Substrate processing method, semiconductor device manufacturing method, substrate processing apparatus and program

Abstract

Provided is technology that makes it possible to improve film thickness uniformity and burying properties in the formation of a film. In the present invention, a cycle in which the following steps are executed in the following order on a substrate is repeated a prescribed number of times: (a) a step for supplying a first reforming gas, which is an inorganic halogen-element-containing gas; (b) a step for supplying a raw-material gas; (c) a step for supplying a second reforming gas, which is an inorganic halogen-element-containing gas; and (d) a step for supplying a reactant gas.

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing method, a semiconductor device manufacturing method, a substrate processing apparatus, and a program. [Background technology]

[0002] BACKGROUND ART In recent years, with the miniaturization and increasing complexity of device geometries in LSI manufacturing processes, higher step coverage and high embedding characteristics are required in film formation (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-69407 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can improve the uniformity of film thickness and filling characteristics in film formation.

[0005] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a substrate is provided with: (a) One of the following: hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas The first reformed gas is supplied. The first modifying gas is adsorbed onto a portion of the substrate. process and (b) The first modifying gas contains metal elements and halogen elements, and its adsorption is inhibited by the first modifying gas adsorbed on the substrate. Supply raw gas The source gas is then adsorbed onto another part of the substrate, forming an adsorption layer of the source gas molecules. and (c) One of the following: hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas The second reformed gas is supplied. and reacting a part of the adsorption layer with the second reformed gas. process and (d) Nitrogen-containing gas or reducing gas Reaction gas supply and then a substitution reaction is caused between the other part of the adsorption layer and the reaction gas. A technique is provided in which a cycle of performing the steps (a) and (b) in the order is performed a predetermined number of times. [Effects of the Invention]

[0007] According to the present disclosure, in forming a film, it is possible to improve the uniformity of the film thickness and the filling characteristics. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic longitudinal sectional view of a vertical processing furnace of a substrate processing apparatus according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic configuration diagram of a controller of a substrate processing apparatus according to an embodiment of the present disclosure, and is a block diagram showing a control system of the controller. [Figure 3] FIG. 3 is a diagram illustrating a substrate processing method according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram showing the supply amounts of each gas in a film formation sequence according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram illustrating the progress of the substrate processing method of FIG. [Figure 6] FIG. 6 is a diagram showing the partial pressures of each gas in a film formation sequence according to one embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram showing a film formation sequence according to the first modified example. [Figure 8] FIG. 8 is a diagram showing a film formation sequence according to the second modified example. [Figure 9] FIG. 9 is a diagram showing a film formation sequence according to the third modified example. [Figure 10] FIG. 10 is a diagram showing a film formation sequence according to the fourth modified example. [Figure 11] FIG. 11 is a diagram showing a film formation sequence according to the fifth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following description will be made using the drawings. However, in the following description, the same components are given the same reference numerals, and repeated description may be omitted. Note that the drawings may be depicted more schematically than the actual embodiment to make the description clearer, but they are merely examples and do not limit the interpretation of the present invention. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships and ratios of each element shown in the drawings may not necessarily match those of the actual embodiment. Furthermore, the dimensional relationships and ratios of each element may not necessarily match between multiple drawings.

[0010] Preferred embodiments of the present disclosure will be described below with reference to the drawings. A substrate processing apparatus 10 is configured as an example of an apparatus used in a substrate processing process, which is one step in the manufacturing process of a semiconductor device. First, the substrate processing apparatus used in the embodiment will be described. Specifically, this substrate processing apparatus is a semiconductor device manufacturing apparatus, and is used in one step in the manufacturing process of a semiconductor device. In the following description, a configuration using a substrate processing apparatus that performs film formation processing, etc. on multiple substrates (wafers) at once will be described as an example of a substrate processing apparatus.

[0011] (1) Configuration of the substrate processing equipment 1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus according to the present disclosure, showing a vertical cross-sectional view of the processing furnace portion. As shown in FIG. 1, the processing furnace 202 has a heater 207 as a heating mechanism (temperature adjustment unit). The heater 207 is cylindrical and is installed vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gases with heat.

[0012] A reaction tube 203 is disposed 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 has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed 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 has a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is installed vertically, similar to the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates. In the processing chamber 201, processing of the wafers 200 is performed.

[0013] Nozzles 249a to 249e serving as first to fifth supply units are provided in the processing chamber 201, respectively, so as to penetrate the sidewall of the manifold 209. In FIG. 1, three nozzles, 249a to 249c, are depicted, and two nozzles, 249d to 249e, are omitted from the drawing to avoid complicating the illustration. The nozzles 249a to 249e are also referred to as first to fifth nozzles. The nozzles 249a to 249e are made of a heat-resistant material such as quartz or SiC. The nozzles 249a to 249e are connected to gas supply pipes 232a to 232e, respectively. The nozzles 249a to 249e are different nozzles.

[0014] The gas supply pipes 232a to 232e are respectively provided with mass flow controllers (MFCs) 241a to 241e, which are flow rate control devices (flow rate control parts), and valves 243a to 243e, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipes 232f to 232j are respectively connected to the gas supply pipes 232a to 232e downstream of the valves 243a to 243e. Gas supply pipes The gas supply pipes 232f to 232j are respectively provided with MFCs 241f to 241j and valves 243f to 243j in order from the upstream side of the gas flow. The gas supply pipes 232a to 232j are made of a metal material, for example, SUS or the like.

[0015] The nozzles 249a to 249e are provided in a circular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, extending from the bottom to the top of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249e are provided in a region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region where the wafers 200 are arranged, and extending along the wafer arrangement region. Gas supply holes 250a to 250d for supplying gas are provided on the side surfaces of the nozzles 249a to 249e, respectively. Each of the gas supply holes 250a to 250d opens to face (face) the exhaust port 231a in a plan view, enabling gas to be supplied toward the wafers 200. A plurality of gas supply holes 250a to 250d are provided from the bottom to the top of the reaction tube 203.

[0016] From the gas supply pipe 232a, a raw material gas is supplied as a processing gas into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a. As the raw material gas, for example, a halogen-containing gas (halogen-based gas) containing a halogen element, such as a gas containing a metal element (metal-containing gas), can be used. Here, examples of halogen elements include fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). As the halogen-containing gas, for example, a chloride gas containing Cl is used. In this specification, the term "raw material" may mean a "liquid raw material in a liquid state," a "raw material gas in a gaseous state," or both.

[0017] A first modifying gas (also referred to as a first film formation inhibiting gas or a first inhibitor), which is an inorganic halogen element-containing gas, is supplied from the gas supply pipe 232b through the MFC 241b, the valve 243b, and the nozzle 249b into the processing chamber 201. As the first modifying gas, for example, a halogen element-containing gas, such as a hydrogen halide gas, can be used.

[0018] A reactive gas serving as a processing gas is supplied from the gas supply pipe 232c through the MFC 241c, the valve 243c, and the nozzle 249c into the processing chamber 201. As the reactive gas, for example, a nitrogen (N)-containing gas (nitriding gas, nitriding agent) can be used.

[0019] A second modifying gas (also referred to as a second film formation inhibiting gas or a second inhibitor), which is an inorganic halogen element-containing gas, is supplied from the gas supply pipe 232d through the MFC 241d, the valve 243d, and the nozzle 249d into the processing chamber 201. As the second modifying gas, for example, a halogen element-containing gas, such as a hydrogen halide gas, can be used.

[0020] An etching gas is supplied from the gas supply pipe 232e into the processing chamber 201 via the MFC 241e, the valve 243e, and the nozzle 249e.

[0021] From the gas supply pipes 232f to 232j, an inert gas such as nitrogen (N2) gas is supplied into the processing chamber 201 via the MFCs 241f to 241j, the valves 243f to 243j, and the nozzles 249a to 249e, respectively. The N2 gas acts as a purge gas, a carrier gas, a dilution gas, etc.

[0022] The raw material gas is supplied mainly through the gas supply pipe 232a, the MFC 241a, and the valve 243a. vinegar A supply system is constituted. A first modifying gas supply system is mainly constituted by the gas supply pipe 232b, the MFC 241b, and the valve 243b. A reactive gas supply system is mainly constituted by the gas supply pipe 232c, the MFC 241c, and the valve 243c. A second modifying gas supply system is mainly constituted by the gas supply pipe 232d, the MFC 241d, and the valve 243d. An etching gas supply system is mainly constituted by the gas supply pipe 232e, the MFC 241e, and the valve 243e. An inert gas supply system is mainly constituted by the gas supply pipes 232f to 232j, the MFCs 241f to 241j, and the valves 243f to 243j.

[0023] The first modifying gas and the second modifying gas may be the same modifying gas. In this case, the nozzle 249d of the second modifying gas supply system is not used, and only the nozzle 249b of the first modifying gas supply system is used to supply the first modifying gas and the second modifying gas into the processing chamber 201. When this configuration is adopted, the second modifying gas supply system (gas supply pipe 232d, MFC 241d, valve 243d) and the inert gas supply system including the gas supply pipe 232i, MFC 241i, and valve 243i can be eliminated from the substrate processing apparatus shown in FIG. 1, thereby simplifying the configuration of the substrate processing apparatus.

