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

Abstract

The present invention relates to a substrate processing method, a semiconductor device manufacturing method, a computer-readable recording medium, and a substrate processing apparatus. A technique for suppressing film peeling of a laminated film attached to the inside of a processing container is provided. The present invention includes: (a) a step of forming a laminated film in which a first film containing nitrogen, oxygen, and a prescribed element and a second film containing nitrogen and having a different composition from the first film are laminated on a substrate in a processing container; and (b) a step of performing modification processing for bringing the composition of the second film in the laminated film attached to the inside of the processing container in (a) closer to the composition of the first film.

Description

Technical Field

[0001] This disclosure relates to substrate processing methods, semiconductor device manufacturing methods, recording media, and substrate processing apparatus. Background Technology

[0002] As a step in the manufacturing process of semiconductor devices, sometimes a step is performed to form a laminated film consisting of a first film and a second film stacked on a substrate within a processing container (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-193748 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, when a laminated film is formed on a substrate, a laminated film is sometimes also formed and attached inside the processing container, resulting in film peeling due to the difference in film stress between the first and second films in the laminated film attached inside the processing container.

[0008] The purpose of this disclosure is to provide a technique for suppressing the generation of membrane peeling in laminated membranes attached to a processing container.

[0009] Methods for solving problems

[0010] The following technology is provided according to one aspect of this disclosure, which possesses:

[0011] (a) A process of forming a laminated film consisting of a first film and a second film on a substrate within a processing container, wherein the first film contains nitrogen, oxygen, and a specified element, and the second film contains nitrogen and has a composition different from that of the first film; and

[0012] (b) A process of modifying the composition of the second membrane in the laminated membrane attached to the aforementioned processing container in (a) to be close to the composition of the first membrane.

[0013] The effects of the invention

[0014] According to this disclosure, it is possible to suppress the generation of membrane peeling in laminated membranes attached to the processing container. Attached Figure Description

[0015] Figure 1 This is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in one embodiment of this disclosure, showing the processing furnace 202 portion in a longitudinal sectional view.

[0016] Figure 2 This is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in one embodiment of this disclosure, showing the processing furnace 202 portion in a sectional view along line AA.

[0017] Figure 3 This is a schematic configuration diagram of the controller 121 of a substrate processing apparatus suitable for use in one embodiment of this disclosure, and is a block diagram illustrating the control system of the controller 121.

[0018] Figure 4 This is a diagram illustrating the flow of a substrate processing procedure as described in this disclosure.

[0019] Figure 5 This is a diagram illustrating an example of the processing sequence of the first membrane in one embodiment of this disclosure.

[0020] Figure 6 This is a diagram illustrating an example of the processing sequence of the second membrane in one embodiment of this disclosure.

[0021] Figure 7 (a) is a partial enlarged cross-sectional view of the surface of wafer 200. Figure 7 (b) is a partial enlarged cross-sectional view of the surface of wafer 200 after the first film is formed on wafer 200. Figure 7 (c) is a partially enlarged cross-sectional view of the surface of the wafer 200 after the second film is formed on the first film.

[0022] Figure 8 This is a partially enlarged cross-sectional view of the inner wall of a processing container with a laminated membrane consisting of alternating layers of a first membrane and a second membrane.

[0023] Figure 9 This is a graph showing the measurement results of the membrane stress of each membrane in a laminated membrane.

[0024] Explanation of reference numerals in the attached figures

[0025] 200 chips

[0026] 201 Processing Room Detailed Implementation

[0027] <One way of publishing this text>

[0028] The following is one approach to this published text, primarily referring to [reference needed]. Figures 1 to 8 The following explanation is provided. It should be noted that the accompanying drawings used in the following explanation 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 elements in multiple drawings are not necessarily consistent with each other.

[0029] (1) Composition of substrate processing device

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

[0031] 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 with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and is formed into a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing component. The reaction tube 203 is also vertically mounted like the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow part of the processing container. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate. The wafer 200 is processed within the processing chamber 201, i.e., within the processing container.

[0032] Inside the processing chamber 201, nozzles 249a and 249b, serving as a first supply section and a second supply section, are respectively provided through the side wall of the manifold 209. These nozzles are also referred to as the first nozzle and the second nozzle. The nozzles 249a and 249b are made of heat-resistant materials such as quartz or SiC. Gas supply pipes 232a and 232b are connected to the nozzles 249a and 249b. The nozzles 249a and 249b are separate nozzles and are arranged adjacent to each other.

[0033] On gas supply pipes 232a and 232b, mass flow controllers (MFCs) 241a and 241b, serving as flow controllers (flow control units), and valves 243a and 243b, serving as on / off valves, are sequentially installed from the upstream side of the airflow. A gas supply pipe 232f is connected downstream of valve 243a of gas supply pipe 232a. Gas supply pipes 232c to 232e are connected downstream of valve 243b of gas supply pipe 232b. On gas supply pipes 232c to 232f, MFCs 241c to 241f and valves 243c to 243f are sequentially installed from the upstream side of the airflow. Gas supply pipes 232a to 232f are made of a metal material such as SUS.

[0034] like Figure 1 , Figure 2 As shown, nozzles 249a and 249b are respectively provided vertically from the lower part of the inner wall of the reaction tube 203 along the upper part of the annular space between the inner wall of the reaction tube 203 and the wafer 200 in a way that faces upwards towards the arrangement direction of the wafer 200, within the annular space between the inner wall of the reaction tube 203 and the wafer 200. That is, nozzles 249a and 249b are respectively provided along the wafer arrangement area, in a region that horizontally surrounds the wafer arrangement area on the side of the wafer arrangement area where the wafers 200 are arranged. Gas supply holes 250a and 250b are respectively opened towards the center of the wafer 200 in a way that faces upwards, enabling gas to be supplied to the wafer 200. A plurality of gas supply holes 250a and 250b are provided in the reaction tube 203 from the lower part to the upper part.

[0035] Raw material gas containing semiconductor or metal elements is supplied from gas supply pipe 232a to processing chamber 201 via MFC 241a, valve 243a, and nozzle 249a.

[0036] Oxygen (O) gas is supplied into the processing chamber 201 from the gas supply pipe 232b via MFC 241b, valve 243b, and nozzle 249b.

[0037] A gas containing at least one of the specified elements, carbon (C) and boron (B), is supplied from gas supply pipe 232c to processing chamber 201 via MFC 241c, valve 243c, and nozzle 249a.

[0038] Nitrogen (N) gas is supplied into the processing chamber 201 from the gas supply pipe 232d via MFC 241d, valve 243d, and nozzle 249b.

[0039] Inactive gas is supplied to the treatment chamber 201 through gas supply pipes 232e and 232f via MFCs 241e and 241f, valves 243e and 243f, gas supply pipes 232a and 232b, and nozzles 249a and 249b, respectively. The inactive gas functions as a purge gas, carrier gas, or dilution gas.

