Substrate processing methods, semiconductor device manufacturing methods, substrate processing apparatus and processes

Abstract

This invention relates to a substrate processing method, a semiconductor device manufacturing method, a substrate processing apparatus, and a process. The objective of this invention is to provide a technique that improves the stepped coverage of a film formed on a substrate. The invention includes: (a1) a step of supplying a first modified gas to the substrate; (a2) a step of supplying the substrate with a first processing gas having a first element; (b1) a step of supplying the substrate with a second modified gas; and (b2) a step of supplying the substrate with a second processing gas having a second element, which is more easily adsorbed onto the opening side of the substrate than the first processing gas under the same conditions; and a step of performing (a1) and (a2) a first number of times, and performing (b1) and (b2) a second number of times to form a film containing the first element and the second element; (b1) is performed under the condition that the second modified gas is more easily adsorbed onto the surface of the substrate than the first modified gas under the same conditions.

Description

Substrate Processing Method, Method for Manufacturing a Semiconductor Device, Substrate Processing Apparatus, and Program The present invention relates to a substrate processing method, a method for manufacturing a semiconductor device, a substrate processing apparatus, and a program. As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate having a concave portion is performed (for example, refer to Patent Document 1). [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 2022-085236 (Problems to be Solved by the Invention) The present invention provides a technique capable of improving the step coverage of a film formed on a substrate. (Technical Means for Solving the Problems) According to one aspect of the present invention, the following technique is provided, which includes: (a1) a step of supplying a first modifying gas to a substrate; (a2) a step of supplying a first processing gas having a first element to the substrate; (b1) a step of supplying a second modifying gas to the substrate; and (b2) a step of supplying a second processing gas having a second element and being more likely to adsorb on the surface of the substrate than the first processing gas under the same conditions to the substrate; the above aspect also includes a step of performing (a1) and (a2) a first number of times and performing (b1) and (b2) a second number of times to form a film containing the first element and the second element; and (b1) is performed under a condition that the second modifying gas is more likely to adsorb on the surface of the substrate than the first modifying gas under the same conditions. (Effects Compared with the Prior Art) According to the present invention, the step coverage of a film formed on a substrate can be improved. <One Aspect of the Present Invention> Hereinafter, one aspect of the present invention will be mainly described with reference to FIGS. 1 to 4, FIGS. 6(a) to 6(f), and FIG. 7. Moreover, the drawings used in the following description are all schematic, and the dimensional relationships of the respective elements shown in the drawings, the ratios of the respective elements, etc. do not necessarily conform to the actual situation. Also, the dimensional relationships of the respective elements between a plurality of drawings, the ratios of the respective elements, etc. do not necessarily match. (1) Configuration of the Substrate Processing Apparatus As shown in FIG. 1, the processing furnace 202 of the substrate processing apparatus has a heater 207 as a heating mechanism (temperature adjustment unit). The heater 207 has a cylindrical shape and is vertically erected supported by a holding plate. The heater 207 also has a function as an activation mechanism (excitation unit) for activating (exciting) a gas by heat. Inside the heater 207, a reaction tube 203 is disposed concentrically with the heater 207. The reaction tube 203 is made of, for example, quartz (SiO 2) or a heat-resistant material such as silicon carbide (SiC), and is formed in a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) for example, and is formed in a cylindrical shape with open upper and lower ends. At the upper end portion of the manifold 209, it is engaged with the lower end portion of the reaction tube 203 to support the reaction tube 203. An O-ring 220a as a sealing member is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 is vertically installed in the same way as the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the cylindrical hollow portion of the processing container. The processing chamber 201 is configured to accommodate the wafer 200 as a substrate. The wafer 200 is processed in this processing chamber 201. In the processing chamber 201, nozzles 249a to 249c as the first to third supply parts are respectively provided to penetrate the side wall of the manifold 209. The nozzles 249a to 249c are also respectively referred to as the first to third nozzles. The nozzles 249a to 249c are made of a heat-resistant material such as quartz or SiC for example. Gas supply pipes 232a to 232c are respectively connected to the nozzles 249a to 249c. The nozzles 249a to 249c are respectively different nozzles, and the nozzles 249a and 249c are respectively adjacently arranged to the nozzle 249b. In the gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c belonging to a flow controller (flow control part) and valves 243a to 243c belonging to a switching valve are respectively provided in order from the upstream side of the gas flow. On the more downstream side of the valve 243a in the gas supply pipe 232a, gas supply pipes 232d and 232g are respectively connected. On the more downstream side of the valve 243b in the gas supply pipe 232b, gas supply pipes 232e and 232h are respectively connected. On the more downstream side of the valve 243c in the gas supply pipe 232c, gas supply pipes 232f and 232i are connected. On the gas supply pipes 232d to 232i, MFCs 241d to 241i and valves 243d to 243i are respectively provided in order from the upstream side of the air flow. The gas supply pipes 232a to 232i are made of a metal material such as SUS for example. As shown in FIG. 2, the nozzles 249a to 249c are respectively arranged to stand upright from the lower part to the upper part along the inner wall of the reaction tube 203 in a space that is annular in a plan view between the inner wall of the reaction tube 203 and the wafer 200, in the arrangement direction of the wafer 200 above. That is, the nozzles 249a to 249c are respectively arranged along the wafer arrangement area in a region that horizontally surrounds the wafer arrangement area on the side of the wafer arrangement area where the wafer 200 is arranged. The nozzle 249a is arranged on the side farther from the exhaust port 231a described later than the nozzles 249b and 249c. That is, the nozzles 249b and 249c are arranged on the side closer to the exhaust port 231a than the nozzle 249a. Also, the nozzles 249b and 249c are arranged line-symmetrically with the straight line passing through the center of the wafer 200 in the state of passing through the wafer 200 carried into the processing chamber 201, that is, passing through the center of the reaction tube 203 and the center of the exhaust port 231a as the axis of symmetry in a plan view. Also, the nozzles 249a and 249b are arranged to face each other on a straight line with the center of the reaction tube 203 held therebetween. The first reformed gas is supplied into the processing chamber 201 from the gas supply pipe 232a via the MFC241a, the valve 243a, and the nozzle 249a. The second reformed gas is supplied into the processing chamber 201 from the gas supply pipe 232b via the MFC241b, the valve 243b, and the nozzle 249b. The first reaction gas as the first processing gas is supplied into the processing chamber 201 from the gas supply pipe 232c via the MFC241c, the valve 243c, and the nozzle 249c. The first raw material gas as the first processing gas is supplied into the processing chamber 201 from the gas supply pipe 232d via the MFC241d, the valve 243d, the gas supply pipe 232b, and the nozzle 249b. The second raw material gas as the second processing gas is supplied into the processing chamber 201 from the gas supply pipe 232e via the MFC241e, the valve 243e, the gas supply pipe 232b, and the nozzle 249b. The second reaction gas as the second processing gas is supplied into the processing chamber 201 from the gas supply pipe 232f via the MFC241f, the valve 243f, the gas supply pipe 232c, and the nozzle 249c. Inert gas is supplied into the processing chamber 201 from the gas supply pipes 232g to 232i via the MFC241g to 241i, the valves 243g to 243i, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc. The first reforming gas supply section mainly consists of a gas supply pipe 232a, an MFC 241a, and a valve 243a. The second reforming gas supply section mainly consists of a gas supply pipe 232b, an MFC 241b, and a valve 243b. The first processing gas supply section (the first raw material gas supply section, the first reaction gas supply section) mainly consists of a gas supply pipe 232c, a gas supply pipe 232d, an MFC 241c, an MFC 241d, a valve 243c, and a valve 243d. The second processing gas supply section (the second raw material gas supply section, the second reaction gas supply section) mainly consists of a gas supply pipe 232e, a gas supply pipe 232f, an MFC 241e, an MFC 241f, a valve 243e, and a valve 243f. The inert gas supply section mainly consists of gas supply pipes 232g to 232i, MFCs 241g to 241i, and valves 243g to 243i. In any one or all of the above various supply systems, the supply systems may also be configured as an integrated gas supply system 248 formed by aggregating valves 243a to 243i, MFCs 241a to 241i, etc. The integrated gas supply system 248 is configured to be connected to each of the gas supply pipes 232a to 232i, and the supply of various substances (various gases) into the gas supply pipes 232a to 232i is controlled by a controller 121 described later, that is, the opening and closing operations of the valves 243a to 243i, the flow rate adjustment operations performed by the MFCs 241a to 241i, etc. The integrated gas supply system 248 is configured as an integrated or split-type integrated unit, which can be loaded and unloaded for the gas supply pipes 232a to 232i, etc. in units of the integrated unit, and is configured to perform maintenance, replacement, addition, etc. of the integrated gas supply system 248 in units of the integrated unit. Below the side wall of the reaction tube 203, an exhaust port 231a for exhausting the environment in the processing chamber 201 is provided. The exhaust port 231a is arranged along the side wall of the reaction tube 203 from the lower part to the upper part, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is connected to a vacuum pump 246 as a vacuum exhaust device via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201, and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 is configured to perform vacuum exhaust and stop vacuum exhaust in the processing chamber 201 by switching the valve in a state where the vacuum pump 246 is actuated. Further, in a state where the vacuum pump 246 is actuated, it adjusts the valve opening degree according to the pressure information detected by the pressure sensor 245, thereby adjusting the pressure in the processing chamber 201. