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

Abstract

The present invention provides the following technology, which has: (a) a process of forming a film containing a first element on a substrate by supplying a gas containing the first element to the substrate in an atmosphere free of oxygen; and (b) a process of forming an oxidized film by oxidizing the film containing the first element by supplying a gas containing oxygen to the substrate, in which a different substrate temperature is selected depending on the thickness of the film containing the first element.

Description

Technical Field

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

[0002] As a step in the manufacturing process of semiconductor devices, the following film formation process is sometimes performed: forming a film on a substrate and oxidizing the film to form an oxide 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. 2014-154652

[0006] Patent Document 2: WO2018 / 055674 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The purpose of this disclosure is to improve the effect of inhibiting substrate oxidation when an oxide film forms on the substrate.

[0009] Methods for solving problems

[0010] According to one aspect of this disclosure, the following technology is provided, which has the following characteristics:

[0011] (a) A process of forming a film containing the first element on the substrate by supplying a gas containing the first element to the substrate in a processing chamber under an oxygen-free atmosphere; and

[0012] (b) The process of forming an oxide film by oxidizing the aforementioned film containing the first element by supplying oxygen-containing gas to the aforementioned substrate.

[0013] In (b), the temperature of the aforementioned substrate is selected according to the thickness of the aforementioned film containing the first element.

[0014] The effects of the invention

[0015] According to this disclosure, it is possible to improve the effect of suppressing substrate oxidation when an oxide film forms on the substrate. Attached Figure Description

[0016] [ Figure 1 ] Figure 1 This is a schematic diagram of a vertical processing furnace suitable for use in one embodiment of the present disclosure, and is a longitudinal sectional view showing part 202 of the processing furnace.

[0017] [ Figure 2] Figure 2 This is a schematic diagram of a vertical processing furnace suitable for use in one embodiment of the present disclosure, and is based on... Figure 1 The AA-line sectional view shows part of the processing furnace 202.

[0018] [ Figure 3 ] 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 a block diagram showing the control system of the controller 121.

[0019] [ Figure 4 ] Figure 4 A diagram illustrating an example of the timing of gas supply and processing temperature in a film-forming process according to one method of this disclosure.

[0020] [ Figure 5 ] Figure 5 (a) is a partial enlarged cross-sectional view of the surface of wafer 200 before film deposition. Figure 5 (b) is a partial enlarged cross-sectional view of the surface of wafer 200 after a nitride film containing the first element has been formed on wafer 200. Figure 5 (c) is a partially enlarged cross-sectional view of the surface of wafer 200 after the nitride film formed on wafer 200 is oxidized to form an oxide film.

[0021] [ Figure 6 ] Figure 6 A diagram illustrating an example of the timing of gas supply and processing temperature in another form of film formation process according to this disclosure.

[0022] [ Figure 7 ] Figure 7 (a) is a partial enlarged cross-sectional view of the surface of wafer 200 before film deposition. Figure 7 (b) is a partial enlarged cross-sectional view of the surface of wafer 200 after a film containing the first element has been formed on wafer 200. Figure 7 (c) is a partially enlarged cross-sectional view of the surface of wafer 200 after the film containing the first element formed on wafer 200 is oxidized to form an oxide film.

[0023] [ Figure 8 ] Figure 8 A graph showing the relationship between the supply time of O-containing gas and H-containing gas in the examples and the amount of oxidation of the nitride film at a specified gas supply time, according to the processing temperature. Detailed Implementation

[0024] <One way of publishing this text>

[0025] The following is mainly based on Figures 1-4 , Figure 5 (a)~ Figure 5 (c) This disclosure is described in one manner. It should be noted that the accompanying drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings are not necessarily consistent with reality. Furthermore, the dimensional relationships and ratios of the elements in multiple drawings are not necessarily consistent with each other.

[0026] (1) Composition of substrate processing device

[0027] 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.

[0028] 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), forming 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), forming a cylindrical shape that is open at both the top and bottom. 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 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 part of the cylindrical processing container. The processing chamber 201 is configured to accommodate a wafer 200 as a substrate. Processing of the wafer 200 is performed within the processing chamber 201.

[0029] Nozzles 249a and 249b, serving as first and second supply units, are respectively provided inside the processing chamber 201, penetrating the side wall of the manifold 209. Nozzles 249a and 249b are also referred to as the first and second nozzles, respectively. Nozzles 249a and 249b are made of heat-resistant materials such as quartz or SiC. Gas supply pipes 232a and 232b are connected to nozzles 249a and 249b, respectively.

[0030] 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 gas flow. Gas supply pipes 232c and 232e are connected to the downstream side of gas supply pipe 232a, relative to valve 243a. Gas supply pipes 232d and 232f are connected to the downstream side of gas supply pipe 232b, relative to valve 243b. 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 gas flow. Gas supply pipes 232a to 232f are constructed of a metallic material such as SUS.

[0031] like Figure 2 As shown, nozzles 249a and 249b are respectively arranged in a ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200 in a way that extends upward from the lower part of the inner wall of the reaction tube 203 toward the arrangement direction of the wafer 200. That is, nozzles 249a and 249b are respectively arranged in a region that horizontally surrounds the wafer arrangement region on the side of the wafer arrangement region for arranging the wafer 200. Gas supply holes 250a and 250b are respectively provided on the side of nozzles 249a and 249b for supplying gas. Gas supply holes 250a and 250b are each open toward the center of the reaction tube 203, and can supply gas toward the wafer 200. Multiple gas supply holes 250a and 250b are provided from the lower part to the upper part of the reaction tube 203.

[0032] Gas containing the first element, i.e. gas containing the first element, is supplied into the processing chamber 201 from the gas supply pipe 232a via MFC 241a, valve 243a, and nozzle 249a.

[0033] Nitrogen (N) gas is supplied as nitriding gas from gas supply pipe 232b, via MFC 241b, valve 243b, and nozzle 249b into processing chamber 201.

[0034] Hydrogen (H) gas is supplied into the processing chamber 201 from the gas supply pipe 232c via MFC 241c, valve 243c, gas supply pipe 232a, and nozzle 249a. The H gas alone cannot achieve oxidation, but it functions by reacting with oxygen (O) gas under specific conditions to generate atomic oxygen (O) and other oxidizing agents, thereby improving the efficiency of the oxidation process.

[0035] O-containing gas is supplied to the processing chamber 201 from the gas supply pipe 232d, via MFC 241d, valve 243d, gas supply pipe 232b, and nozzle 249b.

[0036] Inactive gas is supplied to the treatment chamber 201 from 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.

[0037] The system comprises a silane-based gas supply system, mainly consisting of gas supply pipe 232a, MFC 241a, and valve 243a, forming the first gas supply system (first gas supply section). The system also comprises a nitrogen-containing gas supply system, mainly consisting of gas supply pipe 232b, MFC 241b, and valve 243b. The system further comprises a nitrogen-containing gas supply system, mainly consisting of gas supply pipe 232d, MFC 241d, and valve 243d, forming the second gas supply system (second gas supply section). The system also comprises a hydrogen-containing gas supply system, mainly consisting of gas supply pipes 232e and 232f, MFC 241e and 241f, and valves 243e and 243f, forming the inactive gas supply system.

