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

Abstract

This invention relates to a substrate processing method, a semiconductor device manufacturing method, a process, and a substrate processing apparatus. The objective of this invention is to provide a technique that improves the stepped coverage of a film formed on a substrate. This invention forms an oxide film containing a predetermined element on a substrate by performing the following steps (a), (b), and (c) a predetermined number of times: (a) forming a first layer containing the predetermined element and a halogen element on the substrate by supplying the substrate with a first raw material containing the predetermined element and a halogen element; (b) forming a second layer containing the predetermined element on the substrate by supplying the substrate with the first layer formed with a second raw material containing the predetermined element and a unique amine group bonded to the predetermined element in one molecule; and (c) oxidizing the second layer by supplying the substrate with the second layer formed with an oxidant.

Description

Technical Field

[0001] The present invention relates to a substrate processing method, a semiconductor device manufacturing method, a program and a substrate processing device. Prior Art

[0002] One of the steps in manufacturing a semiconductor device is to form a film on a substrate (see, for example, Patent Document 1). [Prior Art Literature] [Patent Document]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2021-39970 Summary of the Invention

[0004] (Problems that the invention aims to solve)

[0005] The present invention provides a technology for improving the step coverage of a film formed on a substrate. (Technical means to solve the problem)

[0006] According to one aspect of the present invention, a technique is provided for forming an oxide film containing a predetermined element on a substrate by executing a cycle comprising the following steps (a), (b), and (c) a predetermined number of times: (a) supplying a first raw material containing a predetermined element and a halogen element to a substrate, thereby forming a first layer containing the predetermined element and capped with the halogen element on the substrate; (b) supplying a second raw material containing the predetermined element and a single amino group bonded to the predetermined element in one molecule to the substrate on which the first layer is formed, thereby forming a second layer containing the predetermined element on the substrate; and (c) supplying an oxidizing agent to the substrate on which the second layer is formed, thereby oxidizing the second layer. (Compared with the efficacy of previous technologies)

[0007] According to the present invention, the step coverage of a film formed on a substrate can be improved. Simple diagram description

[0008] FIG1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in one embodiment of the present invention, showing a portion of the processing furnace 202 in a vertical cross-sectional view. FIG2 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in one embodiment of the present invention, showing a portion of the processing furnace 202 in a cross-sectional view taken along line AA of FIG1 . FIG3 is a schematic diagram of the structure of a controller 121 of a substrate processing apparatus suitable for use in one embodiment of the present invention, showing a control system of the controller 121 in the form of a block diagram. FIG. 4 is a diagram showing a substrate processing sequence in one embodiment of the present invention. Figure 5(a) shows the adsorption position of a first raw material supplied to a wafer within a concave structure of the wafer. Figure 5(b) shows the adsorption position of a second raw material supplied to a wafer within the concave structure of the wafer after the supply of the first raw material begins. Figure 5(c) shows the oxide film formed within the concave structure of the wafer by executing a cycle comprising a first raw material supply step, a second raw material supply step, and an oxidation step a predetermined number of times. FIG. 6 is a diagram showing an example of an oxide film formed in a concave structure of a wafer. FIG. 7 is a diagram showing another example of an oxide film formed in a concave structure of a wafer. Implementation Method

[0009] <One aspect of the present invention> The following describes one aspect of the present invention primarily with reference to Figures 1 to 7 . The figures used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the figures do not necessarily correspond to actual dimensions. Furthermore, the dimensional relationships and ratios of the elements shown in multiple figures do not necessarily correspond to actual dimensions.

[0010] (1) Configuration of substrate processing apparatus As shown in Figure 1, a processing furnace 202 of a substrate processing apparatus includes a heater 207 serving as a temperature adjustment unit (heating unit). Heater 207 is cylindrical and vertically supported by a retaining plate. Heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas through heat.

[0011] Inside heater 207, reaction tube 203 is concentrically arranged with heater 207. 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 top and an open bottom. Below reaction tube 203, manifold 209 is concentrically arranged with reaction tube 203. Manifold 209 is made of a metal material such as stainless steel (SUS) and has a cylindrical shape with open top and bottom ends. The upper end of manifold 209 engages with the lower end of reaction tube 203, supporting reaction tube 203. An O-ring 220a is provided between manifold 209 and reaction tube 203 as a sealing member. Like heater 207, reaction tube 203 is mounted vertically. The processing vessel (reaction vessel) primarily consists of reaction tube 203 and manifold 209. A processing chamber 201 is formed in the hollow portion of the processing container. The processing chamber 201 is configured to accommodate a wafer 200 as a substrate. The wafer 200 is processed in the processing chamber 201 .

[0012] Within processing chamber 201, nozzles 249a and 249b, serving as the first and second supply units, are respectively disposed through the sidewalls of manifold 209. Nozzles 249a and 249b are also referred to as the first and second nozzles, respectively. Nozzles 249a and 249b are made of a heat-resistant material such as quartz or SiC. Nozzles 249a and 249b are each configured as a common nozzle for supplying multiple gases.

[0013] Gas supply pipes 232a and 232b, serving as the first and second pipes, are connected to nozzles 249a and 249b, respectively. Gas supply pipes 232a and 232b are configured as shared pipes for supplying multiple gases. Mass flow controllers (MFCs) 241a and 241b, which are flow controllers (flow control units), and valves 243a and 243b, which are on-off valves, are installed in order, starting from the upstream side of the gas flow. Gas supply pipes 232c and 232d are connected to gas supply pipe 232a downstream of valve 243a. MFCs 241c and 241d and valves 243c and 243d are installed in order, starting from the upstream side of the gas flow. Gas supply pipe 232e is connected to gas supply pipe 232b downstream of valve 243b. On the gas supply pipe 232e, MFC 241e and valve 243e are respectively installed in order from the upstream side of the gas flow. The gas supply pipes 232a~232e are made of metal materials such as SUS.

[0014] As shown in Figure 2, nozzles 249a and 249b are positioned in the annular space between the inner wall of the reaction tube 203 and the wafers 200, extending vertically upward from the bottom to the top of the inner wall of the reaction tube 203, in the direction in which the wafers 200 are arranged. Specifically, nozzles 249a and 249b are positioned along the wafer arrangement area, horizontally surrounding the area to the sides of the wafers 200. Gas supply holes 250a and 250b are provided on the sides of the nozzles 249a and 249b, respectively, for supplying gas. These gas supply holes 250a and 250b open toward the center of the wafers 200 when viewed from above, allowing gas to be supplied to the wafers 200. A plurality of gas supply holes 250a and 250b are provided, extending from the bottom to the top of the reaction tube 203.

[0015] A modifier and a first raw material serving as a film-forming agent are supplied into the processing chamber 201 through the gas supply pipe 232 a via the MFC 241 a , the valve 243 a , and the nozzle 249 a .

[0016] The film-forming agent and the oxidizing agent are supplied into the processing chamber 201 from the gas supply pipe 232 b via the MFC 241 b , the valve 243 b , and the nozzle 249 b .

[0017] The second raw material serving as a film-forming agent is supplied into the processing chamber 201 from the gas supply pipe 232 c via the MFC 241 c , the valve 243 c , and the nozzle 249 a .

[0018] Inert gas is supplied from gas supply pipes 232d and 232e via MFCs 241d and 241e, valves 243d and 243e, gas supply pipes 232a and 232b, and nozzles 249a and 249b into the processing chamber 201. The inert gas functions as a purge gas, carrier gas, or dilution gas.

[0019] The first raw material supply system primarily consists of gas supply pipe 232a, MFC 241a, and valve 243a. The oxidant supply system primarily consists of gas supply pipe 232b, MFC 241b, and valve 243b. The second raw material supply system primarily consists of gas supply pipe 232c, MFC 241c, and valve 243c. The inert gas supply system primarily consists of gas supply pipes 232d and 232e, MFCs 241d and 241e, and valves 243d and 243e. Valves connecting the gas supply pipes constituting each of the above-mentioned supply systems may also be included in the corresponding supply system.

[0020] Any or all of the various supply systems described above may be configured as a centralized supply system 248, integrating valves 243a-243e, MFCs 241a-241e, and the like. The centralized supply system 248 is connected to each of the gas supply pipes 232a-232e and controls the supply of various substances (gases) into the gas supply pipes 232a-232e via the controller 121 (described later). Specifically, the controller 121 controls the opening and closing of the valves 243a-243e and the flow rate adjustment by the MFCs 241a-241e. The centralized supply system 248 is configured as an integrated or split centralized unit. The gas supply pipes 232a-232e and the like can be attached and detached as a unit, and the centralized supply system 248 can be repaired, replaced, or expanded as a unit.

