Patent Publication Number: US-9899211-B2

Title: Method of manufacturing semiconductor device, substrate processing apparatus and non-transitory computer-readable recording medium

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 13/788,122, filed Mar. 7, 2013, which claims priority from Japanese Patent Application No. 2012-05378, filed on Mar. 9, 2012, the entire content of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a method of manufacturing a semiconductor device, including a process of forming a film on a substrate, a method of processing a substrate, a substrate processing apparatus, and a non-transitory computer-readable recording medium for storing instructions for executing such methods. 
     BACKGROUND 
     When a film, such as an insulating film to form a sidewall spacer (SWS) of a gate electrode in a transistor, is formed on a substrate of a semiconductor device, there is a need to form the film at a low temperature in order to prevent diffusion of impurities. There is also a need for such an insulating film to have a low dielectric constant in order to provide a small parasitic capacitance and have a high hydrogen fluoride (HF) resistance in order to maintain its shape in a cleaning process after forming the sidewall spacer. A high quality insulating film to meet such a need may be provided by controlling a composition ratio of the film, for example, a percentage of silicon (Si), oxygen (O), carbon (C), nitrogen (N) or the like contained in the film. Moreover, there is an additional need to control conditions for supplying various kinds of process gases for the purpose of controlling the film composition ratio. 
     A plurality of process gases have been used to form a film such as the above-mentioned sidewall spacer film in order to further reduce a dielectric constant in a low temperature region and improve the HF resistance. However, if for example an amount of gas exceeding an exhaust capacity is exhausted at one time, gas may stay in an exhaust pipe (exhaust line), which may result in deposition of byproducts in the exhaust pipe and increase in a back pressure of a vacuum pump disposed in the exhaust pipe, and hence cause blocking of the exhaust pipe. 
     SUMMARY 
     The present disclosure provides some embodiments of a semiconductor device manufacturing method, a substrate processing method, a substrate processing apparatus and a computer-readable recording medium for storing instructions thereon for executing such methods, which are capable of preventing byproducts from being deposited in an exhaust pipe when a film is formed. 
     According to some embodiments, there is provided a method of manufacturing a semiconductor device, including: forming a film on a substrate by performing a cycle a predetermined number of times, the cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying an amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped. A degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     According to some other embodiments, there is provided is a method of processing a substrate, including: forming a film on the substrate by performing a cycle a predetermined number of times, the cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying an amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped. A degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     According to some other embodiments, there is provided a substrate processing apparatus including: a process chamber configured to accommodate a substrate; a raw material gas supply system configured to supply a raw material gas to the substrate in the process chamber; an amine-based gas supply system configured to supply an amine-based gas to the substrate in the process chamber; an exhaust line configured to exhaust the interior of the process chamber; an exhaust valve disposed in the exhaust line; and a controller configured to control the raw material gas supply system, the amine-based gas supply system, the exhaust line and the exhaust valve such that a film is formed on the substrate by performing a cycle a predetermined number of times, the cycle including: supplying the raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying the amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped. A degree of valve opening of the exhaust valve is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     According to yet other embodiments, there is provided a computer-readable recording medium storing a program that causes a computer to perform a method of manufacturing a semiconductor device, the method including: forming a film on a substrate by performing a cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying an amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped. A degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a configuration of a vertical treatment furnace of a substrate processing apparatus, in which a portion of the treatment furnace is shown by a longitudinal sectional view, according to some embodiments. 
         FIG. 2  is a schematic view illustrating a configuration of the vertical treatment furnace of the substrate processing apparatus, in which a portion of the treatment furnace is shown by a sectional view taken along line A-A in  FIG. 1 . 
         FIG. 3  is a schematic view illustrating a configuration of a controller of the substrate processing apparatus, according to some embodiments. 
         FIG. 4  is a flow chart illustrating a flow of film formation according to a first embodiment. 
         FIG. 5  is a timing diagram of gas being supplied in a film forming sequence of the first embodiment. 
         FIG. 6  is a flow chart illustrating a flow of film formation according to a second embodiment. 
         FIG. 7  is a timing diagram of gas being supplied in a film forming sequence of the second embodiment. 
         FIGS. 8A and 8B  are a timing diagram of gas being supplied in a film forming sequence of an example of the present disclosure and a timing diagram of gas being supplied in a film forming sequence of a comparative example, respectively. 
     
    
    
     DETAILED DESCRIPTION 
     A back pressure of a vacuum pump disposed in an exhaust line may be increased when a film is formed on a substrate by performing a cycle a predetermined number of times, the cycle including supplying a raw material gas to the substrate in a process chamber, exhausting the raw material gas remaining in the process chamber through the exhaust line in a state where the supply of the raw material gas is being stopped, supplying an amine-based gas to the substrate in the process chamber, and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped. Specifically, it has been confirmed that a considerable amount of reaction byproducts was adhered to a downstream side of the vacuum pump in the exhaust line, in particular in a portion between a trap device and a harm-removing device in the downstream side of the vacuum pump in the exhaust line and acted as the cause of increase in the back pressure of the vacuum pump. 
     In addition, the reaction byproducts may be produced by a reaction of the raw material gas remaining in the downstream side of the vacuum pump in the exhaust line, in particular in the portion between the trap device and the harm-removing device, with a large amount of the amine-based gas exhausted at one time in the process of exhausting the amine-based gas remaining in the process chamber. That is, it has been found that, although the process of exhausting the raw material gas remaining in the process chamber was performed after the process of supplying the raw material gas, as the raw material gas stayed in the downstream side of the vacuum pump of the exhaust line and a large amount of the amine-based gas was exhausted at one time in the process of exhausting the amine-based gas remaining in the process chamber after the process of supplying the amine-based gas, a large amount of reaction byproducts may be produced by the reaction of the stayed raw material gas with the large amount of the amine-based gas exhausted at one time. It also has been found that, with an increase in the amount of the amine-based gas exhaust per unit time, there was a tendency to raise a probability of reaction of the stayed raw material gas with the amine-based gas and an increase an amount of adhered reaction byproducts. 
     This effect is noticeable when a gas containing a halogen element, particularly a chlorine element was used for the raw material gas and an amine was used for the amine-based gas. It also has been found that, with an increase in the amount of amine-based gas exhaust per unit time, a probability of reaction of the stayed raw material gas with the amine-based gas was raised and an amount of produced reaction byproducts was increased, which is likely to block the exhaust line. It also has been found that the reaction byproducts contained an amine halide such as amine chloride or the like. It also has been confirmed that the effect of increase in the back pressure of the vacuum pump disappeared when the amine-based gas was replaced with NH 3  gas or O 2  gas which has a higher vapor pressure than the amine-based gas. In other words, the technical purpose of the present disclosure is to overcome the problems which occurred when the amine-based gas having a relatively low vapor pressure (i.e., having a lower vapor pressure than at least NH 3  gas and O 2  gas) was used. 
     Various embodiments will be now described with reference to the drawings. 
     &lt;First Embodiment&gt; 
     (1) Configuration of Substrate Processing Apparatus 
       FIG. 1  is a schematic view illustrating a configuration of a vertical treatment furnace  202  of a substrate processing apparatus, according to some embodiments, in which a portion of the treatment furnace is shown by a longitudinal sectional view.  FIG. 2  is a schematic view illustrating a configuration of the vertical treatment furnace  202  of the substrate processing apparatus, according to some embodiments, in which a portion of the treatment furnace is shown by a sectional view taken along line A-A in  FIG. 1 . 
     As shown in  FIG. 1 , the vertical treatment furnace  202  has a heater  207  as a heating member (heating mechanism). The heater  207  has a cylindrical shape and is supported by a heater base (not shown) as a support plate so as to be vertically arranged. The heater  207  acts as an activation mechanism to activate a gas with heat, as will be described later. 
     A reaction tube  203  forming a reaction vessel (process vessel) is disposed inside the heater  207  in a concentric form along the heater  207 . The reaction tube  203  is made of a heat resistant material such as, for example, quartz (SiO 2 ), silicon carbide (SiC) or the like and has a cylindrical shape with its upper end closed and its lower end opened. A process chamber  201  is formed in a hollow of the reaction tube  203  and is configured to accommodate wafers  200 . The wafers  200  are horizontally stacked in multiple stages to be aligned in a vertical direction in a boat  217  which will be described later. 
     A first nozzle  249   a , a second nozzle  249   b  and a third nozzle  249   c  are disposed to penetrate through a lower side of the reaction tube  203 . The first nozzle  249   a , the second nozzle  249   b  and the third nozzle  249   c  are respectively connected to a first gas supply pipe  232   a , a second gas supply pipe  232   b  and a third gas supply pipe  232   c . Additionally, a fourth gas supply pipe  232   d  is connected to the third gas supply pipe  232   c . In this way, the three nozzles  249   a ,  249   b  and  249   c  and the four gas supply pipes  232   a ,  232   b ,  232   c  and  232   d  are provided in the reaction tube  203  to allow several kinds of (4 in this example) gases to be supplied into the process chamber  201 . 
     An exhaust pipe  231  is disposed at a lower portion of the reaction tube  203 . In addition, a metal manifold (not shown) to support the reaction tube  203  may be disposed below the reaction tube  203  and the nozzles  249   a ,  249   b  and  249   c  may be disposed to penetrate through a side wall of the metal manifold. In this case, the exhaust pipe  231  may be disposed at the metal manifold, rather than the lower portion of the reaction tube  203 . 
     A mass flow controller (MFC)  241   a  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   a  are disposed in the first gas supply pipe  232   a  in this order from the upstream direction. In addition, a first inert gas supply pipe  232   e  is connected to the downstream side of the valve  243   a  of the first gas supply pipe  232   a . A mass flow controller (MFC)  241   e  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   e  are disposed in the first inert gas supply pipe  232   e  in this order from the upstream direction. In addition, the above-mentioned first nozzle  249   a  is connected to a leading end of the first gas supply pipe  232   a . The first nozzle  249   a  is vertically disposed along an inner wall of the reaction tube  203  in a circular arc-shaped space between the inner wall of the reaction tube  203  and the wafers  200 . The first nozzle  249   a  is disposed in a flank of a wafer arrangement region where the wafers  200  are arranged. The first nozzle  249   a  is configured as an L-like long nozzle and has its horizontal portion disposed to penetrate through the lower side wall of the reaction tube  203  and its vertical portion disposed to rise from at least one end of the wafer arrangement region toward the other end thereof. A plurality of gas supply holes  250   a  through which gas is supplied is disposed at a side surface of the first nozzle  249   a . The gas supply holes  250   a  are opened toward a center of the reaction tube  203 . The gas supply holes  250   a  are disposed to span from the bottom to top of the reaction tube  203  at a predetermined opening pitch. Each of the gas supply holes  250   a  has the same opening area. A first gas supply system is mainly constituted by the first gas supply pipe  232   a , the mass flow controller  241   a , the valve  243   a  and the first nozzle  249   a . In addition, a first inert gas supply system is mainly constituted by the first inert gas supply pipe  232   e , the mass flow controller  241   e  and the valve  243   e.    
     A mass flow controller (MFC)  241   b  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   b  are disposed in the second gas supply pipe  232   b  in this order from the upstream direction. In addition, a second inert gas supply pipe  232   f  is connected to the downstream side of the valve  243   b  of the second gas supply pipe  232   b . A mass flow controller (MFC)  241   f  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   f  are disposed in the second inert gas supply pipe  232   f  in this order from the upstream direction. In addition, the above-mentioned second nozzle  249   b  is connected to a leading end of the second gas supply pipe  232   b . The second nozzle  249   b  is vertically disposed along the inner wall of the reaction tube  203  in the circular arc-shaped space between the inner wall of the reaction tube  203  and the wafers  200 . The second nozzle  249   b  is disposed in the flank of the wafer arrangement region where the wafers  200  are arranged. The second nozzle  249   b  is configured as an L-like long nozzle and has its horizontal portion disposed to penetrate through the lower side wall of the reaction tube  203  and its vertical portion disposed to rise from at least one end of the wafer arrangement region toward the other end thereof. A plurality of gas supply holes  250   b  through which gas is supplied is disposed at a side surface of the second nozzle  249   b . The gas supply holes  250   b  are opened toward the center of the reaction tube  203 . The gas supply holes  250   b  are disposed to span from the bottom to top of the reaction tube  203  at a predetermined opening pitch. Each of the gas supply holes  250   b  has the same opening area. A second gas supply system is mainly constituted by the second gas supply pipe  232   b , the mass flow controller  241   b , the valve  243   b  and the second nozzle  249   b . In addition, a second inert gas supply system is mainly constituted by the second inert gas supply pipe  232   f , the mass flow controller  241   f  and the valve  243   f.    
