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

Abstract

The present invention relates to a semiconductor device manufacturing method, a substrate processing method, a substrate processing apparatus, and a recording medium. The object is to improve the quality of a film formed on a substrate. The semiconductor device manufacturing method includes a step of forming a film containing a first element and oxygen on a substrate by performing a cycle a predetermined number of times, the cycle including: (a) a step of supplying a modifier to the substrate to form an adsorption layer containing the modifier physically adsorbed to a surface of the substrate; (b) a step of supplying a raw material containing the first element to the substrate to cause the raw material to react with the surface of the substrate to form a first layer containing the first element on the substrate; and (c) a step of supplying an oxidizing agent to the substrate to cause the oxidizing agent to react with the first layer to modify the first layer into a second layer containing the first element and oxygen, wherein a byproduct generated at the time of formation of the first layer is adsorbed to at least either one of the first layer and the surface of the substrate through the adsorption layer.

Description

Technical Field

[0001] This disclosure relates to methods for manufacturing semiconductor devices, methods for processing substrates, apparatus for processing substrates, and recording media. Background Technology

[0002] As a step in the manufacturing process of semiconductor devices, a process of forming a film on a substrate is sometimes performed (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-124184 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The purpose of this disclosure is to provide techniques that can improve the quality of films formed on substrates.

[0008] Methods for solving problems

[0009] According to one aspect of this disclosure, a technique is provided that involves forming a film containing a first element and oxygen on a substrate by performing the following cycles a predetermined number of times.

[0010] The loop includes:

[0011] (a) A process of supplying a modifier to a substrate and forming an adsorption layer on the substrate comprising the modifier physically adsorbed on the surface of the substrate.

[0012] (b) A process of supplying a raw material containing the first element to the substrate, reacting the raw material with the surface of the substrate, and forming a first layer containing the first element on the substrate; and

[0013] (c) A process of supplying an oxidant to the substrate, reacting the oxidant with the first layer, and modifying the first layer into a second layer containing the first element and oxygen.

[0014] The adsorption layer inhibits the adsorption of byproducts generated during the formation of the first layer onto at least one of the surfaces of the first layer and the substrate.

[0015] The effects of the invention

[0016] According to this disclosure, the quality of films formed on substrates can be improved. Attached Figure Description

[0017] [ Figure 1[This is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus that may be preferably used in one embodiment of the present disclosure, and is a diagram showing part of the processing furnace 202 in longitudinal section.]

[0018] [ Figure 2 [This is a schematic diagram of a vertical processing furnace of a substrate processing apparatus that may be preferably used in one embodiment of this disclosure, and is based on...] Figure 1 The AA-line cross-sectional view shows part of the processing furnace 202.

[0019] [ Figure 3 [This is a schematic configuration diagram of the controller 121 of a substrate processing apparatus that may be preferably used in one embodiment of the present disclosure, and a block diagram showing the control system of the controller 121.]

[0020] [ Figure 4 [A diagram illustrating the gas supply sequence in one manner as described in this disclosure.]

[0021] [ Figure 5 ] Figure 5 (a) is a diagram illustrating the order of modifier supply in one embodiment of this disclosure. Figure 5 (b) is a diagram illustrating the sequence of raw material supply in one manner as described in this disclosure. Figure 5 (c) is a diagram illustrating the oxidant supply sequence in one embodiment of this disclosure. Figure 5 (d) is a diagram illustrating the order of raw material supply in one manner as described in this disclosure. Figure 5 (e) is a diagram illustrating the sequence of raw material supply in one manner as described in this disclosure. Figure 5 (f) is a diagram illustrating the oxidant supply sequence in one embodiment of this disclosure.

[0022] [ Figure 6 [Figure 1] is used to illustrate Example 1 and Comparative Example 1.

[0023] [ Figure 7 [This diagram is intended to schematically illustrate the wafer configuration within the processing chamber during the fabrication of Example 2 and Comparative Example 2.]

[0024] [ Figure 8 ] Figure 8 (a) is a diagram representing Example 2. Figure 8 (b) is a diagram representing Comparative Example 2.

[0025] Explanation of reference numerals in the attached figures

[0026] 200 wafers (substrates) Detailed Implementation

[0027] <One way of publishing this text>

[0028] The following is mainly based on Figures 1-4 This disclosure will be described in one manner. It should be noted that the accompanying drawings used in the following description are schematic diagrams, and the dimensional relationships and ratios of the elements shown in the drawings are not necessarily consistent with reality. Furthermore, the dimensional relationships and ratios of the elements in multiple drawings are not necessarily consistent with each other.

[0029] (1) Composition of substrate processing device

[0030] like Figure 1 As shown, the processing furnace 202 has a heater 207 that functions as a temperature regulator (heating unit). The heater 207 is cylindrical and is vertically mounted by being supported on a retaining plate. The heater 207 also functions as an activation mechanism (activation unit) that uses heat to activate (excite) the gas.

[0031] A reaction tube 203 is arranged concentrically with the heater 207 inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and is formed into a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and is formed into 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 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 also vertically mounted like the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow part of the cylindrical processing container. The processing chamber 201 is configured to accommodate a wafer 200 serving as a substrate. Processing of the wafer 200 is performed within this processing chamber 201.

[0032] Nozzles 249a to 249c, serving as the first to third supply units, are respectively installed in the processing chamber 201, passing through the side wall of the manifold 209. Nozzles 249a to 249c are also referred to as the first nozzle to the third nozzle, respectively. Nozzles 249a to 249c are made of heat-resistant materials such as quartz or SiC. Gas supply pipes 232a to 232c are connected to nozzles 249a to 249c, respectively. Nozzles 249a to 249c are different nozzles, and each nozzle 249a and 249c is arranged adjacent to nozzle 249b.

[0033] On gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c, serving as flow controllers (flow control units), and valves 243a to 243c, serving as on / off valves, are sequentially installed from the upstream side of the airflow. Downstream of gas supply pipes 232a to 232c, gas supply pipes 232d to 232f are connected. On gas supply pipes 232d to 232f, MFCs 241d to 241f and valves 243d to 243f, sequentially installed from the upstream side of the airflow, are respectively. Gas supply pipes 232a to 232f are, for example, made of a metal material such as SUS.

[0034] like Figure 2 As shown, nozzles 249a to 249c are respectively positioned from the lower part of the inner wall of the reaction tube 203 upwards towards the arrangement direction of the wafer 200, forming a ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200 in plan view. That is, nozzles 249a to 249c are respectively positioned in a region horizontally surrounding the wafer arrangement area, along the side of the wafer arrangement area for arranging the wafers 200. In plan view, nozzle 249b is positioned opposite the exhaust port 231a (described later) in a straight line, across the center of the wafer 200 which is being moved into the processing chamber 201. Nozzles 249a and 249c are positioned such that they are sandwiched between two sides by a straight line L passing through the center of nozzle 249b and exhaust port 231a along the inner wall of the reaction tube 203 (outer periphery of the wafer 200). The straight line L also passes through the center of nozzle 249b and wafer 200. That is, nozzle 249c can also be positioned on the opposite side of nozzle 249a, separated by a straight line L. Nozzles 249a and 249c are symmetrically arranged about the straight line L as an axis of symmetry. Gas supply holes 250a to 250c are provided on the sides of nozzles 249a to 249c, respectively. Gas supply holes 250a to 250c are respectively opened in a manner that faces exhaust port 231a when viewed from above, and can supply gas to wafer 200. Multiple gas supply holes 250a to 250c are provided in the reaction tube 203 from bottom to top.

[0035] Modifier (modified gas) is supplied into processing chamber 201 from gas supply pipe 232a via MFC 241a, valve 243a, and nozzle 249a.

[0036] Raw material (raw material gas) is supplied into the processing chamber 201 from the gas supply pipe 232b via MFC 241b, valve 243b, and nozzle 249b. The raw material can be used as one of the film-forming agents.

[0037] An oxidant (oxidizing gas) is supplied into the processing chamber 201 from the gas supply pipe 232c via MFC 241c, valve 243c, and nozzle 249c. The oxidant can be used as one of the film-forming agents.

[0038] Inactive gases are supplied to the treatment chamber 201 from gas supply pipes 232d to 232f via MFCs 241d to 241f, valves 243d to 243f, gas supply pipes 232a to 232c, and nozzles 249a to 249c. These inactive gases function as purge gases, carrier gases, and dilution gases.

[0039] The modifier supply system (modified gas supply system) is mainly composed of gas supply pipe 232a, MFC 241a, and valve 243a. The raw material supply system (raw material gas supply system) is mainly composed of gas supply pipe 232b, MFC 241b, and valve 243b. The oxidant supply system (oxidizing gas supply system) is mainly composed of gas supply pipe 232c, MFC 241c, and valve 243c. The inactive gas supply system is mainly composed of gas supply pipes 232d-232f, MFC 241d-241f, and valves 243d-243f.

