Substrate processing method, semiconductor device manufacturing method, substrate processing system, and program

Abstract

Provided is a substrate processing method comprising: (a) supplying a raw material, a first reaction body, and a second reaction body to a substrate having a first film and a second film on the surface thereof under conditions in which the raw material is not thermally decomposed and physical adsorption of the raw material is more dominant than chemical adsorption when the raw material is present alone; a step for forming a third film on the first film and the second film; and (b) a step for removing the first film while holding the second film and the third film by exposing the surface of the substrate on which the third film is formed on the first film and the second film to an etchant that reacts with the first film.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method, a method for manufacturing a semiconductor device, a substrate processing system, and a program. Background Art

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

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-64836 Summary of the invention

[0006] Problems to be solved by the invention

[0007] As semiconductor devices become smaller, there is a strong demand for forming air gaps on substrates with high accuracy and precision.

[0008] The present disclosure provides a technology capable of forming an air gap with high accuracy and precision.

[0009] Methods for solving problems

[0010] According to one embodiment of the present disclosure, a technology is provided, comprising:

[0011] (a) a process of forming a third film on the first film and the second film by supplying a raw material, a first reactant, and a second reactant to a substrate having a first film and a second film on its surface, in the presence of a raw material alone, under conditions where the raw material does not undergo thermal decomposition and physical adsorption of the raw material is more dominant than chemical adsorption, thereby supplying the raw material, a first reactant, and a second reactant; and

[0012] (b) A step of removing the first film while maintaining the second film and the third film by exposing the surface of the substrate having the third film formed on the first film and the second film to an etchant that reacts with the first film.

[0013] Effects of the Invention

[0014] According to the present disclosure, an air gap can be formed with high accuracy and precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] [ Figure 1 ] Figure 1 This is a schematic configuration diagram of a vertical processing furnace of a substrate processing system that is preferably used in each embodiment of the present disclosure, and shows a processing furnace portion in a vertical cross-sectional view.

[0016] [ Figure 2 ] Figure 2 This is a schematic diagram of a vertical processing furnace of a substrate processing system suitable for use in each embodiment of the present disclosure. Figure 1 The AA line cross-sectional view shows a diagram of a processing furnace portion.

[0017] [ Figure 3 ] Figure 3 This is a schematic configuration diagram of a controller of a substrate processing system that is preferably used in each embodiment of the present disclosure, and is a diagram showing a control system of the controller in the form of a block diagram.

[0018] [ Figure 4 ] Figure 4 This is a diagram showing a substrate processing procedure in one embodiment of the present disclosure.

[0019] [ Figure 5 ] Figure 5 (a) is a partial cross-sectional enlarged view showing a surface portion of a wafer in one embodiment of the present disclosure having a first film and a second film on the surface. Figure 5 (b) is a partial cross-sectional enlarged view showing a wafer surface portion in one embodiment of the present disclosure after initial layers are formed on the first film and the second film. Figure 5 (c) is a partial cross-sectional enlarged view showing a wafer surface portion in one embodiment of the present disclosure after the third film is formed on the initial layer. Figure 5 (d) is a partial cross-sectional enlarged view of the wafer surface in one embodiment of the present disclosure after the air gap is formed by removing the first film while maintaining the second film and the third film. Figure 5 (e) is a partial cross-sectional enlarged view of the wafer surface in one embodiment of the present disclosure after the fourth film is formed on the third film.

[0020] [ Figure 6 ] Figure 6 (a) is a partial cross-sectional enlarged view showing a surface portion of a wafer in another embodiment of the present disclosure having a first film and a second film on the surface. Figure 6 (b) is a partial cross-sectional enlarged view showing a wafer surface portion in another embodiment of the present disclosure after initial layers are formed on the first film and the second film. Figure 6 (c) is a partial cross-sectional enlarged view showing a wafer surface portion in another embodiment of the present disclosure after a third film is formed on the initial layer. Figure 6 (d) is a partial cross-sectional enlarged view of the wafer surface in another embodiment of the present disclosure after forming an air gap by removing a portion of the first film while maintaining the second film and the third film. Figure 6 (e) is a partial cross-sectional enlarged view of the wafer surface in another embodiment of the present disclosure after the fourth film is formed on the third film.