[0024] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which the valves 243a to 243j, the MFCs 241a to 241j, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232j, and is configured such that the supply operation of various gases into the gas supply pipes 232a to 232j, i.e., the opening and closing operation of the valves 243a to 243j and the flow rate adjustment operation by the MFCs 241a to 241j, are controlled by a controller 121, which will be described later.

[0025] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. The exhaust port 231a is provided at a position facing (opposite) the nozzles 249a to 249e (gas supply holes 250a to 250e) across the wafer 200. The exhaust port 231a may be provided along the sidewall of the reaction tube 203 from the bottom to the top, i.e., along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 is configured to be able to evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating, and further, to be able to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be considered to be included in the exhaust system.

[0026] Below the manifold 209, a seal cap 219 is provided as a furnace port cover that can airtightly close the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that abuts against the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 that rotates the boat 217 (described later) is provided. A rotation shaft 255 of the rotation mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200.

[0027] The seal cap 219 is configured to be raised and lowered vertically by a boat elevator 115 serving as an elevating mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that raises and lowers the seal cap 219 to load and unload (transport) the wafers 200 into and out of the process chamber 201. A shutter 219s serving as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is unloaded from the process chamber 201 is provided below the manifold 209. The shutter 219s is made of a metal material such as SUS and has a disk shape. An O-ring 220c serving as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the shutter 219s. The opening and closing operation (lifting and rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0028] The boat 217, serving as a substrate support, is configured to support multiple wafers (e.g., 25 to 200 wafers) 200 in a horizontal position, aligned vertically with their centers aligned, and arranged in multiple stages, i.e., spaced apart. The boat 217 is made of a heat-resistant material such as quartz or SiC. Thermal insulation plates 218, also made of a heat-resistant material such as quartz or SiC, are supported in multiple stages below the boat 217. Note that, in this specification, a numerical range such as 25 to 200 wafers means 25 to 200 wafers. This also applies to the number of objects, as well as all numerical values ​​described herein, such as pressure, flow rate, time, and temperature.

[0029] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can be adjusted to a desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0030] 2, controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, storage device 121c, and I / O port 121d. RAM 121b, storage device 121c, and I / O port 121d are configured to be able to exchange data with CPU 121a via internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to controller 121.

[0031] The storage device 121c is configured with, for example, a flash memory, an HDD (Hard Disk Drive), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for substrate processing (described later), etc., are readably stored in the storage device 121c. A process recipe is a combination of procedures for substrate processing (described later) that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, process recipes, control programs, etc. are collectively referred to simply as programs. A process recipe is also simply referred to as a recipe. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0032] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241j, valves 243a to 243j, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, and the like.

[0033] The CPU 121a is configured to read and execute a control program from the storage device 121c, and also to read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241j, the opening and closing operations of the valves 243a to 243j, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, and the like.

[0034] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0035] (2) Substrate processing process Fig. 3 is a diagram illustrating a substrate processing method according to an embodiment of the present disclosure. Figs. 4 and 6 are diagrams illustrating a film formation sequence according to an embodiment of the present disclosure. Fig. 5 is a diagram illustrating the progress of the substrate processing method.

[0036] As one step in a method for manufacturing a semiconductor device (substrate processing method), an example of a step of forming a film on a substrate (wafer) having a trench (groove, recess, or barrel-shaped recess) formed on its surface will be described with reference to FIGS. 3 to 6. The step of forming the film is carried out in the processing chamber 201 of the substrate processing apparatus shown in FIG. 1. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121 shown in FIG. 2.

[0037] A preferred film formation sequence (also simply referred to as a sequence) of this embodiment is as follows: (a) supplying a first modifying gas which is an inorganic halogen-containing gas; (b) supplying a raw material gas; (c) supplying a second modifying gas which is an inorganic halogen-containing gas; (d) supplying a reactive gas; The cycle of executing the above steps in the order is repeated a predetermined number of times. The order is (a) -> (b) -> (c) -> (d).

[0038] In this embodiment, the following gases are used, for example: The first modifying gas and the second modifying gas are inorganic halogen-containing gases, such as hydrogenated halogen gas; the source gas is a gas containing a metal element as the first element; and the reactive gas is, for example, an N-containing gas.

[0039] Specifically, as shown in FIG. 4, the film formation sequence involves repeating a cycle of flowing a first modifying gas, a raw material gas containing a first element, a second modifying gas, and a reactive gas in a time-division manner a predetermined number of times (n times) to form a film containing a first element (also simply referred to as a film).

[0040] 5, there are some areas on the surface of the substrate (wafer) 200 that are easy to reach with the gas for forming a thin film and some areas that are difficult to reach with the gas. An example of an area that is easy to reach with the gas is the upper portion 301 of a recessed portion (or a barrel-shaped recessed portion, trench) 300 with a high aspect ratio. An example of an area that is difficult to reach with the gas is the bottom (deep portion) 302 of the recessed portion 300 with a high aspect ratio.

[0041] As shown in FIG. 3, the substrate processing method includes the following steps (a), (b), (P1), (c), (d), and (P2) as a film formation sequence. (a) First reforming gas supply step (first reaction-inhibiting gas supply step) (b) Source gas supply step (halogen-based source gas supply) (P1) First residual gas removal step (c) Second reforming gas supply step (second reaction inhibitor gas supply step) (d) Reaction gas supply step (N-containing gas supply step) (P2) Residual gas removal step This cycle of executing (a), (b), (P1), (c), (d), and (P2) in this order is repeated a predetermined number of times. For example, the predetermined number of times is set to n times (n is an integer equal to or greater than 1).

[0042] As shown in FIG. 3, an etching step (e) of etching the formed film may then be performed as an etching sequence. 。 Thereafter, a film is formed by repeating a cycle of performing the film formation sequence and the etching sequence a predetermined number of times. In this case, the predetermined number is L times, where L is an integer equal to or greater than 0. Here, L=0 means that the etching step (e) is not performed. That is, in the substrate processing method shown in FIG. 3, a cycle of performing (a), (b), (P1), (c), (d), and (P2) in this order may be performed a predetermined number of times without performing (e).

[0043] 5 is a diagram illustrating the progress of a substrate processing method. Here, an example is described in which a film 400 is embedded inside a barrel-shaped recess 300 formed on the surface of a substrate (wafer) 200. The top 301 of the recess 300 can be considered to be a location where gas can easily reach, and the bottom 302 of the recess 300 can be considered to be a location where gas cannot easily reach.

[0044] In the initial cycle of film formation, a film formation sequence is performed n times to form a thin film 400 on the inner wall of the barrel-shaped recess 300. Then, an etching sequence is performed to remove the film 400 from the upper part 301 of the recess 300 by etching. This widens the opening of the upper part 301 of the recess 300, making it easier for gas to reach the inside of the recess 300.

[0045] When the cycle of performing the film formation sequence and the etching sequence is performed multiple times, the inside of the recess 300 is gradually filled with the film 400, as shown in State A in Fig. 5. Finally, the inside of the recess 300 is completely filled with the film 400, as shown in State B.

[0046] In this specification, "performing a process (also referred to as a process, cycle, step, etc.) a predetermined number of times" means performing the process once or multiple times. In other words, performing the process one or more times. FIG. 5 shows an example in which each process in the film formation sequence is repeated n cycles, and an example in which each process in the film formation sequence and the etching sequence is repeated L cycles. The values ​​of n and L are appropriately selected depending on the film thickness required for the final film to be formed. In other words, the number of times each of the above processes is performed is determined depending on the target film thickness.

[0047] In this specification, "time-division" means being separated in time. For example, in this specification, performing each process in a time-division manner means performing each process asynchronously, i.e., without synchronization. In other words, it means performing each process intermittently (in pulses). In other words, it means that the process gases supplied in each process are supplied so as not to mix with each other. When each process is performed multiple times in a time-division manner, the process gases supplied in each process are supplied alternately so as not to mix with each other.

[0048] In this specification, the term "wafer" may mean "the wafer itself" or "a laminate (assembly) of a wafer and a predetermined layer, film, etc. formed on its surface" (i.e., the predetermined layer, film, etc. formed on the surface is referred to as a wafer). In addition, in this specification, the term "surface of a wafer" may mean "the surface (exposed surface) of the wafer itself" or "the surface of a predetermined layer, film, etc. formed on a wafer, i.e., the outermost surface of the wafer as a laminate." In this specification, the term "substrate" is used in the same way as the term "wafer."

