Substrate processing method, semiconductor device manufacturing method, substrate processing apparatus, and recording medium

Abstract

The present invention relates to a substrate processing method, a semiconductor device manufacturing method, a substrate processing apparatus, and a program. Provided is a technique capable of selectively removing a film after heat treatment. The following processes are performed: (a) a process of forming a film on a substrate by exposing the substrate to a film forming agent at a first temperature; (b) a process of heat treating the film at a second temperature higher than the first temperature; (c) a process of deteriorating the film after the heat treatment by exposing the film to a deteriorating agent; and (d) a process of removing the film after the deterioration by exposing the film to a removing agent.

Description

Technical Field

[0001] This disclosure relates to substrate processing methods, methods for manufacturing semiconductor devices, substrate processing apparatus, and procedures. Background Technology

[0002] As a step in the manufacturing process of a semiconductor device, sometimes a step is performed to form a film on the surface of a substrate and to heat-treat the film (see, for example, Patent Documents 1 and 2).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-165523

[0006] Patent Document 2: International Publication No. 2015 / 045163 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Heat treatment can improve the processability of the membrane, but sometimes it is difficult to remove the membrane after the specified processing is completed.

[0009] The purpose of this disclosure is to provide a technique for selectively removing heat-treated films.

[0010] Methods for solving problems

[0011] According to one aspect of this disclosure, the following technology is provided, which performs:

[0012] (a) A process of forming a film on the substrate by exposing the substrate to a film-forming agent at a first temperature;

[0013] (b) A process of heat-treating the membrane at a second temperature higher than the first temperature described above;

[0014] (c) A process of degrading the above-mentioned heat-treated film by exposing it to a degrading agent; and

[0015] (d) The process of removing the above-mentioned deteriorated membrane by exposing it to a removal agent.

[0016] The effects of the invention

[0017] According to this disclosure, the heat-treated film can be selectively removed. Attached Figure Description

[0018] [ Figure 1 ] Figure 1This is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferred for use in one embodiment of the present disclosure, showing the processing furnace 202 portion in a longitudinal sectional view.

[0019] [ Figure 2 ] Figure 2 A schematic diagram of a vertical processing furnace of a substrate processing apparatus preferred in one embodiment of this disclosure is shown. Figure 1 The diagram shows the AA-line sectional view of the processing furnace 202 section.

[0020] [ Figure 3 ] Figure 3 This is a schematic configuration diagram of the controller 121 of a substrate processing apparatus preferred in one embodiment of the present disclosure, which is a block diagram illustrating the control system of the controller 121.

[0021] [ Figure 4 ] Figure 4 (a)~ Figure 4 (f) is a schematic diagram used to illustrate the processing order in one manner of this disclosure. Figure 4 (a) is a schematic cross-sectional view of a wafer surface portion on which a silicon oxide film (SiO film) as a first substrate and a silicon nitride film (SiN film) as a second substrate are exposed. Figure 4 (b) shows the result of Figure 4 A schematic cross-sectional view of the surface portion of the wafer after step F is performed in state (a) such that at least a portion of the molecular structure of the modifier molecules is adsorbed onto the surface of the SiO film and forms a film-forming barrier layer. Figure 4 (c) is shown by Figure 4 A cross-sectional view of the surface portion of the wafer after step A is performed in state (b) to selectively form a film on the surface of the SiN film. Figure 4 (d) is shown by Figure 4 A cross-sectional view of the surface portion of the wafer after step B is performed on the SiN film surface after heat treatment of the film formed on the SiN film surface in state (c). Figure 4 (e) is shown by Figure 4 After the state of (d) is subjected to the prescribed treatment, step C is performed, thereby causing the film on the surface of the SiN film to deteriorate. This is a cross-sectional view of the surface portion of the wafer. Figure 4 (f) is showing from Figure 4 A cross-sectional view of the surface portion of the wafer after step D is performed to remove the film formed on the surface of the SiN film, thus exposing the surface of the SiN film in state (e).

[0022] [ Figure 5 ] Figure 5This is a block diagram illustrating an example of a substrate processing system preferred in another embodiment of this disclosure.

[0023] [ Figure 6 ] Figure 6 This is a block diagram illustrating another example of a substrate processing system preferred in another aspect of this disclosure.

[0024] [ Figure 7 ] Figure 7 This is a block diagram illustrating yet another example of a substrate processing system preferred in another aspect of this disclosure.

[0025] [ Figure 8 ] Figure 8 A graph is provided to illustrate the evaluation results in the embodiments and comparative examples.

[0026] Explanation of reference numerals in the attached figures

[0027] 200 wafers (substrates) Detailed Implementation

[0028] <One way of publishing this text>

[0029] The following is mainly based on Figures 1-3 , Figure 4 (a)~ Figure 4 (f) describes one way of presenting this disclosure. 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 are not necessarily consistent among multiple drawings.

[0030] (1) Composition of substrate processing device

[0031] 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 (excitation unit) that uses heat to activate (excite) the gas.

[0032] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and is formed into a cylindrical shape that is closed at the top and open at the bottom. 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 that is open at both the top and bottom. The upper end of the manifold 209 is configured to engage with the lower end of the reaction tube 203 and support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing component. The reaction tube 203 is installed vertically, just like the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow portion of the processing container. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate. Processing of the wafer 200 is performed within the processing chamber 201.

[0033] Inside the processing chamber 201, nozzles 249a to 249c, serving as the first to third supply units, are respectively installed through the side wall of the manifold 209. These nozzles are referred to as the first nozzle to the third nozzle, respectively. The nozzles 249a to 249c are made of heat-resistant materials such as quartz or SiC. Gas supply pipes 232a to 232c are connected to each of the nozzles 249a to 249c. Each of the nozzles 249a to 249c is a separate nozzle, and each of the nozzles 249a and 249c is disposed adjacent to the nozzle 249b.

[0034] On gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c, serving as flow controllers (flow control units), and valves 243a to 243c, serving as on / off valves, are sequentially installed from the upstream side of the airflow. Gas supply pipes 232d and 232f are connected to gas supply pipe 232a downstream of valve 243a. Gas supply pipes 232e and 232g are connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232h is connected to gas supply pipe 232c downstream of valve 243c. On gas supply pipes 232d to 232h, MFCs 241d to 241h and valves 243d to 243h are sequentially installed from the upstream side of the airflow. Gas supply pipes 232a to 232h are made of a metal material such as SUS.

[0035] like Figure 2As shown, nozzles 249a to 249c are arranged in a ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200, respectively, and are positioned upwards along the inner wall of the reaction tube 203 towards the arrangement direction of the wafer 200. That is, nozzles 249a to 249c are arranged along the wafer arrangement area, horizontally surrounding the wafer arrangement area to the side of the wafer arrangement area where the wafer 200 is arranged. In plan view, nozzle 249b is arranged so that it is aligned with the exhaust port 231a (described later) in a straight line, sandwiching the center of the wafer 200 being fed into the processing chamber 201. Nozzles 249a and 249c are arranged along the inner wall of the reaction tube 203 (the outer periphery of the wafer 200) from both sides, sandwiching a straight line L (which passes through the center of nozzle 249b and exhaust port 231a). 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, sandwiching the straight line L. Nozzles 249a and 249c are arranged linearly symmetrically about the straight line L. Gas supply holes 250a and 250c for supplying gas are respectively provided on the side of nozzles 249a and 249c. Gas supply holes 250a and 250c are respectively opened in a manner opposite (facing) the exhaust port 231a when viewed from above, and are configured to supply gas toward the wafer 200. Multiple gas supply holes 250a and 250c are provided from the bottom to the top of the reaction tube 203.

[0036] The modifier is supplied to the processing chamber 201 from the gas supply pipe 232a via MFC 241a, valve 243a, and nozzle 249a.

[0037] The raw material is supplied into the processing chamber 201 from the gas supply pipe 232b via MFC 241b, valve 243b, and nozzle 249b. The raw material is used as one of the film-forming agents.

[0038] Oxidant is supplied into processing chamber 201 from gas supply pipe 232c via MFC 241c, valve 243c, and nozzle 249c. The oxidant is used as one of the film-forming agents. Additionally, the oxidant is also used as one of the degrading agents.

[0039] The catalyst is supplied into the processing chamber 201 from the gas supply pipe 232d, via MFC 241d, valve 243d, gas supply pipe 232a, and nozzle 249a. The catalyst is also used as a film-forming agent.

[0040] The remover is supplied to the processing chamber 201 from the gas supply pipe 232e via MFC 241e, valve 243e, gas supply pipe 232b, and nozzle 249b. The remover is also used as an etchant.

[0041] Inactive gases are supplied to the treatment chamber 201 from gas supply pipes 232f to 232h via MFCs 241f to 241h, valves 243f to 243h, gas supply pipes 232a to 232c, and nozzles 249a to 249c, respectively. These inactive gases function as purge gas, carrier gas, and dilution gas.

[0042] Downstream of the gas supply pipe 232c from the connection point with the gas supply pipe 232h, a remote plasma unit (hereinafter referred to as RPU) 270 is provided, which serves as a plasma excitation unit (plasma generator, plasma excitation unit) to excite the gas into a plasma state. It should be noted that the excitation of the gas into a plasma state is also simply referred to as plasma excitation. The RPU 270 excites the gas by applying high-frequency (RF) power, thereby plasmaifying the gas within the RPU 270, i.e., exciting the gas into a plasma state. As a plasma generation method, either capacitively coupled plasma (CCP) or inductively coupled plasma (ICP) methods can be used.

[0043] RPU270 is configured to excite the modifier supplied from gas supply pipe 232c into a plasma state, and supply it into processing chamber 201 in the form of plasma-excited modifier. In addition, RPU270 can also excite the oxidant supplied from gas supply pipe 232c and the inactive gas supplied from gas supply pipe 232h into a plasma state and supply it into processing chamber 201.

[0044] The modifier supply system mainly consists of gas supply pipe 232a, MFC 241a, and valve 243a. The raw material supply system mainly consists of gas supply pipe 232b, MFC 241b, and valve 243b. The oxidant supply system mainly consists of gas supply pipe 232c, MFC 241c, and valve 243c. The oxidant supply system is also referred to as the modifier supply system. The oxidant and modifier supply systems can also be mainly composed of gas supply pipe 232c, MFC 241c, valve 243c, and RPU 270. The catalyst supply system mainly consists of gas supply pipe 232d, MFC 241d, and valve 243d. The remover supply system mainly consists of gas supply pipe 232e, MFC 241e, and valve 243e. The remover supply system is also referred to as the etchant supply system. The inactive gas supply system mainly consists of gas supply pipes 232f-232h, MFC 241f-241h, and valves 243f-243h. The raw material supply system, oxidant supply system, and catalyst supply system, or all of them, are also referred to as the film-forming agent supply system.