[0040] Any or all of the aforementioned supply systems can be configured as an integrated supply system 248, comprising valves 243a-243f, MFCs 241a-241f, etc. The integrated supply system 248 is configured to connect to gas supply pipes 232a-232f, and the supply of various substances (various gases) into the gas supply pipes 232a-232f is controlled by the controller 121 (described later), namely, the opening and closing of valves 243a-243f, and flow regulation using MFCs 241a-241f. The integrated supply system 248 is configured as an integrated unit, either integral or modular, allowing for the assembly and disassembly of gas supply pipes 232a-232f, and enabling maintenance, replacement, and addition of the integrated supply system 248 at the unit level.

[0041] An exhaust port 231a is provided below the side wall of the reaction tube 203 for exhausting the atmosphere inside the processing chamber 201. For example... Figure 2As shown, the exhaust port 231a, when viewed from above, is positioned opposite (facing) the nozzles 249a-249c (gas supply holes 250a-250c) across the wafer 200. The exhaust port 231a can also be positioned from the lower part of the sidewall of the reaction tube 203 along the upper part, 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 (which acts as a pressure detector, or pressure detection unit) and an APC (Auto Pressure Controller) valve 244 (which acts as a pressure regulator, or pressure regulating unit). The APC valve 244 is configured to allow for vacuum exhaust and vacuum exhaust stop within the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, by adjusting the valve opening based on the pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating, the pressure within the processing chamber 201 can be adjusted. The exhaust system mainly consists of an exhaust pipe 231, an APC valve 244, and a pressure sensor 245. Alternatively, a vacuum pump 246 could be included in the exhaust system.

[0042] Below the manifold 209, a sealing cover 219, serving as a furnace opening cover, is provided to airtightly seal the lower opening of the manifold 209. The sealing cover 219 is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220b, serving as a sealing member, is provided on the upper surface of the sealing cover 219 and abuts against the lower end of the manifold 209. Below the sealing cover 219, a rotation mechanism 267 is provided to rotate the crystal boat 217 (described later). The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured such that the wafer 200 is rotated by rotating the crystal boat 217. The sealing cover 219 is configured to move vertically via a crystal boat lift 115, which serves as a lifting mechanism and is provided outside the reaction tube 203. The crystal boat lift 115 is configured as a transport device (transport mechanism) that moves the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219.

[0043] A rotation mechanism 267 is provided below the sealing cover 219 to rotate the crystal boat 217 (described later). The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. The sealing cover 219 is configured to be raised and lowered vertically by a crystal boat lift 115, which is a lifting mechanism provided outside the reaction tube 203. The crystal boat lift 115 is configured as a transport device (transport mechanism) that moves the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219.

[0044] A gate 219s, serving as a furnace opening cover, is provided below the manifold 209. This gate 219s can airtightly seal the lower opening of the manifold 209 after the sealing cover 219 has been lowered and the crystal boat 217 has been removed from the processing chamber 201. The gate 219s is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220c, serving as a sealing component, is provided on the upper surface of the gate 219s and abuts against the lower end of the manifold 209. The opening and closing actions (lifting and rotating actions, etc.) of the gate 219s are controlled by a gate opening and closing mechanism 115s.

[0045] The crystal boat 217, serving as a substrate support, is configured to hold multiple wafers 200, for example, 25 to 200 wafers 200 arranged horizontally with their centers aligned in the vertical direction and supported in a multi-layered manner, i.e., spaced apart. The crystal boat 217 is made of a heat-resistant material such as quartz or SiC. A heat-insulating plate 218, also made of a heat-resistant material such as quartz or SiC, is supported in multiple layers at the bottom of the crystal boat 217.

[0046] A temperature sensor 263, serving as a temperature detector, is installed inside the reaction tube 203. By adjusting the energization of the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature within the processing chamber 201 is adjusted to achieve the desired temperature distribution. The temperature sensor 263 is disposed along the inner wall of the reaction tube 203.

[0047] like Figure 3 As shown, the controller 121, serving as the control unit (control component), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, storage device 121c, and I / O port 121d are configured to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, such as a touch panel, is connected to the controller 121. Furthermore, an external storage device 123 can be connected to the controller 121.

[0048] Storage device 121c is composed of, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. Storage device 121c stores in a readable manner a control program that controls the operation of the substrate processing apparatus, and a process flow that describes the substrate processing steps and conditions, as described later. The process flow is a combination of steps in the substrate processing described later, executed by the controller 121, to obtain a predetermined result, and functions as a program. Hereinafter, process flow, control program, etc., will be collectively referred to as a program. Additionally, process flow will be referred to simply as a process. In this specification, the term "program" is used in cases where only a process flow is included, cases where only a control program is included, or cases where both are included. RAM 121b is configured as a memory area (working area) that temporarily holds the program and data read by CPU 121a.

[0049] I / O port 121d is connected to the aforementioned MFC241a~241f, valves 243a~243f, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotating mechanism 267, crystal boat elevator 115, gate opening and closing mechanism 115s, etc.

[0050] CPU 121a is configured to read and execute control programs from storage device 121c, and to read processes from storage device 121c based on inputs of operation commands from input / output device 122. CPU 121a is configured to control the following actions according to the read processes: flow regulation of various substances (various gases) using MFCs 241a to 241f, opening and closing of valves 243a to 243f, opening and closing of APC valve 244, pressure regulation using APC valve 244 based on pressure sensor 245, starting and stopping of vacuum pump 246, temperature regulation of heater 207 based on temperature sensor 263, rotation and rotation speed regulation of crystal boat 217 using rotating mechanism 267, lifting and lowering of crystal boat 217 using crystal boat elevator 115, and opening and closing of gate 219s using gate opening and closing mechanism 115s.

[0051] The controller 121 can be configured by installing the aforementioned program stored in the external storage device 123 onto a computer. The external storage device 123 includes, for example, a hard disk such as an HDD, an optical disk such as a CD, an optical disk such as an MO, a USB memory, or a semiconductor memory such as an SSD. The storage device 121c and the external storage device 123 constitute a computer-readable recording medium. Hereinafter, they will also be referred to collectively as a recording medium. In this specification, the term "recording medium" is used in cases where only the storage device 121c is included, cases where only the external storage device 123 is included, or cases where both are included. Providing the program to the computer can also be done without using the external storage device 123, but using communication means such as the Internet or a dedicated line.

[0052] (2) Substrate processing process

[0053] Main use Figure 4 An example of a processing sequence for forming a film on a wafer 200, which serves as a substrate, using the aforementioned substrate processing apparatus as a step in the manufacturing process of a semiconductor device will be described below. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0054] exist Figure 4 The processing sequence shown will involve a loop that includes the following steps a specified number of times (n times, where n is an integer greater than or equal to 1):

[0055] Step A: Supplying a modifier to the wafer 200 and forming an adsorption layer on the wafer 200 containing the modifier physically adsorbed on the surface of the wafer 200.

[0056] Step B involves supplying a raw material containing the first element to the wafer 200, reacting the raw material with the surface of the wafer 200, and forming a first layer containing the first element on the wafer 200; and

[0057] Step C involves supplying an oxidant to the wafer 200, causing the oxidant to react with the first layer, and modifying the first layer into a second layer containing the first element and oxygen.

[0058] It should be noted that, in Figure 4 In the processing sequence shown, byproducts generated during the formation of the first layer are adsorbed onto at least one of the first layer and the surface of the wafer 200 by means of an adsorption layer.

[0059] For convenience, the above processing sequence is sometimes shown in this specification as follows. The same wording is also used in the following descriptions of variations and other methods.

[0060] (Modifier → Raw Material → Oxidizing Agent) × n

[0061] In this specification, the term "wafer" includes both the wafer itself and a laminate of a wafer and a specified layer or film formed on its surface. The term "surface of the wafer" includes both the surface of the wafer itself and the surface of a specified layer, etc., formed on the wafer. The phrase "forming a specified layer on the wafer" includes both forming the specified layer directly on the surface of the wafer itself and forming the specified layer on top of a layer, etc., formed on the wafer. The term "substrate" has the same meaning as the term "wafer" in this specification.

[0062] In this specification, the term "agent" as used includes at least one of gaseous and liquid substances. Liquid substances include mist substances. That is, modifiers and film-forming agents (raw materials, oxidants) may each contain gaseous substances, mist substances or other liquid substances, or both.

[0063] (Wafer filling and crystal boat loading)

[0064] After multiple wafers 200 are loaded (wafer filling) into the crystal boat 217, the gate 219s is moved by the gate opening and closing mechanism 115s, opening the lower end opening of the manifold 209 (gate opening). Then, as... Figure 1 As shown, a crystal boat 217 supporting multiple wafers 200 is lifted by a crystal boat elevator 115 and moved into the processing chamber 201 (crystal boat loading). In this state, the sealing cap 219 seals the lower end of the manifold 209 by means of an O-ring 220b. It should be noted that grooves, holes, and other recessed structures are formed on the surface of the wafers 200. The aspect ratio of the recessed structure, i.e., the ratio calculated by (depth of the internal space of the recessed structure) / (width of the internal space of the recessed structure), is, for example, 10 or more.