[0021] An exhaust port 231a for exhausting the atmosphere within the processing chamber 201 is located below the sidewall of the reaction tube 203. As shown in Figure 2, the exhaust port 231a is positioned so as to face (or be face to face with) the nozzles 249a and 249b (gas supply holes 250a and 250b) while sandwiching the wafers 200, as viewed from above. The exhaust port 231a extends from the bottom to the top of the sidewall of the reaction tube 203, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is connected to a vacuum pump 246, which serves as a vacuum exhaust system, via a pressure sensor 245, which serves as a pressure detector (pressure detection unit) for detecting the pressure within the processing chamber 201, and an APC (Auto Pressure Controller) valve 244, which serves as a pressure regulator (pressure adjustment unit). APC valve 244 is configured to open and close the valve depending on the operating state of vacuum pump 246, thereby enabling and disabling vacuum evacuation within processing chamber 201. Furthermore, depending on the operating state of vacuum pump 246, the valve opening is adjusted based on pressure information detected by pressure sensor 245, thereby regulating the pressure within processing chamber 201. The exhaust system primarily comprises exhaust pipe 231, APC valve 244, and pressure sensor 245. Vacuum pump 246 can also be considered as part of the exhaust system.

[0022] Below the manifold 209, a sealing cap 219 is installed, serving as a furnace port cover that hermetically seals the lower opening of the manifold 209. The sealing cap 219 is made of a metal material such as SUS and is formed into a disc shape. An O-ring 220b, serving as a sealing member and contacting the lower end of the manifold 209, is installed on the top surface of the sealing cap 219. Below the sealing cap 219, a rotation mechanism 267 is installed to rotate the wafer boat 217, described later. The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cap 219 and is connected to the wafer boat 217. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the wafer boat 217. The sealing cap 219 is configured to be vertically elevated by the wafer boat elevator 115, a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transport device (transport mechanism) that carries (transports) the wafers 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219 .

[0023] A gate 219s, serving as a furnace cover, is installed below the manifold 209. This gate 219s airtightly seals the lower opening of the manifold 209 when the sealing cover 219 is lowered and the wafer boat 217 is removed from the processing chamber 201. The gate 219s is made of a metal material, such as SUS, and is formed into a disc shape. An O-ring 220c, serving as a sealing member and contacting the lower end of the manifold 209, is installed on the top surface of the gate 219s. The opening and closing motion (lifting, rotating, etc.) of the gate 219s is controlled by the gate opening and closing mechanism 115s.

[0024] The wafer boat 217, serving as a substrate support, is configured to support multiple wafers 200, for example, 25 to 200, in a horizontal position, aligned with their centers, and arranged vertically in multiple stages. The wafer boat 217 is made of a heat-resistant material such as quartz or SiC. Heat shields 218, also made of a heat-resistant material such as quartz or SiC, are supported in multiple stages at the bottom of the wafer boat 217.

[0025] A temperature sensor 263 is installed within the reaction tube 203 as a temperature detector. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature within the processing chamber 201 can be adjusted to achieve the desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0026] As shown in Figure 3, the control unit (control means), or controller 121, is comprised of a computer and includes a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, a memory device 121c, and an I / O port 121d. RAM 121b, memory device 121c, and I / O port 121d are configured to exchange data with CPU 121a via an internal bus 121e. An input / output device 122, such as a touch panel, is connected to controller 121. An external memory device 123 can also be connected to controller 121. Furthermore, the substrate processing apparatus can be configured with a single controller or multiple controllers. In other words, the control for executing the processing sequence described below can be performed using a single controller or multiple controllers. Furthermore, multiple control units may form a control system interconnected via a wired or wireless communication network, or the control system as a whole may be used to control the processing sequence described below. The term "control unit" used in this specification refers to a single control unit, multiple control units, or a control system composed of multiple control units.

[0027] The memory device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), or an SSD (Solid State Drive). The memory device 121c readablely records and stores a control program for controlling the operation of the substrate processing apparatus, or a process recipe that records the procedures and conditions for the substrate processing described later. The process recipe functions as a program, which is a combination of procedures that achieve a predetermined result by causing the processing apparatus to execute the various procedures for the substrate processing described later, using the controller 121. Hereinafter, the general term for process recipes, control programs, etc. is also referred to as a program. Furthermore, the process recipe is also referred to as a recipe. In this specification, the term "program" refers to the case where it contains only the recipe itself, the case where it contains only the control program itself, or the case where it contains both. The RAM 121b is a memory area (work area) that temporarily stores programs or data read by the CPU 121a.

[0028] The I / O port 121d is connected to the MFCs 241a to 241e, valves 243a to 243e, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, gate switch mechanism 115s, etc.

[0029] The CPU 121a is configured to read and execute a control program from the memory device 121c, and to read a recipe from the memory device 121c in response to input of an operation command from the input / output device 122. Based on the contents of the read recipe, the CPU 121a is configured to control the flow rate adjustment of various substances (gases) using the MFCs 241a-241e, the opening and closing of the valves 243a-243e, the opening and closing of the APC valve 244 and the pressure adjustment performed by the APC valve 244 using the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment of the heater 207 using the temperature sensor 263, the rotation and rotation speed adjustment of the wafer boat 217 by the rotation mechanism 267, the lifting and lowering of the wafer boat 217 by the wafer elevator 115, and the opening and closing of the gate 219s by the gate opening and closing mechanism 115s.

[0030] The controller 121 can be constructed by installing the above-mentioned program recorded and stored by the external memory device 123 into the computer. The external memory device 123 includes, for example, magnetic disks such as HDD, optical disks such as CD, magneto-optical disks such as MO, USB memory, semiconductor memory such as SSD, etc. The memory device 121c or the external memory device 123 is constructed as a recording medium that can be read by the computer. Hereinafter, as a general term, these are referred to as recording media. When the term recording medium is used in this specification, it refers to the case where only the memory device 121c is included, the case where only the external memory device 123 is included, or the case where both are included. Moreover, the provision of programs to the computer can also be carried out without using the external memory device 123, but using communication means such as the Internet or dedicated lines.

[0031] (2) Substrate processing steps As one of the steps in manufacturing semiconductor devices using the aforementioned processing apparatus, a method for processing a substrate, specifically, a processing sequence for forming an oxide film on a wafer 200 serving as a substrate, will be described primarily using Figures 4 to 7 . In this embodiment, the description will be based on an example of a wafer 200 having a concave structure 300, such as a three-dimensional groove, trench, or hole, formed on its surface. In the following description, the operations of the various components comprising the substrate processing apparatus are controlled by a controller 121.

[0032] In the processing sequence of this embodiment, an oxide film containing a predetermined element is formed on the substrate 200 by executing the cycle including the following steps (a), (b), and (c) a predetermined number of times (n times, where n is an integer greater than or equal to 1 or 2): (a) step A of supplying a first raw material containing a predetermined element and a halogen element to the substrate 200, thereby forming a first layer containing a predetermined element capped by the halogen element on the substrate 200; (b) step B of forming a second layer containing the predetermined element on the substrate 200 by supplying a second raw material containing the predetermined element and an amine group bonded to the predetermined element in one molecule to the substrate 200 on which the first layer is formed; and (c) Step C of oxidizing the second layer by supplying an oxidizing agent to the substrate 200 on which the second layer is formed.

[0033] In this embodiment, the predetermined elements contained in the first and second raw materials are the main elements constituting the second layer and the oxide film formed on the wafer 200. Hereinafter, as an example, a case where a Si film is formed as a base on the surface of the wafer 200 will be described.

[0034] In this specification, for convenience, the above-mentioned processing sequence is also represented as follows. The same notation is also used in the following description of other aspects such as the modified examples.

[0035] (1st raw material → rinse → 2nd raw material → rinse → oxidant → rinse) xn

[0036] When the term "wafer" is used in this specification, it refers to both the wafer itself and the laminated product of the wafer and a predetermined layer or film formed on its surface. When the term "wafer surface" is used in this specification, it refers to both the surface of the wafer itself and the surface of a predetermined layer formed on the wafer. When "a predetermined layer is formed on the wafer" is used in this specification, it refers to both forming the predetermined layer directly on the surface of the wafer itself and forming the predetermined layer on top of a layer formed on the wafer. The term "substrate" used in this specification has the same meaning as the term "wafer."

[0037] The term "agent" as used in this specification includes at least one of a gaseous substance and a liquid substance. A gaseous substance includes a mist-like substance. For example, each of the first raw material, the second raw material, and the oxidizing agent may include a gaseous substance, a liquid substance such as a mist-like substance, or both.

[0038] The term "layer" used in this specification includes at least one of a continuous layer and a discontinuous layer. For example, the first layer and the second layer may each include a continuous layer, a discontinuous layer, or both.

