Patent Publication Number: US-2023144886-A1

Title: Method of manufacturing semiconductor device, method of managing parts, and recording medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application is a continuation of U.S. Pat. Application No. 16/451,507, filed Jun. 25, 2019 and claims the benefit of priority from Japanese Patent Application Nos. 2018-121147 and 2019-094748, filed on Jun. 26, 2018 and May 20, 2019, respectively, the entire contents of which are incorporated herein by references. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a method of manufacturing a semiconductor device, a method of manufacturing parts, and a recording medium. 
     BACKGROUND 
     There have been developed a substrate processing apparatus for manufacturing a semiconductor device by forming a thin film on a substrate such as a silicon wafer, and a method of manufacturing the semiconductor device. 
     As one type of this substrate processing apparatus, there is a semiconductor manufacturing apparatus that executes one process of manufacturing a semiconductor device (hereinafter referred to as a substrate-processing process). In a substrate processing apparatus as the semiconductor manufacturing apparatus, for example, a SiN film is formed over a substrate (hereinafter also referred to as a wafer) with a DCS gas and an NH 3  gas. 
     Particularly, in a vertical semiconductor manufacturing apparatus in which a gas is charged into a tank and then blown out, it is known that the film formation result fluctuates depending on a Cv value (a so-called capacity coefficient which is a value indicating the volume of fluid flowing through a valve at a differential pressure across the fluid) of a valve at the subsequent stage (downstream) of the tank, and so a valve whose Cv value is strictly measured may be used. However, the Cv value may fluctuate depending on the number of times of opening/closing of the valve or due to other disturbances such as valve temperature fluctuation, which may affect the film formation result. 
     Further, even when the valve Cv value in the initial state is the same, the Cv value may fluctuate due to a difference in the device environment, and therefore, matching between the film thickness and uniformity of a plurality of devices may become problematic. 
     SUMMARY 
     Some embodiments of the present disclosure provide a technique capable of preventing occurrence of product lot-out due to fluctuation of a valve characteristic value even when the characteristic value fluctuates due to long-term operation or external factors. 
     According to one or more embodiments of the present disclosure, there is provided a technique that includes executing a process recipe for processing a substrate by supplying a process gas into a process furnace; and executing a correction recipe for checking a characteristic value of a supply valve installed at a process gas supply line for supplying the process gas into the process furnace, wherein the act of executing the correction recipe comprises: supplying an inert gas into the process gas supply line for a certain period of time in a state where an adjusting valve that is installed at an exhaust portion of the process furnace and adjusts an internal pressure of the process furnace is fully opened; detecting a pressure value in a supply pipe provided with the supply valve while supplying the inert gas into the process gas supply line in the state where the adjusting valve is fully opened; and calculating the characteristic value of the supply valve based on the detected pressure value. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a longitudinal sectional view schematically showing a vertical process furnace of a substrate processing apparatus according to embodiments of the present disclosure. 
         FIG.  2    is a schematic cross-sectional view taken along line A-A in  FIG.  1   . 
         FIG.  3    is a schematic view showing a portion of the substrate processing apparatus according to the present embodiments. 
         FIG.  4    is a schematic configuration view of a controller of the substrate processing apparatus according to the present embodiments, in which a control system of the controller is shown in a block diagram. 
         FIG.  5    is an explanatory view showing an outline of a correction recipe for check of a Cv value according to the present embodiments. 
         FIG.  6    shows an example of the check result of the Cv value according to the present embodiments,  FIG.  6 A  being an explanatory view showing an example of the check result of a Cv value of a valve heater A, and  FIG.  6 B  being an explanatory view showing an example of the check result of a Cv value of a valve heater B. 
         FIG.  7    is a schematic explanatory view showing Cv value checking according to the present embodiments,  FIG.  7 A  being a longitudinal sectional view of a valve heater A in which the temperature measurement position is set to a position away from the valve, and  FIG.  7 B  being a longitudinal sectional view of a valve heater B in which the temperature measurement position is set to a position inside the valve. 
         FIG.  8    is an explanatory view in which film thickness data in the check result of  FIG.  7    are displayed with a line graph. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1  and  2    show a vertical process furnace  29  used in a substrate processing apparatus which is an example of a processing apparatus according to the present disclosure. 
     First, an outline of the operation of the substrate processing apparatus according to the present disclosure will be described with reference to  FIG.  1   . 
     When a predetermined number of wafers  31  as workpieces are transferred in a boat  32  as a holder, the boat  32  is raised by a boat elevator and is inserted into the process furnace  29 . In a state where the boat  32  is completely charged, the process furnace  29  is air-tightly closed by a seal cap  35 . In the air-tightly closed process furnace  29 , in accordance with a selected process recipe, the wafers  31  are heated, a process gas is supplied into the process furnace  29 , and the wafers  31  are processed while the atmosphere of the process chamber  2  is being discharged from a gas exhaust pipe  66  by an exhaust device (not shown). 