[0065] (Pressure and temperature regulation)

[0066] After the wafer boat is loaded, vacuum pump 246 is used to perform vacuum venting (pressure reduction venting) to bring the space within processing chamber 201, where the wafer 200 is located, to the desired pressure (vacuum level). At this time, the pressure within processing chamber 201 is measured by pressure sensor 245, and APC valve 244 is controlled based on this measured pressure information. Additionally, heater 207 is used to heat the wafer 200 within processing chamber 201 to the desired processing temperature. At this time, the energization of heater 207 is controlled based on temperature information detected by temperature sensor 263 to achieve the desired temperature distribution within processing chamber 201. Furthermore, rotation of the wafer 200 is initiated using rotation mechanism 267. Venting within processing chamber 201, heating of the wafer 200, and rotation are all performed continuously, at least until the processing of the wafer 200 is completed.

[0067] (film formation)

[0068] Then, perform the following steps A through C in sequence.

[0069] [Step A]

[0070] In this step, a modifier is supplied to the wafer 200 inside the processing chamber 201.

[0071] Specifically, valve 243a is opened, allowing the modifier to flow into the gas supply pipe 232a. The modifier, with flow regulation by MFC 241a, is supplied into the processing chamber 201 via nozzle 249a and discharged from exhaust port 231a. At this time, the modifier is supplied to the wafer 200 (modifier supply). Sometimes the modifier is supplied in a state diluted with a diluent gas such as an inactive gas. Alternatively, valves 243d to 243f can be opened at this time, supplying inactive gases into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0072] By supplying a modifier to the wafer 200 under the conditions described later, the modifier is physically adsorbed onto the surface of the wafer 200, thereby forming an adsorption layer on the wafer 200 containing the modifier physically adsorbed onto the surface of the wafer 200. As a result of forming the adsorption layer, a portion of the adsorption sites present on the surface of the wafer 200 are covered by the adsorption layer, while another portion of the adsorption sites remain exposed. Here, the adsorption sites present on the surface of the wafer 200 may, for example, contain hydroxyl (OH) groups that end-cap the surface of the wafer 200. Furthermore, the modifier, as described later, contains an organic compound; therefore, at least a portion of the surface of the adsorption layer may be end-capped with hydrocarbon groups, etc.

[0073] The thickness of the adsorption layer is preferably less than one molecular layer. That is, the adsorption layer preferably contains a modifier adsorbed in a manner that discontinuously covers the surface of the wafer 200. As a result, it is possible to reliably expose a portion of the adsorption sites (OH groups) present on the surface of the wafer 200. Alternatively, in this stage, the modifier may be pre-adsorbed onto the surface of the wafer 200 in a manner that makes the thickness of the adsorption layer more than one molecular layer (i.e., the surface of the wafer 200 is pre-covered with a continuous layer), and in step A2 described later, a portion of the modifier contained in the adsorption layer is removed from the surface of the wafer 200, thereby forming an adsorption layer with a thickness of less than one molecular layer.

[0074] It should be noted that, in this step, an adsorption layer is formed on at least the surface near the opening (especially the sidewalls near the opening) of the inner surface of the concave structure formed on the surface of the wafer 200. Furthermore, as described later, in this step, it is more preferable to further form an adsorption layer on the bottom surface and sidewalls of the inner surface of the concave structure.

[0075] After the adsorption layer is formed on the wafer 200, the valve 243a is closed to stop the supply of the modifier to the processing chamber 201.

[0076] After the supply of the modifier to wafer 200 is completed (after it is stopped), as follows Figure 4 As shown, step A2, which involves venting the processing chamber 201 and removing any residual gas from it, is preferably performed while the supply of the modifier to the processing chamber 201 has been stopped. By continuously performing step A2, a portion of the modifier contained in the adsorbed layer can be removed (detached) from the surface of the wafer 200, and the density (thickness) of the adsorbed layer formed on the wafer 200 can be adjusted to the desired density (thickness). That is, in step A2, venting can be continuously performed in the processing chamber 201 until the thickness of the adsorbed layer reaches the desired density. As a result, the thickness of the first layer formed in each cycle can be optimized, and the film formation rate on the wafer 200 can be adjusted to a larger desired value. In step A2, the venting conditions in the processing chamber 201, such as venting time and venting speed, are preferably set in a manner that ensures the film formation rate on the wafer 200 reaches the desired value.

[0077] It should be noted that, as Figure 4 As shown, preferably in step A2, valves 243d to 243f are opened, and inactive gas is supplied into the processing chamber 201 through nozzles 249a to 249c. That is, in step A2, it is preferable to supply inactive gas to the wafer 200 while simultaneously venting the processing chamber 201. Furthermore, it is preferable that in step A2, as... Figure 5As shown in (a), the following steps can be performed: a step of venting the processing chamber 201 while supplying an inactive gas to the wafer 200 (inactive gas purging step); and a step of venting the processing chamber 201 after the supply of inactive gas has been stopped (vacuum purging step). Furthermore, preferably, in step A2, the purging cycle comprising (performed non-simultaneously) the steps of venting the processing chamber 201 while supplying an inactive gas to the wafer 200 and venting the processing chamber 201 after the supply of inactive gas has been stopped can be performed multiple times.

[0078] By performing step A2 in any of the above manner, a portion of the modifier physically adsorbed on the surface of wafer 200 can be more effectively removed from the surface of wafer 200, and the density (thickness) of the adsorbed layer formed on wafer 200 can be more reliably adjusted to the desired density (thickness). As a result, for example, the thickness of the first layer formed in each cycle can be further optimized, and the formation of the film on wafer 200 can be adjusted to a higher rate.

[0079] Examples of processing conditions in the supply of the modifier in step A include:

[0080] Modifier supply flow rate (excluding dilution gas): 0.01–10 g / min, more preferably 0.1–5 g / min

[0081] Diluent gas supply flow rate: 100–100,000 sccm, more preferably 1,000–50,000 sccm

[0082] Modifier supply time: 1–600 seconds, more preferably 10–300 seconds

[0083] Inactive gas supply flow rate (per gas supply tube): 0–50,000 sccm, more preferably 5,000–15,000 sccm

[0084] Processing temperature: 200–500℃, more preferably 200–350℃

[0085] Processing pressure: 100-10000 Pa, more preferably 100-1000 Pa.

[0086] It should be noted that the numerical range "100~100000sccm" in this specification refers to the range including both the lower and upper limits. Therefore, for example, "100~100000sccm" means "between 100sccm and 100000sccm". The same applies to other numerical ranges. It should also be noted that a flow rate of 0sccm indicates that the substance is not being supplied.

[0087] As a processing condition in step A2, an example can be given:

[0088] Exhaust time: 1 to 600 seconds, more preferably 10 to 300 seconds;

[0089] Inactive gas supply flow rate (per gas supply tube): 0–100,000 sccm, more preferably 0–50,000 sccm.

[0090] As a modifier, a gas containing an organic compound can be used. As a gas containing an organic compound, a gas containing at least one of the groups selected from ether compounds, ketone compounds, amine compounds, and organic hydrazine compounds can be used. As a gas containing an ether compound, a gas containing at least one of dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, tetrahydropyran, etc. can be used. As a gas containing a ketone compound, a gas containing at least one of dimethyl ketone, diethyl ketone, methyl ethyl ketone, methyl propyl ketone, etc. can be used. As a gas containing an amine compound, a gas containing at least one of methylamine compounds such as monomethylamine, dimethylamine, and trimethylamine, ethylamine compounds such as monoethylamine, diethylamine, and triethylamine, and methyl ethylamine compounds such as dimethyl ethylamine and methyl diethylamine can be used. As a gas containing an organic hydrazine compound, a gas containing at least one of methylhydrazine-based gases such as monomethyl hydrazine, dimethyl hydrazine, trimethyl hydrazine, etc. can be used. One or more of these can be used as a modifier. Furthermore, it is desirable to use a gas that is not easily chemically adsorbed onto the surface of the wafer 200 as a modifier. In order to form an adsorption layer containing a modifier that is physically adsorbed onto the surface of the wafer 200, for example, a gas that does not substantially react chemically with the adsorption sites (OH groups) on the surface of the wafer 200 can be suitably used.

[0091] As inert gases, rare gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used. More than one of these can be used as an inert gas. This also applies to the steps described later.

[0092] [Step B]

[0093] After step A is completed, raw materials are supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 with an adsorption layer formed on its surface.

[0094] Specifically, valve 243b is opened, allowing raw material to flow into gas supply pipe 232b. The raw material flow rate is regulated by MFC 241b, supplied to processing chamber 201 via nozzle 249b, and exhausted from exhaust port 231a. At this time, raw material is supplied to wafer 200 (raw material supply). Sometimes, the raw material is supplied in a diluted state with a diluent gas such as an inactive gas. Alternatively, valves 243d to 243f can be opened at this time, supplying inactive gas into processing chamber 201 via nozzles 249a to 249c, respectively.