[0049] Therefore, in this specification, when it is stated that "a predetermined gas is supplied to a wafer," it may mean that "a predetermined gas is supplied directly to the surface (exposed surface) of the wafer itself," or that "a predetermined gas is supplied to a layer or film, etc., formed on the wafer, i.e., to the outermost surface of the wafer as a laminate." Furthermore, in this specification, when it is stated that "a predetermined layer (or film) is formed on a wafer," it may mean that "a predetermined layer (or film) is formed directly on the surface (exposed surface) of the wafer itself," or that "a predetermined layer (or film) is formed on a layer or film, etc., formed on the wafer, i.e., on the outermost surface of the wafer as a laminate."

[0050] In this specification, the processing temperature refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. Furthermore, the processing time refers to the time the processing continues. These terms also apply to the following explanations.

[0051] The substrate processing method shown in FIG. 3 will be described in detail below.

[0052] (Board loading process) In the substrate loading process, (wafer charging and boat loading) and (pressure adjustment and temperature adjustment) are performed.

[0053] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in Fig. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0054] (pressure and temperature regulation) The processing chamber 201, i.e., the space in which the wafer 200 is present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so as to reach a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on this measured pressure information. Furthermore, the wafer 200 inside the processing chamber 201 is heated by the heater 207 so as to reach a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so as to achieve a desired temperature distribution inside the processing chamber 201. Furthermore, the rotation mechanism 267 starts to rotate the wafer 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafer 200 are all continued at least until the processing of the wafer 200 is completed.

[0055] (film formation step) Next, a film-forming step is performed. The film-forming step includes the following steps: (a) a first modifying gas supply step (first reaction-inhibiting gas supply step), (b) a source gas supply step (halogen-based source gas supply step), (P1) a first residual gas removal step, (c) a second modifying gas supply step (second reaction-inhibiting gas supply step), (d) a reactive gas supply step (N-containing gas supply step), and (P2) a residual gas removal step. Here, steps (a) to (P2) are performed a predetermined number of times. In this example, steps (a) to (P2) are performed a predetermined number of times, and then an etching step (e) is performed.

[0056] (a) First reforming gas supply step (first reaction-inhibiting gas supply step) First, the valve 243b is opened to allow a first modifying gas (first inorganic halogen-containing gas, first reaction-inhibiting gas) to flow into the gas supply pipe 232b. The flow rate of the first modifying gas flowing through the gas supply pipe 232b is adjusted by the MFC 241b. The flow rate-adjusted first modifying gas is supplied from the nozzle 249b into the processing chamber 201 and exhausted from the exhaust pipe 231. At this time, the first modifying gas is supplied to the wafer 200. That is, the surface of the wafer 200 is exposed to the first modifying gas. At the same time, the valve 243g is opened to allow N2 gas to flow into the gas supply pipe 232g. The flow rate of the N2 gas flowing through the gas supply pipe 232g is adjusted by the MFC 241g. The flow rate-adjusted N2 gas is supplied into the processing chamber 201 together with the first modifying gas and exhausted from the exhaust pipe 231.

[0057] 6, the partial pressure of the first modifying gas in the processing chamber 201 at (a) (hereinafter referred to as the partial pressure of the first modifying gas) may be set higher than the partial pressure of the second modifying gas in the processing chamber 201 at (c) (hereinafter referred to as the partial pressure of the second modifying gas), which will be described later. Hereinafter, an example in which the partial pressure of the first modifying gas is higher than the partial pressure of the second modifying gas will be described.

[0058] Here, the partial pressures of the first modifying gas and the second modifying gas can be increased or decreased by, for example, at least one of the ratio of the amount of the first modifying gas and the amount of the second modifying gas to the amount of all gases (e.g., mass, volume, amount of substance, etc.) present in the processing chamber 201 (hereinafter referred to as the concentration of the first modifying gas and the concentration of the second modifying gas), or the pressure in the processing chamber 201 in (a) and (c) (hereinafter referred to as the total pressure in (a) and the total pressure in (c)). Therefore, when the partial pressure of the first modifying gas is higher than the partial pressure of the second modifying gas, the conditions for performing (a) and (c) are preferably set so that at least one of the conditions that the concentration of the first modifying gas is higher than the concentration of the second modifying gas or the condition that the total pressure in (c) is higher than the total pressure in (a) is satisfied. More preferably, the conditions for performing (a) and (c) are set so that both conditions are satisfied.

[0059] The concentration of the first modifying gas can be changed, for example, by controlling the ratio of the flow rate of the first modifying gas to the flow rate of the inert gas supplied per unit time into the processing chamber 201 in (a). Also, the total pressure in (a) can be changed, for example, by controlling the ratio of the flow rate of the gas supplied per unit time into the processing chamber 201 to the flow rate of the gas exhausted per unit time from the processing chamber 201 in (a).

[0060] Similarly, the concentration of the second modifying gas can be changed, for example, by controlling the ratio of the flow rate of the second modifying gas to the flow rate of the inert gas supplied per unit time into the processing chamber 201 in (c). Also, the total pressure in (c) can be changed, for example, by controlling the ratio of the flow rate of the gas supplied per unit time into the processing chamber 201 to the flow rate of the gas exhausted per unit time from the processing chamber 201 in (c).

[0061] At this time, the vacuum pump 264 and the APC valve 244 are appropriately adjusted to set the pressure inside the processing chamber 201 to a (predetermined) pressure within a range of, for example, 1 to 13,300 Pa, preferably a (predetermined) pressure within a range of 1 to 1,330 Pa, and more preferably a (predetermined) pressure within a range of 1 to 133 Pa. If the pressure inside the processing chamber 201 is higher than 13,300 Pa, the first modifying gas may react (or be adsorbed) excessively with the wafers 200, which may inhibit the adsorption of the source gas (described later) onto the surfaces (including trenches) of the wafers 200 by more than a predetermined amount. If the pressure inside the processing chamber 201 is lower than 1 Pa, the first modifying gas may not be able to sufficiently inhibit the adsorption of the source gas.

[0062] The supply flow rate of the first modifying gas controlled by the MFC 241b is equal to or less than the amount required to completely cover the surface of the wafer 200, and is, for example, a (predetermined) flow rate in the range of 1 to 3000 sccm, preferably a (predetermined) flow rate in the range of 10 to 1000 sccm, and more preferably a (predetermined) flow rate in the range of 10 to 500 sccm. If the supply flow rate of the first modifying gas is greater than 3000 sccm, the first modifying gas may significantly penetrate to the bottom of the trench, which may affect film formation at the bottom of the trench. If the supply flow rate of the first modifying gas is less than 1 sccm, it may be difficult to obtain the effect of the first modifying gas in inhibiting adsorption of the source gas.

[0063] The supply flow rate of the inert gas controlled by the MFC 241g is, for example, a (predetermined) flow rate within a range of 1 to 20,000 sccm, preferably a (predetermined) flow rate within a range of 10 to 15,000 sccm, and more preferably a (predetermined) flow rate within a range of 100 to 10,000 sccm. If the supply flow rate of the inert gas is more than 20,000 sccm, it may be difficult to obtain the effect of inhibiting the adsorption of the raw material gas by the first modifying gas. If the supply flow rate of the inert gas is less than 1 sccm, the residual gas removal described below may not be performed sufficiently.

[0064] The time for which the first modifying gas is supplied to the wafers 200, i.e., the gas supply time (irradiation time), is, for example, a (predetermined) time within a range of 0.01 to 120 seconds, preferably a (predetermined) time within a range of 0.1 to 60 seconds, and more preferably a (predetermined) time within a range of 1 to 10 seconds. If the gas supply time is longer than 120 seconds, the first modifying gas may react (adsorb) excessively with the wafers 200, inhibiting the reaction between the source gas and the surface of the wafers 200 by more than a predetermined amount. If the gas supply time is shorter than 1 second, the first modifying gas may not be able to sufficiently inhibit the adsorption of the source gas.

[0065] The temperature of the heater 207 is set so that the temperature of the wafer 200 is, for example, a (predetermined) temperature within a range of 200 to 600° C., preferably a (predetermined) temperature within a range of 200 to 550° C., and more preferably a (predetermined) temperature within a range of 300 to 500° C. This temperature is preferably set to the same temperature as that in the next (b) source gas supply step.

[0066] (b) Source gas supply step (halogen-based source gas supply) Thereafter, the valve 243b is closed to stop the supply of the first modifying gas. 、 The inert gas supply is stopped.

[0067] Next, the valve 243a is opened, and a source gas containing a first element (e.g., a gas containing a halogen element) is flowed into the gas supply pipe 232a. The flow rate of the source gas flowing through the gas supply pipe 232a is adjusted by the MFC 241a. The flow rate-adjusted source gas is supplied from the nozzle 249a into the processing chamber 201 and exhausted from the exhaust pipe 231. At this time, the source gas is supplied to the wafer 200. That is, the surface of the wafer 200 (including the trench) is exposed to the source gas. At the same time, the valve 24f is opened, and an inert gas such as N2 gas is flowed into the gas supply pipe 232f. The flow rate of the N2 gas flowing through the gas supply pipe 232f is adjusted by the MFC 241f. The flow rate-adjusted N2 gas is supplied into the processing chamber 201 together with the source gas and exhausted from the exhaust port 231a.

