Semiconductor device manufacturing method, substrate processing method, recording medium and substrate processing device

Abstract

The present invention relates to a method for manufacturing a semiconductor device, a substrate processing method, a recording medium and a substrate processing device. The present invention can improve the characteristics of a film formed on a substrate. The method for manufacturing a semiconductor device of the present invention includes (a) and (b), (a): a process of forming a nitride film containing a predetermined element on a substrate by performing the following cycles (a-1), (a-2) and (a-3) in sequence for a predetermined number of times, (a-1) a process of supplying a first raw material gas containing a predetermined element to a substrate, (a-2) a process of supplying a second raw material gas containing a predetermined element and having a lower thermal decomposition temperature than the first raw material gas to a substrate, (a-3) a process of supplying a nitride gas to a substrate, (b): a process of supplying an oxidizing gas to a substrate to oxidize the nitride film formed in (a) and modify it into an oxide film containing a predetermined element.

Description

Technical Field

[0001] Disclosed are a method for manufacturing a semiconductor device, a substrate processing method, a recording medium, and a substrate processing device. Background Art

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

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-50425 Summary of the invention

[0006] Problems to be solved by the invention

[0007] An object of the present disclosure is to provide a technology capable of improving the characteristics of a film formed on a substrate.

[0008] Solution to the problem

[0009] According to one embodiment of the present disclosure, a method for manufacturing a semiconductor device is provided, comprising the following (a) and (b), (a): a process of forming a nitride film containing a predetermined element on a substrate by performing a predetermined number of cycles of the following (a-1), (a-2) and (a-3) in sequence, (a-1) supplying a first raw material gas containing the predetermined element to the substrate, (a-2) supplying a second raw material gas containing the predetermined element and having a lower thermal decomposition temperature than the first raw material gas to the substrate, (a-3) supplying a nitriding gas to the substrate; (b): a process of oxidizing the nitride film formed in (a) and converting it into an oxide film containing the predetermined element by supplying an oxidizing gas to the substrate.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to provide a technology capable of improving the characteristics of a film formed on a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus that is preferably used in one embodiment of the present disclosure, and is a diagram showing a processing furnace 202 portion in a vertical cross-sectional view.

[0013] Figure 2 This is a schematic diagram of a vertical processing furnace of a substrate processing device suitable for use in one embodiment of the present disclosure. Figure 1 The AA line cross-sectional view shows a portion of the processing furnace 202 .

[0014] Figure 3 1 is a schematic diagram of the configuration of a controller 121 of a substrate processing apparatus preferably used in one embodiment of the present disclosure, and is a diagram showing a control system of the controller 121 in the form of a block diagram.

[0015] Figure 4 It is a diagram showing a flow of a substrate processing step according to one embodiment of the present disclosure.

[0016] Figure 5 In the figure, (a) is a schematic diagram showing the surface state of the wafer 200 after the first raw material gas is supplied through stage a1, (b) is a schematic diagram showing the surface state of the wafer 200 after the second raw material gas is supplied through stage a2 after stage a1, and (c) is a schematic diagram showing the surface state of the wafer 200 after the nitriding gas is supplied through stage a3 after stage a2.

[0017] Figure 6 It is a graph showing the evaluation results of the film formed on the substrate.

[0018] Figure 7 It is a graph showing the evaluation results of the film formed on the substrate.

[0019] Figure 8 It is a graph showing the evaluation results of the film formed on the substrate.

[0020] Explanation of symbols

[0021] 200: wafer (substrate), 201: processing chamber. DETAILED DESCRIPTION

[0022] <One embodiment of the present disclosure>

[0023] Hereinafter, for one embodiment of the present disclosure, reference will be made mainly to Figure 1 to Figure 5 It should be noted that the drawings used in the following description are schematic diagrams, and the size relationship of each element, the ratio of each element, etc. shown in the drawings do not necessarily have to be consistent with the actual situation. In addition, the size relationship of each element, the ratio of each element, etc. between multiple drawings do not necessarily have to be the same.

[0024] (1) Configuration of substrate processing apparatus

[0025] like Figure 1 As shown, the processing furnace 202 has a heater 207 as a temperature adjuster (heating unit). The heater 207 is cylindrical and is supported by a holding plate and installed vertically. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) the gas by heat.

[0026] On the inner side of the heater 207, the 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 an upper end closed and a lower end open. Below the reaction tube 203, a header 209 is arranged concentrically with the reaction tube 203. The header 209 is made of a metal material such as stainless steel (SUS), and is formed into a cylindrical shape with both the upper and lower ends open. The upper end of the header 209 is associated with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a as a sealing member is provided between the header 209 and the reaction tube 203. The reaction tube 203 is installed vertically in the same manner as the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the header 209. The processing chamber 201 is formed in the hollow portion of the cylinder of the processing container. The processing chamber 201 is configured to accommodate a wafer 200 as a substrate. The wafer 200 is processed in the processing chamber 201 .

[0027] In the processing chamber 201, nozzles 249a to 249c as first to third supply parts are respectively arranged to penetrate the side wall of the manifold 209. The nozzles 249a to 249c may also be respectively referred to as first to third nozzles. The nozzles 249a to 249c are made of, for example, a heat-resistant material such as quartz or SiC. The nozzles 249a to 249c are respectively connected to the gas supply pipes 232a to 232c. The nozzles 249a to 249c are respectively different nozzles, and the nozzles 249b and 249c are respectively arranged adjacent to the nozzle 249a.

[0028] In the gas supply pipes 232a to 232c, mass flow controllers (MFC) 241a to 241c as flow controllers (flow control units) and valves 243a to 243c as switch valves are sequentially arranged from the upstream side of the gas flow. Gas supply pipes 232d and 232f are connected to the downstream side of the valve 243a of the gas supply pipe 232a, respectively. Gas supply pipes 232e and 232g are connected to the downstream side of the valve 243b of the gas supply pipe 232b. Gas supply pipe 232h is connected to the downstream side of the valve 243c of the gas supply pipe 232c. In the gas supply pipes 232d to 232h, MFCs 241d to 241h and valves 243d to 243h are sequentially arranged from the upstream side of the gas flow. The gas supply pipes 232a to 232h are made of metal materials such as SUS, for example.

[0029] like Figure 2As shown, the nozzles 249a to 249c are respectively arranged in the annular space between the inner wall of the reaction tube 203 and the wafer 200 when viewed from above, and are arranged to stand upright from the lower part to the upper part of the inner wall of the reaction tube 203 toward the upper part of the arrangement direction of the wafer 200. That is, in the area horizontally surrounding the wafer arrangement area on the side of the wafer arrangement area where the wafers 200 are arranged, the nozzles 249a to 249c are respectively arranged along the wafer arrangement area. The nozzle 249a is arranged to sandwich the center of the wafer 200 carried into the processing chamber 201 in a straight line opposite to the exhaust port 231a described later when viewed from above. The nozzles 249b and 249c are arranged to sandwich the straight line L passing through the center of the nozzle 249a and the exhaust port 231a from both sides along the inner wall of the reaction tube 203 (the outer periphery of the wafer 200). The straight line L is also a straight line passing through the nozzle 249a and the center of the wafer 200. That is, it can be said that the nozzle 249c is arranged on the opposite side of the nozzle 249b with the straight line L sandwiched therebetween. The nozzles 249b and 249c are arranged to be line symmetrical with the straight line L as the axis of symmetry. On the side surfaces of the nozzles 249a to 249c, gas supply holes 250a to 250c for supplying gas are respectively provided. The gas supply holes 250a to 250c are respectively opened in a manner opposite to (opposite to) the exhaust port 231a when viewed from above, and can supply gas to the wafer 200. A plurality of gas supply holes 250a to 250c are provided from the bottom to the top of the reaction tube 203.

[0030] From the gas supply pipe 232a, the first raw material gas (first raw material) containing the predetermined element is supplied to the processing chamber 201 via MFC241a, valve 243a, and nozzle 249a. As the first raw material gas, a gas that does not have bonds between atoms of the predetermined element in one molecule can be used. In addition, as the first raw material gas, a gas that has only one atom of the predetermined element in one molecule can be used. As the first raw material gas, a gas whose dissociation energy (i.e., the energy required when one molecule is decomposed into multiple molecules, etc.) is greater than the dissociation energy of the second raw material gas described later can be used. For example, if the dissociation caused by thermal energy is concerned, the first raw material gas can use a gas with a higher thermal decomposition temperature than the second raw material gas. In this specification, when the first raw material gas exists alone in the processing chamber 201, the dissociation temperature (thermal decomposition temperature) of the first raw material gas is sometimes referred to as the first temperature.

[0031] A hydrogen nitride-based gas, which is a gas containing nitrogen (N) and hydrogen (H), is supplied from the gas supply pipe 232b into the processing chamber 201 as a nitriding gas (nitriding agent) via the MFC 241b, the valve 243b, and the nozzle 249b.

[0032] A gas containing oxygen (O) is supplied as an oxidizing gas (oxidant) from the gas supply pipe 232 c into the processing chamber 201 via the MFC 241 c , the valve 243 c , and the nozzle 249 c .

