Method for manufacturing semiconductor device, substrate processing apparatus, and recording medium

Abstract

This invention relates to a method for manufacturing semiconductor devices, a substrate processing apparatus, and a recording medium. It comprises a process for forming a film on a substrate by repeating a predetermined number of cycles of a step (a) of forming a first layer by supplying raw materials to the substrate at different times and a step (b) of modifying the first layer by supplying a reactant to the substrate to form a second layer. In step (a), the following steps are performed sequentially: step (a-1), where raw materials are supplied to the substrate simultaneously with an inert gas supplied from a first supply unit at a first flow rate, and an inert gas is supplied from a second supply unit at a second flow rate; step (a-2), where raw materials are supplied to the substrate simultaneously with an inert gas supplied from the first supply unit at a third flow rate, or, with the supply of inert gas from the first supply unit stopped, raw materials are supplied from the first supply unit, and an inert gas is supplied from the second supply unit at a fourth flow rate.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201811015099.7, filed on August 31, 2018, entitled "Method for manufacturing a semiconductor device, substrate processing apparatus and recording medium". Technical Field

[0002] This invention relates to a method for manufacturing semiconductor devices, a substrate processing apparatus, and a recording medium. Background Technology

[0003] As part of the manufacturing process of semiconductor devices, a process of forming a film on a substrate is sometimes performed (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-118462 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The purpose of this invention is to provide a technique for controlling the in-plane thickness distribution of a film formed on a substrate.

[0009] Methods for solving problems

[0010] According to one aspect of the present invention, a technique is provided comprising a process of forming a film on a substrate by performing the following steps non-simultaneously a predetermined number of cycles: step (a), forming a first layer by supplying a raw material to the substrate; step (b), modifying the first layer by supplying a reactant to the substrate to form a second layer, wherein, in (a), the following steps (a-1) and (a-2) are performed sequentially: step (a-1), supplying the raw material to the substrate while simultaneously supplying an inactive gas from a first supply unit at a first flow rate, and supplying the inactive gas from a second supply unit disposed adjacent to the first supply unit at a second flow rate; step (a-2), supplying the substrate with the inactive gas from the first supply unit at a third flow rate smaller than both the first and second flow rates while simultaneously supplying the raw material, and supplying the inactive gas from the second supply unit at a fourth flow rate; or, supplying the substrate with the raw material from the first supply unit while the supply of the inactive gas from the first supply unit is stopped, and supplying the inactive gas from the second supply unit at a fourth flow rate.

[0011] This application relates to the following items.

[0012] Item 1. A method for manufacturing a semiconductor device, comprising a step of forming a film on a substrate by performing the following steps (a) and (b) non-simultaneously a predetermined number of cycles:

[0013] Step (a): The first layer is formed by supplying raw materials to the substrate;

[0014] Step (b) involves supplying a reactant to the substrate to modify the first layer, forming a second layer.

[0015] In process (a), the following processes (a-1) and (a-2) are performed sequentially:

[0016] In step (a-1), an inactive gas is supplied to the substrate from a first supply section at a first flow rate, and the raw material is supplied simultaneously. The inactive gas is also supplied from a second supply section disposed adjacent to the first supply section at a second flow rate.

[0017] In step (a-2), for the substrate, an inactive gas is supplied from the first supply unit at a third flow rate smaller than both the first and second flow rates, and the raw material is supplied simultaneously, while an inactive gas is supplied from the second supply unit at a fourth flow rate; or, for the substrate, the raw material is supplied from the first supply unit while the supply of inactive gas from the first supply unit is stopped, and an inactive gas is supplied from the second supply unit at a fourth flow rate.

[0018] Item 2. The method for manufacturing a semiconductor device according to Item 1, wherein the execution time of step (a-1) is shorter than the execution time of step (a-2).

[0019] Item 3. The method for manufacturing a semiconductor device according to Item 1, wherein the partial pressure of the raw material in step (a-1) is less than the partial pressure of the raw material in step (a-2).

[0020] Item 4. The method for manufacturing a semiconductor device according to Item 1, wherein step (a-1) is performed during the period when the adsorption state of the main element constituting the film contained in the raw material is in a pseudo-unsaturated state.

[0021] Item 5. The method for manufacturing a semiconductor device according to Item 1, wherein step (a-2) is performed during the period when the adsorption state of the main element constituting the film contained in the raw material is in a pseudo-saturated state.

[0022] Item 6. The method of manufacturing a semiconductor device according to Item 1, wherein step (a-1) is performed during a period in which the formation rate of the first layer changes from a first rate to a second rate smaller than the first rate.

[0023] Item 7. The method of manufacturing a semiconductor device according to Item 1, wherein step (a-2) is performed during the period after the formation rate of the first layer changes from a first rate to a second rate smaller than the first rate.

[0024] Item 8. A method for manufacturing a semiconductor device according to Item 1, wherein the amount of the raw material reaching the center of the substrate in step (a-1) is greater than the amount of the raw material reaching the center of the substrate in step (a-2).

[0025] Item 9. A method for manufacturing a semiconductor device according to Item 1, wherein, in step (a-1), the amount of the raw material reaching the center of the substrate is greater than the amount of the raw material reaching the outer periphery of the substrate.

[0026] Item 10. A method for manufacturing a semiconductor device according to Item 1, wherein the concentration of the raw material at the central portion of the substrate in step (a-1) is higher than the concentration of the raw material at the central portion of the substrate in step (a-2).

[0027] Item 11. A method for manufacturing a semiconductor device according to Item 1, wherein, in step (a-1), the concentration of the raw material at the central portion of the substrate is higher than the concentration of the raw material at the outer periphery of the substrate.

[0028] Item 12. A method for manufacturing a semiconductor device according to Item 1, wherein the thickness distribution of the film formed on the substrate in the plane of the substrate is finely adjusted by adjusting the fourth flow rate.

[0029] Item 13. A method for manufacturing a semiconductor device according to Item 1, wherein, in step (a-1), the supply of an inactive gas from the first supply unit begins before the supply of the raw material.

[0030] Item 14. A method for manufacturing a semiconductor device according to Item 1, wherein the second supply section has a plurality of supply sections disposed on both sides of the first supply section, sandwiching the first supply section.

[0031] Item 15. A method for manufacturing a semiconductor device according to Item 1, wherein the first flow rate and the second flow rate are each greater than the supply flow rate of the raw material in step (a-1).

[0032] Item 16. A method for manufacturing a semiconductor device according to Item 1, wherein the fourth flow rate is greater than the supply flow rate of the raw material in step (a-2).

[0033] Item 17. A method for manufacturing a semiconductor device according to Item 1, wherein the third flow rate is made less than the supply flow rate of the raw material in step (a-2).

[0034] Item 18. A method for manufacturing a semiconductor device according to Item 1, wherein, in step (a-2), the supply of inactive gas from the first supply unit is stopped, and the third flow rate is zero.

[0035] Item 19, a substrate processing apparatus, comprising:

[0036] A processing chamber for substrate treatment;

[0037] A raw material supply system for supplying raw materials to the substrate within the processing chamber;

[0038] A reactant supply system for supplying reactants to the substrate within the processing chamber;

[0039] An inactive gas supply system for supplying inactive gas to the substrate within the processing chamber; and

[0040] The control unit controls the raw material supply system, the reactant supply system, and the inactive gas supply system in a manner that forms a film on the substrate by performing the following processes (a) and (b) asynchronously a predetermined number of cycles within the processing chamber:

[0041] Process (a), supplying the raw material to the substrate to form a first layer;

[0042] Process (b) involves supplying the reactant to the substrate to modify the first layer, forming a second layer.

[0043] In process (a), the following processes (a-1) and (a-2) are performed sequentially:

[0044] Process (a-1): For the substrate, the raw material is supplied simultaneously with the inactive gas supplied from the first supply section at a first flow rate, and the inactive gas is supplied from the second supply section disposed adjacent to the first supply section at a second flow rate.

[0045] Process (a-2): For the substrate, an inactive gas is supplied from the first supply section at a third flow rate smaller than both the first and second flow rates, and the raw material is supplied simultaneously; and an inactive gas is supplied from the second supply section at a fourth flow rate; or, for the substrate, the raw material is supplied from the first supply section while the supply of inactive gas from the first supply section is stopped, and an inactive gas is supplied from the second supply section at a fourth flow rate.

[0046] Item 20. A computer-readable recording medium recording a program by which a substrate processing apparatus is operated by a computer to form a film on a substrate by performing a predetermined number of cycles of steps (a) and (b) performed asynchronously within the processing chamber of the substrate step apparatus:

[0047] Step (a) involves supplying raw materials to the substrate to form the first layer;

[0048] Step (b) involves supplying a reactant to the substrate to modify the first layer, forming a second layer.

[0049] In step (a), the following steps (a-1) and (a-2) are performed sequentially:

[0050] Step (a-1): The substrate is supplied with the raw material while the inactive gas is supplied from the first supply section at a first flow rate, and the inactive gas is supplied from the second supply section disposed adjacent to the first supply section at a second flow rate.

[0051] Step (a-2): For the substrate, an inactive gas is supplied from the first supply section at a third flow rate smaller than both the first and second flow rates, and the raw material is supplied simultaneously; and an inactive gas is supplied from the second supply section at a fourth flow rate; or, for the substrate, the raw material is supplied from the first supply section while the supply of inactive gas from the first supply section is stopped, and an inactive gas is supplied from the second supply section at a fourth flow rate.

