film thus formed is thick on the base end side and thin on the extending end side on the surface of the wafer W, for example. 
     Next, gas flow in the entirety of the vacuum chamber  1  will be described. The N 2  gas that is the separating gas is provided from the separating gas providing pipe  51  connected to the center part of the top plate  11 , and thereby the N 2  gas is discharged along the surface of the turntable  2  from the center part zone C, i.e., from between the turntable  2  and the center part. In this example, in the inner circumferential wall of the chamber body  12  along the space below the second ceiling surface  45  on which the gas injector  31  and the reaction gas nozzle  32  are disposed, the inner circumferential wall is cut out as mentioned above, thus a wide space is provided, and the evacuation openings  61  and  62  are provided on the bottom of the wide space. Therefore, a pressure in the space under the second ceiling  45  becomes higher than a pressure in each of the narrow spaces under the first ceiling surfaces  44  and the above-mentioned center part zone C.  FIG. 11  diagrammatically depicts a manner of gas flow when the gases are discharged from the respective portions. The O 3  gas is discharged downward from the reaction gas nozzle  32 , hitting the surface of the turntable  2  (both of the surfaces of the wafers W and the surface of the other areas of the turntable  2 ), and flowing toward the upstream side in the rotation direction along the surface flows into the ejecting zone  6  between the circumferential edge of the turntable  2  and the inner circumferential wall of the vacuum chamber  1  with being pressed back by the N 2  gas flowing from the upstream side, and is ejected through the evacuation opening  62 . 
     Further, the O 3  gas discharged downward from the reaction gas nozzle  32 , hitting the surface of the turntable  2  and flowing toward the downstream side in the rotation direction affected by a flow of the N 2  gas discharged from the center part zone C and a suction function of the evacuation opening  62  for being directed to the evacuation opening  62 , but a part thereof goes toward the separating zone D adjacent on the downstream side for flowing to under the sectorial projection part  4 . However, the height and the length in the circumferential direction of the ceiling surface  44  of the projection part  4  are set to be able to avoid infiltration of the gas to under the ceiling surface  44  in process parameters including flow rates of the respective gases. Therefore, also as depicted in  FIG. 4B , the O 3  gas can hardly flow to under the sectorial projection part  4  or, even when a little can flow to under the sectorial projection part  4 , the O 3  gas cannot reach the vicinity of the separating gas nozzle  41 . Then, the O 3  gas is pressed back to the upstream side in the rotation direction, i.e., to the side of the processing zone P 2  by the N 2  gas discharged by the separating gas nozzle  41 , and is ejected through the evacuation opening  62  via the ejecting zone  6  from the space between the circumferential edge of the turntable  2  and the inner circumferential wall of the vacuum chamber  1 , together with the N 2  gas discharged by the center part zone C. 
     The BTBAS gas provided flowing downward from the gas injector  31  and going toward the upstream side and downstream side in the rotation direction along the surface of the turntable  2  cannot at all irrupt to under the sectorial projection parts  4  adjacent on the upstream side and the downstream side in the rotation direction, or, even when it can irrupt there, is then pressed back to the side of the processing zone P 1 , and ejected through the evacuation opening  61  via the ejecting zone  6  from the space between the circumferential edge of the turntable  2  and the inner circumferential wall of the vacuum chamber  1  together with the N 2  gas discharged from the center part zone C. That is, in each separating zone D, although infiltration of the BTBAS gas or the O 3  gas that is the reaction gas flowing in the atmosphere is avoided, gas molecules having been adsorbed on the surfaces of the wafers pass through the separating zones, i.e., under the low ceiling surfaces  44  provided by the sectorial projection parts  4  as they are, and contribute to film deposition. 
     Thus, the BTBAS gas provided by the gas injector  31  is ejected to the evacuation opening  61  as being carried by flow of the N 2  gas flowing around. In this situation, in a case where the BTBAS gas is provided while a flowing direction of the BTBAS gas has a large angle with respect to the turntable  2 , for example, the BTBAS gas is easily caused to fly upward by the N 2  gas flowing around, and may be ejected without reaching the surfaces of the wafers W, which may thus result in degradation in a film deposition rate. 
     In this point, the gas injector  31  in the mode for carrying out the embodiments of the present invention is configured such that, the side wall part of the injector body  311  in which the outflow openings are provided is disposed as being perpendicular to the turntable  2 , and further, the guide member  315  is disposed parallel to the side wall part. Therefore, the strip-shaped flow of the BTBAS gas provided to the processing zone P 1  via the discharge opening  316  provided therebetween is perpendicular to the turntable  2 . As a result, a distance from the gas discharge opening  316  of the gas injector  31  to the turntable  2  becomes the shortest, and also, an inertial force applied to the BTBAS gas exiting the opening is such that force in a perpendicular direction toward the turntable  2  is the maximum. Accordingly, in comparison to a case where the gas is provided in a direction inclined with respect to the turntable  2 , the BTBAS gas is provided to the processing zone P 1  so that the BTBAS gas is not easily caused to fly upward by the surrounding flow of the N 2  gas. 