[0040] The main components of the processing gas supply system (including raw material gas supply system, nitrogen-containing gas supply system, oxygen-containing gas supply system, and gas supply system containing specified elements) consist of gas supply pipes 232a-232d, MFCs 241a-241d, and valves 243a-243d. The main components of the inactive gas supply system consist of gas supply pipes 232e-232f, MFCs 241e-241f, and valves 243e-243f.

[0041] Any or all of the aforementioned gas supply systems can be configured as an integrated gas supply system 248, comprising valves 243a-243f, MFCs 241a-241f, etc. The integrated gas supply system 248 is connected to gas supply pipes 232a-232f, and is configured to control the supply of various gases to the gas supply pipes 232a-232f using the controller 121 described later, i.e., the opening and closing of valves 243a-243f, and the flow regulation using MFCs 241a-241f. The integrated gas supply system 248 is configured as an integrated unit, either integral or modular, allowing for the assembly and disassembly of gas supply pipes 232a-232f at the integrated unit level, and enabling maintenance, replacement, and addition of the integrated gas supply system 248 at the integrated unit level.

[0042] Below the side wall of the reaction tube 203, an exhaust port 231a is provided for exhausting the atmosphere inside the processing chamber 201. The exhaust port 231a may also be provided from the lower part of the side wall of the reaction tube 203 along the upper part, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246, which is a vacuum exhaust device, is connected to the exhaust pipe 231 via a pressure sensor 245, which is a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201, and an APC (AutoPressure Controller) valve 244, which is a pressure regulator (pressure regulating unit). The APC valve 244 is configured to open and close when the vacuum pump 246 is operating, thereby enabling vacuum exhaust and vacuum exhaust stop in the processing chamber 201. Furthermore, by adjusting the valve opening based on the pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating, the pressure inside the processing chamber 201 can be adjusted. The exhaust system mainly consists of exhaust pipe 231, APC valve 244, and pressure sensor 245. The vacuum pump 246 can also be considered as part of the exhaust system.

[0043] 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. On the upper surface of the sealing cover 219, an O-ring 220b, serving as a sealing member, 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, made of a metal material such as SUS, 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 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 conveying device (conveying mechanism) that moves the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219.

[0044] 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 abuts against the lower end of the manifold 209. The opening and closing actions (lifting, rotating, etc.) of the gate 219s are controlled by a gate opening and closing mechanism 115s.

[0045] The support boat 217, serving as the support substrate, is configured to support multiple wafers 200 (e.g., 25 to 200) arranged horizontally and aligned at their centers in the vertical direction in a multi-layered manner. Specifically, the support boat 217 is configured to arrange multiple wafers 200 horizontally and spaced apart in the vertical direction. The support boat 217 is made of a heat-resistant material such as quartz or SiC. The lower part of the support boat 217 supports a heat-insulating plate 218 made of a heat-resistant material such as quartz or SiC in multiple layers. The support boat 217 is configured to support multiple wafers 200 individually.

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

[0047] like Figure 3 As shown, the controller 121, serving as the control unit (control 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.

[0048] Storage device 121c is composed of, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. Storage device 121c stores in a readable manner a control program that controls the operation of the substrate processing apparatus, a process flow that describes the steps and conditions of the processing described later, etc. The process flow is a combination of steps that can be executed in the substrate processing apparatus by the controller 121 to obtain a predetermined result, and functions as a program. 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.

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

[0050] CPU 121a is configured to read and execute control programs from storage device 121c, and to read processes from storage device 121c based on input of operation commands from input / output device 122. CPU 121a is configured to control the following actions according to the read processes: flow regulation of various gases using MFCs 241a to 241g, opening and closing of valves 243a to 243g, 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, etc.

[0051] 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, hard disks such as HDDs, optical disks such as CDs, optical disks such as MO drives, USB storage devices, and semiconductor storage devices such as SSDs. The storage device 121c and the external storage device 123 are configured in the form of a computer-readable recording medium. 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 providing a program to a computer may also be done without using the external storage device 123, but using communication means such as the Internet or dedicated lines.

[0052] (2) Substrate processing process

[0053] An example of the following processing sequence will be described: Using the above-described substrate processing apparatus, as a step in the manufacturing process of a semiconductor device, a laminated film consisting of a first film and a second film is formed on a wafer 200, which serves as a substrate within a processing container, and a modification process is performed to make the composition of the second film attached to the laminated film within the processing container approximate the composition of the first film. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0054] The following steps are performed in the processing sequence of this method:

[0055] Step A: A laminated film is formed on the wafer 200 within the processing container, consisting of a first film containing N, O, and specified elements, and a second film containing N but with a different composition from the first film; and

[0056] Step B involves a modification treatment that makes the composition of the second membrane in the laminated membrane attached to the processing container in step A close to the composition of the first membrane.

[0057] In this method, in step A, a first film (first film formation process) is formed by supplying a raw material gas, a nitrogen-containing gas, an oxygen-containing gas, and a gas containing a specified element onto the wafer 200, and a second film (second film formation process) is formed by supplying the raw material gas and the nitrogen-containing gas, thereby forming a laminated film of the first and second films. Then, in step B, an oxygen-containing gas is supplied to perform a modification process that makes the composition of the second film in the laminated film attached to the processing container close to the composition of the first film.

[0058] In the first film formation process of step A in this method, such as Figure 5 The processing sequence shown forms the first film on wafer 200 by performing the following steps non-simultaneously a predetermined number of times (n times, where n is an integer greater than or equal to 1):

[0059] Step A1: Supply raw material gas to the wafer 200 in the processing container;

[0060] Step A2: Supply a gas containing a specified element to the wafer 200 inside the processing container;

[0061] Step A3, supplying O-containing gas to the wafer 200 inside the processing container; and

[0062] Step A4: Supply N-containing gas to the wafer 200 in the processing container.

[0063] In the second film formation process of step A in this method, such as Figure 6 The processing sequence shown forms the second membrane on the first membrane by repeating the following steps non-simultaneously a predetermined number of times (m times, where m is an integer greater than or equal to 1):

[0064] Step a1, supplying raw material gas to the wafer 200 inside the processing container; and

[0065] Step a2: Supply N-containing gas to the wafer 200 inside the processing container.

[0066] For convenience, the above processing sequence is sometimes shown as follows in this specification. The same wording is also used in the following descriptions of other methods, variations, etc.

[0067] First membrane formation process: (raw material gas → gas containing specified elements → gas containing O → gas containing N) × n

[0068] Second film formation process: (raw material gas → nitrogen-containing gas) × m

[0069] The term "wafer" as used in this specification includes both the wafer itself and a laminate of a wafer and a specified layer or film formed on its surface. The term "surface of the wafer" as used in this specification includes both the surface of the wafer itself and the surface of a specified layer, etc., formed on the wafer. The phrase "forming a specified layer on the wafer" as used in this specification 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" as used in this specification has the same meaning as the term "wafer."

[0070] (2-1) Film Formation Treatment

[0071] First, an example of the sequence of the first film forming process for forming a first film on wafer 200 will be described. Next, an example of the sequence of the second film forming process for forming a second film on the first film will be described.