[0052] Invention Effects

[0053] According to the present invention, the in-substrate film thickness distribution of the film formed on the substrate can be controlled. Attached Figure Description

[0054] Figure 1 : This is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in embodiments of the present invention, and is a diagram showing the processing furnace portion in longitudinal cross-section.

[0055] Figure 2 This is a schematic diagram of a portion of a vertical processing furnace of a substrate processing apparatus suitable for use in embodiments of the present invention, and is based on... Figure 1 The AA-line cross-section diagram shows a portion of the processing furnace.

[0056] Figure 3 : This is a schematic configuration diagram of the controller of a substrate processing apparatus suitable for use in embodiments of the present invention, and a block diagram showing the control system of the controller.

[0057] Figure 4 : A diagram illustrating the film-forming sequence of one embodiment of the present invention.

[0058] Figure 5 : A graph illustrating the change in the formation rate of the first layer on the substrate.

[0059] Figure 6 (a) and (b) are cross-sectional views showing a modified example of the vertical processing furnace, and are shown with the reaction tube, buffer chamber and nozzle partially extracted.

[0060] Figure 7 (a) is a graph showing the evaluation results of the in-plane film thickness distribution of the substrate in the embodiment, and (b) is a graph showing the evaluation results of the in-plane film thickness distribution of the substrate in the comparative example.

[0061] Explanation of reference numerals in the attached figures

[0062] 200 wafers (substrates)

[0063] 249a Nozzle (First Supply Department)

[0064] 249b Nozzle (Second Supply Section)

[0065] 249c nozzle (second supply section) Detailed Implementation

[0066] <One embodiment of the present invention>

[0067] The following is for reference Figures 1-5 This describes one embodiment of the present invention.

[0068] (1) Composition of substrate processing device

[0069] like Figure 1 As shown, the processing furnace 202 has a heater 207 as a heating mechanism (temperature control unit). The heater 207 is cylindrical and is vertically mounted by being supported by a retaining plate. The heater 207 also functions as an activation mechanism (activation unit) that activates (excites) the gas by heat.

[0070] A reaction tube 203 is arranged concentrically with the heater 207 inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and is formed into a cylindrical shape that is closed at the top and open at the bottom. A manifold 209 is arranged concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and is formed into a cylindrical shape that is open at both the top and bottom. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing component. The reaction tube 203 is installed vertically, just like 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 hollow part of the cylindrical processing container. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate. Processing of the wafer 200 is performed within the processing chamber 201.

[0071] Inside the processing chamber 201, nozzle 249a, serving as a first supply unit, and nozzles 249b and 249c, serving as second supply units, are arranged to penetrate the side wall of the manifold 209. Gas supply pipes 232a and 232c are connected to nozzles 249a and 249c, respectively. The second supply unit is different from the first supply unit and is arranged adjacent to the first supply unit. Nozzles 249a, 249b, and 249c are different nozzles, and nozzles 249b and 249c are arranged adjacent to nozzle 249a.

[0072] On gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c, serving as flow controllers (flow control units), and valves 243a to 243c, serving as on / off valves, are sequentially installed from the upstream side of the airflow. Gas supply pipes 232e and 232d are connected to gas supply pipes 232a and 232b, respectively, downstream of valves 243a and 243b. On gas supply pipes 232e and 232d, MFCs 241e and 241d and valves 243e and 243d are sequentially installed from the upstream side of the airflow.

[0073] like Figure 2As shown, nozzles 249a to 249c are respectively arranged vertically from the lower part of the inner wall of the reaction tube 203 upwards and towards the arrangement direction of the wafer 200 within a ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200 when viewed from above. That is, nozzles 249a to 249c are respectively arranged along the wafer arrangement area, in a region horizontally surrounding the wafer arrangement area to the side of the wafer arrangement area of ​​the wafer 200. Nozzle 249a is arranged so that it clamps the center of the wafer 200 that is loaded into the processing chamber 201 when viewed from above and is aligned with the exhaust port 231a described later. Nozzles 249b and 249c are arranged on both sides of nozzle 249a, that is, nozzles 249b and 249c are arranged so that they clamp nozzle 249a from both sides along the inner wall of the reaction tube 203 (the outer periphery of the wafer 200). Gas supply holes 250a-250c are respectively provided on the side of nozzles 249a-249c for supplying gas. Each gas supply hole 250a-250c opens opposite the exhaust port 231a when viewed from above, and can supply gas toward the wafer 200. Multiple gas supply holes 250a-250c are provided from the lower part to the upper part of the reaction tube 203.

[0074] A halosilane gas containing Si (a designated element for the membrane) and a halogen element is supplied as a raw material (raw material gas) into the processing chamber 201 via gas supply pipe 232a, MFC 241a, valve 243a, and nozzle 249a. The raw material gas is a gaseous raw material, such as the gas obtained by vaporizing a raw material that is liquid at room temperature and pressure, or a raw material that is gaseous at room temperature and pressure. A halosilane is a silane containing a halogen group. Halogen groups include chlorine, fluorine, bromine, and iodine groups. That is, halogen groups include halogen elements such as chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). For example, a raw material gas containing Si and Cl, i.e., a chlorosilane gas, can be used as the halosilane gas. The chlorosilane gas functions as a Si source. For example, hexachlorosilane (Si₂Cl₆, abbreviated as HCDS) gas can be used as the chlorosilane gas.

[0075] A nitrogen-containing gas, specifically hydrogen nitride, is supplied to the processing chamber 201 from the gas supply pipe 232b via MFC 241b, valve 243b, and nozzle 249b. This hydrogen nitride acts as a reactant, with a chemical structure (molecular structure) different from the raw materials. The hydrogen nitride serves as a nitrogen source. For example, ammonia (NH3) gas can be used as the hydrogen nitride gas.

[0076] Nitrogen (N2) gas, for example, is supplied as an inactive gas to the processing chamber 201 through gas supply pipes 232c-232e via MFCs 241c-241e, valves 243c-243e, gas supply pipes 232c-232a, and nozzles 249c-249a. The N2 gas functions as a purge gas, carrier gas, dilution gas, etc., and also as a thickness distribution control gas to control the in-plane thickness distribution of the film formed on the wafer 200.

[0077] The raw material supply system mainly consists of gas supply pipe 232a, MFC 241a, and valve 243a. The reactant supply system mainly consists of gas supply pipe 232b, MFC 241b, and valve 243b. The inactive gas supply system mainly consists of gas supply pipes 232c-232e, MFC 241c-241e, and valves 243c-243e.

[0078] Any or all of the aforementioned gas supply systems can be configured as an integrated supply system 248 comprising valves 243a-243e, MFCs 241a-241e, etc. The integrated supply system 248 is configured such that it is connected to gas supply pipes 232a-232e respectively, and the supply of various gases into the gas supply pipes 232a-232e is controlled by the controller 121 described later; that is, the opening and closing of valves 243a-243e, and the flow regulation using MFCs 241a-241e, etc. The integrated supply system 248 is configured as an integral or separate integrated unit, and is configured such that it can be disassembled and reassembled relative to the gas supply pipes 232a-232e, etc., as an integrated unit, and that the integrated supply system 248 can be maintained, replaced, or added as an integrated unit.

[0079] An exhaust port 231a is connected to the lower side wall of the reaction tube 203 to exhaust the atmosphere inside the processing chamber 201. For example... Figure 2As shown, the exhaust port 231a is positioned opposite (facing) the nozzles 249a-249c (gas supply holes 250a-250c) when the wafer 200 is held in a top view. The exhaust port 231a can also be provided from the lower part of the side wall of the reaction tube 203 along the upper part, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246, which is a vacuum exhaust device, is connected to the exhaust pipe 231 via a pressure sensor 245, which is a pressure detector (pressure detection unit), and an APC (Auto Pressure Controller) valve 244, which is a pressure regulator (pressure regulation unit). The APC valve 244 is configured such that by opening and closing the valve while the vacuum pump 246 is operating, vacuum exhaust can be performed and stopped within the processing chamber 201. Furthermore, by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating, the pressure within the processing chamber 201 can be regulated. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 can be considered as being included in the exhaust system.

[0080] Below the manifold 209, a sealing cover 219, serving as a furnace opening cover, is provided to airtightly seal the lower opening of the manifold 209. The sealing cover 219 is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220b, serving as a sealing member, is provided on the upper surface of the sealing cover 219 and abuts against the lower end of the manifold 209. Below the sealing cover 219, a rotation mechanism 267 is provided to rotate the crystal boat 217 (described later). The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. The sealing cover 219 is configured to be vertically raised and lowered by a crystal boat lift 115, which is a lifting mechanism located outside the manifold 209. The crystal boat lift 115 is configured as a conveying device (conveyor) capable of moving the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219. Below the manifold 209, a gate 219s, serving as a furnace opening cover, is provided, which can airtightly seal the lower opening of the manifold 209 while the sealing cover 219 is lowered to remove the crystal boat 217 from the processing chamber 201. The gate 219s is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220c, serving as a sealing member, is provided on the upper surface of the gate 219s, abutting against the lower end of the manifold 209. The opening and closing actions (raising and lowering actions, rotating actions, etc.) of the gate 219s are controlled by the gate opening and closing mechanism 115s.

[0081] The crystal boat 217, serving as a substrate support, is configured to vertically arrange multiple wafers 200 (e.g., 25 to 200) in a horizontal orientation and with their centers aligned, providing multi-layer support; that is, the multiple wafers 200 are arranged with intervals between them. The crystal boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the crystal boat 217, a heat-insulating plate 218 made of a heat-resistant material such as quartz or SiC is supported in multiple layers.