[0039] In this specification, when describing the situations in which the first raw material, the second raw material and the oxidant adsorb and react on the surface of the wafer 200 respectively, it includes not only the situations in which they adsorb and react on the wafer surface in an undecomposed state, but also the situations in which the intermediates generated by the decomposition and the detachment of their ligands adsorb and react on the surface of the wafer 200.

[0040] (Wafer filling and wafer boat loading) When multiple wafers 200 are loaded onto the wafer boat 217 (wafer filling), the gate 219s is moved by the gate opening and closing mechanism 115s, opening the lower end of the manifold 209 (gate opening). Then, as shown in Figure 1 , the wafer boat 217, supporting the multiple wafers 200, is lifted by the boat elevator 115 and moved into the processing chamber 201 (wafer loading). In this state, the sealing cap 219 seals the lower end of the manifold 209 via the O-ring 220b. In this manner, the wafers 200 are prepared within the processing chamber 201.

[0041] (Pressure adjustment and temperature adjustment) After the wafer boat is loaded, the processing chamber 201, i.e., the space containing the wafers 200, is evacuated (decompressed) by the vacuum pump 246 to the desired pressure (vacuum level). The pressure within the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is controlled based on the measured pressure information. Furthermore, the heater 207 heats the wafers 200 within the processing chamber 201 to the desired processing temperature. The power level to the heater 207 is controlled (temperature adjustment) based on the temperature information detected by the temperature sensor 263, so that the desired temperature distribution within the processing chamber 201 is achieved. Furthermore, the rotation of the wafers 200 is initiated by the rotation mechanism 267. The evacuation of the processing chamber 201, the heating of the wafers 200, and the rotation of the wafers 200 are all continuously performed until at least the end of processing of the wafers 200.

[0042] (Film forming treatment) Then, follow the steps A, B, and C in sequence.

[0043] [Step A] In this step, a first raw material including a predetermined element and a halogen element is supplied to the wafer 200 in the processing chamber 201 .

[0044] Specifically, valve 243a is opened to allow the first raw material to flow into gas supply pipe 232a. The first raw material is supplied into processing chamber 201 through nozzle 249a, with its flow rate regulated by MFC 241a, and then exhausted through exhaust port 231a. At this point, the first raw material is supplied to wafer 200 (first raw material supply). Alternatively, valves 243d and 243e can be opened to supply an inert gas into processing chamber 201 through nozzles 249a and 249b, respectively.

[0045] As the processing conditions when supplying the first raw material in this step, the following can be exemplified: Processing temperature: 350~700°C, preferably 500~600°C; Processing pressure: 1~10000Pa, preferably 10~1333Pa; First raw material supply flow rate: 0.01~3slm, preferably 0.1~1slm; First raw material supply time: 10 to 120 seconds, preferably 20 to 60 seconds; Inert gas supply flow rate (per gas supply pipe): 0~10slm. However, the processing pressure in this step is preferably lower than the processing pressure in step B. Furthermore, the partial pressure of the first raw material supplied to wafer 200 in this step is preferably lower than the partial pressure of the second raw material supplied to wafer 200 in step B. Furthermore, from the perspective of increasing processing speed, it is particularly preferred that the processing temperature in any of steps A-C be substantially the same. Furthermore, when a raw material containing bonds between predetermined elements is used as the first raw material, in this step, the first raw material is preferably supplied to wafer 200 under processing conditions that cause the bonds between the predetermined elements contained in the first raw material to break in the gas phase. These processing conditions include at least one of the processing temperature, processing pressure, the presence or absence of plasma excitation, and the amount of energy imparted during the plasma excitation.

[0046] Furthermore, in this specification, numerical ranges such as "350-700°C" indicate that the range includes both lower and upper limits. Therefore, for example, "350-700°C" means "above 350°C and below 700°C." The same applies to other numerical ranges. Furthermore, in this specification, the term "process temperature" refers to the temperature of wafer 200 or the temperature within process chamber 201, and the term "process pressure" refers to the pressure within process chamber 201, that is, the pressure in the space containing wafer 200. Furthermore, when the supply flow rate includes 0 slm, 0 slm indicates that no gas is being supplied. This applies to the following descriptions as well.

[0047] By supplying a first raw material containing a predetermined element and a halogen element to the wafer 200 under the aforementioned processing conditions, the first raw material can be adsorbed onto the surface of the wafer 200, forming a first layer containing the predetermined element and having its surface capped by the halogen element (see FIG. 5( a )). Specifically, under the aforementioned processing conditions, the bonds between the predetermined element and the halogen element in the first raw material can be partially severed, allowing the predetermined element with unconnected bonds to adsorb onto adsorption sites on the surface of the wafer 200, thereby forming the first layer. Furthermore, when using a raw material containing bonds between the predetermined elements as the first raw material, under the aforementioned processing conditions, the bonds between the predetermined elements contained in the first raw material can be severed, allowing the predetermined element with unconnected bonds to adsorb onto adsorption sites on the surface of the wafer 200, thereby forming the first layer.

[0048] Furthermore, when the surface of wafer 200 is composed of an oxide film, capping sites such as OH capping exist on the surface of wafer 200. By forming the first layer in this step, at least a portion of the adsorption sites on the surface of wafer 200 is occupied by the halogen-capped first layer. Furthermore, in step C, described later, by supplying an oxidizing agent to wafer 200, capping sites such as OH capping are formed on the outermost surface of wafer 200, which serve as adsorption sites in steps A and B.

[0049] Under the above-described processing conditions, a first layer containing a predetermined element and capped with a halogen element (halogen capping) can be discontinuously formed on at least a portion of the upper and inner surfaces of the concave structure 300 (specifically, the inner side and bottom surfaces of the concave structure 300). Specifically, the first raw material (the predetermined element) can be preferentially adsorbed on the opening 301 side of the concave structure 300 to form the first layer (see Figure 5(a)). In other words, the first layer can be formed such that the density of the first layer formed on the upper side of the opening 301 side of the concave structure 300 (the side surface of the opening of the concave structure 300) is greater than the density of the first layer formed on the lower side of the deep side 302 (the bottom surface of the opening of the concave structure 300). In this specification, the term "layer density" on the upper and inner surfaces of the concave structure 300 can be considered synonymous with, for example, the number of adsorbed elements, such as a predetermined element, bonded with a halogen element (i.e., terminated with a halogen element), per unit area of ​​the inner surface of the concave structure 300, or the average thickness of the layer per unit area of ​​the inner surface of the concave structure 300. Furthermore, the first layer can be formed discontinuously across the entire inner surface of the concave structure 300.

[0050] Furthermore, if the processing temperature is lower than 350°C, chemical adsorption onto the inner surface of the concave structure 300 is difficult to occur, and it may be difficult to form the first layer at a practical speed. By setting the processing temperature to 350°C or higher, the first layer can be formed on the inner surface of the concave structure 300 at a practical speed.

[0051] Furthermore, when a raw material containing bonds between predetermined elements is used as the first raw material, if the treatment temperature is less than 500°C, the bonds between the predetermined elements contained in the first raw material will not be broken in the gas phase, and this may make it difficult for the predetermined elements to be adsorbed onto the inner surface of the concave structure 300. By setting the treatment temperature to 500°C or higher, the bonds between the predetermined elements contained in the first raw material are broken, thereby promoting the adsorption of the predetermined elements onto the inner surface of the concave structure 300.

[0052] If the treatment temperature exceeds 700°C, the first raw material undergoes excessive thermal decomposition in the gas phase, and the predetermined element tends to be locally deposited near the upper end of the inner surface of the concave structure 300, making it difficult to form a first layer having a desired thickness distribution on the sidewalls and bottom of the inner surface of the concave structure 300. By setting the treatment temperature below 700°C, a first layer having a desired thickness distribution can be formed on the sidewalls and bottom of the inner surface. Setting the treatment temperature below 600°C makes it easier to form a first layer having a desired thickness distribution on the sidewalls and bottom of the inner surface of the concave structure 300. Furthermore, while maintaining the same treatment temperature in step C described later, setting the treatment temperature below 600°C suppresses excessive thermal decomposition of the oxidant supplied in step C, thereby achieving a practical film formation rate.

[0053] In the first layer, the halogen capping formed on the surface suppresses (hinders) the adsorption of the second raw material supplied in step B, or at least one of the predetermined elements contained in the second raw material. In other words, the first layer serves as an adsorption-blocking layer that blocks the adsorption of the second raw material or at least one of the predetermined elements contained in the second raw material onto the first layer.

[0054] As the first raw material, a gas containing a predetermined element and a halogen element can be used. When the predetermined element is Si, a halosilane gas can be used as the first raw material. As the halogen element, at least one of chlorine (Cl), fluorine (F), bromine (Br), and iodine (I) can be used.