[0045] Any or all of the aforementioned supply systems can be configured as an integrated supply system 248, which integrates valves 243a-243h, MFCs 241a-241h, etc. The integrated supply system 248 is configured such that it is connected to each of the gas supply pipes 232a-232h, and the supply of various substances (various gases) into the gas supply pipes 232a-232h is controlled by the controller 121 (described later), i.e., the opening and closing of valves 243a-243h, and flow regulation using MFCs 241a-241h, etc. The integrated supply system 248 is configured as an integral or separate integrated unit, and is configured such that it can be disassembled and reassembled relative to the gas supply pipes 232a-232h, etc., and that the integrated supply system 248 can be maintained, replaced, or added to in an integrated unit manner.

[0046] An exhaust port 231a is provided on the lower side wall of the reaction tube 203 for exhausting the atmosphere of the processing chamber 201. For example... Figure 2 As shown, the exhaust port 231a is positioned facing the nozzles 249a-249c (gas supply holes 250a-250c) while the wafer 200 is clamped in a top view. The exhaust port 231a can also be positioned from the lower part of the side wall 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 detects the pressure in the processing chamber 201) and an APC (Auto Pressure Controller) valve 244 (which acts as a pressure regulator). The APC valve 244 is configured to open and close while the vacuum pump 246 is operating, thereby enabling vacuum exhaust and stopping of the processing chamber 201. Furthermore, it is configured to regulate the pressure within the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. It is also possible to include the vacuum pump 246 within the exhaust system.

[0047] Below the manifold 209, a sealing cover 219, serving as a furnace opening cover, is provided to airtightly seal the lower opening of the manifold 209. The sealing cover 219 is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220b, serving as a sealing member, is provided on the upper surface of the sealing cover 219 and abuts against the lower end of the manifold 209. Below the sealing cover 219, a rotation mechanism 267 is provided to rotate the crystal boat 217 (described later). The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. The sealing cover 219 is configured to move vertically upwards and downwards via a crystal boat lift 115, which is a lifting mechanism located outside the reaction tube 203. The crystal boat lift 115 is configured as a transport device (transport mechanism) that moves the wafer 200 into the processing chamber 201 and moves the wafer 200 out of the processing chamber 201 by raising and lowering the sealing cover 219.

[0048] Below the manifold 209, a gate 219s serving as a furnace opening cover is provided. 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. On the upper surface of the gate 219s, an O-ring 220c serving as a sealing component is provided, abutting against the lower end of the manifold 209. The opening and closing actions (lifting, rotating, etc.) of the gate 219s are controlled by the gate opening and closing mechanism 115s.

[0049] The crystal boat 217, serving as a substrate support, is configured to hold multiple wafers 200, for example 25 to 200, arranged horizontally with their centers aligned in the vertical direction and supported in a multi-layered manner, i.e., arranged at intervals. 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.

[0050] A temperature sensor 263, serving as a temperature detector, is installed inside the reaction tube 203. By adjusting the energization to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature of the processing chamber 201 is adjusted to the desired temperature distribution. The temperature sensor 263 is disposed along the inner wall of the reaction tube 203.

[0051] like Figure 3As shown, the controller 121, serving as the control unit (control means), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, 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.

[0052] 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 steps and conditions of the substrate processing described later. The process flow functions as a program, which is a combination of steps in the substrate processing described later, executed by the controller 121 to obtain a predetermined result. Hereinafter, process flow, control program, etc., will also be referred to as a program. Furthermore, 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 storage area (working area) for temporarily holding programs, data, etc., read by CPU 121a.

[0053] I / O port 121d is connected to the aforementioned MFC241a~241h, valves 243a~243h, 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, RPU270, etc.

[0054] CPU 121a is configured to read and execute control programs from storage device 121c, and to read processes from storage device 121c based on inputs such as operation commands from input / output device 122. CPU 121a is configured to control the following actions according to the read processes: flow regulation of various substances (various gases) using MFC 241a to 241h, opening and closing of valves 243a to 243h, opening and closing of APC valve 244 and 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, opening and closing of gate 219s using gate opening and closing mechanism 115s, and plasma excitation of gas using RPU 270, etc.

[0055] The controller 121 is configured to install the aforementioned program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a hard disk such as an HDD, an optical disk such as a CD, an optical disk such as an MO, a USB memory, and a semiconductor memory such as an SSD. The storage device 121c and the external storage device 123 are configured in the form of a recording medium that can be read by a computer. Hereinafter, they will also be referred to collectively as recording media. 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. It should be noted that the program can also be provided to the computer without using the external storage device 123, but using communication means such as the Internet or a dedicated line.

[0056] (2) Substrate processing process

[0057] Main use Figure 4 (a)~ Figure 4 (f) will be explained with reference to an example of the following processing sequence: using the substrate processing apparatus described above as a step in the manufacturing process of a semiconductor device, a method for processing the substrate, namely, a processing sequence for heat-treating a film formed on a wafer 200 that serves as a substrate, and removing the heat-treated film. In the following description, a case in which a SiO film serving as a first substrate and a SiN film serving as a second substrate are exposed on the surface of a wafer 200 will be described as a representative example. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0058] Figure 4 (a)~ Figure 4 The processing order shown in (f) includes:

[0059] Step A involves exposing the wafer 200, which serves as a substrate, to a film-forming agent at a first temperature, thereby forming a film on the wafer 200.

[0060] Step B involves heat-treating the membrane at a second temperature higher than the first temperature;

[0061] Step C involves degrading the heat-treated membrane by exposing it to a degrading agent; and

[0062] Step D involves removing the deteriorated membrane by exposing it to a removal agent.

[0063] in addition, Figure 4 (a)~ Figure 4 The processing sequence shown in (f) further includes step F, namely, supplying a modifier to the wafer 200, on which a SiO film serving as a first substrate and a SiN film serving as a second substrate are exposed, thereby forming a film formation barrier layer on the surface of the SiO film serving as the first substrate. By performing step F before performing step A, it is possible to selectively (preferably) form a film on the surface of the SiN film, which serves as the first substrate and the SiN film serving as the second substrate, in step A.

[0064] It should be noted that the processing sequence of this method is illustrated in the following example: Step A includes a predetermined number of cycles (n times, where n is an integer greater than or equal to 1) of step A1, which includes supplying raw materials to wafer 200 as film-forming agents, and step A2, which includes supplying oxidant to wafer 200 as film-forming agents (performed non-simultaneously). In each of steps A1 and A2, a catalyst is also supplied to wafer 200 as a film-forming agent.

[0065] In addition, in the processing sequence of this method, an example is shown where step E, which involves performing a prescribed process on the wafer 200, occurs after step B and before step C.

[0066] For convenience, the above processing order is sometimes shown in the following description. The same wording is also used in the following descriptions of variations, alternative methods, etc.

[0067] Modifier → (raw material + catalyst → oxidant + catalyst) × n → heat treatment → specified treatment → deteriorating agent → removal agent

[0068] In this specification, the term "wafer" is used to refer to both the wafer itself and a laminate of the wafer and a specified layer or film formed on its surface. The term "surface of the wafer" is used to refer to 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" is used in the same way as "wafer."

[0069] As used in this specification, the term "agent" includes at least one of gaseous and liquid substances. Liquid substances include mist substances. That is, modifiers, film-forming agents (raw materials, oxidants, catalysts), deteriorating agents, and removal agents may each include gaseous substances, mist substances, or other liquid substances, or both.

[0070] As used in this specification, the term "layer" includes at least one of continuous layers and discontinuous layers. For example, a layer may include a continuous layer, a discontinuous layer, or both, as long as the film-forming barrier layer can produce a film-forming barrier effect.

[0071] (Wafer filling and crystal boat loading)

[0072] If multiple wafers 200 are loaded (wafer filling) into the crystal boat 217, the gate opening and closing mechanism 115s moves the gate 219s, opening the lower end of the current collector 209 (gate opening). Then, as... Figure 1 As shown, a crystal boat 217 supporting multiple wafers 200 is lifted by a crystal boat lift 115 and moved into the processing chamber 201 (crystal boat loading). In this state, the sealing cover 219 seals the lower end of the manifold 209 by means of an O-ring 220b.

[0073] It should be noted that, as Figure 4 As shown in (a), the surface of the wafer 200, which is packed in the crystal boat 217, exposes a SiO film as a first substrate and a SiN film as a second substrate. In the wafer 200, the surface of the SiO film as the first substrate has OH capping as adsorption sites over its entire surface area, while the surface of the SiN film as the second substrate does not have OH capping over a large area. Furthermore, the SiO film as the first substrate is an oxide film formed by, for example, thermal oxidation or chemical vapor deposition (CVD), and has a high film density and a large number of strong Si-O bonds compared to the film after degradation in step C described later.

[0074] (Pressure and temperature regulation)

[0075] Vacuum pump 246 is used to perform vacuum venting (pressure reduction venting) to bring the processing chamber 201, i.e., the space where the wafer 200 is located, to the desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by pressure sensor 245, and the APC valve 244 is controlled based on the measured pressure information. Additionally, the wafer 200 inside the processing chamber 201 is heated by heater 207 to achieve the desired 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 in the processing chamber 201. Furthermore, the rotation of the wafer 200 using rotation mechanism 267 is initiated. Venting of the processing chamber 201, heating of the wafer 200, and rotation are all performed continuously, at least until the processing of the wafer 200 is completed.

[0076] (Step F)

[0077] Then, a modifier is supplied to the wafer 200, that is, the wafer 200 on which a SiO film as a first substrate and a SiN film as a second substrate are exposed on the surface.

[0078] Specifically, valve 243a is opened, allowing the modifier to flow into the gas supply pipe 232a. The modifier, with its flow rate regulated by MFC 241a, is supplied into the processing chamber 201 via nozzle 249a and exhausted from the exhaust port 231a. At this time, the modifier is supplied to the wafer 200 from the side (modifier supply). At this time, valves 243f to 243h can be opened, supplying inactive gases into the processing chamber 201 via nozzles 249a to 249c respectively.

