Patent Publication Number: US-2023160066-A1

Title: Gas supply assembly, substrate processing apparatus, nozzle, method of processing substrate, method of manufacturing semiconductor device, and recording medium

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a bypass continuation application of PCT International Application No. PCT/JP2021/033442, filed on Sep. 13, 2021, in the WIPO, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     Field 
     The present disclosure relates to a substrate processing apparatus, a gas supply assembly, a substrate processing method, and a method for manufacturing a semiconductor device. 
     Description of the Related Art 
     As one of the substrate processing apparatuses, there is a batch type substrate processing apparatus that processes a predetermined number of substrates at a time. Furthermore, as one of the batch type substrate processing apparatuses, there is a vertical substrate processing apparatus including a vertical processing furnace. In order to introduce a processing gas into a quartz reaction tube constituting the processing furnace, a plurality of gas supply nozzles erected along an inner wall of the reaction tube is used. The gas supply nozzles are supported by a nozzle support member. 
     SUMMARY 
     Since the gas supply nozzle made of quartz and the nozzle support member made of metal are fitted to each other, a slight gap may be formed between the quartz and the metal. Any gas other than the processing gas mixed into the nozzle through the gap causes generation of particles due to reaction, and the particles may fall onto a substrate along with a flow of the processing gas. Furthermore, direct contact between the quartz and the metal may cause generation of particles due to rubbing between the quartz and the metal, or breakage of the nozzle. 
     According to the present disclosure, there is provided a technique capable of preventing generation of particles due to a nozzle, particularly a connection structure between the nozzle and a nozzle adapter. 
     An aspect of the present disclosure provides a technique including: a nozzle that has an attaching portion formed on one end and discharges, into a processing chamber, a gas supplied to the attaching portion; a nozzle adapter that is disposed in the processing chamber and is clearance-fitted to an outer peripheral surface of the attaching portion with a predetermined gap; and a plurality of annular buffer members that is disposed in the attaching portion and abuts on the nozzle adapter, in which at least one of the annular buffer members is compressed and deformed in a radial direction of the corresponding annular buffer member in a state where the attaching portion of the nozzle is attached to the nozzle adapter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic oblique perspective view of a substrate processing apparatus suitably used in an embodiment of the present disclosure. 
         FIG.  2    is a diagram for explaining connection among a processing gas transfer pipe, a nozzle adapter, and a nozzle. 
         FIG.  3    is a perspective view for explaining a state where a nozzle is inserted into a nozzle adapter. 
         FIG.  4    is a cross-sectional view for explaining a state where a nozzle is inserted into a nozzle adapter. 
         FIG.  5    is a block diagram illustrating a schematic configuration of a controller of a substrate processing apparatus suitably used in an embodiment of the present disclosure. 
         FIG.  6    is a flowchart of a substrate processing step according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments will be described with reference to the drawings. Note that, in the following description, the same components are denoted by the same reference numerals, and repeated description may be omitted. Note that, in order to make description clearer, the drawings may be schematically illustrated as compared with an actual aspect. However, the illustration is only an example and does not limit construe of the present disclosure. A dimensional relationship among elements, a ratio among the elements, and the like illustrated in the drawings do not necessarily coincide with actual ones. In addition, a dimensional relationship among elements, a ratio among the elements, and the like do not necessarily coincide among the plurality of drawings. 
     Embodiment 
     (Configuration of Substrate Processing Apparatus) 
     A substrate processing apparatus  400  will be described with reference to  FIG.  1   .  FIG.  1    is a vertical cross-sectional view illustrating a configuration example of a substrate processing apparatus according to an embodiment of the present disclosure. 
     The substrate processing apparatus  400  includes a reaction tube  401 . The reaction tube  401  is made of a heat-resistant non-metallic material such as quartz (SiO2) or silicon carbide (SiC) and is formed in a cylindrical shape with an upper end closed and a lower end opened. The lower end of the reaction tube  401  is supported by a manifold  405  via an O-ring  414 . A space formed inside the reaction tube  401  and the manifold  405  is referred to as a processing space  402 . The reaction tube  401  and the manifold  405  are collectively referred to as a processing chamber. 