[0072] (Chip filling)

[0073] Multiple wafers 200 are loaded (wafer filling) into the crystal boat 217. Then, the gate 219s is moved by the gate opening and closing mechanism 115s to open the lower end opening of the manifold 209 (gate opening).

[0074] (Loading Crystal Boat)

[0075] Then, as Figure 1 As shown, the crystal boat 217, which supports multiple wafers 200, is lifted by the 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 via the O-ring 220b.

[0076] (Pressure regulation and temperature regulation)

[0077] After the crystal boat is loaded, vacuum pump 246 is used to exhaust the vacuum (pressure reduction exhaust) in the processing chamber 201, i.e., the space where the wafer 200 exists, to achieve the desired pressure (vacuum). At this time, the pressure in the processing chamber 201 is measured by pressure sensor 245, and APC valve 244 is controlled based on the measured pressure information (pressure regulation). Additionally, the wafer 200 in the processing chamber 201 is heated by heater 207 to achieve the desired processing temperature. At this time, the energization state 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 (temperature regulation). Furthermore, the wafer 200 is rotated using rotation mechanism 267. The operation of vacuum pump 246, heating of wafer 200, and rotation are all performed continuously, at least until the processing of wafer 200 is completed.

[0078] (First film formation treatment)

[0079] Then, perform the following steps A1 to A4 in sequence.

[0080] [Step A1]

[0081] In step A1, raw material gas is supplied to the wafer 200 in the processing chamber 201.

[0082] Specifically, valve 243a is opened, allowing raw material gas to flow into the gas supply pipe 232a. The flow rate of the raw material gas is regulated by MFC 241a, supplied to the processing chamber 201 via nozzle 249a, and exhausted from the exhaust port 231a. At this time, raw material gas is supplied to the wafer 200 from the side (raw material gas supply). At this time, valves 243e and 243f are opened, supplying inactive gas into the processing chamber 201 via nozzles 249a and 249b, respectively. It should be noted that in the methods shown below, the supply of inactive gas to the processing chamber 201 may not be performed.

[0083] As a processing condition in this step, the following examples can be given:

[0084] Processing temperature: 250–800℃, preferably 400–700℃

[0085] Processing pressure: 1–2666 Pa, preferably 67–1333 Pa

[0086] Raw material gas supply flow rate: 0.01–2 slm, preferably 0.1–1 slm

[0087] Raw material gas supply time: 1–120 seconds, preferably 1–60 seconds

[0088] Inactive gas supply flow rate (per gas supply pipe): 0-10 slm.

[0089] It should be noted that the numerical range "250~800℃" in this specification refers to the inclusion of both the lower and upper limits within that range. Therefore, "250~800℃" means "above 250℃ and below 800℃". The same applies to other numerical ranges. Furthermore, the processing temperature in this specification refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. Additionally, the gas supply flow rate of 0 slm indicates that the gas is not supplied. The same applies to the following descriptions.

[0090] Under the above processing conditions, by supplying a chlorosilane-based gas, for example, to the wafer 200 as a raw material gas, a Si-containing layer containing Cl is formed on the outermost surface of the wafer 200, which serves as a substrate. The Si-containing layer containing Cl is formed by the following methods: physical adsorption and chemisorption of chlorosilane-based gas molecules onto the outermost surface of the wafer 200; physical adsorption and chemisorption of molecules from a portion of the decomposed chlorosilane-based gas onto the outermost surface of the wafer 200; deposition of Si formed from the thermal decomposition of the chlorosilane-based gas onto the outermost surface of the wafer 200; and so on. The Si-containing layer containing Cl can be an adsorption layer (physical adsorption layer, chemisorption layer) of chlorosilane-based gas molecules and molecules from a portion of the decomposed chlorosilane-based gas, or it can be a deposited layer of Si containing Cl. In this specification, the Si-containing layer containing Cl is also simply referred to as the Si-containing layer. It should be noted that, under the above processing conditions, physical adsorption and chemical adsorption of chlorosilane gas molecules and molecules of substances derived from the decomposition of chlorosilane gases onto the outermost surface of the wafer 200 are dominantly (preferably) generated, while Si deposition formed by the thermal decomposition of chlorosilane gases is generated in small amounts or almost not at all. That is, under the above processing conditions, the Si-containing layer overwhelmingly includes an adsorption layer (physical adsorption layer and chemical adsorption layer) of chlorosilane gas molecules and molecules of substances derived from the decomposition of chlorosilane gases, and includes, or almost does not include, a Si deposition layer containing Cl.

[0091] After the Si-containing layer is formed, valve 243a is closed to stop the supply of raw material gas to the processing chamber 201. Then, the processing chamber 201 is evacuated to remove any remaining gases. At this time, valves 243e and 243f are kept open, and inactive gas is supplied to the processing chamber 201 and exhausted from the exhaust port 231a. The processing chamber 201 is then purged using the inactive gas.

[0092] Examples of purging treatment conditions can be shown as follows:

[0093] Processing pressure: 1~20Pa

[0094] Inactive gas supply flow rate (per gas supply pipe): 0.05~20slm

[0095] Inactive gas supply time: 1 to 200 seconds, preferably 1 to 40 seconds.

[0096] Other processing conditions are the same as those when the raw material gas is supplied.

[0097] As a feed gas, for example, a silane-based gas containing silicon (Si), which is the main element constituting the film formed on the wafer 200, can be used. As a silane-based gas, for example, a gas containing halogens and Si, i.e., a halosilane-based gas, can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As a halosilane-based gas, for example, the aforementioned chlorosilane-based gas containing Cl and Si can be used.

[0098] As feedstock gases, chlorosilane-based gases such as monochlorosilane (SiH3Cl, abbreviated as MCS), dichlorosilane (SiH2Cl2, abbreviated as DCS), trichlorosilane (SiHCl3, abbreviated as TCS), tetrachlorosilane (SiCl4, abbreviated as 4CS), hexachlorodisilane (Si2Cl6, abbreviated as HCDS), and octachlorotrisilane (Si3Cl8, abbreviated as OCTS) can be used. One or more of these gases can be used as feedstock gases.

[0099] In addition to chlorosilane-based gases, other gaseous raw materials such as tetrafluorosilane (SiF4) and difluorosilane (SiH2F2), bromosilane (SiBr4) and dibromosilane (SiH2Br2), and iodosilane (SiI4) and diiodosilane (SiH2I2) can also be used as raw materials. One or more of these gases can be used as raw materials.

[0100] In addition to these, gases containing amino groups and Si, i.e., aminosilane gases, can also be used as feedstock gases. An amino group refers to a monovalent functional group obtained by removing hydrogen (H) from ammonia, primary amines, or secondary amines, and can be represented as -NH2, -NHR, or -NR2. It should be noted that R represents an alkyl group, and the two Rs in -NR2 can be the same or different.

[0101] As feedstock gases, for example, tetra(dimethylamino)silane (Si[N(CH3)2]4, abbreviated as 4DMAS) gas, tri(dimethylamino)silane (Si[N(CH3)2]3H, abbreviated as 3DMAS) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviated as BDEAS) gas, bis(tert-butylamino)silane (SiH2[NH(C4H9)]2, abbreviated as BTBAS) gas, and (diisopropylamino)silane (SiH3[N(C3H7)2], abbreviated as DIPAS) gas, etc., can be used. One or more of the above-mentioned gases can be used as feedstock gases.