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 can also be considered to be included in the exhaust system. Below the manifold 209, a sealing cover 219 serving as a furnace port cover for hermetically closing the lower end opening of the manifold 209 is provided. The sealing cover 219 is made of a metal material such as SUS and is formed in a disk shape. On the upper surface of the sealing cover 219, an O-ring 220b serving as a sealing member that abuts against the lower end of the manifold 209 is provided. Below the sealing cover 219, a rotation mechanism 267 for rotating a susceptor 217 described later is provided. The rotation shaft 255 of the rotation mechanism 267 penetrates the sealing cover 219 and is connected to the susceptor 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the susceptor 217. The sealing cover 219 is configured to be lifted and lowered in the vertical direction by a susceptor elevator 115 serving as a lifting mechanism provided outside the reaction tube 203. The susceptor elevator 115 is a transfer device (transfer mechanism) configured to lift and lower the sealing cover 219 to transfer (carry in and out) the wafer 200 in and out of the processing chamber 201. Below the manifold 209, a gate 219s serving as a furnace port cover is provided. The gate 219s can hermetically close the lower end opening of the manifold 209 in a state where the sealing cover 219 is lowered and the susceptor 217 is carried out of the processing chamber 201. The gate 219s is made of a metal material such as SUS and is formed in a disk shape. On the upper surface of the gate 219s, an O-ring 220c serving as a sealing member that abuts against the lower end of the manifold 209 is provided. The opening and closing operation (lifting operation, rotating operation, etc.) of the gate 219s is controlled by a gate switch mechanism 115s. The susceptor 217 as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers, in a horizontal posture and in a state where their centers are aligned with each other, and to support them in a multi-stage and neatly arranged manner in the vertical direction, that is, they are arranged at intervals. The susceptor 217 is made of a heat-resistant material such as quartz or SiC, for example. Below the susceptor 217, a heat insulating plate 218 made of a heat-resistant material such as quartz or SiC is supported in a multi-stage manner. Moreover, in this specification, the notation of a numerical range such as "25 to 200 pieces" means that the range includes the lower limit value and the upper limit value. Therefore, for example, "25 to 200 pieces" means "25 pieces or more and 200 pieces or less". The same applies to other numerical ranges. In the reaction tube 203, a temperature sensor 263 as a temperature detector is provided. According to the temperature information detected by the temperature sensor 263, the energization state of the heater 207 is adjusted, and the temperature in the processing chamber 201 can be made into a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203. As shown in FIG. 3, the control unit (control means), that is, the controller 121, is composed of a computer, and it includes a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a memory device 121c, and an I / O port 121d. The RAM 121b, the memory device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 composed of a touch panel or the like is connected to the controller 121, for example. Also, an external memory device 123 can be connected to the controller 121. The memory device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. A control program for controlling the operation of the substrate processing apparatus, or a process recipe (recipe) such as a program or conditions for the substrate processing described later is recorded and stored in a readable manner in the memory device 121c. The process recipe functions as a program, and it is combined in such a way that the controller 121 causes the processing device to execute each process in the substrate processing described later to obtain a predetermined result. Hereinafter, as a general term for the process recipe, the control program, etc., it is also simply referred to as a program. Also, the process recipe is simply referred to as a recipe. In this specification, when using the term "program", it means a case where only the recipe alone is included, a case where only the control program alone is included, or a case where both are included. The RAM 121b is configured as a memory area (working area) for temporarily storing programs or data read out by the CPU 121a. The I / O port 121d is connected to the above-mentioned MFCs 241a to 241i, valves 243a to 243i, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, susceptor elevator 115, gate switch mechanism 115s, etc. The CPU 121a is configured to read a control program from the memory device 121c and execute it, and read a recipe from the memory device 121c in accordance with the input of operation instructions from the input / output device 122, etc. The CPU 121a is configured to control the flow rate adjustment operation of various gases using the MFCs 241a to 241i, the opening and closing operations of the valves 243a to 243g, the opening and closing operation of the APC valve 244, and the pressure adjustment operation using the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the susceptor 217 by the rotation mechanism 267, the lifting operation of the susceptor 217 using the susceptor elevator 115, the opening and closing operation of the gate 219s using the gate switch mechanism 115s, etc. The controller 121 can be configured by installing the above-mentioned program recorded and stored in the external memory device 123 into the computer. The external memory device 123 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, magneto-optical disks such as MOs, USB memories, semiconductor memories such as SSDs, etc. The memory device 121c or the external memory device 123 is configured as a recording medium readable by the computer. Hereinafter, as a general term for these, it is simply referred to as a recording medium. In this specification, when using the term recording medium, it means the case of only including the memory device 121c alone, the case of only including the external memory device 123 alone, or the case of including both. Moreover, the program can be provided to the computer without using the external memory device 123, but by using communication means such as a network or a dedicated line. (2) Substrate processing step As one step of the manufacturing steps of the semiconductor device using the above-mentioned processing device, as an example of the processing timing for forming a film on the wafer 200, which is a substrate having recesses such as grooves formed on its surface, FIGS. 4 and 6(a) to 6(f) are mainly used for explanation. In the following explanation, the operations of each part constituting the substrate processing device are controlled by the controller 121. In the processing timing of this aspect, the following steps are included: (a1) a step of supplying a first reforming gas to the wafer 200; (a2) a step of supplying a first processing gas having a first element to the wafer 200; (b1) a step of supplying a second reforming gas to the wafer 200; and (b2) a step of supplying a second processing gas having a second element and being more likely to adsorb on the surface of the wafer 200 than the first processing gas under the same conditions to the wafer 200; and performing (a1) and (a2) for a first number (n 1 times, n 1 is an integer of 1 or more), performing (b1) and (b2) for a second number (n 2 times, n 2 is an integer of 1 or more), to form a film containing the first element and the second element; and (b1) is performed under the condition that the second reforming gas is more likely to adsorb on the surface of the wafer 200 than the first reforming gas under the same conditions. Moreover, in the following examples, the case where the first processing gas is a gas (film-forming gas) containing a first raw material gas and a first reaction gas, and the second processing gas is a gas (film-forming gas) containing a second raw material gas and a second reaction gas will be described. Here, the second raw material gas is a gas that is more likely to adsorb on the surface of the wafer 200 than the first raw material gas under the same conditions. Also, in the following examples, the following case will be described: as the first processing gas containing the first element, a first raw material gas containing the first element and a first reaction gas are supplied; as the second processing gas containing the second element, a second raw material gas containing the second element and a second reaction gas are supplied. Also, in the following examples, the following case will be described: the first reforming gas is a gas (film-forming inhibiting gas) that inhibits the reaction between the first processing gas (first raw material gas and / or first reaction gas) and the surface of the wafer 200, and the second reforming gas is a gas (film-forming inhibiting gas) that inhibits the reaction between the second processing gas (second raw material gas and / or second reaction gas) and the surface of the wafer 200. Moreover, hereinafter, as a representative example, the following case will be described: as shown in FIG. 4, in the film formation step, a cycle including a step A1 of supplying a first reforming gas to the wafer 200, a step A2 of supplying a first raw material gas as the first processing gas to the wafer 200, and a step A3 of supplying a first reaction gas as the first processing gas to the wafer 200 is performed for a first number (n 1 times, n 1a first film containing the first element is formed by repeating the step B1 of supplying the second reforming gas to the wafer 200 on which the first film is formed, the step B2 of supplying the second source gas as the second processing gas to the wafer 200 on which the first film is formed, and the step B3 of supplying the second reaction gas as the second processing gas to the wafer 200 on which the first film is formed, for a second number of times (n 2 times, n 2 is an integer of 1 or more), so that a second film containing the second element is formed on the first film, thereby forming a stacked film composed of the first film containing the first element and the second film containing the second element laminated. In this embodiment, the case where the stacked film is formed by performing the first film formation and the second film formation once each will be described. Here, the stacked film may be a film containing the first element and the second element. Further, the formation of the stacked film may also be the formation of a