[0079] By supplying a modifier to the wafer 200 under the processing conditions described later, at least a portion of the molecular structure constituting the modifier molecules is adsorbed onto the OH-terminals of the SiO film, which serves as the first substrate, thereby modifying the surface of the SiO film to form a film-forming barrier layer. That is, in this step, by supplying a modifier that reacts with the OH-terminals to the wafer 200, at least a portion of the molecular structure constituting the modifier molecules is adsorbed onto the surface of the SiO film with OH-terminals, thereby modifying the surface of the SiO film to form a film-forming barrier layer. Thus, as... Figure 4 As shown in (b), a film-forming barrier layer is formed on the surface of the SiO film, comprising at least a portion of the molecular structure of the molecules constituting the modifier.

[0080] The film-forming barrier layer formed in this step comprises residues from the modifier, i.e., at least a portion of the molecular structure of the molecules constituting the modifier. In step A described later, the film-forming barrier layer prevents the adsorption of the raw material (film-forming agent) onto the surface of the SiO film, thus hindering (inhibiting) the film-forming reaction on the surface of the SiO film.

[0081] As at least part of the molecular structure constituting the modifier, trialkylsilyl groups such as trimethylsilyl (-SiMe3) and triethylsilyl (-SiEt3) can be used as examples. In these cases, the Si of the trimethylsilyl or triethylsilyl group is bonded to the O at the OH end, and the surface of the SiO film is capped by alkyl groups such as methyl or ethyl. The alkyl groups (alkylsilyl groups) such as methyl (trimethylsilyl) and ethyl (triethylsilyl) that cap the outermost surface of the SiO film constitute a film-forming barrier layer, which can prevent the adsorption of the raw material (film-forming agent) to the surface of the SiO film in step A described later, and hinder (suppress) the film-forming reaction on the surface of the SiO film.

[0082] Here, the film-forming barrier layer (also called the film-forming inhibition layer) has a film-forming barrier function, and is therefore sometimes referred to as an inhibitor. It should be noted that the term "inhibitor" as used in this specification includes the case of a film-forming barrier layer, the case of a modifier, the case of residues from the modifier (e.g., at least a portion of the molecular structure constituting the molecule of the modifier), and is sometimes used as a collective term for all of them.

[0083] It should be noted that in this step, sometimes at least a portion of the molecular structure constituting the modifier is also adsorbed on a portion of the surface of the SiN film serving as the second substrate, but the amount of adsorption is small, overwhelmingly much greater than the amount adsorbed on the surface of the SiO film serving as the first substrate. This selective (preferential) adsorption is achieved because the processing conditions in this step prevent gas-phase decomposition of the modifier within the processing chamber 201. Furthermore, this is because the surface of the SiO film is capped with OH molecules over its entire surface area, whereas a large portion of the surface of the SiN film is not capped with OH molecules. In this step, since the modifier does not undergo gas-phase decomposition within the processing chamber 201, at least a portion of the molecular structure constituting the modifier is not multi-deposited on the surface of the SiN film. Instead, at least a portion of the molecular structure constituting the modifier is selectively adsorbed onto the surface of both the SiO film and the SiN film, thereby selectively capping the surface of the SiO film with at least a portion of the molecular structure constituting the modifier.

[0084] Examples of processing conditions for supplying the modifier in step F include:

[0085] Processing temperature: room temperature (25℃) to 500℃, preferably room temperature (25℃) to 250℃

[0086] Processing pressure: 5–2000 Pa, preferably 10–1000 Pa

[0087] Modifier supply flow rate: 0.001–3 slm, preferably 0.001–0.5 slm

[0088] Modifier supply time: 1 second to 120 minutes, preferably 30 seconds to 60 minutes

[0089] Inactive gas supply flow rate (per gas supply pipe): 0–20 slm.

[0090] It should be noted that the numerical ranges such as "5 to 2000 Pa" in this specification refer to the lower and upper limits included within this range. Therefore, for example, "5 to 2000 Pa" means "above 5 Pa and below 2000 Pa". The same applies to other numerical ranges. Furthermore, the term "processing temperature" in this specification refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the term "processing pressure" refers to the pressure inside the processing chamber 201. Additionally, when the supply flow rate includes 0 slm, 0 slm means that no substance (gas) is supplied. These same principles apply in the following descriptions.

[0091] After selectively forming a film-forming barrier layer on the surface of the SiO film serving as the first substrate, valve 243a is closed to stop the supply of the modifier to the processing chamber 201. Then, a vacuum is applied to the processing chamber 201 to remove any residual gaseous substances. At this time, valves 243f to 243h are opened, and inactive gas is supplied to the processing chamber 201 via nozzles 249a to 249c. The inactive gas supplied by nozzles 249a to 249c acts as a purging gas, thereby purging the processing chamber 201.

[0092] As a processing condition during purging in step F, an example can be given:

[0093] Processing pressure: 1~30Pa

[0094] Inactive gas supply flow rate (per gas supply pipe): 0.5–20 slm

[0095] Inactive gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds.

[0096] It should be noted that the purging temperature in this step is preferably the same as the temperature at which the modifier is supplied.

[0097] As a modifier, for example, compounds having a structure in which amino groups are directly bonded to silicon (Si), or compounds having a structure in which amino and alkyl groups are directly bonded to silicon (Si) can be used.

[0098] As modifiers, for example, (dimethylamino)trimethylsilane ((CH3)2NSi(CH3)3, abbreviated as DMATMS), (diethylamino)triethylsilane ((C2H5)2NSi(C2H5)3, abbreviated as DEATES), (dimethylamino)triethylsilane ((CH3)2NSi(C2H5)3, abbreviated as DMATES), (diethylamino)trimethylsilane ((C2H5)2NSi(CH3)3, abbreviated as DEATMS), (dipropylamino)trimethylsilane ((C3H7)2NSi(CH3)3, abbreviated as DPATMS), (dibutylamino)trimethylsilane (dimethyl ... Methylsilane ((C4H9)2NSi(CH3)3, abbreviated as DBATMS), (trimethylsilyl)amine ((CH3)3SiNH2, abbreviated as TMSA), (triethylsilyl)amine ((C2H5)3SiNH2, abbreviated as TESA), (dimethylamino)silane ((CH3)2NSiH3, abbreviated as DMAS), (diethylamino)silane ((C2H5)2NSiH3, abbreviated as DEAS), (dipropylamino)silane ((C3H7)2NSiH3, abbreviated as DPAS), (dibutylamino)silane ((C4H9)2NSiH3, abbreviated as DBAS), etc. One or more of these can be used as modifiers.

[0099] Alternatively, as modifiers, for example, bis(dimethylamino)dimethylsilane ([(CH3)2N]2Si(CH3)2, abbreviated as BDMADMS), bis(diethylamino)diethylsilane ([(C2H5)2N]2Si(C2H5)2, abbreviated as BDEADES), bis(dimethylamino)diethylsilane ([(CH3)2N]2Si(C2H5)2, abbreviated as BDMADES), bis(diethylamino)dimethylsilane ([(C2H5)2N]2Si)2Si (CH3)2 (abbreviated as BDEADMS), bis(dimethylamino)silane ([(CH3)2N]2SiH2, abbreviated as BDMAS), bis(diethylamino)silane ([(C2H5)2N]2SiH2, abbreviated as BDEAS), bis(dimethylaminodimethylsilyl)ethane ([(CH3)2N(CH3)2Si]2C2H6, abbreviated as BDMADMSE), bis(dipropylamino)silane ([(C3H7)2N]2SiH2, abbreviated as BDPAS) bis(dibutylamino)silane ([(C4H9)2N]2SiH2, abbreviated as BDBAS), bis(dipropylamino)dimethylsilane ([(C3H7)2N]2Si(CH3)2, abbreviated as BDPADMS), bis(dipropylamino)diethylsilane ([(C3H7)2N]2Si(C2H5)2, abbreviated as BDPADES), (dimethylsilyl)diamine ((CH3(2Si(NH2)2, abbreviated as DMSDA), (diethylsilyl)diamine ((C 2H5(2Si(NH2)2, abbreviated as DESDA), (dipropylsilyl)diamine ((C3H7(2Si(NH2)2, abbreviated as DESDA), bis(dimethylaminodimethylsilyl)methane ([(CH3)2N(CH3)2Si]2CH2, abbreviated as BDMADMSM), bis(dimethylamino)tetramethyldisilane ([(CH3)2N]2(CH3)4Si2, abbreviated as BDMATMDS), etc. One or more of these can be used as modifiers.

[0100] 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.

[0101] (Step A)

[0102] After step F, the wafer 200 is exposed to a film-forming agent at a first temperature, thereby forming a film on the surface of the SiN film serving as the second substrate on the wafer 200. That is, in this step, a film is selectively (preferably) formed on the surface of the SiN film by exposing the wafer 200 to a film-forming agent that reacts with the surface of the SiN film. Specifically, this step is performed sequentially through steps A1 and A2. It should be noted that in the following examples, the film-forming agent includes raw materials, an oxidant, and a catalyst.

[0103] In this step (steps A1 and A2), the output power of the heater 207 is adjusted so that the temperature inside the processing chamber 201, i.e., the temperature of the wafer 200 (first temperature), is lower than the temperature of the wafer 200 in step B (second temperature) described later. Furthermore, in this step (steps A1 and A2), the output power of the heater 207 is adjusted so that the temperature of the wafer 200 (first temperature) is lower than, and preferably lower than, the temperature of the wafer 200 in step F.

[0104] [Step A1]

[0105] In this step, raw materials (raw material gas) and catalyst (catalyst gas) are supplied as film-forming agents to the wafer 200 after step F, i.e., after a film-forming barrier layer has been selectively formed on the surface of the SiO film serving as the first substrate. This allows the wafer 200 to be exposed to the raw materials (raw material gas) and catalyst (catalyst gas).

[0106] Specifically, valves 243b and 243d are opened, allowing raw materials and catalyst to flow into gas supply pipes 232b and 232d, respectively. The flow rates of the raw materials and catalyst are regulated by MFCs 241b and 241d, and supplied to the processing chamber 201 via nozzles 249b and 249a. They are mixed within the processing chamber 201 and exhausted from the exhaust port 231a. At this time, raw materials and catalyst (raw materials + catalyst supply) are supplied to the wafer 200 from the side. Then, valves 243f to 243h can be opened, supplying inactive gases into the processing chamber 201 via nozzles 249a to 249c.