[0038] Any one or all of the aforementioned supply systems can also be configured as an integrated supply system 248, which integrates valves 243a-243f, MFCs 241a-241f, etc. The integrated supply system 248 is configured such that it is connected to each of the gas supply pipes 232a-232f, and the supply of various gases to the gas supply pipes 232a-232f, i.e., the opening and closing of valves 243a-243f, and the flow regulation by MFCs 241a-241f, are controlled by the controller 121 described later. The integrated supply system 248 is configured as an integrated unit, either as a single unit or as separate units, and is configured such that it can be disassembled and assembled relative to the gas supply pipes 232a-232f, etc., and that the integrated supply system 248 can be maintained, replaced, or added to in units.

[0039] An exhaust port 231a for venting the atmosphere inside the processing chamber 201 is provided below the side wall of the reaction tube 203. 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 venting 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 (Auto Pressure Controller) valve 244, which is a pressure regulator (pressure regulating unit). The APC valve 244 is configured such that by opening and closing the valve while the vacuum pump 246 is operating, vacuum venting and vacuum venting stop can be performed inside 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. Including vacuum pump 246 in the exhaust system could be considered.

[0040] 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 conveying device (conveying mechanism), which moves the wafer 200 into the processing chamber 201 and out of the processing chamber 201 by raising and lowering the sealing cover 219.

[0041] Below the manifold 209 is a gate 219s serving as a furnace opening cover. This gate 219s can airtightly seal the lower opening of the manifold 209 after the sealing cover 219 has been lowered and the crystal boat 217 has been removed from the processing chamber 201. The gate 219s is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220c, serving as a sealing component, is provided on the upper surface of the gate 219s, abutting 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.

[0042] The support boat 217, serving as the support substrate, is configured to hold multiple wafers 200 (e.g., 25 to 200) arranged horizontally with their centers aligned in the vertical direction and supported in a multi-layered manner, i.e., spaced apart. The crystal boat 217 is made of a heat-resistant material such as quartz or SiC. A heat-insulating plate 218, also made of a heat-resistant material such as quartz or SiC, is supported in multiple layers at the bottom of the crystal boat 217.

[0043] A temperature sensor 263, serving as a temperature detector, is installed inside the reaction tube 203. The energizing of the heater 207 is adjusted based on the temperature information detected by the temperature sensor 263, thereby achieving the desired temperature distribution within the processing chamber 201. The temperature sensor 263 is disposed along the inner wall of the reaction tube 203.

[0044] like Figure 3 As shown, the controller 121, which serves 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.

[0045] The storage device 121c is composed of, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. Within the storage device 121c, a control program that controls the operation of the substrate processing apparatus, and a process flow that describes the processing steps and conditions described later are stored in a readable manner. The process flow is a combination of methods that enable the controller 121 to execute each step of the processing described later and obtain a predetermined result, and functions as a program. Hereinafter, the process flow, control program, etc., will also be referred to as a program. Furthermore, the process flow will be referred to as a process. In this specification, the term "program" is used in cases where only the process flow is included, cases where only the control program is included, or cases where both are included. RAM 121b is configured as a memory area (working area) that temporarily holds the program, data, etc., read by the CPU 121a.

[0046] 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.

[0047] CPU 121a is configured to read and execute control programs from storage device 121c, and to read processes from storage device 121c based on inputs of operation commands from input / output device 122. CPU 121a is configured to control the following actions according to the content of the read processes: flow regulation of various gases by MFCs 241a to 241h, opening and closing of valves 243a to 243h, opening and closing of APC valve 244 and pressure regulation based on pressure sensor 245 using APC valve 244, 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.

[0048] 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 computer-readable recording medium. Hereinafter, they will also be referred to collectively as recording media. In this specification, the term "recording medium" includes 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.

[0049] (2) Substrate processing process

[0050] Main use Figure 4 , Figure 5 (a)~ Figure 5 Example (c) illustrates the following film formation process sequence: Using the substrate processing apparatus described above, as a step in the manufacturing process of a semiconductor device, an oxide film of a specified thickness is formed on a wafer 200 serving as a substrate. It should be noted that in this method, a wafer 200 without an oxide film on its surface is used. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0051] In the film-forming process of this method, the following steps are performed:

[0052] Step a: forming a film containing the first element on the wafer 200 by supplying a gas containing the first element to the wafer 200 in a processing chamber under an oxygen-free atmosphere; and

[0053] Step b involves supplying oxygen-containing gas to wafer 200 to oxidize the membrane containing the first element, thereby forming an oxide film.

[0054] In step b, the temperature of the wafer 200 is selected according to the thickness of the film containing the first element.

[0055] As an example, in the film-forming process sequence of this method,

[0056] In step a, the steps of supplying the gas containing the first element to the wafer 200 and supplying the N-containing gas as the nitriding gas to the wafer 200 are performed non-simultaneously for a predetermined number of times (n times, where n is an integer greater than or equal to 1), thereby forming a nitriding film containing the first element (hereinafter, sometimes simply referred to as a nitriding film).

[0057] Furthermore, as an example, in the film-forming process sequence of this method,

[0058] In step b, O-containing gas and H-containing gas are simultaneously supplied to the wafer 200 in the processing chamber 201 which is under reduced pressure (below atmospheric pressure) to oxidize the nitride film containing the first element, thereby forming an oxide film containing the first element (hereinafter, sometimes simply referred to as an oxide film).

[0059] It should be noted that the surface of the wafer 200 subjected to the film-forming process in this method is composed of a substantially unoxidized substrate (oxygen-free substrate). That is, an oxygen-free layer or film is formed on the surface of the wafer 200 as a substrate. In this method, examples of oxygen-free substrates include elemental films of silicon (Si), aluminum (Al), hafnium (Hf), zirconium (Zr), titanium (Ti), or nitride films or carbide films containing these elements, but it is not limited to these as long as it has an oxygen-free composition.

[0060] For convenience, the above-described film-forming process sequence is sometimes shown as follows in this specification. The same wording is also used in the descriptions of other methods, etc., below.

[0061] (Gas containing element 1 → Gas containing N) × n → (Gas containing O + Gas containing H)

[0062] In this specification, the term "wafer" is used to refer to the wafer itself, or to 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, or to the surface of a specified layer, etc., formed on the wafer. The phrase "forming a specified layer on the wafer" includes forming the specified layer directly on the surface of the wafer itself, or 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."

[0063] (Wafer filling and crystal boat loading)

[0064] During the loading of multiple wafers 200 into the wafer boat 217 (wafer filling), the gate 219s is moved by the gate opening and closing mechanism 115s, opening the lower end opening of the manifold 209 (gate opening). Then, as... Figure 1 As shown, a crystal boat 217 supporting multiple wafers 200 is lifted by a crystal boat elevator 115 and moved into the processing chamber 201 (crystal boat loading). In this state, the sealing cap 219 seals the lower end of the manifold 209 by means of an O-ring 220b.