[0082] A temperature sensor 263, serving as a temperature detector, is installed inside the reaction tube 203. The energizing of the heater 207 is adjusted based on the temperature information detected by the temperature sensor 263, thereby achieving the desired temperature distribution within the processing chamber 201. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0083] like Figure 3 As shown, the controller 121, serving as the control unit (control means), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, storage device 121c, and I / O port 121d. The RAM 121b, storage device 121c, and I / O port 121d are configured to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, such as a touch panel, is connected to the controller 121.

[0084] The storage device 121c is configured with, for example, flash memory or an HDD (Hard Disk Drive). Within the storage device 121c, a control program that controls the operation of the substrate processing apparatus and a process flow that describes the substrate processing steps and conditions (described later) are stored in a readable manner. The process flow functions as a program, combining elements in a way that enables the controller 121 to execute each step of the substrate processing described later and obtain a predetermined result. Hereinafter, the process flow, control program, etc., will also be collectively referred to as a program. Furthermore, the process flow will also be simply referred to as a process. In this specification, when using the term "program," sometimes it refers only to the process, sometimes only to the control program, or sometimes both. RAM 121b is configured as a memory area (working area) that temporarily holds programs, data, etc., read by the CPU 121a.

[0085] I / O port 121d is connected to the aforementioned MFC241a~241e, valves 243a~243e, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotating mechanism 267, crystal boat elevator 115, gate opening and closing mechanism 115s, etc.

[0086] CPU 121a is configured to read and execute control programs from storage device 121c, and to read processes from storage device 121c based on inputs such as operation commands from input / output device 122. CPU 121a is configured to control, in accordance with the read process contents, the flow regulation of various gases using MFCs 241a to 241e, the opening and closing of valves 243a to 243e, the opening and closing of APC valve 244 and the pressure regulation of APC valve 244 based on pressure sensor 245, the start and stop of vacuum pump 246, the temperature regulation of heater 207 based on temperature sensor 263, the rotation and rotation speed regulation of crystal boat 217 using rotating mechanism 267, the lifting and lowering of crystal boat 217 using crystal boat elevator 115, and the opening and closing of gate 219s using gate opening and closing mechanism 115s, etc.

[0087] The controller 121 can be configured by installing the program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a hard disk such as an HDD; an optical disk such as a CD; an optical disk such as an MO; or a semiconductor memory such as a USB memory. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium. Hereinafter, they will also be collectively referred to as recording media. When the term "recording medium" is used in this specification, it may refer only to the storage device 121c, only to the external storage device 123, or both. It should be noted that the program can be provided to the computer without using the external storage device 123, but rather using communication means such as a network or dedicated line.

[0088] (2) Substrate processing process

[0089] For a substrate processing sequence example, i.e. a film formation sequence example, in which a film is formed on a wafer 200 serving as a substrate using the aforementioned substrate processing apparatus as a step in the manufacturing process of a semiconductor device, the following applies: Figure 4 The following description will explain the operation of each component of the substrate processing apparatus, which is controlled by controller 121.

[0090] exist Figure 4 In the film formation sequence shown, a silicon nitride film (SiN film) containing Si and N is formed on the wafer 200 by performing the following steps A and B a predetermined number of times in a non-simultaneous manner: Step A, HCDS gas is supplied to the wafer 200 as a raw material (represented by A in the figure); and Step B, NH3 gas is supplied to the wafer 200 as a reactant (represented by B in the figure).

[0091] exist Figure 4In the film formation sequence shown, in step A, the following steps A1 and A2 are performed sequentially to control the in-plane thickness distribution (hereinafter also referred to as in-plane thickness distribution) of the SiN film formed on the wafer 200: Step A1 (denoted as A1 in the figure), while supplying N2 gas as an inactive gas from nozzle 249a, which serves as a first supply section, to the wafer 200, HCDS gas is supplied at a first flow rate, and N2 gas is supplied at a second flow rate from nozzles 249b and 249c, which are adjacent to nozzle 249a and serve as second supply sections; Step A2 (denoted as A2 in the figure), while supplying N2 gas from nozzle 249a at a third flow rate smaller than both the first and second flow rates, HCDS gas is supplied to the wafer 200, and N2 gas is supplied from nozzles 249b and 249c at a fourth flow rate; or, while stopping the supply of N2 gas from nozzle 249a, HCDS gas is supplied from nozzle 249a, and N2 gas is supplied from nozzles 249b and 249c at a fourth flow rate.

[0092] Here, as an example, the following situation will be explained: Using a bare wafer 200 with a small surface area and no uneven structure formed on its surface, the above-described film deposition sequence and flow control are used to make the in-plane thickness distribution of the SiN film the thickest at the center of the wafer 200, gradually thinning towards the outer periphery (hereinafter also referred to as "central convex distribution"). If a film with a central convex distribution can be formed on the bare wafer, a film with a flat film thickness distribution (hereinafter also referred to as "flat distribution") with minimal thickness variation from its center to its outer periphery can be formed on a pattern wafer (product wafer) with a large surface area obtained by forming a fine uneven structure on its surface.

[0093] Furthermore, as an example, the following situation will be explained: the first flow rate in step A1 is set to a flow rate greater than the second flow rate, and in step A2, the supply of N2 gas from nozzle 249a is stopped (the third flow rate is set to zero), and the fourth flow rate is made equal to the second flow rate.

[0094] For convenience, this instruction manual may sometimes also use... Figure 4 The film-forming sequence shown is represented as follows. The same representation is used in the descriptions of the following variations, etc.

[0095]

[0096] In this specification, when the term "wafer" is used, it sometimes refers to "the wafer itself" or "a laminate of a wafer and a specified layer, film, etc., formed on its surface." When the term "surface of the wafer" is used, it sometimes refers to "the surface of the wafer itself" or "the surface of a specified layer, film, etc., formed on the wafer." When described as "forming a specified layer (or film) on the wafer," it sometimes means "forming a specified layer directly on the surface of the wafer itself" or "forming a specified layer on a layer, etc., formed on the wafer." In this specification, the term "substrate" has the same meaning as when the term "wafer" is used.

[0097] (Chip filling ~ Crystal boat loading)

[0098] After multiple wafers 200 are loaded (wafer filling) onto the crystal boat 217, the gate 219s is moved by the gate opening and closing mechanism 115s, thereby opening the lower end opening of the current collector 209 (gate opening). Then, as... Figure 1 As shown, a crystal boat 217 supporting multiple wafers 200 is lifted by a crystal boat elevator 115 and moved (crystal boat loading) into the processing chamber 201. In this state, the sealing cover 219 is in a state where the lower end of the manifold 209 is sealed by means of an O-ring 220b.

[0099] (Pressure and temperature regulation)

[0100] To achieve the desired pressure (vacuum) within the processing chamber 201, i.e., the space where the wafer 200 exists, vacuum pump 246 performs vacuum venting (pressure reduction venting). At this time, pressure sensor 245 measures the pressure within the processing chamber 201, and APC valve 244 is controlled based on this measured pressure information. Furthermore, the wafer 200 within the processing chamber 201 is heated by heater 207 to achieve the desired film formation temperature. At this time, the energization of heater 207 is controlled based on temperature information detected by temperature sensor 263 to achieve the desired temperature distribution within the processing chamber 201. Additionally, the wafer 200 is rotated using rotation mechanism 267. Venting within the processing chamber 201, heating of the wafer 200, and rotation are all performed continuously, at least until the processing of the wafer 200 is completed.

[0101] (Film-forming steps)

[0102] Then, perform the following steps A and B in sequence.

[0103] [Step A]

[0104] In this step, HCDS gas is supplied to the wafer 200 inside the processing chamber 201. Specifically, valve 243a is opened, allowing HCDS gas to flow into the gas supply pipe 232a. The HCDS gas is flow-regulated using MFC 241a and supplied to the processing chamber 201 via nozzle 249a, and exhausted from exhaust port 231a. At this time, HCDS gas is supplied to the wafer 200. In step A, steps A1 and A2 are performed to supply N2 gas into the processing chamber 201 via nozzles 249a to 249c, details of which are described later.

[0105] In addition to the N2 gas supply conditions described later in steps A1 and A2, the processing conditions in step A can be exemplified as follows:

[0106] HCDS gas supply flow rate: 0.001–2 slm, preferably 0.01–1 slm

[0107] HCDS gas supply time: 1–120 seconds, preferably 1–60 seconds

[0108] Processing temperature: 250–800℃, preferably 400–700℃

[0109] Processing pressure: 1~2666Pa, preferably 67~1333Pa.

[0110] By supplying HCDS gas to the wafer 200 under the above conditions, a Si-containing layer containing Cl is formed on the outermost surface of the wafer 200 as a first layer. The Si-containing layer containing Cl is formed by: physical adsorption of HCDS onto the outermost surface of the wafer 200; or by using a substance obtained from a partial decomposition of HCDS (hereinafter, Si). x Cl y Si is chemically adsorbed onto the outermost surface of wafer 200; or it is deposited on the outermost surface of wafer 200 through thermal decomposition of HCDS. The Si-containing layer containing Cl can be HCDS, Si... x Cl y The adsorption layer (physical adsorption layer, chemisorption layer) can also be a Si layer containing Cl. It should be noted that in this specification, the Si layer containing Cl will also be referred to simply as the Si layer.