[0033] From the gas supply pipe 232d, a second raw material gas (second raw material) containing the above-mentioned predetermined element and having a thermal decomposition temperature lower than that of the first raw material gas is supplied to the processing chamber 201 via MFC241d, valve 243d, gas supply pipe 232a, and nozzle 249a. As the second raw material gas, a gas having bonds between atoms of a predetermined element in one molecule can be used. In addition, as the second raw material gas, a gas having atoms of two or more predetermined elements in one molecule can be used. In addition, as the second raw material gas, a gas whose dissociation energy is smaller than the dissociation energy of the above-mentioned first raw material gas can be used. For example, if the dissociation caused by thermal energy is concerned, the second raw material gas can use a gas having a thermal decomposition temperature lower than that of the first raw material gas. In this specification, when the second raw material gas exists alone in the processing chamber 201, the dissociation temperature (thermal decomposition temperature) of the second raw material gas is sometimes referred to as the second temperature.

[0034] From the gas supply pipe 232e, a gas containing hydrogen (H) is supplied as a reducing gas (reducing agent) via the MFC 241e, the valve 243e, the gas supply pipe 232b, and the nozzle 249b into the processing chamber 201. The gas containing H cannot be oxidized by itself, but in the substrate processing step described later, it reacts with the gas containing O under specific conditions to generate oxidizing species such as atomic oxygen (O), thereby improving the oxidation processing efficiency. Therefore, it is also possible to consider incorporating the gas containing H into the oxidizing gas.

[0035] Inert gas is supplied from gas supply pipes 232f, 232g, 232h into the processing chamber 201 via MFCs 241f, 241g, 241h, valves 243f, 243g, 243h, gas supply pipes 232a, 232b, 232c, and nozzles 249a, 249b, 249c. The inert gas functions as a purge gas, a carrier gas, a dilution gas, and the like.

[0036] The first raw material gas supply system is mainly composed of a gas supply pipe 232a, MFC241a, and a valve 243a. The nitriding gas supply system is mainly composed of a gas supply pipe 232b, MFC241b, and a valve 243b. The oxidizing gas supply system is mainly composed of a gas supply pipe 232c, MFC241c, and a valve 243c. It is also possible to consider incorporating a gas supply pipe 232e, MFC241e, and a valve 243e into the oxidizing gas supply system. The second raw material gas supply system is mainly composed of a gas supply pipe 232d, MFC241d, and a valve 243d. The inactive gas supply system is mainly composed of gas supply pipes 232f to 232h, MFC241f to 241h, and valves 243f to 243h.

[0037] It should be noted that at least any one of the first raw material gas, the second raw material gas, the nitriding gas, and the oxidizing gas is also referred to as a film-forming gas, and at least any one of the first raw material gas supply system, the second raw material gas supply system, the nitriding gas supply system, and the oxidizing gas supply system is also referred to as a film-forming gas supply system.

[0038] Any or all of the various gas supply systems described above may also be configured as an integrated gas supply system 248 that is integrated with valves 243a to 243h, MFCs 241a to 241h, etc. The integrated gas supply system 248 is configured to be connected to the respective gas supply pipes 232a to 232h, and the controller 121 described later controls the supply of various gases to the gas supply pipes 232a to 232h, that is, the opening and closing of the valves 243a to 243h, the flow rate adjustment by the MFCs 241a to 241h, etc. The integrated supply system 248 is configured as an integrated unit of a one-piece or split type, and is configured in such a manner that the gas supply pipes 232a to 232h, etc., can be installed and removed as an integrated unit, and the integrated supply system 248 can be maintained, replaced, or added as an integrated unit.

[0039] An exhaust port 231a is provided below the side wall of the reaction tube 203 to exhaust the atmosphere in the processing chamber 201. Figure 2As shown, the exhaust port 231a is arranged at a position opposite to (facing) the nozzles 249a to 249c (gas supply holes 250a to 250c) sandwiching the wafer 200 when viewed from above. The exhaust port 231a can be arranged along the lower part to the upper part of the side wall of the reaction tube 203, that is, along the wafer arrangement area. The exhaust port 231a is connected to the exhaust pipe 231. The exhaust pipe 231 is made of a metal material such as SUS. The exhaust pipe 231 is connected to a vacuum pump 246 as a vacuum exhaust device via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). The APC valve 244 is configured to open and close the valve while the vacuum pump 246 is operating, thereby enabling vacuum exhaust in the processing chamber 201 and stopping vacuum exhaust. Furthermore, the valve opening is adjusted based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating, thereby enabling the pressure in the processing chamber 201 to be adjusted. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. It is also conceivable to incorporate the vacuum pump 246 into the exhaust system.

[0040] Below the manifold 209, a sealing cap 219 is provided as a furnace cover capable of hermetically closing the lower end opening of the manifold 209. The sealing cap 219 is made of a metal material such as SUS, for example, and is formed in a disc shape. On the upper surface of the sealing cap 219, an O-ring 220b is provided as a sealing member that abuts against the lower end of the manifold 209. Below the sealing cap 219, a rotating mechanism 267 is provided for rotating the wafer box 217 described later. The rotating shaft 255 of the rotating mechanism 267 is made of a metal material such as SUS, for example, and penetrates the sealing cap 219 and is connected to the wafer box 217. The rotating mechanism 267 is configured to rotate the wafer 200 by rotating the wafer box 217. The sealing cap 219 is configured to be lifted and lowered in the vertical direction by the wafer box elevator 115 as a lifting mechanism provided outside the reaction tube 203. The cassette elevator 115 is configured as a transport device (transport mechanism) that transports the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cap 219 .

[0041] A baffle 219s is provided below the manifold 209. The baffle 219s is a furnace cover that can hermetically close the lower end opening of the manifold 209 when the sealing cap 219 is lowered and the wafer box 217 is moved out of the processing chamber 201. The baffle 219s is made of a metal material such as SUS and is formed into a disc shape. An O-ring 220c is provided on the upper surface of the baffle 219s as a sealing member that abuts against the lower end of the manifold 209. The opening and closing actions (lifting and lowering actions, rotating actions, etc.) of the baffle 219s are controlled by the baffle opening and closing mechanism 115s.

[0042] The wafer box 217 as a substrate support is configured to support multiple (e.g., 25 to 200) wafers 200 in a horizontal posture and in a state where the centers are aligned with each other in a vertical direction in multiple stages, that is, multiple wafers are arranged at intervals. The wafer box 217 is made of, for example, a heat-resistant material such as quartz or SiC. At the bottom of the wafer box 217, it is supported in multiple stages by a heat insulation board 218 made of, for example, a heat-resistant material such as quartz or SiC.

[0043] A temperature sensor 263 as a temperature detector is provided in the reaction tube 203. By adjusting the energization of the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature in the processing chamber 201 can be adjusted to a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

[0044] like Figure 3 As shown, the controller 121 as a control unit (control unit) is configured as a computer having a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O interface 121d. The RAM 121b, the storage device 121c, and the I / O interface 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. The controller 121 is connected to an input / output device 122 configured as, for example, a touch panel.

[0045] The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. A control program for controlling the actions of the substrate processing device is stored in the storage device 121c, and a process recipe of the steps and conditions of the substrate processing described later is recorded and can be read out. The process recipe is a combination of the various steps in the substrate processing described later so that it is executed by the controller 121 and a predetermined result is obtained, and it functions as a program. Hereinafter, process recipes, control programs, etc. are simply collectively referred to as programs. In addition, process recipes are also simply referred to as recipes. When the term "program" is used in this specification, it includes the case of only a single recipe, the case of only a single control program, and the case of both. RAM121b is configured as a storage area (working area) for temporarily storing programs, data, etc. read by CPU121a.

[0046] The I / O interface 121d is connected to the above-mentioned MFC241a~241h, valves 243a~243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, wafer box elevator 115, shutter switch mechanism 115s, etc.

[0047] The CPU 121a is configured to read out a control program from the storage device 121c and execute it, and to read out a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is also configured to control, according to the contents of the read-out recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241h, the opening and closing operation of the valves 243a to 243h, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the wafer box 217 by the rotation mechanism 267, the lifting and lowering operation of the wafer box 217 by the wafer box elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, and the like.

[0048] The controller 121 can be constructed by installing the above-mentioned program stored in the external storage device 123 into the computer. The external storage device 123 includes, for example, magnetic disks such as HDD, optical disks such as CD, optical magnetic disks such as MO, USB memory, semiconductor memory such as SSD, etc. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium. Hereinafter, these are also simply collectively referred to as recording media. When the term "recording medium" is used in this specification, it includes the case of only a single storage device 121c, the case of only a single external storage device 123, or the case of both. It should be noted that providing a program to a computer can also be done without using an external storage device 123, but by using communication methods such as the Internet and dedicated lines.

[0049] (2) Substrate processing steps

[0050] Regarding an example of a process of processing a wafer 200 as a substrate as one of the steps of manufacturing a semiconductor device using the substrate processing apparatus described above, that is, an example of a film forming process of forming a film on the wafer 200, mainly using Figure 4 , Figure 5 (a)~ Figure 5 In the following description, the operation of each unit constituting the substrate processing apparatus is controlled by the controller 121.