[0055] As the first raw material, a chlorosilane gas such as tetrachlorosilane (SiCl 4) gas, monochlorosilane (SiH 3Cl) gas, dichlorosilane (SiH 2Cl 2) gas, or trichlorosilane (SiHCl 3) gas can be used. These gases must not contain any Si bonds (i.e., bonds between predetermined elements) within one molecule. As the first raw material, in addition to chlorosilane-based gases, for example, fluorosilane-based gases such as tetrafluorosilane (SiF4) gas and difluorosilane (SiH2F2) gas; bromosilane-based gases such as tetrabromosilane (SiBr4) gas and dibromosilane (SiH2Br2) gas; and iodosilane-based gases such as tetraiodosilane (SiI4) gas and diiodosilane (SiH2I2) gas can be used. Gases that do not contain any Si-to-Si bonds (i.e., any bonds between any given elements) within a single molecule are required. Among these gases, gases that do not contain any hydrogen (H) within a single molecule, such as SiCl4 gas, SiF4 gas, SiBr4 gas, and SiI4 gas, are preferred as the first raw material.

[0056] As the first raw material, chlorosilane-based gases such as hexachlorodisilane (Si2Cl6) gas, octachlorotrisilane (Si3Cl8) gas, monochlorodisilane (Si2H5Cl) gas, dichlorodisilane (Si2H4Cl2) gas, trichlorodisilane (Si2H3Cl3) gas, tetrachlorodisilane (Si2H2Cl4) gas, monochlorotrisilane (Si3H5Cl) gas, and dichlorotrisilane (Si3H4Cl2) gas can be used. These gases must contain Si atoms bonded together (i.e., bonds between specific elements) within a single molecule. Alternatively, other halosilane-based gases with molecular structures obtained by replacing Cl atoms in the molecular structure of these chlorosilane-based gases with atoms of other halogen elements can be used as the first raw material. As the first raw material, among these gases, a gas that does not contain H, such as Si 2 Cl 6 gas and Si 3 Cl 8 gas, is preferred.

[0057] As the first raw material, one or more of these can be used.

[0058] As an inert gas, nitrogen (N2) gas, or a rare gas such as argon (Ar), helium (He), neon (Ne), or xenon (Xe) gas can be used. As an inert gas, one or more of these can be used. This applies to the steps described below.

[0059] After the first layer is formed on the surface of wafer 200 (the upper and inner surfaces of concave structures 300), valve 243a is closed to stop the supply of the first raw material into processing chamber 201. Then, the processing chamber 201 is evacuated to remove any remaining gaseous substances. At this point, valves 243d and 243e are opened to supply an inert gas into processing chamber 201 via nozzles 249a and 249b. The inert gas supplied by nozzles 249a and 249b acts as a purge gas, thereby purging (cleaning) the space in which wafer 200 is located, i.e., the interior of processing chamber 201.

[0060] [Step B] After step A is completed, a second raw material containing a predetermined element and an amine group bonded to the predetermined element within a single molecule is supplied to the wafer 200 in the processing chamber 201, i.e., the wafer 200 on which the first layer has been formed on the inner surface of the concave structure 300. In this embodiment, the second raw material containing a predetermined element and an amine group bonded to the predetermined element within a single molecule is supplied.

[0061] Specifically, valve 243c is opened to allow the second raw material to flow into gas supply pipe 232c. The second raw material is supplied into processing chamber 201 through nozzle 249a, with its flow rate regulated by MFC 241c, and exhausted through exhaust port 231a. At this point, the second raw material is supplied to wafer 200 (second raw material supply). Alternatively, valves 243d and 243e can be opened to supply inert gas into processing chamber 201 through nozzles 249a and 249b, respectively.

[0062] As the processing conditions when supplying the second raw material in this step, the following can be exemplified: Processing temperature: 20~700°C, preferably 200~600°C, more preferably 500~600°C; Processing pressure: 1~10000Pa, preferably 10~2666Pa, more preferably 1000~2666Pa; Second raw material supply flow rate: 0.01~4slm, preferably 0.3~1slm; Second raw material supply time: 1 to 60 seconds, preferably 5 to 20 seconds; The other processing conditions are the same as those used when supplying the first raw material in step A. However, this step is performed under processing conditions that allow the predetermined element contained in the second raw material to be adsorbed onto wafer 200 by supplying the second raw material to wafer 200, where the first layer has not yet been formed. The processing conditions herein include at least one of temperature and pressure. Furthermore, the processing pressure in this step is preferably greater than the processing pressure in step A. Furthermore, the partial pressure of the second raw material supplied to wafer 200 in this step is preferably greater than the partial pressure of the first raw material supplied to wafer 200 in step A.

[0063] By supplying a second raw material containing a predetermined element to wafer 200 under the aforementioned processing conditions, the second raw material is primarily adsorbed at locations on the surface of wafer 200 where halogen-terminated portions of the first layer are not formed (i.e., adsorption sites remaining on the surface of wafer 200 without halogen-terminated portions), thereby forming a second layer containing the predetermined element (see FIG5(b)). Specifically, the second layer is formed on wafer 200 by causing amine groups to dissociate from molecules of the second raw material, resulting in unbonded predetermined elements adsorbed at adsorption sites on the surface of wafer 200 where the first layer is not formed. Furthermore, when forming the second layer, the halogen-terminated portions of the first layer react with the amine groups contained in the second raw material, causing at least a portion of the halogen-terminated portions to dissociate from the surface of wafer 200 (the surface of the first layer).

[0064] Here, when the first layer is not formed on the inner surface of the concave structure 300, the uneven supply of the second raw material causes the second layer to form at a slower rate on the surface of the deep portion 302 than on the surface of the opening portion 301, sometimes resulting in a reduction in the step coverage of the second layer. Furthermore, this reduction in the step coverage of the second layer may also reduce the step coverage of the oxide film formed by modifying (oxidizing) the second layer.

[0065] However, as described above, the first layer, which inhibits the adsorption of the second material, is formed so that its density increases at the upper end of the opening side 301 compared to the lower end of the deep side 302 (the bottom surface of the opening of the concave structure 300). Therefore, adsorption of the second material is further suppressed at the opening side 301 compared to the deep side 302. As a result, the effect of the first layer on the opening side 301 on reducing the density of the second layer is greater than the effect of the first layer on the deep side 302 on reducing the density of the second layer. This increases the rate of second layer formation on the deep side 302 relative to the rate of second layer formation on the opening side 301, compared to a case where the first layer is not formed. In other words, by forming the first layer, the thickness distribution of the second layer can be controlled so that the rate of second layer formation on the deep side 302 is increased and the rate of second layer formation on the opening side 301 is decreased, compared to a case where the first layer is not formed. For example, the thickness distribution of the second layer can be controlled in such a way that the formation rate of the second layer on the deep side 302 is greater than the formation rate of the second layer on the opening side 301, or in such a way that the formation rate of the second layer on the deep side 302 is approximately the same as the formation rate of the second layer on the opening side 301.

[0066] Furthermore, in this step, if the processing temperature is below 500°C, it may be difficult for the predetermined element contained in the second raw material to be adsorbed on the inner surface of the concave structure 300, and it may be difficult to form the second layer at a practical speed. In this step, by increasing the processing temperature to a temperature exceeding 500°C, the second layer can be formed on the inner surface of the concave structure 300 at a practical speed.

[0067] Furthermore, if the processing pressure is less than 100 Pa, the second raw material is less likely to be adsorbed onto the inner surface of the concave structure 300, and it may be difficult to form the second layer at a practical speed. By increasing the processing pressure to 100 Pa or higher, the adsorption of the second raw material onto the inner surface of the concave structure 300 is promoted, and the second layer can be formed at a practical speed.

[0068] In this step, the following processing conditions can be set, for example, by setting the processing temperature to a temperature exceeding 500 degrees and the processing pressure to a processing pressure of 100 Pa or more, so that the predetermined element contained in the second raw material can be adsorbed at a practical rate even on the surface of the wafer 200 where the first layer is not formed.

[0069] Furthermore, if the processing temperature exceeds 700°C, the second raw material undergoes excessive thermal decomposition in the gas phase, and the predetermined element tends to be locally and over-deposited near the upper end of the inner surface of the concave structure 300, which may make it difficult to form a second layer with excellent step coverage. By setting the processing temperature below 700°C, a second layer with excellent step coverage can be formed.

[0070] As the second raw material, a gas containing a predetermined element and an amino group bonded to the predetermined element in one molecule can be used. That is, when the predetermined element is Si, an aminosilane-based gas can be used as the second raw material.