[0102] These aspects are also true in step a1 described later.

[0103] As inert gases, rare gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), xenon (Xe), krypton (Kr), and radon (Rn) can be used. One or more of these gases can be used as inert gases. This also applies to the steps described later.

[0104] [Step A2]

[0105] After step A1 is completed, a gas containing a specified element is supplied to the wafer 200 in the processing chamber 201, that is, to the Si-containing layer formed on the wafer 200.

[0106] Specifically, valve 243c is opened, allowing gas containing a specified element to flow into gas supply pipe 232c. The flow rate of this gas is regulated by MFC 241c, supplied to processing chamber 201 via nozzle 249a, and exhausted from exhaust port 231a. At this time, gas containing the specified element is supplied to wafer 200 from the side (gas supply containing the specified element). Alternatively, valves 243e and 243f can remain open, supplying inactive gas to processing chamber 201 via nozzles 249a and 249b, respectively.

[0107] As a processing condition in this step, the following examples can be given:

[0108] Processing pressure: 1–4000 Pa, preferably 1–3000 Pa

[0109] Gas supply flow rate containing specified elements: 0.1~10slm

[0110] The gas supply time containing the specified elements is 1 to 120 seconds, preferably 1 to 60 seconds.

[0111] The other processing conditions are the same as those in step A1 when supplying the raw material gas.

[0112] By supplying a carbon (C) gas to the wafer 200 under the aforementioned conditions as a gas containing a specified element, at least a portion of the Si-containing layer formed on the wafer 200 is carbonized (modified). As a result, a silicon carbide layer (SiC layer) is formed on the outermost surface of the wafer 200, which serves as a substrate, as a layer formed by carbonizing the Si-containing layer, i.e., a layer containing Si and C. During the formation of the SiC layer, impurities such as Cl contained in the Si-containing layer are converted into a gaseous substance containing at least Cl during the modification reaction of the Si-containing layer caused by the gas containing the specified element, and are discharged from the processing chamber 201. Thus, the SiC layer becomes a layer with fewer impurities such as Cl compared to the Si-containing layer.

[0113] After the SiC layer is formed, valve 243c is closed to stop the supply of gas containing the specified elements to the processing chamber 201. The gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 through the same processing steps as the purging in step A1 (purging).

[0114] As a gas containing the specified element, a carbon-containing gas can be used, for example. As a carbon-containing gas, hydrocarbon-based gases such as propylene (C3H6), ethylene (C2H4), and acetylene (C2H2) can be used, for example. As a gas containing the specified element, one or more of the above-mentioned gases can be used.

[0115] [Step A3]

[0116] After step A2 is completed, O-containing gas is supplied to the wafer 200 in the processing chamber 201, that is, the SiC layer formed on the wafer 200.

[0117] Specifically, valve 243b is opened, allowing O-containing gas to flow into gas supply pipe 232b. The flow rate of the O-containing gas is regulated by MFC 241b, supplied to processing chamber 201 via nozzle 249b, and exhausted from exhaust port 231a. At this time, O-containing gas is supplied to wafer 200 from the side (O-containing gas supply). Alternatively, valves 243e and 243f can remain open, supplying inactive gas to processing chamber 201 via nozzles 249a and 249b, respectively.

[0118] As a processing condition in this step, the following examples can be given:

[0119] Processing pressure: 1–4000 Pa, preferably 1–3000 Pa

[0120] O-containing gas supply flow rate: 0.1~10slm

[0121] O-containing gas supply time: 1-120 seconds, preferably 1-60 seconds.

[0122] The other processing conditions are the same as those in step A1 when supplying the raw material gas.

[0123] By supplying an O-containing gas to the wafer 200 under the aforementioned conditions, at least a portion of the SiC layer formed on the wafer 200 is oxidized (modified). As a result, a silicon carbide oxide layer (SiOC layer) is formed on the outermost surface of the wafer 200, which serves as the substrate, as a layer formed by the oxidation of the SiC layer, i.e., a layer containing Si, O, and C. During the formation of the SiOC layer, impurities such as Cl contained in the SiC layer are converted into gaseous substances containing at least Cl during the modification reaction of the SiC layer caused by the O-containing gas, and are discharged from the processing chamber 201. Thus, the SiOC layer becomes a layer with fewer impurities such as Cl compared to the SiC layer.

[0124] After the SiOC layer is formed, valve 243b is closed to stop the supply of O-containing gas to the processing chamber 201. The gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 through the same processing steps as the purging in step A1 (purging).

[0125] As the O-containing gas, examples include oxygen (O2), ozone (O3), water vapor (H2O), nitric oxide (NO), and nitrous oxide (N2O). One or more of these can be used as the O-containing gas. This also applies to step b described later.

[0126] [Step A4]

[0127] After step A3 is completed, nitrogen-containing gas is supplied to the wafer 200 in the processing chamber 201, that is, the SiOC layer formed on the wafer 200.

[0128] Specifically, valve 243d is opened, allowing nitrogen-containing gas to flow into the gas supply pipe 232d. The flow rate of the nitrogen-containing gas is regulated by MFC 241d, supplied to the processing chamber 201 via nozzle 249b, and exhausted from the exhaust port 231a. At this time, nitrogen-containing gas is supplied to the wafer 200 from the side (nitrogen gas supply). Alternatively, valves 243e and 243f can remain open, supplying inactive gas to the processing chamber 201 via nozzles 249a and 249b, respectively.

[0129] As a processing condition in this step, the following examples can be given:

[0130] Processing pressure: 1–4000 Pa, preferably 1–3000 Pa

[0131] Nitrogen-containing gas supply flow rate: 0.1–10 slm

[0132] Nitrogen gas supply time: 1–120 seconds, preferably 1–60 seconds.

[0133] The other processing conditions are the same as those in step A1 when supplying the raw material gas.

[0134] By supplying nitrogen-containing gas to the wafer 200 under the aforementioned conditions, at least a portion of the SiOC layer formed on the wafer 200 is nitrided (modified). As a result, a silicon oxide carbon nitride layer (SiOCN layer) is formed on the outermost surface of the wafer 200, which serves as the substrate, to form a layer containing Si, O, C, and N, which is a layer formed by nitriding the SiOC layer. During the formation of the SiOCN layer, impurities such as Cl contained in the SiOC layer are converted into a gaseous substance containing at least Cl during the modification reaction of the SiOC layer caused by the nitrogen-containing gas, and are discharged from the processing chamber 201. Thus, the SiOCN layer becomes a layer with fewer impurities such as Cl compared to the SiOC layer.

[0135] After the SiOCN layer is formed, valve 243d is closed to stop the supply of N-containing gas to the processing chamber 201. The gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 by the same processing steps as the purging in step A1 (purging).