film containing the first element and the second element. In this specification, for convenience, the processing timing shown in FIG. 4 is also represented as follows. The same notation is also used in the description of other embodiments such as the following modified examples. (First reforming gas → First source gas → First reaction gas) × n 1 → (Second reforming gas → Second source gas → Second reaction gas) × n 2 In this specification, when the term "wafer" is used, it is intended to mean the wafer itself, and it is also intended to mean a laminate of the wafer and a predetermined layer or film formed on its surface. When the term "wafer surface" is used in this specification, it is intended to mean the surface of the wafer itself, and it is also intended to mean the surface of a predetermined layer formed on the wafer. When it is described in this specification that "a predetermined layer is formed on the wafer", it is intended to mean that the predetermined layer is directly formed on the surface of the wafer itself, and it is also intended to mean that the predetermined layer is formed on a layer formed on the wafer. When the term "substrate" is used in this specification, it has the same meaning as when the term "wafer" is used. The term "layer" used in this specification includes at least any one of a continuous layer and a discontinuous layer. The layer formed in each step described later may include a continuous layer, may include a discontinuous layer, or may include both of these. (Wafer Filling and Cassette Loading) When loading a plurality of wafers 200 into a cassette 217 (wafer filling), the gate 219s is moved by the gate opening / closing mechanism 115s to open the lower end opening of the manifold 209 (gate opening). Then, as shown in FIG. 1, the cassette 217 supporting a plurality of wafers 200 is lifted by the cassette elevator 115 and carried into the processing chamber 201 (cassette loading). In this state, the sealing lid 219 seals the lower end of the manifold 209 via the O-ring 220b. Thus, the wafers 200 are prepared in the processing chamber 201. (Pressure Adjustment and Temperature Adjustment) After the cassette loading is completed, vacuum exhaust (pressure reduction exhaust) is performed by the vacuum pump 246 so that the pressure (vacuum level) in the processing chamber 201, i.e., the space where the wafers 200 are present, becomes the required pressure. At this time, the pressure in the processing 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). Also, the wafers 200 in the processing chamber 201 are heated by the heater 207 so that the wafers 200 reach the required processing temperature. At this time, the energization level of the heater 207 is feedback-controlled according to the temperature information detected by the temperature sensor 263 so that the required temperature distribution is achieved in the processing chamber 201 (temperature adjustment). Also, the rotation of the wafers 200 is started by the rotation mechanism 267. Exhaust in the processing chamber 201, heating of the wafers 200, and rotation of the wafers 200 are each continued at least until the processing of the wafers 200 is completed. <Stacked Film Formation> (First Film Formation) In the first film formation, the following steps A1, A2, and A3 are performed. [Step A1] In step A1, a first reforming gas is supplied to the wafers 200 in the processing chamber 201. Specifically, the valve 243a is opened to allow the first reforming gas to flow through the gas supply pipe 232a. The first reforming gas is flow-adjusted by the MFC241a, supplied to the processing chamber 201 via the nozzle 249a, and exhausted from the exhaust port 231a. At this time, the first reforming gas is supplied to the wafers 200 (first reforming gas supply). At this time, the valves 243g to 243i may also be opened to supply an inert gas to the processing chamber 201 via each of the nozzles 249a to 249c. By supplying the first modifying gas to the wafer 200 under the processing conditions described below, the first modifying gas is adsorbed on the surface of the wafer 200, and at least a part of the surface of the wafer 200 can be modified. Further, by supplying the first modifying gas to the wafer 200 under the processing conditions described below, the first modifying gas is less likely to be adsorbed on the surface of the wafer 200 than the second modifying gas under the same conditions. Further, by supplying the first modifying gas to the wafer 200 under the processing conditions described below, the amount of the first modifying gas adsorbed on the deep side 302 of the concave portion 300 is less than the amount of the first modifying gas adsorbed on the opening side 301 (see FIG. 6(a)). The first modifying gas prevents the adsorption of the first source gas and / or the first reaction gas on the surface of the wafer 200 in the steps A2 and A3 described below, and hinders (inhibits) the film formation reaction on the surface of the wafer 200. In addition, in this specification, the so-called "deep side 302 of the concave portion 300" refers to, for example, the bottom of the concave portion 300, etc., that is, a region where the gas supplied to the wafer 200 is difficult to reach and its periphery compared with the opening side 301 of the concave portion 300. As the processing conditions for supplying the first modifying gas in step A1, the following can be exemplified: Processing temperature: 300 to 850 °C, preferably 600 to 750 °C; Processing pressure: 1 to 5000 Pa; First modifying gas supply flow rate: 0.05 to 10.0 slm; First modifying gas supply time: 5 to 300 seconds; Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm. In this specification, the so-called processing temperature means the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure means the pressure in the processing chamber 201. Further, the so-called gas supply flow rate: 0 slm means the case where the gas is not supplied. The same applies to the following description. As the first modifying gas, for example, a gas containing a halogen can be used. The halogen includes at least any one of chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). As the first modifying gas, for example, fluorine (F 2 ) gas, chlorine (Cl 2 ) gas, bromine (Br 2 ) gas, iodine (I 2 ) gas, nitrogen fluoride (NF 3 ) gas, chlorine fluoride (ClF 3 ) gas, hydrogen fluoride (HF) gas, hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, hydrogen iodide (HI) gas, etc. As the first modifying gas, one or more of these can be used. Further, as the first modifying gas, for example, a halosilane gas containing silicon (Si) and a halogen can be used. As the halosilane gas, for example, a chlorosilane gas containing Si and Cl can be used. For example, it includes dichlorosilane (SiH 2 Cl 2 ) gas, trichlorosilane (SiHCl 3 ) gas, tetrachlorosilane (SiCl 4 ), pentachlorodisilane (Si 2 H 1 Cl 5 ), hexachlorodisilane (Si 2 Cl 6 ) gas. As the first modifying gas, one or more of these can be used. Further, as the first modifying gas, a gas containing an organic compound can be used. As the gas containing an organic compound, a gas containing at least any one selected from the group consisting of an ether compound, a ketone compound, an amine compound, and an organic hydrazine compound can be used. As the gas containing an ether compound, a gas containing at least any one of dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, tetrahydropyran, etc. can be used. As the gas containing a ketone compound, a gas containing at least any one of dimethyl ketone, diethyl ketone, methyl ethyl ketone, methyl propyl ketone, etc. can be used. As the gas containing an amine compound, a gas containing at least any one of methylamine compounds such as monomethylamine, dimethylamine, trimethylamine, ethylamine compounds such as monoethylamine, diethylamine, triethylamine, and methylethylamine compounds such as dimethylethylamine, methyldiethylamine can be used. As the gas containing an organic hydrazine compound, a gas containing at least any one of methylhydrazine-based gases such as monomethylhydrazine, dimethylhydrazine, trimethylhydrazine can be used. As the first modifying gas, one or more of these can be used. As the inert gas, nitrogen (N 2 ) gas, or a noble gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. As the inert gas, one or more of these can be used. This is the same in each of the steps described later. After the first reforming gas is adsorbed on the surface of the wafer 200 (the surface inside the recess 300), the valve 243a is closed to stop the supply of the first reforming gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gaseous substances and the like remaining in the processing chamber 201 from the processing chamber 201. At this time, the valves 243g to 243i are opened, and an inert gas is supplied into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, whereby the space where the wafer 200 is located, that is, the inside of the processing chamber 201, is purged (cleaned). [Step A2] After the end of Step A1, a first source gas containing a first element is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 whose surface in the recess 300 has adsorbed the first reforming gas. Specifically, the valve 243d is opened to allow the first source gas to flow through the gas supply pipe 232d. The flow rate of the first source gas is adjusted by the MFC241d, supplied into the processing chamber 201 through the gas supply pipe 232a and the nozzle 249a, and exhausted through the exhaust port 231a. At this time, the first source gas is supplied to the wafer 200 (the first source gas supply). At this time, the valves 243g to 243i may also be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c respectively. By supplying the first source gas containing the first element to the wafer 200 under the processing conditions described below, the first source gas can be adsorbed on the positions on the surface of the wafer 200 (the surface inside the recess 300) where the first reforming gas has not been adsorbed (see FIG. 6(b)). Specifically, the positions on the surface inside the recess 300 where the first reforming gas has been adsorbed will hinder the adsorption of the first source gas, and the first source gas (the first element) will preferentially adsorb on the positions where the first reforming gas has not been adsorbed, and a first element-containing layer is formed at these positions (regions). As the processing conditions for supplying the first source gas in Step A2, examples include: processing pressure: 1 to 10000 Pa; first source gas supply flow rate: 0.05 to 3 slm, preferably 0.1 to 2 slm; first source gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds; other processing conditions are the same as those for supplying the first reforming gas in Step A1. After a first element-containing layer is formed on the surface of the wafer 200 (the surface inside the recess 300), the valve 243d is closed to stop the supply of the first source gas into the processing chamber 201. Then, using the same processing steps and processing conditions as the purge in Step A1, the gaseous substances and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (purged). [Step