     A mass flow controller (MFC)  241   c  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   c  are disposed in the third gas supply pipe  232   c  in this order from the upstream direction. In addition, a fourth gas supply pipe  232   d  is connected to the downstream side of the valve  243   c  of the third gas supply pipe  232   c . A mass flow controller  241   d  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   d  are disposed in the fourth gas supply pipe  232   d  in this order from the upstream direction. In addition, a third inert gas supply pipe  232   g  is connected to the downstream side of a connection position of the third gas supply pipe  232   c  to the fourth gas supply pipe  232   d . A mass flow controller  241   g  as a flow rate controller (a flow rate control unit) and an opening/closing valve  243   g  are disposed in the third inert gas supply pipe  232   g  in this order from the upstream direction. In addition, the above-mentioned third nozzle  249   c  is connected to a leading end of the third gas supply pipe  232   c . The third nozzle  249   c  is vertically disposed along the inner wall of the reaction tube  203  in the circular arc-shaped space between the inner wall of the reaction tube  203  and the wafers  200 . The third nozzle  249   c  is disposed in the flank of the wafer arrangement region where the wafers  200  are arranged. The third nozzle  249   c  is configured as an L-like long nozzle and has its horizontal portion disposed to penetrate through the lower side wall of the reaction tube  203  and its vertical portion disposed to rise from at least one end of the wafer arrangement region toward the other end thereof. A plurality of gas supply holes  250   c  through which gas is supplied is disposed in a side surface of the third nozzle  249   c . The gas supply holes  250   c  are opened toward the center of the reaction tube  203 . The gas supply holes  250   c  are disposed to span from the bottom to top of the reaction tube  203  at a predetermined opening pitch. Each of the gas supply holes  250   c  has the same opening area. A third gas supply system is mainly constituted by the third gas supply pipe  232   c , the mass flow controller  241   c , the valve  243   c  and the third nozzle  249   c . In addition, a fourth gas supply system is mainly constituted by the fourth gas supply pipe  232   d , the mass flow controller  241   d , the valve  243   d  and the third nozzle  249   c . In addition, a third inert gas supply system is mainly constituted by the third inert gas supply pipe  232   g , the mass flow controller  241   g  and the valve  243   g.    
     In the gas supply systems, gas is transferred via the nozzles  249   a ,  249   b  and  249   c  arranged in the circular arc-shaped longitudinal space defined by the inner wall of the reaction tube  203  and ends of the plurality of loaded wafers  200 , and supplied into the reaction tube  203  near the wafers  200  from the gas supply holes  250   a ,  250   b  and  250   c  opened in the nozzles  249   a ,  249   b  and  249   c , respectively. The gas supplied into the reaction tube  203  mainly flows in a horizontal direction, that is, a direction in parallel to the surface of the wafers  200  in the reaction tube  203 . This configuration provides an advantage of uniformly supplying the gas to the wafers  200  and forming a uniform thickness of a film on the wafers  200 . Although a residual gas after the reaction flows toward the exhaust mechanism, that is, the exhaust pipe  231 , a direction of flow of the residual gas is specified by a position of the exhaust mechanism without being limited to the vertical direction. 
     A raw material gas containing a halogen element and another element, for example, a chlorosilane-based raw material gas containing at least a silicon (Si) element and a chlorine (Cl) element, is supplied from the first gas supply pipe  232   a  into the process chamber  201  via the mass flow controller  241   a , the valve  243   a  and the first nozzle  249   a . As used herein, the chlorosilane-based raw material gas refers to silane-based gas containing a chloro group as a halogen group. In this example, hexachlorodisilane (Si 2 Cl 6 , or HCDS) gas may be used as the chlorosilane-based raw material gas. Since the HCDS is in a liquid state at room temperature and atmospheric pressure, the liquefied HCDS may be supplied as HCDS gas after being vaporized by a vaporizing system (not shown) such as a vaporizer or a bubbler. 
     A reaction gas (first reaction gas), for example, an amine-based gas containing a carbon (C) element and a nitrogen (N) element, is supplied from the second gas supply pipe  232   b  into the process chamber  201  via the mass flow controller  241   b , the valve  243   b  and the second nozzle  249   b . The amine-based gas may include amines such as ethyl amine, methyl amine, propyl amine, isopropyl amine, butyl amine and so on. As used herein, amine is a generic term of compounds having a hydrocarbon group such as an alkyl group or the like, substituting a hydrogen atom of ammonia (NH 3 ). That is, amines contain a hydrocarbon group such as an alkyl group or the like. As used herein, the amine-based gas refers to a gas having an amine group, such as a gas with an evaporated amine, and is only composed of three elements, a carbon (C) element, a nitrogen (N) element and a hydrogen (H) element constituting an amine group. That is, the amine-based gas is a gas which does not contain a silicon element and a metal element. In this example, a triethylamine ((C 2 H 5 ) 3 N, TEA) gas may be used as the amine-based raw material gas. Since the TEA is in a liquid state at room temperature and atmospheric pressure, the liquefied TEA may be supplied as a TEA gas after being vaporized by a vaporizing system (not shown) such as a vaporizer or a bubbler. 
     Another reaction gas (second reaction gas), for example, a gas containing oxygen (O) (oxygen-containing gas), is supplied from the third gas supply pipe  232   c  into the process chamber  201  via the mass flow controller  241   c , the valve  243   c  and the third nozzle  249   c . In this example, an oxygen (O 2 ) gas may be used as the oxygen-containing gas. 
     Another reaction gas (second reaction gas), for example, a gas containing nitrogen (N) (nitrogen-containing gas), is supplied from the fourth gas supply pipe  232   d  into the process chamber  201  via the mass flow controller  241   d , the valve  243   d , the third gas supply pipe  232   c  and the third nozzle  249   c . In this example, an ammonia (NH 3 ) gas may be used as the nitrogen-containing gas. 
     A nitrogen (N 2 ) gas is supplied from the inert gas supply pipes  232   e ,  232   f  and  232   g  into the process chamber  201  via the mass flow controllers  241   e ,  241   f  and  241   g , the valves  243   e ,  243   f  and  243   g , the gas supply pipes  232   a ,  232   b , and  232   c  and the nozzles  249   a ,  249   b  and  249   c , respectively. 
     For example, when the gases are flown from the gas supply pipes as described above, a raw material gas supply system, i.e., a chlorosilane-based raw material gas supply system, is constituted by the first gas supply system, a reaction gas supply system (first reaction gas supply system), i.e., an amine-based gas supply system, is constituted by the second gas supply system, a reaction gas supply system (second reaction gas supply system), i.e., an oxygen-containing gas supply system, is constituted by the third gas supply system, and a reaction gas supply system (second reaction gas supply system), i.e., a nitrogen-containing gas supply system, is constituted by the fourth gas supply system. 
     The exhaust pipe  231  to exhaust the internal atmosphere of the process chamber  201  is disposed in the reaction tube  203 . As shown in  FIG. 2 , when viewed from a cross section (along line A-A in  FIG. 1 ), the exhaust pipe  231  is disposed in a position opposite to a position where the gas supply holes  250   a  of the first nozzle  249   a , the gas supply holes  250   b  of the second nozzle  249   b  and the gas supply holes  250   c  of the third nozzle  249   c  of the reaction tube  203  are disposed, that is, a position opposite to the gas supply holes  250   a ,  250   b  and  250   c  with the wafers  200  interposed therebetween. In addition, as shown in  FIG. 1 , when viewed from a longitudinal section, the exhaust pipe  231  is disposed below a position where the gas supply holes  250   a ,  250   b  and  250   c  are disposed. With this configuration, gas supplied from the gas supply holes  250   a ,  250   b  and  250   c  to the neighborhood of the wafers  200  in the process chamber  201  flows in a horizontal direction, that is, a direction in parallel to surfaces of the wafers  200 , flows downward, and then is exhausted out of the exhaust pipe  231 . The main flow of gas in the process chamber  201  becomes a flow in the horizontal direction, as described previously. 
     The exhaust pipe  231  is connected with a pressure sensor (pressure detecting part)  245  for detecting the internal pressure of the process chamber  201 , an APC (Auto Pressure Controller) valve  244  as an exhaust valve formed as a pressure regulator (pressure regulating part), a vacuum pump  246  as a vacuum exhaust device, a trap device  247  for trapping reaction by-products, unreacted raw material gas and so on in exhaust gases, and a harm-removing device  248  for removing corrosive ingredients, toxic ingredients and so on contained in the exhaust gases. An exhaust system, i.e., an exhaust line, is mainly constituted through the exhaust pipe  231 , the APC valve  244  and the pressure sensor  245 . The vacuum pump  246 , the trap device  247  and the harm-removing device  248  may be also considered to be included in the exhaust system. 
     The APC valve  244  is a valve configured to perform/stop vacuum exhaust in the process chamber  201  by opening/closing the valve with the vacuum pump  246  actuated and adjust the internal pressure of the process chamber  201  by regulating a degree of valve opening with the vacuum pump  246  actuated. In other words, the exhaust system is configured to approach the “actual internal pressure” of the process chamber  201  to a predetermined “set pressure” by regulating the degree of valve opening of the APC valve  244  based on pressure information detected by the pressure sensor  245  while actuating the vacuum pump  246 . For example, when there is no change in a flow rate of a gas supplied into the process chamber  201  or supply of the gas into the process chamber  201  is stopped, the actual internal pressure of the process chamber  201  may be adjusted by changing the set internal pressure of the process chamber  201  and changing the degree of valve opening the APC valve  244  according to the set internal pressure. As a result, exhaust capability of the exhaust line is changed and the actual internal pressure of the process chamber  201  slowly (gradually) approaches the set pressure. In this manner, the “set internal pressure” of the process chamber  201  can be considered to be equal to a “target pressure” at the time when control of the internal pressure of the process chamber  201  is carried out, and the “actual internal pressure” of the process chamber  201  follows the target pressure. The phrase “the set internal pressure of the process chamber  201  is changed” has substantially the same meaning as “the degree of valve opening of the APC valve  244  is changed to change the exhaust capability of the exhaust line”, and may be considered as a “command to change the degree of valve opening of the APC valve  244 ”. 
     A seal cap  219 , which functions as a furnace opening cover for air-tightly blocking the bottom opening of the reaction tube  203 , is disposed below the reaction tube  203 . The seal cap  219  is configured to contact the bottom of the reaction tube  203  from below in the vertical direction. The seal cap  219  is made of, for example, metal such as stainless steel or the like and has a disc shape. An O-ring  220  as a seal member contacting the bottom of the reaction tube  203  is disposed in the top side of the seal cap  219 . A rotation mechanism  267  to rotate the boat  217  as a substrate support, which will be described later, is disposed below the seal cap  219 . A shaft  255  of the rotation mechanism  267  is connected to the boat  217  through the seal cap  219 . The rotation mechanism  267  is configured to rotate the wafers  200  by rotating the boat  217 . The seal cap  219  is configured to be vertically elevated or lowered by a boat elevator  115  as an elevation mechanism vertically disposed outside the reaction tube  203 . The boat elevator  115  is configured to carry the boat  217  into or out of the process chamber  201  by elevating or lowering the seal cap  219 . That is, the boat elevator  115  is configured as a transfer device (transfer mechanism) to transfer the boat  217 , i.e., the wafers  200 , into or out of the process chamber  201 . 
     The boat  217 , which is utilized as the substrate support, is made of, for example, a heat resistant material such as quartz, silicon carbide or the like and is configured to support the wafers  200  horizontally stacked in multiple stages with the center of the wafers  200  concentrically aligned. In addition, a heat insulating member  218  made of, for example, a heat resistant material such as quartz, silicon carbide or the like, is disposed below the boat  217  and is configured to make it difficult for heat from the heater  207  to be transferred to the seal cap  219 . The heat insulating member  218  may be constituted by a plurality of heat insulating plates, each made of a heat resistant material such as quartz, silicon carbide or the like, and a heat insulating plate holder to support these heat insulating plates horizontally in multiple stages. 