     Next, the process furnace  29  will be described with reference to  FIGS.  1  and  2   . 
     A reaction tube  1  is installed inside a heater  42  which is a heating device (heating means), and a manifold  44  is connected consecutively to the lower end of the reaction tube  1 , for example, by stainless steel via an O-ring  46  which is an airtight member. The lower end opening (furnace port) of the manifold  44  is air-tightly closed by the seal cap  35  as a lid via an O-ring  18  which is an airtight member. Thus, the process chamber  2  is defined by at least the reaction tube  1 , the manifold  44 , and the seal cap  35 . 
     The boat  32  is erected over the seal cap  35  via a boat support  45 , and the boat support  45  serves as a holder for holding the boat  32 . 
     Two gas supply pipes (a first gas supply pipe  47  and a second gas supply pipe  48 ) as supply paths for supplying a plurality of types of process gases, here, two types of process gases, are installed in the process chamber  2 . 
     A precursor unit  71 , a valve  81 , a first mass flow controller (hereinafter also referred to as an MFC)  49 , which is a liquid flow rate control device (flow rate control means), a valve  82 , a reservoir  51  as a tank, and a valve  52 , which is an opening/closing valve, are arranged in the first gas supply pipe  47  in this order from the upstream. A pressure gauge  80  as a pressure sensor and a valve  84  are installed between the valve  82  and the reservoir  51 . In particular, a first carrier gas supply pipe  53  for supplying a carrier gas is joined at the downstream side of the valve  52  as a gas supply valve. A carrier gas source  72 , a second MFC  54  which is a flow rate control device (flow rate control means), and a valve  55 , which is an opening/closing valve, are arranged in the first carrier gas supply pipe  53  in this order from the upstream. Further, a first nozzle  56  extending vertically along the inner wall of the reaction tube  1  is installed at a leading end of the first gas supply pipe  47 , and first gas supply holes  57  for supplying a gas are formed in the side of the first nozzle  56 . The first gas supply holes  57  are formed at equal pitches in the vertical direction and have the same opening area. A carrier gas (for example, a N 2  gas), which is an inert gas supplied from the carrier gas source  72 , can be supplied to a supply pipe  47   a  between the precursor unit  71  and the valve  81  via a valve  77  by a supply pipe  76 . 
     Further, in the present embodiments, although not particularly illustrated, a vaporizer is installed. The vaporizer includes the first MFC  49 , the reservoir  51  including a tank for storing a liquid precursor, and a heater for heating the liquid precursor. The heater (not shown) is installed in the reservoir  51  and is used to vaporize the liquid precursor. In the present embodiments, the valve  52  is also provided with a valve heater (hereinafter also simply referred to as a heater), which will be described below, as an example of a heating member. 
     In the description of the present embodiments, in the first gas supply pipe  47 , a pipe provided at the upstream side of the reservoir  51  between the reservoir  51  and the precursor unit  71  is referred to as a supply pipe  47   a . Further, in the first gas supply pipe  47 , the downstream side of the reservoir  51  is referred to as a supply pipe  47   b . 
       FIG.  3    is an enlarged view of a main part of the supply pipe  47   a  for supplying a dichlorosilane (SiH 2 Cl 2 , abbreviation: DCS) gas. As shown in  FIG.  3   , the supply pipe  47   a  for supplying the DCS gas is provided with a reservoir  51  as a tank for storing the DCS gas, valves  52 ,  82  and  84  on the upstream side and the downstream side, and a pressure gauge  80 . When flowing the DCS gas in the reservoir  51  into the process furnace  29 , since the DCS gas does not flow smoothly if there is an unnecessary pipe, a pressure gauge  80  is attached to the upstream of the reservoir  51  as shown in  FIG.  3   . Parts of the pressure gauge  80  and the valve  84  will be described below. 
     Here, the first gas supply pipe  47 , the first MFC  49 , the reservoir  51 , the valve  52 , the valve  81  and the valve  82  are collectively referred to as a first gas supplier (first gas supply line). The nozzle  56  may be also included in the first gas supplier. The carrier gas supply pipe  53 , the second MFC  54  and the valve  55  may be also included in the first gas supplier. Further, the precursor unit  71  and the carrier gas source  72  may be also included in the first gas supplier. 