[0071] As the second raw material, it is preferred to use a gas containing a predetermined element and a single amine group bonded to the predetermined element within a single molecule. In other words, it is preferred to use a compound represented by the chemical formula AR1X-1R2. Here, A is the predetermined element, R1 is a ligand other than an amine group, R1 is an amine group, and x is the number of chemical bonds of the predetermined element. For example, when the predetermined element is Si, it is preferred that the second raw material be an aminosilane-based gas containing Si and an amine group, wherein one amine group is bonded to each Si element within a single molecule. Furthermore, it is preferred to use a gas containing a predetermined element and a single amine group bonded to the predetermined element within a single molecule, wherein all chemical bonds of the predetermined element other than the bond to the single amine group are bonded to hydrogen. In other words, it is preferred to use a compound represented by the chemical formula AHX-1R. Where A is a given element, R is a unique amine group, and x is the number of chemical bonds of the given element.

[0072] Here, an amine group refers to a functional group consisting of one or two hydrocarbon groups containing one or more carbon atoms coordinated to one nitrogen (N) atom (a functional group in which one or two hydrogen atoms in an amine group represented by NH2 are replaced with hydrocarbon groups containing one or more carbon atoms). When two hydrocarbon groups are coordinated to one nitrogen atom, these two hydrocarbon groups can be the same or different. Hydrocarbon groups can contain single bonds, like alkyl groups, or unsaturated bonds such as double and triple bonds. Amine groups can have a cyclic structure. Amine groups are bonded to the Si atom, the central atom of the aminosilane molecule. Therefore, the amino groups in aminosilanes are also referred to as ligands or amino ligands. In addition to Si and amine groups, aminosilane-based gases can also contain hydrocarbon groups. Hydrocarbon groups can contain single bonds, like alkyl groups, or unsaturated bonds such as double and triple bonds. The hydrocarbon group may also have a cyclic structure. The hydrocarbon group may also be bonded to the Si atom, the central atom of the aminosilane molecule. In this case, the hydrocarbon group in the aminosilane may also be referred to as a ligand or hydrocarbon ligand. When the hydrocarbon group is an alkyl group, it may also be referred to as an alkyl ligand.

[0073] As the second raw material, (dialkylamino)trialkylsilane gas such as (dimethylamino)trimethylsilane ((CH 3) 2NSi(CH 3) 3) gas, diethylaminotrimethylsilane ((C 2H 5) 2NSi(CH 3) 3) gas, diethylaminotriethylsilane ((C 2H 5) 2NSi(C 2H 5) 3) gas, dimethylaminotriethylsilane ((CH 3) 2NSi(C 2H 5) 3) gas, (dialkylamino)trialkylsilane gas such as (diisobutylamino)silane ((C 4H 9) 2NSiH 3) gas, (diisopropylamino)silane ((C 3H 7) 2NSiH 3) gas, (ethylmethylamino)silane (SiH As the second raw material, one or more of these can be used, for example, monoaminosilane gases such as (dimethylamino)silane (SiH3(N(CH3)2)) gas, trimethoxydialkylaminosilane gases such as trimethoxydimethylaminosilane ((CH3)2NSi(OCH3)3) gas, and aminosilane-based gases containing a single amino group bonded to Si. As the second raw material, among these gases, it is preferable to use a gas in which the chemical bond of Si is bonded to H, except for the chemical bond with the only amino group, such as ((C 4 H 9) 2NSiH 3) gas, ((C 3 H 7) 2NSiH 3) gas, (SiH 3(N(CH 3)(C 2H 5))) gas, and (SiH 3(N(CH 3) 2)) gas.

[0074] Furthermore, as the second raw material, bis(dialkylamino)dialkylsilane gas such as bis(dimethylamino)dimethylsilane ([(CH 3) 2N] 2Si(CH 3) 2) gas, bis(dialkylamino)alkylsilane gas such as bis(dimethylamino)methylsilane ([(CH 3) 2N] 3SiCH 3) gas, bis(dialkylamino)silane gas such as bis(diethylamino)silane ([(C 2H 5) 2N] 2SiH 2) gas, bis(monoalkylamino)silane gas such as bis(tert-butylamino)silane ([(C 4H 9)NH] 2SiH 2) gas, ...ethylamino)silane ([(C 2H 5) 2N] 2SiH 2) gas, bis(diethylamino)silane ([(C 2H 5) 2N] 2SiH 2) gas, bis(diethylamino)silane ([(C 2H 5) 2N] 2SiH 2) gas, bis(dimethylamino)silane ([(CH 3) 2N] As the second raw material, one or more of the following may be used: tetrakis(dialkylamino)silane gases such as tetrakis(dimethylamino)silane ([(CH₃)₂N]₄Si) gas, and tetrakis(dialkylamino)silane gases such as tetrakis(dimethylamino)silane ([(CH₃)₂N]₄Si) gas; and aminosilane-based gases containing multiple amine groups bonded to Si.

[0075] After the second layer is formed on the surface of wafer 200 (the inner surface of recess 300), valve 243c is closed to stop the supply of raw materials into processing chamber 201. Then, the interior of processing chamber 201 is evacuated to remove any remaining gaseous substances. At this point, valves 243d and 243e are opened to supply an inert gas into processing chamber 201 through nozzles 249a and 249b. The inert gas supplied by nozzles 249a and 249b acts as a purge gas, thereby purging (cleaning) the space where wafer 200 is located, i.e., the interior of processing chamber 201.

[0076] [Step C] After step B is completed, an oxidant is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 on which the second layer has been formed on the inner surface of the concave structure 300, to oxidize the second layer.

[0077] Specifically, valve 243b is opened to allow the oxidant to flow into gas supply pipe 232b. The oxidant is supplied into processing chamber 201 through nozzle 249b at a controlled flow rate by MFC 241b and exhausted through exhaust port 231a. At this point, the oxidant is supplied to wafer 200 (oxidant supply). Alternatively, valves 243d and 243e can be opened to supply inert gas into processing chamber 201 through nozzles 249a and 249b, respectively.

[0078] As the treatment conditions when supplying the oxidizing agent in this step, the following can be exemplified: Processing temperature: 20~700°C, preferably 200~600°C, more preferably 500~600°C; Processing pressure: 100~10000Pa, preferably 1000~10000Pa; Oxidant supply flow rate: 0.1~20slm, preferably 1~10slm; Oxidant supply time: 1 to 120 seconds, preferably 3 to 15 seconds; The other processing conditions are the same as those when the first raw material is supplied in step A. In this step, it is preferred to use a gas that is not plasma excited (non-plasma gas).

[0079] By supplying an oxidant to wafer 200 under the aforementioned processing conditions, at least a portion of the second layer formed on the inner surface of recessed structure 300 reacts with the oxidant and becomes oxidized. As a result, a third layer, serving as an oxide layer of the second layer, is formed on the inner surface of recessed structure 300. The third layer contains a predetermined element. During the formation of the third layer, at least a portion of impurities such as halogen elements contained in the second layer is released from the second layer as a gaseous substance during the oxidation reaction of the third layer and exhausted from processing chamber 201. This results in the third layer containing less impurities such as halogen elements than the second layer formed in step B.

[0080] As the oxidizing agent, an oxygen (O)-containing gas (O-containing substance) can be used. Examples of the O-containing gas include oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO2) gas, carbon monoxide (CO) gas, and carbon dioxide (CO2) gas. As the oxidizing agent, one or more of these can be used. Furthermore, a gas containing O and H (a substance containing O and H) can be used as an oxidizing agent. Examples of the O and H-containing gas include water vapor (H2O) gas, hydrogen peroxide (H2O2) gas, H2 gas + O2 gas, and H2 gas + O3 gas. In other words, an O-containing gas + H-containing gas can also be used as the O and H-containing gas. In this case, deuterium (2H2) gas can be used instead of H2 gas as the H-containing gas. One or more of these can be used as the oxidizing agent. For example, when the aminosilane-based gas described above is used as the second raw material and an O-containing gas or an O- and H-containing gas is used as the oxidizing agent, a silicon oxide layer (SiO layer) is formed as the third layer on the surface of the wafer 200.

[0081] Furthermore, the parallel description of "H2 gas + O2 gas" in this specification refers to a mixed gas of H2 gas and O2 gas. When supplying a mixed gas, the two gases can be mixed in a supply pipe (pre-mixed) before being supplied to the processing chamber 201. Alternatively, the two gases can be supplied to the processing chamber 201 from separate supply pipes and then mixed in the processing chamber 201 (post-mixed).

[0082] As the oxidant, it is preferred to use an O-containing gas that does not contain H, such as O2 gas or O3 gas, among the above-mentioned gases.

[0083] Furthermore, when using an oxygen-containing gas that is easily thermally decomposed as an oxidizing agent, if the treatment temperature exceeds a specific temperature (e.g., 600°C), the oxidizing agent may thermally decompose excessively, reducing its oxidizing power and making it difficult to oxidize the second layer. By keeping the treatment temperature below the specific temperature (e.g., 600°C), the second layer can be oxidized even when using such an oxidizing agent.