[0107] By supplying raw materials and a catalyst to the wafer 200 under the processing conditions described later, it is possible to selectively chemically adsorb at least a portion of the molecular structure constituting the raw material molecules onto the surface of the SiO film serving as the first substrate, while simultaneously suppressing the chemical adsorption of at least a portion of the molecular structure constituting the raw material molecules onto the surface of the SiN film serving as the second substrate. Thus, a first layer is selectively formed on the surface of the SiN film. The first layer contains at least a portion of the molecular structure constituting the raw material molecules as residues from the raw material. That is, the first layer contains at least a portion of the atoms constituting the raw material.

[0108] In this step, by supplying the catalyst together with the raw materials, the above-described reaction can be carried out in a non-plasma atmosphere and at a low temperature as described later. Thus, by forming the first layer in a non-plasma atmosphere and at a low temperature as described later, the molecules and atoms constituting the film-forming barrier layer formed on the surface of the SiO film can be maintained instead of disappearing (detaching) from the surface of the SiO film.

[0109] Furthermore, by forming the first layer under a non-plasma atmosphere and at such low temperatures (described later), the raw material can be prevented from undergoing thermal decomposition (gas-phase decomposition), i.e., from self-decomposition, within the processing chamber 201. This prevents at least a portion of the molecular structure constituting the raw material from being deposited multiple times on the surfaces of the SiO and SiN films, allowing the raw material to be selectively adsorbed onto the surface of the SiN film.

[0110] It should be noted that in this step, sometimes at least a portion of the molecular structure constituting the raw material molecules is also adsorbed onto a portion of the SiO film surface, but the amount adsorbed is extremely small, far less than the amount adsorbed onto the SiN film surface by at least a portion of the molecular structure constituting the raw material molecules. This selective (preferential) adsorption is achieved because the processing conditions in this step are set to low temperatures, as described later, and conditions that prevent gas-phase decomposition of the raw material within the processing chamber 201. Furthermore, this is because a film-forming barrier layer is formed over the entire surface area of ​​the SiO film, while in contrast, no film-forming barrier layer is formed over a large area of ​​the SiN film surface.

[0111] Examples of processing conditions for supplying raw materials and catalysts in step A1 include:

[0112] Processing temperature (first temperature): room temperature (25℃) to 120℃, preferably room temperature to 90℃; processing pressure: 133 to 1333 Pa;

[0113] Raw material supply flow rate: 0.001~2slm;

[0114] Catalyst supply flow rate: 0.001–2 slm;

[0115] Inactive gas supply flow rate (per gas supply tube): 0–20 slm;

[0116] Gas supply time: 1 to 120 seconds.

[0117] After selectively forming the first layer on the surface of the SiN film serving as the second substrate, valves 243b and 243d are closed to stop the supply of raw materials and catalyst to the processing chamber 201. Then, using the same processing steps and conditions as in step A, residual gaseous substances in the processing chamber 201 are removed from the processing chamber 201 (purging). It should be noted that the processing temperature during purging in this step is preferably the same as the processing temperature during the supply of raw materials and catalyst.

[0118] As a raw material, for example, a gas containing Si, carbon (C), and halogens can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. The gas containing Si, C, and halogens preferably contains halogens in the form of chemical bonds between Si and halogens. The gas containing Si, C, and halogens preferably contains C in the form of Si-C bonds. As a gas containing Si, C, and halogens, for example, a silane-based gas containing Si, Cl, and alkylene groups having Si-C bonds, i.e., an alkylchlorosilane-based gas, can be used. Alkylenes include methylene, ethylene, propylene, butylene, etc. The alkylchlorosilane-based gas preferably contains Cl in the form of Si-Cl bonds and C in the form of Si-C bonds.

[0119] As gases containing Si, C, and halogens, alkylchlorosilane gases such as bis(trichlorosilyl)methane ((SiCl3)2CH2, abbreviated as BTCSM) and 1,2-bis(trichlorosilyl)ethane ((SiCl3)2C2H4, abbreviated as BTCSE) can be used. Alternatively, gases containing Si, C, and halogens such as alkylchlorosilane gases such as 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH3)2Si2Cl4, abbreviated as TCDMDS) and 1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH3)4Si2Cl2, abbreviated as DCTMDS), and gases containing cyclic structures composed of Si and C and halogens such as 1,1,3,3-tetrachloro-1,3-disilocyclobutane (C2H4Cl4Si2, abbreviated as TCDSCB) can be used. One or more of these can be used as raw materials.

[0120] As a catalyst, for example, an amine gas containing C, nitrogen (N), and hydrogen (H) can be used. Examples of amine gases that can be used include pyridine (C5H5N), aminopyridine (C5H6N2), methylpyridine (C6H7N), dimethylpyridine (C7H9N), and piperazine (C4H2N). 10 N2 gas, piperidine (C5H) 11 Cyclic amine gases such as N, triethylamine ((C2H5)3N, abbreviated as TEA), and chain amine gases such as diethylamine ((C2H5)2NH, abbreviated as DEA), etc., can also be used as catalysts, for example, ammonia (NH3) gas. More than one of these can be used as a catalyst. This also applies to step A2 described later.

[0121] [Step A2]

[0122] After step A1 is completed, an oxidant (oxidizing gas) and a catalyst (catalyst gas) are supplied to the wafer 200, i.e., the wafer 200 after the first layer has been selectively formed on the surface of the SiN film serving as the second substrate, as film-forming agents. This allows the wafer 200 to be exposed to the oxidant (oxidizing gas) and the catalyst (catalyst gas).

[0123] Specifically, valves 243c and 243d are opened, allowing oxidant and catalyst to flow into gas supply pipes 232c and 232d, respectively. The flow rates of the oxidant and catalyst are regulated by MFCs 241c and 241d, and supplied to the processing chamber 201 via nozzles 249c and 249a. The mixture is then exhausted from the exhaust port 231a. At this time, oxidant and catalyst (oxidant + catalyst supply) are supplied to the wafer 200 from the side. Then, valves 243f to 243h can be opened, supplying inactive gases to the processing chamber 201 via nozzles 249a to 249c.

[0124] By supplying an oxidant and a catalyst to the wafer 200 under the processing conditions described later, at least a portion of the first layer formed on the surface of the SiN film serving as the second substrate can be oxidized in step A1. Thus, a second layer, formed by oxidizing the first layer, is formed on the surface of the SiN film.

[0125] In this step, by supplying the catalyst together with the oxidant, the above reaction can be carried out in a non-plasma atmosphere and at a low temperature as described later. Thus, by forming the second layer in a non-plasma atmosphere and at a low temperature as described later, the molecules and atoms constituting the film-forming barrier layer formed on the surface of the SiO film as the first substrate can be maintained instead of disappearing (detaching) from the surface of the SiO film.

[0126] Examples of processing conditions for supplying oxidant and catalyst in step A2 include:

[0127] Processing temperature (first temperature): room temperature (25°C) to 120°C, preferably room temperature to 100°C;

[0128] Processing pressure: 133~1333Pa;

[0129] Oxidant supply flow rate: 0.001~2slm;

[0130] Catalyst supply flow rate: 0.001–2 slm;

[0131] Inactive gas supply flow rate (per gas supply tube): 0–20 slm;

[0132] Gas supply time: 1 to 120 seconds.

[0133] After the first layer formed on the surface of the SiN film, which serves as the second substrate, is oxidized and transformed into the second layer, valves 243c and 243d are closed to stop the supply of oxidant and catalyst to the processing chamber 201, respectively. Then, using the same processing steps and conditions as in step A, residual gaseous substances in the processing chamber 201 are removed (purged). It should be noted that the processing temperature during purging in this step is preferably the same as the processing temperature during the supply of oxidant and catalyst.

[0134] As an oxidizing agent, for example, a gas containing oxygen (O) and H can be used. As gases containing O and H, for example, water vapor (H2O gas), hydrogen peroxide (H2O2) gas, hydrogen (H2) gas + oxygen (O2) gas, H2 gas + ozone (O3) gas, etc., can be used. One or more of these can be used as an oxidizing agent.

[0135] It should be noted that in this specification, the description of "H2 gas + O2 gas" together refers to a mixture of H2 gas and O2 gas. When supplying a mixed gas, the two gases can be mixed in the supply pipe (pre-mixing) 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 in the processing chamber 201 (post-mixing).

[0136] As a catalyst, for example, the same catalysts as those exemplified in step A1 above can be used.

[0137] [Number of times stipulated for implementation]

[0138] By performing steps A1 and A2 asynchronously a predetermined number of times (n times, where n is an integer greater than or equal to 1), thus achieving... Figure 4 As shown in (c), a film can be selectively (preferably) formed on the surface of the SiN film serving as the second substrate on the wafer 200. The above-described cycle is preferably repeated multiple times. That is, it is preferable that the thickness of the second layer formed in each cycle is thinner than the desired film thickness, and the above-described cycle is repeated multiple times until the film thickness formed by stacking the second layer reaches the desired film thickness.

[0139] By repeating the above-described cycle multiple times, the film can be selectively grown on the surface of the SiN film, which serves as the second substrate. At this time, since a film-forming barrier layer is formed on the surface of the SiO film, which serves as the first substrate, film growth on the surface of the SiO film can be suppressed. That is, by repeating the above-described cycle multiple times, film growth on the surface of the SiN film can be promoted while suppressing film growth on the surface of the SiO film.

[0140] The film (selectively grown film) formed on the surface of the SiN film in this step preferably contains C. Films containing C are characterized by high etch resistance. Furthermore, the etch resistance of the film containing C can be further improved by the heat treatment in step B described later. Therefore, in step E described later, for example, the film containing C can be used as a hard mask. It should be noted that, for example, when using the above-described raw materials, oxidant, and catalyst, a film containing Si, C, and O (preferably a silicon oxide carbide film (SiOC film)) can be selectively grown on the surface of the SiN film serving as the second substrate.

[0141] It should be noted that during steps A1 and A2, the film-forming barrier layer formed on the surface of the SiO film is maintained on the surface of the SiO film as described above, thus inhibiting film growth on the surface of the SiO film. However, in cases where the formation of the film-forming barrier layer on the surface of the SiO film becomes insufficient for some reason, film formation and growth on the surface of the SiO film may occur, albeit very slightly. Even in such cases, the thickness of the film formed on the surface of the SiO film, which serves as the first substrate, is much thinner than the thickness of the film formed on the surface of the SiN film, which serves as the second substrate. In this specification, the term "selectively (preferably) forming a film on the surface of the second substrate" includes not only the case where no film is formed on the surface of the first substrate, but only on the surface of the second substrate, but also the case where an extremely thin film is formed on the surface of the first substrate, but a much thicker film is formed on the surface of the second substrate.