     A temperature sensor  263  as a temperature detector is disposed within the reaction tube  203 . Based on temperature information detected by the temperature sensor  263 , a state of electric conduction to the heater  207  is adjusted such that the interior of the process chamber  201  has an intended temperature distribution. The temperature sensor  263  has an L-like shape, like the nozzles  249   a ,  249   b  and  249   c  and is disposed along the inner wall of the reaction tube  203 . 
       FIG. 3  is a schematic view illustrating a configuration of a controller of the substrate processing apparatus, according to some embodiments. As shown in  FIG. 3 , a controller  121  as a control unit (control means) is constituted by a computer including a CPU (Central Processing Unit)  121   a , a RAM (Random Access Memory)  121   b , a storage device  121   c  and an I/O port  121   d . The RAM  121   b , the storage device  121   c  and the I/O port  121   d  are configured to exchange data with the CPU  121   a  via an internal bus  121   e . An input/output device  122  constituted by, for example, a touch panel or the like is connected to the controller  121 . 
     The storage device  121   c  is constituted by, for example, a flash memory, a HDD (Hard Disk Drive) or the like. Control programs to control an operation of the substrate processing apparatus and process recipes describing substrate processing procedures and conditions, which will be described later, are readably stored in the storage device  121   c . The process recipes function as programs to cause the controller  121  to execute procedures in substrate processing which will be described later. Hereinafter, these process recipes and control programs are collectively simply referred to as programs. As used herein, the term “programs” may be intended to include process recipes only, control programs only, or both thereof. The RAM  121   b  is configured as a memory area (work area) in which programs and data read by the CPU  121   a  are temporarily stored. 
     The I/O port  121   d  is connected to the above-mentioned mass flow controllers  241   a ,  241   b ,  241   c ,  241   d ,  241   e ,  241   f  and  241   g , valves  243   a ,  243   b ,  243   c ,  243   d ,  243   e ,  243   f  and  243   g , pressure sensor  245 , APC valve  244 , vacuum pump  246 , heater  207 , temperature sensor  263 , rotation mechanism  267 , boat elevator  115  and so on. 
     The CPU  121   a  is configured to read and execute a control program from the storage device  121   c  and read a process recipe from the storage device  121   c  according to an operation command input from the input/output device  122 . The CPU  121   a  is further configured to control a flow rate adjustment operation of various gases by the mass flow controllers  241   a ,  241   b ,  241   c ,  241   d ,  241   e ,  241   f  and  241   g , an opening/closing operation of the valves  243   a ,  243   b ,  243   c ,  243   d ,  243   e ,  243   f  and  243   g , an opening/closing operation of the APC valve  244 , a pressure adjustment operation by the APC valve  244  based on the pressure sensor  245 , a temperature adjustment operation of the heater  207  based on the temperature sensor  263 , start and stop of the vacuum pump  246 , rotation and a rotation speed adjustment operation of the boat  217  by the rotation mechanism  267 , an elevation operation by the boat elevator  115 , etc., according to contents of the read process recipe. 
     The controller  121  may be configured as a general-purpose computer without being limited to a dedicated computer. For example, in the embodiment, the controller  121  may be configured by preparing an external storage device (for example, a magnetic tape, a magnetic disk such as a flexible disk or a hard disk, an optical disk such as CD or DVD, a magneto-optical disk such as MO, and a semiconductor memory such as a USB memory or a memory card)  123  which stores the above-described programs and installing the programs from the external storage device  123  into the general-purpose computer. A means for providing the programs for the computer is not limited to the case where the programs are provided through the external storage device  123 . For example, the programs may be provided using a communication means such as Internet, a dedicated line or the like, without the external storage device  123 . The storage device  121   c  and the external storage device  123  are implemented with a computer readable recording medium and will be hereinafter collectively simply referred to as a recording medium. The term “recording medium” may include the storage device  121   c  only, the external storage device  123  only, or both thereof. 
     (2) Substrate Processing Method 
     As one of processes of manufacturing a semiconductor device using the vertical treatment furnace  202  of the above-described substrate processing apparatus, an example of sequence of forming a film on the wafer  200  will be now described. In the following description, operations of various components constituting the substrate processing apparatus are controlled by the controller  121 . 
     In this embodiment, a film is formed on the wafer  200  by performing a cycle including a process of supplying a raw material gas for the wafer  200  in the process chamber  201 , exhausting the raw material gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the raw material gas is stopped , supplying an amine-based gas for the wafer  200  in the process chamber  201 , and exhausting the amine-based gas remaining in the process chamber  201  by means of the exhaust line, by a predetermined number of times. 
     More specifically, a film having a predetermined composition including predetermined elements and a predetermined thickness is formed on the wafer  200  by performing a cycle including a process of forming a predetermined element-containing layer on the wafer  200  by supplying a raw material gas to the heated wafer  200  in the process chamber  201 , exhausting the raw material gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the raw material gas is stopped , modifying the predetermined element-containing layer to form a first layer containing predetermined elements, nitrogen and carbon by supplying an amine-based gas to the heated wafer  200  in the process chamber  201 , exhausting the amine-based gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the amine-based gas is stopped, modifying the first layer to form a second layer by supplying a reaction gas different from the raw material gas and the amine-based gas to the heated wafer  200  in the process chamber  201 , and an exhausting the reaction gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the reaction gas is stopped, by a predetermined number of times (once or more). 
     In addition, under the state where the supply of the amine-based gas is stopped, the degree of valve opening of the APC valve  244  disposed in the exhaust line is changed in multiple stages in the act of exhausting the amine-based gas remaining in the process chamber  201 . More specifically, the act exhausting the amine-based gas remaining in the process chamber  201  includes a process of exhausting the amine-based gas remaining in the process chamber  201  with the degree of valve opening of the APC valve  244  as a first degree of valve opening and a process of exhausting the amine-based gas remaining in the process chamber  201  with the degree of valve opening of the APC valve  244  as a second degree of valve opening which is larger than the first degree of valve opening. 
     In other words, under the state where the supply of the amine-based gas is stopped, the exhaust capability through the exhaust line is changed in multiple stages in the act of exhausting the amine-based gas remaining in the process chamber  201 . More specifically, the act of exhausting the amine-based gas remaining in the process chamber  201  includes a process of exhausting the amine-based gas remaining in the process chamber  201  with the exhaust capability through the exhaust line as a first exhaust capability and a process of exhausting the amine-based gas remaining in the process chamber  201  with the exhaust capability through the exhaust line as a second exhaust capability which is larger than the first exhaust capability. 
     Alternatively, under the state where the supply of the amine-based gas is stopped, the set internal pressure of the process chamber  201  is changed in multiple stages in the act of exhausting the amine-based gas remaining in the process chamber  201 . More specifically, the act of exhausting the amine-based gas remaining in the process chamber  201  includes a process of exhausting the amine-based gas remaining in the process chamber  201  with the set internal pressure of the process chamber  201  as a first set internal pressure and a process of exhausting the amine-based gas remaining in the process chamber  201  with the set internal pressure of the process chamber  201  as a second set internal pressure which is larger than the first set internal pressure. 
     For example, plural kinds of gases containing plural elements constituting a film to be formed are simultaneously supplied in a conventional CVD (Chemical Vapor Deposition) method and plural kinds of gases containing plural elements constituting a film to be formed are alternately supplied in a conventional ALD (Atomic Layer Deposition) method. A SiO 2  film or a Si 3 N 4  film is formed by controlling supply conditions such as a flow rate of gas supply, gas supply time, process temperature and the like. In these techniques, the supply conditions are controlled such that a film stoichiometric composition ratio (O/Si) for the SiO 2  film is approximately equal to two and a film stoichiometric composition ratio (N/Si) for the Si 3 N 4  film approximately equal to 1.33. 
     In contrast, in this embodiment, the supply conditions are controlled such that a film to be formed has a stoichiometric composition ratio or a composition ratio different from the stoichiometric composition ratio. For example, the supply conditions are controlled such that at least one of plural elements constituting a film to be formed is supplied in excess of other elements in terms of a stoichiometric composition. An example of forming a film while controlling a film composition ratio which represents a ratio between plural elements constituting the film will be described below. 
     A film forming sequence according to this embodiment will be now described with reference to  FIGS. 4 and 5 .  FIG. 4  is a view illustrating a film forming flow according to this embodiment.  FIG. 5  is a view illustrating timings of gas supply in a film forming sequence according to this embodiment. An example of forming a silicon oxycarbonitride film (SiOCN film) or a silicon oxycarbide film (SiOC film), which is a silicon-based insulating film having a predetermined composition and a predetermined thickness, on the wafer  200  by performing a cycle including a process of forming a silicon-containing layer on the wafer  200  by supplying an HCDS gas as a raw material gas to the heated wafer  200  in the process chamber  201 , exhausting the HCDS gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the HCDS gas is stopped , modifying the silicon-containing layer to form a first layer containing silicon, nitrogen and carbon by supplying a TEA gas, which is an amine-based gas, to the heated wafer  200  in the process chamber  201 , exhausting the TEA gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the TEA gas is stopped, modifying the first layer to form a silicon oxycarbonitride film (SiOCN film) or a silicon oxycarbide film (SiOC film) as a second layer by supplying an O 2  gas, which is an oxygen-containing gas, as a reaction gas different from the raw material gas and the amine-based gas to the heated wafer  200  in the process chamber  201 , and exhausting the O 2  gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the O 2  gas is stopped, by a predetermined number of times (n times). 
     &lt;Wafer Charge and Boat Load&gt; 
     When a plurality of wafers  200  is loaded on the boat  217  (wafer charge), the boat  217  supporting the plurality of wafers  200  is lifted and loaded into the process chamber  201  by the boat elevator  115  (boat load). In this state, the seal cap  219  seals the bottom of the reaction tube  203  via the Oring  220 . 
     &lt;Pressure Adjustment and Temperature Adjustment&gt; 
     The interior of the process chamber  201  is vacuum-exhausted by the vacuum pump  246  to set the interior to a desired pressure (degree of vacuum). At this time, the internal pressure of the process chamber  201  is measured by the pressure sensor  245  and the APC valve  244  is feedback-controlled based on the measured pressure information (pressure adjustment). The vacuum pump  246  remains activated at least until the wafers  200  are completely processed. The interior of the process chamber  201  is heated by the heater  207  to set the interior to a desired temperature. At this time, a state of electric conduction to the heater  207  is feedback-controlled based on the temperature information detected by the temperature sensor  263  such that the interior of the process chamber  201  has a desired temperature distribution (temperature adjustment). The heating of the interior of the process chamber  201  by the heater  207  continues at least until the wafers  200  are completely processed. Subsequently, the boat  217  and the wafers  200  begin to be rotated by the rotation mechanism  267 . The rotation of the boat  217  and the wafers  200  by the rotation mechanism  267  continues at least until the wafers  200  are completely processed. 
     &lt;Process of forming silicon oxycarbonitride Film or silicon oxycarbide film&gt; 
     Thereafter, the following three steps (Steps 1 to 3) are sequentially performed. 
     &lt;Step 1&gt; 
     &lt;HCDS Gas Supply&gt; 
     The valve  243   a  of the first gas supply pipe  232   a  is opened to flow an HCDS gas into the first gas supply pipe  232   a . A flow rate of the HCDS gas flowing into the first gas supply pipe  232   a  is regulated by the mass flow controller  241   a . The HCDS gas with its flow rate regulated is supplied from the gas supply holes  250   a  of the first nozzle  249   a  into the process chamber  201  and is exhausted from the exhaust pipe  231 . At this time, the HCDS gas is supplied to the wafers  200 . At the same time, the valve  243   e  is opened to flow an inert gas such as an N 2  gas or the like into the first inert gas supply pipe  232   e . A flow rate of the N 2  gas flowing into the first inert gas supply pipe  232   e  is regulated by the mass flow controller  241   e . The N 2  gas with its flow rate regulated is supplied into the process chamber  201 , along with the HCDS gas, and is exhausted from the exhaust pipe  231 . At this time, in order to prevent the HCDS gas from being introduced into the second nozzle  249   b  and the third nozzle  249   c , the valves  243   f  and  243   g  are opened to flow the N 2  gas into the second inert gas supply pipe  232   f  and the third inert gas supply pipe  232   g . The N 2  gas is supplied into the process chamber  201  via the second gas supply pipe  232   b , the third gas supply pipe  232   c , the second nozzle  249   b  and the third nozzle  249   c  and is exhausted from the exhaust pipe  231 . 