[0084] After the second layer formed on the surface of wafer 200 (the inner surface of concave structure 300) is transformed into the third layer, valve 243b is closed to stop the supply of oxidant into processing chamber 201. Then, processing chamber 201 is evacuated to remove any remaining gaseous substances. At this point, valves 243d and 243e are opened to supply inert gas into processing chamber 201 through nozzles 249a and 249b. The inert gas supplied by nozzles 249a and 249b acts as a purge gas, thereby purging (cleaning) the space where wafer 200 is located, i.e., the interior of processing chamber 201.

[0085] [Implement a set number of times] By asynchronously, or in other words, performing the above-described steps A-C in sequence n times (n is an integer greater than or equal to 1 or 2), an oxide film having a desired composition can be formed on the surface of the wafer 200 (the inner surface of the concave structure 300) (see FIG5(c)). Furthermore, the number of cycles n is defined as the number of times the interior of the concave structure 300 is filled with the oxide film, thereby filling the interior of the concave structure 300 with the oxide film. For example, when the above-described gas containing Si and amine groups is used as the second raw material, a silicon oxide film (SiO film) is formed on the surface of the wafer 200. The above-described cycle is preferably repeated multiple times. Specifically, the thickness of the third layer formed in each cycle is preferably made thinner than the desired film thickness, and the above-described cycle is repeated multiple times until the oxide film formed by stacking the third layer reaches the desired film thickness.

[0086] In this aspect, at least one of the supply time, partial pressure, and treatment pressure of the first raw material in step A performed in the mth cycle (m is an integer less than n) can be made different from the corresponding conditions in step A performed in the m+1th cycle. Specifically, based on the film thickness distribution of the oxide film at the end of the mth cycle, at least one of the supply time, partial pressure, and treatment pressure of the first raw material in step A performed in the m+1th cycle can be made different from the corresponding conditions of the first raw material in steps A up to the mth cycle. More specifically, as shown in FIG6 , if the oxide film thickness distribution (aspect ratio) at the end of the mth cycle is greater than the aspect ratio of the concave structure 300 before film formation, the supply time of the first raw material in step A performed in the m+1th cycle can be made longer than that in step A in the mth cycle, the partial pressure of the first raw material in step A performed in the m+1th cycle can be made higher than that in step A in the mth cycle, and the process pressure in step A performed in the m+1th cycle can be made higher than that in step A in the mth cycle. This increases the density of the first layer formed on the upper side of the opening 301, strengthens the film formation-impeding effect of the first layer, and allows the second layer to be formed from the lower end of the deep side 302 (the bottom surface of the opening) toward the side surface of the opening. Consequently, step coverage can be maintained even with a large aspect ratio.

[0087] On the other hand, for example, as shown in FIG7 , if the film thickness distribution (aspect ratio) of the oxide film at the end of the mth cycle is smaller than the aspect ratio of the concave structure 300 before film formation, the supply time of the first raw material in step A performed in the m+1th cycle can be shortened compared to the supply time of the first raw material in step A performed in the m+1th cycle. Alternatively, the partial pressure of the first raw material in step A performed in the m+1th cycle can be lower than the partial pressure of the first raw material in step A performed in the mth cycle. Alternatively, the process pressure in step A performed in the m+1th cycle can be lower than the process pressure in step A performed in the m+1th cycle. This reduces the density of the first layer formed on the upper side of the opening 301, thereby reducing the effect of the first layer hindering film formation. As a result, the formation speed of the second layer can be increased, and the productivity of oxide film formation can be improved.

[0088] In addition, by adjusting at least one of the supply time, partial pressure, and processing pressure of the first raw material in step A, the thickness distribution of the second layer and the oxide film in the depth direction of the concave structure 300 can be controlled.

[0089] (Post-flush and atmospheric pressure restoration) After the film formation process is completed, an inert gas, serving as a purge gas, is supplied into the processing chamber 201 from nozzles 249a and 249b and exhausted from exhaust port 231a. This purges the processing chamber 201, removing any remaining gas or reaction byproducts (post-purge). Subsequently, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (return to atmospheric pressure).

[0090] (Wafer boat unloading and wafer removal) The boat elevator 115 then lowers the sealing cover 219, opening the lower end of the manifold 209. The processed wafers 200, supported by the boat 217, are then unloaded from the lower end of the manifold 209 to the exterior of the reaction tube 203 (boat unloading). After the boat is unloaded, the gate 219s is moved, sealing the lower end opening of the manifold 209 with the gate 219s via the O-ring 220c (gate closing). After the processed wafers 200 are unloaded from the boat 217 (wafer unloading).

[0091] (3) Effects of this aspect According to this aspect, one or more of the following effects can be obtained.

[0092] a) In step B, by using a second raw material containing an amine group (e.g., an aminosilane-based gas), a high film formation rate can be easily achieved compared to the case of using a raw material not containing an amine group (e.g., a halosilane-based gas).

[0093] In step B, by using a second raw material containing only one amine group per molecule that readily reacts with the halogen element capping the first layer, the removal of the halogen element capping the first layer can be minimized. This enhances the inhibitory effect against the adsorption of a given element onto the first layer, compared to using a raw material containing multiple amine groups per molecule. Consequently, the step coverage of the oxide film formed on the inner surface of the concave structure on wafer 200 can be improved.

[0094] By limiting the number of amino groups contained in the second raw material to one per molecule, the amount of amino groups remaining in the second layer can be reduced when the predetermined element contained in the second raw material is adsorbed on the surface of wafer 200 in step B. This reduces the likelihood of amino group-derived impurities (C, N) remaining in the oxide film.

[0095] Furthermore, in step A, by forming the first layer using a raw material containing a predetermined element as the first raw material, the raw material adsorption rate can be increased (increasing the first layer formation rate) compared to forming the first layer using a compound composed solely of a halogen element. This shortens the time required to form the first layer. Furthermore, by forming the first layer containing the predetermined element, the predetermined element contained in the first layer, which functions as an adsorption barrier layer (inhibitor layer) for the second raw material, can also function as part of the oxide film, thereby increasing the oxide film formation rate.

[0096] (b) Step B is performed under the following processing conditions: by supplying the second raw material to wafer 200, which has not yet formed the first layer, the predetermined element contained in the second raw material is adsorbed onto wafer 200. In other words, step B is performed under processing conditions that allow the predetermined element contained in the second raw material to be adsorbed onto wafer 200 even without performing step A, such as processing conditions at a higher temperature and pressure than those under which the predetermined element contained in the second raw material cannot be adsorbed onto the surface of wafer 200 without forming the first layer. Thus, in step B, the predetermined element contained in the second raw material can be adsorbed at adsorption sites on the surface of wafer 200 while the first layer acts to inhibit adsorption of the predetermined element.

[0097] (c) By increasing the partial pressure of the second raw material supplied to wafer 200 in step B to be greater than the partial pressure of the first raw material supplied to wafer 200 in step A, that is, by supplying the second raw material containing the predetermined element and amine groups at a relatively high partial pressure, activation of the second raw material is facilitated, making it easier for the amine groups to be released from the second raw material. This promotes the adsorption of the predetermined element with unconnected bonds onto wafer 200, thereby increasing the film formation rate. The same applies when the process pressure in step B is greater than that in step A.

[0098] By making the partial pressure of the first source material supplied to wafer 200 in step A lower than the partial pressure of the second source material supplied to wafer 200 in step B, that is, by supplying the first source material at a relatively low partial pressure, excessive thermal decomposition of the first source material is suppressed. This prevents a decrease in step coverage due to localized over-deposition of a given element near the upper end of the concave structure 300 on wafer 200. The same applies when the process pressure in step A is lower than the process pressure in step B.

[0099] (d) By using a gas containing bonds between predetermined elements within a single molecule as the first raw material, and severing the bonds between the predetermined elements through thermal decomposition or other means, a highly reactive intermediate containing a halogen element and having unbonded bonds with the predetermined element can be easily generated. This facilitates the formation of a first layer terminated with a halogen element on the surface of wafer 200. In particular, when OH terminations are formed on the oxide film surface, the generation of this intermediate facilitates the formation of the first layer. This is because, when OH terminations are formed on the oxide film surface during step C, these OH terminations function as adsorption sites. Furthermore, the intermediate containing unbonded predetermined elements generated from the first raw material in step A of the next cycle has the high reactivity required to react with these OH terminations and adsorb the predetermined element bonded to the halogen element. In contrast, when a gas containing no bonds between the specified elements within a single molecule is used as the first raw material, Step A may need to be performed under higher temperature and pressure conditions to produce the intermediate having the aforementioned high reactivity. Furthermore, even when a gas containing no specified elements but a halogen element is used as the modifier, higher temperature and pressure conditions may be required to achieve the aforementioned high reactivity.