     A reaction gas source  73 , a third MFC  58 , which is a flow rate control device (flow rate control means), and a valve  59 , which is an opening/closing valve, are arranged in the second gas supply pipe  48  in this order from the upstream. A second carrier gas supply pipe  61  for supplying a carrier gas is joined at the downstream side of the valve  59 . A carrier gas source  74 , a fourth MFC  62 , which is a flow rate control device (flow rate control means), and a valve  63 , which is an opening/closing valve, are arranged in the second carrier gas supply pipe  61  in this order from the upstream. A second nozzle  64  is installed in parallel to the first nozzle  56  at a leading end of the second gas supply pipe  48 , and second gas supply holes  65  for supplying a gas are formed on the side of the second nozzle  64 . The second gas supply holes  65  are formed at equal pitches in the vertical direction and have the same opening area. 
     Here, the second gas supply pipe  48 , the third MFC  58 , the valve  59  and the nozzle  64  are collectively referred to as a second gas supplier (second gas supply line). The carrier gas supply pipe  61 , the fourth MFC  62  and the valve  63  may be also included in the second gas supplier. Further, the reaction gas source  73  and the carrier gas source  74  may be also included in the second gas supplier. 
     A liquid precursor supplied from the precursor unit  71  joins the first carrier gas supply pipe  53  via the valve  81 , the first MFC  49 , the valve  82 , the reservoir  51 , and the valve  52 , and is then supplied into the process chamber  2  via the first nozzle  56 . The liquid precursor is supplied into the process chamber  2  in a state where it is vaporized by a vaporizer (not shown). A reaction gas supplied from the reaction gas source  73  joins the second carrier gas supply pipe  61  via the third MFC  58  and the valve  59  and is then supplied into the process chamber  2  via the second nozzle  64 . 
     The process chamber  2  is connected to a vacuum pump  68 , which is an exhaust device (exhaust means), via a gas exhaust pipe  66  for exhausting a gas and is vacuum-exhausted by the vacuum pump  68 . Further, the gas exhaust pipe  66  is provided with a pressure sensor as a furnace pressure gauge and a valve  67  as a pressure control valve. The valve  67  is an opening/closing valve which can be opened/closed for vacuum-exhaust/stop of vacuum-exhaust of the process chamber  2 , and the valve  67  is an on-off valve that is adjustable to a predetermined pressure by adjusting the valve opening based on the pressure value detected by the pressure sensor. 
     A boat rotation mechanism  69  is installed on the seal cap  35 . The boat rotation mechanism  69  is configured to rotate the boat  32  to improve processing uniformity. 
     As shown in  FIG.  4   , the substrate processing apparatus includes a controller  41  that controls the operations of various parts. 
     The outline of the controller  41  is shown in  FIG.  4   . The controller  41 , which is a control part (control means), is configured as a computer including a central processing unit (CPU)  41   a , a random access memory (RAM)  41   b , a storage device  41   c , and an I/O port  41   d . The RAM  41   b , the storage device  41   c , and the I/O port  41   d  are configured to exchange data with the CPU  41   a  via an internal bus  41   e . The controller  41  is configured to be connected to an input/output device  411  configured as a touch panel, for example, and an external storage device  412 . Further, a receiver  413  connected to a host device  75  via a network is connected to the controller  41 . The receiver  413  can receive information of other devices from the host device  75 . 
     The storage device  41   c  is configured by, for example, a flash memory, a hard disk drive (HDD), or the like. A control program for controlling the operation of the substrate processing apparatus, a process recipe in which the procedure and condition of substrate processing to be described below are described, a correction recipe, and the like are stored readably in the storage device  41   c . The process recipe and the correction recipe are combined to obtain a predetermined result by causing the controller  41  to execute the respective procedures in the substrate-processing process and characteristic-checking process performed in a substrate processing mode, and function as a program. In the present disclosure, the term “program” may include only the process recipe or the correction recipe, only the control program, or both. Further, the RAM  41   b  is configured as a memory area (work area) in which programs, data, and the like read by the CPU  41   a  are temporarily held. 
     The I/O port  41   d  is connected to an elevating member, a heater, a mass flow controller, a valve, and the like. 
     The controller  41 , which is a control part, performs various controls on flow rate adjustment of the MFC, opening/closing operation of the valve, temperature adjustment of the heater, start-up/stop of the vacuum pump, rotational speed adjustment of the boat rotation mechanism, elevating operation of a boat elevation mechanism, operation of the pressure gauge  80 , and the like. 
     The controller  41  is not limited to the dedicated computer but may be configured as a general-purpose computer. For example, the controller  41  according to the embodiments can be configured by preparing the external storage device  412  (for example, a semiconductor memory such as a USB memory or a memory card) that stores the above-mentioned program and installing the program in a general-purpose computer using the external storage device  412 . The means for supplying the program to the computer is not limited to being supplied via the external storage device  412 . For example, a communication means such as Internet or a dedicated line may be used to supply the program without going through the external storage device  412 . Further, the storage device  41   c  and the external storage device  412  are configured as a computer-readable recording medium. Hereinafter, these are collectively referred to simply as a recording medium. In the present disclosure, when the term “recording medium” is used, it may include only the storage device  41   c , only the external storage device  412 , or both. 