     A furnace opening is formed in the manifold  405 . The furnace opening is an entrance/exit through which the substrate support  30  passes when the substrate support  30  is inserted into the processing space  402 . The manifold, the furnace opening, and the like are collectively referred to as a furnace opening portion. 
     The processing space  402  is configured such that wafers (semiconductor substrates)  14  supported in a horizontal attitude by the substrate support  30  are accommodated in a state of being aligned in multiple stages in the vertical direction in the processing space  402 . The substrate support  30  accommodated in the processing space  402  is configured to be rotatable in a state where the plurality of wafers  14  is mounted on the substrate support  30  while maintaining airtightness in the processing space  402  by rotating a rotation shaft  404  by a rotation mechanism  403 . 
     The manifold  405  is disposed below the reaction tube  401  concentrically with the reaction tube  401 . The manifold  405  is made of a metallic material such as stainless steel, and has a cylindrical shape with an upper end and a lower end opened. The reaction tube  401  is vertically supported from a lower end side by this manifold  405 . That is, the reaction tube  401  forming the processing space  402  stands in the vertical direction via the manifold  405 . 
     The furnace opening is configured to be airtightly sealed by a seal cap  406  when a boat elevator (not illustrated) rises. A sealing member  407  such as an O-ring for airtightly sealing an inside of the processing space  402  is disposed between a lower end of the manifold  405  and the seal cap  406 . 
     A nozzle  408  for injecting a processing gas, a purge gas, or the like into the processing space  402  and an exhauster  410  for exhausting a gas in the processing space  402  are connected to the manifold  405 . The exhauster  410  includes an exhaust pipe  410   a  and an auto pressure controller (APC)  410   b.    
     The nozzle  408  is a nozzle (injector) that discharges a gas into the processing chamber, and extends in an arrangement direction of the plurality of wafers loaded into the processing chamber. A plurality of gas supply holes is formed on a downstream side of the substrate processing apparatus nozzle  408 , and an inside of the nozzle  408  is configured to be communicate with the reaction tube  401 . The processing gas and the like are supplied from the gas supply holes to the processing space  402 . The nozzle  408  is made of a non-metallic material having heat resistance, such as quartz (SiO2) or silicon carbide (SiC). 
     For example, two nozzles  408  are disposed. In this case, one nozzle is a first nozzle  408   a  that supplies a source gas, and the other nozzle is a second nozzle  408   b  that supplies a reactant gas that reacts with the source gas. Note that, here, the two supply pipes have been described, but the present disclosure is not limited thereto, and three or more supply pipes may be used depending on the type of process. 
     The nozzle  408  is connected to a processing gas transfer pipe  409  on an upstream side. The processing gas transfer pipe  409  transfers a gas from a gas source or the like to the nozzle  408 . A first processing gas transfer pipe  409   a  is connected to the first nozzle  408   a , and a second processing gas transfer pipe  409   b  is connected to the second nozzle  408   b . A connection structure between the nozzle  408  and the processing gas transfer pipe  409  is a connection configuration as described with reference to  FIGS.  2  to  4   . 
     An inert gas transfer pipe  413  is connected to the processing gas transfer pipe  409 . The inert gas transfer pipe  413  supplies an inert gas to the processing gas transfer pipe  409 . The inert gas is, for example, a nitrogen (N2) gas, and acts as a carrier gas of the processing gas or as a purge gas of the reaction tube  401 , the nozzle  408 , or the processing gas transfer pipe  409 . 
     A first inert gas transfer pipe  413   a  is connected to the first processing gas transfer pipe  409   a , and a second inert gas transfer pipe  413   b  is connected to the second processing gas transfer pipe  409   b.    
     In the processing gas transfer pipe  409 , a mass flow controller  431  and a valve  432  that control a supply amount of the processing gas are disposed. In the first processing gas transfer pipe  409   a , a mass flow controller  431   a  and a valve  432   a  are disposed. In the second processing gas transfer pipe  409   b , a mass flow controller  431   b  and a valve  432   b  are disposed. The mass flow controller  431  and the valve  432  are collectively referred to as a processing gas supply controller. 