[0136] As the nitrogen-containing gas, hydrogen nitride-based gases such as ammonia (NH3), diazoxide (N2H2), hydrazine (N2H4), and N3H8 can be used. One or more of these gases can be used as the nitrogen-containing gas. This also applies to step a2 described later.

[0137] [The prescribed number of times the cycle is to be implemented]

[0138] By performing steps A1 to A4 of the above process asynchronously a predetermined number of times (n times, where n is an integer greater than or equal to 1), the surface of wafer 200 is used as a substrate. On this substrate, a silicon oxide carbon nitride film (SiOCN film) of a predetermined thickness containing O, N, a predetermined element such as C, and a semiconductor element such as Si is formed as the first film (see [link to documentation]). Figure 7 of (a), Figure 7 (b)). The above cycle is preferably repeated multiple times. That is, it is preferable that the thickness of the SiOCN layer formed in each cycle is thinner than the desired film thickness, and the above cycle is repeated multiple times until the thickness of the SiOCN film formed by stacking SiOCN layers becomes the desired thickness.

[0139] (Second film formation treatment)

[0140] Then, perform the following steps A1 and A2 in sequence.

[0141] [Step a1]

[0142] In step a1, a raw material gas is supplied to the wafer 200, i.e., the first film formed on the wafer 200, within the processing chamber 201, using the same processing steps and conditions as in step A1 above (raw material gas supply). This forms a Si-containing layer on the first film. After the Si-containing layer is formed, the supply of raw material gas to the processing chamber 201 is stopped, and any remaining gases or other contaminants in the processing chamber 201 are removed from the processing chamber 201 through a processing step identical to the purging process in step A1 (purging).

[0143] [Step a2]

[0144] After step a1, N-containing gas is supplied to the wafer 200, i.e., the Si-containing layer formed on the first film on the wafer 200, within the processing chamber 201, using the same processing steps and conditions as in step A1 above (N-containing gas supply). As a result, at least a portion of the Si-containing layer formed on the first film is nitrided (modified). Consequently, a silicon nitride layer (SiN layer) is formed on the first film, which serves as a substrate, to form a layer containing both Si and N, i.e., a layer formed by nitriding the Si-containing layer. During the formation of the SiN layer, impurities such as Cl contained in the Si-containing layer undergo a modification reaction of the SiN layer caused by the N-containing gas, constituting a gaseous substance containing at least Cl, and is discharged from the processing chamber 201. Thus, the SiN layer becomes a layer with fewer impurities such as Cl compared to the Si-containing layer.

[0145] After the SiN layer is formed, the supply of N-containing gas to the processing chamber 201 is stopped, and the gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 by the same processing steps as the purging in step A1 (purging).

[0146] [The prescribed number of times the cycle is to be implemented]

[0147] By performing steps A1 and A2 asynchronously a predetermined number of times (m times, where m is an integer greater than or equal to 1), the surface of the first film is used as a substrate, and a silicon nitride film (SiN film) of a predetermined thickness containing N and a semiconductor element such as Si can be formed on this substrate to form the second film (see [link to documentation]). Figure 7 (c)). The second film is a film that substantially does not contain the O and specified elements contained in the first film, and its composition and structure differ from those of the first film. The above cycle is preferably repeated multiple times. That is, it is preferable that the thickness of the SiN layer formed in each cycle is thinner than the desired film thickness, and the above cycle is repeated multiple times until the thickness of the SiN film formed by stacking SiN layers becomes the desired thickness.

[0148] The thickness of the second membrane formed by the above processing steps and conditions is thinner than the thickness of the first membrane, which serves as the substrate of the second membrane.

[0149] (Post-purge and atmospheric pressure recovery)

[0150] After the processing of forming a laminated film of the desired thickness, consisting of a first film and a second film, on the wafer 200 is completed, an inert gas is supplied as a purge gas into the processing chamber 201 from nozzles 249a and 249b, and exhaust is performed from the 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 the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0151] (Jingzhou Unloading)

[0152] 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 opening of the manifold 209 by the gate 219s via the O-ring 220c (gate closing).

[0153] (Chip removal)

[0154] After the wafer has cooled, the processed wafer 200, which has been cooled to a specified temperature at which it can be removed, is removed from the wafer boat 217 (wafer removal).

[0155] Thus, the process of forming a laminated film consisting of the first film and the second film on the wafer 200 is completed. This process is performed a predetermined number of times (at least once).

[0156] (2-2) Modification treatment of laminated films

[0157] If the first and second film-forming processes described above are performed, the laminated film of the first and second films will also adhere to the surface of the components inside the processing container, such as the inner wall of the reaction tube 203, the surface of the crystal boat 217, etc. Figure 8The diagram schematically shows a partially enlarged cross-sectional view of the inner wall of the processing container, specifically the inner wall of the reaction tube 203, to which a laminated membrane, composed of alternating layers of the first and second membranes, is attached by alternatingly repeating the first and second membrane formation processes. Due to the different stresses generated in the first and second membranes, the formation of the laminated membrane sometimes leads to cracks in the laminated membrane due to the stress difference between the first and second membranes, causing the membrane to peel off from the surface of the component and generating foreign matter (particles) inside the furnace. Therefore, after the laminated membrane is formed, at predetermined time points, the laminated membrane attached to the processing container is modified, and a maintenance treatment is performed to reduce (mitigate) the stress difference between the first and second membranes.

[0158] The following describes the modification treatment of the laminated film attached to the processing container. In the following description, the operation of each part constituting the substrate processing apparatus is also controlled by the controller 121.

[0159] (Loading the empty crystal boat)

[0160] The gate 219s is moved by the gate opening and closing mechanism 115s to open the lower end opening of the manifold 209 (gate opening). Then, the empty crystal boat 217 with the second film attached to its surface, i.e., the crystal boat 217 without holding the wafer 200, is lifted by the crystal boat lift 115 and moved into the processing container with the second film attached to its surface, i.e., the processing chamber 201 (empty crystal boat loading). In this state, the sealing cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0161] (Pressure regulation and temperature regulation)

[0162] After the empty crystal boat is loaded, vacuum pump 246 is used to exhaust the vacuum (pressure reduction exhaust) in the processing chamber 201 to achieve the desired pressure (vacuum level). At this time, the pressure in the processing chamber 201 is measured by pressure sensor 245, and the APC valve 244 is controlled based on this pressure information (pressure regulation). Additionally, the processing chamber 201 is heated using heater 207 to achieve the desired processing temperature. At this time, the energization state 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 (temperature regulation). Furthermore, the empty crystal boat 217 is rotated using rotating mechanism 254. The operation of vacuum pump 246, heating in the processing chamber 201, and rotation of crystal boat 217 continue until the modification treatment of the laminated film is completed. It should be noted that crystal boat 217 may also remain stationary.

[0163] (Modification treatment)

[0164] Then, perform step b below.

[0165] [Step b]

[0166] In step b, the laminated membrane in the processing container is supplied with, for example, O-containing gas (O-containing gas supply) through the same processing steps as in step A3 above. This oxidizes the laminated membrane in the processing container. After the oxidation process is completed, the supply of raw material gas to the processing chamber 201 is stopped, and any remaining gas or other contaminants in the processing chamber 201 are removed from the processing chamber 201 through a purging process identical to that in step A1 (purging).