     At this time, the APC valve  244  is appropriately regulated to set the internal pressure of the process chamber  201  to fall within a range of, for example, 1 to 13300 Pa, preferably 20 to 1330 Pa. The flow rate of the HCDS gas controlled by the mass flow controller  241   a  is set to fall within a range of, for example, 1 to 1000 sccm. The flow rates of the N 2  gases controlled by the mass flow controllers  241   e ,  241   f  and  241   g  are set to fall within a range of, for example, 100 to 10000 sccm. Time period during which the HCDS gas is supplied to the wafers  200 , that is, gas supply time (irradiation time), is set to fall within a range of, for example, 1 to 120 seconds, preferably 1 to 60 seconds. At this time, the heater  207  is set to a temperature such that the temperature of the wafers  200  is set to fall within a range of, for example, 250 to 700 degrees C., preferably 350 to 650 degrees C. If the temperature of the wafers  200  is less than 250 degrees C., it becomes difficult for HCDS to be chemisorbed onto the wafers  200 , which may result in difficulty in obtaining a practical film forming rate. This problem can be overcome by setting the temperature of the wafers  200  to 250 degrees C. or higher. If the temperature of the wafers  200  is set to 350 degrees C. or higher, HCDS can be more sufficiently adsorbed onto the wafers  200 , which may result in a higher film forming rate. If the temperature of the wafers  200  exceeds 700 degrees C., a CVD reaction is strengthened (i.e., a gas phase reaction becomes dominant), which may result in deteriorated uniformity of film thickness and difficulty in control thereof. When the temperature of the wafers  200  is 700 degrees C. or lower, it is possible to suppress such deterioration of the uniformity of film thickness and avoid difficulty in control thereof. In particular, when the temperature of the wafers  200  is 650 degrees C. or lower, a surface reaction becomes dominant, which facilitates secure of the uniformity of film thickness and control thereof. Thus, in some embodiments, the temperature of the wafers  200  will mainly fall within a range of 250 to 700 degrees C., preferably 350 to 650 degrees C. 
     The supply of the HCDS gas results in formation of a silicon-containing layer having a thickness of, for example, less than one atomic layer to several atomic layers on the wafers  200 . The silicon-containing layer may be a HCDS gas adsorption layer or a silicon layer or both thereof. In this example, the silicon-containing layer may be a layer which contains silicon (Si) and chlorine (Cl). In this example, the silicon layer is the generic term including a continuous layer made of silicon (Si), a discontinuous layer, or a silicon thin film composed of a combination of these continuous and discontinuous layers. The continuous layer made of Si is sometimes referred to as a silicon thin film. Si of which the silicon layer is made includes one which is not completely decoupled from Cl. The HCDS gas adsorption layer includes a HCDS gas molecule continuous chemical adsorption layer and a HCDS gas molecule discontinuous chemical adsorption layer. That is, the HCDS gas chemical adsorption layer includes a chemical adsorption layer having a thickness of one molecular layer or less constituted by HCDS molecules. The HCDS (Si 2 Cl 6 ) molecules constituting the HCDS gas chemical adsorption layer include those (Si x Cl y  molecules) in which Si is partially decoupled from Cl. That is, the HCDS chemical adsorption layer includes Si 2 Cl 6  molecule and/or Si x Cl y  continuous and discontinuous chemical adsorption layers. As used herein, the phrase “layer having a thickness of less than one atomic layer” means an atomic layer discontinuously formed and the phrase “layer having a thickness of one atomic layer” means an atomic layer continuously formed. Similarly, the phrase “layer having a thickness of less than one molecular layer” means a molecular layer discontinuously formed and the phrase “layer having a thickness of one molecular layer” means a molecular layer continuously formed. Under the condition where the HCDS gas is self-decomposed (pyrolyzed), that is, under the condition where a pyrolytic reaction of the HCDS gas occurred, Si is deposited on the wafers  200 , thereby forming the silicon layer. Under the condition where the HCDS gas is not self-decomposed (pyrolyzed), that is, under the condition where no pyrolytic reaction of the HCDS gas occurred, the HCDS gas is chemically adsorbed and deposited on the wafers  200 , thereby forming the HCDS gas chemical adsorption layer. Forming the silicon layer on the wafers  200  can advantageously provide a higher film formation rate than forming the HCDS gas adsorption layer on the wafers  200 . If the thickness of the silicon-containing layer formed on the wafers  200  exceeds several atomic layers, modification reaction in Steps 2 and 3, which will be described later, may not be applied to the entire silicon-containing layer. The minimum of thickness of the silicon-containing layer which can be formed on the wafers  200  is less than one atomic layer. Accordingly, the thickness of the silicon-containing layer may be set to fall within a range of less than one atomic layer to several atomic layers. When the thickness of the silicon-containing layer is not less than one atomic layer, i.e., one atomic layer or less, modification reaction in Steps 2 and 3, which will be described later, can be relatively expedited and time required for the modification reaction in Steps 2 and 3 can be shortened. Time required for the formation of the silicon-containing layer in Step 1 can be also shortened. As a result, processing time per cycle and hence total processing time can be shortened. In other words, a film formation rate can be increased. In addition, when the thickness of the silicon-containing layer is not less than one atomic layer, controllability for uniform film thickness can be improved. 
     &lt;Residual Gas Removal&gt; 
     After the silicon-containing layer is formed, the valve  243   a  of the first gas supply pipe  232   a  is closed to stop the supply of the HCDS gas. At this time, with the APC valve  244  of the exhaust pipe  231  opened, the interior of the process chamber  201  is vacuum-exhausted by the vacuum pump  246  and unreacted HCDS gas remaining in the process chamber  201  or HCDS gas which remains after contributing to the formation of the titanium-containing layer is excluded from the process chamber  201 . At this time, with the valves  243   e ,  243   f  and  243   g  opened, the supply of the N 2  gas, as an inert gas, into the process chamber  201  is maintained. The N 2  gas acts as a purge gas, which is capable of further improving the effect of excluding the unreacted HCDS gas remaining in the process chamber  201  or the HCDS gas which remains after contributing to the formation of the silicon-containing layer from the process chamber  201 . The residual gas in the process chamber  201  may not be completely excluded and the interior of the process chamber  201  may not be completely purged. If an amount of the residual gas in the process chamber  201  is very small, this has no adverse effect on the subsequent Step 2. In this case, there is no need to provide a high flow rate of the N 2  gas supplied into the process chamber  201 . For example, the same volume of the N 2  gas as the reaction tube  203  (the process chamber  201 ) may be supplied into the process chamber  201  to purge the interior of the process chamber  201  to such a degree that this has no adverse effect on Step 2. In this way, when the interior of the process chamber  201  is not completely purged, purge time can be shortened, thereby improving a throughput. This can also limit consumption of the N 2  gas to the minimum required for purging. 
     Examples of the chlorosilane-based raw material gas may include inorganic raw material gases such as a tetrachlorosilane or silicon tetrachloride (SiCl 4 , STC) gas, a trichlorosilane (SiHCl 3 , TCS) gas, a dichlorosilane (SiH 2 Cl 2 , DCS) gas, a monochlorosilane (SiH 3 Cl, MCS) gas and the like, in addition to a hexachlorodisilane (Si 2 Cl 6 ) gas. Examples of the inert gas may include rare gases such as an Ar gas, a He gas, a Ne gas, a Xe gas and the like, in addition to the N 2  gas. 
     &lt;Step 2&gt; 
     &lt;TEA Gas Supply&gt; 
     After Step 1 is completed to remove the residual gas from the process chamber  201 , the valve  243   b  of the second gas supply pipe  232   b  is opened to flow a TEA gas into the second gas supply pipe  232   b . A flow rate of the TEA gas flowing into the second gas supply pipe  232   b  is regulated by the mass flow controller  241   b . The TEA gas with its flow rate regulated is supplied from the gas supply holes  250   b  of the second nozzle  249   b  into the process chamber  201 . The TEA gas supplied into the process chamber  201  is activated by heat and is exhausted from the exhaust pipe  231 . At this time, the TEA gas activated by heat is supplied to the wafers  200 . At the same time, the valve  243   f  is opened to flow the N 2  gas as an inert gas into the second inert gas supply pipe  232   f . A flow rate of the N 2  gas flowing into the second inert gas supply pipe  232   f  is regulated by the mass flow controller  241   f . The N 2  gas with its flow rate regulated is supplied into the process chamber  201 , along with the TEA gas, and is exhausted from the exhaust pipe  231 . At this time, in order to prevent the TEA gas from being introduced into the first nozzle  249   a  and the third nozzle  249   c , the valves  243   e  and  243   g  are opened to flow the N 2  gas into the first inert gas supply pipe  232   e  and the third inert gas supply pipe  232   g . The N 2  gas is supplied into the process chamber  201  via the first gas supply pipe  232   a , the third gas supply pipe  232   c , the first nozzle  249   a  and the third nozzle  249   c  and is exhausted from the exhaust pipe  231 . 
     At this time, the APC valve  244  is appropriately regulated to set the internal pressure of the process chamber  201  to fall within a range of, for example, 1 to 13300 Pa, preferably 399 to 3990 Pa. When the internal pressure of the process chamber  201  is set to such a relatively high range of pressure, the TEA gas can be thermally activated by non-plasma. Such thermal activation of the TEA gas may cause a soft reaction which may result in soft modification, as will be described later. The flow rate of TEA gas controlled by the mass flow controller  241   b  is set to fall within a range of, for example, 100 to 2000 sccm. The flow rates of N 2  gases controlled by the mass flow controllers  241   f ,  241   e  and  241   g  are set to fall within a range of, for example, 100 to 10000 sccm. A partial pressure of the TEA gas in the process chamber  201  is set to fall within a range of, for example, 0.01 to 12667 Pa. The time period during which the thermally-activated TEA gas is supplied to the wafers  200 , that is, gas supply time (irradiation time), is set to fall within a range of, for example, 1 to 120 seconds, preferably 1 to 60 seconds. At this time, the heater  207  is set to a temperature such that the temperature of the wafers  200  is set to fall within a range of, for example, 250 to 700 degrees C., preferably 350 to 650 degrees C., as in Step 1. 
     The supply of TEA gas results in reaction of the silicon-containing layer formed on the wafers  200  in Step 1 with the TEA gas. This reaction allows the silicon-containing layer to be changed (modified) to a first layer containing silicon (Si), nitrogen (N) and carbon (C). The first layer is a layer which contains Si, N and C and has a thickness ranging from less than one atom layer to several atom layers. The first layer has a relatively high percentage of Si and C ingredients, i.e., Si-rich as well as C-rich. Chlorine (Cl) contained in the silicon-containing layer or hydrogen contained in the TEA gas upon forming the Si, N and C-containing layer as the first layer forms a gaseous material such as, for example, a chlorine (Cl 2 ) gas, a hydrogen (H 2 ) gas, a hydrogen chloride (HCl) gas or the like in the course of modification reaction of the silicon-containing layer by the TEA gas and is discharged out of the process chamber  201  via the exhaust pipe  231 . 
     &lt;Residual Gas Removal&gt; 
     After the first layer is formed, the valve  243   b  of the second gas supply pipe  232   b  is closed to stop the supply of the TEA gas. At this time, with the APC valve  244  of the exhaust pipe  231  opened, the interior of the process chamber  201  is vacuum-exhausted by the vacuum pump  246  and unreacted TEA gas remaining in the process chamber  201  or TEA gas which remains after contributing to the formation of the first layer, and reactive by-products are excluded from the process chamber  201 . 
     As described above, in the film forming sequence of this embodiment, the internal pressure of the process chamber  201  in the process of supplying the TEA gas is set to be relatively high, for example, higher than the internal pressure of the process chamber  201  in the process of supplying the HCDS gas or may be higher than the internal pressure of the process chamber  201  in a process of supplying an O 2  gas, which will be described later. In this way, when the residual gas is removed after performing the process of supplying the TEA gas with the internal pressure of the process chamber  201  set to be relatively high, that is, the process of exhausting the TEA gas remaining in the process chamber  201  with the supply of the TEA gas stopped, is performed, a large amount and high concentration of the TEA gas is exhausted into the exhaust line at one time. When HCDS gas remaining in the downstream side of the vacuum pump  246  in the exhaust line, in particular in a portion between the trap device  247  and the harm-removing device  248  reacts with the large amount of the TEA gas exhausted at one time, a large amount of reaction byproducts is produced which is likely to block the exhaust line. That is, exhausting the large amount and high concentration of the TEA gas at one time in an exhaust initial stage of the process of exhausting the TEA gas remaining in the process chamber  201  with the supply of the TEA gas stopped may be one of the causes of producing a large amount of reaction byproducts in the downstream side of the vacuum pump  246  in the exhaust line. 