[0068] In (b), the source gas is inhibited from being adsorbed to the areas where the first modifying gas has been adsorbed in (a), and is adsorbed to areas where the first modifying gas has not been adsorbed. That is, in (b), the source gas is supplied to the wafer 200, and the source gas is preferentially adsorbed to areas that have not been modified by the first modifying gas.

[0069] At this time, the vacuum pump 264 and the APC valve 244 are appropriately adjusted to set the pressure inside the processing chamber 201 to, for example, a (predetermined) pressure within a range of 1 to 70,000 Pa, preferably a (predetermined) pressure within a range of 1 to 1,333 Pa, and more preferably a (predetermined) pressure within a range of 20 to 50 Pa. If the pressure inside the processing chamber 201 is higher than 70,000 Pa, the residual gas removal described below may not be performed sufficiently. If the pressure inside the processing chamber 201 is lower than 0.01 Pa, the reaction rate between the source gas and the surface of the wafer 200 may not be sufficiently achieved.

[0070] The supply flow rate of the source gas controlled by the MFC 241a is sufficient to cover the entire surface of the wafer 200 (including the inner surface of the trench), and is, for example, a (predetermined) flow rate within a range of 1 to 10,000 sccm, preferably a (predetermined) flow rate within a range of 10 to 5,000 sccm, and more preferably a (predetermined) flow rate within a range of 100 to 3,000 sccm. If the supply flow rate of the source gas is greater than 10,000 sccm, a large amount of impurities such as halogen elements may be incorporated into the film, and the residual gas removal described below may not be performed sufficiently. If the supply flow rate of the source gas is less than 1 sccm, the reaction rate between the source gas and the wafer 200 surface may not be sufficient.

[0071] The supply flow rate of N2 gas controlled by the MFC 241f is, for example, a (predetermined) flow rate within a range of 1 to 20,000 sccm, preferably a (predetermined) flow rate within a range of 500 to 15,000 sccm, and more preferably a (predetermined) flow rate within a range of 600 to 800 sccm. If the supply flow rate of N2 gas is greater than 20,000 sccm, the reaction rate between the source gas and the surface of the wafer 200 may not be sufficiently achieved. If the supply flow rate of N2 gas is less than 1 sccm, the residual gas removal described below may not be performed sufficiently.

[0072] The time for supplying the source gas to the wafer 200, i.e., the source gas supply time (irradiation time), is, for example, within a (predetermined) range of 0.1 to 500 seconds, preferably within a (predetermined) range of 1 to 300 seconds, and more preferably within a (predetermined) range of 3 to 200 seconds. If the source gas supply time is longer than 500 seconds, a large amount of the source gas may be adsorbed, which may reduce the uniformity of the film thickness. If the source gas supply time is shorter than 0.1 seconds, the source gas may not sufficiently react with the surface of the wafer 200.

[0073] The temperature of the heater 207 is set so that the temperature of the wafer 200 is, for example, a (predetermined) temperature in the range of 200 to 600°C, preferably a (predetermined) temperature in the range of 200 to 550°C, and more preferably a (predetermined) temperature in the range of 300 to 500°C. If the temperature of the heater 207 is higher than 600°C, the thermal decomposition of the source gas is accelerated, which may lead to a decrease in the uniformity of the film thickness and an increase in resistivity due to the incorporation of a large amount of impurities. On the other hand, if the temperature of the heater 207 is lower than 200°C, the reactivity with the surface of the wafer 200 may decrease, making film formation difficult.

[0074] The gases flowing inside the processing chamber 201 are only the source gas and N2 gas, and the supply of the source gas forms a first element-containing layer on the wafer 200 (underlying film on the surface).

[0075] The first-element-containing layer may be a first-element layer composed of the first element, a first-element layer containing an element other than the first element, such as a halogen element, an adsorption layer of source gas molecules (hereinafter simply referred to as an adsorption layer of source molecules), or all of these. The first-element layer containing an element other than the first element is a general term that includes not only a continuous layer composed of the first element and containing an element other than the first element, but also a discontinuous layer and a film formed by overlapping these layers and containing the first element. A continuous layer composed of the first element and containing an element other than the first element may also be referred to as a film containing the first element containing an element other than the first element. The first element constituting the first-element-containing layer may include a layer in which bonds with elements other than the first element are not completely broken, as well as a layer in which bonds with elements other than the first element are completely broken.

[0076] The adsorption layer of the raw material molecules includes not only a continuous adsorption layer composed of raw material gas molecules but also a discontinuous adsorption layer. That is, the adsorption layer of the raw material molecules includes an adsorption layer composed of raw material gas molecules and having a thickness of one molecular layer or less than one molecular layer. The raw material gas molecules constituting the adsorption layer of the raw material molecules also include those in which the bond between the first element and an element other than the first element is partially broken. That is, the adsorption layer of the raw material molecules may be a physisorption layer of raw material gas molecules, a chemisorption layer of raw material gas molecules, or may include both.

[0077] Here, a layer less than one atomic layer thick means an atomic layer that is formed discontinuously, and a layer one atomic layer thick means an atomic layer that is formed continuously. A layer less than one molecular layer thick means a molecular layer that is formed discontinuously, and a layer one molecular layer thick means a molecular layer that is formed continuously. A first-element-containing layer containing an element other than the first element may include both a first-element layer containing an element other than the first element and an adsorption layer of raw material molecules. However, as described above, a first-element-containing layer containing an element other than the first element will be expressed using expressions such as "one atomic layer" or "several atomic layers."

[0078] Under conditions in which the source gas self-decomposes (thermally decomposes), a first element layer is formed by depositing a first element on the wafer 200. Under conditions in which the source gas does not self-decompose (thermally decompose), molecules of the source gas are adsorbed onto the wafer 200, forming an adsorption layer of the source molecules. Forming a first element layer on the wafer 200 is preferable to forming an adsorption layer of the source molecules on the wafer 200, in that it can increase the film formation rate.

[0079] If the thickness of the first-element-containing layer (hereinafter sometimes referred to as the first layer) formed in one (b) source gas supply step exceeds several atomic layers, the modification effect in the (d) reactive gas supply step (N-containing gas supply step) described later will not reach the entire first layer. Furthermore, the minimum thickness of the first layer is less than one atomic layer. Therefore, it is preferable that the thickness of the first layer be less than one atomic layer to several atomic layers. By making the thickness of the first layer one atomic layer or less, i.e., one atomic layer or less, the efficiency of the reaction in the (d) reactive gas supply step described later can be relatively increased, and the time required for the reaction in the (d) reactive gas supply step can be shortened. The time required to form the first layer in the (b) source gas supply step can also be shortened. As a result, the processing time per cycle can be shortened, and the total processing time can also be shortened. That is, the film formation rate can also be increased. Furthermore, by making the thickness of the first layer one atomic layer or less, it is possible to improve the controllability of film thickness uniformity.

[0080] (P1) First residual gas removal step Thereafter, the valve 243a is closed to stop the supply of the source gas. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated by the vacuum pump 264 to remove the first modifying gas and reaction by-products remaining in the processing chamber 201, which have not reacted or which have acted as a reaction inhibitor gas, from the processing chamber 201. At this time, as in the (b) source gas supply step, it is not necessary to completely remove the gases remaining in the processing chamber 201.

[0081] (c) Second reforming gas supply step (second reaction inhibitor gas supply step) Next, the valve 243d is opened, and the second modifying gas is allowed to flow into the gas supply pipe 232d. The flow rate of the second modifying gas flowing through the gas supply pipe 232d is adjusted by the MFC 241d. The flow rate-adjusted second modifying gas is supplied from the nozzle 249d into the processing chamber 201 and exhausted from the exhaust pipe 231. At this time, the second modifying gas is supplied to the wafers 200. That is, the surfaces of the wafers 200 are exposed to the second modifying gas. At the same time, the valve 243i is opened, and N2 gas is allowed to flow into the gas supply pipe 232i. The flow rate of the N2 gas flowing through the gas supply pipe 232i is adjusted by the MFC 241i. The flow rate-adjusted N2 gas is supplied into the processing chamber 201 together with the second modifying gas and exhausted from the exhaust pipe 231.

[0082] By appropriately adjusting the vacuum pump 264 and the APC valve 244, the pressure inside the processing chamber 201 is set to, for example, a (predetermined) pressure in the range of 1 to 13,300 Pa, preferably a (predetermined) pressure in the range of 1 to 1,330 Pa, and more preferably a (predetermined) pressure in the range of 1 to 133 Pa. If the pressure inside the processing chamber 201 is higher than 13,300 Pa, the second modifying gas may react (or be adsorbed) excessively with the wafers 200, which may inhibit the reaction between the first element-containing layer and the reactive gas to a predetermined extent or more, as described below. If the pressure inside the processing chamber 201 is lower than 1 Pa, the reaction rate between the second modifying gas and the first element-containing layer may not be sufficiently high.