[0167] As a processing condition in this step, the following examples can be given:

[0168] Processing temperature: 300–750℃, preferably 500–650℃

[0169] Processing pressure: 30–1200 Pa, preferably 1000–1200 Pa

[0170] O-containing gas supply flow rate: 1–10 slm, preferably 3–6 slm

[0171] O-containing gas supply time: 10-60 minutes, preferably 20-40 minutes.

[0172] The other processing conditions are the same as those in step A1 when supplying the raw material gas.

[0173] By supplying an O-containing gas to the laminated membranes within the processing container under the aforementioned conditions, at least a portion of either the first membrane (SiOCN membrane) or the second membrane (SiN membrane) in the laminated membrane is oxidized (modified). Specifically, by supplying an O-containing gas into the processing container, the second membrane is oxidized and modified into a silicon oxynitride (SiON) membrane, and the first membrane is oxidized, further absorbing O to modify it into a high-O-concentration (oxygen-rich) SiOCN membrane. Thus, by making the composition of the second membrane close to that of the first membrane, the membrane stress difference between the first and second membranes can be reduced.

[0174] If the processing temperature is below 300℃, the activation of the O-containing gas is insufficient, sometimes making the modification (oxidation) process difficult. By raising the processing temperature to above 300℃, the activation of the O-containing gas is made sufficient, allowing the modification (oxidation) process to proceed. By raising the processing temperature to above 500℃, the O-containing gas is further activated, enabling the modification (oxidation) process to proceed efficiently.

[0175] If the processing temperature exceeds 750℃, the activation of oxygen-containing gas becomes excessive, sometimes making modification (oxidation) difficult. By setting the processing temperature below 750℃, the activity of oxygen-containing gas is appropriately suppressed, allowing modification (oxidation) to proceed. By setting the processing temperature below 650℃, the activity of oxygen-containing gas is more appropriately suppressed, enabling modification (oxidation) to proceed efficiently.

[0176] If the processing pressure is less than 30 Pa, the activation of the O-containing gas is insufficient, sometimes making the modification (oxidation) process difficult. By increasing the processing pressure to 30 Pa or higher, the activation of the O-containing gas becomes sufficient, allowing the modification (oxidation) process to proceed. By increasing the processing pressure to 1000 Pa or higher, the O-containing gas is further activated, enabling the modification (oxidation) process to proceed efficiently.

[0177] If the processing pressure exceeds 1200 Pa, the activation of the O-containing gas is excessive, sometimes making the modification (oxidation) process difficult. By setting the processing pressure below 1200 Pa, the activity of the O-containing gas is appropriately suppressed, allowing the modification (oxidation) process to proceed.

[0178] If the O-containing gas supply flow rate is less than 1 slm, the modification (oxidation) treatment may be difficult to carry out. By increasing the O-containing gas supply flow rate to 1 slm or more, the modification (oxidation) treatment can be carried out. By increasing the O-containing gas supply flow rate to 3 slm or more, the modification (oxidation) treatment can be carried out efficiently.

[0179] If the oxygen-containing gas supply flow rate exceeds 10 slm, over-processing (oxidation) may occur. This can also lead to increased gas costs. By reducing the oxygen-containing gas supply flow rate to below 10 slm, over-processing (oxidation) can be suppressed, thus avoiding increased gas costs. Furthermore, reducing the oxygen-containing gas supply flow rate to below 6 slm allows for more effective suppression of over-processing (oxidation), reliably preventing increased gas costs.

[0180] If the oxygen-containing gas supply time is less than 10 minutes, the modification (oxidation) treatment may be difficult to carry out. By increasing the oxygen-containing gas supply time to 10 minutes or more, the modification (oxidation) treatment can be carried out. By increasing the oxygen-containing gas supply time to 20 minutes or more, the modification (oxidation) treatment can be carried out efficiently.

[0181] If the oxygen-containing gas supply time exceeds 60 minutes, over-processing of the modification (oxidation) process may occur. Furthermore, this can sometimes lead to a decrease in productivity. By limiting the oxygen-containing gas supply time to 60 minutes or less, over-processing of the modification (oxidation) process can be suppressed, thus preventing a decrease in productivity. By limiting the oxygen-containing gas supply time to 40 minutes or less, over-processing of the modification (oxidation) process can be more appropriately suppressed, thus more reliably preventing a decrease in productivity.

[0182] (Post-purge and atmospheric pressure recovery)

[0183] After the modification (oxidation) treatment of the laminated membrane inside the processing container is completed, an inert gas is supplied as a purging gas into the processing chamber 201 through nozzles 249a and 249b, and exhaust is performed through exhaust port 231a. This purges the processing chamber 201, removing residual gases and reaction byproducts (post-purging). Then, the atmosphere inside the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0184] (Unloading the empty crystal boat)

[0185] Then, the sealing cover 219 is lowered using the crystal boat lift 115, opening the lower end of the manifold 209. The empty crystal boat 217 is then moved from the lower end of the manifold 209 to the outside of the reaction tube 203 (crystal boat unloading). After unloading, the gate 219s is moved, and the lower end opening of the manifold 209 is sealed by the gate 219s via the O-ring 220c (gate closing).

[0186] Thus, the modification treatment of the laminated membrane, which is composed of the first membrane and the second membrane, attached to the processing container is completed. This treatment can be performed once for each of the first membrane formation treatment and the second membrane formation treatment, or once for each of the first membrane formation treatment and the second membrane formation treatment two or more times.

[0187] (3) The effect of this method

[0188] According to this method, one or more of the effects shown below can be obtained.

[0189] (a) In step B, by performing a modification treatment that makes the composition of the second film in the laminated film attached to the processing container close to the composition of the first film, the film stress difference between the first and second films can be made smaller than the film stress difference between the first and second films before step B. As a result, the laminated film attached to the processing container becomes more difficult to peel off, and particle generation can be suppressed. As a result, the quality of the film formed on the wafer 200 can be improved, and the yield can be significantly increased. In addition, by suppressing film peeling, the frequency of cleaning processes can be reduced, and the downtime of the substrate processing apparatus can be shortened. By reducing the frequency of cleaning processes, it is possible to prevent components of cleaning gases detached from the inner wall of the processing container, etc., from mixing into the film formed on the wafer 200 during the subsequent first film formation process, thus preventing a deterioration in film quality.

[0190] (b) In step B, by supplying O-containing gas into the processing container for modification (oxidation) treatment, the membrane stress in both the first and second membranes can be reduced. Specifically, since the membrane stress of the second membrane, which has a higher membrane stress than the first membrane, can be reduced more significantly, the membrane stress difference between the first and second membranes can be reduced. Furthermore, in step B, by using a gas containing O contained in the first membrane (O-containing gas) for modification (oxidation) treatment, contamination of the gas supplied into the processing container can be prevented.