[0111] It should be noted that, due to the abundance of Si adsorption sites on the outermost surface of the wafer 200 before the HCDS gas is supplied, therefore, as Figure 5As shown, in the initial stage of HCDS gas supply, the first layer is formed at a relatively high formation rate, and this high formation rate is maintained for a specified period (period T1). Then, by continuing to supply HCDS gas, the formation of the first layer further progresses. However, if the amount of adsorption sites on the outermost surface of the wafer 200 decreases, a time (inflection point) will occur where the formation rate of the first layer significantly decreases. After the inflection point, the period before the adsorption of Si on the outermost surface of the wafer 200 reaches complete saturation (period T2) will maintain a significantly reduced formation rate. Hereinafter, the formation rate of the first layer during period T1 will be referred to as the first rate. Furthermore, the formation rate of the first layer during period T2 will be referred to as the second rate. The second rate is a rate less than the first rate (first rate > second rate).

[0112] According to the inventors' in-depth research, after the supply of HCDS gas to wafer 200 begins and the aforementioned inflection point is reached, a prolonged and continuous supply of HCDS gas is required to ensure complete saturation of Si adsorption on the outermost surface of wafer 200. One major reason for this is that steric hindrance sometimes formed on the surface of wafer 200 is eliminated during the film deposition process, causing Si to adsorb at hidden adsorption sites. Another major reason is that impurities attached to adsorption sites on the surface of wafer 200, which hinder Si adsorption at these sites, detach during the film deposition process, causing Si to adsorb at hidden adsorption sites. Based on these reasons, a prolonged and continuous supply of HCDS gas is required to ensure complete saturation of Si adsorption on wafer 200, during which T2 becomes a longer period than T1 (T1 < T2).

[0113] In this specification, the period T1, where the formation rate of the first layer is at a first rate and the adsorption of Si contained in the HCDS gas onto the substrate is in an unsaturated state, is referred to as a pseudo-unsaturated state. The period during which the adsorption of Si contained in the HCDS gas onto the substrate is in a pseudo-unsaturated state is also referred to as a pseudo-unsaturated period. Furthermore, the period T2, where the formation rate of the first layer is at a second rate and the adsorption of Si contained in the HCDS gas onto the substrate is unsaturated but close to saturation, is referred to as a pseudo-saturated state. The period during which the adsorption of Si contained in the HCDS gas onto the substrate is in a pseudo-saturated state is also referred to as a pseudo-saturated period.

[0114] It should be noted that during period T1, the HCDS gas supplied from nozzle 249a tends to be actively consumed at the outer periphery of wafer 200 and does not easily reach the center of wafer 200. Therefore, if the supply of HCDS gas to wafer 200 is stopped after the start of the supply of HCDS gas, for example, at a point before the inflection point, the thickness distribution of the first layer in the plane of wafer 200 (hereinafter also referred to as "the in-plane thickness distribution of the first layer") becomes the thinnest at the center of wafer 200 and gradually thickens as it approaches the outer periphery (hereinafter also referred to as "the central concave distribution").

[0115] On the other hand, by continuing to supply HCDS gas to the wafer 200 for an extended period after the initial supply of HCDS gas, for example, after reaching an inflection point, the consumption of HCDS gas at the outer periphery of the wafer 200 converges, and simultaneously, the amount of HCDS gas reaching the central portion of the wafer 200 can be gradually increased. Therefore, as a method to make the in-plane thickness distribution of the first layer approach a flat distribution from a centrally concave distribution, it is advisable to continue supplying HCDS gas to the wafer 200 for an extended period after reaching an inflection point.

[0116] However, this method suffers from several drawbacks: it increases gas costs; it increases the required time for step A, i.e., the processing time per cycle, or the total processing time, thereby reducing the productivity of the film-forming process. Furthermore, even though it is theoretically possible to make the in-plane thickness distribution of the first layer closer to a flat distribution from a centrally concave distribution, it is difficult to make it a centrally convex distribution.

[0117] Furthermore, during periods T1 and T2, when HCDS gas is supplied to the wafer 200, N2 gas is simultaneously supplied at high flow rates from nozzles 249b and 249c. This increases the pressure in the annular space (hereinafter referred to as the "annular space") between the inner wall of the reaction tube 203 and the wafer 200, compared to the case where N2 gas is not supplied at high flow rates from nozzles 249b and 249c. In this case, it is believed that the outflow of HCDS gas into the annular space can be suppressed, and the supply of HCDS gas to the center of the wafer 200 can be increased. Additionally, in this case, it is believed that the partial pressure (concentration) of HCDS gas in the annular space can be reduced, and the supply of HCDS gas to the outer periphery of the wafer 200 can be decreased. Therefore, as a method to make the in-plane thickness distribution of the first layer approach a flat distribution from a central concave distribution, and further approach a central convex distribution, it is possible to consider flowing N2 gas from nozzles 249b and 249c at a large flow rate, for example, a flow rate greater than that of HCDS gas, during periods T1 and T2.

[0118] However, in the above method, there is a situation where the formation rate of the first layer is reduced due to excessive dilution of HCDS gas, resulting in a decrease in the productivity of the film formation process.

[0119] Furthermore, based on in-depth research by the inventors, it was discovered that even if the supply of N2 gas from nozzles 249b and 249c during period T1, after the start of HCDS gas supply to wafer 200 but before the inflection point, is controlled in the manner described above, the following situation still exists: during period T1, it is difficult to change the trend of HCDS gas being actively consumed at the outer periphery of wafer 200 and not easily reaching the center of wafer 200. For example, the inventors found that even if the supply of N2 gas from nozzles 249b and 249c during period T1 is controlled in the manner described above, depending on the type of raw material gas, the following situation still exists: the tendency for the in-plane thickness distribution of the first layer formed during period T1 to be a centrally concave distribution does not change, and it is difficult to make the distribution flat or centrally convex. Thus, using only the above method, it is impossible to sufficiently control the thickness distribution of the first layer.

[0120] Furthermore, based on in-depth research by the inventors, it was discovered that even if the supply of N2 gas from nozzles 249b and 249c in period T2 is controlled in the manner described above after the inflection point is reached when HCDS gas is first supplied to wafer 200, the following situation still exists: it is difficult to change the in-plane thickness distribution of the first layer formed in period T1. For example, the inventors found that even if the supply of N2 gas from nozzles 249b and 249c in period T2 is controlled in the manner described above, depending on the type of raw material gas, the following situation still exists: it is difficult to change the trend of the in-plane thickness distribution of the first layer formed in period T1 in period T2, and it is difficult to make the distribution approach a flat distribution or further approach a centrally convex distribution.

[0121] Therefore, in this embodiment, to avoid the aforementioned problems, in step A, steps A1 and A2 are performed sequentially from the start of supplying HCDS gas to the wafer 200 until the HCDS gas supply to the wafer 200 is stopped. Specifically, step A1 is performed during the period T1, which is the period before the inflection point occurs when the formation rate of the first layer changes from the first rate to the second rate. Step A2 is performed during the period T2, which is after the inflection point occurs when the formation rate of the first layer changes from the first rate to the second rate. To improve the controllability of the in-plane thickness distribution of the SiN film formed on the wafer 200, it is effective not to perform step A2 during period T1. As described above, since period T1 is shorter than period T2, the execution time of step A1 is shorter than the execution time of step A2.

[0122] The details of steps A1 and A2 are explained below.

[0123] In step A1, valves 243e and 243a are opened to supply N2 gas to the wafer 200 from nozzle 249a at a first flow rate, while simultaneously supplying HCDS gas. Valves 243d and 243c are also opened to supply N2 gas from nozzles 249b and 249c, which are adjacent to nozzle 249a, at a second flow rate. Here, the second flow rate refers to the total flow rate of N2 gas supplied from each of nozzles 249b and 249c. The flow rates of N2 gas supplied from each of nozzles 249b and 249c can be set to be approximately equal.

[0124] In step A1, by controlling the supply of N2 gas from nozzle 249a in the manner described above, the N2 gas supplied from nozzle 249a can function as a carrier gas, pushing the HCDS gas supplied from nozzle 249a from the outer periphery of wafer 200 towards the center. Using this effect, the amount of HCDS gas reaching the center of wafer 200 in step A1 is greater than the amount of HCDS gas reaching the center of wafer 200 in step A2 (described later). Therefore, the concentration of HCDS gas at the center of wafer 200 in step A1 is higher than the concentration of HCDS gas at the center of wafer 200 in step A2. Furthermore, using the above effect, in step A1, the amount of HCDS gas reaching the center of wafer 200 is greater than the amount of HCDS gas reaching the outer periphery of wafer 200. Therefore, in step A1, the concentration of HCDS gas at the center of wafer 200 is higher than the concentration of HCDS gas at the outer periphery of wafer 200. As a result, in step A1, the formation rate of the first layer at the center of the wafer 200 is greater than the formation rate of the first layer at the outer periphery of the wafer 200. Furthermore, the in-plane thickness distribution of the first layer formed on the wafer 200 during period T1 is made to be a flat distribution, or even a convex distribution, rather than a centrally concave distribution.

[0125] Furthermore, in step A1, by controlling the supply of N2 gas from nozzles 249b and 249c in the manner described above, the pressure in the annular space can be increased compared to the case without such control. This suppresses the outflow of HCDS gas into the annular space and increases the amount of HCDS gas supplied to the center of the wafer 200. Additionally, by controlling the supply of N2 gas from nozzles 249b and 249c in the manner described above, the flow of N2 gas supplied from nozzles 249b and 249c toward the exhaust port 231a can act as a guide for HCDS gas supplied from nozzle 249a to the center of the wafer 200. This also increases the amount of HCDS gas supplied to the center of the wafer 200. Furthermore, it reduces the partial pressure of HCDS gas in the annular space and decreases the amount of HCDS gas supplied to the outer periphery of the wafer 200. As a result, in step A1, the formation rate of the first layer at the center of the wafer 200 can be increased compared to the formation rate when N2 gas is not supplied from nozzles 249b and 249c. Furthermore, the aforementioned effects of the N2 gas supplied from nozzle 249a can be obtained more reliably, namely, the effect of making the in-plane thickness distribution of the first layer formed on the wafer 200 flat and, more importantly, convex at the center.