[0065] (Pressure and temperature regulation)

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

[0067] (Formation of a nitride film containing element 1)

[0068] Then, perform steps 1 and 2 in sequence.

[0069] [Step 1]

[0070] In step 1, a gas containing the first element is supplied to the wafer 200 in the processing chamber 201.

[0071] Specifically, valve 243a is opened, allowing gas containing element 1 to flow into gas supply pipe 232a. The flow rate of the gas containing element 1 is regulated by MFC 241a, and it is supplied to processing chamber 201 via nozzle 249a and exhausted from exhaust port 231a. At this time, gas containing element 1 is supplied to wafer 200 (gas containing element 1 supply). Then, valves 243e and 243f can be opened, supplying inactive gases to processing chamber 201 via nozzles 249a and 249b respectively. Thus, this step does not supply oxygen-containing gas to processing chamber 201, but rather processes wafer 200 in an oxygen-free atmosphere.

[0072] As a processing condition for this step, an example can be given:

[0073] Gas supply flow rate containing element 1: 1–2000 sccm, preferably 10–1000 sccm

[0074] Inactive gas supply flow rate (per gas supply tube): 100–2000 slm

[0075] Gas supply time: 1–120 seconds, preferably 1–60 seconds

[0076] Processing temperature (temperature of wafer 200): 350–800℃, preferably 450–800℃

[0077] Processing pressure (pressure inside processing chamber 201): 1-13300 Pa, preferably 10-1330 Pa.

[0078] It should be noted that the numerical ranges expressed in this specification, such as "10~1330Pa", refer to the inclusion of both the lower and upper limits within that range. Therefore, for example, "10~1330Pa" means "above 10Pa and below 1330Pa". The same applies to other numerical ranges.

[0079] When a chlorosilane-based gas, such as the Si-containing gas described later, is used as the gas containing the first element, by supplying the chlorosilane-based gas to the wafer 200 under the above conditions, a Si-containing layer containing chlorine (Cl) of a predetermined thickness is formed as the first layer on the outermost surface of the wafer 200, which serves as the substrate. The Si-containing layer containing Cl is formed by: physical adsorption or chemisorption of molecules of the chlorosilane-based gas onto the outermost surface of the wafer 200; chemisorption of molecules of substances obtained from the partial decomposition of the chlorosilane-based gas onto the outermost surface of the wafer 200; or deposition of Si on the outermost surface of the wafer 200 due to the thermal decomposition of the chlorosilane-based gas. The Si-containing layer containing Cl can be an adsorption layer (physical adsorption layer, chemisorption layer) of molecules of the chlorosilane-based gas and molecules of substances obtained from the partial decomposition of the chlorosilane-based gas, or it can be a deposited layer of Si containing Cl. When the aforementioned chemisorption layer and the aforementioned stacked layer are formed on the outermost surface of the wafer 200, Si contained in the chlorosilane gas is adsorbed on the outermost surface of the wafer 200. In this specification, the Si-containing layer containing Cl will also be simply referred to as the Si-containing layer.

[0080] After the Si-containing layer is formed, valve 243a is closed to stop the supply of gas containing the first element to the processing chamber 201. Then, a vacuum is applied to the processing chamber 201 to remove any remaining gases (purge). At this time, with valves 243e and 243f open, an inactive gas is supplied to the processing chamber 201. This inactive gas acts as a purging gas.

[0081] As a gas containing element 1, for example, a silane-based gas containing Si as element 1 can be used. As a silane-based gas, for example, a gas containing Si and a halogen, i.e., a halosilane gas, can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As a halosilane gas, for example, a chlorosilane gas containing Si and Cl can be used.

[0082] More specifically, as gases containing Si as the first element, for example, monochlorosilane (SiH3Cl, abbreviated as MCS), dichlorosilane (SiH2Cl2, abbreviated as DCS), trichlorosilane (SiHCl3, abbreviated as TCS), tetrachlorosilane (SiCl4, abbreviated as STC), hexachlorosilane (Si2Cl6, abbreviated as HCDS), and octachloropropane (Si3Cl8, abbreviated as OCTS) gases, etc., can be used. Alternatively, as gases containing Si as the first element, for example, fluorosilane gases such as tetrafluorosilane (SiF4) and difluorosilane (SiH2F2), bromosilane gases such as tetrabromosilane (SiBr4) and dibromosilane (SiH2Br2), tetraiodosilane (SiI4) and diiodosilane (SiH2I2) gases, etc., can also be used. Alternatively, as gases containing the first element, for example, aminosilane gases containing Si as the first element, such as tetra(dimethylamino)silane (Si[N(CH3)2]4, abbreviated as 4DMAS), tri(dimethylamino)silane (Si[N(CH3)2]3H, abbreviated as 3DMAS), bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviated as BDEAS), and bis(tert-butylamino)silane (SiH2[NH(C4H9)]2, abbreviated as BTBAS), can also be used. One or more of these gases can be used as the first element.

[0083] As an inert gas, nitrogen (N2) can be used, as well as rare gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe). More than one of these gases can be used as an inert gas. This also applies to the steps described later.

[0084] [Step 2]

[0085] After step 1 is completed, N-containing gas is supplied to the wafer 200 in the processing chamber 201, that is, the Si-containing layer (containing the first element) formed on the wafer 200 as the first layer.

[0086] Specifically, valve 243b is opened, allowing nitrogen-containing gas to flow into the gas supply pipe 232b. The flow rate of the nitrogen-containing gas is regulated by MFC 241b, 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 (nitrogen-containing gas supply). Then, valves 243e and 243f can be opened, supplying inactive gas into the processing chamber 201 via nozzles 249a and 249b. Thus, oxygen-containing gas is not supplied to the processing chamber 201 in this step; instead, the wafer 200 is processed in an oxygen-free atmosphere.

[0087] As a processing condition for this step, an example can be given:

[0088] Nitrogen gas supply flow rate: 100–10000 sccm

[0089] Nitrogen gas supply time: 1–120 seconds

[0090] Processing pressure (pressure inside processing chamber 201): 100-13300 Pa, preferably 500-3000 Pa.

[0091] Set the other processing conditions to be the same as those in step 1.

[0092] By supplying a nitrogen-containing gas as a nitriding gas to the wafer 200 under the above conditions, at least a portion of the Si-containing layer formed on the wafer 200 is nitrided (modified). As a result, a silicon nitride layer (SiN layer) is formed as a second layer on the outermost surface of the wafer 200, which serves as a substrate. This layer contains the first element, namely, Si and N. During the formation of the SiN 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 using the nitrogen-containing gas, and are 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 formed in step 1.