     In the inert gas transfer pipe  413 , a mass flow controller  433  and a valve  434  that control a supply amount of the inert gas are disposed. In the first inert gas transfer pipe  413   a , a mass flow controller  433   a  and a valve  434   a  are disposed. In the second inert gas transfer pipe  413   b , a mass flow controller  433   b  and a valve  434   b  are disposed. The mass flow controller  433  and the valve  434  are collectively referred to as an inert gas supply controller. 
     The processing gas supply controller and the inert gas supply controller are collectively referred to as a gas supply controller. 
     A heater  411  serving as a heating means (heating mechanism) is disposed on an outer periphery of the reaction tube  401  concentrically with the reaction tube  401 . The heater  411  is configured to heat an atmosphere in the processing space  402  such that an inside of the processing space  402  has a uniform or predetermined temperature distribution. The heater  411  is supported by a heater base (not illustrated). 
     A furnace opening box (scavenger)  412  for safely guiding a leaked gas to an exhaust passage is disposed on an outer periphery of the manifold  405 . 
     Next, a connection configuration between the processing gas transfer pipe  409  and the nozzle  408  will be described with reference to  FIGS.  2  to  4   .  FIG.  2    is a diagram for explaining connections among the processing gas transfer pipe  409 , a nozzle adapter  500 , and the nozzle  408 . 
     As illustrated in  FIG.  2   , the processing gas transfer pipe  409  and the nozzle  408  are configured to be connected to each other via the L-shaped metal nozzle adapter  500 . In a state where the processing gas transfer pipe  409  and the nozzle  408  are assembled to the nozzle adapter  500 , a gas supplied to the processing gas transfer pipe  409  is supplied to the nozzle  408  through a pipe-shaped passage formed in the nozzle adapter  500 , and is discharged into the processing chamber from a plurality of gas supply holes  408   h  formed in the nozzle  408 . 
     The nozzle adapter  500  has a first adapter portion  501  which extends in the horizontal direction (first direction X) and to which the processing gas transfer pipe  409  is attached, and a second adapter portion  502  which is connected to the first adapter portion  501  and extends in the vertical direction (second direction Y) and to which the nozzle  408  is attached. The nozzle adapter  500  is also referred to as a metal port. The first adapter portion  501  is attached to an inlet port penetrating a side surface of the manifold  405 , and a portion of the first adapter portion  501  in the vicinity of the second adapter portion  502  and the second adapter portion  502  are disposed in the processing chamber. A surface of the nozzle adapter  500  may be mirror-finished by electrolytic composite polishing. 
     The entire nozzle  408  is formed in a pipe, and discharges a gas from the gas supply holes  408   h  at substantially a right angle to a longitudinal direction (wafer arrangement direction). Note that the term “substantially right angle” includes a range of error occurring in manufacturing, and is, for example, 90 degrees±10 degrees. The nozzle  408  has an attaching portion  408   p  as an attacher formed in a straight pipe shape at one end thereof, and the attaching portion  408   p  is configured to be inserted into the second adapter portion  502 . In the attaching portion  408   p , two annular buffer members  510  and  511  are disposed at different positions in a longitudinal direction. The two annular buffer members  510  and  511  are disposed in close contact with an outer periphery of the attaching portion  408   p , and are disposed so as to abut on the nozzle adapter  500 . As the annular buffer members  510  and  511 , for example, a ring-shaped fluorocarbon resin rubber (O-ring) having chemical resistance and heat resistance can be used. The O-ring can be molded using a polytetrafluoroethylene (PTFE)-based material with different physical properties such that stickiness, adhesiveness, or thermoplasticity is enhanced on an inner peripheral side abutting on the attaching portion  408   p  rather than an outer peripheral side abutting on the nozzle adapter  500 . The nozzle  408 , the nozzle adapter  500 , and accessories thereof are collectively referred to as a gas supply assembly. 