[0100] (e) In step A, by supplying the first raw material under processing conditions that cause severing of bonds between the predetermined elements in the gas phase, a highly reactive intermediate containing a halogen element and having unconnected bonds with the predetermined elements can be generated in the gas phase. This facilitates the formation of the first layer on the surface of wafer 200 for the same reasons as described above.

[0101] (f) By using a gas containing no H per molecule as the first raw material, the formation of H-terminated gas on the surface of the first layer, which has a low adsorption barrier effect, can be suppressed. This reliably suppresses the overabsorption of a given element contained in the second raw material on the first layer, preventing deterioration of step coverage.

[0102] (g) By using a gas that is bonded to hydrogen through a chemical bond other than the bond to the sole amino group of the given element as the second source material, the density of the given element in the second layer can be increased. When the second source material is adsorbed on the surface of wafer 200, if other ligands with a larger molecular weight than hydrogen bond to the given element, these ligands may act as steric barriers, sometimes preventing the other given elements contained in the second source material from adsorbing to the adsorption sites on the surface of wafer 200. This may result in a decrease in the density of the second layer. In contrast, by using only hydrogen as the ligand for the given element, the given element contained in the second source material can be adsorbed to the adsorption sites on the surface of wafer 200, thereby increasing the density of the given element in the second layer. Furthermore, by increasing the density of the given element in the second layer, the oxide film formation rate can be increased. Furthermore, when the second source material is adsorbed on the surface of the wafer 200, it is possible to prevent elements other than H (such as C) contained in the second source material from remaining bonded to a predetermined element in the oxide film. In other words, it is possible to reduce impurities derived from ligands in the oxide film.

[0103] (h) By using a gas containing O but not H as the oxidant, that is, by not supplying the H-containing gas in step C, the halogen element constituting the halogen cap remaining on the surface of the first layer can be suppressed from reacting with H and desorbing. This can enhance the adsorption-inhibiting effect of a given element contained in the second raw material on the surface of the first layer in step B of the next cycle. Furthermore, when reducing the halogen concentration in the oxide film is prioritized over the adsorption-inhibiting effect on the first layer, using a gas containing H and O as the oxidant may be effective.

[0104] (i) By using a gas that has not been plasma-excited (i.e., a non-plasma gas) for step C, the desorption of the halogen element that constitutes the halogen capping remaining on the surface of the first layer can be suppressed. Examples of non-plasma gases include thermally excited gases. This enhances the adsorption-inhibiting effect of the predetermined element contained in the second source material on the surface of the first layer in the subsequent step B. In particular, when using a plasma-excited gas for step C, the desorption of the halogen element that constitutes the halogen capping remaining on the surface of the first layer proceeds rapidly, making it sometimes difficult to control the amount of halogen desorption. Therefore, by using a non-plasma gas for step C, the amount of halogen element that constitutes the halogen capping remaining on the surface of the first layer can be controlled, and the amount of the predetermined element contained in the second source material adsorbed onto the surface of the first layer in the subsequent step B can be controlled. Furthermore, when prioritizing reducing the halogen concentration in the oxide film over the adsorption-inhibiting effect on the first layer, using an oxidizing agent in a plasma-excited state can sometimes be effective.

[0105] (j) In step A, the first layer is formed so that the density of the first layer formed on the opening side 301 of the concave structure 300 is greater than the density of the first layer formed on the deep side 302. This increases the rate of oxide film formation on the surface of the deep side 302 relative to the rate of oxide film formation on the surface of the opening side 301, compared to a case where the first layer is not formed. In other words, by forming the first layer in this manner, the oxide film thickness distribution can be controlled such that the rate of oxide film formation on the surface of the deep side 302 is increased, while the rate of oxide film formation on the surface of the opening side 301 is decreased, compared to a case where the first layer is not formed. For example, the thickness distribution of the second layer can be controlled so that the oxide film formation rate on the deep side 302 surface is greater than the oxide film formation rate on the opening side 301 surface, or so that the oxide film formation rate on the deep side 302 surface is approximately the same as the oxide film formation rate on the opening side 301 surface. This can improve the step coverage of the oxide film formed on the inner surface of the concave structure 300.

[0106] (4) Modification The processing sequence in this embodiment can be modified as shown in the following variations. These variations can be combined arbitrarily. Unless otherwise specified, the processing procedures and processing conditions in each step of each variation can be the same as those in the above-described processing sequence.

[0107] (Variation 1) As shown in the processing sequence below, the execution period of step A and at least a portion of the execution period of step B may be repeated, and steps A, B, and C may be performed sequentially.

[0108] (1st raw material → 1st raw material + 2nd raw material → 2nd raw material → flushing → oxidant → flushing) × n

[0109] In Modification 1, in addition to the above-mentioned effects, the cycle time can be shortened and the productivity of the film forming process can be improved.

[0110] (Variation 2) As shown in the following processing sequence, a first cycle including steps A, B, and C may be performed a first number of times (n1 times, where n1 is an integer greater than or equal to 1 or 2). Furthermore, a second cycle excluding step A but including steps B and C may be performed a second number of times (n2 times, where n2 is an integer greater than or equal to 1 or 2). For example, if the aspect ratio of the concave structure 300 decreases as shown in FIG7 at the end of the n1th cycle, a cycle excluding step A may be performed in subsequent film formation processes.

[0111] (1st raw material → rinse → 2nd raw material → rinse → oxidant → rinse) × n 1 → (2nd raw material → rinse → oxidant → rinse) × n 2

[0112] The above-mentioned effects can be obtained in Modification 2. In addition, since the number of executions of step A is reduced compared to the number of executions of step B and step C, the cycle time can be shortened and the productivity of the film forming process can be improved.

[0113] (Variation 3) As shown in the following processing sequence, steps B and C can be performed multiple times in each cycle. For example, while maintaining the adsorption barrier effect of the first layer, step A (forming the first layer) can be omitted and film formation can be performed using a cycle of steps B and C.

[0114] [first raw material → rinse → (second raw material → rinse → oxidant → rinse) × n 3] × n 4 (n 3 is an integer greater than or equal to 2, n 4 is an integer greater than or equal to 1 or 2)

[0115] The above-mentioned effects can be obtained in Modification 3. Furthermore, since the number of executions of Step A is reduced compared to the number of executions of Step B and Step C, the cycle time can be shortened and the productivity of the film forming process can be improved.

[0116] (Variation 4) As shown in the following processing sequence, the rinsing after step A can also be omitted.

[0117] (1st raw material → 2nd raw material → flushing → oxidant → flushing) × n

[0118] In variant example 4, rinsing is performed between step B and step C, thereby suppressing the generation of particles caused by the reaction between the second raw material and the oxidant and avoiding the reduction of film quality. In addition to the above effects, the cycle time can be shortened and the productivity of the film forming process can be improved.

[0119] <Other aspects of the present invention> The various aspects of the present invention have been described above in detail. However, the present invention is not limited to the above aspects and various modifications can be made without departing from the scope of the present invention.

[0120] For example, in the above embodiment, the case where the predetermined element contained in the first and second raw materials is Si is used as an example for explanation. However, the present invention is not limited to this embodiment. For example, the predetermined element may also be a metal element such as titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), aluminum (Al), molybdenum (Mo), tungsten (W), or germanium (Ge). In these cases, a metal oxide film such as a titanium oxide film (TiO film), a zirconium oxide film (ZrO film), a hafnium oxide film (HfO film), a tantalum oxide film (TaO film), a niobium oxide film (NbO film), an aluminum oxide film (AlO film), a molybdenum oxide film (MoO film), a tungsten oxide film (WO film), or a germanium oxide film (GeO film) is formed. In these cases, the same effects as in the above embodiment can be achieved.

[0121] For example, in the above embodiment, a Si film is formed as a base layer on the surface of wafer 200. However, the present invention is not limited to this embodiment. For example, an oxide film such as a SiO film or a nitride film such as a SiN film may also be formed as a base layer on the surface of wafer 200. In these cases, the same effects as those of the above embodiment can be achieved.

[0122] Furthermore, as an example, the step coverage of the oxide film formed on the inner surface of the concave structure 300 can be obtained by using the thickness T TOP of the film formed on the upper portion (edge ​​portion) of the concave structure 300 and the thickness T BOT of the film formed on the bottom surface of the concave structure 300, and substituting them into the following formula (1). Formula (1): Step coverage (%) = [T BOT / T TOP] × 100 The step coverage in the present invention is not limited to this calculation method, and may include other characteristics related to the uniformity of the thickness of the film formed on the step of the three-dimensional structure such as the concave structure 300 or other indicators representing the above uniformity. Furthermore, the improvement of the step coverage is not limited to the case where the thickness of the film formed at the step difference is close to uniform. For example, when the film is formed from bottom to top in a concave structure, when it is desired to form the film so that the film thickness increases from the upper part toward the bottom of the concave structure, it sometimes includes improving the step coverage by further increasing the film thickness at the bottom of the concave structure compared to the film thickness at the upper part (for example, the step coverage calculated by formula (1) is close to the desired value within the range of more than 100%).