[0126] It should be noted that, in step A1, it is preferable that at least one of the first flow rate and the second flow rate, preferably both of the above, is greater than the supply flow rate of the HCDS gas in step A1. This allows for a more reliable achievement of the aforementioned effect of making the in-plane thickness distribution of the first layer formed on the wafer 200 a flat distribution, and further, a centrally convex distribution. Additionally, in step A1, it is preferable that at least one of the flow rates of each N2 gas supplied from nozzles 249b and 249c, preferably both of the above, is greater than the supply flow rate of the HCDS gas in step A1. This allows for a more reliable achievement of the aforementioned effect of making the in-plane thickness distribution of the first layer formed on the wafer 200 a flat distribution, and further, a centrally convex distribution.

[0127] Additionally, in step A1, as Figure 4As shown, it is preferable to start the supply of N2 gas from nozzle 249a before the supply of HCDS gas. That is, it is preferable to start supplying HCDS gas to wafer 200 after the flow of N2 gas from nozzle 249a toward the center of wafer 200 has been pre-generated. This ensures that the N2 gas supplied from nozzle 249a functions as a carrier gas immediately after the HCDS gas supply begins. Furthermore, it can suppress excessive in-plane unevenness of HCDS gas concentration on wafer 200 at the start of HCDS gas supply. As a result, the in-plane thickness distribution of the first layer formed on wafer 200 can be stably and reproducibly controlled during period T1.

[0128] As a processing condition in step A1, an example can be given:

[0129] First flow rate (nozzle 249a): 3–20 slm, preferably 5–10 slm

[0130] Second flow rate (combined for nozzles 249b and 249c): 3–20 slm, preferably 5–10 slm

[0131] The implementation time of step A1 is 1 / 10 to 1 / 4 of the HCDS gas supply time in step A.

[0132] Other processing conditions are the same as those in step A above.

[0133] In step A2, MFC241e is adjusted to supply HCDS gas to the wafer 200 from nozzle 249a at a third flow rate smaller than both the first and second flow rates, while simultaneously supplying N2 gas. Alternatively, valve 243e is closed, and HCDS gas is supplied from nozzle 249a while the supply of N2 gas from nozzle 249a is stopped. MFCs 241d and 241c are adjusted to supply N2 gas from nozzles 249b and 249c at a fourth flow rate. Here, the third flow rate, like the second flow rate, refers to the total flow rate of N2 gas supplied from each of nozzles 249b and 249c. The flow rates of N2 gas supplied from each of nozzles 249b and 249c can be set to be approximately equal. It should be noted that, as described above, Figure 4 As an example, the following situation is shown: in step A2, the supply of N2 gas from nozzle 249a is stopped (making the third flow rate zero), and the fourth flow rate is made equal to the second flow rate (fourth flow rate = second flow rate).

[0134] In step A2, by controlling the supply of N2 gas from nozzle 249a in the manner described above, excessive dilution of the HCDS gas supplied to wafer 200 from nozzle 249a can be suppressed. As a result, the reduction in the formation rate of the first layer can be suppressed, and a decrease in the productivity of the film deposition process can be avoided. It should be noted that when N2 gas is supplied from nozzle 249a in step A2 (without setting the third flow rate to zero), the effect described in step A1, resulting from the N2 gas supplied from nozzle 249a acting as a carrier gas, can also be obtained in step A2. However, in this case, it is preferable to set the third flow rate to be lower than the supply flow rate of HCDS gas in step A2. As a result, the aforementioned effect of suppressing the reduction in the formation rate of the first layer can be reliably obtained. In addition, in step A2, when N2 gas is not supplied from nozzle 249a (with the third flow rate set to zero), the aforementioned effect of suppressing the reduction in the formation rate of the first layer can be obtained more reliably.

[0135] Furthermore, in step A2, by controlling the supply of N2 gas from nozzles 249b and 249c in the manner described above, for the same reasons as those stated in step A1, the amount of HCDS gas supplied to the center of wafer 200 can be increased, and the amount of HCDS gas supplied to the outer periphery of wafer 200 can be decreased. Additionally, the effects described in step A1, such as the flow of N2 gas supplied from nozzles 249b and 249c toward exhaust port 231a acting as a guide for the HCDS gas supplied from nozzle 249a to the center of wafer 200, can also be obtained in step A2. It should be noted that in step A2, when the fourth flow rate is greater than the HCDS gas supply flow rate in step A2, the effects described in step A1, such as the N2 gas supplied from nozzles 249b and 249c acting as a guide for the HCDS gas, can be obtained more reliably.

[0136] As a processing condition in step A2, an example can be given:

[0137] Third flow rate (nozzle 249a): 0–0.8 slm, preferably 0–0.2 slm

[0138] Fourth flow rate (total of nozzles 249b and 249c): 3 to 20 slm, preferably 5 to 10 slm. Implementation time of step A2: 3 / 4 to 9 / 10 of the HCDS gas supply time in step A.

[0139] Other processing conditions are the same as those in step A above.

[0140] After the first layer is formed on wafer 200, valve 243a is closed to stop the supply of HCDS gas to processing chamber 201. Furthermore, a vacuum is applied to processing chamber 201 to remove any remaining gases. At this time, valves 243c-243e are opened, and N2 gas is supplied to processing chamber 201 through nozzles 249c-249a. The N2 gas supplied from nozzles 249c-249a acts as a purging gas, thereby purging processing chamber 201 (purging step). During the purging step, the flow rate of N2 gas supplied from each nozzle 249c-249a is set to, for example, within the range of 0.1 to 2 slm. Other processing conditions are the same as those in step A described above.

[0141] In addition to HCDS gas, other chlorosilane gases such as monochlorosilane (SiH3Cl, abbreviated as MCS), dichlorosilane (SiH2Cl2, abbreviated as DCS), trichlorosilane (SiHCl3, abbreviated as TCS), tetrachlorosilane (SiCl4, abbreviated as STC), and octachlorotrisilane (Si3Cl8, abbreviated as OCTS) can also be used as raw materials.

[0142] In addition to N2, rare gases such as Ar, He, Ne, and Xe can also be used as inert gases. This is also true in step B described later.

[0143] [Step B]

[0144] After step A is completed, NH3 gas is supplied to the wafer 200, i.e., the first layer formed on the wafer 200, within the processing chamber 201. Specifically, valve 243b is opened, allowing NH3 gas to flow into the gas supply pipe 243b. The NH3 gas flow rate is regulated using MFC 241b, and it is supplied to the processing chamber 201 via nozzle 249b and exhausted from exhaust port 231a. At this time, NH3 gas is supplied to the wafer 200. It should be noted that at this time, at least any one of valves 243c to 243e can also be opened, allowing N2 gas to flow into the processing chamber 201 via nozzles 249c to 249a. Figure 4 The example shows a case where N2 gas is supplied from nozzles 249a and 249c but not from nozzle 249b.

[0145] As a processing condition in this step, an example can be given:

[0146] NH3 gas supply flow rate: 1~10slm

[0147] NH3 gas supply time: 1–120 seconds, preferably 1–60 seconds

[0148] N2 gas supply flow rate (per gas supply pipe): 0~2slm

[0149] Processing pressure: 1-4000 Pa, preferably 1-3000 Pa.

[0150] Other processing conditions are the same as those in step A.

[0151] By supplying NH3 gas to the wafer 200 under the aforementioned conditions, at least a portion of the first layer formed on the wafer 200 can be nitrided (modified). By modifying the first layer, a second layer, namely a SiN layer, containing Si and N, is formed on the wafer 200. During the formation of the second layer, impurities such as Cl contained in the first layer are converted into a gaseous substance containing at least Cl during the modification reaction of the first layer using NH3 gas, and are discharged from the processing chamber 201. Thus, the second layer becomes a layer with fewer impurities such as Cl compared to the first layer.

[0152] After the second layer is formed, valve 243b is closed to stop the supply of NH3 gas to the treatment chamber 201. Furthermore, using the same treatment steps and conditions as the purging step in step A, the gas and other gases remaining in the treatment chamber 201 are removed from the treatment chamber 201.

[0153] In addition to NH3 gas, other hydrogen nitride gases such as diazoxide (N2H2), hydrazine (N2H4), and N3H8 can also be used as reactants.

[0154] [Number of times stipulated for implementation]

[0155] By performing steps A and B asynchronously a predetermined number of times (n times, where n is an integer greater than or equal to 1), a SiN film with a predetermined composition and thickness can be formed on the wafer 200. It is preferable to repeat the above-described cycle multiple times. Specifically, it is preferable to repeat the cycle multiple times, making the thickness of the second layer formed in one cycle thinner than the desired film thickness, until the thickness of the SiN film formed by stacking the second layers reaches the desired film thickness.

[0156] (Post-purging and atmospheric pressure recovery)

[0157] After the film formation step is completed, N2 gas is supplied as purging gas into the processing chamber 201 from nozzles 249a to 249c, and exhaust is performed from exhaust port 231a. This purges the processing chamber 201, removing residual gases and reaction byproducts (post-purging). Then, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), restoring the pressure inside the processing chamber 201 to atmospheric pressure (atmospheric pressure restoration).