[0051] In the film forming process of this method, the following nitride film formation and oxidation are performed:

[0052] Nitride film formation: a stage of forming a nitride film containing a predetermined element on the wafer 200 by performing a cycle of the following stages a1, a2, and a3 sequentially and non-simultaneously for a predetermined number of times (m times, where m is an integer greater than or equal to 1),

[0053] Phase a1: supplying a first source gas containing a predetermined element to the wafer 200,

[0054] Phase a2: supplying a second raw material gas containing a predetermined element and having a thermal decomposition temperature lower than that of the first raw material gas to the wafer 200,

[0055] Stage a3: supplying nitriding gas to the wafer 200;

[0056] Oxidation: A stage in which an oxidizing gas is supplied to the wafer 200 to oxidize the nitride film formed in the nitride film formation process and to convert the nitride film into an oxide film containing a predetermined element.

[0057] It should be noted that in the film forming process of this embodiment, an oxide film having a predetermined thickness is formed on the wafer 200 by performing a cycle of non-simultaneous nitride film formation and oxidation a predetermined number of times (n times, where n is an integer greater than or equal to 1).

[0058] In addition, in the film forming process of this method, before the nitride film is formed, a stage (pre-flow) of supplying hydrogen nitride gas to the wafer 200 is further performed. Specifically, a cycle of non-simultaneous nitride film formation and oxidation is performed a predetermined number of times (n times, n is an integer greater than 1), and pre-flow is performed each time each cycle is performed.

[0059] The following describes a case where the predetermined element contains silicon (Si). In this case, as the first raw material gas and the second raw material gas, a silane-based gas described later can be used. In addition, as the nitriding gas, a hydrogen nitride-based gas, which is a gas containing nitrogen (N) and hydrogen (H), can be used. In addition, as the oxidizing gas, a gas containing oxygen (O) and a gas containing hydrogen (H) can be used. In this case, in the nitride film formation, a silicon nitride film (SiN film) is formed on the wafer 200 as a nitride film. In the oxidation, the SiN film formed on the wafer 200 is modified into a silicon oxide film (SiO film) as an oxide film.

[0060] In this specification, for convenience, the above film forming process is represented as follows. The same representation is also used in the following description of modified examples and other embodiments.

[0061] [Hydrogen nitride gas → (first source gas → second source gas → nitride gas) × m

[0062] →Oxidizing gas〕×n

[0063] In this specification, when the term "wafer" is used, it includes the meaning of "the wafer itself" and the meaning of "a stack of a wafer and a predetermined layer, film, etc. formed on its surface." In this specification, when the term "wafer surface" is used, it includes the meaning of "the surface of the wafer itself" and the meaning of "the surface of a predetermined layer, etc. formed on the wafer." In this specification, when it is recorded as "a predetermined layer is formed on the wafer," it includes the meaning of "a predetermined layer is directly formed on the surface of the wafer itself" and the meaning of "a predetermined layer is formed on a layer, etc. formed on the wafer." In this specification, when the term "substrate" is used, it has the same meaning as when the term "wafer" is used.

[0064] (Wafer loading and wafer cassette loading)

[0065] After a plurality of wafers 200 are loaded into the wafer box 217 (wafer loading), the shutter 219s is moved by the shutter opening mechanism 115s to open the lower end opening of the manifold 209 (shutter opening). Figure 1 As shown, the wafer cassette 217 supporting a plurality of wafers 200 is lifted by the wafer cassette elevator 115 and carried into the processing chamber 201 (wafer cassette loading). In this state, the sealing cap 219 is in a state of closing the lower end of the manifold 209 via the O-ring 220b.

[0066] (Pressure adjustment and temperature adjustment)

[0067] After the wafer box is loaded, the vacuum pump 246 performs vacuum exhaust (decompression exhaust) so that the space in the processing chamber 201 where the wafer 200 exists reaches the desired pressure (vacuum degree). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback controlled (pressure adjusted) based on the measured pressure information. In addition, the heater 207 heats the wafer 200 in the processing chamber 201 so that it reaches the desired processing temperature. At this time, the power supply to the heater 207 is feedback controlled based on the temperature information detected by the temperature sensor 263 so that the desired temperature distribution (temperature adjustment) is achieved in the processing chamber 201. In addition, the rotation of the wafer 200 is started by the rotating mechanism 267. The exhaust in the processing chamber 201, the heating and rotation of the wafer 200 are all continued at least until the processing of the wafer 200 is completed.

[0068] (Film forming treatment)

[0069] Then, the subsequent pre-flow, nitride film formation, and oxidation are performed in sequence.

[0070] [Pre-flow]

[0071] In this stage, hydrogen nitride-based gas is supplied to the wafer 200 in the processing chamber 201 .

[0072] Specifically, valve 243b is opened to allow hydrogen nitride gas to flow into gas supply pipe 232b. The flow rate of hydrogen nitride gas is adjusted by MFC241b, supplied to processing chamber 201 via nozzle 249b, and exhausted by exhaust pipe 231. At this time, hydrogen nitride gas is supplied to wafer 200 (hydrogen nitride gas is supplied). At this time, valves 243f to 243h are opened to supply inactive gas into processing chamber 201 via nozzles 249a to 249c, respectively. It should be noted that in the various methods shown below, supply of inactive gas into processing chamber 201 may not be implemented.

[0073] The processing conditions in this stage are exemplified as follows:

[0074] Hydrogen nitride gas supply flow rate: 100-10000sccm,

[0075] Inert gas supply flow rate (each gas supply pipe): 0~20000sccm,

[0076] Each gas supply time: 1 to 30 minutes,

[0077] Treatment temperature: 300-1000°C, preferably 700-900°C, more preferably 750-800°C,

[0078] Processing pressure: 1-4000Pa, preferably 20-1333Pa.

[0079] Here, the representation of a numerical range such as "1 to 4000Pa" in this specification means that the lower limit and the upper limit are included in the range. Therefore, for example, "1 to 4000Pa" means "above 1Pa and below 4000Pa". The same applies to other numerical ranges. It should be noted that the processing temperature in this specification refers to the temperature of the wafer 200, and the processing pressure refers to the pressure in the processing chamber 201 (i.e., the space where the wafer 200 exists). In addition, when the gas supply flow rate is recorded as 0sccm, it means that the gas is not supplied. This is also the case in the following descriptions.

[0080] A natural oxide film or the like is sometimes formed on the surface of the wafer 200 before the film forming process is performed. By supplying a hydrogen nitride-based gas to the wafer 200 under the above conditions, an NH termination can be formed on the surface of the wafer 200 on which a natural oxide film or the like is formed. As a result, in the nitride film formation described later, the desired film forming reaction can be efficiently performed on the wafer 200. The NH termination formed on the surface of the wafer 200 can be considered to have the same meaning as the H termination. In addition, by performing the stage of oxidizing the nitride film and modifying it into an oxide film described later, the NH termination on the surface of the wafer 200 is sometimes reduced, so it is preferred to perform pre-flow for each cycle in which the nitride film formation and oxidation are not performed simultaneously. However, considering that performing pre-flow for each cycle will lead to a decrease in output, pre-flow may not be performed after each cycle in which the nitride film formation and oxidation are not performed simultaneously. In addition, pre-flow may be performed every predetermined number of times (p times, p is an integer greater than 2 and p<n) in which the nitride film formation and oxidation are not performed simultaneously.

[0081] After the NH termination is formed on the surface of the wafer 200 by pre-flow, the valve 243b is closed to stop the supply of hydrogen nitride gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove (purge) the residual gas in the processing chamber 201. At this time, the valves 243f to 243h are opened to supply an inert gas into the processing chamber 201.

[0082] As the hydrogen nitride-based gas, for example, ammonia (NH 3 ) gas, diimide (N 2 H 2 ) gas, hydrazine (N 2 H 4 ) gas, N 3 H 8 gas, etc. can be used. As the hydrogen nitride-based gas, one or more of these can be used.

[0083] As the inert gas, for example, inert gases such as nitrogen (N2) gas, argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas can be used. As the inert gas, one or more of these can be used. This is also the same in each stage described later.

[0084] [Nitride film formation]

[0085] After the pre-flow is completed, the nitride film is formed. In this stage, the following stages a1 to a3 are performed in sequence.

[0086] [Phase a1]

[0087] In this stage, the first source gas is supplied to the wafer 200 in the processing chamber 201 .

[0088] Specifically, valve 243a is opened to allow the first raw material gas to flow into the gas supply pipe 232a. The flow rate of the first raw material gas is adjusted by MFC241a, supplied to the processing chamber 201 via nozzle 249a, and exhausted by exhaust pipe 231. At this time, the first raw material gas is supplied to the wafer 200 (the first raw material gas is supplied). At this time, valves 243f to 243h are opened to supply inactive gas to the processing chamber 201 via nozzles 249a to 249c, respectively. It should be noted that in the various methods shown below, it is also possible not to supply inactive gas to the processing chamber 201.

[0089] The processing conditions in this stage are exemplified as follows:

[0090] First raw material gas supply flow rate: 1 to 2000 sccm, preferably 100 to 1000 sccm,

[0091] Inert gas supply flow rate (each gas supply pipe): 100~20000sccm,

[0092] Each gas supply time: 10 to 300 seconds, preferably 30 to 120 seconds,

[0093] Treatment temperature: 400 to 900° C., preferably 500 to 800° C., more preferably 600 to 750° C. (a temperature lower than the first temperature, preferably a temperature lower than the first temperature and higher than the second temperature),

[0094] Processing pressure: 1-2666Pa, preferably 10-1333Pa.

[0095] Other processing conditions may be the same as those in the above-mentioned pre-flow.