     Returning to the description of gas flow in the entirety of the vacuum chamber  1 , when the BTBAS gas in the first processing zone P 1  (the O 3  gas in the second processing zone P 2 ) irrupts into the center part zone C, the infiltration is avoided by the separating gas, or, even when the gas irrupts, the gas is pressed back, since the separating gas is discharged toward the periphery of the turntable from the center part zone C as depicted in  FIGS. 6 and 11 . Therefore, the BTBAS gas (O 3  gas) is prevented from irrupting into the second processing zone P 2  (first processing zone P 1 ) through the center part zone C. 
     Then, in the separating zone D, the peripheral part of the sectorial projection part  4  is bent downward, the space between the bent part  46  and the outer end surface of the turntable  2  becomes narrow as mentioned above, and thus, passage of the gas is substantially avoided. Therefore, the BTBAS gas in the first processing zone P 1  (the O 3  gas in the second processing zone P 2 ) is also prevented from flowing into the second processing zone P 2  (first processing zone P 1 ) via the outside of the turntable  2 . Accordingly, the two separating zones D completely separate the atmosphere in the first processing zone P 1  and the atmosphere in the second processing zone P 2 , and the BTBAS gas is ejected to the evacuation opening  61  and the O 3  gas is ejected to the evacuation opening  62 . As a result, both the reaction gases, in this example, the BTBAS gas and the O 3  gas, do not mix together on the wafers W even in the atmosphere. It is noted that, in this example, since the N 2  gas is used to purge the space below the turntable  2 , it is not possible at all that the gas flowing into the ejecting zone  6  passes through under the turntable  2  and thus, for example, it is not possible that the BTBAS gas flows into the zone in which the O 3  gas is provided. When the film deposition operation is thus finished, each wafer W is conveyed out in an operation by means of the conveyance arm  10  reverse to the operation of conveying the wafer W in. 
     Processing parameters in one example will now be described. The rotational speed of the turntable  2  falls within a range from 1 rpm through 500 rpm, for example, in a case where a wafer W having a diameter of 300 mm is the to-be-processed substrate. In this case, a process pressure is, for example, 1,067 Pa (8 Torr); a heating temperature of the wafer W is, for example, 350° C.; flow rates of the BTBAS gas and the O 3  gas are, for example, 100 sccm and 10,000 sccm, respectively; and a flow rate of the N 2  gas from the separating gas nozzles  41  and  42  is, for example, 20,000 sccm. A flow rate of the N 2  gas from the separating gas providing pipe  51  at the center part of the vacuum chamber  1  is, for example, 5,000 sccm. Further, the number of cycles of providing the reaction gases to a single wafer W, i.e., the number of times of the wafer W passing through each of the processing zones P 1  and P 2  depends on a target film thickness, is large, for example, 6,000 times. 
     Advantages of the above-described mode for carrying out the embodiments of the present invention are as follows: the BTBAS gas discharged from the plural gas outflow openings  313  provided in the side wall part of the injector body  311  included in the gas injector  31  is guided by the guide member  315 , and is provided via the slit-shaped gas discharge opening  316  extending along the longitudinal direction of the injector body  311 . Therefore, when the reaction gas is guided by the guide member  315 , the reaction gas can be diffused in the directions in which the slit extends. As a result, in the film deposition apparatus in the mode for carrying out the embodiments of the present invention in which the reaction gas from the gas injector  31  is provided to the wafers W placed on the placing areas of the turntable  2  and the reaction gas is adsorbed on the surfaces of the wafers W, it is possible to provide the gas having a uniform concentration in the direction in which the injector body  311  extends. Thereby, in comparison to a case where the gas discharged from gas outflow openings provided in a wall of an injector body is directly made to blow is used, such a problematic situation that gas amounts adsorbed on the substrate are different between a zone for which the gas outflow opening is provided and the other zones can be avoided, and thus, it is possible to form a uniform film. 
     Further, when the BTBAS gas is made to hit the guide member  315  and thus is guided, the gas is flowed out via the gas outflow openings  313  that are disposed in the direction in which the injector body extends. The gas outflow openings  313  have small flow rates in comparison to, for example, a slit or such. Therefore, it is possible to avoid a problematic situation where, for example, a concentration difference occurs between the base end of the gas injector  31  close to the gas source of the BTBAS gas and the extending end far away from the gas source, and a thickness of a formed film becomes thick on the base end side on the surface of the wafer W and thin on the extending end side along the direction in which the gas injector  31  extends. 