[0142] (Step B)

[0143] After step A, the film formed on the surface of the SiN film, which serves as the second substrate, on the wafer 200 is heat-treated at a second temperature higher than the first temperature. At this time, the film formation barrier layer formed on the surface of the SiO film, which serves as the first substrate, on the wafer 200 can also be heat-treated.

[0144] Specifically, in this step, the output power of the heater 207 is adjusted so that the temperature inside the processing chamber 201, i.e. the temperature of the wafer 200 after selectively forming a film on the surface of the SiN film (the second temperature), is higher than the temperature of the wafer 200 in step A (the first temperature).

[0145] According to this step, by heat-treating (annealing) the film formed on the surface of the SiN film on the wafer 200 at a second temperature higher than the first temperature, impurities contained in the film formed in step A can be removed, defects can be repaired, and the film can be hardened. By hardening the film, the processability, i.e., the etching resistance, of the film can be improved. That is, in this step, by heat-treating the film formed on the surface of the SiN film, the etching resistance of the film can be improved. Thus, by improving the etching resistance (processability) of the film through heat treatment, the heat-treated film is not easily removed, and therefore steps C and D, described later, become particularly effective.

[0146] Furthermore, according to this step, the film-forming barrier layer formed on the surface of the SiO film on the wafer 200 can also be heat-treated (annealed) at the second temperature. This allows at least a portion of the film-forming barrier layer formed on the surface of the SiO film to detach and / or become ineffective. It should be noted that the ineffectiveness of the film-forming barrier layer refers to changing the molecular structure and atomic arrangement of the molecules constituting the barrier layer, enabling the adsorption of the film-forming agent onto the surface of the SiO film as a substrate, and the reaction between the film-forming agent and the surface of the SiO film as a substrate.

[0147] As described above, by performing this step, thus achieving... Figure 4 As shown in (d), the film formed on the surface of the SiN film serving as the second substrate on the wafer 200 is hardened by heat treatment, and at least a portion of the film formation barrier layer formed on the surface of the SiO film serving as the first substrate is removed and / or rendered ineffective. That is, by performing this step, a heat-treated film exists on the surface of the SiN film serving as the second substrate, and at least a portion of the surface of the SiO film serving as the first substrate is exposed. It should be noted that... Figure 4 (d) shows an example in which the film-forming barrier layer formed on the surface of the SiO film, which serves as the first substrate, is removed, thereby exposing the surface of the SiO film, which serves as the first substrate.

[0148] It should be noted that the heat treatment in this step can be carried out with an inert gas supplied to the treatment chamber 201, or with a reactive substance such as an oxidant (oxidizing gas) supplied. In this case, the inert gas and the reactive substance such as the oxidant (oxidizing gas) are also referred to as auxiliary substances.

[0149] Examples of processing conditions for heat treatment in step B include:

[0150] Processing temperature: 120–1000℃, preferably 400–700℃

[0151] Processing pressure: 1~120000Pa

[0152] Processing time: 1–18000 seconds

[0153] Auxiliary material supply flow rate: 0-50 slm.

[0154] In this step, the second temperature is made higher than the first temperature in step A. Specifically, for example, it is preferable to satisfy a relationship where the first temperature is below 100°C and the second temperature is above 300°C, and more preferably, a relationship where the first temperature is between room temperature (25°C) and 100°C and the second temperature is between 300°C and 1000°C. By satisfying the above relationship between the first and second temperatures, the film formed on the wafer 200 at the low temperature in step A can be sufficiently hardened in this step, and the etch resistance of the film can be significantly improved. As a result, the film after the heat treatment in this step becomes a film that is more difficult to remove (etch), and steps C and D, described later, become particularly effective after this step.

[0155] It should be noted that when the first temperature in step A is below 100°C (preferably between room temperature and 100°C), if the second temperature in step B is less than 300°C, the film hardening becomes insufficient, and the film's etch resistance cannot be adequately improved. Conversely, when the first temperature is below 100°C, setting the second temperature to 300°C or higher allows for sufficient film hardening, thus significantly improving the film's etch resistance. Furthermore, if the second temperature in step B exceeds 1000°C, the impact on the thermal history of the wafer 200 increases, and the wafer 200 and the film on its surface are damaged. Conversely, setting the second temperature to below 1000°C ensures a good thermal history for the wafer 200, preventing damage to the wafer 200 and the film on its surface. For these reasons, when the first temperature in step A is below 100°C, it is preferable to set the second temperature in step B to between 300°C and 1000°C.

[0156] (Step E)

[0157] After step B, a prescribed process is performed on wafer 200, i.e., wafer 200 on the surface of the SiN film serving as the second substrate, where a heat-treated film exists. The prescribed process includes at least one of etching, film formation, and treatment. For example, the prescribed process targets films, layers, or substrates other than the heat-treated film formed on the surface of the SiN film on wafer 200. It should be noted that the prescribed process can also be performed on the heat-treated film formed on the surface of the SiN film on wafer 200.

[0158] (Etching)

[0159] In this step, etching is performed on the wafer 200, i.e., the wafer 200 on which a heat-treated film exists on its surface, as a predetermined process. Here, it is preferable to use the heat-treated film on the surface of the wafer 200, i.e., the heat-treated film formed on the surface of the SiN film, as a hard mask for etching. Therefore, in the state prior to etching, it is preferable that multiple films, including the heat-treated film, exist on the surface of the wafer 200, and during etching, films other than the heat-treated film can be removed. Thus, in this step, by performing etching as a predetermined process, films other than the heat-treated film present on the surface of the wafer 200 can be selectively removed. It should be noted that in this case, the heat-treated film functions as a hard mask, thereby preserving the SiN film of the wafer 200, which serves as the second substrate, without etching it.

[0160] For etching methods, there are no particular limitations as long as the film to be etched can be removed. For example, in this step, dry etching using an etchant can be performed as a prescribed process. As dry etching, the same method as the film removal in step D described later can be used. In addition, various F-containing gases, as shown in the example of the removal agent in step D described later, can be used as the etchant. The etchant can be supplied using the removal agent supply system described above.

[0161] (film formation)

[0162] In this step, film formation is performed on the wafer 200, i.e., the wafer 200 on which the heat-treated film exists on its surface, as a prescribed process. Preferably, this film formation process forms a film on the surface of the wafer 200 with a material different from the heat-treated film, and in particular, a film that is less prone to deterioration (oxidation) or does not deteriorate (oxidize) compared to the heat-treated film.

[0163] Regarding the film-forming process, there are no particular limitations as long as the desired film can be formed on the surface of the wafer 200. For example, in this step, as a prescribed process, it is possible to form a film that is less prone to deterioration (oxidation) or does not deteriorate (oxidize) in step C (described later) compared to the film after heat treatment. Here, the same method as the film formation in step A described above can be used as the film-forming process. Furthermore, various film-forming agents can be used as the film-forming agent used in the film-forming process, depending on the composition of the film to be formed. The film-forming agent can be supplied using the film-forming agent supply system described above.

[0164] (Handling)

[0165] In this step, the wafer 200, i.e., the wafer 200 with a heat-treated film on its surface, is subjected to processing as a prescribed treatment. The processing can target films, layers, or substrates other than the heat-treated film, or it can target the heat-treated film itself. Through processing, the following can be achieved: removal of impurities and repair of defects contained in the film, layer, or substrate to be processed; densification and hardening of the film, layer, or substrate to be processed.

[0166] There are no particular limitations on the treatment method; for example, it can be plasma treatment, thermal treatment, or both. As plasma treatment, for example, the same treatment as the oxygen plasma treatment (plasma oxidation treatment) performed in step C described later can be performed, as can nitrogen plasma treatment (plasma nitriding treatment), or inactive gas plasma treatment. As thermal treatment, for example, the same treatment as the heat treatment (annealing) performed in step B can be performed.

[0167] (Step C)

[0168] After step E, the heat-treated film formed on the surface of the SiN film, which serves as the second substrate, on the wafer 200 is exposed to a degrading agent, thereby degrading it.

[0169] In this step, a modifier is supplied to the wafer 200 after step E, i.e., to the wafer 200 after the prescribed treatment. This exposes the heat-treated SiN film formed on the surface of the wafer 200 to the modifier. When supplying the modifier to the heat-treated film, the modifier can be supplied without plasma excitation, or it can be supplied with plasma excitation. Alternatively, the modifier can be supplied without plasma excitation followed by plasma excitation, or it can be supplied with plasma excitation followed by plasma excitation without plasma excitation.

[0170] Specifically, valve 243c is opened, allowing the modifier to flow into gas supply pipe 232c. The modifier flow rate is regulated by MFC 241c, supplied to processing chamber 201 via nozzle 249c, and exhausted from exhaust port 231a. At this time, the modifier is supplied to wafer 200 from the side. Valves 243f to 243h can be opened, supplying inactive gases to processing chamber 201 via nozzles 249a to 249c respectively. Additionally, the modifier can be excited into a plasma state using RPU 270 for supply.

[0171] By supplying a modifier to the wafer 200 under the processing conditions described later, at least a portion of the heat-treated film formed on the surface of the SiN film can be modified. In this step, the film can be modified in a way that reduces the etch resistance of the film after the etch resistance has been improved by the heat treatment in step B. As a method of modifying the film in a way that reduces etch resistance, oxidation can be cited as an example. In the case of modifying the film by oxidation, in this step, at least a portion of the heat-treated film is oxidized by using an oxidizing agent as a modifier, thereby modifying the film in a way that reduces the etch resistance of the film. In this step, by using an oxidizing agent as a modifier, the etch resistance of the heat-treated film is reduced, and the heat-treated film can be effectively modified into a film that is easily removed by the remover in step D described later, i.e., a film with high reactivity with the remover.

[0172] It should be noted that if, prior to this step, the surface of the wafer 200 contains multiple films, including the heat-treated film, it is preferable to selectively degrade (oxidize) the heat-treated film among the multiple films in this step. Thus, when the surface of the wafer 200 contains multiple films, including the heat-treated film, prior to this step, by selectively degrading the heat-treated film, the degraded film among the multiple films can be selectively removed in step D described later. Here, some or all of the films other than the heat-treated film can be formed, for example, through film formation as a predetermined process performed in step E described above.