     In this embodiment, in order to prevent the large amount and high concentration of the TEA gas from being exhausted at one time in the exhaust initial stage of the process of exhausting the TEA gas remaining in the process chamber  201  with the supply of the TEA gas stopped, exhaust of the interior of the process chamber  201  is performed in multiple stages by performing a first residual TEA gas exhaust process (first residual gas removal process) of exhausting the TEA gas remaining in the process chamber  201  with a degree of valve opening of the APC valve  244  as a first degree of valve opening and a second residual TEA gas exhaust process (second residual gas removal process) of exhausting the TEA gas remaining in the process chamber  201  with a degree of valve opening of the APC valve  244  as a second degree of valve opening which is higher than the first degree of valve opening, in this order. 
     &lt;First Residual Gas Removal&gt; 
     First, in the first residual TEA gas exhaust process, exhaust capability of the exhaust line is set to first exhaust capability with the degree of valve opening of the APC valve  244  as the first degree of valve opening. As used herein, the term “first degree of valve opening” refers to a degree of valve opening of the APC valve  244  when the set internal pressure (target pressure) of the process chamber  201  is set to a first set pressure, for example, a pressure in a range of 399 to 2600 Pa. For example, this refers to a degree of valve opening which is narrower (smaller) than a degree of valve opening when the APC valve  244  is full-opened. When the degree of valve opening of the APC valve  244  is adjusted, e.g., to a narrower degree of valve opening, the TEA gas remaining in the process chamber  201  is gradually exhausted such that the actual internal pressure of the process chamber  201  approaches the first set internal pressure. The time period during which the interior of the process chamber  201  is exhausted with the degree of valve opening of the APC valve  244  as the first degree of valve opening, that is, a time period of the first residual TEA gas exhaust process, refers to the time period required for the TEA gas remaining in the process chamber  201  to have a concentration which is low enough to provide no significant reaction with the residual HCDS gas even when the TEA gas is exhausted at one time. For example, this time period is set to fall within a range of 5 to 60 seconds. The heater  207  is set to the same temperature as in Step 1. 
     &lt;Second Residual Gas Removal&gt; 
     Next, in the second residual TEA gas exhaust process, exhaust capability of the exhaust line is set to a second exhaust capability, which is higher than the first exhaust capability, with the degree of valve opening of the APC valve  244  as the second degree of valve opening, e.g., one that is higher than the first degree of valve opening. As used herein, the term “second degree of valve opening” refers to a degree of valve opening of the APC valve  244  when the set internal pressure of the process chamber  201  is set to a second set pressure, for example, a pressure in a range of 2 to 1330 Pa. For example, this refers to a degree of valve opening when the APC valve  244  is fully-opened. When the degree of valve opening of the APC valve  244  is adjusted to such a wide (large) degree of valve opening, the low concentration TEA gas remaining in the process chamber  201  is exhausted at one time such that the actual internal pressure of the process chamber  201  approaches the second set internal pressure. The time period during which the interior of the process chamber  201  is exhausted with the degree of valve opening of the APC valve  244  as the second degree of valve opening, that is, a time period of the second residual TEA gas exhaust process, refers to the time period required for unreacted TEA gas remaining in the process chamber  201  or TEA gas which remains after contributing to the formation of the first layer, and reactive by-products to be excluded from the process chamber  201 . For example, this time period is set to fall within a range of 5 to 60 seconds. The heater  207  is set to the same temperature as in Step 1. 
     In this way, in the exhaust initial stage of exhausting the TEA gas remaining in the process chamber  201  with the supply of the TEA gas stopped (the first residual TEA gas exhaust process), the high concentration TEA gas is gradually exhausted to reduce a probability of reaction of the HCDS and TEA gases remaining in the downstream side of the vacuum pump  246  in the exhaust line. Then, at the point of time when the concentration of the TEA gas in the process chamber  201  is lowered enough to provide no significant reaction with the residual HCDS gas even when the TEA gas is exhausted at one time, the remaining TEA gas is exhausted at one time (second residual TEA gas exhaust process). This makes it possible to reduce a probability of reaction of the HCDS and TEA gases remaining in the downstream side of the vacuum pump  246  in the exhaust line in either the first residual TEA gas exhaust process or the second residual TEA gas exhaust process, thereby preventing a large amount of reaction byproducts from being produced in the downstream side of the vacuum pump  246  in the exhaust line. 
     In addition, in both of the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, the supply of the N 2  gas as the inert gas remains with the valves  243   f ,  243   e  and  243   g  opened. In this way, when the N 2  gas as the inert gas is supplied into the process chamber  201  in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, a partial pressure of the TEA gas in the exhausted gas can be lowered. In addition, when the N 2  gas as the inert gas is continuously supplied into the process chamber  201  in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, the partial pressure of the TEA gas in the exhausted gas can remain lowered. This makes it possible to further reduce a probability of reaction of the HCDS and TEA gases remaining in the downstream side of the vacuum pump  246  in the exhaust line in either the first residual TEA gas exhaust process or the second residual TEA gas exhaust process, thereby further preventing a large amount of reaction byproducts from being produced in the downstream side of the vacuum pump  246  in the exhaust line. Flow rates of the N 2  gases controlled by the mass flow controllers  241   f ,  241   e  and  241   g  are set to fall within a range of, for example, 100 to 5000 sccm. 
     The N 2  gases supplied in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process act as purge gases by which unreacted TEA gas remaining in the process chamber  201  or TEA gas which remains after contributing to the formation of the first layer, and reactive by-products can be excluded from the process chamber  201  more effectively. However, in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, the residual gas in the process chamber  201  may not be completely excluded and the interior of the process chamber  201  may not be completely purged. If an amount of the residual gas in the process chamber  201  is very small, this has no adverse effect on the subsequent Step 3. In this case, there is no need to provide a high flow rate of the N 2  gas supplied into the process chamber  201 . For example, the same volume of the N 2  gas as the reaction tube  203  (the process chamber  201 ) may be supplied into the process chamber  201  to purge the interior of the process chamber  201  to such a degree that this has no adverse effect on Step 3. In this way, when the interior of the process chamber  201  is not completely purged, purge time can be shortened, thereby improving a throughput. This can also limit consumption of the N 2  gas to the minimum required for purging. 
     Examples of the amine-based gas may preferably include, in addition to a triethylamine ((C 2 H 5 ) 3 N, TEA) gas, an ethylamine-based gas such as a diethylamine ((C 2 H 5 ) 2 NH, DEA) gas, a monoethylamine (C 2 H 5 NH 2 , MEA) gas or the like, a methylamine-based gas such as trimethylamine ((CH 3 ) 3 N, TMA) gas, a dimethylamine ((CH 3 ) 2 NH, DMA) gas, a monomethylamine (CH 3 NH 2 , MMA) gas or the like, a propylamine-based gas such as a tripropylamine ((C 3 H 7 ) 3 N, TPA) gas, a dipropylamine ((C 3 H 7 ) 2 NH, DPA) gas, a monopropylamine (C 3 H 7 NH 2 , MPA) gas or the like, an isopropylamine-based gas such as a triisopropylamine ([(CH 3 ) 2 CH] 3 N, TIPA) gas, a diisopropylamine ([(CH 3 ) 2 CH] 2 NH, DIPA) gas, a monoisopropylamine ((CH 3 ) 2 CHNH 2 , MIPA) gas or the like, a butylamine-based gas such as a tributylamine ((C 4 H 9 ) 3 N, TBA) gas, a dibutylamine ((C 4 H 9 ) 2 NH, DBA) gas, a monobutylamine (C 4 H 9 NH 2 , MBA) gas or the like, or an isobutylamine-based gas such as a triisobutylamine ([(CH 3 ) 2 CHCH 2 ] 3 N, TIBA) gas, a diisobutylamine ([(CH 3 ) 2 CHCH 2 ] 2 NH, DIBA) gas, a monoisobutylamine ((CH 3 ) 2 CHCH 2 NH 2 , MIBA) gas or the like. That is, examples of the amine-based gas may preferably include at least one gas of (C 2 H 5 ) x NH 3-x , (CH 3 ) x NH 3-x , (C 3 H 7 ) x NH 3-x , [(CH 3 ) 2 CH] x NH 3-x  and (C 4 H 9 ) x NH 3-x , [(CH 3 ) 2 CHCH 2 ] x NH 3-x  (where, x is an integer from 1 to 3). Examples of the inert gas may include rare gases such as an Ar gas, a He gas, a Ne gas, a Xe gas and the like, in addition to the N 2  gas. 
     &lt;Step 3&gt; 
     After Step 2 is completed to remove the residual gas from the process chamber  201 , the valve  243   c  of the third gas supply pipe  232   c  is opened to flow an O 2  gas into the third gas supply pipe  232   c . A flow rate of the O 2  gas flowing into the third gas supply pipe  232   c  is regulated by the mass flow controller  241   c . The O 2  gas with its flow rate regulated is supplied from the gas supply holes  250   c  of the third nozzle  249   c  into the process chamber  201 . The O 2  gas supplied into the process chamber  201  is activated by heat and is exhausted from the exhaust pipe  231 . At this time, the O 2  gas activated by heat is supplied to the wafers  200 . At the same time, the valve  243   g  is opened to flow N 2  gas into the third inert gas supply pipe  232   g . The N 2  gas is supplied into the process chamber  201 , along with the O 2  gas, and is exhausted from the exhaust pipe  231 . At this time, in order to prevent the O 2  gas from being introduced into the first nozzle  249   a  and the second nozzle  249   b , the valves  243   e  and  243   f  are opened to flow the N 2  gas into the first inert gas supply pipe  232   e  and the second inert gas supply pipe  232   f . The N 2  gas is supplied into the process chamber  201  via the first gas supply pipe  232   a , the second gas supply pipe  232   b , the first nozzle  249   a  and the second nozzle  249   b  and is exhausted from the exhaust pipe  231 . 
     At this time, the APC valve  244  is appropriately regulated to set the internal pressure of the process chamber  201  to fall within a range of, for example, 1 to 3000 Pa. When the internal pressure of the process chamber  201  is set to such a relatively high range of pressure, the O 2  gas can be thermally activated by non-plasma. Such thermal activation of the O 2  gas may cause a soft reaction which may result in soft modification. The flow rate of O 2  gas controlled by the mass flow controller  241   c  is set to fall within a range of, for example, 100 to 10000 sccm. The flow rates of N 2  gases controlled by the mass flow controllers  241   g ,  241   e  and  241   f  are set to fall within a range of, for example, 100 to 10000 sccm. A partial pressure of the O 2  gas in the process chamber  201  is set to fall within a range of, for example, 0.01 to 2970 Pa. The time period during which the thermally-activated O 2  gas is supplied to the wafers  200 , that is, gas supply time (irradiation time), is set to fall within a range of, for example, 1 to 120 seconds, preferably 1 to 60 seconds. At this time, the heater  207  is set to a temperature such that the temperature of the wafers  200  is set to fall within a range of, for example, 250 to 700 degrees C., preferably 350 to 650 degrees C., as in Steps 1 and 2. 
     At this time, a gas flown into the process chamber  201  is only the O 2  gas thermally activated by the high internal pressure of the process chamber  201  rather than the HCDS gas and the TEA gas. Therefore, the activated O 2  gas reacts with at least a portion of the Si, N and C-containing first layer formed on the wafers  200  in Step 2, without causing any gaseous reaction. This allows the first layer to be oxidized to be modified into a silicon oxycarbonitride layer (SiOCN layer) or a silicon oxycarbide layer (SiOC layer) as the second layer. 