[0158] (Crystal boat unloading and chip removal)

[0159] The sealing cover 219 is lowered using the crystal boat lift 115, opening the lower end of the current collector 209. The processed wafer 200, supported on the crystal boat 217, is then moved from the lower end of the current collector 209 to the outside of the reaction tube 203 (crystal boat unloading). After unloading, the gate 219s moves, sealing the lower opening of the current collector 209 via the O-ring 220c (gate closing). The processed wafer 200, after being moved to the outside of the reaction tube 203, is removed from the crystal boat 217 (wafer removal).

[0160] (3) Effects of this implementation method

[0161] According to this embodiment, one or more of the following effects can be obtained.

[0162] (a) In step A, where HCDS gas is supplied to wafer 200 to form the first layer, by performing steps A1 and A2 as described above, the in-plane thickness distribution of the first layer can be controlled. As a result, the controllability of the in-plane thickness distribution of the SiN film formed on wafer 200 can be improved. For example, the in-plane thickness distribution of the SiN film formed on wafer 200, which is configured as a bare wafer, can be made to have a centrally convex distribution. Thus, when a patterned wafer is used as wafer 200, a SiN film with a flat distribution can be formed on the wafer 200.

[0163] It should be noted that the in-plane thickness distribution of the film formed on the wafer 200 depends on the surface area of ​​the wafer 200, which is believed to be caused by the so-called loading effect. The larger the surface area of ​​the wafer 200 to which the film is formed, the more raw materials such as HCDS gas are consumed at the outer periphery of the wafer 200, and the less likely they are to reach the center. As a result, the in-plane thickness distribution of the film formed on the wafer 200 tends to become a centrally concave distribution. According to this embodiment, even if a patterned wafer with a large surface area is used as the wafer 200, it is possible to freely control the in-plane thickness distribution of the film formed on the wafer 200 to correct it from a centrally concave distribution to a flat distribution, and further, to a centrally convex distribution.

[0164] (b) In step A, which supplies HCDS gas to the wafer 200 to form the first layer, by performing the above steps A1 and A2, the distribution of the SiN layer composition within the wafer 200 plane, i.e., the in-plane composition distribution of the SiN film formed on the wafer 200 (hereinafter also referred to as in-plane composition distribution), can be controlled. As a result, the controllability of the in-plane film composition distribution (hereinafter also referred to as in-plane film composition distribution) of the SiN film formed on the wafer 200 can be improved.

[0165] For example, when the in-plane thickness distribution of the SiN film formed on the wafer 200 is centrally convex, the film composition can be Si-rich in the central portion of the wafer 200 and N-rich in the outer periphery of the wafer 200. Alternatively, for example, when the in-plane thickness distribution of the SiN film formed on the wafer 200 is centrally concave, the film composition can be N-rich in the central portion of the wafer 200 and Si-rich in the outer periphery of the wafer 200. Furthermore, for example, when the in-plane thickness distribution of the SiN film formed on the wafer 200 is planar, the composition of the film can become uniform throughout the entire in-plane region of the wafer 200.

[0166] In this embodiment, by controlling the in-plane thickness distribution of the SiN film formed on the wafer 200, the in-plane composition distribution, i.e., the in-plane film quality distribution, of the SiN film formed on the wafer 200 can be controlled over a wide range, thereby improving its in-plane uniformity.

[0167] (c) In step A2, by controlling the supply of N2 gas from nozzle 249a in the manner described above, the dilution of HCDS gas can be reduced, and the decrease in the formation rate of the first layer can be suppressed. As a result, the efficiency of the first layer formation process can be suppressed, and the productivity of the film formation process can be avoided.

[0168] Furthermore, by making the execution time of step A1 shorter than that of step A2, the decrease in the formation rate of the first layer can be more effectively suppressed. That is, by making the execution time of step A1, which has a high degree of HCDS gas dilution, shorter than that of step A2, which has a low degree of HCDS gas dilution, the overall efficiency of the first layer formation process can be suppressed, and the productivity of the film formation process can be avoided.

[0169] (d) By performing steps A1 and A2 under the aforementioned processing conditions, the partial pressure of the HCDS gas in the processing chamber 201 in step A1 can be made lower than the partial pressure of the HCDS gas in the processing chamber 201 in step A2. By reducing the partial pressure of the HCDS gas in step A1 in this way, the controllability of the in-plane thickness distribution of the first layer formed in step A1 can be improved. As mentioned above, the in-plane thickness distribution in the initial stage of the formation of the first layer can be a major factor determining the final in-plane thickness distribution of the first layer. Therefore, the above effect is very important for improving the controllability of the in-plane thickness distribution of the SiN film formed on the wafer 200.

[0170] Furthermore, by reducing the partial pressure of the HCDS gas in step A1 in this way, the step coverage characteristic of the first layer formed in step A1 can be improved. This, in turn, enhances the step coverage characteristic of the SiN film formed on wafer 200.

[0171] (e) In step A1, by starting the supply of N2 gas from nozzle 249a before the supply of HCDS gas, the aforementioned effect of having the N2 gas supplied from nozzle 249a function as a carrier gas can be reliably obtained immediately after the start of the HCDS gas supply. Furthermore, excessive in-plane unevenness of the HCDS gas concentration on the wafer 200 at the start of the HCDS gas supply can be suppressed. As a result, the in-plane thickness distribution of the first layer formed in step A1 can be stably and reproducibly controlled. As described above, the in-plane thickness distribution at the initial stage of the formation of the first layer can be a major factor determining the final in-plane thickness distribution of the first layer. Therefore, the above-mentioned effect enables stable and reproducible control of the in-plane thickness distribution of the SiN film formed on the wafer 200.

[0172] (f) By arranging nozzles 249b and 249c on both sides of nozzle 249a, the controllability of the in-plane thickness distribution of the first layer, i.e. the controllability of the in-plane thickness distribution of the SiN film formed on wafer 200, can be improved.

[0173] (g) By arranging the nozzles 249a to 249c respectively in a manner opposite to the exhaust port 231a, the controllability of the in-plane thickness distribution of the first layer, that is, the controllability of the in-plane thickness distribution of the SiN film formed on the wafer 200, can be improved.

[0174] (h) The same effect can be obtained when using raw materials other than HCDS gas, reactants other than NH3 gas, or inactive gases other than N2 gas.

[0175] (4) Variations

[0176] The film-forming steps in this embodiment are not limited to... Figure 4 The method shown can be modified as illustrated in the following variations. Furthermore, these variations can be combined arbitrarily. It should be noted that, unless otherwise specified, the processing steps and conditions in each variation are the same as those in each step of the substrate processing sequence described above.

[0177] (Variation Example 1)

[0178] exist Figure 4In the film formation sequence shown, step A1 is described using an example where the supply of N2 gas from nozzle 249a begins before the supply of HCDS gas. However, the supply of N2 gas from nozzle 249a and the supply of HCDS gas can also begin simultaneously. In this case, using... Figure 4 The film-forming sequence shown can also shorten the processing time of each cycle and improve the productivity of film-forming processes.

[0179] However, in this case, the following situation exists: the concentration of HCDS gas within the plane of wafer 200 changes excessively at the start of HCDS gas supply, thereby affecting the in-plane thickness distribution of the first layer. Therefore, in order to stably and reproducibly control the in-plane thickness distribution of the first layer formed on wafer 200 during period T1, such as Figure 4 As shown, preferably, in step A1, the supply of N2 gas from nozzle 249a is started before the supply of HCDS gas.

[0180] (Variation Example 2)

[0181] exist Figure 4 In the film-forming sequence shown, an example where the fourth flow rate is equal to the second flow rate in step A2 (fourth flow rate = second flow rate) is illustrated, but the fourth flow rate can also be less than the second flow rate (fourth flow rate < second flow rate). Alternatively, the fourth flow rate can be zero, and the supply of N2 gas from nozzles 249b and 249c can be stopped. Or, the fourth flow rate can be greater than the second flow rate (fourth flow rate > second flow rate).

[0182] In step A2, when the fourth flow rate is less than the second flow rate, the in-plane thickness distribution of the SiN film formed on the wafer 200 can be finely adjusted, for example, in a direction that reduces the central convexity distribution. Furthermore, in step A2, when the fourth flow rate is zero, the in-plane thickness distribution of the SiN film formed on the wafer 200 can be finely adjusted, for example, in a direction that further reduces the central convexity distribution. Additionally, in step A2, when the fourth flow rate is greater than the second flow rate, the in-plane thickness distribution of the SiN film formed on the wafer 200 can be finely adjusted, for example, in a direction that strengthens the central convexity distribution.

[0183] As described above, by adjusting the magnitude of the fourth flow rate in step A2, the in-plane thickness distribution of the SiN film formed on the wafer 200 can be finely adjusted.

[0184] (Variation Example 3)

[0185] exist Figure 4In the film formation sequence shown, step A2 illustrates an example of stopping the supply of N2 gas from nozzle 249a. However, as mentioned above, HCDS gas can also be supplied simultaneously with the supply of N2 gas from nozzle 249a at a third flow rate that is smaller than both the first and second flow rates but greater than zero. This allows for fine-tuning of the in-plane thickness distribution of the SiN film formed on wafer 200, for example, towards a direction that enhances the central convexity distribution.

[0186] (Variation Example 4)

[0187] As raw materials, alkyl halosilane raw material gases such as 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH3)2Si2Cl4, abbreviated as TCDMDS) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H, abbreviated as 3DMAS) gas, and bis(diethylamino)silane (SiH2[N(C2H5)2]2, abbreviated as BDEAS) gas can also be used.