[0083] The supply flow rate of the second modifying gas controlled by the MFC 241d is equal to or less than the amount required to completely cover the surface of the wafer 200, and is set to, for example, a (predetermined) flow rate in the range of 1 to 3000 sccm, preferably a (predetermined) flow rate in the range of 10 to 1000 sccm, and more preferably a (predetermined) flow rate in the range of 10 to 500 sccm. If the supply flow rate of the second modifying gas is greater than 3000 sccm, the second modifying gas may significantly penetrate to the bottom of the trench, which may affect film formation at the bottom of the trench. If the supply flow rate of the second modifying gas is less than 1 sccm, the second modifying gas may not be able to sufficiently inhibit the reaction between the first-element-containing layer and the reactive gas.

[0084] The N2 gas supply flow rate controlled by the MFC 241g is, for example, a (predetermined) flow rate within a range of 1 to 20,000 sccm, preferably a (predetermined) flow rate within a range of 10 to 15,000 sccm, and more preferably a (predetermined) flow rate within a range of 100 to 10,000 sccm. If the N2 gas supply flow rate is greater than 20,000 sccm, the reaction rate between the second modifying gas and the first element-containing layer may not be sufficiently achieved. If the N2 gas supply flow rate is less than 1 sccm, the residual gas removal described below may not be performed sufficiently.

[0085] The time for which the second modifying gas is supplied to the wafers 200, i.e., the gas supply time (irradiation time), is, for example, a (predetermined) time within a range of 0.01 to 120 seconds, preferably a (predetermined) time within a range of 0.1 to 60 seconds, and more preferably a (predetermined) time within a range of 1 to 10 seconds. If the gas supply time is longer than 120 seconds, the second modifying gas may react (adsorb) excessively with the wafers 200, inhibiting the reaction between the first element-containing layer and the reactive gas by more than a predetermined amount. If the gas supply time is shorter than 1 second, the effect of inhibiting the reaction between the first element-containing layer and the reactive gas may not be sufficiently obtained.

[0086] The temperature of the heater 207 is set so that the temperature of the wafer 200 is, for example, a (predetermined) temperature within a range of 200 to 600° C., preferably a (predetermined) temperature within a range of 200 to 550° C., and more preferably a (predetermined) temperature within a range of 300 to 500° C. This temperature is preferably set to the same temperature as that in the next (b) source gas supply step.

[0087] (d) Reactant gas supply step Next, the valve 243c is opened, and a reactive gas is allowed to flow into the gas supply pipe 232c. The reactive gas is, for example, an N-containing gas or a reducing gas. The flow rate of the reactive gas flowing through the gas supply pipe 232c is adjusted by the MFC 241c. The flow rate-adjusted reactive gas is supplied into the processing chamber 201 from the nozzle 249c and exhausted from the exhaust pipe 231. At the same time, the valve 243h is opened, and N2 gas is allowed to flow into the gas supply pipe 232h. The flow rate of the N2 gas flowing through the gas supply pipe 232h is adjusted by the MFC 241h. The N2 gas is supplied into the processing chamber 201 together with the reactive gas and exhausted from the exhaust pipe 231.

[0088] When flowing the reactive gas, the pressure regulator 244 is appropriately adjusted to set the pressure inside the processing chamber 201 to a (predetermined) pressure within a range of, for example, 0.01 to 13,300 Pa, preferably a (predetermined) pressure within a range of 1 to 1,330 Pa, and more preferably a (predetermined) pressure within a range of 10 to 133 Pa. If the pressure inside the processing chamber 201 is higher than 13,300 Pa, the residual gas removal described below may not be performed sufficiently. If the pressure inside the processing chamber 201 is lower than 0.01 Pa, a sufficient film formation rate may not be obtained.

[0089] The supply flow rate of the reactive gas controlled by the MFC 241c is sufficient to cover the entire surface of the wafer 200, and is, for example, a (predetermined) flow rate within the range of 10 to 50,000 sccm, preferably a (predetermined) flow rate within the range of 300 to 10,000 sccm, and more preferably a (predetermined) flow rate within the range of 1,000 to 8,000 sccm. A higher supply flow rate of the reactive gas is preferable because it can reduce the incorporation of impurities derived from the source gas into the film. If it is greater than 50,000 sccm, there is a possibility that the residual gas cannot be sufficiently removed in the residual gas removal step described below. If the supply flow rate of the reactive gas is less than 10 sccm, there is a possibility that the gas will not react sufficiently with the first element-containing layer.

[0090] The N2 gas supply flow rate controlled by the MFC 241h is, for example, a (predetermined) flow rate within a range of 10 to 20,000 sccm, preferably a (predetermined) flow rate within a range of 400 to 15,000 sccm, and more preferably a (predetermined) flow rate within a range of 400 to 7,500 sccm. If the N2 gas supply flow rate is greater than 20,000 sccm, the film formation rate may be too low. If the N2 gas supply flow rate is less than 10 sccm, the reactive gas may not be sufficiently supplied to the wafers 200.

[0091] The time for supplying the reactive gas to the wafer 200, i.e., the gas supply time (irradiation time), is, for example, a (predetermined) time in the range of 0.001 to 300 seconds, preferably a (predetermined) time in the range of 0.1 to 200 seconds, and more preferably a (predetermined) time in the range of 5 to 60 seconds. A longer gas supply time is preferable because it can reduce the incorporation of impurities derived from the source gas into the film, but if it is longer than 300 seconds, throughput may deteriorate. If the gas supply time is shorter than 0.001 second, the reaction rate with the first element-containing layer may not be sufficient.

[0092] The temperature of the heater 207 is set to the same temperature as that in the source gas supply step.

[0093] At this time, only the reactive gas and N2 gas are flowing into the processing chamber 201. The reactive gas undergoes a substitution reaction with at least a portion of the first-element-containing layer formed on the wafer 200 in the source gas supply step that did not react with the second modifying gas in the second modifying gas supply step. The substitution reaction forms a layer containing the first element and an element contained in the reactive gas on the wafer 200. The inclusion of the first element and an element contained in the reactive gas may include the first-element-containing layer that did not undergo the substitution reaction and other elements derived from each source material contained in the first-element-containing layer.

[0094] (P2) Residual gas removal step After forming the layer containing the first element and the element contained in the reactive gas, the valve 243e is closed to stop the supply of the reactive gas. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated by the vacuum pump 264 to remove unreacted reactive gas, reaction by-products, reactive gas after contributing to the formation of the layer containing the first element and the element contained in the reactive gas, and the like remaining in the processing chamber 201.

[0095] (Performed a specified number of times) The above-mentioned film formation sequence ((a) first modifying gas supply step, (b) raw material gas supply step, (P1) first residual gas removal step, (c) second modifying gas supply step, (d) reactive gas supply step, (P2) residual gas removal step) is considered as one cycle, and these processes are performed n cycles (n is an integer equal to or greater than 1). In this way, a film of a predetermined thickness (for example, 0.1 to 10 nm) is formed on the wafer 200. It is preferable to repeat the above-mentioned cycle multiple times.

[0096] When the cycle is performed multiple times, in each step at least from the second cycle onwards, the part that says "gas is supplied to wafer 200" means "a predetermined gas is supplied to the layer formed on wafer 200, i.e., to the outermost surface of wafer 200 as a laminate", and the part that says "a predetermined layer is formed on wafer 200" means "a predetermined layer is formed on top of the layer formed on wafer 200, i.e., on the outermost surface of wafer 200 as a laminate".

[0097] (e) Etching step (etching process) Thereafter, the valve 243e is opened to allow the etching gas to flow into the gas supply pipe 232e. The flow rate of the etching gas flowing through the gas supply pipe 232e is adjusted by the MFC 241e. The flow rate-adjusted etching gas is supplied from the nozzle 249e into the processing chamber 201 and exhausted from the exhaust pipe 231. At this time, the etching gas is supplied to the wafer 200. As a result, a portion of the film formed on the surface of the wafer 200 is etched. When the etching step is completed, the valve 243e is closed to stop the supply of the etching gas.

[0098] By appropriately adjusting the vacuum pump 264 and the APC valve 244, the pressure inside the processing chamber 201 is set to, for example, a (predetermined) pressure within the range of 1 to 13,300 Pa, preferably a (predetermined) pressure within the range of 1 to 1,330 Pa, and more preferably a (predetermined) pressure within the range of 1 to 133 Pa.

[0099] The supply flow rate of the etching gas controlled by the MFC 241e is equal to or less than the amount required to cover the entire surface of the wafer 200, and is set to, for example, a (predetermined) flow rate within the range of 1 to 3000 sccm, preferably a (predetermined) flow rate within the range of 10 to 1000 sccm, and more preferably a (predetermined) flow rate within the range of 10 to 500 sccm.