[0095] By supplying raw materials to wafer 200 under the conditions described later, the raw materials can react with the surface of wafer 200. As described later, the raw materials comprise molecules having a first element and ligands bonded to that first element (hereinafter also referred to as raw material molecules). When the raw materials reach the surface of wafer 200, they react with the exposed surface of wafer 200 not covered by the modified layer, i.e., the adsorption sites (OH groups) exposed on the surface of wafer 200. During this reaction, the ligands detach from the first element contained in the raw materials, and the first element with unbonded bonds is chemically adsorbed (bonded) onto the surface of wafer 200 through ligand detachment. By carrying out this reaction, a first layer containing the first element is formed on wafer 200, i.e., on the exposed surface (exposed portion) of wafer 200 not covered by the adsorption layer.

[0096] It should be noted that during the formation of the first layer, certain byproducts are generated. These byproducts sometimes include ligands that have detached from the first element due to the reaction of the raw material with adsorption sites exposed on the surface of wafer 200. Additionally, for example, byproducts sometimes also include molecules from which a portion of the ligand has detached from molecules having the first element and ligands bonded to the first element. It should be noted that molecules from which a portion of the ligand has detached from molecules having the first element and ligands bonded to the first element are sometimes generated, for example, by the thermal decomposition of the raw material supplied to the processing chamber 201.

[0097] As will be discussed later, byproducts sometimes contain organic ligands (organic substances). It is undesirable for byproducts to adsorb (attach) onto the surface of the film formed on wafer 200 or for them to remain within the film. Adsorption of byproducts on the film surface and retention of byproducts within the film are major factors contributing to increased film thickness. Therefore, due to the uneven distribution of adsorbed and residual byproducts within the wafer facet and on the inner surface (inner wall) of the recessed structures on the wafer, these factors sometimes deteriorate the uniformity of film thickness within the wafer facet and the step coverage of the film formed on the inner surface of the recessed structures. Furthermore, the retention of byproducts within the film sometimes becomes a major factor contributing to decreased film quality due to increased impurities from byproducts within the film.

[0098] To address this issue, according to this method, the adsorption (attachment) of byproducts generated during the formation of the first layer to at least either the first layer or the surface of the wafer 200 can be suppressed by the adsorption layer pre-formed in step A. Thus, uncontrolled, uneven increase in film thickness on the wafer 200 caused by the adsorption of byproducts and the residue of byproducts in the film can be suppressed.

[0099] One reason why the adsorption of by-products onto the first layer and the surface of the wafer 200 can be suppressed is that the adsorption layer formed in step A reduces the amount of surface exposure of the wafer 200, i.e., the amount of adsorption sites exposed on the surface of the wafer 200 (density per unit area). As a result, by appropriately controlling the amount (degree) of reaction between the raw material and the surface of the wafer 200, the amount of ligands detached from the first element, i.e., the amount of by-products containing organic ligands, can be reduced.

[0100] Another reason for suppressing the adsorption of by-products onto the surface of the first layer and wafer 200 is that, in addition to reducing the amount of by-products generated during the formation of the first layer as described above, it is believed that the adsorption layer pre-formed in step A appropriately covers a portion of the surface of wafer 200 in a manner where by-products do not adhere (physical adsorption), or the adsorption layer functions in a manner that suppresses the adsorption (attachment) of by-products generated during the formation of the first layer onto the surface of the first layer and wafer 200. One reason why the adsorption layer functions in a manner that suppresses the adsorption of by-products onto the surface of the first layer and wafer 200 is that modifiers in a state of physical adsorption onto the surface of wafer 200, or a portion of modifiers detached from the surface of wafer 200, preferentially adsorb onto by-products compared to the surface of the first layer and wafer 200, thereby suppressing the adsorption of by-products onto the first layer. By pre-forming the adsorption layer into the bottom surface and sidewalls of the inner surface of the concave structure in step A, the adsorption of by-products onto the surface of wafer 200 and the first layer can be sufficiently suppressed even near the bottom surface of the concave structure, where modifiers sometimes have difficulty reaching.

[0101] The adsorption of byproducts that has been suppressed is removed from the treatment chamber 201 by exhaust gas. In addition, the modifier adsorbed on the byproducts is removed from the treatment chamber 201 by exhaust gas in this step and in subsequent steps.

[0102] After the first layer is formed on wafer 200, valve 243b is closed to stop the supply of raw materials to processing chamber 201.

[0103] After the supply of raw materials to wafer 200 is completed (after it stops), such as Figure 4 As shown, step B2 is preferably performed, that is, exhausting the processing chamber 201 while the supply of raw materials to the processing chamber 201 is stopped, so as to remove the gas and other gases remaining in the processing chamber 201 from the processing chamber 201.

[0104] By performing step B2, the atmosphere containing unreacted raw materials remaining in the processing chamber 201 or those that contributed to the formation of the first layer, as well as byproducts whose adsorption was inhibited by the adsorption layer, can be removed from the processing chamber 201.

[0105] Furthermore, by performing step B2, the modifier contained in the adsorption layer, i.e., the modifier physically adsorbed on the surface of the wafer 200, can be detached from the surface of the wafer 200. As a result, the presence of modifier residues in the film formed on the wafer 200 can be suppressed, making the film a film with a low concentration of impurities caused by the modifier.

[0106] Furthermore, by performing step B2, the byproducts attached to the adsorption layer, along with the modifier contained in the adsorption layer—that is, the modifier physically adsorbed onto the surface of the wafer 200—can be removed from the surface of the wafer 200. As a result, byproduct residues in the film formed on the wafer 200 can be suppressed, making the film a film with uniform in-plane thickness, excellent step coverage, and low concentration of impurities caused by byproducts.

[0107] It should be noted that, as Figure 4 As shown, in step B2, it is preferable to open valves 243d to 243f, and supply inactive gas into the processing chamber 201 through nozzles 249a to 249c. That is, in step B2, it is preferable to supply inactive gas to the wafer 200 while simultaneously venting the processing chamber 201. Furthermore, it is preferable that in step B2, as... Figure 5 As shown in (b), the following steps can be performed: venting the processing chamber 201 while supplying inactive gas to the wafer 200; and venting the processing chamber 201 after the supply of inactive gas has been stopped. Furthermore, preferably, in step B2, a purging cycle comprising (performed non-simultaneously) the following steps can be performed multiple times: venting the processing chamber 201 while supplying inactive gas to the wafer 200; and venting the processing chamber 201 after the supply of inactive gas has been stopped.

[0108] By performing step B2 in any of the above manner, a portion of the modifier physically adsorbed on the surface of the wafer 200 can be removed more effectively from the surface of the wafer 200, and the various effects described above can be obtained more reliably.

[0109] Examples of processing conditions in the raw material supply for step B include:

[0110] Raw material supply flow rate (excluding dilution gas): 0.1–10 g / min, more preferably 0.5–5 g / min

[0111] Diluent gas supply flow rate: 100–100,000 sccm, more preferably 1,000–50,000 sccm

[0112] Raw material supply time: 10–600 seconds, more preferably 30–300 seconds

[0113] Inactive gas supply flow rate (per gas supply tube): 0–50,000 sccm, more preferably 5,000–15,000 sccm.

[0114] Other conditions can be the same as those in the treatment conditions during the supply of the modifier in step A.

[0115] The processing conditions in step B2 can be the same as those in step A2.

[0116] As a raw material, a gas comprising a molecule having a first element and a ligand bonded to that first element can be used. Examples of the first element include metallic elements, preferably transition metal elements, and more preferably Group 4 elements such as zirconium (Zr), hafnium (Hf), and titanium (Ti). Furthermore, examples of ligands bonded to the first element include organic ligands, preferably hydrocarbon groups comprising at least one of the groups selected from alkyl groups such as methyl, ethyl, propyl, and butyl, cyclopentadienyl, cyclohexadienyl, and cycloheptadienyl.

[0117] As a raw material containing Zr as the first element, for example, a gas containing at least one selected from the group consisting of tetra(ethylmethylamino)zirconium (Zr[N(CH3)C2H5]4), tetra(diethylamino)zirconium (Zr[N(C2H5)2]4), tetra(dimethylamino)zirconium (Zr[N(CH3)2]4), Zr(MMP)4, Zr(O-tBu)4, and tris(dimethylamino)cyclopentadienylzirconium ((C5H5)Zr[N(CH3)2]3) can be used. One or more of these can be used as a raw material.

[0118] Additionally, as a raw material containing Hf as the first element, for example, a gas comprising at least one selected from the group consisting of tetra(ethylmethylamino)hafnium (Hf[N(CH3)C2H5]4), tetra(diethylamino)hafnium (Hf[N(C2H5)2]4), tetra(dimethylamino)hafnium (Hf[N(CH3)2]4), Hf(O-tBu)4, Hf(MMP)4, and tris(dimethylamino)cyclopentadienylhafnium ((C5H5)Hf[N(CH3)2]3) can be used. One or more of these can be used as a raw material.