     In addition, when the thermally-activated O 2  gas is flown into the process chamber  201 , the first layer can be thermally oxidized to be modified (changed) into the SiOCN layer or the SiOC layer. At this time, the first layer is modified into the SiOCN layer or the SiOC layer while oxygen (O) ingredients are being added to the first layer. In addition, thermal oxidation by the O 2  gas increases a Si—O bond in the first layer, while decreasing a Si—N bond, a Si—C bond and a Si—Si bond, thereby providing a reduced percentage of N, C and Si ingredients in the first layer. In this case, when thermal oxidation time is extended or an oxidizing power in the thermal oxidation is increased, most of the N ingredients can be separated to reduce the N ingredients up to a level of impurity or substantially remove the N ingredients. That is, the first layer can be modified into the SiOCN layer or the SiOC layer while changing a composition ratio in such a manner that the oxygen concentration is increased whereas the nitrogen, carbon and silicon concentrations are decreased. In addition, when process conditions such as the internal pressure of the process chamber  201 , gas supply time and so on are controlled, a percentage of oxygen (O) ingredients in the SiOCN layer or the SiOC layer, that is, the oxygen concentration, can be minutely adjusted and a composition ratio of the SiOCN layer or the SiOC layer can be more precisely controlled. 
     In addition, it is clear that the C ingredients in the first layer formed in Steps 1 and 2 are rich compared to the N ingredients. For example, some experiments showed that the carbon concentration is two times or more as high as the nitrogen concentration. That is, by stopping the oxidation before completely separating the N ingredients from the first layer by virtue of the thermal oxidation by the O 2  gas, i.e., under a state where the N ingredients remain, the C and N ingredients are left in the first layer, which leads to modification of the first layer into the SiOCN layer. In addition, even in the phase where most of the N ingredients in the first layer are completely separated by virtue of the thermal oxidation by the O 2  gas, the C ingredients are left in the first layer and the first layer is modified into the SiOC layer by stopping the oxidation under this state. That is, when gas supply time (oxidation time) or an oxidizing power is controlled, a percentage of C ingredients, i.e., the carbon concentration, can be controlled and one of the SiOCN layer and the SiOC layer can be formed while controlling its composition ratio. In addition, when process conditions such as the internal pressure of the process chamber  201 , gas supply time and so on are controlled, a percentage of oxygen (O) ingredients in the SiOCN layer or the SiOC layer, that is, the oxygen concentration, can be minutely adjusted and a composition ratio of the SiOCN layer or the SiOC layer can be more precisely controlled. 
     At this time, it is preferable that the oxidation reaction of the first layer is not saturated. For example, when the first layer having a thickness of one atom layer or less is formed in Steps 1 and 2, it is preferable to oxidize a portion of the first layer. In this case, the oxidation is performed in such a manner that the oxidation reaction of the first layer is unsaturated in order to prevent the entire first layer having the thickness of one atom layer or less from being oxidized. 
     Although the unsaturation of the oxidation reaction of the first layer may be achieved under the above-mentioned process conditions employed in Step 3, it can be more easily achieved by changing the above-mentioned process conditions of Step 3 to the following process conditions. 
     Wafer temperature: 500 to 650 degrees C. 
     Internal pressure of process chamber: 133 to 2666 Pa 
     O 2  gas partial pressure: 33 to 2515 Pa 
     Flow rate of supplied O 2  gas: 1000 to 5000 sccm 
     Flow rate of supplied N 2  gas: 300 to 3000 sccm 
     O 2  gas supply time: 6 to 60 seconds 
     Thereafter, the valve  243   c  of the third gas supply pipe  232   c  is closed to stop the supply of the O 2  gas. At this time, with the APC valve  244  of the exhaust pipe  231  opened, the interior of the process chamber  201  is vacuum-exhausted by the vacuum pump  246  and unreacted O 2  gas remaining in the process chamber  201  or O 2  gas which remains after contributing to the formation of the second layer and reaction byproducts are excluded from the process chamber  201 . At this time, with the valves  243   g ,  243   e  and  243   f  opened, the supply of the N 2  gas into the process chamber  201  is maintained. The N 2  gas acts as purge gas which is capable of improving the effect of excluding the unreacted O 2  gas remaining in the process chamber  201  or the O 2  gas which remains after contributing to the formation of the second layer and the reaction byproducts from the process chamber  201 . The residual gas in the process chamber  201  may not be completely excluded and the interior of the process chamber  201  may not be completely purged. If an amount of the residual gas in the process chamber  201  is very small, this has no adverse effect on the subsequent Step 1. In this case, there is no need to provide a high flow rate of the N 2  gas supplied into the process chamber  201 . For example, the same volume of the N 2  gas as the reaction tube  203  (the process chamber  201 ) may be supplied into the process chamber  201  to purge the interior of the process chamber  201  to such a degree that this has no adverse effect on Step 1. In this way, when the interior of the process chamber  201  is not completely purged, purge time can be shortened, thereby improving a throughput. This can also limit consumption of the N 2  gas to the minimum required for purging. 
     Examples of the oxygen-containing gas may include nitrous oxide (N 2 O) gas, nitrogen monoxide (NO) gas, nitrogen dioxide (NO 2 ) gas, ozone (O 3 ) gas, hydrogen (H 2 ) gas+oxygen (O 2 ) gas, H 2  gas+O 3  gas, vapour (H 2 O) gas, carbon monoxide (CO) gas, carbon dioxide (CO 2 ) gas and the like, in addition to O 2  gas. Examples of the inert gas may include rare gases such as Ar gas, He gas, Ne gas, Xe gas and the like, in addition to N 2  gas. 
     When one cycle including the above-described Steps 1 to 3 is performed once or more (predetermined number of times), a silicon oxycarbonitride film (SiOCN film) or a silicon oxycarbide film (SiOC film) having a predetermined composition and thickness can be formed on the wafers  200 . This cycle may be preferably performed several times rather than once. That is, a thickness of the SiOCN layer or SiOC layer formed per cycle may be set to be smaller than a desired thickness and the cycle may be repeated several times until the SiOCN layer or SiOC layer reaches the desired thickness. 
     &lt;Purge and Return to Atmospheric Pressure&gt; 
     Once the film formation process of forming the silicon oxycarbonitride film or silicon oxycarbide film having the predetermined composition and thickness is completed, the valves  243   e ,  243   f  and  243   g  are opened and N 2  gases as inert gases are supplied from the respective first inert gas supply pipe  232   e , second inert gas supply pipe  232   f , and third inert gas supply pipe  232   g  into the process chamber  201  and are exhausted from the exhaust pipe  231  such that the interior of the process chamber  201  is purged by the inert gases (gas purge), thereby removing gas remaining in the process chamber  201  and reaction byproducts from the process chamber  201 . Thereafter, the internal atmosphere of the process chamber  201  is substituted with the inert gas (inert gas substitution) and the internal pressure of the process chamber  201  returns to the atmospheric pressure (return to atmospheric pressure). 
     &lt;Boat Unload and Wafer Discharge&gt; 
     Thereafter, the seal cap  219  is descended by the boat elevator  115  to open the bottom of the reaction tube  203  while carrying the processed wafers  200  from the bottom of the reaction tube  203  out of the reaction tube  203  with them supported by the boat  217  (boat unload). Thereafter, the processed wafers  200  are discharged out of the boat  217  (wafer discharge). 
     (3) Certain Advantages 
     According to this embodiment, in the exhaust initial stage of the process of exhausting the TEA gas remaining in the process chamber  201  with the supply of the TEA gas stopped (the first residual TEA gas exhaust process), the high concentration TEA gas is gradually exhausted to reduce a probability of reaction of the HCDS and TEA gases remaining in the downstream side of the vacuum pump  246  in the exhaust line. Then, at the point of time when the concentration of the TEA gas in the process chamber  201  is lowered enough to provide no significant reaction with the residual HCDS gas even when the TEA gas is exhausted at one time, the remaining TEA gas is exhausted at one time (second residual TEA gas exhaust process). This makes it possible to reduce a probability of reaction of the HCDS and TEA gases remaining in the downstream side of the vacuum pump  246  in the exhaust line in either the first residual TEA gas exhaust process or the second residual TEA gas exhaust process, thereby preventing a large amount of reaction byproducts from being produced in the downstream side of the vacuum pump  246  in the exhaust line. 
     In addition, according to this embodiment, when the N 2  gas as the inert gas is supplied into the process chamber  201  in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, a partial pressure of the TEA gas in the exhausted gas can be lowered. In addition, when the N 2  gas as the inert gas is continuously supplied into the process chamber  201  in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, the partial pressure of the TEA gas in the exhausted gas can remain lowered. This makes it possible to further reduce a probability of reaction of the HCDS and TEA gases remaining in the downstream side of the vacuum pump  246  in the exhaust line in either the first residual TEA gas exhaust process or the second residual TEA gas exhaust process, thereby further preventing a large amount of reaction byproducts from being produced in the downstream side of the vacuum pump  246  in the exhaust line. 
     As a result, according to this embodiment, it is possible to prevent a back pressure of the vacuum pump  246 , that is, an internal pressure of the exhaust pipe  231  in the downstream side of the vacuum pump  246 , from increasing when the SiOCN film or SiOC film is formed on the wafers  200 . This may lead to precise and quick control of the internal pressure of the process chamber  201  and hence improvement of quality and productivity of substrate processing. In addition, since reaction byproducts are prevented from being deposited onto the exhaust pipe  231 , the frequency of maintenance of the exhaust line can be reduced and the productivity of substrate processing apparatuses can be improved. 
     In addition, according to this embodiment, the above-described advantages can be achieved without having to increase the exhaust capability of the vacuum pump  246  or heat the exhaust pipe  231 . That is, the above-described advantages can be achieved only by changing an exhaust sequence when the residual TEA gas in the process chamber is exhausted, without having to make a significant change in the physical configuration of the substrate processing apparatus  100 . This may result in effective reduction of costs for substrate processing. 
     &lt;Second Embodiment&gt; 
     Next, a second embodiment of the present disclosure will be described. 
     While an example of using the oxygen-containing gas (O 2  gas) as a reaction gas to form a silicon oxycarbonitride film or a silicon oxycarbide film having a predetermined composition and thickness on the wafers  200  has been illustrated in the first embodiment, an example of using a nitrogen-containing gas (NH 3  gas) as a reaction gas to form a silicon carbonitride film having a predetermined composition and thickness on the wafers  200  will be now illustrated in a second embodiment. 
     Specifically, the second embodiment provides an example of forming a silicon carbonitride film (SiCN film) having a predetermined composition and thickness on the wafers  200  by performing a cycle including a process of forming a silicon-containing layer on the wafer  200  by supplying a raw material gas (HCDS gas) to the heated wafer  200  in the process chamber  201 , exhausting the HCDS gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the HCDS gas is stopped , modifying the silicon-containing layer to form a first layer containing silicon, nitrogen and carbon by supplying an amine-based gas (TEA gas) to the heated wafer  200  in the process chamber  201 , exhausting the TEA gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the TEA gas is stopped, modifying the first layer to form a silicon oxycarbonitride layer as a second layer by supplying a nitrogen-containing gas (NH 3  gas) as a reaction gas different from the HCDS gas and TEA gas to the heated wafer  200  in the process chamber  201 , and exhausting the NH 3  gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the NH 3  gas is stopped, by a predetermined number of times (n times). 
       FIG. 6  is a flow chart illustrating a film forming flow according to this second embodiment.  FIG. 7  is a timing diagram illustrating a timing of gas being supplied in a film forming sequence according to this second embodiment. This second embodiment has the same configuration as the first embodiment except that the former uses thermally-activated NH 3  gas as a reaction gas in Step 3. That is, the second embodiment has the same configuration as the first embodiment in that, when the TEA gas remaining in the process chamber  201  is exhausted with the supply of the TEA gas stopped in Step 2, the first residual TEA gas exhaust process of exhausting the TEA gas remaining in the process chamber  201  with the degree of valve opening of the APC valve  244  as the first degree of valve opening and the second residual TEA gas exhaust process of exhausting the TEA gas remaining in the process chamber  201  with the degree of valve opening of the APC valve  244  as the second degree of valve opening which is higher than the first degree of valve opening are performed in this order. Step 3 of this embodiment will be described below. 
     &lt;Step 3&gt; 
     After Step 2 is completed to remove the residual gas from the process chamber  201 , the valve  243   d  of the fourth gas supply pipe  23   d  is opened to flow the NH 3  gas into the fourth gas supply pipe  232   d . A flow rate of the NH 3  gas flowing into the fourth gas supply pipe  232   d  is regulated by the mass flow controller  241   d . The NH 3  gas with its flow rate regulated is supplied from the gas supply holes  250   c  of the third nozzle  249   c  into the process chamber  201 . The NH 3  gas supplied into the process chamber  201  is activated by heat and is exhausted from the exhaust pipe  231 . At this time, the NH 3  gas activated by heat is supplied to the wafers  200 . At the same time, the valve  243   g  is opened to flow N 2  gas into the third inert gas supply pipe  232   g . The N 2  gas is supplied into the process chamber  201 , along with the NH 3  gas, and is exhausted from the exhaust pipe  231 . At this time, in order to prevent the NH 3  gas from being introduced into the first nozzle  249   a  and the second nozzle  249   b , the valves  243   e  and  243   f  are opened to flow the N 2  gas into the first inert gas supply pipe  232   e  and the second inert gas supply pipe  232   f . The N 2  gas is supplied into the process chamber  201  via the first gas supply pipe  232   a , the second gas supply pipe  232   b , the first nozzle  249   a  and the second nozzle  249   b  and is exhausted from the exhaust pipe  231 . 