[0093] After the SiN layer, which serves as the second layer, is formed, valve 243b is closed to stop the supply of N-containing gas to the processing chamber 201. Then, the gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 through the same processing steps as in step 1 (purging).

[0094] Regarding the N-containing gas used as the nitriding gas (nitriding agent), for example, a gas containing both N and H can be used. The gas containing both N and H preferably has NH bonds. Examples of nitriding gases with NH bonds include ammonia (NH3), diazepine (N2H2), hydrazine (N2H4), and N3H8, etc., which are hydrogen nitriding gases. One or more of these can be used as the nitriding gas.

[0095] Furthermore, regarding the N-containing gas used as a nitriding gas, gases containing nitrogen (N), carbon (C), and hydrogen (H) can also be used, for example. As gases containing N, C, and H, amine-based gases and organic hydrazine-based gases can be used, for example. Gases containing N, C, and H are also N-containing gases, C-containing gases, H-containing gases, and gases containing both N and C.

[0096] More specifically, as gases containing N, C, and H, for example, ethylamine gases such as monoethylamine (C2H5NH2, abbreviated as MEA), diethylamine ((C2H5)2NH, abbreviated as DEA), and triethylamine ((C2H5)3N, abbreviated as TEA) can be used; methylamine gases such as monomethylamine (CH3NH2, abbreviated as MMA), dimethylamine ((CH3)2NH, abbreviated as DMA), and trimethylamine ((CH3)3N, abbreviated as TMA) can be used; and organohydrazine gases such as monomethylhydrazine ((CH3)HN2H2, abbreviated as MMH), dimethylhydrazine ((CH3)2N2H2, abbreviated as DMH), and trimethylhydrazine ((CH3)2N2(CH3)H, abbreviated as TMH) can be used. One or more of these gases can be used as gases containing N, C, and H.

[0097] [Perform the prescribed number of cycles]

[0098] By performing steps 1 and 2 of the above process asynchronously a predetermined number of times (n times, where n is an integer greater than or equal to 1), thus achieving... Figure 5 As shown in (b), a SiN film containing a first element, of a predetermined thickness, can be formed on the surface of wafer 200 as a substrate. The above-described cycle is preferably repeated multiple times. That is, it is preferable to make the thickness of the SiN layer formed in each cycle thinner than the desired film thickness, until the thickness of the SiN film formed by stacking SiN layers reaches the desired thickness, and the above cycle is repeated multiple times. It should be noted that the SiN film containing a first element formed in step a is oxidized in step b, which is described later, thereby expanding at a predetermined ratio and transforming into an oxide film containing a first element, SiO. In step a, it is preferable to take into account this, i.e., the expansion ratio of the SiN film, and perform an inverse operation based on the target film thickness of the SiO film to be formed in step b to determine the film thickness of the SiN film.

[0099] (Pressure and temperature regulation)

[0100] After the process of forming a SiN film of the desired thickness on the wafer 200 is completed, the APC valve 244 is adjusted to a predetermined pressure below atmospheric pressure (pressure regulation) so that the pressure inside the processing chamber 201 is lower than atmospheric pressure. In addition, the output power of the heater 207 is adjusted to a predetermined temperature so that the temperature of the wafer 200 inside the processing chamber 201 is reached (temperature regulation).

[0101] (Formation of an oxide film containing element 1)

[0102] Then, an O-containing gas and a H-containing gas, which are oxidizing gases, are supplied to the wafer 200 in the processing chamber 201, that is, the SiN film formed on the wafer 200 as a nitride film containing the first element.

[0103] Specifically, valve 243d is opened, allowing O-containing gas to flow into gas supply pipe 232d. The flow rate of the O-containing gas flowing into gas supply pipe 232d is regulated by MFC 241d and supplied to processing chamber 201 via nozzle 249b. Simultaneously, valve 243c is opened, allowing H-containing gas to flow into gas supply pipe 232c. The flow rate of the H-containing gas flowing into gas supply pipe 232c is regulated by MFC 241c and supplied to processing chamber 201 via nozzle 249a. The O-containing gas and H-containing gas mix and react within processing chamber 201, and are then exhausted from exhaust port 231a. At this time, oxygen-containing, moisture-free (H2O) oxides, such as atomic oxygen produced by the reaction of O-containing gas and H-containing gas, are supplied to wafer 200 (O-containing gas + H-containing gas supply). At this time, valves 243e and 243f can be opened, supplying inactive gases to processing chamber 201 via nozzles 249a and 249b.

[0104] As a processing condition for this step, an example can be given:

[0105] O-containing gas supply flow rate: 1000~30000sccm

[0106] H-containing gas supply flow rate: 1000~10000sccm

[0107] Gas supply time: 1–1000 minutes, preferably 1–300 minutes

[0108] Processing temperature (temperature of wafer 200): 300°C or higher and less than 800°C, preferably 300°C or higher and less than 600°C.

[0109] Processing pressure (pressure inside processing chamber 201): 1 Pa or more and lower than atmospheric pressure, preferably 1 to 1000 Pa.

[0110] Set the other processing conditions to be the same as those in step 1.

[0111] By supplying O-containing gas and H-containing gas to the wafer 200 under the above conditions, the strong oxidizing power of oxidants such as atomic oxygen can be used to oxidize the SiN film formed on the wafer 200, introducing O into the film. Furthermore, N contained in the SiN film can be removed from the film. Thus, as... Figure 5 As shown in (c), it is possible to transform the SiN film formed on the wafer 200 as a nitride film containing the first element into a SiO film as an oxide film containing the first element.

[0112] Furthermore, when the SiN film is oxidized to form a SiO film under the above conditions, O is introduced into the SiN film during the oxidation process, thereby causing it to expand at a predetermined ratio (expansion ratio). Therefore, the SiO film formed by performing step b becomes a film with a greater thickness than the SiN film before oxidation (the SiN film formed by performing step a). For example, if the thickness of the SiN film formed by performing step a is set to... In this case, the thickness of the SiO film formed by performing step b under the above processing conditions becomes the thickness multiplied by its expansion ratio (approximately 1.6), i.e. The thickness on the left and right sides.

[0113] In this step, the processing temperature (temperature of wafer 200) is selected based on the thickness of the SiN film formed in step a.

[0114] For example, in this step, the processing temperature is selected based on the thickness of the SiN film, at a temperature that ensures the SiN film is oxidized throughout its thickness direction. By selecting such a temperature in this step, the SiN film formed in step a can be oxidized throughout its thickness direction and transformed into a SiO film.

[0115] For example, in this step, the processing temperature is selected based on the thickness of the SiN film to oxidize the SiN film throughout its thickness direction without oxidizing the interface between the wafer 200 and the SiN film (i.e., the surface of the wafer 200, which serves as the substrate for forming the SiN film). By selecting such a temperature in this step, the SiN film formed in step a can be oxidized throughout its thickness direction to transform into a SiO film, while suppressing oxidation of the surface of the wafer 200, which serves as its substrate.