A3] After the end of Step A2, a first reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 having the surface of the concave portion 300 on which the first element layer has been formed. Specifically, the valve 243c is opened to allow the first reaction gas to flow through the gas supply pipe 232c. The flow rate of the first reaction gas is adjusted by the MFC241c, supplied into the processing chamber 201 via the nozzle 249c, and exhausted from the exhaust port 231a. At this time, the first reaction gas is supplied to the wafer 200 (first reaction gas supply). At this time, the valves 243g to 243i may also be opened to supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively. By supplying the first reaction gas to the wafer 200 having the first element layer formed thereon under the processing conditions described below, at least a part of the first element layer can react with the first reaction gas to modify the first element layer to form a first modified layer. As the processing conditions for supplying the first reaction gas in Step A3, the following can be exemplified: processing pressure: 1 to 10,000 Pa; first reaction gas supply flow rate: 1 to 30 slm, preferably 2 to 20 slm; first reaction gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds; other processing conditions are the same as those for supplying the first modification gas in Step A1. As the first reaction gas, for example, oxygen (O 2 ) gas, ozone (O 3 ) gas, hydrogen (H 2 ) gas + oxygen (O 2 ) gas, oxygen radical (O 2 *) and other oxygen-containing gases can be used. Moreover, in this specification, the juxtaposed description of "H 2 gas + O 2 gas" means a mixed gas of H 2 gas and O 2 gas. In the case of supplying the mixed gas, the two gases can be mixed in the supply pipe (pre-mixed) and then supplied into the processing chamber 201, or the two gases can be supplied into the processing chamber 201 from different supply pipes and mixed in the processing chamber 201 (post-mixed). As the first reaction gas, one or more of these can be used. After changing the first element layer formed inside the recess 300 into the first modified layer, the valve 243c is closed to stop the supply of the first reaction gas into the processing chamber 201. Then, by the same processing steps and processing conditions as the rinsing in step A1, the gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201 (rinsing). [Execute a fixed number of times] By performing the cycles of steps A1, A2, and A3 asynchronously, that is, out of sync, in sequence n 1 times (n 1 is an integer of 1 or more), a first film can be further formed on the surface of the wafer 200 (refer to FIG. 6(c)). As the first source gas, for example, an Al-containing gas with aluminum (Al) as the first element is used; as the first reaction gas, for example, an oxygen (O)-containing gas can be used. In this case, an aluminum oxide film (AlO film) is formed as the first film on the surface of the wafer 200. The above cycle is preferably repeated a plurality of times. That is, preferably, the thickness of the first modified layer formed in each cycle is made thinner than the desired film thickness, and the above cycle is repeated a plurality of times until the film thickness of the first film formed by laminating the first modified layers becomes the desired film thickness. (Second film formation) In the second film formation, the following steps B1, B2, and B3 are performed. [Step B1] In step B1, a second modifying gas is supplied to the wafer 200 on which the first film has been formed. Specifically, the valve 243b is opened to allow the second modifying gas to flow through the gas supply pipe 232b. The second modifying gas is adjusted in flow rate by the MFC241b, supplied into the processing chamber 201 through the nozzle 249b, and exhausted from the exhaust port 231a. At this time, the second modifying gas is supplied to the wafer 200 (second modifying gas supply). At this time, the valves 243g to 243i can also be opened to supply an inert gas into the processing chamber 201 through each of the nozzles 249a to 249c. By supplying the second modifying gas to the wafer 200 under the processing conditions described below, the second modifying gas is adsorbed on the surface of the first film, and at least a part of the surface of the first film can be modified. Further, by supplying the first modifying gas to the wafer 200 under the processing conditions described below, the second modifying gas can be more easily adsorbed on the surface of the wafer 200 than the first modifying gas under the same conditions. Further, by supplying the second modifying gas to the wafer 200 under the processing conditions described below, the amount of the second modifying gas adsorbed on the deep side 302 of the concave portion 300 can be made less than the amount adsorbed on the opening side 301 (see FIG. 6(d)). The second modifying gas prevents the adsorption of the second source gas and the second reaction gas on the surface of the first film in the steps B2 and B3 described below, and hinders (inhibits) the film formation reaction on the surface of the first film. As the processing conditions for supplying the second modifying gas in step B1, examples include: processing pressure: 1 to 1000 Pa; second modifying gas supply flow rate: 0.01 to 1 slm; second modifying gas supply time: 2 to 250 seconds. At this time, for the reasons described below, it is preferably set in such a manner that the conditions of step A1 and step B1 are set under the condition that the second modifying gas is more easily adsorbed on the surface of the wafer 200 than the first modifying gas under the same conditions. For example, it is preferable that the pressure (processing pressure) in the space where the wafer 200 exists in step B1 is less than the processing pressure in step A1. Further, for example, it is preferable that the time for supplying the second modifying gas to the wafer 200 in step B1 is shorter than the time for supplying the first modifying gas to the wafer 200 in step A1. Further, for example, it is preferable that the partial pressure of the second modifying gas in the space (in the processing chamber 201) where the wafer 200 exists in step B1 is less than the partial pressure of the first modifying gas in the processing chamber 201 in step A1. As the second modifying gas, a predetermined gas can be arbitrarily selected from the first modifying gases exemplified in step A1 and used. Moreover, the second modifying gas used in step B1 and the first modifying gas used in step A1 can be the same gas (gas having the same molecular structure) or different gases (gases having different molecular structures). When the first modifying gas and the second modifying gas are the same gas, the configuration of the gas supply system can be simplified. In the case where a gas different from the first reforming gas is used as the second reforming gas, the types of the first reforming gas and the second reforming gas can be selected in such a manner that the adsorbability of the second reforming gas to the surface of the wafer 200 is higher than that of the first reforming gas. Thereby, since it can be carried out under the condition that the second reforming gas is more likely to be adsorbed on the surface of the wafer 200 than the first reforming gas under the same conditions, it is preferable for the reasons described later. For example, it is preferable to use a second reforming gas having a molecular weight larger than that of the first reforming gas. Also, for example, it is preferable to use a second reforming gas having a molecular radius larger than that of the first reforming gas. Also, for example, it is preferable to use a second reforming gas having a higher reactivity with respect to the surface of the wafer 200 than the first reforming gas under the same conditions. Also, for example, it is preferable that: as the second source gas, a gas that chemically reacts with the adsorption sites on the surface of the wafer 200 is used, and as the first source gas, a gas that physically adsorbs on the adsorption sites on the surface of the wafer 200 is used. Thereby, it is easy to make the amount of the second reforming gas adsorbed on the deep side 302 of the recess 300 less than the amount of the first reforming gas adsorbed on the deep side 302 of the recess 300 in step A1. Herein, the "adsorbability to the surface of the wafer 200" of the gas refers to the ease of adsorption of the gas to the opening side 301 of the wafer 200. Also, for example, in the case where an organic gas or an inorganic gas is used as the first source gas or the second source gas, an organic gas or an inorganic gas can be used as the first reforming gas or the second reforming gas accordingly. After the second reforming gas is adsorbed, the valve 243b is closed to stop the supply of the second reforming gas into the processing chamber 201. Then, the gaseous substances remaining in the processing chamber 201 are exhausted from the processing chamber 201 (flushed) by the same processing steps and processing conditions as the flushing in step A1. [Step B2] After step B1 is completed, a second source gas containing a second element is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 on the surface of which the second reforming gas has been adsorbed in the recess 300. Specifically, the valve 243e is opened to allow the second source gas to flow in the gas supply pipe 232e. The second source gas is adjusted in flow rate by the MFC241e, supplied into the processing chamber 201 via the gas supply pipe 232b and the nozzle 249b, and exhausted from the exhaust port 231a. At this time, the second source gas is supplied to the wafer 200 (second source gas supply). At this time, the valves 243g to 243i can also be opened to supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively. By supplying a second source gas containing a second element to the wafer 200 under the processing conditions described below, the second source gas can be adsorbed on the surface of the wafer 200 (the surface of the first film in the concave portion 300) at a position where the second modifying gas is not adsorbed (see FIG. 6(e)). Specifically, the position on the surface of the first film in the concave portion 300 where the second modifying gas has been adsorbed will hinder the adsorption of the second source gas, and the second source gas (the second element) will preferentially adsorb at the position where the second modifying gas is not adsorbed, and a second element-containing layer will be formed at this position (region). As the processing conditions for supplying the second source gas in step B2, the following can be exemplified: processing pressure: 1 to 10,000 Pa; second source gas supply flow rate: 0.05 to 3 slm, preferably 0.1 to 2 slm; second source gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds; other processing conditions are the same as those for supplying the first modifying gas in step A1. Moreover, the first element contained in the first source gas and the second element contained in the second source gas can be the same element or different elements. After forming the second element-containing