[0188] In addition, amine gases such as triethylamine ((C2H5)3N, abbreviated as TEA) gas, oxygen (O2) gas, water vapor (H2O) gas, ozone (O3) gas, and plasma-activated O2 gas can also be used as reactants. ＊ O2 gas + hydrogen (H2) gas (oxidizing agent), propylene (C3H6) gas (carbon-containing gas), trichloroborane (BCl3) gas (b-containing gas)

[0189] Alternatively, silicon oxide nitride (SiON) film, silicon oxide carbon nitride (SiOCN) film, silicon oxide carbon nitride (SiOC) film, silicon carbon nitride (SiCN) film, silicon boron carbon nitride (SiBCN) film, silicon boron nitride (SiBN) film, and silicon oxide (SiO) film can be formed on wafer 200 using, for example, the following film formation sequence.

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[0199] In the above film-forming sequence, when the raw material is supplied, it is through a process of... Figure 4 Performing steps A1 and A2 in the same manner as the shown film-forming sequence and the modified examples described above will also yield the same results. It should be noted that the processing steps and conditions for supplying raw materials and reactants can be set as described above. Figure 4 The film formation sequence shown is the same as in the above variations.

[0200] <Other Implementation Methods>

[0201] The embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from its spirit.

[0202] In the above embodiment, an example was described where the second supply section has nozzles 249b and 249c, which are arranged on both sides of the nozzle 249a serving as the first supply section. However, the present invention is not limited to this embodiment. For example, the second supply section may be configured to have only nozzle 249b, with nozzle 249b either close to or away from nozzle 249a. In this case, when raw materials are supplied, the material is fed through... Figure 4 The film formation sequence shown, and the steps A1 and A2 of the above-described modifications, can also achieve the same effect. However, the nozzle configuration in the above embodiment is more preferable in terms of improving the controllability of the in-plane film thickness distribution of the film formed on the wafer 200.

[0203] In the above embodiments, examples of performing steps A1 and A2 during raw material supply have been described, but the present invention is not limited to the above methods. For example, steps A1 and A2 may be performed during reactant supply instead of during HCDS gas supply. In this case, it is also possible to control the concentration distribution of N, C, O, B, etc., within the surface of the film formed on the wafer 200. Steps A1 and A2 performed during reactant supply can utilize... Figure 4 The film formation sequence shown is the same as the processing conditions and processing steps shown in steps A1 and A2 in the above variations.

[0204] In the above embodiment, an example of supplying reactants such as NH3 gas from nozzle 249b has been described, but the present invention is not limited to this method. For example, reactants may be supplied from both nozzles 249b and 249c. Alternatively, a nozzle different from nozzles 249a to 249c may be newly installed in the processing chamber 201, and the reactants may be supplied using this newly installed nozzle. In the above cases, when the raw materials are supplied, it is also possible to... Figure 4 The film-forming sequence shown is performed in the same manner as the above-mentioned modified examples, following steps A1 and A2, and achieving the same effect.

[0205] In the above embodiments, an example of forming a film containing Si as the main element on a substrate has been described, but the present invention is not limited to the above-described manner. That is, in addition to Si, the present invention can also be suitably applied to the case of forming films on a substrate containing half-metallic elements such as germanium (Ge) and boron (B) as the main elements. In addition, the present invention can also be suitably applied to the case of forming films on a substrate containing metallic elements such as titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), yttrium (Y), lanthanum (La), strontium (Sr), and aluminum (Al) as the main elements.

[0206] For example, the present invention can also be suitably applied to the formation of titanium nitride films (TiN films), titanium oxynitride films (TiON films), titanium aluminum carbon nitride films (TiAlCN films), titanium aluminum carbide films (TiAlC films), titanium carbon nitride films (TiCN films), and titanium oxide films (TiO films) on a substrate by using titanium tetrachloride (TiCl4) gas and trimethylaluminum (Al(CH3)3, abbreviated as TMA) gas as raw materials, in the following film formation sequence.

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[0212]

[0213] Preferably, the substrate processing steps are prepared individually according to the processing requirements and pre-stored in the storage device 121c via an electrical communication line and an external storage device 123. Furthermore, preferably, at the start of processing, the CPU 121a appropriately selects a suitable process from among the multiple processes stored in the storage device 121c according to the processing requirements. This allows for the reproducible formation of films of various types, compositions, qualities, and thicknesses using a single substrate processing apparatus. In addition, it reduces operator workload, avoids operational errors, and enables rapid commencement of substrate processing.

[0214] The aforementioned process is not limited to the case of new fabrication. For example, it can also be prepared by changing an existing process already installed in the substrate processing apparatus. In the case of changing the process, the changed process can also be installed in the substrate processing apparatus via an electrical communication line and a recording medium containing the process. Furthermore, the existing process already installed in the substrate processing apparatus can be directly changed by operating the input / output device 122 of the existing substrate processing apparatus.

[0215] In the above embodiments, an example was described where the first and second supply units are arranged along the inner wall of the reaction tube within the processing chamber. However, the present invention is not limited to the above embodiments. For example, as... Figure 6 As shown in the cross-sectional structure of the vertical processing furnace in (a), a buffer chamber can also be provided on the side wall of the reaction tube, and the first and second supply sections configured in the same way as in the above embodiment can be provided in the buffer chamber. Figure 6 In (a), an example is shown where a supply buffer chamber and an exhaust buffer chamber are provided on the sidewall of the reaction tube, and they are respectively arranged in opposite positions while the wafer is sandwiched between them. It should be noted that the supply buffer chamber and the exhaust buffer chamber are respectively provided from the lower part of the sidewall of the reaction tube along the upper part, that is, along the wafer arrangement area. Furthermore, in Figure 6 In (a), an example is shown where the supply buffer chamber is divided into multiple (three) spaces, and each nozzle is arranged in each space. The arrangement of the three spaces in the buffer chamber is the same as that of the first and second supply sections. Additionally, for example, as... Figure 6 As shown in the cross-sectional structure of the vertical processing furnace in (b), it can also be connected with... Figure 6 (a) A buffer chamber is configured in the same way, with a first supply unit installed inside the buffer chamber, and a second supply unit installed along the inner wall of the reaction tube, flanking the connecting portion of the buffer chamber that communicates with the processing chamber from both sides. It should be noted that... Figure 6 (a) Figure 6 The components other than the buffer chamber and reaction tube described in (b) are the same as those in the description. Figure 1 The configuration of each part of the processing furnace shown is the same. When using these processing furnaces, the same effects as in the above-described embodiments can be obtained.

[0216] In the above embodiments, an example of forming a film using a batch substrate processing apparatus (processing multiple substrates at a time) has been described. However, the present invention is not limited to the above embodiments. For example, it is also preferably applicable to the case of forming a film using a monolithic substrate processing apparatus (processing one or more substrates at a time). Furthermore, in the above embodiments, an example of forming a film using a substrate processing apparatus with a hot-wall type processing furnace has been described. The present invention is not limited to the above embodiments, and it is also preferably applicable to the case of forming a film using a substrate processing apparatus with a cold-wall type processing furnace.

[0217] When using these substrate processing apparatuses, film formation can be performed in the same order and under the same processing conditions as the above-described embodiments and variations, and the same effects can be obtained.

[0218] Furthermore, the above-described embodiments and variations can be used in appropriate combinations. The processing steps and conditions can then be set to be, for example, the same as those in the above-described embodiments.

[0219] SiN films formed by the methods described above, including variations, can be widely used as insulating films, isolation films, masks, charge storage films, stress control films, etc. In recent years, with the miniaturization of semiconductor devices, the uniformity of in-plane film thickness on films formed on wafers has become increasingly stringent. This invention enables the formation of films with a flat distribution on patterned wafers with high-density patterns on their surfaces, and is therefore highly advantageous as a technology capable of meeting such requirements.

[0220] Example

[0221] The following describes the experimental results that support the effects obtained by the above-described embodiments.

[0222] As examples 1 to 3, using Figure 1 The substrate processing apparatus shown utilizes Figure 4 The film formation sequence shown involves forming SiN films on multiple wafers. In Examples 1-3, in step A1, the flow rate (first flow rate) of N2 gas supplied from one nozzle serving as the first supply unit is set to 10 slm, and the total flow rate (second flow rate) of N2 gas supplied from the two nozzles serving as the second supply unit is sequentially set to 1 slm (0.5 slm × 2), 4 slm (2 slm × 2), and 10 slm (5 slm × 2). Furthermore, in step A2, the supply of N2 gas from one nozzle serving as the first supply unit is stopped, and the total flow rate (fourth flow rate) of N2 gas supplied from the two nozzles serving as the second supply unit is set to the same flow rate as the second flow rate. Other processing conditions are set to the specified conditions within the range of processing conditions described in the above embodiments.

[0223] As comparative examples 1-3, using Figure 1 The substrate processing apparatus shown performs a predetermined number of cycles of supplying HCDS gas to the wafer and supplying NH3 gas to the wafer separately, thereby forming SiN films on multiple wafers. In the comparative examples described above, steps A1 and A2 are not performed, and the supply of N2 gas from the first supply unit and the second supply unit is controlled as follows: In Comparative Examples 1 and 2, during the step of supplying HCDS gas to the wafer, the supply of N2 gas from one nozzle serving as the first supply unit is stopped, and the total flow rate of N2 gas supplied from the two nozzles serving as the second supply unit is sequentially set to 0.2 slm (0.1 slm × 2) and 10 slm (5 slm × 2). In Comparative Example 3, during the step of supplying HCDS gas to the wafer, the flow rate of N2 gas supplied from one nozzle serving as the first supply unit is set to 10 slm, and the total flow rate of N2 gas supplied from the two nozzles serving as the second supply unit is set to 0.2 slm (0.1 slm × 2). Other processing conditions are set to be the same as those in the embodiments.