[0116] For example, in this step, the processing temperature is selected based on the thickness of the SiN film, at a time point when the oxidation reaction saturates the SiN film throughout its thickness direction. If such a temperature is selected in this step and this step is continued until the oxidation reaction of the SiN film is saturated, the SiN film formed in step a can be oxidized throughout its thickness direction, transforming it into a SiO film. Furthermore, by selecting such a temperature in this step, the oxidation reaction can be saturated at the time point when the SiN film is oxidized throughout its thickness direction, and oxidation of the wafer 200 surface can be suppressed even if the processing time is exceeded thereafter. In other words, by selecting such a temperature in this step, oxidation of the wafer 200 surface can be suppressed, and a process that oxidizes the entire SiN film can be easily achieved without strict management of the processing time.

[0117] It should be noted that the "saturation of the oxidation reaction" mentioned here refers to the following state: the rate of increase in oxide film thickness per unit time gradually decreases, becoming... or close to In this specification, "oxidation reaction saturation" is not limited to the rate of increase in oxide film thickness per unit time. Regarding the situation where the oxide film thickness increases per unit time... The following, preferred The following situation is also considered to be included in "oxidation reaction saturation". The rate of increase essentially converges to... Sometimes it takes a very long time, but from a practical point of view, if the time point at which the SiN film is oxidized throughout its thickness direction is chosen, the rate of increase becomes... The following processing temperature achieves the aforementioned effects (i.e., it suppresses oxidation on the surface of wafer 200 and easily achieves overall oxidation of the SiN film without strict control over the processing time). Furthermore, if this rate of increase is chosen to be... The following processing temperatures can suppress oxidation on the surface of wafer 200 and perform the process of oxidizing the SiN film more accurately (with high controllability).

[0118] It should be noted that when the thickness of the SiN film formed by step a is set as... In this case, the selectable processing temperature for this step, as described above, is, for example, above 300°C and below 800°C. This is especially true when the thickness of the SiN film is set to... In this case, the processing temperature that can be selected in this step, as described above, is preferably 300°C or higher and less than 600°C.

[0119] When the processing temperature is below 300℃, it is difficult to generate oxide species suitable for oxidizing the SiN film. By raising the processing temperature to above 300℃, sufficient oxide species can be generated for oxidizing the SiN film, resulting in overall oxidation of the SiN film throughout its thickness direction.

[0120] When the processing temperature is above 800°C, the processing time required for the oxidation reaction to reach saturation increases significantly, making it difficult to saturate the oxidation reaction within a practical processing time range. By lowering the processing temperature below 800°C, the oxidation reaction can be saturated within a practical processing time range. For example, by lowering the processing temperature below 800°C, the rate of increase in oxide film thickness can be saturated in a shorter time. The following describes the time point at which the SiN film can be oxidized overall. The oxidation reaction of the thin SiN film can be reliably saturated. Furthermore, by keeping the processing temperature below 600°C, the oxidation reaction can be saturated more precisely within a practical processing time range. For example, by keeping the processing temperature below 600°C, the rate of increase in oxide film thickness can be saturated to [a certain value] in a shorter time. The following describes the time point at which the SiN film can be oxidized overall. The oxidation reaction of the thinner SiN film on the left and right sides is reliably saturated.

[0121] After the SiN film is converted into a SiO film, valves 243d and 243c are closed to stop the supply of O-containing gas and H-containing gas to the processing chamber 201.

[0122] As gases containing oxygen (O), oxygen (O2), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), ozone (O3), H2O, carbon monoxide (CO), and carbon dioxide (CO2) can be used. As gases containing hydrogen (H), hydrogen (H2) and deuterium (D2) can be used.

[0123] (Post-purging and atmospheric pressure recovery)

[0124] After the process of forming a SiO film of the desired thickness on the wafer 200 is completed, inert gases are supplied as purge gases into the processing chamber 201 from nozzles 249a and 249b, and exhaust gases are discharged from the exhaust port 231a. This purges the processing chamber 201, removing residual gases and reaction byproducts (post-purge). Then, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0125] (Crystal boat unloading and chip removal)

[0126] Then, the sealing cover 219 is lowered by the crystal boat lift 115, opening the lower end of the manifold 209. The processed wafer 200, supported by the crystal boat 217, is then moved from the lower end of the manifold 209 to the outside of the reaction tube 203 (crystal boat unloading). After unloading, the gate 219s is moved, sealing the lower opening of the manifold 209 by means of an O-ring 220c (gate closing). The processed wafer 200 is then removed from the crystal boat 217 after being moved to the outside of the reaction tube 203 (wafer removal).

[0127] (3) Effects of this method

[0128] According to this method, one or more of the effects shown below can be obtained.

[0129] (a) In step b, the processing temperature is selected based on the thickness of the nitride film containing the first element (nitride film). Thus, by using the processing temperature, which is easier to control among various processing conditions, as the control parameter in step b, the oxidation rate of the nitride film formed on the wafer 200 can be easily controlled.

[0130] (b) In step b, the processing temperature is selected based on the thickness of the nitride film, at a temperature that ensures the entire nitride film is oxidized throughout its thickness direction. By selecting such a temperature, the entire nitride film can be reliably oxidized throughout its thickness direction.

[0131] (c) In step b, the processing temperature is selected based on the thickness of the nitride film to oxidize the nitride film throughout its thickness direction without oxidizing the surface of the wafer 200. By selecting such a temperature, the nitride film can be reliably oxidized throughout its thickness direction, and oxidation of the wafer 200 surface can be reliably suppressed.

[0132] (d) In step b, the processing temperature is selected based on the thickness of the nitride film, at a time point when the oxidation reaction saturates to the point where the nitride film is oxidized throughout its thickness direction. Because such a temperature is selected, if step b is continued until at least the oxidation reaction of the nitride film is saturated, the nitride film formed in step a can be reliably oxidized throughout its thickness direction. Furthermore, even if the processing time exceeds the point where the nitride film is oxidized throughout its thickness direction, oxidation of the wafer 200 surface can be reliably suppressed. In other words, by selecting such a temperature in step b, oxidation of the wafer 200 surface can be suppressed, and a process that oxidizes the entire nitride film can be easily achieved without strict management of the processing time.

[0133] (e) In step a, taking into account the expansion ratio of the nitride film, the thickness of the SiN film is determined by performing an inverse operation based on the target film thickness of the oxide film containing the first element (oxide film) to be formed in step b. Thus, an oxide film of the desired thickness can be formed on the wafer 200.

[0134] (f) Since step a is performed in an oxygen-free atmosphere, oxidation of the wafer 200 surface can be suppressed. Furthermore, by selecting a temperature in step b that causes overall oxidation of the nitride film throughout its thickness direction without oxidizing the surface of the wafer 200 (e.g., selecting a temperature at which the oxidation reaction saturates at the point in time when the nitride film is oxidized throughout its thickness direction), reliable overall oxidation of the nitride film throughout its thickness direction can be achieved, and oxidation of the wafer 200 surface can be suppressed. Thus, this disclosure is significantly superior to the prior art in that it can prevent oxidation of the wafer 200 surface and form an extremely thin oxide film on the wafer 200. It should be noted that, according to conventional methods that alternately or simultaneously supply silane-based gases and O-containing gases to the wafer 200, it is difficult to form, for example, on the wafer 200 while preventing oxidation of the wafer 200 surface. The SiO film is extremely thin as an oxide film.