     Further, the gas injector  31  is disposed in such a manner that the side wall part of the injector body  311  is disposed perpendicular to the turntable  2 , and also, the guide member  315  is disposed parallel to the side wall part. Thereby, the BTBAS gas is provided in such a manner that a flow direction of the BTBAS gas is perpendicular to the turntable  2 . As a result, in comparison to a case where the gas is provided in an inclined direction with respect to the turntable  2 , it is possible to provide the BTBAS gas to the processing zone  21  so that the BTBAS gas is not easily caused to fly upward by a surrounding flow of the N 2  gas, and it is possible to efficiently adsorb the BTBAS gas on the surfaces of the wafers W. 
     Further, in the gas injector  31  according to the mode for carrying out the embodiments of the present invention, the guide member  315  and the space adjusting member  314  may be detachable from the injector body  311 . Therefore, it is possible to change disposing intervals of the gas outflow openings  313  by, for example, sticking seals  318  over some of the gas outflow openings  313 ; it is possible to change a width of the slit of the gas discharge opening  316  by changing a thickness of the space adjusting member  314 ; or so, after removing the guide member  315 , and thus, it is possible to easily modify the gas injector  31 , and it is possible to improve flexibility in BTBAS gas providing conditions. 
     Further, in the film deposition apparatus in the mode for carrying out the embodiments of the present invention, the plural wafers W are disposed in the rotation direction of the turntable  2 , the turntable  2  is rotated, the first processing zone P 1  and the second processing zone P 2  are alternately passed through thereby, and thus, so-called ALD (or MLD) is carried out. Thereby, in comparison to the above-mentioned case where the single-wafer film deposition apparatus is used, a time for purging the reaction gases becomes unnecessary, and thus, it is possible to carry out film deposition with high throughput. 
     Next, a gas injector  31   a  according to another mode for carrying out the embodiments of the present invention will now be described. A film deposition apparatus applying the gas injector  31   a  according to this other mode for carrying out the embodiments of the present invention is the same as that described above with reference to  FIGS. 1-7 , and duplicate descriptions therefor will be omitted. Further, for components having the same function as those of the gas injector  31  described above with reference to  FIGS. 8-10B , the same reference numerals are given. 
     The gas injector  31   a  in the other mode for carrying out the embodiments of the present invention is different from the gas injector  31  in the above-mentioned mode for carrying out the embodiments of the present invention in which the rectangular tube injector body  311  and the flat guide member  315  are provided, in that, as depicted in  FIGS. 12 and 13 , an injector body  311  is configured as a cylindrical member, and the guide member  315  is configured as a member having a circular-arc section. 
     In this example, on a side wall surface of the cylindrical injector body  311  made of quartz, for example, plural, for example, 34 gas outflow openings  313  having a diameter of 0.5 mm, for example, are disposed along a longitudinal direction of the injector body  311  at intervals of 10 mm for example. Further, the guide member  315  is configured such that, for example, one side extending along a longitudinal direction of a member having a circular-arc longitudinal section obtained from a cylinder having a diameter larger than that of the injector body  311  being cut out in a radial direction is fixed to an outer surface of the injector body  311  by means of welding, for example. In other words, a section of the guide member  315  is a circular arc extending along with the outer surface of the injector body  311 . 
     A slit-shaped gas discharge opening  316  for discharging the BTBAS gas is provided between an outer surface side wall part which is a wall part of the injector body  311  in which the gas outflow openings  313  are provided, and the guide member  315 . As depicted in  FIG. 13 , the BTBAS gas discharged from the gas outflow openings  313  flows while hitting the guide member  315  and spreading to left and right sides, is mixed in the longitudinal direction of the gas injector  31   a , and is provided to the processing zone P 1 . As a result, also in the gas injector  31   a  in the other mode for carrying out the embodiments of the present invention, it is possible to provide the BTBAS gas to the processing zone P 1  with a reduced concentration difference, and it is possible to form a film with reduced undulation in comparison to the nozzle in the reference example. 
     Further, also in this example, the gas injector  31   a  provides the BTBAS gas from the gas passage  312  via the gas outflow openings  313  having small flow rates. Therefore, in comparison to a case where a slit having a large flow rate is provided in a bottom surface of a gas nozzle as in the reference example for the purpose of reducing the undulation phenomenon, for example, a concentration difference between the base end and the extending end of the gas injector  31   a  is small and it is possible to form a film having a uniform thickness between the base end side and the extending end side on a surface of a wafer W. 