     Next, an example of processing a substrate will be described. Here, as an example of a process of manufacturing a semiconductor device, a cycle process of processing a film by alternately supplying a source (precursor) and a reactant (reaction gas) to a process chamber will be described. In the embodiments, an example will be described in which a silicon nitride film (Si 3 N 4  film, hereinafter also referred to as a SiN film) is formed on a substrate using a DCS gas as the source and an ammonia (NH 3 ) gas as the reactant. DCS is an example of a liquid precursor. 
     In a film-forming process in the present embodiments, a SiN film is formed on a wafer  31  by performing a cycle a predetermined number of times (once or more), the cycle including non-simultaneously performing: step  1  of supplying a DCS gas to the wafer  31  of the process chamber  2 ; step  2  of removing the DCS gas (residual gas) from the process chamber  2 ; step  3  of supplying an NH 3  gas to the wafer  31  of the process chamber  2 ; and step  4  of removing the NH 3  gas (residual gas) from the process chamber  2 . 
     First, as described above, the wafer  31  is charged to the boat  32  which is then loaded into the process chamber  2 . At this time, as shown in  FIG.  2   , the reservoir  51  is connected to the precursor unit  71 . After the boat  32  is loaded into the process chamber  2 , four steps to be described below are sequentially executed 
     Step 1 
     In step 1, a DCS gas and a carrier gas are flown while the heater  42  is being operated. First, the valves  55 ,  67 ,  81 , and  82  are opened. The flow rate of the DCS gas is adjusted by the MFC  49  and the DCS gas is supplied from the supply pipe  47   a  to the reservoir  51  via a pipe. The DCS gas is stored in the tank of the reservoir  51  and is vaporized by a heater (not shown). The vaporized gaseous DCS gas is supplied to the supply pipe  47   b  by opening the valve  52  and closing the valve  81  and the valve  82 . The carrier gas whose flow rate is adjusted by the second MFC  54  is supplied from the first carrier gas supply pipe  53  to the supply pipe  47   b  and is mixed with the DCS gas in the supply pipe  47   b . This mixed gas is exhausted from the gas exhaust pipe  66  while being supplied into the process chamber  2  from the first gas supply holes  57  of the first nozzle  56 . Thus, a film containing Si is formed over the wafer  31 . 
     Step 2 
     In step 2, the valve  52  of the first gas supply pipe  47  and the valve  55  of the first carrier gas supply pipe  53  are closed to stop the supply of the DCS gas and the carrier gas. With the valve  67  of the gas exhaust pipe  66  kept open, the process furnace  29  is exhausted to 20 Pa or lower by the vacuum pump  68 , and the residual DCS gas is eliminated from the process chamber  2 . At this time, if an inert gas, for example, a N 2  gas used as a carrier gas, is supplied to the process furnace  29 , the effect of eliminating the residual DCS gas is further enhanced. 
     Step 3 
     In step 3, an NH 3  gas and a carrier gas are flown. First, the valve  59  installed in the second gas supply pipe  48  and the valve  63  installed in the second carrier gas supply pipe  61  are both opened to mix the NH 3  gas, with its flow rate adjusted by the third MFC  58 , supplied from the second gas supply pipe  48 , and the carrier gas, with its flow rate adjusted by the fourth MFC  62 , supplied from the carrier gas supply pipe  61 . This mixed gas is exhausted from the gas exhaust pipe  66  while being supplied from the second gas supply holes  65  of the second nozzle  64  into the process chamber  2 . By the supply of the NH 3  gas, the film containing Si over the base film of the wafer  31  reacts with the NH 3  gas to form a SiN film o the wafer  31 . 
     Step 4 
     In step 4, after the SiN film is formed, the valves  59  and  63  are closed, and the interior of the process chamber  2  is vacuumed-exhausted by the vacuum pump  68  to eliminate the NH 3  gas remaining after contributing to film formation. At this time, if an inert gas, for example, a N 2  gas used as a carrier gas, is supplied into the process chamber  2 , the effect of eliminating the residual NH 3  gas from the process chamber  2  is further enhanced. 
     Further, a SiN film having a predetermined film thickness can be formed over the wafer  31  by repeating one cycle plural times, the one cycle including the above-described steps 1 to 4. 
     As described above, in the process recipe, with the valves  81 ,  82  opened and the valves  52 ,  84  closed, the DCS gas is stored in the tank of the reservoir  51 . Thereafter, the valves  81  and  82  are closed and then the valve  52  is opened to flow the DCS gas in the tank of the reservoir  51  into the process chamber  2  of the reaction tube  1 . A film is formed by repeating this process for several hundred cycles. 
     At this time, a Cv value (so-called capacity coefficient) as a characteristic value of the valve  52  affects the flow rate and speed of the DCS gas and consequently the film thickness. 