[0119] Additionally, as a raw material containing Ti as the first element, for example, a gas containing at least one selected from the group consisting of tetra(ethylmethylamino)titanium (Ti[N(CH3)C2H5]4), tetra(diethylamino)titanium (Ti[N(C2H5)2]4), tetra(dimethylamino)titanium (Ti[N(CH3)2]4), Ti(O-tBu)4, Ti(MMP)4, and tris(dimethylamino)cyclopentadienyltitanium ((C5H5)Ti[N(CH3)2]3) can be used. One or more of these can be used as the raw material.

[0120] [Step C]

[0121] 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 a first layer containing the first element is formed on the surface.

[0122] Specifically, valve 243c is opened, allowing oxidant to flow into gas supply pipe 232c. The oxidant flow rate is regulated by MFC 241c, supplied to processing chamber 201 via nozzle 249c, and discharged from exhaust port 231a. At this time, oxidant is supplied to wafer 200 (oxidant supply). Oxidant is sometimes supplied in a diluted state with inert gas, other oxygen-containing gas, or other diluent gases. Alternatively, valves 243d to 243f can be opened at this time, supplying inert gas to processing chamber 201 via nozzles 249a to 249c, respectively.

[0123] By supplying an oxidant to the wafer 200 under the conditions described later, the oxidant can react with the first layer, thereby modifying (oxidizing) the first layer into a second layer containing the first element and oxygen (O).

[0124] It should be noted that byproducts are sometimes generated during the formation of the second layer. These byproducts sometimes include ligands that have detached from the first layer due to the reaction of the oxidant with the first layer. These byproducts sometimes also contain organic ligands (organic substances), similar to those generated during the formation of the first layer. Re-adsorption (re-attachment) of these byproducts to the second layer, resulting in residues of these byproducts in the film formed on wafer 200, is undesirable.

[0125] To address this issue, according to this method, the adsorption of byproducts generated during the formation of the second layer to at least either the second layer or the surface of the wafer 200 can be suppressed by the adsorption layer pre-formed in step A. This can be attributed to the fact that, similar to step B, the adsorption layer pre-formed in step A appropriately covers a portion of the surface of the wafer 200, or the adsorption layer functions in a way that inhibits (prevents) the re-adsorption (re-attachment) of byproducts generated during the formation of the second layer to the second layer.

[0126] The byproducts whose re-adsorption was suppressed are removed from the processing chamber 201 by exhaust. In addition, it is also believed that some of the byproducts whose adsorption to the second layer and the surface of the wafer 200 was suppressed are adsorbed (attached) to the adsorption layer.

[0127] After the second layer is formed on wafer 200, valve 243c is closed to stop the supply of oxidant to the processing chamber 201.

[0128] After the oxidant supply to wafer 200 is completed (after it stops), as follows: Figure 4 As shown, step C2 is preferably performed, that is, exhausting the treatment chamber 201 while the supply of oxidant to the treatment chamber 201 is stopped, so as to remove the gas and other gases remaining in the treatment chamber 201 from the treatment chamber 201.

[0129] By performing step C2, the atmosphere containing unreacted oxidant remaining in the processing chamber 201 or oxidant that has contributed to the formation of the second layer, byproducts whose adsorption has been suppressed by the adsorption layer, etc., can be removed from the processing chamber 201.

[0130] Furthermore, by performing step C2, the modifier contained in the adsorption layer, i.e., the modifier physically adsorbed on the surface of the wafer 200, can be detached from the surface of the wafer 200. As a result, the presence of modifier residues in the film formed on the wafer 200 can be suppressed, making the film a film with a low concentration of impurities caused by the modifier.

[0131] Furthermore, by performing step C2, the byproducts attached to the adsorption layer, along with the modifier contained in the adsorption layer—that is, the modifier physically adsorbed onto the surface of the wafer 200—can be removed from the surface of the wafer 200. As a result, byproduct residues in the film formed on the wafer 200 can be suppressed, making the film a film with uniform in-plane thickness, excellent step coverage, and low concentration of impurities caused by byproducts.

[0132] It should be noted that, as Figure 4 As shown, in step C2, it is preferable to open valves 243d to 243f, and supply inactive gas into the processing chamber 201 through nozzles 249a to 249c. That is, in step C2, it is preferable to supply inactive gas to the wafer 200 while simultaneously venting the processing chamber 201. Furthermore, it is preferable that in step C2, as... Figure 5As shown in (c), the following steps can be performed: venting the processing chamber 201 while supplying inactive gas to the wafer 200; and venting the processing chamber 201 after the supply of inactive gas has been stopped. Preferably, in step C2, a purging cycle comprising (performed non-simultaneously) the following steps can be performed multiple times: venting the processing chamber 201 while supplying inactive gas to the wafer 200; and venting the processing chamber 201 after the supply of inactive gas has been stopped.

[0133] By performing step C2 in any of the above manner, a portion of the modifier physically adsorbed on the surface of the wafer 200 can be removed from the surface of the wafer 200 more effectively, and the various effects described above can be obtained more reliably.

[0134] Examples of processing conditions for the oxidant supply in step C include:

[0135] Oxidant supply flow rate: 100–100,000 sccm, more preferably 1,000–10,000 sccm; Oxidant supply time: 10–600 seconds, more preferably 30–300 seconds.

[0136] Inactive gas supply flow rate (per gas supply tube): 0–50,000 sccm, more preferably 5,000–15,000 sccm.

[0137] Other conditions can be the same as those in the treatment conditions during the supply of the modifier in step A.

[0138] The processing conditions in step C2 can be the same as those in step A2.

[0139] As an oxidizing agent, for example, gases containing oxygen (O) and hydrogen (H) can be used. Gases containing O and H, for example, can be water vapor (H2O gas), hydrogen peroxide (H2O2) gas, hydrogen (H2) gas + oxygen (O2) gas, H2 gas + ozone (O3) gas, etc. One or more of these can be used as the gas containing O and H.

[0140] It should be noted that in this specification, the parallel description of "H2 gas + O2 gas" refers to a mixture of H2 gas and O2 gas. When supplying a mixed gas, the two gases can be mixed (premixed) in the supply pipe before being supplied to the processing chamber 201, or the two gases can be supplied separately to the processing chamber 201 from different supply pipes and mixed (postmixed) in the processing chamber 201.

[0141] [Number of times stipulated for implementation]

[0142] By performing steps A to C described above asynchronously a predetermined number of times (n times, where n is an integer greater than or equal to 1), a film containing the first element and O (an oxide film containing the first element) can be formed on the surface of the wafer 200, including the inner surface of the concave structure formed on the surface of the wafer 200. Preferably, the above-described cycle is repeated multiple times. That is, it is preferable that the thickness of the second layer formed in each cycle is thinner than the desired thickness, and the above-described cycle is repeated multiple times until the thickness of the oxide film formed by stacking the second layer reaches the desired thickness.

[0143] (Post-purging and atmospheric pressure recovery)

[0144] After the film is formed on the wafer 200, inert gases are supplied as purge gases into the processing chamber 201 through nozzles 249a to 249c, and exhaust gases are discharged through exhaust port 231a. This purges the processing chamber 201, removing residual gases and reaction byproducts (post-purge). Then, 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 atmospheric pressure (atmospheric pressure restoration).

[0145] (Crystal boat unloading and chip removal)

[0146] Then, the sealing cover 219 is lowered using the crystal boat lift 115, opening the lower end of the manifold 209. The processed wafer 200, supported by the crystal boat 217, is then moved from the lower end of the manifold 209 to the outside of the reaction tube 203 (crystal boat unloading). After unloading, the gate 219s is moved, sealing the lower opening of the manifold 209 by means of an O-ring 220c (gate closing). The processed wafer 200, after being moved to the outside of the reaction tube 203, is removed from the crystal boat 217 (wafer removal).

[0147] (3) Effects of this method

[0148] According to this method, one or more of the following effects can be obtained.

[0149] (a) By suppressing the adsorption of byproducts generated during the formation of the first layer, including steps A to C, to at least either the first layer or the surface of the wafer 200 through the adsorption layer, the film quality of the film formed on the wafer 200 can be improved. For example, the in-plane thickness uniformity and step coverage of the film formed on the wafer 200 can be improved. Furthermore, for example, the film formed on the wafer 200 can be made to have a low concentration of impurities caused by byproducts generated during the formation of the first layer. As an example, the concentration of impurities contained in the film formed on the wafer 200 is lower than the concentration of impurities contained in the film formed on the wafer 200 by performing the same predetermined number of cycles including steps B and C without step A.