     In the gas injector  31   a  in the other mode for carrying out the embodiments of the present invention, a width of the slit-shaped gas discharge opening  316  viewed from the bottom is, for example, 2 mm, as depicted in  FIG. 12 . It is possible to adjust this opening width by changing an angle at which the guide member  315  is fixed to the injector body  311 , and by changing a difference in a diameter between the injector body  311  and the guide member  315 . As depicted in  FIG. 12 , the BTBAS gas is provided to the processing zone P 1  with an oblique inclination from a direction in which the gas discharge opening  316  is opened. Therefore, a distance from the gas discharge opening  316  to the turntable  2  is long, and further, an inertia force in a lateral direction is applied to a flow of the BTBAS gas. Therefore, in comparison to the gas injector  31  described above with reference to  FIG. 9  and so forth, the BTBAS gas may be easily caused to fly upward by the surrounding N 2  gas. In this point, the gas injector  31  has higher efficiency when providing the BTBAS gas to the wafers W. Further, the above-mentioned gas injector  31  in which the opening width of the opening part is adjusted by using the space adjusting member  314  is advantageous such that adjustment of the opening width is easy. 
     The gas injectors  31  and  31   a  according to the above-mentioned modes for carrying out the embodiments of the present invention are applied as the first reaction gas providing part that provides the BTBAS gas as a reaction gas. However, a gas applicable to the gas injectors  31  and  31   a  is not limited to the BTBAS gas. For example, the gas injectors  31  and  31   a  may be applied as the second reaction gas providing part, and may provide the O 3  gas that is the second reaction gas. 
     Further, in the above-mentioned respective modes for carrying out the embodiments of the present invention, the gas discharge opening  316  is disposed in the upstream side in the rotation direction of the turntable  2  as an example depicted in  FIGS. 4A and 4B , for example. However, the position of disposing the gas discharge opening  316  is not limited to that described above for the above-mentioned modes for carrying out the embodiments of the present invention. For example, the gas injector  31  may be configured such that the side wall part in which the gas outflow openings  313  are disposed, the space adjusting member  314  and the guide member  315  are disposed in bilateral symmetry to the example depicted in  FIG. 8 , and the gas injector  31  may be disposed on the downstream side in the rotation direction of the turntable  2 . 
     The reaction gases that may be used in the film deposition apparatus according to the above-mentioned modes for carrying out the embodiments of the present invention are, in addition to the above-mentioned examples, dichlorosilane (DCS), hexachlorodisilane (HCD), Trimethyl Aluminum (TMA), tetrakis-ethyl-methyl-amino-zirconium (TEMAZr), tris(dimethyl amino) silane (3DMAS), tetrakis-ethyl-methyl-amino-hafnium (TEMHf), bis(tetra methyl heptandionate) strontium (Sr(THD) 2 ), (methyl-pentadionate)(bis-tetra-methyl-heptandionate) titanium (Ti(MPD)(THD)), monoamino-silane, or the like. 
     The first ceiling surface  44  that provides the narrow space in the position of the separating gas nozzle  41  ( 42 ) may preferably have a width dimension L of 50 mm or more along the rotation direction of the turntable  2  at a portion at which the center WO of the wafer W passes, in a case where, for example, the wafer W of 300 mm diameter is used as a to-be-processed substrate, as the separating gas providing nozzle  41  is typically depicted in  FIGS. 14A and 14B . In order to effectively avoid infiltration of the reaction gas to the space (narrow space) below the projection part  4  from both sides of the projection part  4 , in a case where the above-mentioned width dimension L is short, it is necessary to reduce a distance between the first ceiling surface  44  and the turntable  2  accordingly. Further, when the distance between the first ceiling surface  44  and the turntable  2  is set to be a certain dimension, the speed of the turntable  2  becomes higher as a position becomes farther away from the rotation center, the width dimension L required for obtaining the reaction gas infiltration avoiding function becomes larger as the position is farther away from the rotation center of the turntable  2 . In consideration of this viewpoint, when the above-mentioned width dimension L is smaller than 50 mm at the portion at which the center WO of the wafer W passes through, it is necessary to considerably reduce the distance between the circuit ceiling surface  44  and the turntable  2 . Therefore, in order to avoid collision between the turntable  2  or the wafer W and the ceiling surface  44  while the turntable  2  is rotated, it is necessary to take measures to reduce the deflection of the turntable  2  as much as possible. Further, the higher the rotational speed of the turntable  2  becomes, the more easily the reaction gas irrupts into the space under the projection part  4  from the upstream side of the projection part  4 . Therefore, when the width dimension L is smaller than 50 mm, the rotational speed of the turntable  2  should be reduced, which is not advantageous from a throughput viewpoint. Therefore, it is preferable that the width dimension L be equal to or more than 50 mm. However, when the width dimension L is less than 50 mm, the advantageous effect of the modes for carrying out the embodiments of the present invention can still be obtained. That is, it is preferable that the width dimension L fall within a range from 1/10 through 1/1 of the diameter of the wafer W, and it is more preferable that the width dimension L be equal to or more than approximately ⅙ of the diameter of the wafer W. It is noted that, in  FIG. 14A , for the purpose of convenience in illustration, the recession parts  24  are omitted. 