     Next, a process of executing a correction recipe for checking the characteristic value (Cv value) of the valve  52  as parts to be managed in the embodiments will be described with reference to  FIG.  5   . By executing the correction recipe shown in  FIG.  5    for each batch, it is possible to check the fluctuation of the Cv value which is the capacity coefficient of the valve  52 ._Here, the pressure difference is the difference between the primary side (pressure gauge  80 ) and the secondary side (pressure sensor). However, in the embodiments, since the value of the pressure sensor provided in the gas exhaust pipe  66  is sufficiently small such as several tens Pa, it is set to zero in calculation. 
     Although a condition of the correction recipe shown in  FIG.  5    is different from a condition for actually processing the wafer  31 , since the Cv value fluctuates according to a measurement condition, it is necessary to fix a condition for measuring the Cv value. For this reason, as shown in  FIG.  1   , the pressure gauge  80  is installed at least in the supply pipe  47   a  on the upstream side of the valve  52  (preferably between the valve  52  and the valve  82 ), the valve  84  for isolating from the precursor gas supplied from the precursor unit  71  is installed, and an inert gas (N 2  gas) is supplied from the carrier gas source  72  to the supply pipe  47   a  on the upstream side of the valve  81 , as described above. With such a configuration, the correction recipe shown in  FIG.  5    can be implemented under predetermined fixed condition. 
     When the correction recipe shown in  FIG.  5    is executed, a predetermined standby state is checked, and the boat  32  is raised by the boat elevator without transferring the wafer  31  and is loaded into the process furnace  29  (boat-loading step). With the boat  32  loaded, the process furnace  29  is air-tightly closed by the seal cap  35 . In the air-tightly closed process furnace  29 , evacuation and N 2  purge are performed as the process recipe (purge step). Then, with the pressure adjusting valve  67  installed in the gas exhaust pipe  66  fully opened, a N 2  gas of a constant flow rate is supplied into the process furnace  29 , and the pressure value of the pressure gauge  80  is detected. Then, a calculation process is performed by an incorporated program to calculate a Cv value from the detected pressure value. If the Cv value is normal, as well as the process recipe, the internal atmosphere of the process furnace  29  is replaced with N 2  at the atmospheric pressure, the boat is unloaded from the process furnace  29 , and the process furnace  29  is returned to the standby state (boat-unloading step). Next, each step will be described. 
     First, in the process of the correction recipe shown in  FIG.  5   , as a first step, the internal temperature of the reaction tube  1  (the process chamber  2 ) is set to a temperature in the normal standby state. Then, the valves  55 ,  81 ,  82 ,  52 , and  67  are opened to perform the N 2  purge. That is, the residual DCS gas is eliminated by supplying a N 2  gas, which is an inert gas used as a carrier gas, to the process chamber  2 . In short, it is checked whether the process chamber  2  is in the normal standby state. 
     Next, as a second step, the boat  32  is loaded. This is because it is necessary to read a numerical value of the pressure gauge  80  when a determined N 2  gas is flown to a target valve (the valve  52 ) in a state where the interior of the process chamber  2  is evacuated, in order to measure a Cv value. At this time, the wafer  31  is not placed on the boat  32 . 
     Next, as a third step, with the valves  81 ,  82 ,  52 , and  84  closed, the process chamber  2  is evacuated by the vacuum pump  68  to evacuate the interior of the process furnace  29 . The evacuation may be checked in the same manner as the process recipe. Further, when this step is performed, the valves installed in the second gas supply line as well as the first gas supply line are closed as described above. 
     Next, as a fourth step, the valves  81 ,  82 ,  52 , and  84  in the first gas supply line are opened to perform N 2  purge. That is, a N 2  gas, which is an inert gas used as a carrier gas, is supplied to the process chamber  2 . Here, in this step, in order to remove outgassing and particles existing in the process furnace  29 , the N 2  purge is performed on all lines including the first gas supply line having the reservoir  51 . 
     Next, as a fifth step, the valves  81 ,  82 ,  52 ,  84 , and  67  are continuously opened to flow the N 2  gas into the first gas supply line after stopping the N 2  purge of the other gas supply lines. That is, in order to eliminate the influence of the other gas supply lines, the Cv value is calculated by flowing the N 2  gas only to the first gas supply line. By performing the N 2  purge for 30 minutes or longer, it is possible to stabilize the temperature of a diaphragm as sheet material inside the valve  52 . Then, by stabilizing the temperature of the diaphragm, it is possible to avoid the fluctuation of the Cv value due to expansion/contraction of the diaphragm sensitive to the temperature. At this time, the open/close state of the valve  67  by the controller  41  is fully open. 