[0191] (c) By forming the second film with a thickness thinner than that of the first film, the first film can be used as an interlayer insulating film and the second film as a cover film.

[0192] (d) When step B (modification treatment) is performed once for each step A (performing the first film formation treatment and the second film formation treatment respectively), the membrane stress difference between the first film and the second film, i.e. the membrane stress difference between the first film and the second film in the laminated membrane attached to the treatment container, can be reliably reduced.

[0193] (e) When step B (modification treatment) is performed every two or more steps of step A (first film formation treatment and second film formation treatment), the difference in film stress between the first film and the second film in the laminated film attached to the treatment container can be reduced without substantially reducing throughput.

[0194] (f) By performing step A in a state where a wafer 200 is supported in a processing container and step B in a state where a wafer 200 is not supported in a processing container, the film stress difference between the first film and the second film in the laminated film attached to the wafer 217 and the processing container can be reduced without adversely affecting the laminated film formed on the wafer 200.

[0195] <Other ways of publishing this text>

[0196] The foregoing has provided a detailed explanation of the manner in which this disclosure is made. However, this disclosure is not limited to the manner described above and various changes may be made without departing from its essence.

[0197] The above description illustrates the formation of films containing semiconductor elements (Si) as the first and second films, but this disclosure is not limited to this. For example, this disclosure can also be applied when forming films containing metallic elements such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), tantalum (Ta), niobium (Nb), molybdenum (Mo), and tungsten (W) as the first and second films. In such cases, the same effects as those described above can be obtained.

[0198] The above description focuses on an example where C is used as the specified element to form a SiOCN film as the first film containing the specified element, but this disclosure is not limited to this. For example, this disclosure can also be applied when using B as the specified element and using a gas containing B, such as diborane (B₂H₆) gas or boron trichloride (BCl₃) gas, to form a silicon boron oxynitride film (SiBON film) as the first film. Furthermore, this disclosure can also be applied when using a gas containing both C and B as the specified elements to form a silicon boron oxycarbon nitride film (SiBOCN film) as the first film. In these cases, the same effect as in the above-described method can be obtained.

[0199] The above description focuses on an example of forming a stacked film consisting of a first film and a second film on the same wafer 200, but this disclosure is not limited to this. For example, this disclosure can also be applied when the first film and the second film are formed on different wafers 200. In such cases, the same effect as described above can be obtained.

[0200] The processes used in each process are preferably prepared individually according to the processing content and stored in advance in the storage device 121c via an electrical communication line and an external storage device 123. Furthermore, when starting each process, it is preferable that 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.

[0201] 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 be installed in the substrate processing apparatus via an electrical communication line and a recording medium containing the modified 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.

[0202] 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 this 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 this method; it can also be suitably applied when forming a film using a substrate processing apparatus with a cold-wall type furnace.

[0203] When using such a substrate processing apparatus, each process can be performed under the same processing steps and conditions as described above, and the same effect as described above can be obtained.

[0204] The above methods can be used in appropriate combinations. The processing steps and conditions can be the same as those in the methods described above.

[0205] Example

[0206] By performing the first process using the substrate processing apparatus described above, a laminated film consisting of SiOCN films and SiN films is formed on multiple wafers. Furthermore, the laminated film is formed on multiple wafers by performing the following second process, and an oxidation (modification) treatment is performed on the laminated film. In the SiOCN film, HCDS gas is used as the raw material gas, C3H6 gas is used as the gas containing a specified element, O2 gas is used as the O-containing gas, and NH3 gas is used as the N-containing gas. In the SiN film, the same as with the SiOCN film, HCDS gas, NH3 gas, and N-containing gas are used, respectively. In the oxidation (modification) treatment, O2 gas is used as the O-containing gas. Other processing conditions are general conditions within the range of processing conditions described above.

[0207] Processing step 1: (raw material gas → gas containing specified elements → gas containing O → gas containing N) × n → (raw material gas → gas containing N) × m

[0208] Processing step 2: (raw material gas → gas containing specified elements → gas containing O → gas containing N) × n → (raw material gas → gas containing N) × m → gas containing O

[0209] The SiN film in the laminated film formed by the first treatment is used as sample 1, and the SiOCN film is used as sample 2. The SiON film formed by oxidizing and modifying the SiN film in the laminated film by the second treatment is used as sample 3, and the SiOCN film formed by further absorbing O is used as sample 4.

[0210] The membrane stress in samples 1 through 4 was measured respectively. The results are shown in... Figure 9 The horizontal axis represents each sample. The vertical axis represents the membrane stress [MPa]. Positive stress on the vertical axis represents tensile stress, and negative stress represents compressive stress.

[0211] like Figure 9 As shown, the tensile stresses of samples 1-4 are approximately 800 MPa, 280 MPa, 250 MPa, and 230 MPa, respectively. This confirms that by performing oxidation treatment on the laminated film to modify the SiN film into a SiON film, the film stress is significantly reduced (from approximately 800 MPa to approximately 250 MPa). Furthermore, it is confirmed that by performing oxidation treatment on the laminated film, the SiOCN film further absorbs O, thus reducing the film stress (from approximately 280 MPa to approximately 230 MPa). Additionally, it is confirmed that by performing oxidation treatment on the laminated film to modify the SiN film into a SiON film, and making its composition similar to that of the SiOCN film, the stress difference between the SiON film (sample 3) and the SiOCN film (sample 4) is smaller than the stress difference between the SiN film (sample 1) and the SiOCN film (sample 2) before oxidation treatment.

[0212] In addition, XPS (X-ray photoelectron spectroscopy) was used to determine the composition ratio of the films of samples 1-4, i.e., the concentrations of Si, O, C, N, etc., in each film. It was confirmed that compared to sample 1 (SiN film), sample 3 (SiON film) had a higher O concentration, lower Si concentration, and lower N concentration. It was confirmed that compared to sample 2 (SiOCN film), sample 4 (SiOCN film) had a higher O concentration, lower Si and C concentrations, and no change in N concentration. It was confirmed that compared to sample 1 (SiN film), sample 2 (SiOCN film) had a higher O concentration, lower Si concentration, and lower N concentration. It was confirmed that compared to sample 3 (SiON film), sample 4 (SiOCN film) had a higher O concentration, almost equal Si concentration, higher C concentration, and lower N concentration.

[0213] Furthermore, it was confirmed that the difference in Si concentration between Sample 3 (SiON film) and Sample 4 (SiOCN film) was smaller compared to the difference in Si concentration between Sample 1 (SiN film) and Sample 2 (SiOCN film). The difference in O concentration between Sample 3 (SiON film) and Sample 4 (SiOCN film) was also confirmed to be smaller compared to the difference in O concentration between Sample 1 (SiN film) and Sample 2 (SiOCN film). The difference in C concentration between Sample 3 (SiON film) and Sample 4 (SiOCN film) was also confirmed to be smaller compared to the difference in C concentration between Sample 1 (SiN film) and Sample 2 (SiOCN film). The difference in N concentration between Sample 3 (SiON film) and Sample 4 (SiOCN film) was also confirmed to be smaller compared to the difference in N concentration between Sample 1 (SiN film) and Sample 2 (SiOCN film).