[0135] (g) By alternately supplying a gas containing the first element and a nitrogen-containing gas to the wafer 200 in step a, a nitride film with excellent step coverage, in-plane thickness uniformity of the wafer 200, inter-wafer thickness uniformity, and thickness control can be formed on the wafer 200. Therefore, similarly, an oxide film formed by oxidizing this nitride film can also be produced with excellent step coverage, in-plane thickness uniformity of the wafer 200, inter-wafer thickness uniformity, and thickness control.

[0136] (h) In step b, the strong oxidizing power of oxide species such as atomic oxygen is used to oxidize the nitride film formed on the wafer 200. As a result, the oxide film formed on the wafer 200 can become a high-density and high-quality film with excellent etching resistance and insulation.

[0137] (i) Since steps a and b are performed in the same processing chamber 201 (in-situ), the processing time can be shortened compared to performing these steps in separate processing chambers (ex-situ). Furthermore, in this manner, the formation of a native oxide film (interfacial impurity) on the SiN film can be suppressed before performing step b.

[0138] (j) The same effect can be obtained when using the various gases containing the first element, N-containing gases, O-containing gases, H-containing gases, and inactive gases described above.

[0139] <Other ways of publishing this text>

[0140] In the above method, an example of forming a nitride film in step a and oxidizing the nitride film in step b to form an oxide film has been described. However, this disclosure is not limited to this. Other examples of film formation processes for forming an oxide film of a specified thickness on wafer 200 using this method are mainly used. Figure 6 , Figure 7 (a)~ Figure 7 (c) will be explained. It should be noted that in this method, the following mainly describes the processing steps and conditions that are different from those in the above method; the same processing steps and conditions are omitted.

[0141] In the film-forming process of this method, the following steps are performed:

[0142] Step c, which involves forming a film containing the first element on the wafer 200 by supplying a gas containing the first element to the wafer 200 in a processing chamber under an oxygen-free atmosphere; and

[0143] Step d, in which an oxide film is formed by oxidizing a membrane containing the first element by supplying oxygen-containing gas to the wafer 200,

[0144] In step d, the temperature of the wafer 200 is selected according to the thickness of the film containing the first element.

[0145] In the film-forming process sequence of this method,

[0146] In step c, the step of supplying the gas containing the first element to the wafer 200 is repeated a predetermined number of times (n times, where n is an integer greater than or equal to 1) to form a first element elemental membrane (hereinafter, sometimes simply referred to as an elemental membrane).

[0147] In addition, in the film-forming process sequence of this method,

[0148] In step d, O-containing gas and H-containing gas are simultaneously supplied to the wafer 200 in the processing chamber 201 which is under reduced pressure (below atmospheric pressure) to oxidize the first element element film and form an oxide film containing the first element (hereinafter, sometimes simply referred to as oxide film).

[0149] For convenience, the above film-forming process sequence is sometimes shown as follows in this specification.

[0150] Gas containing element 1 × n → (Gas containing O + Gas containing H)

[0151] Using the same processing steps as described above, the wafer 200 is moved into the processing chamber 201, and the pressure and temperature inside the processing chamber 201 are regulated.

[0152] (Formation of the first element's elemental membrane)

[0153] Then, through the same processing steps as described above, a gas containing the first element is supplied to the wafer 200 in the processing chamber 201.

[0154] As a processing condition for this step, an example can be given:

[0155] Gas supply flow rate containing element 1: 10–500 sccm, preferably 100–400 sccm

[0156] Inactive gas supply flow rate (per gas supply tube): 500–1500 sccm

[0157] Gas supply time: 1–300 seconds, preferably 10–120 seconds

[0158] Processing temperature (temperature of wafer 200): 300~550℃, preferably 400~550℃

[0159] Processing pressure (pressure inside processing chamber 201): 10-13300 Pa, preferably 300-1330 Pa.

[0160] In this step, if a chlorosilane-based gas, for example a Si-containing gas, is used as the gas containing the first element, a Si-containing layer, which is a layer containing the first element, is formed on the wafer 200 in the same manner as described above. Alternatively, other gases containing the first element as exemplified in the above-described manner can also be used as the gas containing the first element.

[0161] After forming the Si-containing layer, the supply of gas containing the first element to the processing chamber 201 is stopped through the same processing steps as described above. Then, the processing chamber 201 is evacuated through a vacuum through the same processing steps as described above to remove any remaining gases or other contaminants from the processing chamber 201 (purging). It should be noted that in the above method, an inert gas was used as the purging gas to remove any remaining gases or other contaminants from the processing chamber 201, but H2 gas can also be used as the purging gas instead of an inert gas or together with an inert gas.

[0162] [Perform the prescribed number of cycles]

[0163] By performing the above steps in a loop a specified number of times (n times, where n is an integer greater than or equal to 1), thus achieving... Figure 7As shown in (b), a Si film of a predetermined thickness can be formed on the surface of wafer 200 as a substrate. It should be noted that the Si film formed in step c as a first-element elemental film is oxidized in step d (described later), thereby expanding at a predetermined ratio and transforming into a SiO film as an oxide film containing the first element. In step c, it is preferable to consider this, i.e., the expansion ratio of the Si film, and perform an inverse operation based on the target film thickness of the SiO film to be formed in step d to determine the thickness of the Si film.

[0164] After the process of forming a Si film of the desired thickness on the wafer 200 is completed, the APC valve 244 is adjusted (pressure regulation) so that the pressure inside the processing chamber 201 is lower than the atmospheric pressure. In addition, the output power of the heater 207 is adjusted (temperature regulation) so that the temperature of the wafer 200 inside the processing chamber 201 is at the specified temperature.

[0165] (Formation of an oxide film containing element 1)

[0166] Then, oxygen-containing gas and hydrogen-containing gas are supplied to the wafer 200 in the processing chamber 201, that is, the Si film formed on the wafer 200 as a single-element film containing the first element.

[0167] As for the processing conditions in this step, the same processing conditions as those in the oxide film formation step containing the first element described above can be used as an example.

[0168] By supplying O-containing gas and H-containing gas to wafer 200 under the above conditions, thereby achieving... Figure 7 As shown in (c), the Si film formed on the wafer 200 as a first element elemental film is transformed into a SiO film as an oxide film containing the first element.

[0169] Furthermore, when the Si film is oxidized to form a SiO film under the above conditions, O is introduced into the Si film during the oxidation process, thereby causing it to expand at a predetermined ratio (expansion ratio). Therefore, the SiO film formed by performing step d becomes a film with a greater thickness than the Si film before oxidation (the Si film formed by performing step c). For example, if the thickness of the Si film formed by performing step c is set to... Under the above-described processing conditions, the thickness of the SiO film formed by step d is the thickness multiplied by its expansion ratio (approximately 2 times), i.e. The thickness on the left and right sides.