       FIG.  3    is a perspective view illustrating a state where the attaching portion  408   p  of the nozzle  408  is inserted into the second adapter portion  502 . In the second adapter portion  502 , an opening  503  is formed. In the attaching portion  408   p , a cutout portion  4084  is formed, and the nozzle  408  is inserted into the second adapter portion  502  such that the opening  503  and the cutout portion  4084  coincide with each other. The cutout portion  4084  is formed so as to make a direction of the nozzle  408  correct. 
     The opening  503  and the cutout portion  4084  are fixed by a semicircular metal block portion (also referred to as a fixing holder)  520  from a side surface side of the nozzle adapter  500 . As a result, the direction of the nozzle  408  is adjustable, and a direction of a gas discharged from the plurality of gas supply holes  408   h  into the processing chamber is accurately adjusted. An outer side of the block portion  520  is fixed using a thin semicircular ring-shaped metal plate portion (also referred to as a ring holder)  530 . 
       FIG.  4    is a cross-sectional view illustrating a state where the attaching portion  408   p  of the nozzle  408  is inserted into the second adapter portion  502 . 
     The attaching portion  408   p  is formed in a circular pipe having a constant outer diameter. The second adapter portion  502  of the nozzle adapter  500  has an insertion area  5021  having a hole portion with a constant inner diameter L 1  into which the attaching portion  408   p  is inserted, and a connection area  5022  disposed below the insertion area  5021  and having an opening with a diameter L 2  narrower than the diameter L 1 . The diameter L 1  is larger than the outer diameter of the attaching portion  408   p , and the diameter L 2  is preferably equal to the inner diameter of the attaching portion  408   p.    
     In the attaching portion  408   p , two angular U-shaped grooves  4081  and  4082  are formed on an outer peripheral surface  408   o  near both ends of the attaching portion  408   p  in the vertical direction (second direction Y). The two annular buffer members  510  and  511  are fitted into the two U-shaped grooves  4081  and  4082 , respectively. Radially inner sides of the annular buffer members  510  and  511  are disposed in close contact with bottom portions of the U-shaped grooves  4081  and  4082 , respectively. Radially outer sides of the annular buffer members  510  and  511  protrude from the U-shaped grooves  4081  and  4082 , respectively, and abut on an inner peripheral surface  502   i  of the second adapter portion  502  of the nozzle adapter  500 . At least one of the annular buffer members  510  and  511  is compressed and deformed in a radial direction of the corresponding annular buffer member ( 510  or  511 ) in a state where the attaching portion  408   p  of the nozzle  408  is attached to the second adapter portion  502  of the nozzle adapter  500 . 
     In this manner, the outer peripheral surface  408   o  of the attaching portion  408   p  and the inner peripheral surface  502   i  of the second adapter portion  502  are clearance-fitted to each other with a predetermined gap d 1 . Each of the annular buffer member  510  and  511  is disposed so as to separate the outer peripheral surface  408   o  of the attaching portion  408   p  and the inner peripheral surface  502   i  of the second adapter portion  502  from each other by a predetermined amount (here, d 1 ) to prevent the nozzle adapter  500  and the attaching portion  408   p  from coming into contact with each other. 
     A bottom surface  502   e  of the insertion area  5021  is formed flat at a boundary between the insertion area  5021  and the connection area  5022 . A lower end of the attaching portion  408   p  is formed flat, but a corner portion at an outer periphery is chamfered, and a tapered surface  4083  is formed. An annular buffer member  512  is disposed between the bottom surface  502   e  and the tapered surface  4083 . As the annular buffer member  512 , for example, a ring-shaped fluorocarbon resin rubber (O-ring) having chemical resistance and heat resistance can be used. The annular buffer member  512  is disposed between the bottom surface portion  408   e  formed at the lower end of the attaching portion  408   p  and the bottom surface  502   e  of the insertion area  5021  so as to maintain a predetermined gap d 2 . 