[0100] The supply flow rate of N2 gas controlled by the MFC 241h is, for example, a (predetermined) flow rate within the range of 1 to 40,000 sccm, preferably a (predetermined) flow rate within the range of 10 to 3,000 sccm, and more preferably a (predetermined) flow rate within the range of 100 to 20,000 sccm.

[0101] The time for which the etching gas is supplied to the wafer 200, i.e., the gas supply time (irradiation time), is set to, for example, a (predetermined) time within the range of 0.1 to 300 seconds, preferably a (predetermined) time within the range of 1 to 200 seconds, and more preferably a (predetermined) time within the range of 5 to 100 seconds.

[0102] After the above-described etching step (e), the APC valve 244 of the exhaust pipe 231 may be left open, and the processing chamber 201 may be evacuated to a vacuum by the vacuum pump 264. Furthermore, performing a cycle of the above-described etching step (e) and the evacuation of the processing chamber 201 performed after the etching step (e) in this order a predetermined number of times (one or more times) may be considered as the etching step (e).

[0103] (Performed a specified number of times) The above-mentioned "n film formation sequences and etching sequences ((e) etching step)" are considered as one cycle, and these processes are performed L cycles (L is an integer equal to or greater than 0). As a result, a film of a predetermined thickness (for example, 0.1 to 10 nm) is formed on the wafer 200. It is preferable to repeat this cycle multiple times.

[0104] When the cycle of performing the film formation sequence and the etching sequence is performed multiple times, the inside of the recess 300 is gradually filled with the film 400, as shown in State A in Fig. 5. Then, finally, the inside of the recess 300 is completely filled with the film 400, as shown in State B.

[0105] (Substrate unloading process) (After-purge step, atmospheric pressure return step) Valves 243f-243j are opened, and N2 gas is supplied into the processing chamber 201 from each of gas supply pipes 232f-232j and exhausted from the exhaust pipe 231. The N2 gas acts as a purge gas, thereby purging the processing chamber 201 with the inert gas, and gases and by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

[0106] Thereafter, the seal cap 219 is lowered by the boat elevator 115 to open the lower end of the outer tube 203. Then, the processed wafers 200 supported by the boat 217 are unloaded from the lower end of the outer tube 203 to the outside of the outer tube 203 (boat unloading). Thereafter, the processed wafers 200 are removed from the boat 217 (wafer discharging).

[0107] According to this embodiment, one or more of the following effects can be obtained.

[0108] As shown in FIG. 3, a predetermined number of cycles are performed in the order of (a)->(b)->(c)->(d). In (a) and (c), the first modifying gas and the second modifying gas preferentially modify areas that are easily accessible (such as the top 301 of the recess 300) and are less likely to modify areas that are difficult for the gas to reach (such as the bottom 302 of the recess 300). Therefore, in (b), the adsorption of the source gas to areas that are easily accessible is inhibited, while the adsorption of the source gas to areas that are difficult for the gas to reach is less inhibited. Furthermore, in (d), the reaction between the reactant gas and the source gas is inhibited in areas that are easily accessible, while the reaction between the reactant gas and the source gas is less inhibited in areas that are difficult for the gas to reach. Therefore, a film of uniform thickness can be formed from areas that are easily accessible to areas that are difficult for the gas to reach (such as the bottom 302 of the recess 300). Since halogen elements are unlikely to remain as impurities in the film, deterioration of electrical characteristics can be suppressed.

[0109] In (c), the area where the second modifying gas adsorbs on the substrate 200 may be configured to be smaller than the area where the first modifying gas adsorbs on the substrate in (a). For example, in (c), the area where the second modifying gas modifies the bottom 302 of the recess 300 may be configured to be smaller than the area where the first modifying gas modifies the bottom 302 of the recess 300 in (a). This increases the area where the reaction between the source gas and the reactant gas is not inhibited in areas where the gas is difficult to reach. This reduces the amount of unreacted source gas in areas where the gas is difficult to reach, thereby preventing deterioration of the electrical properties of the film. This prevents an increase in film thickness (film growth) in areas where the gas is easy to reach, improving step coverage and preventing the occurrence of voids. Furthermore, reduced consumption of the reactant gas in areas where the gas is easy to reach makes it easier for the gas to reach the bottom. This reduces the amount of unreacted source gas in areas where the gas is easy to reach.

[0110] In (c), the amount of the second modifying gas adsorbed in areas where the gas has difficulty reaching (for example, the bottom 302 of the recess 300) may be configured to be less than the amount of the first modifying gas adsorbed in areas where the gas has difficulty reaching in (a). This makes it less likely that the reaction between the source gas and the reactive gas will be hindered in areas where the gas has difficulty reaching in (d). This makes it less likely that the reaction between the source gas and the reactive gas will be hindered in areas where the gas has difficulty reaching, improving step coverage or suppressing the occurrence of voids. Furthermore, since the amount of unreacted source gas in areas where the gas has difficulty reaching is reduced, impurities in the film are reduced, and the electrical properties of the film can be improved.

[0111] In (c), the amount of the second modifying gas adsorbed in the areas where the gas can easily reach (for example, the upper part 301 of the recess 300) may be greater than the amount adsorbed in the areas where the gas can easily reach in (a). This makes it easier to inhibit the reaction between the source gas and the reactive gas in the areas where the gas can easily reach in (d). This suppresses film growth in the areas where the gas can easily reach, improving step coverage or suppressing the occurrence of voids. Furthermore, since consumption of the reactive gas in the areas where the gas can easily reach is reduced, the gas can more easily reach areas where it is difficult to reach. Therefore, the amount of unreacted source gas in the areas where the gas cannot easily reach is reduced, reducing impurities in the film and improving the electrical properties of the film.

[0112] As shown in FIG. 6, the partial pressure of the second modifying gas in the space (processing chamber 201) where the substrate 200 exists in (c) is set to be lower than the partial pressure of the first modifying gas in the space (processing chamber 201) in (a). When the partial pressure of the gas is lowered, the likelihood of collisions between gas molecules is greater in areas where the gas has difficulty reaching (e.g., the bottom 302 of the recess 300) than in areas where the gas can easily reach (e.g., the upper part 301 of the recess 300). Therefore, the amount of adsorption of the second modifying gas in areas where the gas has difficulty reaching can be made smaller than that of the first modifying gas. Furthermore, the amount of adsorption of the second modifying gas in areas where the gas has difficulty reaching can be made larger than that of the first modifying gas. This makes it possible to prevent the reaction between the source gas and the reactive gas from being inhibited in areas where the gas has difficulty reaching.

[0113] In an etching sequence, etching gas progresses more easily in areas where it is easy to reach (e.g., the upper portion 301 of the recess 300) than in areas where it is difficult to reach (e.g., the bottom portion 302 of the recess 300). Therefore, it is possible to reduce the film thickness in areas where film growth is likely to occur, i.e., areas where the gas is easy to reach. This improves step coverage or suppresses the occurrence of voids.

[0114] The source gas may be a gas containing a first element and a halogen element, and the reactive gas may be a reducing gas. By using a gas containing a halogen element as the source gas, which is less likely to remain as an impurity in the film, an increase in the electrical resistance of the metal film is suppressed. Furthermore, by using a reducing gas as the reactive gas, oxidation of the metal film can be suppressed.

[0115] (Variation) Next, several modified examples will be described. In each modified example, in addition to the same effects as those of the above-described embodiment, further effects as will be described later can be obtained.

[0116] (First Modification) 7 is a diagram showing a film formation sequence according to the first modified example. As shown in FIG. 7, in the first modified example, the flow rate per unit time of the second modifying gas in (c) is smaller than the flow rate per unit time of the first modifying gas in (a). By doing so, it is possible to achieve a condition in which the partial pressure of the first modifying gas in (a) is greater than the partial pressure of the second modifying gas in (c).

[0117] (Second Modification) FIG. 8 is a diagram showing a film formation sequence according to the second modified example. As shown in FIG. 8, in the second modified example, when the partial pressure of the second modifying gas is lower than the partial pressure of the first modifying gas, the supply time of the second modifying gas in (c) is longer than the supply time of the first modifying gas in (a). This makes it possible to promote the adsorption of the second modifying gas to the upper part 301 of the recess 300 while minimizing the adsorption of the second modifying gas to the bottom part 302 of the recess 300. Therefore, the reactant gas can more easily reach the bottom part 302, and the amount of unreacted source gas is reduced. Furthermore, the step coverage of the film to be formed is improved, and the occurrence of voids can be suppressed.

[0118] (Third Modification) FIG. 9 is a diagram showing a film formation sequence according to a third modified example. As shown in FIG. 9, in the third modified example, the supply time of the second modifying gas in (c) may be shorter than the supply time of the first modifying gas in (a). In this case, the adsorption amount of the second modifying gas is greater in areas where the gas can easily reach than in areas where the gas is difficult to reach. This makes it easier for the reactive gas to reach areas where the gas is difficult to reach, reducing the amount of unreacted source gas. In addition, the step coverage of the formed film can be improved and void generation can be suppressed. This is true even when the partial pressure of the first modifying gas is lower than the partial pressure of the second modifying gas, as in the embodiment, and also when the partial pressure of the first modifying gas is higher than the partial pressure of the second modifying gas. In addition, when the partial pressure of the first modifying gas is higher than the partial pressure of the second modifying gas, shortening the supply time of the second modifying gas compared to the supply time of the first modifying gas reduces the amount of unreacted source gas and improves the step coverage.