[0170] It should be noted that when the thickness of the Si film formed by step c is set as In this case, the selectable processing temperature for this step, as described above, is, for example, above 300°C and below 800°C. This is especially true when the thickness of the Si film is set to... In this case, the processing temperature that can be selected in this step, as described above, is preferably 300°C or higher and less than 600°C.

[0171] After the Si film is transformed into a SiO film, the supply of O-containing gas and H-containing gas to the processing chamber 201 is stopped through the same processing steps as described above.

[0172] After the process of forming a SiO film of the desired thickness on the wafer 200 is completed, the gas and reaction byproducts remaining in the processing chamber 201 are removed from the processing chamber 201 by the same processing steps as described above, and the processed wafer 200 is moved out of the reaction tube 203.

[0173] This method can achieve the same effect as the method described above.

[0174] <Other ways of publishing this text>

[0175] The foregoing has specifically described the manner of this disclosure. However, this disclosure is not limited to the manner described above and various changes may be made without departing from its spirit.

[0176] In the above description, an example was given in which all the N contained in the nitride film was removed from the film in step b, thereby transforming the nitride film into an oxide film; however, this disclosure is not limited thereto. For example, in step b, the N contained in the nitride film may remain in a predetermined proportion to form an oxynitride film (e.g., a silicon oxynitride film (SiON film)). The same effect as described above can be obtained in this way.

[0177] Furthermore, the above description focuses on an example where a nitride film is formed in step a and an oxide film is formed by oxidizing the nitride film in step b; however, this disclosure is not limited to this. For example, a carbide film (e.g., a silicon carbide film (SiC film)) may be formed on the wafer 200 in step a, and an oxygen carbide film (e.g., a silicon oxide carbide film (SiOC film)) may be formed by oxidizing the carbide film in step b. Alternatively, a carbonitride film (e.g., a silicon carbon nitride film (SiCN film)) may be formed in step a, and a carbonitride film (e.g., a silicon carbon nitride film (SiOCN film)) may be formed by oxidizing the carbonitride film in step b. By doing so, the same effects as described above can be obtained.

[0178] Furthermore, this disclosure can also be appropriately applied to the formation of oxide films containing metallic elements such as aluminum (Al), hafnium (Hf), zirconium (Zr), and titanium (Ti) on wafer 200, i.e., metal-based oxide films. That is, this disclosure can also be appropriately applied to the formation of aluminum oxide films (AlO films), hafnium oxide films (HfO films), zirconium oxide films (ZrO films), and titanium oxide films (TiO films) on wafer 200. In such cases, the same effects as described above can be obtained.

[0179] Furthermore, the above description focuses on an example where both O-containing gas and H-containing gas are simultaneously supplied to the wafer 200 as oxidizing gases in step b, but this disclosure is not limited to this. For example, the aforementioned O-containing gas may be supplied to the wafer 200 alone in step b without supplying the H-containing gas, thereby oxidizing films containing the first element, such as nitride films or elemental films containing the first element. Alternatively, plasma excitation may be performed on the O-containing gas, using active species containing O for oxidation. However, from the viewpoint of being able to perform oxidation treatment with strong oxidizing power, the method of simultaneously supplying O-containing gas and H-containing gas to the wafer 200 as described above is preferred.

[0180] The processes used in each process are prepared individually according to the processing content, and it is preferable to 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 rapid initiation of each process.

[0181] The aforementioned process is not limited to newly created cases; for example, it can also be prepared by modifying an existing process already installed in the substrate processing apparatus. In the case of process modification, the modified process can also be installed in the substrate processing apparatus via an electrical communication line and a recording medium containing the corresponding process. Alternatively, the input / output device 122 of an existing substrate processing apparatus can be operated to directly modify the existing process already installed in the substrate processing apparatus.

[0182] In the above-described method, an example of forming a film using a batch substrate processing apparatus that processes multiple substrates at a time has been described. This disclosure is not limited to the above-described method, and can also be suitably applied, for example, to cases where a monolithic substrate processing apparatus that processes one or more substrates at a time is used to form a film. Furthermore, in the above-described method, an example of forming a film using a substrate processing apparatus equipped with a hot-wall type furnace has been described. This disclosure is not limited to the above-described method, and can also be suitably applied to cases where a substrate processing apparatus equipped with a cold-wall type furnace is used to form a film.

[0183] When using the above-described substrate processing apparatus, each process can be performed using the same processing steps and conditions as described above, and the same effect as described above can be obtained.

[0184] 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.

[0185] Example

[0186] As an example, using Figure 1 The substrate processing apparatus shown utilizes the same processing steps and conditions as the substrate processing described above. In step a, a SiN film is formed on the wafer. In step b, the SiN film is oxidized to form an oxidized SiO film. During the formation of the SiO film, the oxidation amount (oxide film thickness) of the SiN film is measured at multiple predetermined times. The results are shown below. Figure 8 It should be noted that in step a, HCDS gas is used as the gas containing the first element, i.e., chlorosilane gas, and NH3 gas is used as the gas containing N. In step b, O2 gas is used as the gas containing O, and H2 gas is used as the gas containing H.

[0187] Figure 8 This is a graph showing the relationship between the time (hereinafter sometimes simply referred to as "supply time") for supplying O2 gas and H2 gas to a wafer with a SiN film formed, according to the processing temperature example, and the amount of oxidation (oxide film thickness) of the SiN film at the supply time. Figure 8 The horizontal axis indicates the supply time in [min]. Figure 8 The vertical axis is The amount of oxidation (oxide film thickness) of the SiN film is shown.

[0188] Figure 8 In the diagram, ● shows the amount of oxidation of the SiN film during a specified feed time at a processing temperature of 400°C. ▲ shows the amount of oxidation of the SiN film during a specified feed time at a processing temperature of 500°C. ■ shows the amount of oxidation of the SiN film during a specified feed time at a processing temperature of 600°C. ◆ shows the amount of oxidation of the SiN film at a specified feed time at a processing temperature of 700°C.

[0189] Specifically, for example, when the processing temperature is 400°C, if the feed time reaches approximately 100 minutes, the oxidation level of the SiN film will reach approximately... The oxidation level of the SiN film at a supply time of approximately 175 min is approximately Therefore, the oxide film thickness of the SiN film per unit time during the supply time of 100–175 min is for Therefore, it can be assumed that the oxidation reaction saturates around 100 minutes after the supply time is reached. Thus, the film thickness is... When oxidizing the SiN film, a processing temperature of 400°C is preferably selected. By selecting 400°C, the SiN film can be oxidized throughout its thickness direction at a time when the feed time reaches approximately 100 minutes, and the oxidation reaction is saturated. Therefore, even without strict control of the feed time, wafer oxidation can be suppressed. Furthermore, this allows for sufficient feed time, thus enabling the uniform formation of a SiO film over the entire surface area of ​​the wafer.