     In this manner, the annular buffer member  512  is disposed on the bottom surface  502   e  such that the bottom surface portion  408   e  of the attaching portion  408   p  and the bottom surface  502   e  of the insertion area  5021  do not come into contact with each other in a state where the attaching portion  408   p  of the nozzle  408  is attached to the second adapter portion  502  of the nozzle adapter  500 . 
     Note that the connection area  5022  is connected to the first adapter portion  501  of the nozzle adapter  500 . A flow path bent at a right angle is formed inside the connection area  5022 , and one end of the flow path opens to the insertion area  5021  and the other end communicates with a flow path of the first adapter portion  501 . 
     The cutout portion  4084  is formed between the U-shaped grooves  4081  and  4082  of the attaching portion  408   p , and the attaching portion  408   p  is attached to the second adapter portion  502  such that the opening  503  corresponds to the cutout portion  4084 . The opening  503  and the cutout portion  4084  are fixed by the block portion  520 . That is, movement and rotation in the vertical direction are restricted. 
     As described above, since the two annular buffer members  510  and  511  are disposed at an upper portion and a lower portion of the attaching portion  408   p , inclination of the quartz nozzle  408  can be prevented. The two annular buffer members disposed on the outer periphery of the attaching portion  408   p  are desirably disposed so as to be far away from each other as much as possible from a viewpoint of suppressing the inclination. Since the gas supply hole  408   h  injects a gas laterally, a reaction force of the injection is generated in a direction of inclining the nozzle  408 . However, even if the gas is supplied to the nozzle  408  in a pulse shape, the inclination and swing can be sufficiently suppressed. In addition, even if the gap d 1  is widened by a difference in coefficient of thermal expansion due to exposure to high temperature when the wafer is processed, the attaching portion  408   p  is pushed by the annular buffer members  510  and  511  with substantially the same force from all directions. Therefore, the attaching portion  408   p  can maintain an upright state. 
     As a result, it is possible to prevent direct contact between the metal of the second adapter portion  502  of the nozzle adapter  500  and the quartz of the nozzle  408  due to the inclination. Since direct contact can be prevented, generation of particles due to contact can be prevented. Furthermore, among the plurality of annular buffer members, the annular buffer members  511  and  512  disposed below the opening  503  can improve airtightness between the nozzle  408  and the nozzle adapter  500 . Note that the annular buffer member  512  is not essential from a viewpoint of preventing inclination. The number of particles generated by direct contact between the bottom surface portion  408   e  and the bottom surface  502   e  may be sufficiently small as to be allowable. The airtightness can be sufficiently maintained by the annular buffer member  511  alone. 
     (Controller) 
       FIG.  5    is a block diagram schematically illustrating a configuration example of a controller included in a substrate processing apparatus according to an embodiment of the present disclosure. The controller  260  is configured as a computer including a central processing unit (CPU)  260   a , a random access memory (RAM)  260   b , a memory  260   c , and an I/O port  260   d.    
     The RAM  260   b , the memory  260   c , and the I/O port  260   d  are configured to be capable of exchanging data with the CPU  260   a  via an internal bus  260   e . An input/output device  261  configured as, for example, a touch panel and an external memory  262  are configured to be connectable to the controller  260 . From the input/output device  261 , information can be input to the controller  260 . The input/output device  261  also displays and outputs information under control of the controller  260 . Furthermore, a network  263  is configured to be connectable to the controller  260  through a receiver  285 . This means that the controller  260  is also connectable to a host device  290  such as a host computer present on the network  263 . 
     The memory  260   c  is constituted by, for example, a flash memory or a hard disk drive (HDD). In the memory  260   c , a control program for controlling an operation of the substrate processing apparatus  400 , a process recipe describing procedures, conditions, and the like for substrate processing, calculation data, processing data, and the like generated in a process until setting a process recipe used for processing on the wafer  14 , and the like are stored in a readable manner. Note that the process recipe is a combination formed so as to cause the controller  260  to execute procedures in a substrate processing step to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, and the like are also collectively and simply referred to as a program. Note that, in the present specification, the term “program” may include only a process recipe alone, only a control program alone, or both of these. The RAM  260   b  is configured as a memory area (work area) in which a program, calculation data, processing data, and the like read by the CPU  260   a  are temporarily stored. 