[0096] As the first raw material gas, for example, tetrachlorosilane (SiCl4) gas is used, and this stage is carried out under the above conditions, thereby cutting a part of the Si-Cl bonds in SiCl4, so that Si with unpaired electrons can be adsorbed on the adsorption site on the surface of the wafer 200. In addition, under the above conditions, the Si-Cl bonds that are not cut in SiCl4 can remain as they are. For example, in a state where three of the four paired electrons of Si constituting SiCl4 are respectively combined with Cl, Si with unpaired electrons can be adsorbed on the adsorption site on the surface of the wafer 200. In addition, the Cl that is not cut from the Si adsorbed on the surface of the wafer 200 and remains hinders the combination of the Si with other Si with unpaired electrons, thereby avoiding multiple accumulation of Si on the wafer 200. The Cl cut from Si will form gaseous substances such as HCl and Cl2, which are exhausted by the exhaust pipe 231. If the adsorption reaction of Si is performed and there are no remaining adsorption sites on the surface of the wafer 200, the adsorption reaction reaches saturation. However, in this stage, it is desired to stop supplying the first raw material gas before the adsorption reaction reaches saturation and end this stage in a state where there are remaining adsorption sites.

[0097] As a result, a layer containing Si and Cl having a substantially uniform thickness less than one atomic layer thickness, that is, a Si-containing layer containing Cl is formed as a first layer on the wafer 200 . Figure 5 (a) is a schematic diagram showing the surface state of the wafer 200 on which the first layer is formed. Here, the layer less than 1 atomic layer thick means an atomic layer formed discontinuously, and the layer 1 atomic layer thick means an atomic layer formed continuously. In addition, the layer less than 1 atomic layer thick is roughly uniform, which means that atoms are adsorbed on the surface of the wafer 200 with a roughly uniform density. Since the first layer is formed on the wafer 200 with a roughly uniform thickness, it has excellent step coverage characteristics and uniformity of film thickness within the wafer surface.

[0098] It should be noted that when SiCl4 gas is used as the first raw material gas, if the processing temperature is lower than 400°C, it is difficult to adsorb Si on the wafer 200, and it is sometimes difficult to form the first layer. By setting the processing temperature to 400°C or higher, the first layer can be formed on the wafer 200. By setting the processing temperature to 500°C or higher, the above effect can be obtained reliably. By setting the processing temperature to 600°C or higher, the above effect can be obtained more reliably.

[0099] When SiCl4 gas is used as the first raw material gas, if the processing temperature exceeds 900°C, it is difficult for the uncut Si-Cl bonds in the molecular structure to remain intact, and the thermal decomposition rate of the first raw material gas will increase. As a result, multiple Si deposits will be deposited on the wafer 200, and it is sometimes difficult to form a Si-containing layer with a roughly uniform thickness of less than 1 atomic layer thickness as the first layer. It should be noted that in this case, the above-mentioned first temperature associated with the first raw material gas can be considered to be a predetermined temperature within the range exceeding 900°C. By setting the processing temperature below 900°C, a Si-containing layer with a roughly uniform thickness of less than 1 atomic layer thickness can be formed as the first layer. By setting the processing temperature below 750°C, the above-mentioned effect can be reliably obtained.

[0100] After the first layer is formed on the wafer 200, the valve 243a is closed to stop supplying the first source gas into the processing chamber 201. Then, the gas remaining in the processing chamber 201 is exhausted (purged) from the processing chamber 201 in the same processing steps as the purge in the pre-flow.

[0101] As the first raw material gas, a halosilane gas having a molecular structure containing only silicon (Si) as a predetermined element, having no Si-Si bond and containing a halogen element bonded to Si can be used. Halogen elements include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As the first raw material gas, for example, a chlorosilane gas containing Si and Cl can be used.

[0102] As the first raw material gas, in addition to SiCl4 gas, for example, chlorosilane gas such as monochlorosilane (SiH3Cl) gas, dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, etc. can be used. As the first raw material gas, one or more of these can be used. As the first raw material gas, in addition to chlorosilane gas, for example, fluorosilane gas such as tetrafluorosilane (SiF4) gas, difluorosilane (SiH2F2) gas, bromosilane gas such as tetrabromosilane (SiBr4) gas, dibromosilane (SiH2Br2) gas, iodosilane gas such as tetraiodosilane (SiI4) gas, diiodosilane (SiH2I2) gas, etc. can also be used.

[0103] [Phase a2]

[0104] In this stage, the second source gas is supplied to the wafer 200 in the processing chamber 201 , that is, to the first layer formed on the wafer 200 .

[0105] Specifically, valve 243d is opened to allow the second raw material gas to flow into the gas supply pipe 232d. The second raw material gas is controlled by MFC241d, supplied to the processing chamber 201 via the gas supply pipe 232a and the nozzle 249a, and exhausted by the exhaust pipe 231. At this time, the second raw material gas is supplied to the wafer 200 (the second raw material gas is supplied). At this time, valves 243f to 243h are opened to supply inactive gas to the processing chamber 201 via the nozzles 249a to 249c, respectively. It should be noted that in the various methods shown below, it is also possible not to supply inactive gas to the processing chamber 201.

[0106] The processing conditions in this stage are exemplified as follows:

[0107] The second raw material gas supply flow rate is 1 to 2000 sccm, preferably 100 to 1000 sccm.

[0108] Inert gas supply flow rate (each gas supply pipe): 0~20000sccm,

[0109] Each gas supply time: 0.5 to 60 seconds, preferably 1 to 30 seconds,

[0110] Treatment temperature: 500 to 1000° C., preferably 600 to 800° C., more preferably 650 to 750° C. (a temperature higher than the second temperature, preferably a temperature higher than the second temperature and lower than the first temperature).

[0111] Other processing conditions may be the same as those in the above-mentioned pre-flow.

[0112] As the second raw material gas, for example, hexachlorodisilane (Si2Cl6) gas is used. By performing this stage under the above conditions, Si2Cl6 can be thermally decomposed, and the Si having unpaired electrons can react with the adsorption sites on the surface of the wafer 200 that remain without forming the first layer in stage a1, and adsorb on the surface of the wafer 200. At this time, since the Si-Si bonds contained in the molecular structure are cut due to thermal decomposition, molecules containing Si having unpaired electrons are generated. On the other hand, since there are no adsorption sites in the portion where the first layer is formed, the adsorption of Si to the first layer is suppressed. As a result, in this stage, based on the first layer with a roughly uniform thickness formed on the surface of the wafer 200, a Si-containing layer as the second layer is formed with a roughly uniform thickness on the surface of the wafer 200. In addition, Si having unpaired electrons due to the thermal decomposition of the second raw material gas is combined with each other to form Si-Si bonds. By reacting these Si-Si bonds with the adsorption sites remaining on the surface of the wafer 200, etc., it is possible to make the second layer contain Si-Si bonds, and a layer formed by multiple Si stacking can be formed. That is, through this stage, the amount (content ratio) of Si-Si bonds contained in the second layer can be made larger than the amount (content ratio) of Si-Si bonds contained in the first layer. Cl separated from Si will form gaseous substances such as HCl and Cl2, which are exhausted by the exhaust pipe 231.

[0113] It should be noted that, in order to make the amount of Si-Si bonds contained in the second layer greater than the amount of Si-Si bonds contained in the first layer through this stage, as described above, it is good that the temperature at which the second raw material gas dissociates (the temperature at which thermal decomposition occurs) is lower than the temperature at which the first raw material gas dissociates (the temperature at which thermal decomposition occurs). In other words, it is desirable that the second raw material gas is a gas that is easier to form bonds between atoms of a predetermined element than the first raw material gas under the same conditions. For example, it is good that the molecules of the second raw material gas contain bonds between atoms of a predetermined element. In addition, for example, it is appropriate that the ratio of the content of a predetermined element such as Si to the content of a halogen element such as Cl in the molecules of the second raw material gas, that is, the composition ratio is greater than the composition ratio of the first raw material gas. In this way, the selection of processing conditions such as the processing temperature in each stage and the selection of the first raw material gas and the second raw material gas are performed so that in this stage, compared with stage a1, the bonds between atoms of the predetermined element that react at the adsorption sites remaining on the wafer surface are easier to form.

[0114] As a result, in this stage, a Si-containing layer having a substantially uniform thickness exceeding the thickness of the first layer is formed as the second layer. In view of improving the film formation rate, in this embodiment, a Si-containing layer having a substantially uniform thickness exceeding one atomic layer is formed as the second layer. Figure 5(b) is a schematic diagram showing the surface state of the wafer 200 on which the second layer is formed. It should be noted that in this specification, the second layer means a Si-containing layer on the wafer 200 formed by performing the step a1 and the step a2 once each.

[0115] It should be noted that when Si2Cl6 gas is used as the second raw material gas, if the processing temperature is lower than 500°C, the gas is difficult to be thermally decomposed, and sometimes it is difficult to form the second layer. By setting the processing temperature to 500°C or higher, the second layer can be formed on the first layer. By setting the processing temperature to 600°C or higher, the above effect can be obtained reliably. By setting the processing temperature to 650°C or higher, the above effect can be obtained more reliably.