layer on the first film, the valve 243e is closed to stop the supply of the second reaction gas into the processing chamber 201. Then, the gaseous substances remaining in the processing chamber 201 are removed (flushed) from the processing chamber 201 by the same processing steps and processing conditions as the flushing in step A1. [Step B3] After the end of step B2, a second reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 in the concave portion 300 on the surface of which the second element-containing layer has been formed. Specifically, the valve 243f is opened to allow the second reaction gas to flow in the gas supply pipe 232f. The second reaction gas is adjusted in flow rate by the MFC241d, supplied into the processing chamber 201 through the gas supply pipe 232c and the nozzle 249c, and exhausted from the exhaust port 231a. At this time, the second reaction gas is supplied to the wafer 200 (second reaction gas supply). At this time, the valves 243g to 243i can also be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c respectively. By supplying the second reaction gas to the wafer 200 on which the second element-containing layer has been formed under the processing conditions described below, at least a part of the second element-containing layer can react with the second reaction gas to modify the second element-containing layer to form a second modified layer. As the processing conditions for supplying the second reaction gas in step B3, the following can be exemplified: processing pressure: 1 to 10,000 Pa; second reaction gas supply flow rate: 1 to 30 slm, preferably 2 to 20 slm; second reaction gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds; other processing conditions are the same as those for supplying the first reforming gas in step A1. As the second reaction gas, a predetermined gas can be arbitrarily selected from the first reaction gases exemplified in step A2 and used. Moreover, the second reaction gas used in step B3 and the first reaction gas used in step A3 may have the same molecular structure or different molecular structures. [Perform a predetermined number of times] By performing the cycles of steps B1, B2, and B3 asynchronously, that is, out of sync, in sequence n 2 times (n 2 is an integer of 1 or more), a second film can be formed on the surface of the wafer 200 (refer to FIG. 6(f)). As the second source gas, for example, a Hf-containing gas containing hafnium (Hf) as the second element is used; as the second reaction gas, for example, an oxygen (O)-containing gas can be used. In this case, a hafnium oxide film (HfO film) is formed as the second film on the surface of the wafer 200. The above cycle is preferably repeated a plurality of times. That is, it is preferable that the thickness of the second reformed layer formed in each cycle is thinner than the desired film thickness, and the above cycle is repeated a plurality of times until the film thickness of the second film formed by laminating the second reformed layers becomes the desired film thickness. By performing the cycle of steps A1, A2, and A3 in sequence n 1 times (the first number of times) to form the first film, and performing the cycle of steps B1, B2, and B3 in sequence n2 times (the second number of times) to form the second film, a laminated film in which the first film and the second film are laminated in the above order can be formed on the surface of the wafer 200. (Post-rinse and atmospheric pressure recovery) After the formation of the laminated film is completed, an inert gas as a rinse gas is supplied into the processing chamber 201 from each of the nozzles 249a to 249c, and exhausted from the exhaust port 231a. Thereby, the inside of the processing chamber 201 is rinsed, and gases or reaction by-products remaining in the processing chamber 201 are removed from the inside of the processing chamber 201 (post-rinse). Thereafter, the environment inside the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is restored to normal pressure (atmospheric pressure recovery). (Wafer unloading and wafer taking out) Then, the sealing cover 219 is lowered by the wafer elevator 115 to open the lower end of the manifold 209. Then, the processed wafer 200 is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 in the state of being supported by the wafer boat 217 (wafer unloading). After the wafer unloading, the gate 219s is moved to seal the lower end opening of the manifold 209 via the O-ring 220c by the gate 219s (gate closing). After the processed wafer 200 is carried out to the outside of the reaction tube 203, it is taken out from the wafer boat 217 (wafer taking out). (3) Effects brought by this aspect According to this aspect, in addition to the above effects, one or more of the following effects can be obtained. (a) In step B1, the condition is such that the second reforming gas is more likely to be adsorbed on the surface of the wafer 200 than the first reforming gas under the same conditions. At this time, the amount of the second reforming gas adsorbed on the deep side 302 of the recess 300 is less than the amount of the first reforming gas adsorbed on the deep side 302 of the recess 300 in step A1. Thereby, the step coverage of the laminated film formed by laminating the first film and the second film can be improved. Also, in step B2, by making the second source gas easily adsorbed on the deep side 302 of the recess 300, the film formation rate can be increased. Hereinafter, these will be described. As described above, in step B2, the second source gas that is more likely to be adsorbed on the opening side 301 than the first source gas under the same conditions is supplied to the wafer 200. Also, the gas supplied to the wafer 200 having the recess 300 tends to easily reach (be adsorbed on) the opening side 301 and is difficult to reach (be adsorbed on) the deep side 302. Therefore, compared with the first source gas supplied under the same conditions, the adsorption amount of the second source gas on the opening side 301 is likely to increase, and the adsorption amount on the deep side 302 is likely to decrease. Therefore, for example, when the first reforming gas and the second reforming gas are adsorbed on the deep side 302 to the same extent, the thickness of the second film at the deep side 302 is likely to be smaller than that of the first film. Therefore, compared with the first film, the step coverage of the second film is more likely to decrease. Therefore, the amount of the second reforming gas adsorbed on the deep side 302 is preferably less than the amount of the first reforming gas adsorbed on the deep side 302. Also, if the step coverage of the second film decreases, the step coverage of the laminated film formed by the first film and the second film also decreases. In this aspect, in step B1, the condition is such that the second modified gas is more likely to be adsorbed on the surface of the wafer 200 than the first modified gas under the same conditions. Thereby, the amount of the second modified gas adsorbed on the deep part side 302 in step B1 can be made less than the amount of the first modified gas adsorbed on the deep part side 302 in step A1. That is, the second modified gas is preferentially adsorbed on the opening side 301 (see FIGS. 6(a) and 6(d)). Thereby, the adsorption of the second source gas at the opening side 301 can be easily hindered, and the adsorption of the second source gas at the deep part side 302 is difficult to be hindered. Thereby, the difference in the adsorption amount of the second source gas between the opening side 301 and the deep part side 302 of the recess 300 can be reduced, and thus a second film with excellent step coverage can be formed (see FIG. 6(f)). Moreover, since the step coverage of the second film is improved, the step coverage of the stacked film can be improved. Also, regarding the deep part side 302 of the recess 300, compared with the opening side 301, it is difficult for the processing gas (source gas, reaction gas) to reach the deep part side 302. Therefore, the adsorption amount of the processing gas in the deep part side 302 is less than that in the opening side 301. Therefore, if the second modified gas is adsorbed on the deep part side 302, it will cause a delay in the overall formation of the second film. In this aspect, as described above, the second modified gas is preferentially adsorbed on the opening side 301. In other words, the adsorption amount of the second modified gas at the deep part side 302 is reduced. Therefore, even if a gas that hinders the adsorption of the processing gas is used, a decrease in the film formation rate of the second film in the deep part side 302 can be suppressed. Furthermore, this is related to the suppression of the decrease in the film formation rate of the second film and the stacked film. However, the supply condition of the second modified gas in step B1 is preferably set in such a way that it does not have an adverse effect on the step coverage of the second film due to excessive adsorption of the second modified gas on the opening side 301. (b) By making the amount of the first modified gas adsorbed on the deep part side 302 of the recess 300 less than the amount of the first modified gas adsorbed on the opening side 301 (see FIG. 6(a)), the adsorption of the first source gas at the opening side 301 can be easily hindered, and the adsorption of the first source gas at the deep part side 302 is difficult to be hindered. Thereby, the difference in the adsorption amount of the first source gas between the opening side 301 and the deep part side 302 of the recess 300 can be reduced, and thus a first film and a stacked film with excellent step coverage can be formed (see FIG. 6(c)). (c) The pressure (processing pressure) in the space where the wafer 200 exists in step B1 can be made less than the processing pressure in step A1. Thereby, the amount of the second modified gas adsorbed on the deep part side 302 of the recess 300 in step B1 can be made less than the amount of the first modified gas adsorbed on the deep part side 302 of the recess 300 in step A1. Therefore, the step coverage and the film formation rate of the second film and the stacked film can be improved. (d) The time for supplying the second modifying gas to the wafer 200 in step B1 can be made shorter than the time for supplying the first modifying gas to the wafer 200 in step A1. Thereby, the amount of the second modifying gas adsorbed on the deep side 302 of the recess 300 in step B1 can be made less than the amount of the first modifying gas adsorbed on the deep side 302 of the recess 300 in step A1. Therefore, the step coverage and the film formation rate of the second film and the stacked film can be improved. (e) The partial pressure of the second modifying gas in the space (inside the processing chamber 201) where the wafer 200 is located in step B1 can be made smaller than the partial pressure of the first modifying gas in the processing chamber 201 in step A1. Thereby, the amount of the second modifying gas adsorbed on the deep side 302 of the recess 300 in step B1 can be made less than the amount of the first modifying gas adsorbed on the deep side 302 of the recess 