     At this time, the APC valve  244  is appropriately regulated to set the internal pressure of the process chamber  201  to fall within a range of, for example, 1 to 3000 Pa. When the internal pressure of the process chamber  201  is set to such a relatively high range of pressure, the NH 3  gas can be thermally activated by non-plasma. Such thermal activation of the NH 3  gas may cause a soft reaction which may result in soft modification which will be described later. The flow rate of NH 3  gas controlled by the mass flow controller  241   c  is set to fall within a range of, for example, 100 to 10000 sccm. The flow rates of N 2  gases controlled by the mass flow controllers  241   g ,  241   e  and  241   f  are set to fall within a range of, for example, 100 to 10000 sccm. A partial pressure of the NH 3  gas in the process chamber  201  is set to fall within a range of, for example, 0.01 to 2970 Pa. The time period during which the thermally-activated NH 3  gas is supplied to the wafers  200 , that is, gas supply time (irradiation time), is set to fall within a range of, for example, 1 to 120 seconds, preferably 1 to 60 seconds. At this time, the heater  207  is set to a temperature such that the temperature of the wafers  200  is set to fall within a range of, for example, 250 to 700 degrees C., preferably 350 to 650 degrees C., as in Steps 1 and 2. 
     At this time, a gas flown into the process chamber  201  is only the NH 3  gas thermally activated by the high internal pressure of the process chamber  201  rather than the HCDS gas and the TEA gas. Therefore, the activated NH 3  gas reacts with at least a portion of the Si, N and C-containing first layer formed on the wafers  200  in Step 2, without causing any gaseous reaction. This allows the first layer to be nitrified to be modified into a silicon oxycarbonitride layer (SiCN layer) as the second layer. 
     In addition, when the thermally-activated NH 3  gas is flown into the process chamber  201 , the first layer can be thermally nitrified to be modified (changed) into the SiCN layer. At this time, the first layer is modified into the SiCN layer while a percentage of nitrogen (N) ingredients in the first layer is being increased. In addition, thermal nitrification by the NH 3  gas increases a Si—N bond in the first layer, while decreasing a Si—C bond and a Si—Si bond, thereby providing a reduced percentage of C and Si ingredients in the first layer. That is, the first layer can be modified into the SiCN layer while changing a composition ratio in such a manner that the nitrogen concentration is increased whereas the carbon and silicon concentrations are decreased. In addition, when process conditions such as the internal pressure of the process chamber  201 , gas supply time and so on are controlled, a percentage of nitrogen (N) ingredients in the SiCN layer, that is, the nitrogen concentration, can be minutely adjusted and a composition ratio of the SiCN layer can be more precisely controlled. 
     At this time, it is preferable that the nitrification reaction of the first layer is not saturated. For example, when the first layer having a thickness of one atom layer or less is formed in Steps 1 and 2, it is preferable to oxidize a portion of the first layer. In this case, the nitrification is performed in such a manner that the nitrification reaction of the first layer is unsaturated in order to prevent the entire first layer having the thickness of one atom layer or less from being oxidized. 
     Although the unsaturation of the nitrification reaction of the first layer may be achieved under the above-mentioned process conditions employed in Step 3, it can be more easily achieved by changing the above-mentioned process conditions of Step 3 to the following process conditions. 
     Wafer temperature: 500 to 650 degrees C. 
     Internal pressure of process chamber: 133 to 2666 Pa 
     NH 3  gas partial pressure: 33 to 2515 Pa 
     Flow rate of supplied NH 3  gas: 1000 to 5000 sccm 
     Flow rate of supplied N 2  gas: 300 to 3000 sccm 
     NH 3  gas supply time: 6 to 60 seconds 
     Thereafter, the valve  243   d  of the fourth gas supply pipe  232   d  is closed to stop the supply of the NH 3  gas. At this time, with the APC valve  244  of the exhaust pipe  231  opened, the interior of the process chamber  201  is vacuum-exhausted by the vacuum pump  246  and unreacted NH 3  gas remaining in the process chamber  201  or NH 3  gas which remains after contributing to the formation of the second layer and reaction byproducts are excluded from the process chamber  201 . At this time, with the valves  243   g ,  243   e  and  243   f  opened, the supply of the N 2  gas into the process chamber  201  is maintained. The N 2  gas acts as purge gas which is capable of improving the effect of excluding the unreacted NH 3  gas remaining in the process chamber  201  or the NH 3  gas which remains after contributing to the formation of the second layer and the reaction byproducts from the process chamber  201 . The residual gas in the process chamber  201  may not be completely excluded and the interior of the process chamber  201  may not be completely purged. If an amount of the residual gas in the process chamber  201  is very small, this has no adverse effect on the subsequent Step 1. In this case, there is no need to provide a high flow rate of the N 2  gas supplied into the process chamber  201 . For example, the same volume of the N 2  gas as the reaction tube  203  (the process chamber  201 ) may be supplied into the process chamber  201  to purge the interior of the process chamber  201  to such a degree that this has no adverse effect on Step 1. In this way, when the interior of the process chamber  201  is not completely purged, purge time can be shortened, thereby improving a throughput. This can also limit consumption of the N 2  gas to the minimum required for purging. 
     Examples of the nitrogen-containing gas may include diazine (N 2 H 2 ) gas, hydrazine (N 2 H 4 ) gas, N 3 H 8  gas, gas containing compounds thereof and the like, in addition to the NH 3  gas. Examples of the inert gas may include rare gases such as an Ar gas, a He gas, a Ne gas, a Xe gas and the like, in addition to the N 2  gas. 
     When one cycle including the above-described Steps 1 to 3 is performed once or more (e.g., a predetermined number of times), a silicon oxycarbonitride film (SiCN film) having a predetermined composition and thickness can be formed on the wafers  200 . This cycle may be preferably performed several times rather than once. That is, a thickness of the SiCN layer formed per cycle may be set to be smaller than a desired thickness and the cycle may be repeated several times until the SiCN layer reaches the desired thickness. 
     The second embodiment, as described, has the same effects as the first embodiment. That is, when the TEA gas remaining in the process chamber  201  is exhausted with the supply of the TEA gas stopped in Step 2, by performing the first residual TEA gas exhaust process of exhausting the TEA gas remaining in the process chamber  201  with the degree of valve opening of the APC valve  244  as the first degree of valve opening and the second residual TEA gas exhaust process of exhausting the TEA gas remaining in the process chamber  201  with the degree of valve opening of the APC valve  244  as the second degree of valve opening, which is higher than the first degree of valve opening, in this order, it is possible to prevent a large amount of reaction byproducts from being produced in the downstream side of the vacuum pump  246  in the exhaust line. In addition, when the N 2  gas is supplied into the process chamber  201  in the first residual TEA gas exhaust process and the second residual TEA gas exhaust process, it is possible to further prevent a large amount of reaction byproducts from being produced in the downstream side of the vacuum pump  246  in the exhaust line. As a result, it is possible to prevent a back pressure of the vacuum pump  246  from increasing when the SiCN film is formed on the wafers  200 . This may lead to precise and quick control of the internal pressure of the process chamber  201  and hence improvement of quality and productivity of substrate processing. In addition, the frequency of maintenance of the exhaust line can be reduced and the productivity of substrate processing apparatuses can be improved. In addition, the above-described advantages can be achieved only by changing an exhaust sequence when the residual TEA gas in the process chamber is exhausted. This may result in effective reduction of costs for substrate processing. 
     &lt;Other Embodiments&gt; 
     Although various embodiments have been described in the above, the present disclosure is not limited to these disclosed embodiments and various modifications and changes may be made without departing from the spirit and scope of the present disclosure. 
     For example, although an example of changing the degree of valve opening of the APC valve  244  in two steps in the process of exhausting the amine-based gas remaining in the process chamber  201  has been illustrated in the above embodiments, the present disclosure is not limited thereto. For example, when exhausting the amine-based gas remaining in the process chamber  201 , the degree of valve opening of the APC valve  244  may be changed in 3, 4, 5 or more steps. That is, the degree of valve opening of the APC valve  244  may be changed in multiple steps. 
     In addition, for example, although an example of supplying the chlorosilane-based raw material gas and the amine-based gas to the wafers  200  in the process chamber  201  in this order when the Si, N and C-containing first layer is formed has been illustrated in the above embodiments, a sequence of supply of these gases may be reversed. That is, the amine-based gas may be first supplied and the chlorosilane-based raw material gas may be then supplied. In other words, one of the chlorosilane-based raw material gas and the amine-based gas is first supplied and the other may be then supplied. Changing the sequence of gas supply in this way allows change in film quality and composition ratio of a film to be formed. 
     In addition, although an example of using the chlorosilane-based raw material gas as raw material gas to form the silicon-containing layer in Step 1 has been illustrated in the above embodiments, the chlorosilane-based raw material gas may be replaced with other silane-based raw material gas having halogen-based ligands. For example, the chlorosilane-based raw material gas may be replaced with fluorosilane-based raw material gas. Here, the fluorosilane-based raw material gas refers to silane-based raw material gas which has fluoro groups as halogen groups and contains at least a silicon (Si) element and a fluorine (F) element. Examples of the fluorosilane-based raw material gas may include silicon fluoride gas such as tetrafluorosilane (or silicon tetrafluoride (SiF 4 )) gas, hexafluorodisilane (Si 2 F 6 ) gas or the like. In this case, the fluorosilane-based raw material gas is supplied to the wafers  200  in the process chamber  201  to form the silicon-containing layer. 
     When a silicon insulating film formed according to the above-described embodiments and their modifications is used as a sidewall spacer, it is possible to provide device forming techniques with small leak current and excellent workability. 
     In addition, when a silicon insulating film formed according to the above-described embodiments and their modifications is used as an etch stopper, it is possible to provide device forming techniques with small leak current and excellent workability. 
     According to the above-described embodiments and their modifications, it is possible to form a silicon insulating film having an ideal stoichiometry without using plasma even in a low temperature region. In addition, since the silicon insulating film can be formed without using plasma, the above-described embodiments and their modifications may be applied to processes which are concerned about plasma damage, such as, for example, forming a SADP film of DPT. 
     In addition, although an example of using a raw material gas, an amine-based gas and an oxygen-containing gas to form a SiOCN film or a SiOC film and an example of using a raw material gas, an amine-based gas and a nitrogen-containing gas to form a SiCN film have been illustrated in the above embodiments, the present disclosure is not limited thereto. For example, the present disclosure may be suitably applied to a case where only a raw material gas and an amine-based gas are used to form a SiCN film. In addition, the present disclosure may be suitably applied to a case where a raw material gas, an amine-based gas and a boron-containing gas are used to form a silicoboron carbonitride film (SiBCN film) or a silicoboron nitride film (SiBN film). Examples of the boron-containing gas may include a boron trichloride (BCl 3 ) gas, to diborane (B 2 H 6 ) as or a borazine-based gas in this way, the present disclosure may be suitably applied to various substrate processing using a raw material and an amine-based gas. 
     In addition, although an example of forming a silicon-containing insulating film such as a silicon oxycarbonitride film (SiOCN film), a silicon oxycarbide film (SiOC), a silicon carbonitride film (SiCN film) has been illustrated in the above embodiments, the present disclosure may be applied to a case where a metal-based film containing metal elements such as, for example, titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), aluminum (Al), molybdenum (Mo) and the like is formed. 
     That is, the present disclosure may be suitably applied to a case where a metal oxycarbonitride film such as a titanium oxycarbonitride film (TiOCN film), a zirconium oxycarbonitride film (ZrOCN film), a hafnium oxycarbonitride film (HfOCN film), a tantalum oxycarbonitride film (TaOCN film), an aluminum oxycarbonitride film (AlOCN film), a molybdenum oxycarbonitride film (MoOCN film) and the like is formed. 