[0116] When Si2Cl6 gas is used as the second raw material gas, if the processing temperature exceeds 1000°C, the second raw material gas will be over-thermally decomposed, and the accumulation of Si that has not reached self-saturation tends to proceed quickly, so it is sometimes difficult to form a roughly uniform second layer. By setting the processing temperature below 1000°C, the excessive thermal decomposition of the second raw material gas can be suppressed, and the accumulation of Si that has not reached self-saturation can be controlled, so that the second layer can be formed roughly uniformly. It should be noted that in this case, the above-mentioned second temperature related to the second raw material gas can be considered to be a predetermined temperature within the range exceeding 1000°C. By setting the processing temperature below 800°C, the above-mentioned effect can be reliably obtained. By setting the processing temperature below 750°C, the above-mentioned effect can be more reliably obtained.

[0117] In addition, it is desirable that the temperature conditions in stages a1 and a2 are substantially the same. Thus, there is no need to change the temperature of the wafer 200 between stages a1 and a2, that is, there is no need to change the temperature in the processing chamber 201 (change in the set temperature of the heater 207), and thus there is no need for a standby time for the temperature of the wafer 200 to reach a stable state between stages, which can increase the output of substrate processing. Therefore, the temperature of the wafer 200 can be set to a predetermined temperature within the range of, for example, 500 to 900°C, preferably 600 to 800°C, and more preferably 650 to 750°C in both stages a1 and a2. In this embodiment, when the temperature conditions in stages a1 and a2 are substantially the same, the temperature conditions and the first raw material gas and the second raw material gas are selected so that the thermal decomposition of the first raw material gas does not substantially occur (i.e., is suppressed) in stage a1, and the thermal decomposition of the second raw material gas occurs (i.e., is promoted) in stage a2.

[0118] After the second layer is formed on the wafer 200, the valve 243d is closed to stop supplying the second source gas into the processing chamber 201. Then, the gas remaining in the processing chamber 201 is exhausted (purged) from the processing chamber 201 in the same processing steps as the purge in the pre-flow.

[0119] As the second raw material gas, a halosilane gas having a molecular structure containing silicon (Si) containing two or more predetermined elements, having a Si-Si bond and containing a halogen element bonded to Si can be used. Halogen elements include Cl, F, Br, I, etc. As the second raw material gas, for example, a chlorosilane gas containing Si and Cl can be used. As the second raw material gas, in addition to Si2Cl6 gas, for example, chlorosilane gas such as monochlorodisilane (Si2H5Cl) gas, dichlorodisilane (Si2H4Cl2) gas, trichlorodisilane (Si2H3Cl3) gas, tetrachlorodisilane (Si2H2Cl4) gas, monochlorotrisilane (Si3H5Cl) gas, and dichlorotrisilane (Si3H4Cl2) gas can be used. As the second raw material gas, one or more of these can be used.

[0120] As the second raw material gas, an aminosilane-based gas having a molecular structure containing silicon (Si) of two or more predetermined elements, having a Si-Si bond and containing an amino group bonded to Si can be used. As the second raw material gas, for example, aminosilane-based gases such as tris(dimethylamino)silane (Si[N(CH3)2]3H) gas and bis(diethylamino)silane (SiH2[N(C2H5)2]2) gas can be used. As the second raw material gas, one or more of these can be used. By using a non-halogen gas as the second raw material gas, it is possible to avoid mixing halogens into the film finally formed on the wafer 200.

[0121] [Phase a3]

[0122] In this stage, a nitriding gas is supplied to the wafer 200 in the processing chamber 201 , that is, to the layer formed by stacking the first layer and the second layer formed on the wafer 200 .

[0123] Specifically, valve 243b is opened to allow nitriding gas to flow into gas supply pipe 232b. The flow rate of nitriding gas is controlled by MFC241b, supplied to processing chamber 201 via nozzle 249b, and exhausted by exhaust pipe 231. At this time, nitriding gas is supplied to wafer 200 (nitriding gas is supplied). At this time, valves 243f to 243h are opened to supply inactive gas into processing chamber 201 via nozzles 249a to 249c, respectively. It should be noted that in the various methods shown below, supplying inactive gas into processing chamber 201 may not be implemented.

[0124] The processing conditions in this stage are exemplified as follows:

[0125] Nitriding gas supply flow rate: 100 to 10,000 sccm, preferably 1,000 to 5,000 sccm,

[0126] Inert gas supply flow rate (each gas supply pipe): 0~20000sccm,

[0127] Each gas supply time: 1 to 120 seconds, preferably 10 to 60 seconds,

[0128] Processing pressure: 1-4000Pa, preferably 10-1000Pa.

[0129] The other treatment conditions were the same as those in the above-mentioned pre-flow.

[0130] As the nitriding gas, for example, hydrogen nitride gas is used, and by performing this stage under the above conditions, at least a portion of the second layer can be nitrided. Cl contained in the second layer constitutes a gaseous substance such as HCl and Cl2, which is exhausted by the exhaust pipe 231. As a result, a silicon nitride layer (SiN layer) as a nitrided layer containing Si and N is formed on the wafer 200 as the third layer. Figure 5 (c) is a partially enlarged view showing the surface of the wafer 200 on which the third layer is formed.

[0131] After the third layer is formed on the wafer 200, the valve 243b is closed to stop the supply of the nitriding gas into the processing chamber 201. Then, the gas remaining in the processing chamber 201 is exhausted (purged) from the processing chamber 201 in the same processing steps as the purging in the pre-flow.

[0132] As the nitriding gas, for example, ammonia (NH3) gas, diimide (N2H2) gas, hydrazine (N2H4) gas, N3H8 gas or other hydrogen nitride-based gas can be used. As the nitriding gas, one or more of these can be used. In addition, the same hydrogen nitride-based gas as that used in the preflow can be used as the nitriding gas.

[0133] [Scheduled number of implementations]

[0134] By performing the cycle of the above-mentioned stages a1 to a3 non-simultaneously, i.e., non-synchronously, for a predetermined number of times (m times, where m is an integer greater than 1), a nitride film having a predetermined composition ratio and a predetermined film thickness can be formed on the wafer 200. The above-mentioned cycle is preferably repeated multiple times. That is, it is preferred that the thickness of the nitride layer formed in each cycle is less than the desired film thickness, and the above-mentioned cycle is repeated multiple times until the desired film thickness is reached. However, the thickness of the nitride film formed on the wafer 200 by performing the predetermined number of cycles is preferably such that the effect of oxidation performed after this stage can spread over the entire thickness of the nitride film.

[0135] During the formation of the nitride film, in order to make the ratio of a predetermined element (Si) in the nitride film formed on the wafer 200 greater than the ratio of the predetermined element in the nitride film when the nitride film has a stoichiometric composition (for example, in the case of a SiN film, Si:N=3:4) (that is, the film becomes a film rich in the predetermined element), it is preferred to adjust at least any one of the following ratios: the ratio of the supply time T1 of the first raw material gas in stage a1 to the supply time T2 of the second raw material gas in stage a2, the ratio of the supply flow rate F1 of the first raw material gas in stage a1 to the supply flow rate F2 of the second raw material gas in stage a2, and the ratio of the processing pressure P1 in stage a1 to the processing pressure P2 in stage a2.

[0136] For example, by making the supply time T2 of the second raw material gas in stage a2 longer than the supply time T1 of the first raw material gas in stage a1 (by making T2 / T1>1), the ratio of a predetermined element in the nitride film formed on the wafer 200 can be controlled in an increasing direction (in the direction of becoming a composition rich in the predetermined element).

[0137] In addition, for example, by making the supply flow rate F2 of the second raw material gas in stage a2 greater than the supply flow rate F1 of the first raw material gas in stage a1 (by making F2 / F1>1), the ratio of a predetermined element in the nitride film formed on the wafer 200 can be controlled in an increasing direction (in the direction of becoming a composition rich in the predetermined element).

[0138] In addition, for example, by making the processing pressure P2 in stage a2 higher than the processing pressure P1 in stage a1 (by making P2 / P1>1), the ratio of a predetermined element in the nitride film formed on the wafer 200 can be controlled in an increasing direction (in the direction of becoming a composition rich in the predetermined element).

[0139] [Oxidation]

[0140] After the nitride film formation is completed, an oxidizing gas is supplied to the wafer 200 in the processing chamber 201 , that is, the SiN film formed on the wafer 200 .

[0141] Specifically, the valves 243c and 243e are opened, and the gas containing O and the gas containing H are respectively flowed into the gas supply pipes 232c and 232e. The flow rates of the gas containing O and the gas containing H flowing into the gas supply pipes 232c and 232e are adjusted by the MFCs 241c and 241e, respectively, and supplied to the processing chamber 201 through the gas supply pipe 232b and the nozzles 249c and 249b. The gas containing O and the gas containing H are mixed and reacted in the processing chamber 201, and then exhausted from the exhaust port 231a. At this time, an oxidizing species containing oxygen such as atomic oxygen generated by the reaction of the gas containing O and the gas containing H but not containing water (H2O) is supplied to the wafer 200 heated in the reduced pressure atmosphere (supplying the gas containing O+the gas containing H). At this time, the valves 243f to 243h are opened, and the inert gas is respectively supplied to the processing chamber 201 through the nozzles 249a to 249c. It should be noted that in the various methods described below, supply of the inert gas into the processing chamber 201 may not be performed.