     After the above-described N 2  purge is performed for 30 minutes or longer, a calculation process is performed by an incorporated program to calculate a Cv value from a pressure value of the pressure gauge  80 . The calculated Cv value is formed to be able to be notified to a worker. Then, the controller  41  compares the calculated Cv value with a reference value or range to determine whether or not it is appropriate. 
     In the present embodiments, in the fifth step, an appropriate range of Cv value that does not significantly affect the film thickness of a product is set in advance, and this Cv value is stored in the storage device  41   c . If a measured Cv value deviates from the appropriate range, a warning message indicating that the Cv value deviated from the appropriate range can be displayed on the screen of a liquid crystal display device of the input/output device  411 . In addition, if the measured Cv value deviates from the appropriate range, it may be possible to notify the worker of the fact by a notification means such as a warning lamp or a warning sound. In the long-term operation, for example, since the valve Cv value has shifted, notification can be made to urge replacement of the target part (valve). Moreover, since it is possible to change the Cv value by valve temperature, notification can be made to urge valve temperature adjustment. 
     The flow rate of the N 2  gas in the fifth step and the flow rate of the N 2  gas in the fourth step are set to be the same. Specifically, for example, in full scale 10 slm of MFC, in consideration of flow rate control stability, setting to 9 slm corresponding to 90% thereof is included. Moreover, it is preferable to set not only the N 2  gas flow rate but also the pressure, temperature, and the like under the same condition. As a result, in the fourth step (purge step), there is no need to set a special processing condition, and the fifth step can be started immediately after the fourth step only by closing the valves installed in the other gas supply lines, thereby shortening step processing time. 
     Furthermore, when the pressure, temperature, flow rate, processing time, etc. in this fifth step are set to be the same as those in the processing step of the process recipe, the Cv value of the valve  52  can be calculated under the process condition close to the process recipe, which is preferable since the reliability of the calculated Cv value can be improved. Thus, in the fifth step, the Cv value can be calculated in a state where the internal pressure of the process chamber  2  is reduced to match the process condition of the process recipe. 
     In particular, the present embodiments include the step of heating the N 2  gas via a valve heater which is a heating member installed in the valve  52 . Thus, by using the valve heater, the N 2  gas can be kept constant at a certain set temperature, so that the influence of the temperature on the inert gas can be suppressed. Therefore, temperature control of the diaphragm in the valve  52  can be performed simply and appropriately. 
     Since the condition for measuring the Cv value is fixed in advance, the condition of the step of calculating the Cv value in at least the fifth step is fixed. For example, a N 2  gas as gas species, a N 2  gas flow rate, pressure, temperature, and the like are preset. In addition, when the Cv value is measured, for example, if a valve which is the target part is heated, it is necessary to heat the other valves similarly. 
     Next, as a sixth step, the internal pressure of the process chamber  2  is returned to the atmospheric pressure. 
     The third step, the fourth step, and the sixth step are steps required to evacuate the process chamber  2 . 
     Next, as a seventh step, as the boat-unloading step of the process recipe, the lower part of the process chamber  2  is opened and the boat  32  is unloaded from the process chamber  2 . 
     Next, as an eighth step, the process chamber  2  is returned to the normal standby state. This is the end of the process of processing the correction recipe. 
     As described above, the process of executing the correction recipe includes a step of supplying a predetermined amount of N 2  gas to a gas supply line provided with the valve  52 , with the valve  67  for adjusting the internal pressure of the process furnace  29  fully opened, a step of detecting a pressure value of the gas supply line while supplying the N 2  gas, and a step of calculating a Cv value based on the detected pressure value. 
     According to the present embodiments, if the calculated Cv value is out of the appropriate range, the worker can immediately check whether or not there is an abnormality in the settings of temperature, flow rate, processing time, and the like in the processing process. When there is no abnormality in each setting condition, the worker can consider repair, replacement, or the like of the valve which is the target part for which the Cv value is measured. As a result, it is possible to prevent the occurrence of Cv value deviation due to long-term operation and external factors and hence the occurrence of product lot-out due to film thickness fluctuation. 
     By executing the process of the correction recipe for checking the Cv value of the valve  52  as shown in  FIG.  5    for each batch, it is possible to check the fluctuation of the Cv value of the valve  52 . Although the correction recipe may be carried out each time the process recipe is executed once, there is also a trade-off with productivity, so it is not limited to such frequency. For example, the correction recipe may be carried out each time the process recipe is executed a predetermined number of times (one or more times) to know the fluctuation of the Cv value of the valve  52  accompanying the execution of the process recipe. In addition, it is also possible to operate the correction recipe every predetermined cycle, such as once a week or once a month, thereby knowing the fluctuation of the Cv value of the valve  52  at a predetermined cycle. 