     The CPU  260   a  serving as a calculator is configured to read and execute a control program from the memory  260   c , and to read a process recipe from the memory  260   c  in response to input of an operation command from the input/output device  261 , or the like. In addition, the CPU  260   a  is configured to compare and calculate a set value input from the receiver  285  with the process recipe and the control data stored in the memory  260   c  to be able to calculate calculation data. In addition, the CPU  260   a  is configured to be able to execute determination processing and the like of corresponding processing data (process recipe) from the calculation data. In addition, the CPU  260   a  is configured to perform operation control on each of the units in the substrate processing apparatus  10  in accordance with the content of the read process recipe. 
     Note that the controller  260  is not limited to a configuration as a dedicated computer, and may be configured as a general-purpose computer. For example, the controller  260  according to the present embodiment can be configured by preparing an external memory (for example, a magnetic tape, a magnetic disk such as a flexible disk or a hard disk, an optical disk such as a CD or a DVD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory or a memory card)  262  storing the above-described program, and installing the program in a general-purpose computer using the external memory  262 . Note that the means for supplying the program to the computer is not limited to the supply via the external memory  262 . For example, the program may be supplied using a communication means such as the network  263  (the Internet or a dedicated line) without going through the external memory  262 . Note that the memory  260   c  and the external memory  262  are configured as computer-readable recording media. Hereinafter, these are also collectively referred to simply as a recording medium. Note that, in the present specification, the term “recording medium” may include only the memory  260   c  alone, only the external memory  262  alone, or both of these. 
     (Substrate Processing Step) 
     A substrate processing step according to an embodiment of the present disclosure will be described with reference to  FIG.  6   . Note that the substrate processing step according to the present embodiment is a method for forming a film on a surface of the wafer  14  using, for example, a chemical vapor deposition (CVD) method, and is performed as one step of a process for manufacturing a semiconductor device. Note that, in the following description, an operation of each of the units constituting the substrate processing apparatus is controlled by the controller  260 . 
     In a substrate loading step S 901 , the plurality of wafers  14  is loaded into the substrate support  30  (wafer charge). Then, the substrate support  30  supporting the plurality of wafers  14  is lifted by a boat elevator (not illustrated) and loaded into the processing space  402  (boat loading). In this state, the seal cap  406  seals a lower end of the manifold  405  via the O-ring  407 . 
     Subsequently, in a pressure adjusting step S 902 , the atmosphere in the processing space  402  is exhausted from the exhauster  410  such that an inside of the processing space  402  has a desired pressure (degree of vacuum). At this time, the pressure in the processing space  402  is measured, and the degree of opening of the APC valve  410   b  disposed in the exhauster  410  is feedback-controlled based on the measured pressure. The pressure adjusting step S 902  is continued until a film forming step S 904  is completed. 
     Subsequently, in a temperature adjusting step S 903 , the inside of the processing space  402  is heated by the heater  411  to a desired temperature. At this time, the degree of energization to the heater  411  is feedback-controlled based on temperature information detected by a temperature sensor such that the inside of the processing space  402  has a predetermined temperature distribution. Then, the substrate support  30  is rotated by the rotation mechanism  403  to rotate the wafers  14 . The temperature adjusting step S 903  is continued until the film forming step S 904  is completed. Either the temperature adjusting step S 903  or the pressure adjusting step S 902  may be started first. 
     Subsequently, in the film forming step S 904 , a gas is supplied onto each of the wafers  14  to form a desired film. For example, a silicon source gas serving as a first processing gas from the first nozzle  408   a  and a nitrogen source gas serving as a second processing gas from the second nozzle  408   b  are supplied continuously or alternately. The silicon source gas and the nitrogen source gas supplied to the processing space  402  react with each other in a gas phase or on a surface of each of the wafers  14  to form a silicon nitride film on each of the wafers  14 . At this time, the gas flows in each of the first nozzle  408   a  and the second nozzle  408   b  at a speed close to the sound speed, and a static pressure therein can be lower than that in the processing space  402 . 