[0142] The processing conditions in this stage are exemplified as follows:

[0143] O-containing gas supply flow rate: 100 to 10,000 sccm, preferably 1,000 to 5,000 sccm,

[0144] H-containing gas supply flow rate: 100 to 10,000 sccm, preferably 1,000 to 5,000 sccm,

[0145] Inert gas supply flow rate (each gas supply pipe): 0~20000sccm,

[0146] Each gas supply time: 1 to 120 seconds, preferably 10 to 60 seconds,

[0147] Processing pressure: 1-2000Pa, preferably 10-1333Pa.

[0148] Other processing conditions may be the same as those in the above-mentioned pre-flow.

[0149] As the oxidizing gas, for example, a gas containing O+a gas containing H is used. By performing this stage under the above conditions, the nitride film, i.e., the SiN film, formed on the wafer 200 can be oxidized and modified into a film containing Si and O, i.e., a silicon oxide film (SiO film) as an oxide film. It should be noted that by appropriately adjusting the thickness of the nitride film formed on the wafer 200 in the above nitride film formation, the oxidation effect of this stage can be spread over the entire nitride film. That is, the entire nitride film can be modified into an oxide film.

[0150] After the nitride film formed on the wafer 200 is modified into an oxide film, the valves 243c and 243e are closed to stop the supply of the gas containing O and the gas containing H into the processing chamber 201. Then, the gas remaining in the processing chamber 201 is removed (purged) from the processing chamber 201 according to the same processing steps as the purge in the above-mentioned pre-flow.

[0151] As the oxidizing gas, oxygen (O2) gas + hydrogen (H2 gas), ozone (O3) gas, water vapor (H2O gas), gas containing O radicals, gas containing OH radicals, gas containing plasma-excited O2, etc. can be used. As the oxidizing gas, one or more of these can be used.

[0152] (Scheduled number of implementations)

[0153] By performing the above-mentioned pre-flow, nitride film formation, and oxidation cycles non-simultaneously, i.e., non-synchronously, for a predetermined number of times (n times, where n is an integer greater than 1), a SiO film with a predetermined composition ratio and a predetermined film thickness can be formed on the wafer 200. It should be noted that the above-mentioned cycles are preferably repeated multiple times. That is, it is preferred that the thickness of the oxide film formed in each cycle is smaller than the desired film thickness, and the above-mentioned cycles are repeated multiple times until the desired film thickness is reached.

[0154] (Post-purge and atmospheric pressure recovery)

[0155] After the oxide film of the desired thickness is formed on the wafer 200, an inactive gas is supplied from the nozzles 249a to 249c as a purge gas into the processing chamber 201, and the gas is exhausted from the exhaust port 231a. Thus, the processing chamber 201 is purged, and the residual gas, reaction by-products, etc. in the processing chamber 201 are removed from the processing chamber 201 (post-purge). Then, the atmosphere in the processing chamber 201 is replaced with an inactive gas (inactive gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure restoration).

[0156] (Cassette unloading and wafer release)

[0157] Then, the sealing cap 219 is lowered by the wafer box elevator 115 to open the lower end of the manifold 209. Then, the processed wafer 200 is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 in a state supported by the wafer box 217 (wafer box unloading). After the wafer box is unloaded, the baffle 219s is moved to seal the lower end opening of the manifold 209 through the O-ring 220c by the baffle 219s (close the baffle). After the processed wafer 200 is carried out to the outside of the reaction tube 203, it is taken out from the wafer box 217 (wafer release).

[0158] (3) Effects of this method

[0159] According to this aspect, one or more of the following effects are obtained.

[0160] (a) In this method, two stages, stage a1 of supplying the first raw material gas and stage a2 of supplying the second raw material gas, are performed in one cycle, so that the step coverage characteristics of the nitride film formed on the wafer 200, the uniformity of the film thickness within the wafer surface, and the effect of increasing the film formation rate of the film can be achieved at the same time. Therefore, the step coverage characteristics of the oxide film finally formed on the wafer 200, the uniformity of the film thickness within the wafer surface, and the effect of increasing the film formation rate of the film can be achieved at the same time.

[0161] This is because, if the first raw material gas having a higher thermal decomposition temperature than the second raw material gas and being difficult to thermally decompose is supplied to the wafer 200 under the above-mentioned processing conditions, a first layer having a substantially uniform thickness less than one atomic layer thickness will be formed on the wafer 200. If the stage a2 is not performed, and only the cycle of the stage a1 of supplying the first raw material gas and the stage a3 of supplying the nitriding gas is performed sequentially for a predetermined number of times, in this case, since the thickness of the nitride layer formed in each cycle is uniform throughout the wafer surface, the step coverage characteristics and the uniformity of the film thickness within the wafer surface of the nitride film finally formed on the wafer 200 can be made good. On the other hand, since the thickness of the nitride layer formed in each cycle is thin, it is sometimes difficult to increase the film formation rate of the nitride film formed on the wafer 200. That is, it is difficult to take into account both the effect of improving the step coverage characteristics and the uniformity of the film thickness within the wafer surface of the oxide film finally formed on the wafer 200 and the effect of increasing the film formation rate of the film.

[0162] On the other hand, if a second raw material gas having a lower thermal decomposition temperature than the first raw material gas and being easy to thermally decompose is supplied to the wafer 200 under the above-mentioned processing conditions, a second layer having bonds between predetermined elements and having a thickness exceeding one atomic layer will be formed on the wafer 200. If stage a1 is not performed, and only the cycle of stage a2 of supplying the second raw material gas and stage a3 of supplying the nitriding gas is performed sequentially for a predetermined number of times, in this case, since the thickness of the nitride layer formed in each cycle is thick, the film formation rate of the nitride film finally formed on the wafer 200 can be achieved to be good. On the other hand, since the thickness of the nitride layer formed in each cycle is prone to be uneven within the wafer surface, it is sometimes difficult to improve the step coverage characteristics and the uniformity of the film thickness within the wafer surface of the nitride film formed on the wafer 200. That is, it is difficult to take into account both the effect of improving the step coverage characteristics and the uniformity of the film thickness within the wafer surface of the oxide film finally formed on the wafer 200 and the effect of improving the film formation rate of the film.

[0163] In this method, since both stage a1 and stage a2 are performed, the respective effects obtained by each stage can be taken into account. For example, before the adsorption reaction of the predetermined element on the wafer 200 reaches saturation, stage a1 is stopped and stage a2 with a higher film forming rate is performed instead, which can increase the film forming rate compared to the case where only stage a1 is performed at the same time. In addition, after forming a first layer with better thickness uniformity in stage a1, a second layer is formed based on the first layer in stage a2, thereby, compared to the case where only stage a2 is performed, the step coverage characteristics of the nitride film formed on the wafer 200 and the uniformity of the film thickness within the wafer surface can be improved. That is, it is possible to take into account the effects of improving the step coverage characteristics of the oxide film finally formed on the wafer 200, the uniformity of the film thickness within the wafer surface, and the effect of increasing the film forming rate of the film.

[0164] (b) In this method, in each cycle, stage a1 is performed before stage a2, and then stage a2 is performed, thereby fully utilizing the step coverage characteristics and the uniformity of the film thickness within the wafer surface of the nitride film finally formed on the wafer 200, while improving its film formation rate. Thus, the step coverage characteristics and the uniformity of the film thickness within the wafer surface of the oxide film finally formed on the wafer 200 can be fully utilized, while improving its film formation rate.

[0165] If, in each cycle, stage a2 is performed before stage a1 and then stage a1 is performed, in this case, atoms having bonds between predetermined elements generated by thermal decomposition in stage a2 tend to be irregularly adsorbed on the surface of the wafer 200, and a layer with uneven thickness may be formed in the wafer surface as a base of the layer to be formed in stage a1. Therefore, stage a1, which forms a layer of approximately uniform thickness in the middle of the film forming process, tends to lose its technical significance.

[0166] In contrast, in the present method, in each cycle, stage a1 is performed before stage a2 and then stage a2 is performed, thereby forming a layer of substantially uniform thickness as a base of the layer to be formed in stage a2. Therefore, the technical significance of stage a1 of forming a layer of substantially uniform thickness in the middle of the film forming process can be fully utilized.

[0167] (c) In this embodiment, the composition ratio of a predetermined element and N in the nitride film formed on the wafer 200 can be widely controlled. Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition.

[0168] This is because, by reducing the ratio B / A of the amount of the second raw material gas supplied to the substrate in each cycle relative to the amount of the first raw material gas supplied to the substrate in each cycle, the ratio of the bonds between the predetermined elements contained in the second layer can be reduced, and the thickness of the second layer can be controlled in a thinning direction. By thinning the second layer (i.e., the layer to be nitrided in stage a3), the composition ratio of the nitride film formed on the wafer 200 can be controlled in a direction in which the composition ratio of the predetermined element becomes smaller (i.e., the predetermined element is depleted). For example, by reducing the ratio B / A, the thickness of the second layer can be thinned within a range of more than one atomic layer. Thus, the composition ratio of the predetermined element can be controlled in a direction close to becoming smaller relative to the composition ratio in the stoichiometric composition of the nitride film. Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition.

[0169] In addition, by increasing B / A, the ratio of bonds between predetermined elements contained in the second layer can be increased, and the thickness of the second layer can be controlled in the direction of becoming thicker. By thickening the second layer (i.e., the layer to be nitrided in stage a3), the composition ratio of the nitride film formed on the wafer 200 can be controlled in the direction of increasing the composition ratio of the predetermined element (i.e., enriching the predetermined element). For example, by increasing the ratio B / A, the thickness of the second layer can be thickened within a range of more than 1 atomic layer thickness. Thus, the composition ratio of the predetermined element can be controlled in the direction of becoming larger relative to the composition ratio in the stoichiometric composition of the nitride film. Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition.