300 in step A1. Therefore, the step coverage and the film formation rate of the second film and the stacked film can be improved. (f) By using a second modifying gas having a higher adsorption property to the opening side 301 of the wafer 200 than the first modifying gas, the step coverage and the film formation rate of the second film and the stacked film can be further improved. (g) By making at least one of the first source gas and the second source gas a gas not having an organic ligand, the amount of carbon (C) absorbed as an impurity into the stacked film can be reduced. Thereby, the etching resistance and the electrical characteristics of the first film and / or the second film and the stacked film can be improved. (h) When arbitrarily selecting and using a predetermined substance from the above various modifying gases, various source gases, various reaction gases, and various inert gases, the above effects can be obtained in the same manner. <Other aspects of the present invention> Above, various aspects of the present invention have been specifically described. However, the present invention is not limited to the above aspects, and various modifications can be made without departing from the gist thereof. For example, in the above aspect, the case of forming the second film after forming the first film and forming a stacked film has been described. That is, the case of performing the cycle of sequentially performing steps A1, A2, and A3 n 1 times, and then performing the cycle of sequentially performing steps B1, B2, and B3 n 2 times to form a film containing the first element and the second element has been described. However, the present invention is not limited to these aspects. For example, the first film may also be formed after forming the second film to form a stacked film. That is, the cycle of sequentially performing steps B1, B2, and B3 may also be performed n 2 times, and then the cycle of sequentially performing steps A1, A2, and A3 may be performed n 1Next, a film containing the first element and the second element is formed. In such cases, the same effects as those in the above aspects are also obtained. For example, in the above aspect, the case of forming a laminated film composed of a first film containing the first element and a second film containing the second element has been described. However, the present invention is not limited to such aspects. For example, one of the first gas having the first element and the second gas having the second element that is difficult to adsorb on the surface of the wafer 200 may be used as the first processing gas, and the other may be used as the second processing gas to form a film containing the first element and the second element (a film mainly composed of the first element and the second element). For example, titanium tetrachloride (TiCl 4 ) gas having titanium (Ti) as a metal element and ammonia (NH 3 ) gas having nitrogen (N), and NH 3 gas that is difficult to adsorb on the surface of the wafer 200 may be used as the first processing gas (reaction gas), and TiCl 4 gas may be used as the second processing gas (source gas). In this case, the first element is N, the second element is Ti, and as a film containing the first element and the second element, a titanium nitride film (TiN film) is formed. That is, one of the first processing gas and the second processing gas may be a source gas and the other may be a reaction gas. In this case, as the source gas, gases exemplified as the first source gas and the second source gas as described later can be used. Also, as the reaction gas, gases exemplified as the first reaction gas and the second reaction gas as described later can be used. In this case, the same effects as those in the above aspects are also obtained. For example, in the above aspect, the case of forming a laminated film by performing the first film formation and the second film formation once each has been described. However, the present invention is not limited to such aspects. For example, the first film formation and the second film formation may be alternately performed multiple times to form a stacked film. In this case, the same effects as those in the above aspects are also obtained. Here, the stacked film formed by laminating the first film containing the first element and the second film containing the second element may be a film containing the first element and the second element. For example, in the above aspect, the case where both the first reaction gas and the second reaction gas are O-containing gases has been described as an example. However, the present invention is not limited to such aspects. For example, the first reaction gas and the second reaction gas may not only be O-containing gases, but also N-containing gases, C-containing gases such as organic gases, for example, H 2 gases such as hydrogen (H) gases, and also gases obtained by mixing these. As the N-containing gas, for example, ammonia (NH 3 ) gas, hydrazine (N 2 H 4 ) gas, diazene (N 2 H 2 ) gas, N 3 H 8 Gases such as nitrogen-containing gases containing N-H bonds (gases containing N and H), N 2 gas. By supplying these gases to the wafer 200, for example, as the first film and / or the second film, a stacked film, a metal film, a metal nitride film, a metal carbide film, a metal oxynitride film, a metal oxycarbide film, a metal carbonitride film, or a metal oxcarbonitride film can be formed. In these cases, the same effects as those in the above aspects are also obtained. When the first element and the second element are Si, for example, as the first source gas and the second source gas, a gas containing a halogen and Si, that is, a halogenosilane gas, can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As the halogenosilane gas, for example, the above-mentioned chlorosilane gas containing Cl and Si can be used. As the first source gas and / or the second source gas, for example, a gas containing metal elements such as titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), aluminum (Al), molybdenum (Mo), tungsten (W), silicon (Si), germanium (Ge), etc. as the first element and / or the second element can be used. As the gas containing metal elements, for example, trimethylaluminum (Al(CH 3 ) 3 ) gas These are gases containing a metal element and a ligand molecule bonded thereto. As the ligand, for example, an organic ligand can be mentioned, and preferably a hydrocarbon group containing at least any one selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, and butyl, cyclopentadienyl, cyclohexadienyl, and cycloheptatrienyl can be mentioned. Here, as the first source gas and / or the second source gas containing Zr, for example, a gas containing zirconium bis(ethylmethylamido) (Zr[N(CH 3 )C 2 H 5 4 ) Zirconium tetrakis(diethylamino) (Zr[N(C 2 H 5 ) 2 4 ) Zirconium tetrakis(dimethylamino) (Zr[N(CH 3 ) 2 4 ) Zr(MMP) 4 ) Zr(O-tBu) 4 ) Tris(dimethylamino)cyclopentadienylzirconium ((C 5 H 5 )Zr[N(CH 3 ) 2 3 ) A gas of at least any one of the group consisting of. As the first source gas and / or the second source gas, one or more of these can be used. Further, regarding a gas containing Hf as the first element and / or the second element, for example, a gas containing hafnium tetrakis(ethylmethylamino) (Hf[N(CH 3 )C 2 H 5 4 ) hafnium tetrakis(diethylamino) (Hf[N(C 2 H 5 ) 2 4 ) hafnium tetrakis(dimethylamino) (Hf[N(CH 3 ) 2 4 ) Hf(O-tBu) 4, Hf(MMP) 4 , bis(dimethylamino)cyclopentadienyl hafnium ((C 5 H 5 )Hf[N(CH 3 ) 2 3 ) or any gas in the group consisting of. As the first source gas and / or the second source gas, one or more of these can be used.. Furthermore, regarding the gas containing Ti as the first element and / or the second element, for example, a gas containing a compound selected from the group consisting of tetra(ethylmethylamino)titanium (Ti[N(CH 3 )C 2 H 5 4 ), tetra(diethylamino)titanium (Ti[N(C 2 H 5 ) 2 4 ), tetra(dimethylamino)titanium (Ti[N(CH 3 ) 2 4 ), Ti(O-tBu) 4 , Ti(MMP) 4 , bis(dimethylamino)cyclopentadienyl titanium ((C 5 H 5 )Ti[N(CH 3 ) 2 3 ) or any gas in the group consisting of. As the first source gas and / or the second source gas, one or more of these can be used. Further, as the first source gas and / or the second source gas, for example, an inorganic metal source gas containing a metal element and a halogen may also be used. For example, titanium tetrachloride (TiCl 4 ) gas, titanium tetrafluoride (TiF 4 ) gas, zirconium tetrachloride (ZrCl 4 ) gas, zirconium tetrafluoride (ZrF 4 ) gas, hafnium tetrachloride (HfCl 4 ) gas, hafnium tetrafluoride (HfF 4 ) gas, tantalum pentachloride (TaCl 5 ) gas, tantalum pentafluoride (TaF 5 ) gas, niobium pentachloride (NbCl 5 ) gas, niobium pentafluoride (NbF 5 ) gas, aluminum trichloride (AlCl 3 ) gas, aluminum trifluoride (AlF 3 ) gas, molybdenum pentachloride (MoCl 5 ) gas, molybdenum pentafluoride (MoF 5 ) gas, tungsten hexachloride (WCl 6 ) gas, tungsten hexafluoride (WF 6 ) gas, etc., inorganic metal source gases containing a metal element and a halogen. As the first source gas and / or the second source gas, one or more of these can be used. Further, regarding a gas containing Si as the first element and / or the second element, for example, silane (SiH 4 ) gas, disilane (Si 2 H 6 ) gas, trisilane (Si 3 H 8)Silane-based gases such as gases. Also, the above-mentioned halosilane gases can be used. As the first source gas and / or the second source gas, one or more of these can be used. As described above, the second source gas (second processing gas) is a gas that is more likely to adsorb on the surface of the wafer 200 than the first source gas (first processing gas) under the same conditions. Such a relationship is likely to hold, for example, when a gas that is more reactive with the surface of the wafer 200 than the first source gas under the same conditions is used as the second source gas. Also, for example, it is likely to hold when a gas having a functional group that is more reactive with the adsorption sites present on the surface of the wafer 200 than the first source gas under the same conditions is used as the second source gas. Also, for example, it is likely to hold when a gas having no cyclic structure in the molecule is used as the first source gas and a gas having a cyclic structure (e.g., a five-membered carbon ring structure) in the molecule is used as the second source gas. Also, it is likely to hold when a gas having more ligands than the ligand of the first source gas is used as the second source gas. Also, a gas with a larger molecular weight is sometimes more likely to adsorb on the surface of the wafer 200 by van der Waals forces with the surface of the wafer 200. Therefore, when a gas having a molecular weight larger than that of the first source gas is used as the second source gas, the second source gas may sometimes be more likely to adsorb on the surface of the wafer 200 than the first source gas under the same conditions. For example, in the above aspect, the case where the first processing gas includes a first source gas and a first reaction gas containing a first element, and the second processing gas includes a second source gas and a second reaction gas containing a second element has been