[0224] In addition, the in-plane thickness distribution of the SiN films in Examples 1-3 and Comparative Examples 1-3 was measured respectively. Figure 7 (a) Figure 7 The results of their measurements are shown in (b). Figure 7 (a) Figure 7 (b) The vertical axis represents the ratio of the SiN film thickness at the measurement location to the SiN film thickness at the outer periphery of the wafer (film thickness at the measurement location / film thickness at the outer periphery of the wafer). Figure 7 (a) Figure 7 (b) The horizontal axis represents the distance [mm] from the measurement position to the center of the wafer. Figure 7 In (a), the ◆, ■, and ▲ markings represent the measurement results of Examples 1 to 3, respectively. Figure 7 (b) The ◆, ■, and ▲ markings indicate the measurement results of Comparative Examples 1 to 3, respectively.

[0225] Depend on Figure 7 (a) It can be seen that the in-plane thickness distribution of the SiN film in Example 3 exhibits a strong central convex distribution, and the degree of central convex distribution decreases in the order of Examples 2 and 1. That is, it can be seen that in step A1, by setting the first flow rate to a large flow rate and adjusting the second flow rate between a large flow rate and a small flow rate, the degree of central convex distribution of the in-plane thickness distribution of the SiN film formed on the wafer can be strengthened or weakened, and the in-plane thickness distribution can be controlled within a wide range.

[0226] according to Figure 7(b) It can be seen that the in-plane thickness distribution of the SiN films in Comparative Examples 1 to 3 does not show a centrally convex distribution, but rather shows a tendency to become thickest at the outer periphery. In addition, in some comparative examples, the degree of central concave distribution becomes very strong. It can be seen that in the film deposition methods used in Comparative Examples 1 to 3, it is difficult to control the in-plane thickness distribution of the SiN films formed on the wafer to be, for example, a flat distribution or a centrally convex distribution.

Claims

1. A substrate processing method comprising a step of forming a film on a substrate by performing a predetermined number of cycles including the following steps (a) and (b): Process (a), supplying raw materials to the substrate; Step (b) involves supplying a reactant to the substrate. In process (a), the following processes (a-1) and (a-2) are performed sequentially: In step (a-1), the substrate is supplied with an inactive gas at a first flow rate from a first supply unit and the raw material is supplied simultaneously, and an inactive gas is supplied at a second flow rate from a second supply unit different from the first supply unit. In step (a-2), for the substrate, an inert gas is supplied from the first supply unit at a third flow rate lower than the first flow rate, and the raw material is supplied simultaneously; and an inert gas is supplied from the second supply unit at a fourth flow rate; or, for the substrate, while the supply of inert gas from the first supply unit is stopped, the raw material is supplied from the first supply unit, and an inert gas is supplied from the second supply unit at a fourth flow rate. Specifically, the second flow rate and the fourth flow rate are each different from the third flow rate.

2. The substrate processing method according to claim 1, wherein, Make the implementation time of process (a-1) shorter than that of process (a-2).

3. The substrate processing method according to claim 1, wherein, Make the partial pressure of the raw material in step (a-1) less than the partial pressure of the raw material in step (a-2).

4. The substrate processing method according to claim 1, wherein, While ensuring that the supply flow rate of the raw material in step (a) is less than the first flow rate, the partial pressure of the raw material in step (a-1) is less than the partial pressure of the raw material in step (a-2).

5. The substrate processing method according to claim 1, wherein, Process (a-1) is carried out while the adsorption state of the main elements constituting the membrane contained in the raw material is in a pseudo-unsaturated state.

6. The substrate processing method according to claim 1, wherein, Step (a-2) is performed while the adsorption state of the main elements constituting the membrane contained in the raw material is in a pseudo-saturated state.

7. The substrate processing method according to claim 1, wherein, In step (a), a first layer is formed, and step (a-1) is performed during the period when the formation rate of the first layer changes from a first rate to a second rate that is smaller than the first rate.

8. The substrate processing method according to claim 1, wherein, In step (a), a first layer is formed, and step (a-2) is performed during the period after the formation rate of the first layer changes from a first rate to a second rate that is smaller than the first rate.

9. The substrate processing method according to claim 1, wherein, The amount of raw material reaching the center of the substrate in step (a-1) is greater than the amount of raw material reaching the center of the substrate in step (a-2).

10. The substrate processing method according to claim 1, wherein, In step (a-1), the amount of the raw material reaching the center of the substrate is greater than the amount of the raw material reaching the outer periphery of the substrate.

11. The substrate processing method according to claim 1, wherein, The concentration of the raw material at the center of the substrate in step (a-1) is higher than the concentration of the raw material at the center of the substrate in step (a-2).

12. The substrate processing method according to claim 1, wherein, In process (a-1), the concentration of the raw material at the central portion of the substrate is higher than the concentration of the raw material at the outer periphery of the substrate.

13. The substrate processing method according to claim 1, wherein, By adjusting the fourth flow rate, the film thickness distribution of the film formed on the substrate within the plane of the substrate can be finely adjusted.

14. The substrate processing method according to claim 1, wherein, In process (a-1), the supply of inactive gas from the first supply unit is initiated before the supply of the raw material.

15. The substrate processing method according to claim 1, wherein, The second supply unit has a plurality of supply units, which are arranged on both sides of the first supply unit, sandwiching the first supply unit.

16. The substrate processing method according to claim 1, wherein, The first flow rate and the second flow rate are each greater than the supply flow rate of the raw material in step (a-1).

17. The substrate processing method according to claim 1, wherein, The fourth flow rate is made greater than the supply flow rate of the raw material in step (a-2).

18. The substrate processing method according to claim 1, wherein, The third flow rate is made less than the supply flow rate of the raw material in process (a-2).

19. The substrate processing method according to claim 1, wherein, In step (a-2), the supply of inactive gas from the first supply unit is stopped, so that the third flow rate is zero.

20. The substrate processing method according to claim 1, wherein, Make the third flow rate less than the second flow rate.

21. The substrate processing method according to claim 1, wherein, Make the second flow rate different from the first flow rate.

22. A method for manufacturing a semiconductor device, comprising a step of forming a film on a substrate by performing a cycle comprising steps (a) and (b) a predetermined number of times: Process (a), supplying raw materials to the substrate; Step (b) involves supplying a reactant to the substrate. In process (a), the following processes (a-1) and (a-2) are performed sequentially: In step (a-1), the substrate is supplied with an inactive gas at a first flow rate from a first supply unit and the raw material is supplied simultaneously, and an inactive gas is supplied at a second flow rate from a second supply unit different from the first supply unit. In step (a-2), for the substrate, an inert gas is supplied from the first supply unit at a third flow rate lower than the first flow rate, and the raw material is supplied simultaneously; and an inert gas is supplied from the second supply unit at a fourth flow rate; or, for the substrate, while the supply of inert gas from the first supply unit is stopped, the raw material is supplied from the first supply unit, and an inert gas is supplied from the second supply unit at a fourth flow rate. Specifically, the second flow rate and the fourth flow rate are each different from the third flow rate.

23. A substrate processing apparatus, comprising: A raw material supply system for supplying raw materials to a substrate; A reactant supply system for supplying reactants to a substrate; An inactive gas supply system for supplying inactive gas to a substrate; and The control unit is configured to control the raw material supply system, the reactant supply system, and the inactive gas supply system in a manner that allows for the formation of a film on the substrate by performing a process comprising repeating the following processes (a) and (b) a predetermined number of times: Process (a), supplying the raw material to the substrate; Process (b), supplying the reactant to the substrate, in, In process (a), the following processes (a-1) and (a-2) are performed sequentially: Process (a-1): For the substrate, the raw material is supplied simultaneously with the inactive gas supplied from the first supply section at a first flow rate, and the inactive gas is supplied from the second supply section, which is different from the first supply section, at a second flow rate. Process (a-2): For the substrate, an inactive gas is supplied from the first supply unit at a third flow rate smaller than the first flow rate, and the raw material is supplied simultaneously; and an inactive gas is supplied from the second supply unit at a fourth flow rate; or, for the substrate, the raw material is supplied from the first supply unit while the supply of inactive gas from the first supply unit is stopped, and an inactive gas is supplied from the second supply unit at a fourth flow rate, wherein the second flow rate and the fourth flow rate are each different from the third flow rate.

24. A computer-readable recording medium containing a program that enables a substrate processing apparatus to perform the following steps via a computer: The steps of forming a film on a substrate by repeating the following steps (a) and (b) a predetermined number of times: Step (a): Supply raw materials to the substrate; Step (b): The substrate is supplied with a reactant; In step (a), the following steps (a-1) and (a-2) are performed sequentially: Step (a-1) involves supplying the substrate with the raw material while simultaneously supplying the inactive gas from the first supply unit at a first flow rate, and supplying the inactive gas from a second supply unit different from the first supply unit at a second flow rate. Step (a-2): For the substrate, an inactive gas is supplied from the first supply section at a third flow rate smaller than the first flow rate, and the raw material is supplied simultaneously, while an inactive gas is supplied from the second supply section at a fourth flow rate; or, for the substrate, the raw material is supplied from the first supply section while the supply of inactive gas from the first supply section is stopped, and an inactive gas is supplied from the second supply section at a fourth flow rate. The steps of making the second flow and the fourth flow different from the third flow.

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