     Another example of respective layouts of the processing zones P 1  and P 2  and the separating zones D than those of the above-mentioned mode for carrying out the embodiments of the present invention will now be described.  FIG. 15  depicts an example in which the reaction gas nozzle  32  providing the O 3  gas is located on the upstream side in the rotation direction of the turntable  2  with respect to the conveyance opening  15 , and, also in the layouts, the same advantages can be obtained. 
     Further, the gas injectors  31  and  31   a  ( FIG. 16  depicts only the gas injector  31 ) according to the modes for carrying out the embodiment of the present invention may be applied to a film deposition apparatus configured as mentioned below. That is, although it is necessary to provide the low ceiling surface (first ceiling surface)  44  for providing the narrow spaces on both sides of the separating gas nozzle  41  ( 42 ), further, similar low ceiling surfaces may be provided also on both sides of the gas injector  31  or  31   a  (the reaction gas nozzle  32 ) as depicted in  FIG. 16 , and these ceiling surfaces may be made continuous. In other words, the projection part  4  may be provided throughout the entire area facing toward the turntable  2 , except portions for the separating gas nozzles  41  and  42 , the gas injector  31  or  31   a  and the reaction gas nozzle  32 . In this configuration, from another viewpoint, the first ceiling surfaces  44  on both sides of the separating gas nozzle  41  ( 42 ) extend through the gas injector  31  or  31   a  and the reaction gas nozzle  32 . In this case, the separating gas diffuses to both sides of the separating gas nozzle  41  ( 42 ), the reaction gas diffuses to both sides of the gas injector  31  or  31   a  (the reaction gas nozzle  32 ), and both gases merge under the projection part  4  (narrow space). However, these gases are ejected via the evacuation openings  61  ( 62 ) located between the gas injector  31  or  31   a  (reaction gas nozzle  32 ) and the separating gas nozzle  42  ( 41 ). 
     In the above-mentioned modes for carrying out the embodiments of the present invention, the rotation shaft  22  of the turntable  2  is located at the center part of the vacuum chamber  1 , and the separating gas is used to purge the space between the center part of the turntable  2  and the top surface part of the vacuum chamber  1 . However, a film deposition apparatus to which the gas injectors  31  and  31   a  are applicable may be configured as depicted in  FIG. 17  for example. In the film deposition apparatus depicted in  FIG. 17 , a bottom surface part  14  in a center zone of the vacuum chamber  1  projects downward to provide a holding space  80  for a driving part. Further, a recession part  80   a  is provided on a top surface of the center zone of the vacuum chamber  1 , a support  81  is inserted between the bottom of the holding space  80  and the top surface of the recession part  80   a  at the center part of the vacuum chamber  1 , and the BTBAS gas from the gas injector  31  and the O 3  gas from the reaction gas nozzle  32  are prevented from mixing together via the center part of the vacuum chamber  1 . 
     A mechanism for rotating a turntable  2  is such that a rotation sleeve  82  is provided to surround the support  81 , and the ring-shaped turntable  2  is provided along the rotation sleeve  82 . Then, a driving gear  84  is provided which is driven by a motor  83  in the holding space  80 , and the rotation sleeve  82  is rotated by the driving gear  84  via a gear part  85  provided on the lower, outer circumference of the rotation sleeve  82 . Reference numerals  86 ,  87  and  88  denote bearing parts. A purge gas providing pipe  74  is connected to the bottom of the holding space  80 , and a purge gas pipe  75  for providing a purge gas to a space between a side surface of the recession part  80   a  and a top end part of the rotation sleeve  82  is connected to a top part of the vacuum chamber  1 . In  FIG. 17 , left and right openings that provide a purge gas to the space between the side surface of the recession part  80   a  and the top end part of the rotation sleeve  82  are depicted. However, it is preferable to design the number of opening parts (purge gas providing openings) to be provided for the purpose of preventing the BTBAS gas and the O 3  gas from mixing together via a zone in proximity to the rotation sleeve  82 . 
     In the mode for carrying out the embodiments of the present invention depicted in  FIG. 17 , when viewed from the side of the turntable  2 , the space between the side surface of the recession part  80   a  and the top end part of the rotation sleeve  82  acts as the separating gas discharge opening, and the center part zone located at the center part of the vacuum chamber  1  is provided by the separating gas providing opening, the rotation sleeve  82  and the support  81 . 