described. However, the present invention is not limited to these aspects. For example, the first processing gas may not include the first reaction gas, and the second processing gas may not include the second reaction gas. In other words, in the first film formation, the first reaction gas supply step (step A3) may not be performed, and in the second film formation, the second reaction gas supply step (step B3) may not be performed. In such cases, the same effects as the above aspects are also obtained. For example, in the above aspect, the case where the first reforming gas is supplied once in step A1 has been described. However, the present invention is not limited to these aspects. For example, in step A1, the first reforming gas can be supplied in multiple times, and during that time, the inside of the processing chamber 201 can be rinsed and evacuated. In this case, the same effects as the above aspects are also obtained. Also, the same applies to the supply of the first source gas, the first reaction gas, the second reforming gas, the second source gas, and the second reaction gas in steps A2, A3, B1, B2, and B3, respectively. For example, in the above aspect, the case where steps A1, A2, and A3 are sequentially performed a predetermined number of times in the first film formation has been described. However, the present invention is not limited to these aspects. For example, after performing steps A1, A2, and A3 a predetermined number of times, only steps A2 and A3 may be performed a predetermined number of times. In this case, the same effect as the above aspect is also obtained. Also, the same applies to the second film formation (steps B1, B2, and B3). For example, in step B1, it may be set such that the partial pressure of the second reforming gas is less than the partial pressure of the first reforming gas in step A1, while the supply time of the second reforming gas is longer than the supply time of the first reforming gas in step A1. By the above operation, an increase in the adsorption amount of the second reforming gas to the deep part side 302 can be suppressed, while the adsorption amount of the second reforming gas to the opening part side 301 can be increased. Therefore, the effect of the above aspect can be further improved. For example, it is preferably such that the supply flow rate of the second reforming gas in step B1 is less than the supply flow rate of the first reforming gas in step A1 (see FIG. 5). With these aspects, the partial pressure of the second reforming gas in step B1 can be made less than the partial pressure of the first reforming gas in step A1, and thus the amount of the second reforming gas adsorbed to the deep part side 302 of the recess 300 in step B1 can be made less than the amount of the first reforming gas adsorbed to the deep part side 302 of the recess 300 in step A1. Thereby, the same effect as the above aspect can be obtained. For example, in the above aspect, as shown in FIG. 6(a) for example, the case where the recess 300 provided in the wafer 200 has an opening facing the space for processing the wafer 200 has been described. However, the present invention is not limited to these aspects. For example, the recess provided in the substrate may also have, as shown in FIG. 7: a first recess having an opening facing the space for processing the substrate; and a second recess having an opening inside the first recess. Further, inside the substrate, for example, a plurality of pillars may be formed so as to cross the second recess in the same direction as the depth direction (e.g., the vertical direction) of the first recess. A space through which the supplied gas can communicate is formed between the respective pillars in the second recess. When the substrate having such a structure is processed by the above aspect, a film is formed on the surfaces of the first recess, the second recess, and the pillars. When using such a substrate, the same effect as the above aspect can also be obtained. For example, in the above aspect, the case where a film containing a first element and a second element is formed on the surface of the recess 300 provided in the wafer 200 has been described. However, the present invention is not limited to these aspects. For example, by forming the film containing the first element and the second element a predetermined number of times (one or more times), the recess 300 can be filled with the film containing the first element and the second element (fill film formation, bottom-up film formation). In this case, the amount and size of the voids (seams) present in the film can be reduced. Further, for example, in the above aspect, the case where a film containing a first element and a second element is formed on the surface of the recess 300 provided in the wafer 200 has been described. However, the present invention is not limited to these aspects. For example, when the wafer 200 has a first surface and a second surface different from the first surface, and the second processing gas (second source gas and / or second reaction gas) is a gas that is more easily adsorbed on the first surface than the first processing gas (first source gas and / or first reaction gas) under the same conditions, steps of supplying gases corresponding to the first reforming gas, the first processing gas, the second reforming gas, and the second processing gas, respectively, may be performed to selectively form a film containing the first element and the second element on the second surface. In such cases, step B1 is performed under the condition that the second reforming gas is more easily adsorbed on the first surface than the first reforming gas under the same conditions. Thereby, film formation on the first surface can be suppressed, that is, selective cracking can be suppressed. The processes used in each process are preferably prepared separately according to the processing content and are previously recorded and stored in the memory device 121c via a telecommunication line and an external memory device 123. Further, preferably, at the start of each process, the CPU 121a appropriately selects a suitable process from a plurality of processes recorded and stored in the memory device 121c according to the processing content. Thereby, films of various film types, composition ratios, film qualities, and film thicknesses can be formed with good reproducibility in one substrate processing apparatus. Also, the burden on the operator can be reduced, and each process can be started quickly while avoiding operation errors. The above processes are not limited to newly created ones. For example, they can also be prepared by changing existing processes already installed in the substrate processing apparatus. In the case of changing a process, the changed process can also be installed in the substrate processing apparatus via a telecommunication line and a recording medium on which the process is recorded. Further, the input / output device 122 of the existing substrate processing apparatus can also be operated to directly change the existing process already installed in the substrate processing apparatus. In the above aspect, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present invention is not limited to the above aspect. For example, it can also be suitably applied to the case of forming a film using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Further, in the above aspect, an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace has been described. The present invention is not limited to the above aspect and can also be suitably applied to the case of forming a film using a substrate processing apparatus having a cold-wall type processing furnace. Also, each process can be performed by the same processing steps and processing conditions as those in the above aspect and modified examples to obtain the same effects as those in the above aspect and modified examples. The above aspects or modified examples can be used in appropriate combinations. The processing programs and processing conditions at this time can be set to be the same as, for example, the processing programs and processing conditions in the above aspects or modified examples. 115: Wafer elevator 115s: Gate switch mechanism 121: Controller 121a: CPU 121b: RAM 121c: Memory device 121d: I / O port 121e: Internal bus 122: Input / output device 123: External memory device 200: Wafer (substrate) 201: Processing chamber 202: Processing furnace 203: Reaction tube 207: Heater 209: Manifold 217: Wafer boat 218: Heat insulation plate 219: Sealing cover 219s: Gate 220a, 220b, 220c: O-ring 231: Exhaust pipe 231a: Exhaust port 232a, 232b, 232c, 232d, 232e, 232f, 232g, 232h, 232i: Gas supply pipe 241a, 241b, 241c, 241d, 241e, 241f, 241g, 241h, 241i: Mass flow controller (MFC) 243a, 243b, 243c, 243d, 243e, 243f, 243g, 243h, 243i: Valve 244: APC valve 245: Pressure sensor 246: Vacuum pump 248: Agglomerated supply system 249a, 249b, 249c: Nozzle 250a, 250b, 250c: Gas supply hole 255: Rotating shaft 263: Temperature sensor 267: Rotating mechanism 300: Recess 301: Opening side 302: Deep part side L: Straight line D: Spacing distance FIG. 1 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in various aspects of the present invention, showing a diagram of the processing furnace portion in a longitudinal sectional view. FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in various aspects of the present invention, showing a diagram of the processing furnace portion in a sectional view taken along line A-A of FIG. 1. FIG. 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus suitable for use in various aspects of the present invention, showing a diagram of the control system of the controller 121 in a block diagram. FIG. 4 is a diagram showing an example of a substrate processing timing in one aspect of the present invention. FIG. 5 is a diagram showing an example of a substrate processing timing in one aspect of the present invention. FIG. 6(a) is a diagram showing the adsorption position of a first modifying gas in a concave portion of a wafer. FIG. 6(b) is a diagram showing the adsorption position of a first processing gas supplied to the wafer after the first modifying gas is adsorbed in the concave portion of the wafer. FIG. 6(c) is a diagram showing a first film formed after a cycle including a step of supplying the first modifying gas to the wafer and a step of supplying the first processing gas is repeated a predetermined number of times. FIG. 6(d) is a diagram showing the adsorption position of a second modifying gas in a concave portion of the wafer after the first film is formed. FIG. 6(e) is a diagram showing the adsorption position of a second processing gas supplied to the wafer after the second modifying gas is adsorbed on the first film. FIG. 6(f) is a diagram showing a second film formed after a cycle including a step of supplying the second modifying gas to the wafer and a step of supplying the second processing gas is repeated a predetermined number of times. FIG. 7 is a diagram showing an example of a first concave portion and a second concave portion provided in a concave portion on the surface of a wafer. 300: Concave portion 301: Opening side 302: Deep side