     Subsequently, in a temperature lowering step S 905 , the temperature adjustment in step S 903  continued during the film forming processing is stopped or reset to a lower temperature as necessary, and the temperature in the processing chamber  201  is gradually lowered. 
     Subsequently, in a vent and atmospheric pressure returning step S 906 , the degree of opening of the APC valve  410   b  is reduced or fully closed, and a purge gas is supplied into the processing space  402  until the pressure in the processing space  402  reaches the atmospheric pressure. The purge gas is, for example, an N2 gas, and can be supplied to the processing space via the inert gas transfer pipes  413   a  and  413   b . Note that this step S 906  may be started immediately after the film forming step S 904  is completed. The temperature lowering step S 905  and the vent and atmospheric pressure returning step S 906  may be performed in parallel, or the starting order may be changed. 
     Finally, in a substrate unloading step S 907 , the wafer  14  on which the film has been formed is unloaded from the inside of the processing space  402  by a procedure reverse to the substrate loading step S 901 . 
     According to the present embodiment, the following one or more effects can be obtained. 
     (1) The substrate processing apparatus  400  includes two annular buffer members (O-rings)  510  and  511  disposed in close contact with an outer periphery of the attaching portion  408   p  and abutting on the nozzle adapter  500 . As a result, it is possible to prevent the outer peripheral surface of the nozzle  408  serving as a nozzle from coming into direct contact with the metal nozzle adapter  500 , and to prevent generation of particles due to the contact. At the same time, airtightness between the nozzle  408  and the metal nozzle adapter  500  is improved, and mixing of impurities from the outside of the nozzle  408  and leakage from the inside of the nozzle  408  can be suppressed. 
     (2) Since the nozzle adapter  500  is attached to the nozzle  408  by hand in a state where the nozzle  408  is stably held outside the processing chamber, a large force is not applied to the attaching portion  408   p , and there is little possibility that the outer peripheral surface of the nozzle  408  and the nozzle adapter  500  come into contact with each other during the attachment and that particles are generated due to the contact. 
     (3) Coating may be applied to the surface of the quartz nozzle  408 , but the effect of suppressing contact between the outer peripheral surface of the nozzle  408  and the inner peripheral surface of the nozzle adapter  500  and the effect of suppressing generation of particles are not reduced due to appropriate elasticity and adhesion of the annular buffer members  510 ,  511 , and  512  even if the surface roughness of the coating is rougher than that of a normal fired quartz surface. 
     (4) Since the conventional nozzle is merely pressed against the nozzle adapter  500  by its own weight, the nozzle slightly moves up and down (in the axial direction) due to a relationship between the pressure in the processing chamber and the gas pressure in the nozzle particularly when a gas is intermittently supplied, and particles may be generated even during the processing in the substrate processing step. Since the annular buffer members  510 ,  511  and  512  are disposed, the vertical (axial) movement is suppressed, and even if the movement occurs, direct contact between the outer peripheral surface of the nozzle  408  and the metal nozzle adapter  500  and a gas flow can be prevented, and generation of particles can be prevented. 
     (5) When the nozzle  408  is inserted into the nozzle adapter  500 , only the annular buffer members  510  and  511  and the nozzle adapter come into contact with each other, friction is small, and attachment can be easily performed. In addition, vertical movement is suppressed by appropriate friction, and therefore it is possible to prevent the nozzle  408  from being accidentally dropped. 
     Although specific description has been made above based on Examples, the present disclosure is not limited to the above embodiments and Examples, and it goes without saying that various modifications can be made. For example, the angular U-shaped grooves  4081  and  4082  includes dovetail grooves and are not limited to those formed in the nozzle  408 , and may be formed in the nozzle adapter  500 . 
     According to the above technique, since the annular buffer member is disposed, it is possible to suppress generation of particles derived from the nozzle.