       FIG. 18  depicts a substrate processing apparatus using the film deposition apparatus described above. In  FIG. 18 , reference numeral  101  denotes a sealed conveyance container called hoop that holds 25 wafers W, for example; reference numeral  102  denotes an atmospheric conveyance chamber in which a conveyance arm  103  is disposed; reference numerals  104  and  105  denote load lock chambers (spare vacuum chamber) in which the atmosphere can be switched between an atmospheric atmosphere and a vacuum atmosphere; reference numeral  106  denotes a vacuum conveyance chamber in which there are two conveyance arms  107 ; reference numerals  108  and  109  denote the film deposition apparatuses according to the modes for carrying out the embodiments of the present invention. The conveyance container  101  is conveyed from the outside to a conveyance in/out port provided with a placing table not depicted, is then connected to the atmospheric conveyance chamber  102 . After that a lid of the conveyance container  101  is opened by an opening/closing mechanism not depicted, and the conveyance arm  103  takes out a wafer W from the inside of the conveyance container  101 . Next, the wafer W is conveyed into the load lock chamber  104  ( 105 ), the atmosphere in the load lock chamber is switched into a vacuum atmosphere, after that the wafer W is taken out by the conveyance arm  107 , and is conveyed into the film deposition apparatus  108  or  109 ; and then, the above-mentioned film deposition process is carried out on the wafer W in the film deposition apparatus  108  or  109 . By providing plural, for example, two film deposition apparatuses according to the mode for carrying out the embodiments of the present invention, for example, each processing five wafers W, for example, it is possible to carry out ALD (MLD) with high throughput. 
     EMBODIMENT 
     Simulation 
     A turntable-type film deposition model was produced, reaction gas providing parts having various shapes were applied, and concentration distributions of provided gases were confirmed. As depicted in  FIG. 19 , the film deposition model was configured such that, for example, the first processing zone P 1  depicted in  FIG. 3  was included, and the turntable  2 , the first reaction gas providing part and the first evacuation opening  61  were disposed in the sectorial space surrounded by the two projection parts  4 . The first reaction gas providing part was disposed at the center in the circumferential direction of the sectorial space depicted in  FIG. 19 , and the evacuation opening  61  was disposed, with respect to the first reaction gas providing part, to the downstream side in the rotation direction of the turntable  2 , at the periphery of and below the turntable  2 . A size of a model space such as an inter-circumferential length L 1 , an outer circumferential length L 2 , and a radial length R of the sectorial space, a height of the ceiling surface  45  (second ceiling surface) not depicted in  FIG. 19  from the top surface of the turntable  2 , and so forth, was the same as that of the actual film deposition apparatus. Further, an amount of providing the BTBAS gas from each reaction gas providing part, amounts of the N 2  gas provided to the sectorial space from the upstream and downstream sides, the rotational speed of the turntable  2 , a process pressure in the space and so forth were set in the parameter ranges mentioned above as the examples of the processing parameters. 
     A. Simulation Conditions 
     Embodiment 1 
     As the first reaction gas providing part, a gas injector  31  the same as that according to the mode for carrying out the embodiments of the present invention depicted in  FIGS. 8-10B  was provided, and a concentration distribution of the BTBAS gas just under the gas injector  31  was simulated.  FIG. 20A  diagrammatically depicts a vertical-section side view of the gas injector  31  used in the simulation. Design conditions of the gas injector  31  were as follows: 
     Diameter of gas outflow opening  313 : 0.5 mm 
     Interval between centers of gas outflow openings  313 : 5.0 mm 
     Disposed number of gas outflow openings  313 : 67 
     Width of slit of gas discharge opening  316 : 0.3 mm 
     Height H 1  from top surface (surface of wafer W) of turntable  2  through gas discharge opening  316 : 4 mm 
     Embodiment 2 
     As the first reaction gas providing part, a gas injector  31   a  the same as that according to the other mode for carrying out the embodiments of the present invention depicted in  FIGS. 12-13  was provided, and a concentration distribution of the BTBAS gas just under the gas injector  31   a  was simulated.  FIG. 20B  diagrammatically depicts a vertical-section side view of the gas injector  31   a  used in the simulation. Design conditions of the gas injector  31   a  were as follows: 
     Diameter of gas outflow opening  313 : 0.5 mm 
     Interval between centers of gas outflow openings  313 : 10 mm 
     Disposed number of gas outflow openings  313 : 32 
     Width of slit of gas discharge opening  316  viewed from bottom: 2.0 mm 
     Height H 1  from top surface (surface of wafer W) of turntable  2  through gas discharge opening  316 : 4 mm 
     Comparison Example 1 