[0170] In addition, when the nitride film formed on the wafer 200 is a SiN film or the like, the greater the composition ratio of N in the nitride film (i.e., the smaller the composition ratio of the predetermined element), the smaller the oxidation rate in the subsequent oxidation process becomes. Therefore, by making the composition of the nitride film formed on the wafer 200 rich in the predetermined element, the efficiency of the subsequent oxidation process can be improved, and the formation rate of the oxide film can be increased. In addition, even if the thickness of the nitride film formed in each cycle is increased, it is easy to make the oxidation effect spread throughout the entire nitride film, which can improve the output.

[0171] It should be noted that the above B / A can be controlled, for example, by adjusting the ratio T2 / T1 of the supply time T2 of the second raw material gas in each cycle to the supply time T1 of the first raw material gas in each cycle, that is, by adjusting the supply time of the first raw material gas and the second raw material gas in each cycle. In addition, the above B / A can also be controlled by adjusting the ratio F2 / F1 of the supply flow rate F2 of the second raw material gas to the supply flow rate F1 of the first raw material gas.

[0172] In addition, by adjusting the magnitude of the processing pressure P2 in the stage a2 and controlling the thermal decomposition rate of the second raw material gas, it is also possible to control the ratio of the content of the predetermined element to the content of N in the nitride film formed on the wafer 200, that is, the composition ratio. Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition.

[0173] For example, by reducing the processing pressure P2, the thickness of the second layer can be controlled to be thinner. By thinning the second layer (i.e., the layer to be nitrided in stage a3), the composition ratio of the nitride film formed on the wafer 200 can be controlled in a direction where the composition ratio of the predetermined element becomes smaller. Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition.

[0174] In addition, by making the processing pressure P2 greater than the processing pressure P1 in stage a1, the thickness of the second layer can be controlled to become thicker. By making the second layer (i.e., the layer to be nitrided in stage a3) thicker, the composition ratio of the nitride film formed on the wafer 200 can be controlled in the direction of increasing the composition ratio of the predetermined element (i.e., enriching the predetermined element). Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition. In addition, by making the composition of the nitride film formed on the wafer 200 rich in the predetermined element, the efficiency of the subsequent oxidation treatment can be improved, and the formation rate of the oxide film can be increased.

[0175] (d) In this method, since the processing temperature of stage a1 is lower than the thermal decomposition temperature (first temperature) of the first raw material gas, and the processing temperature of stage a2 is higher than the thermal decomposition temperature (second temperature) of the second raw material gas, the above-mentioned effect can be reliably obtained.

[0176] This is because, in stage a1, since the processing temperature is set to a temperature lower than the first temperature, the thermal decomposition of the first raw material gas can be suppressed, and the step coverage characteristics and the uniformity of the film thickness in the wafer surface of the nitride film formed on the wafer 200 can be improved. In addition, the composition ratio of the nitride film can be controlled in a direction close to the composition ratio in the stoichiometric composition. As a result, the step coverage characteristics and the uniformity of the film thickness in the wafer surface of the oxide film finally formed on the wafer 200 can be improved, and the composition of the film can be adjusted to a desired composition.

[0177] In addition, in stage a2, since the processing temperature is set to a temperature higher than the second temperature, the appropriate thermal decomposition of the second raw material gas can be maintained, and the film formation rate of the nitride film formed on the wafer 200 can be increased. In addition, the composition ratio of the nitride film can be controlled to be rich in a predetermined element. Thus, the composition of the oxide film finally formed on the wafer 200 can be adjusted to a desired composition. In addition, by making the composition of the nitride film formed on the wafer 200 rich in a predetermined element, the efficiency of the subsequent oxidation treatment can be improved, and the formation rate of the oxide film can be increased.

[0178] (e) The above-mentioned effects can be similarly obtained when using the above-mentioned various hydrogen nitride-based gases, the above-mentioned various first raw material gases, the above-mentioned various second raw material gases, the various nitriding gases, the above-mentioned various oxidizing gases, and the above-mentioned various inert gases.

[0179] <Other aspects of the present disclosure>

[0180] The embodiments of the present disclosure have been specifically described above, but the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present disclosure.

[0181] In the above-mentioned method, an example is described in which a series of stages from nitride film formation to oxidation are performed in the same processing chamber 201 (in-situ). However, the present disclosure is not limited to such a method. For example, nitride film formation and oxidation can also be performed in separate processing chambers (non-in-situ). In this case, the same effect as that in the above-mentioned method can be obtained. If a series of stages are performed in-situ, the wafer 200 is not exposed to the atmosphere in the middle, the wafer 200 can be placed in a vacuum for continuous processing, and stable substrate processing can be performed. In addition, if a part of the stages is performed non-in-situ, the temperature in each processing chamber can be pre-set, for example, at the processing temperature of each stage or a temperature close thereto, thereby shortening the time required for temperature adjustment and improving production efficiency.

[0182] In the above method, an example is described in which the implementation time period of stage a1 does not overlap with the implementation time period of stage a2. The present disclosure is not limited to this. For example, the implementation time period of stage a1 may overlap at least a part of the implementation time period of stage a2. In this way, in addition to the above effects, the cycle time can be shortened and the output of substrate processing can be increased.

[0183] The recipes for each treatment are preferably prepared separately according to the treatment content, and stored in the storage device 121c via the communication circuit and the external storage device 123. Moreover, it is preferred that when each treatment is started, the CPU 121a appropriately selects a suitable recipe from the multiple recipes stored in the storage device 121c according to the treatment content. Thus, a variety of film types, composition ratios, film qualities, and film thicknesses can be formed with good reproducibility by one substrate processing device. In addition, the burden on the operator can be reduced, operational errors can be avoided, and various treatments can be started quickly.

[0184] The above-mentioned recipe is not limited to the case of newly making, and can also be prepared by, for example, changing an existing recipe already installed in a substrate processing device. When changing a recipe, the changed recipe can be installed in the substrate processing device via a communication circuit or a recording medium recording the recipe. In addition, the input / output device 122 of the existing substrate processing device can be operated to directly change the existing recipe already installed in the substrate processing device.

[0185] In the above-mentioned method, an example of forming a film using a batch-type substrate processing device that processes multiple substrates at a time is described. The present disclosure is not limited to the above-mentioned method, and can also be well applied when a film is formed using a single-piece substrate processing device that processes one or more substrates at a time. In addition, in the above-mentioned method, an example of forming a film using a substrate processing device with a hot wall type processing furnace is described. The present disclosure is not limited to the above-mentioned method, and can also be well applied when a film is formed using a substrate processing device with a cold wall type processing furnace.

[0186] When these substrate processing apparatuses are used, each process can be performed by the same processing steps and processing conditions as those of the above-mentioned embodiments and modified examples, and the same effects as those of the above-mentioned embodiments and modified examples can be obtained.

[0187] In addition, in the above-mentioned method, as the oxide film to be formed, an example of forming a SiO film is described. The present disclosure is not limited to the above-mentioned method, and can also be well applied when forming an oxide film containing at least one element selected from metal elements and Group 14 elements as a predetermined element. Here, the metal element refers to, for example, aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), molybdenum (Mo), lanthanum (La), etc. The Group 14 element refers to, for example, germanium (Ge).

[0188] The above-mentioned embodiments and modified examples may be used in combination as appropriate. The processing steps and processing conditions in this case may be, for example, the same as those of the above-mentioned embodiments and modified examples.

[0189] Example

[0190] As samples 1 and 2, use Figure 1The substrate processing apparatus shown forms a nitride film (SiN film) on a wafer.

[0191] Without performing stage a2, sample 1 is prepared by performing a cycle of alternately performing stage a1 and stage a3 for a predetermined number of times. The processing conditions in each stage are predetermined conditions within the range of processing conditions described in the above method. Without performing stage a1, sample 2 is prepared by performing a cycle of alternately performing stage a2 and stage a3 for a predetermined number of times. The processing conditions in stage a2 are predetermined conditions within the range of processing conditions described in the above method. The other processing conditions are the same as those when preparing sample 1.

[0192] Then, the film thickness of the nitride film of each sample was measured per cycle number. The results are shown in Figure 6 . Figure 6 The horizontal axis represents the number of cycles, and the vertical axis represents the thickness of the nitride film. according to Figure 6 It can be seen that the nitride film of Sample 2 produced using the second source gas has a shorter incubation time and a higher cycle rate than the nitride film of Sample 1 produced using the first source gas.

[0193] In addition, as samples 3 and 4, Figure 1 The substrate processing apparatus shown forms a SiN film on a wafer having a groove structure with a groove width of about 50 nm, a groove depth of about 10 μm, and an aspect ratio of about 200 on the surface.

[0194] Sample 3 was prepared by performing a predetermined number of cycles of alternately performing stages a2 and a3 without performing stage a1. Sample 4 was prepared by performing a predetermined number of cycles of stages a1 to a3 in sequence. Specifically, in sample 4, the supply time of the first raw material gas in stage a1 was set to 60 seconds. In samples 3 and 4, the supply time of the second raw material gas in stage a2 was set to 9 seconds respectively. Other processing conditions, including the number of cycles and the amount of gas supplied, were the same as those in the above-mentioned processing conditions.