[0173] Furthermore, if the surface of the wafer 200 contains multiple films, including the heat-treated film, prior to this step, the films other than the heat-treated film are preferably films that are less prone to deterioration (oxidation) or do not deteriorate (oxidize) compared to the heat-treated film. Therefore, by utilizing this selectivity of deterioration (oxidation), the heat-treated film among the multiple films can be selectively deteriorated (oxidized). It should be noted that, although in this step, although at least a portion of the films other than the heat-treated film may deteriorate along with the heat-treated film, due to the selectivity of deterioration (oxidation), the deterioration of the heat-treated film occurs predominantly (preferentially), while the deterioration of the films other than the heat-treated film is minimal. As a result, even in this case, the heat-treated film can be selectively deteriorated (oxidized). Especially when the film other than the heat-treated film contains a SiO film, since the deterioration (oxidation) in this step has virtually no effect on the SiO film, in this case, the heat-treated film can be deteriorated (oxidized) with extremely high selectivity.

[0174] As mentioned above, even if there are multiple films on the surface of the wafer 200 other than the heat-treated film before this step, if the films other than the heat-treated film are films that are less prone to deterioration (oxidation) or do not deteriorate (oxidize) compared to the heat-treated film, then by utilizing the selectivity of deterioration (oxidation), the heat-treated film among the multiple films can be selectively deteriorated (oxidized).

[0175] In this step, for example, if the heat-treated film formed on the surface of the SiN film is a C-containing film such as a SiOC film, it is preferable to oxidize the heat-treated film to remove C from the film or to reduce the C concentration (C content) in the film. By removing C from the film or reducing the C concentration in the film, the etch resistance of the heat-treated film is reduced, and the heat-treated film can be effectively degraded into a film that is easily removed by the removal agent in step D described later. If the film formed in step A is a SiOC film, in this step, the heat-treated SiOC film can also be oxidized (removing C from the heat-treated SiOC film) to degrade it into a SiO film.

[0176] As described above, by performing this step, thus achieving... Figure 4 As shown in (e), the heat-treated film on the surface of the SiN film serving as the second substrate of the wafer 200 is degraded (oxidized), and the degraded film exists on its surface.

[0177] Examples of treatment conditions for supplying the degrading agent in step C include:

[0178] Processing temperature: 100–1000℃, preferably 150–800℃

[0179] Processing pressure: 1–13332 Pa, preferably 100–1333 Pa

[0180] Degrading agent supply flow rate: 0.1–10 slm, preferably 0.5–5 slm

[0181] The time for supplying the deteriorating agent is 1 to 3600 seconds, preferably 10 to 600 seconds, and more preferably 15 to 60 seconds.

[0182] RF power: 0~1500W.

[0183] Other processing conditions can be the same as those in step F.

[0184] After the heat-treated film on the surface of wafer 200 is degraded, valve 243c is closed to stop the supply of the degrading agent to the processing chamber 201. Then, using the same processing steps and conditions as in step F above, residual gaseous substances in the processing chamber 201 are removed from the processing chamber 201 (purging). It should be noted that the processing temperature during purging in this step is preferably the same as the processing temperature when the degrading agent is supplied.

[0185] As a modifier, for example, gases containing O and H, gases containing O, gases containing O and N, and gases containing O and C can be used. It should be noted that the modifier can be used not only through thermal excitation in a non-plasma atmosphere, but also through plasma excitation. That is, the modifier can be a modifier that has been excited into a plasma state.

[0186] As the gas containing O and H, for example, the same gas containing O and H as the various O and H gases exemplified as oxidants in step A2 above can be used. As the O-containing gas, for example, O2 gas, O3 gas, etc., can be used. As the O and N-containing gas, for example, nitric oxide (NO) gas, nitrous oxide (N2O) gas, nitrogen dioxide (NO2) gas, O2 gas + NH3 gas, O3 gas + NH3 gas, etc., can be used. As the O and C-containing gas, for example, carbon dioxide (CO2) gas, carbon monoxide (CO) gas, etc., can be used. As the deteriorating agent, one or more of the above can be used.

[0187] (Step D)

[0188] After step C, the degraded film on the surface of the SiN film formed on the wafer 200 as the second substrate is removed by exposing it to a removal agent. An example of removing the degraded film formed on the surface of the SiN film by dry etching will be described here.

[0189] In this step, a removal agent is supplied to the wafer 200 after step C, i.e., to the wafer 200 with the deteriorated film on its surface. This exposes the deteriorated film on the surface of the SiN film formed on the wafer 200 to the removal agent.

[0190] Specifically, valve 243e is opened, allowing the remover to flow into gas supply pipe 232e. The remover flow rate is regulated by MFC 241e, and it is supplied to processing chamber 201 via gas supply pipe 232b and nozzle 249b, and exhausted from exhaust port 231a. At this time, remover is supplied to wafer 200 from the side (remover supply). At this time, valves 243f to 243h can be opened, supplying inactive gas into processing chamber 201 via nozzles 249a to 249c respectively.

[0191] By supplying a remover to the wafer 200 under the processing conditions described later, the degraded film formed on the surface of the SiN film can be removed (etched). That is, in this step, the film that has been degraded after its etch resistance has been improved by the heat treatment in step B, and then its etch resistance has been reduced by the action of the remover in step C, can be effectively removed. The degraded film becomes a film that is easily removed by the remover, i.e., a film with high reactivity with the remover; therefore, in this step, the degraded film can be effectively and selectively removed.

[0192] It should be noted that, as mentioned above, if the heat-treated film is, for example, a SiOC film containing C, it is also possible to oxidize and degrade the heat-treated SiOC film into a SiO film. In this case, before this step, the surface of the wafer 200 sometimes contains: a SiO film as a film after the SiOC film has been degraded; and a SiO film formed by thermal oxidation or chemical vapor deposition. In this case, for the former SiO film, since it is a SiOC-based film formed at a low temperature of below 120°C, the film density is initially low. After removing C from the heat-treated SiOC film, the film density decreases further, and it becomes a film with many defects. In contrast, for the latter SiO film, formed by thermal oxidation or chemical vapor deposition, the film density is high compared to the former SiO film, and it is a film with fewer defects. Therefore, in this step, even if there are two different types of SiO films on the surface, it is possible to selectively remove the former SiO film (the SiO film formed by oxidizing the heat-treated SiOC film) without removing the latter SiO film (the SiO film formed by thermal oxidation or chemical vapor deposition).

[0193] Thus, in this step, by removing (etching) the deteriorated film on the surface of the SiN film formed on the wafer 200 as the second substrate, as... Figure 4 As shown in (f), the surface of the SiN film serving as the second substrate can be exposed. It should be noted that, for the reasons mentioned above, the deteriorated film can be selectively removed without removing the SiN film serving as the second substrate and the SiO film serving as the first substrate.

[0194] Examples of treatment conditions for supplying the removal agent in step D include:

[0195] Processing temperature: room temperature (25℃) to 400℃, preferably 50 to 200℃

[0196] Processing pressure: 1–13332 Pa, preferably 100–1333 Pa

[0197] The removal agent supply flow rate is 0.05–5 slm, preferably 0.1–2 slm.

[0198] Removal agent supply time: 0.1–60 minutes, preferably 1–30 minutes

[0199] Inactive gas supply flow rate (per gas supply pipe): 1 to 10 slm, preferably 2 to 10 slm.

[0200] After removing the deteriorated film from the surface of the wafer 200 and exposing the surface of the SiN film, valve 243e is closed to stop the supply of the removal agent to the processing chamber 201. Then, a vacuum is applied to the processing chamber 201 to remove any remaining gaseous substances. Next, the remaining gaseous substances are removed from the processing chamber 201 using the same processing steps and conditions as in step F above (purging). It should be noted that the processing temperature during purging in this step is preferably the same as the processing temperature during the supply of the removal agent.

[0201] As a removal agent, for example, an fluorine-containing gas can be used. Examples of fluorine-containing gases include chlorine trifluoride (ClF3), chlorine fluoride (ClF), nitrogen fluoride (NF3), hydrogen fluoride (HF), and fluorine (F2). One or more of these can be used as the fluorine-containing gas.

[0202] As described above, in this step, the deteriorated film is selectively removed. The film selectively removed in this step is preferably, for example, a C-containing film oxidized from a heat-treated SiOC film. On the other hand, in this step, films that are not removed but are desired to remain on the surface of the wafer 200 include, for example, Si films, SiO films, SiN films, silicon oxide carbon nitride films (SiOCN films), silicon oxide nitride films (SiON films), silicon carbon nitride films (SiCN films), silicon carbide films (SiC films), silicon boron carbon nitride films (SiBCN films), silicon boron nitride films (SiBN films), silicon boron carbide films (SiBC films), and other Si-containing films, as well as titanium nitride films (TiN films), tungsten films (W films), molybdenum films (Mo films), ruthenium films (Ru films), cobalt films (Co films), nickel films (Ni films), etc. These are preferably films formed by, for example, thermal oxidation, thermal nitriding, or chemical vapor deposition.

[0203] (Post-purging and atmospheric pressure recovery)

[0204] After step D is completed, inert gases are supplied as purge gases into the processing chamber 201 from nozzles 249a to 249c, and exhaust gases are discharged from exhaust port 231a. This purges the processing chamber 201, removing residual gases, reaction byproducts, etc. (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).

[0205] (Crystal boat unloading and chip removal)

[0206] 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 moves, sealing the lower end opening of the manifold 209 by means of an O-ring 220c (gate closing). The processed wafer 200 is then removed from the crystal boat 217 after being moved to the outside of the reaction tube 203 (wafer removal).

[0207] (3) Effects of this method

[0208] According to this method, one or more of the effects shown below can be obtained.

[0209] In step B, the film formed on wafer 200 by exposing it to a film-forming agent at a first temperature in step A is heat-treated at a second temperature higher than the first temperature, thereby hardening the film and improving its processability, i.e., its etch resistance. However, after the wafer 200 has undergone the prescribed treatment, it is sometimes difficult to remove the heat-treated film with improved etch resistance. In such cases, by performing step C, the film is degraded in a way that reduces its etch resistance, transforming it into a film that is easily removed by a removal agent, i.e., a film with high reactivity with the removal agent. As a result, in step D, the film that has been degraded after heat treatment can be selectively removed.

[0210] As described above, in step B, the etching resistance of the film is improved by heat treatment; in step C, the film is degraded in a way that reduces the etching resistance of the film after the heat treatment has improved it; and in step D, the degraded film, after the heat treatment has improved its etching resistance and then reduced its etching resistance, is removed. Thus, by degrading the film in a way that reduces the etching resistance of the heat-treated film, and then performing step D, the degraded film can be effectively and selectively removed.