[0119] (Fourth Modification) FIG. 10 is a diagram showing a film formation sequence according to a fourth modified example. As shown in FIG. 10, in the fourth modified example, in the n1th and subsequent film formation cycles (n1 is an integer greater than or equal to 2 and less than or equal to n, 2≦n1≦n), the partial pressure of the first modifying gas in the space (processing chamber 201) in (a) is set lower than that in the n1-1th and previous film formation cycles. Instead of reducing the partial pressure of the first modifying gas, (a) may be omitted. As the cycles progress, the recesses 300 become shallower, and a void-free film can be formed by reducing the amount of adsorption of the first modifying gas or even eliminating adsorption. Therefore, by reducing the partial pressure of the first modifying gas or omitting (a), the suppression of adsorption of the source gas by the first modifying gas is reduced, thereby improving productivity.

[0120] Similarly, in the n2th (n2 is an integer greater than or equal to 2 and less than or equal to n, 2≦n2≦n) film formation cycle or later, the partial pressure of the second modifying gas in the space (processing chamber 201) in (c) may be made smaller than that in the n2-1th or earlier film formation cycle, or (c) may not be performed.

[0121] Note that, in FIG. 10, the case where n2 is a number larger than n1 (n1 < n2) is shown as an example, but the fourth modification example is not limited to this. For example, n1 may be a number larger than n2 (n2 < n1), and the film formation sequence according to the fourth modification example may be performed. Further, for example, n1 and n2 may be equal numbers (n1 = n2), and the film formation sequence according to the fourth modification example may be performed. Here, when n2 is a number larger than n1 (n1 < n2), the reaction between the reaction gas and the raw material gas by the second reforming gas is less likely to be suppressed than the adsorption of the raw material gas by the first reforming gas. Therefore, the unreacted raw material gas can be reduced, which is preferable.

[0122] (Fifth Modification Example) FIG. 11 is a diagram showing a film formation sequence according to the fifth modification example. As shown in FIG. 11, in the fifth modification example, in the film formation cycles after the m1-th time (m1 is an integer of 2 or more and n or less, 2 ≤ m1 ≤ n), in (a), the supply time of the first reforming gas to the substrate 200 is made shorter than that in the film formation cycles before the m1 - 1-th time. Note that instead of reducing the supply time of the first reforming gas, (a) may not be performed. As the cycle progresses, the recess 300 becomes shallower, and a void-free film can be formed without reducing or adsorbing the adsorption amount of the first reforming gas. Therefore, since the suppression of the adsorption of the raw material gas by the first reforming gas into the recess 300 is reduced or eliminated, the step coverage can be improved or the generation of voids can be suppressed while increasing the productivity.

[0123] Similarly, in the film formation cycles after the m2-th time (m2 is an integer of 2 or more and n or less, 2 ≤ m2 ≤ n), in (c), the supply time of the second reforming gas to the substrate 200 may be made shorter than that in the film formation cycles before the m2 - 1-th time, or (c) may not be performed.

[0124] Note that in FIG. 11, the film formation sequence according to the fifth modification example is shown by taking the case where m2 is a number larger than m1 (m1 < m2) as an example, but it is not limited thereto. That is, m1 may be a number larger than m2 (m2 < m1), and the film formation sequence according to the fifth modification example may be performed. Also, m1 and m2 may be made equal numbers (m1 = m2), and the film formation sequence according to the fifth modification example may be performed. Here, when m2 is a number larger than m1 (m1 < m2), the reaction between the reaction gas and the raw material gas by the second reforming gas is less likely to be suppressed than the adsorption of the raw material gas by the first reforming gas, so the unreacted raw material gas can be reduced, which is preferable.

[0125] In the above-described embodiment, as the raw material gas, for example, a gas containing a metal element can be used. As the metal element, for example, tantalum (Ta), tungsten (W), titanium (Ti), cobalt (Co), yttrium (Y), ruthenium (Ru), aluminum (Al), hafnium (Hf), zirconium (Zr), molybdenum (Mo), niobium (Nb), manganese (Mn), nickel (Ni), silicon (Si), etc. can be used. It can also be suitably applied when forming any one of a nitride film, an oxide film, a carbide film, a boride film containing these elements, or a composite film thereof.

[0126] When forming the film containing the above-described metal element, as the raw material gas, a Ta-containing gas, a W-containing gas, a Ti-containing gas, a Co-containing gas, a Y-containing gas, a Ru-containing gas, an Al-containing gas, a Hf-containing gas, a Zr-containing gas, a Mo-containing gas, a Nb-containing gas, a Mn-containing gas, a Ni-containing gas, a Si-containing gas, etc. can be used.

[0127] When forming a film containing the above-mentioned metal elements, a gas containing a metal element and a halogen element can be used. Examples of the gas containing a metal element and a halogen element include tantalum pentachloride (TaCl5), tantalum pentafluoride (TaF5), tungsten hexachloride (WCl6), tungsten hexafluoride (WF6), titanium tetrachloride (TiCl4), titanium tetrafluoride (TiF4), cobalt dichloride (CoCl2), cobalt dichloride (CoF2), yttrium trichloride (YCl3), yttrium trifluoride (YF3), ruthenium trichloride (RuCl3), ruthenium trifluoride (RuF3), aluminum trichloride (AlCl3), aluminum trifluoride (AlF3), hafnium tetrachloride (HfCl4), hafnium tetrafluoride (HfF4), zirconium tetrachloride (ZrCl4), and the like. It is also possible to use tetrachlorosilane (SiCl4), zirconium tetrafluoride (ZrF4), molybdenum pentafluoride (MoF5), molybdenum pentachloride (MoCl5), niobium trifluoride (NbF3), niobium trichloride (NbCl3), manganese difluoride (MnF2), manganese dichloride (MnCl2), nickel difluoride (NiF2), nickel dichloride (NiCl2), tetrachlorosilane, i.e., silicon tetrachloride or silicon tetrachloride (SiCl4, abbreviated as STC), dichlorosilane (SiH2Cl2, abbreviated as DCS), monochlorosilane (SiH3Cl, abbreviated as MCS), hexachlorodisilane, i.e., disilicon hexachloride (Si2Cl6, abbreviated as HCDS), and the like.

[0128] When forming a film containing the above-mentioned elements, a reducing gas can be used as the reactive gas. Using a reducing gas as the reactive gas can suppress oxidation of the substrate surface and the formed film, thereby suppressing an increase in the electrical resistance of the film. Examples of reducing gases that can be used include H2 gas, deuterium (D2) gas, borane (BH3) gas, diborane (B2H6) gas, carbon monoxide (CO) gas, ammonia (NH3) gas, monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, monogermane (GeH4) gas, digermane (Ge2H6), ethanol (C2H5OH), and formic acid (HCOOH). Plasma-excited versions of these gases can also be used.

[0129] Furthermore, when forming a film containing the above elements, a nitrogen (N)-containing gas can be used as the reactive gas. Examples of N-containing gases that can be used include nitrogen (N) gas, nitrous oxide (NO) gas, and gases containing N-H bonds, such as ammonia (NH), diazene (NH) gas, hydrazine (NH) gas, and NH gas. In addition to the above gases, examples of gases containing N-H bonds that can be used include organic hydrazine-based gases, such as methylhydrazine-based gases such as monomethylhydrazine ((CH)HNH, abbreviated as MMH) gas, dimethylhydrazine ((CH)NH, abbreviated as DMH) gas, and trimethylhydrazine ((CH)N(CH)H, abbreviated as TMH) gas, and ethylhydrazine-based gases such as ethylhydrazine ((CH)HNH, abbreviated as EH) gas.In addition, ethylamine gases such as triethylamine ((C2H5)3N, abbreviated as TEA) gas, diethylamine ((C2H5)2NH, abbreviated as DEA) gas, and monoethylamine (C2H5NH2, abbreviated as MEA) gas; methylamine gases such as trimethylamine ((CH3)3N, abbreviated as TMA) gas, dimethylamine ((CH3)2NH, abbreviated as DMA) gas, and monomethylamine (CH3NH2, abbreviated as MMA) gas; propylamine gases such as tripropylamine ((C3H7)3N, abbreviated as TPA) gas, dipropylamine ((C3H7)2NH, abbreviated as DPA) gas, and monopropylamine (C3H7NH2, abbreviated as MPA) gas; and triisopropylamine ([(CH3)2CH]3N, abbreviated as TIPA) gas. Examples of gases that can be used include isopropylamine-based gases such as diisopropylamine ([(CH3)2CH]2NH, abbreviated as DIPA) gas and monoisopropylamine ((CH3)2CHNH2, abbreviated as MIPA) gas, butylamine-based gases such as tributylamine ((C4H9)3N, abbreviated as TBA) gas, dibutylamine ((C4H9)2NH, abbreviated as DBA) gas and monobutylamine (C4H9NH2, abbreviated as MBA) gas, and isobutylamine-based gases such as triisobutylamine ([(CH3)2CHCH2]3N, abbreviated as TIBA) gas, diisobutylamine ([(CH3)2CHCH2]2NH, abbreviated as DIBA) gas and monoisobutylamine ((CH3)2CHCH2NH2, abbreviated as MIBA) gas. Furthermore, plasma-excited versions of these gases may also be used. That is, the amine-based gas can be at least one gas represented by the composition formula (C2H5)xNH3-x, (CH3)xNH3-x, (C3H7)xNH3-x, [(CH3)2CH]xNH3-x, (C4H9)xNH3-x, or [(CH3)2CHCH2]xNH3-x (where x is an integer of 1 to 3). The use of an organic hydrazine-based gas or an amine-based gas can increase reactivity and incorporate carbon (C) into the film, allowing the work function of the film to be adjusted by controlling the C concentration.