     As the first reaction gas providing part, a reaction gas nozzle  91  depicted in  FIG. 20C  in the reference example was provided, and a concentration distribution of the BTBAS gas just under the reaction gas nozzle  91  was simulated. The reaction gas nozzle  91  was configured to be approximately the same as the reaction gas nozzle  32  described above with reference to  FIGS. 2 and 3  for providing the O 3  gas, had a configuration such that gas outflow openings  93  were disposed along a longitudinal direction at intervals on a bottom surface of the cylindrical reaction gas nozzle  91 . Design conditions of the reaction gas nozzle  91  were as follows: 
     Diameter of gas outflow opening  93 : 0.5 mm 
     Interval between centers of gas outflow openings  93 : 10 mm 
     Disposed number of gas outflow openings  93 : 32 
     Height H 1  from top surface (surface of wafer W) of turntable  2  through gas outflow openings  93 : 4 mm 
     Comparison Example 2 
     As the first reaction gas providing part, a reaction gas nozzle  92  depicted in  FIG. 20D  in the reference example was provided, and a concentration distribution of the BTBAS gas just under the reaction gas nozzle  92  was simulated. The reaction gas nozzle  92  in (comparison example 2) was different from the above-mentioned reaction gas nozzle  91  in (comparison example 1) in that the reaction gas nozzle  91  was rotated 90° counterclockwise viewed from the base end side, and thus, the gas outflow openings  93  faced onto the upstream side in the rotation direction of the turntable  2  as depicted in  FIG. 20D . Design conditions of the reaction gas nozzle  92  were as follows: 
     Diameter of gas outflow opening  93 : 0.5 mm 
     Interval between centers of gas outflow openings  93 : 10 mm 
     Disposed number of gas outflow openings  93 : 32 
     Height H 1  from top surface (surface of wafer W) of turntable  2  through centers of gas outflow openings  93 : 4 mm 
     B. Simulation Result 
       FIG. 21  depicts concentration distributions of the BTBAS gas in the respective embodiments and comparison examples. An abscissa axis of  FIG. 21  depicts a distance [mm] from the center side of the turntable  2  in such a manner that a position of the wafer W of a diameter 300 mm passing below the above-mentioned reaction gas providing part (gas injector  31  or  31   a , or the reaction gas nozzle  91  or  92 ) corresponding to the innermost end on the center side of the turntable  2  is indicated as 0 mm and a position corresponding to the outermost end on the periphery side of the turntable  2  is indicated as 300 mm. Further, an ordinate axis of  FIG. 21  denotes a concentration [%] of the reaction gas (BTBAS) on the top surface of the turntable  2  just under each reaction gas providing part (gas injector  31  or  31   a , or the reaction gas nozzle  91  or  92 ), i.e., on the surface of the wafer W. In  FIG. 21 , a result of (Embodiment 1) is indicated by a bold solid line, a result of (Embodiment 2) is indicated by a thin solid line, a result of (Comparison Example 1) is indicated by a broken line and a result of (Comparison Example 2) is indicated by a dashed line. 
     According to the result of (Embodiment 1) indicated by the bold solid line, such a large undulation phenomenon appearing in (Comparison Example 1) described below did not appear in the reaction gas concentration distribution provided to the surface of the wafer W. However, in the simulation result of (Embodiment 1), the reaction gas concentration provided to the surface of the wafer W gently decreased from the center side through the periphery side of the turntable  2 , and results in an ever-decreasing trend line in  FIG. 21 . This is considered to be because, since the turntable  2  is rotated as a simulation condition, a moving distance per unit time of the turntable  2  is long on the periphery side of the quickly rotating turntable  2 . As a result, the reaction gas is transported far during a short time, and the gas concentration is low. In contrast thereto, on the center side on the quick rotating turntable  2 , a distance for which the reaction gas is transported is short in comparison to the periphery side, and the gas concentration is high. 
     Further, since, as depicted in  FIG. 19 , the first evacuation opening  61  is disposed at the outer circumferential position on the downside of the turntable  2 , an influence of a force of ejecting the gas provided by the gas injector  31  being strong on the periphery side of the turntable  2  near to the evacuation opening  61 , and the force of ejecting the gas being weak on the center side of the turntable  2  far from the evacuation opening  61  is also considered. Such a concentration distribution can be adjusted such that the concentration distribution becomes uniform between the center side and the periphery side of the turntable  2  as a result of, as depicted in  FIGS. 10A and 10B , some of the gas outflow openings  313  being sealed by means of the seal  318  or such so that the intervals of disposing the gas outflow openings  313  are increased at an area at which the reaction gas concentration is high, or so. The phenomenon that the concentration distribution of the reaction gas provided to the surface of the wafer W is in an ever-decreasing manner in  FIG. 21  is also observed in (Embodiment 2), (Comparison Example 1) and (Comparison Example 2). A cause thereof is considered the same as that described above for (Embodiment 1). 