[0211] It should be noted that in step C, the modifier can be supplied to the heat-treated film without plasma excitation. This allows for the reduction of the etch resistance of the heat-treated film while suppressing plasma damage to the wafer 200, thus transforming the heat-treated film into one that is easily removed by a remover. Alternatively, in step C, the modifier can also be supplied to the heat-treated film by plasma excitation. This allows for the utilization of plasma energy while simultaneously improving the effect of reducing the etch resistance of the heat-treated film and transforming it into one that is easily removed by a remover.

[0212] Furthermore, in step A, the following cycle is performed a predetermined number of times, the cycle comprising (performed non-simultaneously): step A1, supplying a raw material to the wafer 200 as a film-forming agent; and step A2, supplying an oxidant to the wafer 200 as a film-forming agent. This allows for well-controllable film formation on the wafer 200. Additionally, it is preferable that in at least one of steps A1 and A2, a catalyst is also supplied to the wafer 200. This improves the reactivity of the reaction occurring in at least one of steps A1 and A2, enabling film formation at lower temperatures.

[0213] Furthermore, when the film formed in step A is a SiOC film containing Si, C, and O, the heat treatment in step B and the deterioration in step C can be performed more appropriately. After undergoing the heat treatment in step B, the film containing Si, C, and O can be transformed into a film that is easily removed by the removal agent, i.e., a film with high reactivity with the removal agent, thereby significantly achieving the aforementioned effects.

[0214] (4) Variations

[0215] The processing order in this method can be changed as shown in the following variations. These variations can be combined arbitrarily. Unless otherwise specified, the processing steps and conditions in each step of each variation can be the same as those in each step of the above processing order.

[0216] (Variation Example 1)

[0217] Step F in the above-described method can be omitted, as shown in the following processing sequence. For example, if it is not necessary to selectively form a film on a specified surface of wafer 200 in step A, step F can be omitted. In this modified example, the same effect as described above can also be obtained. Furthermore, by omitting step F, the total processing time can be shortened, and productivity can be improved.

[0218] (Raw material + catalyst → Oxidant + catalyst) × n → Heat treatment → Specified treatment → Deteriorating agent → Removing agent

[0219] (Variation Example 2)

[0220] The processing sequence can be as follows: in step A1, a raw material is supplied to the wafer 200 as a film-forming agent without a catalyst. Similarly, in step A2, an oxidant can be supplied to the wafer 200 as a film-forming agent without a catalyst. By supplying both the raw material and the catalyst to the wafer 200, at least a portion of the molecular structure constituting the raw material can be chemically adsorbed onto the wafer surface at low temperatures. Furthermore, by supplying both the oxidant and the catalyst to the wafer 200, the oxidation rate can be increased at low temperatures. However, when the chemical adsorption reaction of at least a portion of the molecular structure constituting the raw material onto the wafer surface and the oxidation rate are adjusted by selecting the type (characteristics) of the raw material, the processing temperature, the processing pressure, and other processing conditions, the supply of the catalyst in steps A1 and A2 can be omitted. In this modified example, the same effects as described above can also be obtained.

[0221] Modifier → (raw material → oxidant + catalyst) × n → heat treatment → specified treatment → deteriorating agent → removal agent

[0222] Modifier → (raw material + catalyst → oxidant) × n → heat treatment → specified treatment → deteriorating agent → removal agent

[0223] Modifier → (raw material → oxidant) × n → heat treatment → specified treatment → deteriorating agent → removal agent

[0224] (Variation Example 3)

[0225] Step B can be performed simultaneously with step E, or it can be performed after step E, as shown in the following processing sequence. That is, step B can be performed before step E as described above, or it can be performed during or after step E, as in this variation. When steps B and E are performed simultaneously, the wafer 200 is heat-treated at a second temperature higher than the first temperature, and a predetermined process (etching, film formation, treatment) is performed simultaneously. By performing steps B and E simultaneously, the time for performing steps B and E can be shortened. In this variation, the same effect as described above can also be obtained.

[0226] Modifier → (raw material + catalyst → oxidant + catalyst) × n → heat treatment + specified treatment → deteriorating agent → removal agent

[0227] Modifier → (raw material + catalyst → oxidant + catalyst) × n → prescribed treatment → heat treatment → deteriorating agent → removal agent

[0228] <Another way of publishing this text>

[0229] 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 may be modified in various ways without departing from its spirit.

[0230] For example, at least one of steps F, A, B, E, C, and D can be performed in a different processing unit, i.e., another processing chamber (ex-situ). In this case, steps F, A, B, E, C, and D are implemented by a substrate processing system having different processing units for performing one or more of the steps.

[0231] (Alternative Method 1)

[0232] like Figure 5 As shown, in another method 1, an example is illustrated where steps F, A, B, E, C, and D are performed in different processing chambers (ex-situ). It should be noted that another method 1 is also an example where steps F and A are performed in the same processing chamber (in-situ). Figure 5As shown, another method 1 can be implemented by a substrate processing system having five processing sections (five independent devices) including a film forming section, a heat treatment section, a specified processing section, a degradation section, and a removal section. Figure 5 In the process, steps F and A are performed in the film-forming section, step B is performed in the heat treatment section, step E is performed in the specified treatment section, step C is performed in the deterioration section, and step D is performed in the removal section.

[0233] (Alternative Method 2)

[0234] like Figure 6 As shown, in another method 2, an example is illustrated where steps F, A, B, E, C, and D are performed in different processing chambers (ex-situ). It should be noted that another method 2 also includes an example where steps F, B, and A are performed in the same processing chamber (in-situ). Figure 6 As shown, another method 2 can be implemented by a substrate processing system having four processing units (four independent devices) including a film forming unit and a heat treatment unit, a specified processing unit, a degradation unit, and a removal unit. Figure 6 In this process, steps F, A, and B are performed in the film formation and heat treatment section, step E is performed in the specified treatment section, step C is performed in the degradation section, and step D is performed in the removal section. It should be noted that after the film is formed on the wafer 200 at the first temperature (after film formation), if there is an opportunity for the formed film to be heated at a second temperature higher than the first temperature, heat treatment can be performed at this time.

[0235] (Alternative method 3)

[0236] like Figure 7 As shown, in another method 3, examples are illustrated of steps F and A, B and E, C and D being performed in different processing chambers (ex-situ). It should be noted that another method 3 also includes examples of steps F and A, B and E being performed in the same processing chamber (in-situ). Another method 3 can be achieved through methods such as... Figure 7 The substrate processing system shown is implemented by having four processing sections (four independent devices): a film-forming section, a heat treatment section, a specified processing section, a degradation section, and a removal section. Figure 7 In this process, steps F and A are performed in the film-forming section, steps B and E are performed in the heat treatment section and the specified treatment section, step C is performed in the deterioration section, and step D is performed in the removal section. It should be noted that if there is an opportunity for the film formed on the wafer 200 to be heated at a second temperature higher than the first temperature before, during (simultaneously with) the specified treatment, or after the specified treatment, the heat treatment can be performed at this time.

[0237] As described in alternative methods 1-3 above, when at least any one of steps F, A, B, E, C, and D is performed in the same processing chamber (in-situ), the chance of the wafer 200 being exposed to the atmosphere during each step is reduced, and the wafer 200 can be processed under vacuum, thus enabling stable substrate processing. Furthermore, if at least any one of steps F, A, B, E, C, and D is performed in different processing chambers (ex-situ), the temperature in each processing chamber can be preset to, for example, the processing temperature of each step or a temperature close to it, shortening the time required for temperature conditioning and improving production efficiency.

[0238] (Another method)

[0239] The above description illustrates an example of dry etching in step D, but wet etching can also be used in step D. That is, in step D, the deteriorated film formed on the surface of wafer 200 can be removed (etched) by wet etching. In wet etching, as a removing agent, for example, an aqueous solution containing HF (DHF) or a hot phosphoric acid aqueous solution can be used. Especially when the heat-treated film is a SiOC film containing C, and the heat-treated SiOC film is oxidized and deteriorated into a SiO film, it is preferable to use DHF as a removing agent for wet etching. This allows for efficient and selective removal of the deteriorated film.

[0240] In this method, by exposing the wafer 200 to DHF and a hot phosphoric acid aqueous solution, the deteriorated film formed on the surface of the wafer 200 can be removed (etched). Examples of methods for exposing the wafer 200 to DHF and a hot phosphoric acid aqueous solution include immersing the wafer 200 in the DHF and hot phosphoric acid aqueous solution. It should be noted that, in order to more effectively remove the deteriorated film formed on the surface of the wafer 200, both dry etching and wet etching can be performed in step D. This method achieves the same effect as the methods described above.

[0241] Furthermore, the above description illustrates the use of gases containing Si, C, and halogens, and gases containing O and H, in step A; however, this disclosure is not limited to these examples. For instance, in step A, an alkylene silane compound such as 1,4-disilobutane (SiH3CH2CH2SiH3, abbreviated as 1,4-DSB) and an oxidant such as O2 gas can be used to form a film on wafer 200. Alternatively, an alkylalkoxy silane such as diethoxymethylsilane and an oxidant such as O2 gas, added as needed, can be used to form a film on wafer 200. That is, as a raw material, a compound containing at least one of alkylene, alkyl, and alkoxy groups, and Si can be used; as an oxidant, an O-containing gas can be used. In these cases, the raw material and the oxidant can be supplied simultaneously, and a film can be formed using CVD. Even in this case, the same reaction as described above can occur in each step. In this method, the same effect as described above is also obtained.

[0242] The wafer 200 can have multiple regions of different materials as the first substrate, and it can also have multiple regions of different materials as the second substrate. In addition to the SiO and SiN films mentioned above, the regions constituting the first and second substrates can also be films containing semiconductor elements such as SiOCN, SiON, SiOC, SiC, SiCN, SiBN, SiBCN, SiBC, Si, Si, germanium (Ge), and silicon-germanium (SiGe), films containing metal elements such as TiN, W, Mo, Ru, Co, and Ni, amorphous carbon films (aC), and single-crystal Si (Si wafers). If a region is a region where a film-forming barrier layer can be formed, any region can be used as the first substrate. Conversely, if a region is a region where a film-forming barrier layer is difficult to form, any region can be used as the second substrate. This method achieves the same effect as the methods described above.