     The correction recipe in the present embodiments is executed, for example, after maintenance such as replacement of each element, member, etc. of the process furnace  29  as shown in  FIG.  3   . In particular, by executing the correction recipe after the replacement of the valve  52  which is the target parts for which the Cv value is to be measured, it is possible to know the fluctuation of the Cv value of the valve  52  accompanying the parts replacement. 
     From such a point of view, the present embodiments are also a method of managing parts since the Cv value of the target parts is managed. When the valve  52 , which is a supply valve, is replaced with a new one, by executing the correction recipe after replacing the valve  52 , the Cv value of the new valve  52  can be known before the new valve  52  is used. 
     It is also possible to execute the correction recipe after the maintenance work of the valve heater which is the heating member. Thereby, the fluctuation of the Cv value of the valve  52  can be known corresponding to the valve heater after the maintenance work. 
     Furthermore, in the present embodiments, the process condition of the process recipe can be changed, and the correction recipe can be executed after the process condition of the process recipe is changed. Thereby, the fluctuation of the Cv value of the valve  52  can be known corresponding to the process recipe before and after the change of the process condition. 
     In addition, the correction recipe is executed, for example, to be incorporated into a maintenance recipe for the process furnace  29 . This maintenance recipe is a recipe for performing maintenance work such as inspection, stabilization of operation, and initialization for the whole or each element of the process furnace  29 , and also includes a recipe (purge recipe) for purging the process furnace  29 . The clear difference between the correction recipe and the purge recipe is that step 5 in the correction recipe is not in the purge recipe. Therefore, when incorporating the correction recipe into the purge recipe, it is only necessary to add this step 5. By incorporating the correction recipe into the maintenance recipe (including the purge recipe), it is not necessary to create a new recipe especially as the correction recipe, and the correction recipe can be executed utilizing the existing recipe. 
     The purge recipe is executed, for example, as a particle countermeasure for the process furnace  29 . As one example, the purge recipe is performed after executing the process recipe a predetermined number of times or after maintenance. When the correction recipe, which is a recipe for checking the Cv value of the valve  52 , is incorporated into this purge recipe, the correction recipe can be simultaneously executed at the timing of executing the purge recipe. Since the Cv value of the valve  52  can be checked by the correction recipe each time the purge recipe is executed, for example, it is possible to suppress the deviation of the Cv value due to the change with time. In this manner, the correction recipe is executed before the Cv value deviation (for example, the substrate film thickness abnormality) occurs rather than after the Cv value deviation occurs. 
     The bar graph of  FIG.  6    is an example of the check result of a Cv value by an experiment at a temperature measurement position as shown in  FIG.  7   . 
       FIG.  7    is a view showing that a heating area of a valve heater is indicated by a two-dot chain line, and for the same valve  52 , a temperature measurement position TD by a temperature sensor of the valve heater is different between  FIG.  7 A  and  FIG.  7 B . That is,  FIG.  7 A  shows that the temperature measurement position TD by the temperature sensor of the valve heater is a position away from the valve  52 , and  FIG.  7 B  shows that the temperature of the valve  52  is directly measured. In  FIG.  7 B  showing that the temperature of the valve  52  is directly measured, the Cv value is checked for two temperatures of the valve  52 , 100° C. and 120° C. In  FIG.  7 A , the temperature of the valve is fixed at 120° C. The bar graph of  FIG.  6 A  corresponds to  FIG.  7 A , and the two bar graphs of  FIG.  6 B  respectively correspond to the two temperatures of the valve  52  in  FIG.  7 B . 
     From  FIGS.  6 A and  6 B , it can be seen that there is a difference in Cv value by changing the temperature measurement position of the valve heater. Further, it can be understood from the comparison between the two bar graphs in  FIG.  6 B  that there is a difference in Cv value even when the temperature setting of the valve heater is changed. That is, it can be seen that there is a difference in Cv values due to such a slight condition difference. 
       FIG.  8    is a graph of film thickness data in the temperature setting shown in  FIG.  7 A  and the two temperature settings shown  FIG.  7 B . The horizontal axis in  FIG.  8    represents an average value of film thickness values (unit: angstrom) measured at a plurality of predetermined locations in the plane of the wafer  31  processed under the conditions shown in  FIGS.  7 A and  7 B . The vertical axis in  FIG.  8    represents a monitor position in the transfer direction (vertical direction) of a predetermined number of wafers  31  held on the boat  32 , in which “180” of a boat slot indicates a position of the upper end of a substrate-holding area that holds the wafers  31  of the boat  32  and “0” of the boat slot indicates a position of the lower end of the same substrate-holding area. 