[0130] The first and second modifying gases may be, for example, inorganic halogen-containing gases (halogen-based gases). Inorganic halogen-containing gases do not contain carbon, which is easily incorporated into the film, but are composed of halogen elements, which are easily desorbed from the film, thereby suppressing the impact on electrical characteristics. The inorganic halogen-containing gas may be, for example, hydrogen halide gas (hydrogen halide). Examples of hydrogen halide gases that may be used include hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI). Alternatively, the first and second modifying gases may be inorganic halogen-containing gases other than hydrogen halide gas, such as chlorine (Cl2) gas, fluorine (F2) gas, NF3 gas, and tungsten hexafluoride (WF6) gas. The first and second modifying gases may be different gases.

[0131] The etching gas may be, for example, a gas containing a halogen element, such as chlorine (Cl) gas, fluorine (F) gas, NF gas, HF gas, or HCl gas.

[0132] In the above-described embodiment, an example in which N2 gas is used as the inert gas has been described, but this is not limiting, and rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas may also be used.

[0133] Although the above has been specifically described based on examples, it goes without saying that the present invention is not limited to the above-described embodiments and examples, and various modifications are possible. Furthermore, the above-described aspects and modifications can be used in appropriate combinations. The processing procedures and processing conditions in such cases can be, for example, the same as those of the above-described aspects and modifications. [Explanation of symbols]

[0134] 200: Wafer (substrate) 201: Processing room 248: Integrated supply system 121: Controller (control unit)

Claims

1. For the substrate, (a) supplying a first modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, and allowing the first modifying gas to be adsorbed onto a portion of the substrate; (b) supplying a source gas containing a metal element and a halogen element, the source gas being inhibited from being adsorbed by the first modifying gas adsorbed on the substrate, and allowing the source gas to be adsorbed on another part of the substrate, thereby forming an adsorption layer of molecules of the source gas; (c) supplying a second modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, and reacting a portion of the adsorption layer with the second modifying gas; (d) supplying a reaction gas, which is a nitrogen-containing gas or a reducing gas, to cause a substitution reaction between another portion of the adsorption layer and the reaction gas; a cycle of performing the above steps in this order a predetermined number of times.

2. 2. The substrate processing method according to claim 1, wherein an area where the second modifying gas is adsorbed on the substrate in (c) is made smaller than an area where the first modifying gas is adsorbed on the substrate in (a).

3. The substrate processing method of claim 1 , wherein the substrate has a recess.

4. 4. The substrate processing method according to claim 3, wherein the amount of the second modifying gas adsorbed to the bottom of the recess in (c) is set to be less than the amount of the first modifying gas adsorbed to the bottom of the recess in (a).

5. 4. The substrate processing method according to claim 3, wherein the amount of the second modifying gas adsorbed above the recess in (c) is set to be greater than the amount of the first modifying gas adsorbed above the recess in (a).

6. 6. The substrate processing method according to claim 2, wherein the partial pressure of the second modifying gas in the space in which the substrate is present in (c) is lower than the partial pressure of the first modifying gas in the space in (a).

7. A substrate processing method as described in claim 6, wherein the flow rate of the second modifying gas supplied to the substrate per unit time in (c) is less than the flow rate of the first modifying gas supplied to the substrate per unit time in (a).

8. 7. The substrate processing method according to claim 6, wherein the time during which the second modifying gas is supplied to the substrate in (c) is set longer than the time during which the first modifying gas is supplied to the substrate in (a).

9. (c) a time for supplying the second modifying gas to the substrate; 6. The substrate processing method according to claim 2, wherein in (a), the time for which the first modifying gas is supplied to the substrate is set shorter than the time for which the first modifying gas is supplied to the substrate.

10. In the n1th (n1 is an integer of 2 or more) or later cycle, (a) making the partial pressure of the first reforming gas in the space lower than that of the cycles before the (n1-1)th cycle, or (a) not being performed; The substrate processing method according to claim 1 .

11. In the n2th (n2 is an integer of 2 or more) or later cycle, (c) making the partial pressure of the second reforming gas in the space lower than that of the cycles before the (n2-1)th time, or (c) not being performed; The substrate processing method according to claim 1 .

12. In the m1th (m1 is an integer of 2 or more) or later cycle, In (a), the time for supplying the first modifying gas to the substrate is made shorter than that in the cycles before m1-1, or (a) is not performed. The substrate processing method according to claim 1 .

13. In the m2th (m2 is an integer of 2 or more) or later cycle, In (c), the time for supplying the second modifying gas to the substrate is made shorter than that in the cycles before m2-1, or (c) is not performed. The substrate processing method according to claim 1 .

14. At least one of the cycles includes, after performing (d), (e) supplying an etching gas to the substrate; The method of claim 1 , further comprising:

15. 15. The substrate processing method according to claim 14, wherein the etching gas is a gas containing a halogen element.

16. 2. The substrate processing method according to claim 1, wherein the first modifying gas and the second modifying gas are the same gas.

17. For the substrate, (a) supplying a first modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, and allowing the first modifying gas to be adsorbed onto a portion of the substrate; (b) supplying a source gas containing a metal element and a halogen element, the source gas being inhibited from being adsorbed by the first modifying gas adsorbed on the substrate, and allowing the source gas to be adsorbed on another part of the substrate, thereby forming an adsorption layer of molecules of the source gas; (c) supplying a second modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, and reacting a portion of the adsorption layer with the second modifying gas; (d) supplying a reaction gas, which is a nitrogen-containing gas or a reducing gas, to cause a substitution reaction between another portion of the adsorption layer and the reaction gas; A manufacturing method of a semiconductor device, in which a cycle of performing the above steps in this order is performed a predetermined number of times.

18. A first modifying gas supply system that supplies a first modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, to a substrate; a second modifying gas supply system that supplies a second modifying gas to the substrate, the second modifying gas being one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas; a source gas supply system that supplies a source gas containing a metal element and a halogen element, the source gas being inhibited from being adsorbed by the first modifying gas adsorbed on the substrate, to the substrate; a reactive gas supply system that supplies a reactive gas, which is a nitrogen-containing gas or a reducing gas, to the substrate; a control unit configured to control the first modifying gas supply system, the second modifying gas supply system, the raw material gas supply system, and the reactive gas supply system so that a cycle of sequentially executing the following processes is performed a predetermined number of times on the substrate: (a) a process of supplying the first modifying gas to adsorb the first modifying gas onto a portion of the substrate; (b) a process of supplying the raw material gas to adsorb the raw material gas onto another portion of the substrate to form an adsorption layer of molecules of the raw material gas; (c) a process of supplying the second modifying gas to react with the second modifying gas; and (d) a process of supplying the reactive gas to cause a substitution reaction between the other portion of the adsorption layer and the reactive gas. A substrate processing apparatus comprising:

19. For the substrate, (a) supplying a first modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, and allowing the first modifying gas to be adsorbed onto a portion of the substrate; (b) supplying a source gas containing a metal element and a halogen element, the source gas being inhibited from being adsorbed by the first modifying gas adsorbed on the substrate, and allowing the source gas to be adsorbed on another part of the substrate, thereby forming an adsorption layer of molecules of the source gas; (c) supplying a second modifying gas, which is one of hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, chlorine gas, fluorine gas, nitrogen trifluoride gas, and tungsten hexafluoride gas, and reacting a portion of the adsorption layer with the second modifying gas; (d) supplying a reaction gas, which is a nitrogen-containing gas or a reducing gas, to cause a substitution reaction between another portion of the adsorption layer and the reaction gas; a program that causes a computer to execute a procedure of performing a cycle of executing the above steps in this order a predetermined number of times in a substrate processing apparatus.

Images