     Further, according to the simulation result of (Embodiment 1), in comparison to (Embodiment 2) and (Comparison Example 2) described above, the concentration of the reaction gas provided to the surface of the wafer W is high throughout approximately all the area just under the gas injector  31 . This is considered to be because, since, as described with reference to  FIG. 8 , for example, the reaction gas exiting the gas discharge opening  316  of the gas injector  31  is provided toward the wafer W approximately perpendicularly, the reaction gas is provided such that the reaction gas is not easily caused to fly upward by the N 2  gas flowing around, in comparison to (Embodiment 2) and (Comparison Example 2) in which the reaction gas is provided at an angle. In this point, the gas injector  31  according to (Embodiment 1) can provide the reaction gas efficiently to the surface of the wafer W even with such a relatively small amount of providing the reaction gas as, for example, 100 sccm, and it is possible to improve a film deposition rate in comparison to the other examples. It is noted that, (Comparison Example 1) in which the gas outflow openings  93  are formed downward perpendicularly cannot simply be compared with (Embodiment 1) for the easiness of the reaction gas being caused to fly upward by the N 2  gas flowing around. However, as described below, (Comparison Example 1) causes the undulation phenomenon of the reaction gas provided to the surface of the wafer W, and thus, it can be said that the gas injector  31  according to (Embodiment 1) is superior in a viewpoint of forming a film with a uniform film thickness. 
     Next, also according to the simulation result of (Embodiment 2) indicated by the thin solid line in  FIG. 21 , such a large undulation phenomenon appearing in (Comparison Example 1) described above did not appear in the reaction gas concentration distribution provided to the surface of the wafer W. On the other hand, in the reaction gas concentration distribution, such a phenomenon the same as that of (Embodiment 1) that the reaction gas concentration gently decreases in an ever-decreasing manner from the center side through the periphery side of the turntable  2  appeared. The phenomenon is considered to be because of, as discussed above for (Embodiment 1), a difference in a transportation distance per unit time of the turntable  2  between the center side and the periphery side, or a position of the evacuation opening  61 , and it is possible to adjust the reaction gas concentration distribution to be uniform by increasing intervals of the gas outflow openings  313  by sealing some of the gas outflow openings  313  by means of the seals  318  or such, or so. 
     Further, the reaction gas concentration provided to the surface of the wafer W is lower than that of (Embodiment 1) and higher than (Comparison Example 2) throughout approximately all the area just under the gas injector  31   a . This is considered to be because, as described above with reference to  FIG. 12  for example, since the reaction gas is provided to the processing zone P 1  with an oblique inclination to a direction in which the gas discharge opening  316  faces, a difference occurs from whether the reaction gas is easily caused to fly upward by a flow of the N 2  gas. Therefore, in comparison to (Embodiment 1) in which the reaction gas is provided perpendicularly, (Embodiment 2) is such that the reaction gas is easily caused to fly upward by the flow of the N 2  gas. In comparison to (Comparison Example 2) in which the reaction gas is provided laterally, (Embodiment 2) is such that the reaction gas is not easily caused to fly upward by the flow of the N 2  gas. 
     In comparison to the above-discussed respective embodiments, according to the simulation result of (Comparison Example 1) indicated by the broken line in  FIG. 21 , the undulation phenomenon is observed in which, the reaction gas concentration provided to the surface of the wafer W just under the reaction gas nozzle  91  changes significantly in a saw-tooth manner in the range of concentration from several % through ten and several % with respect to the abscissa axis of  FIG. 21 . In this concentration distribution, a position at which the reaction gas concentration has a local maximum corresponds to a position at which each gas outflow opening  93  is disposed on the reaction gas nozzle  91 , which supports the idea that the reaction gas concentration distribution is such that the gas outflow openings  93  are easily reflected. Further, also in a result of an experiment that was carried out separately, it was observed that unevenness occurred corresponding to positions of disposing the gas outflow openings  93  in a film formed by using the gas outflow openings  93  the same as those of (Comparison Example 1). 
     Next, according to the simulation result of (Comparison Example 2) indicated by the dashed line, since the direction of blowing out the reaction gas is a lateral direction, the reaction gas concentration undulation phenomenon observed in (Comparison Example 1) is not observed. However, the reaction gas concentration provided to the surface of the wafer W in (Comparison Example 2) is lower than that of any one of (Embodiment 1) and (Embodiment 2). This is considered to be because, since the direction of blowing out the reaction gas is the lateral direction, the reaction gas is such that the reaction gas is most easily caused to fly upward by a flow of the N 2  gas, and, a method of providing the reaction gas according to (Comparison Example 2) can be deemed as being such that a film deposition rate is low in comparison to these embodiments, 
     From the result of thus studying, it can be deemed that, also as can be seen from the simulation results of (Embodiment 1) and (Embodiment 2), the gas injectors  31  and  31   a  according to the modes for carrying out the embodiments of the present invention in which the reaction gas discharged by the gas outflow openings  313  is made to hit the guide member  315  provided at a position to face toward the gas outflow openings  313 , and then, is provided to the processing zone P 1  can form a film having a uniform film thickness in comparison to the reaction gas nozzles  91  and  92  according to (Comparison Example 1) and (Comparison Example 2), and also, can improve a film deposition rate in comparison to (Comparison Example 2). 
     The present invention is not limited to the above-described embodiments, and variations and modifications may be made without departing from the scope of the invention.