     The lowest Cv value in  FIGS.  6 A and  6 B  is a case of valve heater B at 120° C. In this case, it can be seen from  FIG.  8    that the film thickness is the smallest at any monitor position. The highest Cv value in  FIGS.  6 A and  6 B  is a case of valve heater B at 100° C. In this case, it can be seen from  FIG.  8    that the film thickness is the largest at any monitor position. In this way, a minute Cv value difference as shown in  FIG.  6    affects the film thickness. That is, even a slight condition difference causes a fluctuation of Cv value, and this fluctuation of Cv value affects the film thickness. Therefore, as the present embodiments, it can be understood that checking of the Cv value by the correction recipe is important and effective. 
     As the present embodiments, since the Cv value can be checked by executing the correction recipe each time the process recipe is executed a predetermined number of times (one or more times), the fluctuation of film thickness due to the deviation of the Cv value can be predicted in advance, thereby preventing product lot-out due to the fluctuation of Cv value. 
     Further, according to the present embodiments, it is possible to prevent product lot-out due to deviation of Cv value by long-term operation or external factors. 
     Other Embodiments of the Present Disclosure 
     Although the embodiments of the present disclosure have been concretely described above, the present disclosure is not limited to the above-described embodiments but various modifications can be made without departing from the spirit and scope of the present disclosure. 
     In the above-described embodiments, a gas source for N 2  purge in the correction recipe shown in  FIG.  5    is the carrier gas source  72 . However, this N 2  purge gas source may be the carrier gas source  74  or may be separately provided. In addition, the empty boat  32  is used in the correction recipe shown in  FIG.  5   . However, a dummy substrate may be loaded into the boat slot of the boat as the case of processing the product substrate. In addition, the heating member (heater) is provided in the valve  52  and the reservoir  51 . However, the heating member (heater) may be provided in the entire first gas supply line or may be provided in at least the valve  52 , the reservoir  51 , and the first gas supply pipe  47  downstream of the reservoir  51 . Further, in the above-described embodiments, the target part is the valve  52 , but the present disclosure is not limited thereto. The target parts may be any valve provided in the first gas supply line and may be any valve for supply/stop of a gas contributing to a process by an opening/closing operation. 
     Furthermore, when the calculated Cv value is out of the appropriate range, the temperature setting of the valve may be changed so that the Cv value is within the appropriate range, and the above-mentioned fifth step may be repeatedly executed. 
     For example, as a film-forming process performed by the substrate processing apparatus, a case where the DCS gas is used as a source (liquid source), the NH 3  gas is used as a reactant (reaction gas), and a SiN film is formed over the wafer by alternately supplying these gases has been illustrated in the above-described embodiments. However, the present disclosure is not limited thereto. That is, any liquid precursor may be used as the source and any gas that reacts with the source to perform film processing may be used as the reactant to form other types of thin films. Furthermore, even when three or more types of process gases are used, the present disclosure can be applied as long as a film-forming process is performed by alternately supplying these gases. 
     Further, for example, it has been illustrated in the above-described embodiments that a process performed by the substrate processing apparatus is the film-forming process in a semiconductor device. However, the present disclosure is not limited thereto. That is, the process may be a process of forming an oxide film or a nitride film or a process of forming a film containing metal, other than the film-forming process. Further, the specific contents of the substrate processing are unquestioned and can be suitably applied not only to the film-forming process but also to other substrate processing such as annealing, oxidizing, nitriding, diffusion, lithography, and so on. 
     Furthermore, the present disclosure can be suitably applied to other substrate processing apparatuses such as an annealing apparatus, an oxidizing apparatus, a nitriding apparatus, an exposure apparatus, a coating apparatus, a drying apparatus, a heating apparatus, a processing apparatus using plasma, etc., or combinations thereof. Further, in the present disclosure, these devices may be mixed. 
     In addition, for example, a semiconductor-manufacturing process has been illustrated in the above-described embodiments. However, the present disclosure is not limited thereto. For example, the embodiments may be used for a liquid precursor tank and an intermediate storage tank for storing a liquid requiring high cleanliness of liquid in the chemical industry field, a liquid tank incorporated in a vaporizer, etc. The liquid in the chemical industry referred to here is, for example, pure water, hydrogen peroxide water, ammonia water, alcohols, organic acids, etc. 
     Further, part of the configuration of some embodiments can be replaced with the configuration of other embodiments, and the configuration of some embodiments can be added to the configuration of other embodiments. Moreover, it is also possible to add, delete, and replace other configurations for part of the configurations of the respective embodiments. 
     Further, an example of using a N 2  gas as the inert gas has been illustrated in the above embodiments. However, the present disclosure is not limited thereto. For example, the inert gas may be a rare gas such as an Ar gas, a He gas, a Ne gas, a Xe gas, etc., in which case a rare gas source is required. Furthermore, it is necessary to connect this rare gas source to the first gas supply pipe  47  so that the rare gas can be introduced from the valve  81 . 
     According to the present disclosure in some embodiments, it is possible to prevent the occurrence of product lot-out due to fluctuation of the characteristic value of a valve by long-term operation or external factors. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.