[0150] (b) By using an adsorption layer to suppress the adsorption of byproducts generated during the formation of the second layer, including steps A to C, to at least either the second layer or the surface of the wafer 200, the film quality formed on the wafer 200 can be further improved. For example, the in-plane thickness uniformity and step coverage of the film formed on the wafer 200 can be further improved. Additionally, for example, the film formed on the wafer 200 can be made to have a lower concentration of impurities caused by byproducts generated during the formation of the second layer.

[0151] (c) Since the modifier contained in the adsorption layer is physically adsorbed onto the surface of the wafer 200, it is easily detached from the surface of the wafer 200 during the cycle including steps A to C. As a result, the film formation rate on the wafer 200 can be adjusted to a desired value, thereby improving the productivity of the film formation process. In addition, it is possible to suppress the residue of the modifier in the film formed on the wafer 200, thereby improving the quality of the film.

[0152] For example, in step A, by performing step A2, which involves venting the processing chamber 201 after supplying the modifier to the wafer 200, a portion of the modifier contained in the adsorption layer can be removed from the surface of the wafer 200. This allows the density (thickness) of the adsorption layer formed on the wafer 200 to be adjusted to a desired density (thickness). As a result, film formation on the wafer 200 can be performed at a desired rate. Furthermore, it is possible to suppress the presence of modifier residues in the film formed on the wafer 200, resulting in a film with a low concentration of impurities caused by the modifier.

[0153] For example, in step B, by performing step B2, which involves venting the processing chamber 201 after the raw material is supplied to the wafer 200, the modifier contained in the adsorption layer can be detached from the surface of the wafer 200. This suppresses the presence of modifier residues in the film formed on the wafer 200, resulting in a film with a low concentration of impurities caused by the modifier. Furthermore, by removing byproducts attached to the adsorption layer along with the modifier contained in the adsorption layer from the surface of the wafer 200, byproduct residues in the film formed on the wafer 200 can be suppressed. As a result, the film exhibits excellent in-plane uniformity, excellent step coverage, and a low concentration of impurities caused by byproducts generated during the formation of the first layer.

[0154] Furthermore, for example, in step C, by performing step C2, which involves venting the processing chamber 201 after supplying the oxidant to the wafer 200, the modifier contained in the adsorption layer can be detached from the surface of the wafer 200. This suppresses the presence of modifier residues in the film formed on the wafer 200, resulting in a film with a low concentration of impurities caused by the modifier. Additionally, by removing byproducts attached to the adsorption layer along with the modifier contained in the adsorption layer from the surface of the wafer 200, byproduct residues in the film formed on the wafer 200 can be suppressed. As a result, the film exhibits excellent in-plane uniformity, excellent step coverage, and a low concentration of impurities caused by byproducts generated during the formation of the second layer.

[0155] (d) In step A, by forming a discontinuous adsorption layer (an adsorption layer less than 1 molecular layer thick) on the wafer 200, that is, by exposing a portion of the adsorption sites (OH groups) present on the surface of the wafer 200, the first element contained in the raw material can be bonded to the adsorption sites present on the surface of the wafer 200 in step B. As a result, a film can be formed on the wafer 200 at the desired rate.

[0156] (e) The above-mentioned effects are particularly beneficial when a concave structure is formed on the surface of the wafer 200 and a film is to be formed on the inner surface of the concave structure.

[0157] This is because, when a film is to be formed on the inner surface of a concave structure formed on the surface of wafer 200, byproducts generated within the concave structure pass through the opening of the concave structure when being discharged from the concave structure. Therefore, there is a tendency for the exposure of byproducts to be greater near the opening of the concave structure compared to the area near the bottom. Consequently, byproducts tend to adsorb near the opening of the concave structure. As a result, the film thickness tends to increase near the opening of the concave structure compared to films formed near the bottom, etc., and it tends to become a film with a high concentration of impurities caused by byproducts. This problem is particularly pronounced when the concave structure has an aspect ratio of 10 or greater.

[0158] According to this method, as described above, the adsorption layer can suppress the adsorption of byproducts generated during the formation of the first and second layers onto at least one of the first and second layers and the surface of the wafer 200. Therefore, the aforementioned problem can be solved, and the step coverage of the film formed on the inner surface of the concave structure formed on the wafer 200 can be improved. It should be noted that in step A, when the adsorption layer is formed on at least the bottom surface and sidewalls of the inner surface of the concave structure, that is, when it is formed not only at the opening but also on the entire inner surface of the concave structure, the adsorption of byproducts can be suppressed not only at the opening of the concave structure but also on the bottom surface and sidewalls. As a result, the step coverage of the film formed on the wafer 200 can be further improved, and at the same time, a film with a low concentration of impurities caused by byproducts can be formed on the entire inner surface of the concave structure.

[0159] (f) When using any of the specified substances (gaseous substances or liquid substances) selected from the above-mentioned modifier group, raw material group, oxidant group, and inactive gas group, the above-mentioned effects can also be obtained.

[0160] <Other ways of publishing this text>

[0161] The foregoing has provided a detailed description of the manner in which this disclosure is made. However, this disclosure is not limited to the manner described above and various changes may be made without departing from its spirit.

[0162] For example, it can be like Figure 5 The processing sequence shown in (d) and below is such that, in step B, the raw material supply cycle, including the following steps, is performed multiple times (m times, where m is an integer greater than or equal to 2): the step of supplying raw material to the wafer 200; and the step of venting exhaust gas from the processing chamber 201 while the raw material supply is stopped. The processing conditions in each of these steps can be set to be the same as the raw material supply and processing conditions in step B2 described above.

[0163] [Modifier → (Raw Material → Exhaust Gas) × m → Oxidizing Agent] × n

[0164] If the continuous supply time of raw materials increases, the raw materials may undergo thermal decomposition, resulting in an increase in the amount of by-products generated by thermal decomposition. To suppress this increase in the amount of by-products caused by thermal decomposition, it is preferable to shorten the continuous supply time of raw materials. In this method, by supplying raw materials in time intervals, the continuous supply time can be shortened, and the formation of the first layer can be carried out while suppressing the generation (increase) of by-products.

[0165] Furthermore, under these conditions, each time the raw material supply cycle is repeated, the modifier contained in the adsorption layer can be detached from the surface of the wafer 200, further suppressing the residue of the modifier in the film. Additionally, each time the raw material supply cycle is performed, the byproducts attached to the adsorption layer, along with the modifier contained in the adsorption layer, can be removed from the surface of the wafer 200, further suppressing byproduct residue in the film. As a result, the film formed on the wafer 200 can be a film with better in-plane thickness uniformity, better step coverage, and lower concentration of impurities caused by modifiers and byproducts.

[0166] It should be noted that, as Figure 5 As shown in (d), in the exhaust step of the raw material supply cycle in this method, it is preferable to open valves 243d to 243f and supply an inactive gas as a purge gas into the processing chamber 201 through nozzles 249a to 249c.

[0167] Additionally, for example, it can be like Figure 5 In the processing sequence shown in (e) and below, the step of supplying a modifier to the wafer 200 is further performed in the above-described raw material supply cycle.

[0168] [Modifier → (Raw Material → Exhaust Gas → Modifier → Exhaust Gas) × m → Oxidizing Agent] × n

[0169] or

[0170] [Modifier → (Raw Material → Exhaust Gas → Modifier) ​​× m → Oxidizing Agent] × n

[0171] In the case of repeated feedstock supply cycles as described above, the modifier contained in the adsorption layer detaches from the surface of the wafer 200 each time it is repeated. As a result, the modifier constituting the adsorption layer may sometimes be insufficient. In such cases, by also supplying the modifier in the feedstock supply cycle, the insufficient modifier can be compensated for. Thus, the adsorption of byproducts generated each time the feedstock supply cycle is performed can be more reliably suppressed from adsorbing onto at least either the first layer or the surface of the wafer 200, thereby further improving the film quality of the film formed on the wafer 200.

[0172] It should be noted that, as Figure 5As shown in (e), in the venting step of the raw material supply cycle in this method, it is preferable to open valves 243d to 243f and supply an inactive gas as a purge gas into the processing chamber 201 through nozzles 249a to 249c. Alternatively, in the raw material supply cycle of this method, the venting step may not be performed after the step of supplying the modifier.

[0173] Additionally, for example, it can be like Figure 5 The processing sequence shown in (f) and below is such that, in step C, the oxidant supply cycle, including the steps of supplying oxidant to the wafer 200 and venting the processing chamber 201 after the oxidant supply has been stopped, is performed multiple times (m times, where m is an integer greater than or equal to 2), namely: the step of supplying oxidant to the wafer 200; and the step of venting the processing chamber 201 after the oxidant supply has been stopped. The processing conditions in these steps can be the same as the oxidant supply and processing conditions in step C2 described above.

[0174] [Modifier → Raw Material → (Oxidizing Agent → Exhaust Gas) × m] × n

[0175] In this configuration, each time the oxidant supply cycle is repeated, the modifier contained in the adsorption layer can be detached from the surface of the wafer 200, further suppressing the residue of the modifier in the film. Furthermore, each time the oxidant supply cycle is performed, the byproducts attached to the adsorption layer, along with the modifier contained in the adsorption layer, can be removed from the surface of the wafer 200, further suppressing byproduct residue in the film. As a result, the film formed on the wafer 200 can achieve better uniformity of in-plane thickness, superior step coverage, and lower concentrations of impurities caused by modifiers and byproducts.