[0123] The recipes used in each process are preferably prepared separately according to the process content, and are pre-recorded and stored in the memory device 121c via a communication line or external memory device 123. Furthermore, when each process is started, the CPU 121a preferably selects an appropriate recipe from the plurality of recipes recorded and stored in the memory device 121c based on the process content. This allows films of various film types, composition ratios, film qualities, and film thicknesses to be formed with high reproducibility within a single substrate processing apparatus. Furthermore, the burden on the operator is reduced, allowing each process to be started quickly while preventing operational errors.

[0124] The above-described process is not limited to newly created processes; for example, it can also be prepared by modifying an existing process recipe already installed in a substrate processing apparatus. When modifying a process recipe, the modified process can be installed in the substrate processing apparatus via a communication line or a recording medium containing the process recipe. Furthermore, the existing process recipe installed in the substrate processing apparatus can be modified directly by operating the input / output device 122 of the existing substrate processing apparatus.

[0125] In the above aspects, an example of film formation using a batch-type substrate processing apparatus that processes multiple substrates at a time was described. The present invention is not limited to the above aspects and can also be suitably applied to film formation using a single-wafer-type substrate processing apparatus that processes one or more substrates at a time. Furthermore, in the above aspects, an example of film formation using a substrate processing apparatus with a hot-wall processing furnace was described. The present invention is not limited to the above aspects and can also be suitably applied to film formation using a substrate processing apparatus with a cold-wall processing furnace.

[0126] Furthermore, when using such substrate processing apparatuses, each process can be performed according to the same processing procedures and processing conditions as those in the above-mentioned aspects and modified examples, thereby obtaining the same effects as those in the above-mentioned aspects and modified examples.

[0127] The above-mentioned aspects or modifications may be used in combination as appropriate. The processing procedures and processing conditions in this case may be, for example, the same as those in the above-mentioned aspects or modifications.

[0128] 115: Crystal Boat Elevator 115s: Gate switch mechanism 121:Controller 121a:CPU 121b:RAM 121c: Memory device 121d: I / O port 121e: Internal bus 122: Input and output devices 123: External memory device 200: Wafer (substrate) 201: Processing Room 202: Treatment furnace 203: reaction tube 207: Heater 209: Manifold 217: Crystal Boat 218: Heat insulation board 219: Sealing cover 219s: Gate 220a, 220b, 220c: O-ring 231: Exhaust pipe 231a: Exhaust port 232a, 232b, 232c, 232d, 232e: Gas supply pipes 241a, 241b, 241c, 241d, 241e: Mass flow controller (MFC) 243a, 243b, 243c, 243d, 243e: valve 244:APC valve 245: Pressure sensor 246: Vacuum Pump 248: Aggregate supply system 249a, 249b: Nozzle 250a, 250b: Gas supply holes 255: Rotation axis 263: Temperature sensor 267: Rotating mechanism 300: concave part 301: Opening side 302: Deep side

Claims

1. A substrate processing method comprising forming an oxide film containing a predetermined element on a substrate by performing the following steps (a), (b), and (c) a predetermined number of times: (a) forming a first layer containing the predetermined element and a halogen element on the substrate by supplying the substrate with a first raw material containing the predetermined element and a halogen element; (b) forming a second layer containing the predetermined element on the substrate by supplying the substrate on which the first layer is formed with a second raw material containing the predetermined element and a unique amine group bonded to the predetermined element in one molecule; and (c) oxidizing the second layer on the substrate on which the second layer is formed by supplying an oxidant.

2. The substrate processing method as described in claim 1, wherein, The oxide film is formed on the inner surface of the concave structure provided on the surface of the substrate.

3. The substrate processing method as described in claim 1, wherein, (b) is performed under the condition that the predetermined element contained in the second material is adsorbed onto the substrate by supplying the second material to the substrate to which the first layer has not been formed.

4. The substrate processing method as described in claim 3, wherein, The above processing conditions include at least one of temperature conditions and pressure conditions.

5. The substrate processing method as described in claim 1, wherein, In (b), the partial pressure of the second material supplied to the substrate is greater than the partial pressure of the first material supplied to the substrate in (a).

6. The substrate processing method as described in claim 5, wherein, The pressure in the space where the substrate in (b) exists is greater than the pressure in the space where the substrate in (a) exists.

7. The substrate processing method as described in claim 1, wherein, The first raw material mentioned above is a gas containing bonds between the aforementioned predetermined elements in one molecule.

8. The substrate processing method as described in claim 7, wherein, In (a), the first raw material is supplied to the substrate under the processing conditions under which the bonds between the predetermined elements in the gas phase are broken.

9. The substrate processing method as described in claim 7, wherein, The first raw material mentioned above is a gas that does not contain hydrogen in one molecule.

10. The substrate processing method as described in claim 1, wherein, Of the chemical bonds of the aforementioned predetermined elements constituting the second raw material, the chemical bonds other than the chemical bond with the aforementioned unique amine group are hydrogen bonds.

11. The substrate processing method as described in claim 1, wherein, The oxidant mentioned above is an oxygen-containing gas that does not contain hydrogen.

12. The substrate processing method as described in claim 1, wherein, In (c), the oxidant is supplied to the substrate in a non-plasma state.

13. The substrate processing method as described in claim 1, wherein, In (b), the second layer can be formed on the substrate by detaching the amine group from the molecule of the second raw material to become a predetermined element with unconnected bonds and adsorbing it at the adsorption site on the surface of the substrate where the first layer has not been formed.

14. The substrate processing method as described in claim 2, wherein, In (a), the first layer is formed in such a way that the density of the first layer formed on the upper end of the opening side of the concave structure is greater than the density of the first layer formed on the bottom surface of the opening.

15. The substrate processing method as described in claim 1, wherein, The supply time, partial pressure, and processing pressure of the first raw material in (a) of the mth cycle are different from the corresponding conditions in (a) of the (m+1)th cycle.

16. The substrate processing method as described in claim 1, wherein, It further includes the step of performing a second cycle a second time, which does not contain (a) but includes (b) and (c).

17. The substrate processing method as described in claim 1, wherein, Within the aforementioned period, (b) and (c) will be performed multiple times in each of the aforementioned periods.

18. A method for manufacturing a semiconductor device, comprising forming an oxide film containing a predetermined element on a substrate by performing a predetermined number of cycles including (a), (b), and (c) more than twice: (a) forming a first layer containing the predetermined element and a halogen element on the substrate by supplying a first raw material containing the predetermined element and a halogen element to the substrate; (b) forming a second layer containing the predetermined element on the substrate by supplying a second raw material containing the predetermined element and a unique amine group bonded to the predetermined element in a molecule to the substrate on which the first layer is formed; and (c) oxidizing the second layer by supplying an oxidant to the substrate on which the second layer is formed.

19. A program for executing the following procedures by means of a computer on a substrate processing apparatus, the program comprising: (a) forming a first layer containing the predetermined element and the halogen element capped on the substrate by supplying a first raw material containing a predetermined element and a halogen element to the substrate having the first layer formed thereon, thereby forming a second layer containing the predetermined element on the substrate having the predetermined element formed thereon; (c) oxidizing the second layer by supplying an oxidant to the substrate having the second layer formed thereon; and forming an oxide film containing the predetermined element on the substrate by performing the cycle comprising (a), (b), and (c) two or more times according to a predetermined number of times.

20. A substrate processing apparatus comprising: a first raw material supply system for supplying a substrate with a first raw material comprising a predetermined element and a halogen element; a second raw material supply system for supplying the substrate with a second raw material comprising the predetermined element and a unique amine group bonded to the predetermined element in one molecule; an oxidant supply system for supplying the substrate with an oxidant; and a control unit configured to control the first raw material supply system, the second raw material supply system, and the oxidant supply system to form an oxide film comprising the predetermined element on the substrate by performing a predetermined number of cycles including (a), (b), and (c) more than twice: (a) a process of forming a first layer comprising the predetermined element capped by the halogen element on the substrate by supplying the first raw material to the substrate; (b) A process of forming a second layer containing the predetermined element on the substrate by supplying the second raw material to the substrate on which the first layer is formed; and (c) A process of oxidizing the second layer by supplying the oxidant to the substrate on which the second layer is formed.

21. The substrate processing method as described in claim 1, wherein, In (a), the first raw material is adsorbed at the adsorption site formed on the outermost surface of the substrate; in (b), the second raw material is adsorbed at the adsorption site not capped by the halogen element; and in (c), the second layer is modified to form an oxide layer at the adsorption site on the outermost surface.

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