[0190] Additionally, for example, at a processing temperature of 500°C, if the feed time reaches approximately 125 minutes, the oxidation level of the SiN film reaches approximately [missing value]. The oxidation level of the SiN film at a supply time of approximately 175 min is approximately Therefore, the oxide film thickness of the SiN film per unit time during the supply time of 175–125 min is for Therefore, it can be assumed that the oxidation reaction saturates around 125 minutes after the supply time is reached. Thus, the film thickness is... When oxidizing the SiN film, a processing temperature of 500°C is preferably selected. By selecting 500°C, the SiN film can be oxidized throughout its thickness direction at a time when the feed time reaches approximately 125 minutes, and the oxidation reaction is saturated. Therefore, even without strict control of the feed time, wafer oxidation can be suppressed. Furthermore, this allows for sufficient feed time, thus enabling the uniform formation of a SiO film over the entire surface area of ​​the wafer.

[0191] Additionally, for example, when the processing temperature is 600°C, if the feed time reaches approximately 125 minutes, the oxidation level of the SiN film will reach approximately... The oxidation level of the SiN film at a supply time of approximately 175 min is approximately Therefore, the oxide film thickness of the SiN film per unit time during the supply time of 175–125 min is for Therefore, it can be assumed that the oxidation reaction saturates around 125 minutes after the supply time is reached. Thus, the film thickness is... When oxidizing the SiN film, a processing temperature of 600°C is preferably selected. By selecting 600°C, the SiN film can be oxidized throughout its thickness direction at a time when the feed time reaches approximately 125 minutes, and the oxidation reaction is saturated. Therefore, even without strict control of the feed time, wafer oxidation can be suppressed. Furthermore, this allows for sufficient feed time, thus enabling the uniform formation of a SiO film over the entire surface area of ​​the wafer.

[0192] Additionally, for example, at a processing temperature of 700°C, if the feed time reaches approximately 125 minutes, the oxidation level of the SiN film will reach approximately... The oxidation level of the SiN film at a supply time of approximately 175 min is approximately Therefore, the oxide film thickness of the SiN film per unit time during the supply time of 175–125 min is for The above. Therefore, it can be concluded that increasing the film thickness... When oxidizing SiN films, the preferred processing temperature is between 600°C and below 700°C.

[0193] Explanation of reference numerals in the attached figures

[0194] 200 wafers (substrates)

Claims

1. A substrate processing method, which has the following characteristics: (a) A process of forming a film containing the first element on a substrate constituting the surface of the substrate by supplying a gas containing the first element to the substrate in an oxygen-free atmosphere; and (b) A step of forming an oxide film by oxidizing the film containing the first element by supplying oxygen-containing gas to the substrate. In (b), different temperatures of the substrate are selected based on the thickness of the film containing the first element, and the temperature of the substrate is the temperature at which the oxidation reaction is saturated at the point in time when the film containing the first element is oxidized throughout its thickness direction, and the oxidation of the substrate in contact with the film containing the first element is suppressed.

2. The substrate processing method as described in claim 1, wherein, The oxidation reaction continues until the time point when the entire oxidation reaction of the membrane containing the first element is saturated (b).

3. The substrate processing method as described in claim 1, wherein, Until the rate of increase of the oxide film thickness of the film containing the first element per unit time becomes The following continues until (b).

4. The substrate processing method as described in claim 1, wherein, The thickness of the membrane containing the first element in (a) is determined in a manner that the oxide film formed by oxidizing and expanding the membrane containing the first element in (b) becomes the desired film thickness.

5. The substrate processing method as described in claim 1, wherein, In (a), the film containing the first element is formed on the surface of the substrate on which no oxide film has been formed in an oxygen-free atmosphere.

6. The substrate processing method as described in claim 1, wherein, In (a), the gas containing the first element is a gas in which the first element is silicon.

7. The substrate processing method as described in claim 6, wherein, In (a), a silicon nitride film is formed as the film containing the first element.

8. The substrate processing method as described in claim 6, wherein, In (a), a silicon film is formed as the film containing the first element.

9. The substrate processing method as described in claim 8, wherein, In (b), a silicon oxide film is formed as the oxide film.

10. The substrate processing method as described in claim 7, wherein, In (b), a silicon oxynitride film is formed as the oxide film.

11. The substrate processing method as described in claim 6, wherein, In (a), a silicon carbide film or a silicon carbon nitride film is formed as the film containing the first element.

12. The substrate processing method as described in claim 11, wherein, In (b), a silicon oxide carbide film or a silicon carbon oxide nitride film is formed as the oxide film.

13. The substrate processing method as described in claim 1, wherein, In (b), the oxygen-containing gas and the hydrogen-containing gas are supplied to the substrate under reduced pressure.

14. A method for manufacturing a semiconductor device, comprising: (a) A process of forming a film containing the first element on a substrate constituting the surface of the substrate by supplying a gas containing the first element to the substrate in an oxygen-free atmosphere; and (b) A step of forming an oxide film by oxidizing the film containing the first element by supplying oxygen-containing gas to the substrate. In (b), different temperatures of the substrate are selected based on the thickness of the film containing the first element, and the temperature of the substrate is the temperature at which the oxidation reaction is saturated at the point in time when the film containing the first element is oxidized throughout its thickness direction, and the oxidation of the substrate in contact with the film containing the first element is suppressed.

15. A substrate processing apparatus, comprising: The first gas supply unit supplies gas containing the first element; The second gas supply unit supplies oxygen-containing gas; and A control unit configured to control the first gas supply unit and the second gas supply unit in a manner comprising: (a) a process of forming a film containing the first element on a substrate constituting the surface of the substrate by supplying the gas containing the first element to the substrate in an oxygen-free atmosphere; and (b) a process of forming an oxide film by oxidizing the film containing the first element by supplying the oxygen-containing gas to the substrate, wherein, in (b), different temperatures of the substrate are selected according to the thickness of the film containing the first element, and the temperature of the substrate is a temperature at which the oxidation reaction is saturated at a time point when the film containing the first element is oxidized throughout its thickness direction, and the oxidation of the substrate in contact with the film containing the first element is suppressed.

16. A computer-readable recording medium having a program recorded thereon that enables a substrate processing apparatus to perform the following steps using a computer, the steps including: (a) A step of forming a film containing the first element on a substrate constituting the surface of the substrate by supplying a gas containing the first element to the substrate in an oxygen-free atmosphere; and (b) The step of forming an oxide film by oxidizing the film containing the first element by supplying oxygen-containing gas to the substrate. In (b), different temperatures of the substrate are selected based on the thickness of the film containing the first element, and the temperature of the substrate is the temperature at which the oxidation reaction is saturated at the point in time when the film containing the first element is oxidized throughout its thickness direction, and the oxidation of the substrate in contact with the film containing the first element is suppressed.

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