[0176] It should be noted that, as Figure 5 As shown in (f), in the exhaust step of the oxidant supply cycle in this method, it is preferable to open valves 243d to 243f and supply an inactive gas as a purge gas into the treatment chamber 201 through nozzles 249a to 249c.

[0177] The processes used in each process are preferably prepared individually according to the processing requirements and stored in advance in the storage device 121c via a telecommunication line and external storage device 123. Furthermore, preferably, when each process begins, the CPU 121a appropriately selects a suitable process from the multiple processes stored in the storage device 121c according to the processing requirements. This allows for the reproducible formation of films of various types, compositions, qualities, and thicknesses within a single substrate processing apparatus. Additionally, it reduces the operator's workload, avoids operational errors, and enables rapid initiation of each process.

[0178] The aforementioned process is not limited to newly created cases. For example, it can also be prepared by modifying an existing process already installed in the substrate processing apparatus. In the case of process modification, the modified process can also be installed in the substrate processing apparatus via a telecommunication line and a recording medium containing the process. Alternatively, the input / output device 122 of an existing substrate processing apparatus can be operated to directly modify an existing process already installed in the substrate processing apparatus.

[0179] In the above-described method, an example of forming a film using a batch substrate processing apparatus that processes multiple substrates at a time has been described. This disclosure is not limited to the above-described method, and can also be suitably applied, for example, to cases where a monolithic substrate processing apparatus that processes one or more substrates at a time is used to form a film. Furthermore, in the above-described method, an example of forming a film using a substrate processing apparatus equipped with a hot-wall type furnace has been described. This disclosure is not limited to the above-described method, and can also be suitably applied to cases where a substrate processing apparatus equipped with a cold-wall type furnace is used to form a film.

[0180] When using these substrate processing devices, each process can be performed using the same processing steps and conditions as described above to achieve the same effect as described above.

[0181] The above methods can be used in appropriate combinations. In this case, the processing steps and conditions can be the same as those in the methods described above.

[0182] Example

[0183] (Example 1)

[0184] As an example 1, the above-described substrate processing apparatus is used, utilizing... Figure 4 The processing sequence shown involves forming a hafnium oxide (HfO) film on a patterned wafer with a concave structure on its surface. Specified substances are selected from the group of substances described above as modifiers, raw materials, oxidants, and inactive gases. The processing conditions for each step are set to specified conditions within the range of those described above.

[0185] As a comparative example 1, the above-described substrate processing apparatus was used, utilizing the... Figure 4 The processing sequence shown does not include step A; instead, an HfO film is formed on a patterned wafer with a concave structure on its surface. The same substances used in Example 1 are selected as raw materials, oxidants, and inactive gases. The processing conditions for each step are set to the specified conditions within the range of those in Example 1.

[0186] Next, regarding Example 1 and Comparative Example 1, the thickness of the HfO film formed within the concave structure was measured. The film thickness was measured at two locations within the concave structure: the periphery of the opening (TOP) and the periphery of the bottom (BTM). Then, the circulation rate at each measurement location, i.e., the thickness of the HfO film formed in each cycle, was calculated. In addition, as an indicator of the quality of step coverage, the value (step coverage) is calculated by multiplying [circulation rate at BTM / circulation rate at TOP] by 100 (%).

[0187] The results are shown in Figure 6 . Figure 6 The left vertical axis represents the cycle rate. The right vertical axis represents step coverage (%). Figure 6 The horizontal axis represents Comparative Example 1 and Example 1, respectively. The ◆ mark in the figure represents the circulation rate at TOP, the ■ mark represents the circulation rate at BTM, and the bar chart represents step coverage (%).

[0188] like Figure 6 As shown, compared to Comparative Example 1, the circulation rate at the TOP portion of Example 1 was appropriately suppressed, resulting in improved step coverage (%). This can be attributed to the fact that, as explained above, by performing step A at a predetermined time point to form the adsorption layer, byproducts entering the HfO membrane can be suppressed.

[0189] (Example 2)

[0190] As an example 2, the substrate processing apparatus described above is used, utilizing... Figure 4 The processing sequence shown involves forming an HfO film on a patterned wafer with a concave structure on its surface. Specified substances are selected from the group of substances described above as modifiers, raw materials, oxidants, and inactive gases. The processing conditions for each step are set to specified conditions within the range of those described above.

[0191] As a comparative example 2, the above-described substrate processing apparatus was used, utilizing the... Figure 4 The processing sequence shown does not include step A; instead, an HfO film is formed on a patterned wafer with a concave structure on its surface. The same substances used in Example 1 are selected as raw materials, oxidants, and inactive gases. The processing conditions for each step are set to the specified conditions within the range of those in Example 1.

[0192] When performing either Example 2 or Comparative Example 2, such as Figure 7As shown, film deposition is performed with a monitoring wafer positioned opposite the surface (processing surface) of the patterned wafer. The monitoring wafer is a silicon wafer whose upper surface (the surface not opposite the patterned wafer) and lower surface (the surface opposite the patterned wafer) are both flat (without a concave structure), and a SiO film as a substrate is formed on both the upper and lower surfaces.

[0193] Then, for Example 2 and Comparative Example 2, the thicknesses of the HfO films (hereinafter referred to as evaluation films) formed on the upper and lower surfaces of the monitoring wafer were measured. The results are shown below. Figure 8 of (a), Figure 8 (b) Figure 8 The vertical axis of (a) shows the thickness of the evaluation film in Example 2. The horizontal axis shows the distance (mm) from the measurement point to the center of the wafer. Figure 8 The vertical axis of (b) shows the thickness of the evaluation film in Comparative Example 2. The horizontal axis shows the distance (mm) from the measurement point to the center of the wafer.

[0194] As shown in the figure above, it can be seen that the evaluation film formed on the lower surface of the monitoring wafer in Example 2 is thinner than that in Comparative Example 2. This means that the amount of byproducts generated during the film formation process in Example 2 is less than that in Comparative Example 2. Regarding the reason for the reduced amount of byproducts generated in Example 2, it is believed that, as mentioned above, (1) the adsorption layer formed in step A appropriately covers the surface of the monitoring wafer in a manner that does not adsorb byproducts, or the adsorption layer functions in a manner that inhibits the adsorption of byproducts on the first and second layers, thereby suppressing the adsorption of byproducts to the surface of the monitoring wafer and the first and second layers formed thereon; (2) the adsorption layer formed in step A reduces the amount of adsorption sites exposed on the surface of the wafer 200, thereby, in step B, the degree of reaction between the raw material and the surface of the wafer 200 is appropriately controlled, resulting in a reduction in the amount of organic ligands detached from Hf; etc.

Claims

1. A substrate processing method comprising a step of forming a film containing an element and oxygen on a substrate by performing the following cycles a predetermined number of times, said cycles comprising: (a) A process of supplying a modifier to the substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate. (b) A process of supplying a raw material containing the first element to the substrate, causing the raw material to react with the surface of the substrate, and forming a first layer containing the first element on another part of the exposed portion; and (c) A process of supplying an oxidant to the substrate, causing the oxidant to react with the first layer, and modifying the first layer into a second layer containing the first element and oxygen. Specifically, the adsorption layer suppresses the adsorption of byproducts generated during the formation of the first layer onto at least one of the surfaces of the first layer and the substrate. In (b), the raw material supply cycle is performed multiple times, the raw material supply cycle including: a step of supplying the raw material to the substrate; and a step of venting the space in which the substrate exists when the supply of the raw material has stopped.

2. The substrate processing method as described in claim 1, wherein, The raw material comprises molecules having the first element and ligands bonded to the first element. The byproducts generated during the formation of the first layer include the ligands that have detached from the first element.

3. The substrate processing method as described in claim 2, wherein, The byproducts generated during the formation of the first layer include the ligands that are detached from the first element through the reaction of the raw material with adsorption sites on the surface of the substrate.

4. The substrate processing method as described in claim 2, wherein, The byproducts generated during the formation of the first layer also include molecules from which a portion of the ligand detaches from molecules having the first element and ligands bonded to the first element.

5. The substrate processing method as described in claim 4, wherein, A portion of the ligand, after being detached from the molecule having the first element and the ligand bonded to the first element, is generated by the thermal decomposition of the raw material.

6. The substrate processing method as described in claim 1, wherein, The adsorption layer suppresses the adsorption of byproducts generated during the formation of the second layer onto at least one of the surfaces of the second layer and the substrate.

7. The substrate processing method as described in claim 1, wherein, The adsorption layer contains the modifier adsorbed in a manner that discontinuously covers the surface of the substrate.