[0243] Regarding the processes used in each process, it is preferable to prepare them individually according to the processing content and store them in the storage device 121c in advance via an electrical communication line and an external storage device 123. Furthermore, it is preferable that 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 content. 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 the rapid initiation of each process.

[0244] The aforementioned process is not limited to newly manufactured 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 an electrical communication line and a recording medium containing the process. Alternatively, the input / output device 122 of the existing substrate processing apparatus can be operated to directly modify the existing process already installed in the substrate processing apparatus.

[0245] The above method describes an example of forming a film using a batch substrate processing apparatus that processes multiple substrates at a time. This disclosure is not limited to the above method; for example, it can also be suitably applied when forming a film using a monolithic substrate processing apparatus that processes one or several substrates at a time. Furthermore, the above method describes an example of forming a film using a substrate processing apparatus with a hot-wall type furnace. This disclosure is not limited to the above method; it can also be suitably applied when forming a film using a substrate processing apparatus with a cold-wall type furnace.

[0246] When using the substrate processing apparatus described above, each process can be performed under the same processing steps and conditions as described above to obtain the same effect as described above.

[0247] 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.

[0248] Example

[0249] <Example 1>

[0250] For the wafer, steps A, B, and C of the above-described processing sequence were performed to prepare the evaluation sample of Example 1. Specifically, a SiOC film was formed on the surface of the wafer, and the formed SiOC film was heat-treated to deteriorate (oxidize) the heat-treated SiOC film, thus preparing the evaluation sample of Example 1. The deterioration (oxidation) of the heat-treated SiOC film was performed using plasma-excited O2 gas under the first condition. The evaluation sample of Example 1 has a film on the surface of the wafer that has been deteriorated (oxidized) by treatment with plasma-excited O2 gas under the first condition. It should be noted that the processing conditions in each step when preparing the evaluation sample of Example 1 are specified conditions within the range of the processing conditions in each step described above.

[0251] <Example 2>

[0252] The degradation (oxidation) of the heat-treated SiOC film was replaced by a treatment using H2 gas + O2 gas. Except for this, the same procedures as for the evaluation sample of Example 1 were followed, performing steps A, B, and C on the wafer to produce the evaluation sample of Example 2. The evaluation sample of Example 2 has a film on the surface of the wafer that has been degraded (oxidized) by the treatment using H2 gas + O2 gas. It should be noted that the processing conditions in step C of the evaluation sample of Example 2 are within the specified range of the processing conditions in step C described above. Furthermore, the processing conditions in steps A and B of the evaluation sample of Example 2 are the same as those in steps A and B of the evaluation sample of Example 1.

[0253] <Example 3>

[0254] The degradation (oxidation) of the heat-treated SiOC film was replaced by treatment with plasma-excited O2 gas under condition 2. Except for this, the wafer was processed in the same manner as the evaluation sample of Example 1, performing steps A, B, and C to produce the evaluation sample of Example 3. The evaluation sample of Example 3 has a film on the surface of the wafer that has been degraded (oxidized) by treatment with plasma-excited O2 gas under condition 2. Condition 2 is a condition with weaker oxidizing power than condition 1. It should be noted that the processing conditions in step C of the evaluation sample of Example 3 are specified conditions within the range of the processing conditions in step C described above. Furthermore, the processing conditions in steps A and B of the evaluation sample of Example 3 are the same as those in steps A and B of the evaluation sample of Example 1, respectively.

[0255] <Comparative Example 1>

[0256] For a wafer, a thermal oxidation process was performed at a temperature above 800°C in an O-containing atmosphere to form a SiO film as a thermal oxidation film on the surface of the wafer, thus producing an evaluation sample for Comparative Example 1. The evaluation sample of Comparative Example 1 has a SiO film as a thermal oxidation film on the surface of the wafer.

[0257] <Comparative Example 2>

[0258] Steps A and B were performed, but step C was omitted. Otherwise, the same procedures were followed as for the preparation of the evaluation sample in Example 1 to prepare the evaluation sample of Comparative Example 2. The evaluation sample of Comparative Example 2 had a heat-treated SiOC film formed in steps A and B on the surface of the wafer. It should be noted that the processing conditions in steps A and B of the preparation of the evaluation sample of Comparative Example 2 were the same as those in steps A and B of the preparation of the evaluation sample of Example 1.

[0259] [Determination of Wet Etching Rate (WER)]

[0260] For each evaluation sample, a DHF-based wet etching process equivalent to step D was performed, and the WER of the respective films of the evaluation samples was measured. A 0.1% concentration of HF aqueous solution was used as the DHF. The measurement results are shown below. Figure 8 . Figure 8 The horizontal axis, from left to right, represents Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2, respectively; the vertical axis represents...

[0261] Depend on Figure 8 It can be seen that the WER of the membrane in the evaluation sample of Comparative Example 1 is a number. Approximately, in addition, the WER of the membrane in the evaluation sample of Comparative Example 2 was... Unable to be etched. In contrast, the WER of the films in the evaluation samples of Examples 1 to 3 all exceeded [a certain value]. It can be seen that the WER of the membranes in the evaluation samples of Comparative Examples 1 to 2 is higher.

[0262] In addition, by Figure 8 It is known that, regarding the SiOC film formed on the wafer surface in step A, the etch resistance is improved by the heat treatment based on step B (see Comparative Example 2), but it is easily removed in step D by the subsequent degradation (oxidation) based on step C (see Examples 1-3). Furthermore, it is known that the thermal oxide film has high etch resistance and is difficult to remove (see Comparative Example 1). Therefore, it is known that, for example, when a thermal oxide film and the SiOC film formed in step A exist on the wafer surface, by proceeding through steps B, C, and D, it is possible to selectively etch the film after the SiOC film has been heat-treated and degraded, while suppressing the etching of the thermal oxide film.

Claims

1. A substrate processing method, comprising the following steps: (a) A process of forming a carbon-containing film on a substrate by exposing the substrate to a film-forming agent at a first temperature; (b) A process of heat-treating the membrane at a second temperature higher than the first temperature; (c) The process of degrading the heat-treated membrane by exposing it to a degrading agent; and (d) The step of removing the deteriorated membrane by exposing it to a removal agent. in, In (c), the heat-treated membrane is oxidized to remove carbon from the membrane or to reduce the carbon concentration in the membrane.

2. The substrate processing method as described in claim 1, wherein, In (b), the etching resistance of the film is improved by the heat treatment. In (c), the film is degraded in a manner that reduces the etch resistance of the film after the heat treatment has improved its etch resistance. In (d), the degraded film is removed in a manner that reduces the etch resistance after the etch resistance has been improved by the heat treatment.

3. The substrate processing method as described in claim 1, wherein, (c) includes the step of supplying the modifier to the heat-treated membrane without plasma excitation.

4. The substrate processing method as described in claim 1, wherein, (c) includes the step of supplying the heat-treated membrane with plasma-excited degrader.

5. The substrate processing method as described in claim 1, wherein, In (c), an oxidizing agent is used as the deteriorating agent.

6. The substrate processing method as described in claim 1, wherein, The first temperature is below 100°C, and the second temperature is above 300°C.

7. The substrate processing method as described in claim 1, wherein, In (a), a cycle comprising the following steps is performed a specified number of times: (a1) a step of supplying raw material to the substrate as the film-forming agent; and (a2) a step of supplying an oxidant to the substrate as the film-forming agent.

8. The substrate processing method as described in claim 7, wherein, In at least one of (a1) and (a2), a catalyst is further supplied to the substrate.

9. The substrate processing method as described in claim 1, wherein, The membrane is a membrane containing silicon, carbon, and oxygen.

10. The substrate processing method as described in claim 1, wherein, After (a) and before (c), the process includes (e) a predetermined treatment of the substrate, the predetermined treatment including at least one of etching, film formation, and disposal.

11. The substrate processing method as described in claim 1, wherein, Prior to step (c), the substrate surface contains multiple films, including the film obtained after the heat treatment. In (c), the heat-treated membrane among the plurality of membranes is selectively degraded. In (d), the deteriorated membrane of the plurality of membranes is selectively removed.

12. The substrate processing method as described in claim 1, wherein, In the state prior to (a), the surface of the substrate has a first substrate and a second substrate. Prior to (a), the process includes (f) forming a film-forming barrier layer on the surface of the first substrate by supplying a modifier to the substrate. In (a), the film is formed on the surface of the second substrate.

13. The substrate processing method as described in claim 12, wherein, In (b), the heat treatment improves the etch resistance of the film.

14. The substrate processing method as described in claim 12, wherein, The substrate is etched after (a) and before (c).

15. The substrate processing method as described in claim 12, wherein, The substrate is subjected to a film-forming process after (a) and before (c).

16. The substrate processing method as described in claim 12, wherein, After (a) and before (c), the substrate is subjected to at least one of plasma treatment and thermal treatment.

17. The substrate processing method as claimed in claim 1, wherein, In (d), the deteriorated film is removed by at least one of dry etching and wet etching.

18. A method for manufacturing a semiconductor device, comprising: (a) A process of forming a carbon-containing film on a substrate by exposing the substrate to a film-forming agent at a first temperature; (b) A process of heat-treating the membrane at a second temperature higher than the first temperature; (c) A process of degrading the heat-treated membrane by exposing it to a degrading agent; and (d) The step of removing the deteriorated membrane by exposing it to a removal agent. In (c), the heat-treated membrane is oxidized to remove carbon from the membrane or to reduce the carbon concentration in the membrane.

19. A substrate processing system, comprising: (a) A film-forming portion comprising a carbon film is formed on the substrate by exposing the substrate to a film-forming agent at a first temperature; (b) A heat treatment section that heat-treats the membrane at a second temperature higher than the first temperature; (c) A degraded portion of the heat-treated membrane that is degraded by exposing it to a degrading agent; and (d) A removal section that removes the deteriorated membrane by exposing it to a removal agent. In (c), the heat-treated membrane is oxidized to remove carbon from the membrane or to reduce the carbon concentration in the membrane.

20. A computer-readable recording medium having a program recorded thereon that enables a substrate processing system to perform the following steps using a computer. (a) The step of forming a carbon-containing film on a substrate by exposing the substrate to a film-forming agent at a first temperature; (b) The step of heat-treating the membrane at a second temperature higher than the first temperature; (c) The step of degrading the heat-treated membrane by exposing it to a degrading agent; (d) The step of removing the deteriorated membrane by exposing it to a removal agent; and In (c), the heat-treated membrane is oxidized to remove carbon from the membrane or to reduce the carbon concentration in the membrane.

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