[0214] Furthermore, it was confirmed that in sample 1 (SiN film), the N concentration > Si concentration > O concentration, while in the modified sample 3 (SiON film), the Si concentration > N concentration > O concentration. Thus, the order of N and Si concentrations was reversed in samples 1 (SiN film) and 3 (SiON film). Additionally, it was confirmed that in sample 2 (SiOCN film), the Si concentration > O concentration > N concentration > C concentration, while in the modified sample 4 (SiOCN film), the Si concentration > O concentration > N concentration > C concentration remained unchanged.

[0215] As described above, it was confirmed that by performing oxidation treatment on either the SiN film or the SiOCN film in the laminated film, the O concentration increased. For example, it was confirmed that by performing oxidation treatment on the SiOCN film (sample 2) in the laminated film, the O concentration increased from 28 at% to 31 at%, and by performing oxidation treatment on the SiN film (sample 1) in the laminated film, the O concentration increased from 3 at% to 21 at%. Furthermore, it was confirmed that by performing oxidation treatment, the differences in the concentrations of Si, O, C, and N in each film after oxidation treatment decreased compared to each film before oxidation treatment. Thus, it was confirmed that, according to the oxidation treatment, the composition of sample 1 (SiN film) was modified to be close to the composition of sample 2 (SiOCN film).

Claims

1. A substrate processing method, which has the following characteristics: (a) A process of forming a laminated film composed of a first film and a second film on a substrate within a processing container, wherein, The first membrane contains nitrogen, oxygen, and specified elements; the second membrane contains nitrogen and has a different composition from the first membrane; and (b) A modification treatment step is performed in which oxygen-containing gas is supplied to the laminated membrane attached to the processing container in (a) to oxidize the second membrane constituting the laminated membrane attached to the processing container, such that the membrane stress difference between the first membrane and the second membrane constituting the laminated membrane attached to the processing container after (b) is smaller than the membrane stress difference between the first membrane and the second membrane constituting the laminated membrane attached to the processing container before (b). (c) Following (a), the process of removing the substrate from the processing container, Wherein, (b) is performed after (c) in a state where the substrate is not contained within the processing container.

2. The method as described in claim 1, wherein, The first film and the second film respectively contain at least one of a semiconductor element and a metallic element.

3. The method as described in claim 1, wherein, The specified element is at least one of carbon and boron.

4. The method of claim 1, wherein, The first film is a SiOCN film or a SiBON film.

5. The method of claim 4, wherein, The second film is a SiN film.

6. The method of claim 1, wherein, The oxygen concentration in the first membrane after (b) is higher than the oxygen concentration in the first membrane before (b).

7. The method of claim 1, wherein, In (a), the second film is formed with a thickness thinner than that of the first film.

8. The method of claim 1, wherein, Each time (a) is performed, (b) is performed.

9. The method of claim 1, wherein, Perform (b) after each of the two or more (a) sessions.

10. The method of claim 1, wherein, (a) is performed with the support member supporting the substrate housed in the processing container, and (b) is performed with the support member of the substrate that was not supported after (a) is housed in the processing container.

11. The method of claim 1, wherein, The second membrane prior to (b) is free of oxygen and any of the specified elements.

12. The method of claim 1, wherein, The difference in nitrogen concentration between the first membrane and the second membrane after (b) is smaller than the difference in nitrogen concentration between the first membrane and the second membrane before (b).

13. The method of claim 1, wherein, The difference in oxygen concentration between the first membrane and the second membrane after (b) is smaller than the difference in oxygen concentration between the first membrane and the second membrane before (b).

14. The method of claim 1, wherein, The concentration difference of the specified element in the first membrane and the second membrane after (b) is smaller than the concentration difference of the specified element in the first membrane and the second membrane before (b).

15. The method of claim 1, wherein, The second membrane also contains silicon. Before (b), the silicon concentration in the second membrane is lower than the nitrogen concentration, and after (b), the silicon concentration in the second membrane is higher than the nitrogen concentration.

16. The method of claim 1, wherein, In (a), the first film is formed by performing a predetermined number of cycles including the process of supplying the oxygen-containing gas to the substrate. In (b), the oxygen-containing gas is supplied to the laminated membrane attached to the processing container that does not contain the substrate for a longer time than in (a), the oxygen-containing gas is supplied to the substrate in each cycle.

17. A method for manufacturing a semiconductor device, comprising: (a) A process of forming a laminated film composed of a first film and a second film on a substrate within a processing container, wherein, The first membrane contains nitrogen, oxygen, and specified elements; the second membrane contains nitrogen and has a different composition from the first membrane; and (b) A modification treatment step is performed in which oxygen-containing gas is supplied to the laminated membrane attached to the processing container in (a) to oxidize the second membrane constituting the laminated membrane attached to the processing container, such that the membrane stress difference between the first membrane and the second membrane constituting the laminated membrane attached to the processing container after (b) is smaller than the membrane stress difference between the first membrane and the second membrane constituting the laminated membrane attached to the processing container before (b). (c) Following (a), the process of removing the substrate from the processing container, Wherein, (b) is performed after (c) in a state where the substrate is not contained within the processing container.

18. A computer-readable recording medium containing a program that enables a substrate processing apparatus to perform the following steps using a computer: (a) The step of forming a laminated film composed of a first film and a second film on a substrate within a processing container of a substrate processing apparatus, wherein, The first membrane contains nitrogen, oxygen, and specified elements, and the second membrane contains nitrogen but has a different composition from the first membrane. (b) A modification treatment step is performed in which oxygen-containing gas is supplied to the laminated membrane attached to the processing container in (a) to oxidize the second membrane constituting the laminated membrane attached to the processing container, such that the membrane stress difference between the first membrane and the second membrane constituting the laminated membrane attached to the processing container after (b) is smaller than the membrane stress difference between the first membrane and the second membrane constituting the laminated membrane attached to the processing container before (b). (c) Following (a), the step of removing the substrate from the processing container, Wherein, (b) is performed after (c) in a state where the substrate is not contained within the processing container.

19. A substrate processing apparatus, comprising: A processing container for housing substrates; A processing gas supply system that supplies nitrogen-containing gas, oxygen-containing gas, and gas containing specified elements into the processing container; and The control unit is configured to control the processing gas supply system in such a manner as to perform the following processing within the processing container: (a) a processing of forming a laminated film composed of a first film and a second film on a substrate within the processing container, wherein, The first film contains nitrogen, oxygen, and a specified element, and the second film contains nitrogen and has a different composition from the first film. (b) A modification treatment is performed in which oxygen-containing gas is supplied to the laminated film attached to the processing container in (a) to oxidize the second film constituting the laminated film attached to the processing container, such that the film stress difference between the first film and the second film constituting the laminated film attached to the processing container after (b) is smaller than the film stress difference between the first film and the second film constituting the laminated film attached to the processing container before (b). (c) After (a), the substrate is removed from the processing container. Wherein, (b) is performed after (c) in a state where the substrate is not contained within the processing container.

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