     In addition, the present disclosure may be suitably applied to a case where a metal oxycarbide film such as a titanium oxycarbide film (TiOC film), a zirconium oxycarbide film (ZrOC film), a hafnium oxycarbide film (HfOC film), a tantalum oxycarbide film (TaOC film), an aluminum oxycarbide film (AlOC film), a molybdenum oxycarbide film (MoOC film) and the like is formed. 
     In addition, the present disclosure may be suitably applied to a case where a metal carbonitride film such as a titanium carbonitride film (TiCN film), a zirconium carbonitride film (ZrCN film), a hafnium carbonitride film (HfCN film), a tantalum carbonitride film (TaCN film), an aluminum carbonitride film (AlCN film), a molybdenum carbonitride film (MoCN film) and the like is formed. 
     In this case, instead of the chlorosilane-based raw material gas used in the above embodiments, raw material gas containing a metal element and a halogen element may be used to form a film using the same sequence as the above embodiments. That is, metal-based films (metal oxycarbonitride film, metal oxycarbide film and metal carbonitride film) having a predetermined composition and thickness can be formed on the wafers  200  by performing a cycle including a process of forming a metal-containing layer on the wafer  200  by supplying a raw material gas containing a metal element and a halogen element to the heated wafer  200  in the process chamber  201 , exhausting the raw material gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the raw material gas is stopped , modifying the metal-containing layer to form a first layer containing a metal element, nitrogen and carbon by supplying an amine-based gas to the heated wafer  200  in the process chamber  201 , exhausting the amine-based gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the amine-based gas is stopped, modifying the first layer to form a second layer by supplying a reaction gas different from the raw material gas and the amine-based gas to the heated wafer  200  in the process chamber  201 , and exhausting the reaction gas remaining in the process chamber  201  by means of the exhaust line under a state where the supply of the reaction gas is stopped, by a predetermined number of times (once or more). In this case, like the above embodiments, the degree of valve opening of the APC valve  244  in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber  201 . 
     For example, if metal-based films (TiOCN film, TiOC film and TiCN film) containing Ti is formed, gas containing Ti and chloro groups of titanium tetrachloride (TiCl 4 ) or the like or gas containing Ti and fluoro groups of titanium tetrafluoride (TiF 4 ) or the like may be used as a raw material gas. In this case, the same amine-based gas and reaction gas as in the above embodiments may be used. In addition, the same process conditions as in the above embodiments may be used. 
     For example, if metal-based films (ZrOCN film, ZrOC film and ZrCN film) containing Zr is formed, gas containing Zr and chloro groups of zirconium tetrachloride (ZrCl 4 ) or the like or gas containing Zr and fluoro groups of zirconium tetrafluoride (ZrF 4 ) or the like may be used as a raw material gas. In this case, the same amine-based gas and reaction gas as in the above embodiments may be used. In addition, the same process conditions as in the above embodiments may be used. 
     For example, if metal-based films (HfOCN film, HfOC film and HfCN film) containing Hf is formed, gas containing Hf and chloro groups of hafnium tetrachloride (HfCl 4 ) or the like or gas containing Hf and fluoro groups of hafnium tetrafluoride (HfF 4 ) or the like may be used as a raw material gas. In this case, the same amine-based gas and reaction gas as in the above embodiments may be used. In addition, the same process conditions as in the above embodiments may be used. 
     For example, if metal-based films (TaOCN film, TaOC film and TaCN film) containing Ta is formed, gas containing Ta and chloro groups of tantalum pentachloride (TaCl 5 ) or the like or gas containing Ta and fluoro groups of tantalum pentafluoride (TaF 5 ) or the like may be used as a raw material gas. In this case, the same amine-based gas and reaction gas as in the above embodiments may be used. In addition, the same process conditions as in the above embodiments may be used. 
     For example, if metal-based films (AlOCN film, AlOC film and AlCN film) containing Al is formed, gas containing Al and chloro groups of aluminum trichloride (AlCl 3 ) or the like or gas containing Al and fluoro groups of aluminum trifluoride (AlF 3 ) or the like may be used as a raw material gas. In this case, the same amine-based gas and reaction gas as in the above embodiments may be used. In addition, the same process conditions as in the above embodiments may be used. 
     For example, if metal-based films (MoOCN film, MoOC film and MoCN film) containing Mo is formed, gas containing Mo and chloro groups of molybdenum pentachloride (MoCl 5 ) or the like or gas containing Hf and fluoro groups of hafnium pentafluoride (MoF 5 ) or the like may be used as a raw material gas. In this case, the same amine-based gas and reaction gas as in the above embodiments may be used. In addition, the same process conditions as in the above embodiments may be used. 
     In brief, the present disclosure may be suitably applied to a case where films containing predetermined elements such as semiconductor elements, metal elements and the like are formed. 
     In addition, although the example of forming the films using the batch type substrate processing apparatus to process a plurality of substrates at once has been described in the above embodiments, the present disclosure is not limited thereto but may be suitably applied to film formation using a single type substrate processing apparatus to process a single substrate or several substrates at once. 
     In addition, the above embodiments, modifications and applications may be used in proper combinations. 
     In addition, the present disclosure may be implemented by changing the process recipes of an existing substrate processing apparatus, for example. The change of process recipes may include installing the process recipes of the present disclosure in the existing substrate processing apparatus via a telecommunication line or a recording medium storing the process recipes, and operating the existing substrate processing apparatus to change its process recipes into the process recipes of one or more of the embodiments described. 
     EXAMPLE 
     As an example of the present disclosure, the substrate processing apparatus in the above embodiments was used to repeat a batch process of forming SiOC films on a plurality of wafers several times according to the film forming sequence of the above-described first embodiment. In this example, an HCDS gas was used as a raw material gas, a TEA gas was used as an amine-based gas and an O 2  gas is used as a reaction gas.  FIG. 8A  is a timing diagram of gas supply in a film forming sequence of this example. As shown in  FIG. 8A , the internal pressure of a process chamber was set to 930 Pa for a HCDS gas supply process, 2 Pa for a residual HCDS gas exhaust process, 2660 Pa for a TEA gas supply process, 1330 Pa for a first residual TEA gas exhaust process and 2 Pa for a second residual TEA gas exhaust process. Other film forming conditions (process conditions in each Step) was set to fall within a range of the process conditions described in the above-described first embodiment. 
     As a comparative example, a batch process of forming SiOC films on a plurality of wafers several times according to a film forming sequence of the above-described first embodiment where only the second residual TEA gas exhaust process is performed with the first residual TEA gas exhaust process excluded from the film forming sequence. In this comparative example, an HCDS gas was used as a raw material gas, a TEA gas was used as an amine-based gas and an O 2  gas is used as a reaction gas.  FIG. 8B  is a timing diagram of gas supply in a film forming sequence of this comparative example. As shown in  FIG. 8B , the internal pressure of a process chamber was set to 930 Pa for a HCDS gas supply process, 2 Pa for a residual HCDS gas exhaust process, 2660 Pa for a TEA gas supply process and 2 Pa for a residual TEA gas exhaust process. Other film forming conditions (process conditions in each Step) was set to fall within a range of the process conditions described in the above-described first embodiment. 
     The results of the film forming sequence of the example showed that the batch process of forming the SiOC films could be stably repeated without increasing a back pressure of a vacuum pump. The results of the film forming sequence of the comparative example showed that the batch process of forming the SiOC films increased a back pressure of a vacuum pump by one to several times, which caused the exhaust line to be blocked. When the exhaust line was dissembled, it was confirmed that considerable reaction byproducts were adhered to the downstream side of the vacuum pump of the exhaust line, in particular a portion between a trap device and a harm-removing device. 
     &lt;Additional Aspects of Present Disclosure&gt; 
     Hereinafter, some aspects of the present disclosure will be additionally stated. 
     A first aspect of the present disclosure may provide a method of manufacturing a semiconductor device, including: forming a film on a substrate by performing a cycle a predetermined number of times, the cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying an amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped, wherein a degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     In some embodiments, the act of exhausting the amine-based gas remaining in the process chamber includes: exhausting the amine-based gas remaining in the process chamber with the degree of valve opening as a first degree of valve opening; and exhausting the amine-based gas remaining in the process chamber with the degree of valve opening as a second degree of valve opening which is higher than the first degree of valve opening. 
     In some embodiments, the second degree of valve opening is fully-opened. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber includes continuously supplying an inert gas into the process chamber. 
     In some embodiments, the raw material gas contains a halogen element. 
     In some embodiments, the raw material gas contains a chlorine element or a fluorine element. 
     In some embodiments, the raw material gas contains a chlorine element. 
     In some embodiments, the amine-based gas contains amine. 
     In some embodiments, the amine-based gas contains at least one amine selected from a group consisting of ethylamine, methylamine, propylamine, isopropylamine, butylamine and isobutylamine. 
     In some embodiments, the amine-based gas contains at least one amine selected from a group consisting of triethylamine, diethylamine, monoethylamine, trimethylamine, dimethylamine, monomethylamine, tripropylamine, dipropylamine, monopropylamine, triisopropylamine, diisopropylamine, monoisopropylamine, tributylamine, dibutylamine, monobutylamine, triisobutylamine, diisobutylamine and monoisobutylamine. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber includes changing a set internal pressure of the process chamber in multiple steps. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber includes: exhausting the amine-based gas remaining in the process chamber with the set internal pressure of the process chamber as a first set internal pressure; and exhausting the amine-based gas remaining in the process chamber with the set internal pressure of the process chamber as a second set internal pressure which is lower than the first set internal pressure. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber with the set internal pressure of the process chamber as a second set internal pressure includes exhausting the amine-based gas with the maximum exhaust capability of the exhaust line. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber includes changing the exhaust capability of the exhaust line in multiple steps. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber includes: exhausting the amine-based gas remaining in the process chamber with the exhaust capability of the exhaust line as a first exhaust capability; and exhausting the amine-based gas remaining in the process chamber with the exhaust capability of the exhaust line as a second exhaust capability which is higher than the first exhaust capability. 
     In some embodiments, exhausting the amine-based gas remaining in the process chamber with the exhaust capability of the exhaust line as a second exhaust capability includes exhausting the amine-based gas with the maximum exhaust capability of the exhaust line. 
     Another aspect of the present disclosure may provide a method of processing a substrate, including: forming a film on the substrate by performing a cycle a predetermined number of times, the cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying an amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped, wherein a degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     Another aspect of the present disclosure may provide a substrate processing apparatus including: a process chamber configured to accommodate a substrate; a raw material gas supply system configured to supply a raw material gas to the substrate in the process chamber; an amine-based gas supply system configured to supply an amine-based gas to the substrate in the process chamber; an exhaust line configured to exhaust the interior of the process chamber; an exhaust valve disposed in the exhaust line; and a controller configured to control the raw material gas supply system, the amine-based gas supply system, the exhaust line and the exhaust valve such that a film is formed on the substrate by performing a cycle a predetermined number of times, the cycle including: supplying the raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying the amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped, wherein a degree of valve opening of the exhaust valve is changed in multiple steps when the amine-based gas remaining in the process chamber is exhausted. 
     Another aspect of the present disclosure may provide a program that causes a computer to perform a method of manufacturing a semiconductor device, the method including: forming a film on a substrate by performing a cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying the amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped, wherein a degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     Another aspect of the present disclosure may provide a non-transitory computer-readable recording medium storing a program that causes a computer to perform a method of manufacturing a semiconductor device, the method including: forming a film on a substrate by performing a cycle including: supplying a raw material gas to a substrate in a process chamber; exhausting the raw material gas remaining in the process chamber through an exhaust line in a state where the supply of the raw material gas is being stopped; supplying an amine-based gas to the substrate in the process chamber; and exhausting the amine-based gas remaining in the process chamber through the exhaust line in a state where the supply of the amine-based gas is being stopped, wherein a degree of valve opening of an exhaust valve disposed in the exhaust line is changed in multiple steps in the act of exhausting the amine-based gas remaining in the process chamber. 
     According to the present disclosure in some embodiments, it is possible to provide a semiconductor device manufacturing method, a substrate processing method, a substrate processing apparatus and a computer-readable recording medium storing instructions for executing such methods, which are capable of preventing byproducts from being deposited in an exhaust pipe when a film is formed. 
     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 disclosure. Indeed, the novel methods and apparatuses described herein may be embodied in a variety of other forms; furthermore, various omissions, combinations, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.