Claims

1. A substrate processing method comprising the steps of forming a film containing a first element and a second element by performing the following steps (a) and (b): (a) performing the following steps (a1) and (a2); (a1) supplying a first modified gas to the substrate; (a2) supplying the substrate with a first raw material gas having the first element; (b) performing the following steps (b1) and (b2); (b1) supplying a second modified gas to the substrate; (b2) supplying the substrate with a second raw material gas having the second element and being more easily adsorbed onto the surface of the substrate than the first raw material gas under the same conditions; (b1) is performed under the condition that the second modified gas is more easily adsorbed onto the surface of the substrate than the first modified gas supplied in (a1).

2. The substrate processing method as described in claim 1, wherein, The above-mentioned substrate has a recessed portion.

3. The substrate processing method as described in claim 1, wherein, The above-mentioned membrane is a laminated membrane comprising a first membrane containing the first element and a second membrane containing the second element.

4. The substrate processing method as described in claim 1, wherein, The first modified gas is a gas that inhibits the reaction between the first raw material gas and the surface of the substrate, and the second modified gas is a gas that inhibits the reaction between the second raw material gas and the surface of the substrate.

5. The substrate processing method as described in claim 1, wherein, The molecular weight of the second raw material gas is greater than that of the first raw material gas.

6. The substrate processing method as described in claim 1, wherein, The reactivity of the second raw material gas to the surface of the substrate is higher than that of the first raw material gas to the surface of the substrate under the same conditions.

7. The substrate processing method as described in any of claims 1 to 6, wherein, The first modified gas and the second modified gas are different gases.

8. The substrate processing method as described in claim 7, wherein, The pressure in the space where the substrate in (b1) exists is less than the pressure in the space in (a1).

9. The substrate processing method as described in claim 7, wherein, The time for supplying the second modified gas to the substrate in (b1) is shorter than the time for supplying the first modified gas to the substrate in (a1).

10. The substrate processing method as described in claim 7, wherein, The partial pressure of the second modified gas in the space where the substrate exists in (b1) is less than the partial pressure of the first modified gas in the space in (a1).

11. The substrate processing method as described in claim 10, wherein, The time for supplying the second modified gas to the substrate in (b1) is longer than the time for supplying the first modified gas to the substrate in (a1).

12. The substrate processing method as described in claim 7, wherein, The adsorption capacity of the second modified gas on the surface of the substrate is higher than that of the first modified gas on the surface of the substrate.

13. The substrate processing method according to any one of claims 1 to 6, wherein, The first modified gas and the second modified gas are the same gas; (a1) and (b1) are performed in a manner that satisfies at least one of the following: the pressure in the space where the substrate exists in (b1) is less than the pressure in the space in (a1); the time for supplying the second modified gas to the substrate in (b1) is shorter than the time for supplying the first modified gas to the substrate in (a1); and the partial pressure of the second modified gas in the space where the substrate exists in (b1) is less than the partial pressure of the first modified gas in the space in (a1).

14. The substrate processing method as described in claim 2, wherein, The aforementioned recess has: a first recess having an opening facing the space for processing the substrate; and a second recess having an opening formed on the surface of the first recess that serves as a sidewall.

15. The substrate processing method according to any one of claims 1 to 6, wherein, In steps (a1) and (a2), the following step is further performed: (a3) ​​supplying the first reaction gas to the substrate.

16. The substrate processing method according to any one of claims 1 to 6, wherein, In steps (b1) and (b2), the following step is further performed: (b3) supplying the substrate with the second reaction gas.

17. A method for manufacturing a semiconductor device, comprising the steps of forming a film containing a first element and a second element by performing the following steps (a) and (b): (a) performing the following steps (a1) and (a2); (a1) supplying a first modified gas to a substrate; (a2) supplying a first raw material gas having the first element to the substrate; (b) performing the following steps (b1) and (b2); (b1) supplying a second modified gas to the substrate; (b2) supplying a second raw material gas having the second element to the substrate, which is more easily adsorbed onto the surface of the substrate than the first raw material gas under the same conditions; (b1) is performed under the condition that the second modified gas is more easily adsorbed onto the surface of the substrate than the first modified gas supplied in (a1).

18. A substrate processing apparatus comprising: a first modified gas supply unit supplying a first modified gas to a substrate; a first raw material gas supply unit supplying a first raw material gas having a first element to the substrate; a second modified gas supply unit supplying a second modified gas to the substrate; a second raw material gas supply unit supplying a second raw material gas having a second element and being more easily adsorbed onto the surface of the substrate than the first raw material gas under the same conditions; and a control unit configured to control the first modified gas supply unit, the first raw material gas supply unit, the second modified gas supply unit, and the second raw material gas supply unit in a manner capable of performing the following processes, the processes including performing (a) and (b) the following processes to form a film containing the first element and the second element; (a) performing the following processes (a1) and (a2); (a1) the process of supplying the first modified gas to the substrate; (a2) the process of supplying the first raw material gas to the substrate. (b) Perform the following processes (b1) and (b2); (b1) supply the second modified gas to the substrate; (b2) supply the second raw material gas to the substrate; (b1) is performed under the condition that the second modified gas is more easily adsorbed onto the surface of the substrate than the first modified gas supplied in (a1).

19. A program that uses a computer to execute a program on a substrate processing apparatus, the program comprising performing the following (a) and (b) to form a film containing a first element and a second element: (a) performing the following (a1) and (a2); (a1) supplying a first modified gas to the substrate; (a2) supplying a first raw material gas having the first element to the substrate; (b) performing the following (b1) and (b2); (b1) supplying a second modified gas to the substrate; (b2) supplying a second raw material gas having the second element to the substrate, which is more easily adsorbed onto the surface of the substrate than the first raw material gas under the same conditions; (b1) is performed under the condition that the second modified gas is more easily adsorbed onto the surface of the substrate than the first modified gas supplied in (a1).

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