8. The substrate processing method as described in claim 1, wherein, (a) further includes a step (a2) of venting the space in the substrate after the supply of the modifier to the substrate.

9. The substrate processing method as described in claim 8, wherein, In (a2), a portion of the modifier contained in the adsorption layer is removed from the surface of the substrate.

10. The substrate processing method as described in claim 8, wherein, In (a2), the space in which the substrate exists is continuously vented until the thickness of the adsorption layer becomes the desired thickness.

11. The substrate processing method as described in claim 8, wherein, In (a2), the venting conditions of the space in which the substrate exists are set in such a way that the formation rate of the film is the desired size.

12. The substrate processing method as described in claim 1, wherein, In the process of venting the space in which the substrate exists while the supply of the raw material is stopped, the byproducts attached to the adsorption layer and the modifier contained in the adsorption layer are removed from the surface of the substrate.

13. The substrate processing method as described in claim 1, wherein, (c) further includes a step (c2) of venting the space in the substrate after the oxidant is supplied to the substrate.

14. The substrate processing method as described in claim 13, wherein, In (c2), the byproducts attached to the adsorption layer are removed from the surface of the substrate together with the modifier contained in the adsorption layer.

15. The substrate processing method according to any one of claims 1 to 14, wherein, A concave structure is formed on the substrate, and the film is formed on the inner surface of the concave structure.

16. The substrate processing method as described in claim 15, wherein, In (a), the adsorption layer is formed on at least the bottom surface and the sidewalls of the inner surface of the concave structure.

17. The substrate processing method as claimed in claim 1, wherein, The raw material supply cycle also includes the step of supplying the modifier to the substrate.

18. The substrate processing method as claimed in claim 1, wherein, The modifier contains organic compounds.

19. The substrate processing method as described in claim 18, wherein, The modifier comprises at least one selected from the group consisting of ether compounds, ketone compounds, amine compounds, and organic hydrazine compounds.

20. The substrate processing method according to any one of claims 2 to 5, wherein, The ligands include organic ligands.

21. A substrate processing method comprising a step of forming a film containing an element and oxygen on a substrate by performing the following cycles a predetermined number of times, said cycles comprising: (a) A process of supplying a modifier to the substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate. (b) A process of supplying a raw material containing the first element to the substrate, causing the raw material to react with the surface of the substrate, and forming a first layer containing the first element on another part of the exposed portion; and (c) A process of supplying an oxidant to the substrate, causing the oxidant to react with the first layer, and modifying the first layer into a second layer containing the first element and oxygen. Specifically, the adsorption layer suppresses the adsorption of byproducts generated during the formation of the first layer onto at least one of the surfaces of the first layer and the substrate. In (c), the oxidant supply cycle is performed multiple times, and the oxidant supply cycle includes: a step of supplying the oxidant to the substrate; and a step of venting the space in which the substrate exists when the oxidant supply has stopped.

22. A substrate processing method, wherein, A film containing the first element is formed on the substrate by cycling a raw material containing the first element to the substrate a predetermined number of times, the cycle comprising: (a) The step of supplying a modifier to the substrate and forming an adsorption layer comprising the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate; and (b) A step of supplying the raw material to the substrate, causing the raw material to react with the surface of the substrate, and forming a layer containing the first element on another portion of the exposed portion. In (b), byproducts generated during the formation of the layer containing the first element are adsorbed onto at least one of the surfaces of the layer containing the first element and the substrate by means of the adsorption layer. In (b), the raw material supply cycle is performed multiple times, the raw material supply cycle including: a step of supplying the raw material to the substrate; and a step of venting the space in which the substrate exists when the supply of the raw material has stopped.

23. A substrate processing apparatus, comprising: A modifier supply system that supplies modifiers to a substrate; A raw material supply system that supplies the substrate with a raw material containing the first element; An oxidant supply system that supplies an oxidant to the substrate; and The control unit is configured to control the modifier supply system, the raw material supply system, and the oxidant supply system to perform a process in which by-products generated during the suppression of the formation of the first layer using an adsorption layer are adsorbed onto at least one of the surfaces of the first layer and the substrate, while a film containing the first element and oxygen is formed on the substrate. The loop includes: (a) A process of supplying a modifier to the substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate; (b) A process of supplying a raw material containing the first element to the substrate, causing the raw material to react with the surface of the substrate, and forming the first layer containing the first element on another portion of the exposed portion; and (c) A process of supplying an oxidant to the substrate, causing the oxidant to react with the first layer, thereby modifying the first layer into a second layer containing the first element and oxygen. In (b), the raw material supply cycle is performed multiple times, the raw material supply cycle including: a process of supplying the raw material to the substrate; And, while the supply of the raw materials is stopped, the space in which the substrate exists is vented.

24. A substrate processing apparatus, comprising: A modifier supply system that supplies modifiers to a substrate; A raw material supply system that supplies the substrate with a raw material containing the first element; The control unit is configured to control the modifier supply system and the raw material supply system to perform a process in which byproducts generated during the suppression of the formation of the layer containing the first element in (b) are adsorbed onto at least one of the surface of the layer containing the first element and the substrate, while simultaneously forming a film containing the first element on the substrate. The loop includes: (a) A process of supplying a modifier to the substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate; and (b) A process of supplying a raw material containing the first element to the substrate, reacting the raw material with the surface of the substrate, and forming a layer containing the first element on another portion of the exposed portion. In (b), the raw material supply cycle is performed multiple times, the raw material supply cycle including: a process of supplying the raw material to the substrate; And, while the supply of the raw materials is stopped, the space in which the substrate exists is vented.

25. A method for manufacturing a semiconductor device, comprising a step of forming a film containing an element and oxygen on a substrate by performing the following cycles a predetermined number of times, said cycles comprising: (a) A process of supplying a modifier to a substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate. (b) A process of supplying a raw material containing the first element to the substrate, causing the raw material to react with the surface of the substrate, and forming a first layer containing the first element on another part of the exposed portion; and (c) A process of supplying an oxidant to the substrate, causing the oxidant to react with the first layer, thereby modifying the first layer into a second layer containing the first element and oxygen. Specifically, the adsorption layer suppresses the adsorption of byproducts generated during the formation of the first layer onto at least one of the surfaces of the first layer and the substrate. In (b), the raw material supply cycle is performed multiple times, the raw material supply cycle including: a step of supplying the raw material to the substrate; and a step of venting the space in which the substrate exists when the supply of the raw material has stopped.

26. A method for manufacturing semiconductor devices, wherein, A film containing the first element is formed on the substrate by cycling a raw material containing the first element to the substrate a predetermined number of times, the cycle comprising: (a) A process of supplying a modifier to the substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate. (b) A process of supplying the raw material to the substrate, causing the raw material to react with the surface of the substrate, and forming a layer containing the first element on another portion of the exposed portion; In (b), byproducts generated during the formation of the layer containing the first element are adsorbed onto at least one of the surfaces of the layer containing the first element and the substrate by means of the adsorption layer. In (b), the raw material supply cycle is performed multiple times, the raw material supply cycle including: a step of supplying the raw material to the substrate; and a step of venting the space in which the substrate exists when the supply of the raw material has stopped.

27. A computer-readable recording medium having a program recorded thereon that enables a substrate processing apparatus to perform the following steps using a computer. The step involves performing the following cycle a predetermined number of times, thereby adsorbing byproducts generated during the suppression of the formation of the first layer onto at least one of the surfaces of the first layer and the substrate, while simultaneously forming a film containing the first element and oxygen on the substrate. The loop includes: (a) The step of supplying a modifier to a substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate; (b) The step of supplying a raw material containing the first element to the substrate, causing the raw material to react with the surface of the substrate, and forming the first layer containing the first element on another portion of the exposed portion; and (c) The step of supplying an oxidant to the substrate, causing the oxidant to react with the first layer, thereby modifying the first layer into a second layer containing the first element and oxygen. In (b), the raw material supply cycle is performed multiple times, and the raw material supply cycle includes the step of supplying the raw material to the substrate; The step of venting the space in which the substrate exists while the supply of the raw material has been stopped.

28. A computer-readable recording medium containing a program that enables a substrate processing apparatus to perform the following steps using a computer. The step involves forming a film containing the first element on the substrate by cycling the raw material containing the first element to the substrate a predetermined number of times. The loop includes: (a) The step of supplying a modifier to the substrate and forming an adsorption layer containing the physically adsorbed modifier on a portion of the exposed portion of the surface of the substrate; and (b) The step of supplying the raw material to the substrate, causing the raw material to react with the surface of the substrate, and forming a layer containing the first element on another portion of the exposed portion. In (b), byproducts generated during the formation of the layer containing the first element are adsorbed onto at least one of the surfaces of the layer containing the first element and the substrate by means of the adsorption layer. In (b), the raw material supply cycle is performed multiple times, and the raw material supply cycle includes the step of supplying the raw material to the substrate; The step of venting the space in which the substrate exists while the supply of the raw material has been stopped.

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