[0195] Then, the Top / Bottom ratio (%) in the nitride films of Samples 3 and 4 was measured respectively. Figure 7 The results are displayed. "Top / Bottom ratio (%)" is the ratio of the film thickness formed on the upper part of the groove of the groove structure to the film thickness formed on the lower part of the groove of the groove structure, expressed as a percentage. When the film thickness formed on the upper part and the lower part of the groove of the groove structure are set to C and D respectively, the Top / Bottom ratio (%) is calculated by the formula C / D×100.

[0196] according to Figure 7It can be seen that the Top / Bottom ratio in Sample 4 is greater than the Top / Bottom ratio in Sample 3 (close to 100). That is, it can be seen that the nitride film of Sample 4 produced by supplying both the first raw material gas and the second raw material gas has excellent step coverage characteristics and film thickness uniformity within the wafer surface, compared with the nitride film of Sample 3 produced by supplying only the second raw material gas without supplying the first raw material gas.

[0197] In addition, as samples 5 and 6, Figure 1 The substrate processing apparatus shown forms an oxide film (SiO film) on the wafer by oxidizing a nitride film formed on the wafer.

[0198] When forming a nitride film, stage a2 was not performed, and a cycle of alternately performing stage a1 and stage a3 was performed a predetermined number of times to produce sample 5. When forming a nitride film, a cycle of sequentially performing stages a1 to a3 was performed a predetermined number of times to produce sample 6. The processing conditions in each stage were the same conditions within the range of the processing conditions in the above-mentioned method. The number of repetitions (n ​​times) of the cycle including nitride film formation and oxidation was 3 times for each sample.

[0199] Then, the processing time (au) required for the oxide films of samples 5 and 6 to reach a predetermined film thickness was measured. Figure 8 Display the results. Figure 8 The horizontal axis represents each sample, and the vertical axis represents the processing time (au) required for the oxide film to reach a predetermined film thickness. Figure 8 It can be seen that compared with sample 5 in which stage a2 is not performed when forming a nitride film, sample 6 in which stages a1 to a3 are cycled a predetermined number of times to form a nitride film requires a shorter processing time, that is, a higher film formation rate is obtained.

Claims

1. A substrate processing method, comprising the following (a) and (b), (a): A step of forming a nitride film containing a predetermined element on a substrate by performing the following cycles of (a-1), (a-2) and (a-3) in sequence for a predetermined number of times, (a-1) supplying a first source gas containing the predetermined element and a halogen element to the substrate, (a-2) supplying a second raw material gas containing the predetermined element and a halogen element and having a thermal decomposition temperature lower than that of the first raw material gas to the substrate, (a-3) supplying a nitriding gas to the substrate, (b): A step of supplying an oxidizing gas to the substrate to oxidize the nitride film formed in (a) and convert it into an oxide film containing the predetermined element.

2. The substrate processing method according to claim 1, wherein: The oxide film having a predetermined thickness is formed on the substrate by performing the cycle of (a) and (b) a predetermined number of times.

3. The substrate processing method according to claim 2, wherein: The thickness of the nitride film formed in (a) is set to a thickness at which the oxidation effect in (b) extends over the entire thickness direction of the nitride film.

4. The substrate processing method according to any one of claims 1 to 3, wherein: (a) and (b) are performed in the same processing chamber.

5. The substrate processing method according to any one of claims 1 to 3, wherein: As the first raw material gas, a gas having a dissociation energy greater than that of the second raw material gas is used. The dissociation energy is the energy required to decompose one molecule into a plurality of molecules.

6. The substrate processing method according to any one of claims 1 to 3, wherein: The first raw material gas does not have bonds between atoms of the predetermined element in one molecule, The second source gas has bonds between atoms of the predetermined element in one molecule.

7. The substrate processing method according to claim 6, wherein: The first raw material gas has only one atom of the predetermined element in one molecule, The second raw material gas has two or more atoms of the predetermined element in one molecule.

8. The substrate processing method according to any one of claims 1 to 3, wherein: The first raw material gas is at least one gas selected from the group consisting of SiCl4 gas, SiH2Cl2 gas, SiH3Cl gas, and SiHCl3 gas, The second raw material gas is at least one gas selected from the group consisting of Si2Cl6 gas, Si2H5Cl gas, Si2H4Cl2 gas, Si2H3Cl3 gas, Si2H2Cl4 gas, Si3H5Cl gas, and Si3H4Cl2 gas.

9. The substrate processing method according to any one of claims 1 to 3, wherein: In (a-1), the temperature of the substrate is set to a temperature at which the first raw material gas does not thermally decompose, and in (a-2), the temperature of the substrate is set to a temperature at which the second raw material gas thermally decomposes.

10. The substrate processing method according to any one of claims 1 to 3, wherein: With the following (c), (c): Before performing step (a), a step of supplying a hydrogen nitride-based gas to the substrate.

11. The substrate processing method according to claim 10, wherein: The cycle of (a) and (b) is repeated a predetermined number of times, and (c) is performed each time the cycle is repeated.

12. The substrate processing method according to claim 10, wherein: The nitriding gas is the hydrogen nitride-based gas.

13. The substrate processing method according to claim 10, wherein: The hydrogen nitride-based gas is at least one gas selected from the group consisting of NH3 gas, N2H2 gas, N2H4 gas, and N3H8 gas.

14. The substrate processing method according to any one of claims 1 to 3, wherein: The oxidizing gas is at least one gas selected from the group consisting of O2 gas, O3 gas, O2 gas and H2 gas, H2O gas, gas containing O radicals, gas containing OH radicals, and gas containing plasma-excited O2.

15. The substrate processing method according to any one of claims 1 to 3, wherein: In (b), O 2 gas and H 2 gas are supplied to the substrate heated in a reduced pressure atmosphere.

16. The substrate processing method according to any one of claims 1 to 3, wherein: In (a), any one of the following ratios is adjusted so that the ratio of the predetermined element in the nitride film is greater than the ratio of the predetermined element in the nitride film when the nitride film has a stoichiometric composition: The ratio of the supply time of the first raw material gas in (a-1) to the supply time of the second raw material gas in (a-2), The ratio of the supply flow rate of the first raw material gas in (a-1) to the supply flow rate of the second raw material gas in (a-2), The ratio of the treatment pressure in (a-1) to the treatment pressure in (a-2).

17. The substrate processing method according to claim 16, wherein: The supply time of the second raw material gas in (a-2) is made longer than the supply time of the first raw material gas in (a-1).

18. The substrate processing method according to claim 16, wherein: The supply flow rate of the second raw material gas in (a-2) is set to be larger than the supply flow rate of the first raw material gas in (a-1).

19. The substrate processing method according to claim 16, wherein: The treatment pressure in (a-2) is made higher than the treatment pressure in (a-1).

20. A method for manufacturing a semiconductor device, comprising the following (a) and (b), (a): A step of forming a nitride film containing a predetermined element on a substrate by performing the following cycles of (a-1), (a-2) and (a-3) in sequence for a predetermined number of times, (a-1) supplying a first source gas containing the predetermined element and a halogen element to the substrate, (a-2) supplying a second raw material gas containing the predetermined element and a halogen element and having a thermal decomposition temperature lower than that of the first raw material gas to the substrate, (a-3) supplying a nitriding gas to the substrate, (b): A step of supplying an oxidizing gas to the substrate to oxidize the nitride film formed in (a) and convert it into an oxide film containing the predetermined element.

21. A computer-readable recording medium having a program recorded thereon for causing a substrate processing apparatus to execute the following (a) and (b) via a computer, (a): a step of forming a nitride film containing a predetermined element on a substrate by performing the following cycles of (a-1), (a-2) and (a-3) in sequence for a predetermined number of times, (a-1) supplying a first raw material gas containing the predetermined element and a halogen element to the substrate, (a-2) supplying a second raw material gas containing the predetermined element and a halogen element and having a thermal decomposition temperature lower than that of the first raw material gas to the substrate, (a-3) supplying a nitriding gas to the substrate, (b): A step of oxidizing the nitride film formed in (a) by supplying an oxidizing gas to the substrate to convert the nitride film into an oxide film containing the predetermined element.

22. A substrate processing device comprising: a first raw material gas supply system for supplying a first raw material gas containing a predetermined element and a halogen element to the substrate; a second raw material gas supply system for supplying a second raw material gas containing the predetermined element and a halogen element and having a thermal decomposition temperature lower than that of the first raw material gas to the substrate; a nitriding gas supply system for supplying nitriding gas to the substrate; an oxidizing gas supply system for supplying an oxidizing gas to the substrate, and a control unit configured to control the first raw material gas supply system, the second raw material gas supply system, the nitriding gas supply system, and the oxidizing gas supply system to perform the following processes (a) and (b), (a): a process of forming a nitride film containing the predetermined element on the substrate by performing the following cycles (a-1), (a-2) and (a-3) in sequence for a predetermined number of times, (a-1) supplying the first raw material gas to the substrate, (a-2) supplying the second raw material gas to the substrate, (a-3) supplying the nitriding gas to the substrate, (b): A process of oxidizing the nitride film formed in (a) and converting it into an oxide film containing the predetermined element by supplying the oxidizing gas to the substrate.

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