[0021] [ Figure 7 ] Figure 7(a) is a TEM image of a portion of a wafer surface in an example in which a first film and a second film are present on the surface. Figure 7 (b) is a TEM image of a portion of the wafer surface in the example after the initial layer and the third film are formed on the first film and the second film. Figure 7 (c) is a TEM image of a portion of the wafer surface in the example after the wafer surface after the third film is formed is exposed to an etchant for 30 minutes. Figure 7 (d) is a TEM image of a portion of the wafer surface in Example after the wafer surface after the third film is formed is exposed to an etchant for 60 minutes. Figure 7 (e) is a TEM image of a portion of the wafer surface in Example after the wafer surface after the third film is formed is exposed to an etchant for 90 minutes. Figure 7 (f) is a TEM image of a portion of the wafer surface in an example in which the wafer surface after the third film is formed is exposed to an etchant for 25 minutes and a fourth film is formed on the third film. Figure 7 (g) is a TEM image of a portion of the wafer surface in an example in which a plurality of air gaps are formed by removing a portion of the first film while maintaining the second film and the third film, and then a fourth film is formed on the third film. DETAILED DESCRIPTION

[0022] <One aspect of the present disclosure>

[0023] Hereinafter, for one aspect of the present disclosure, reference will be made mainly to Figure 1 to Figure 4 , Figure 5 (a)~ Figure 5 (e) Description. It should be noted that the drawings used in the following description are schematic diagrams, and the dimensional relationship of each element, the ratio of each element, etc. shown in the drawings do not necessarily have to be consistent with reality. In addition, the dimensional 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 system (substrate processing apparatus)

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

[0026] On the inner side of the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and is formed into a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS), and is formed into a cylindrical shape with both the upper and lower ends open. The upper end of the manifold 209 cooperates 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 manifold 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 manifold 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 are respectively provided as first to third supply parts in a manner penetrating the side wall of the manifold 209. The nozzles 249a to 249c are also 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 different nozzles, and the nozzles 249a and 249c are respectively provided adjacent to the nozzle 249b.

[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 opening and closing valves are provided in order from the upstream side of the gas flow. A gas supply pipe 232e is connected to the downstream side of the valve 243a of the gas supply pipe 232a. Gas supply pipes 232d and 232f are connected to the downstream side of the valve 243b of the gas supply pipe 232b, respectively. A gas supply pipe 232g is connected to the downstream side of the valve 243c of the gas supply pipe 232c. In the gas supply pipes 232d to 232g, MFCs 241d to 241g and valves 243d to 243g are provided in order from the upstream side of the gas flow. The gas supply pipes 232a to 232g are made of metal materials such as SUS, for example.

[0029] like Figure 2As shown, the nozzles 249a to 249c are respectively arranged in a circular ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200 in a plan view, so as to stand upright from the lower part of the inner wall of the reaction tube 203 along the upper part toward the arrangement direction of the wafer 200. That is, the nozzles 249a to 249c are respectively arranged in a region that horizontally surrounds the wafer arrangement region on the side of the wafer arrangement region where the wafers 200 are arranged, and along the wafer arrangement region. In a plan view, the nozzle 249b is arranged so as to face the exhaust port 231a described later on a straight line with the center of the wafer 200 carried into the processing chamber 201 sandwiched therebetween. The nozzles 249a and 249c are arranged so as to sandwich a straight line L connecting the center of the nozzle 249b 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 connecting the nozzle 249b and the center of the wafer 200. That is, it can also be said that the nozzle 249c is arranged on the opposite side of the nozzle 249a with the straight line L sandwiched therebetween. The nozzles 249a 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 (face to face with) the exhaust port 231a in a plan view, and can supply gas to the wafer 200. A plurality of gas supply holes 250a to 250c are provided from the lower part to the upper part of the reaction tube 203.

[0030] A raw material of a film-forming agent is supplied from a gas supply pipe 232 a into the processing chamber 201 via an MFC 241 a , a valve 243 a , and a nozzle 249 a .

[0031] The first reactant as a film-forming agent is supplied from the gas supply pipe 232 b through the MFC 241 b , the valve 243 b , and the nozzle 249 b into the processing chamber 201 .

[0032] The second reactant as a film-forming agent is supplied from the gas supply pipe 232 c through the MFC 241 c , the valve 243 c , and the nozzle 249 c into the processing chamber 201 .

[0033] The etchant is supplied from the gas supply pipe 232 d into the processing chamber 201 via the MFC 241 d , the valve 243 d , the gas supply pipe 232 b , and the nozzle 249 b .

[0034] The inert gas is supplied from the gas supply pipes 232e to 232g through the MFCs 241e to 241g, valves 243e to 243g, gas supply pipes 232a to 232c, and nozzles 249a to 249c into the processing chamber 201. The inert gas functions as a purge gas, a carrier gas, a dilution gas, and the like.

[0035] The raw material supply system is mainly composed of the gas supply pipe 232a, MFC241a, and valve 243a. The first reactant supply system is mainly composed of the gas supply pipe 232b, MFC241b, and valve 243b. The second reactant supply system is mainly composed of the gas supply pipe 232c, MFC241c, and valve 243c. The etchant supply system (etchant exposure system) is mainly composed of the gas supply pipe 232d, MFC241d, and valve 243d. The inactive gas supply system is mainly composed of the gas supply pipes 232e to 232g, MFC241e to 241g, and valves 243e to 243g.

[0036] Any or all of the various supply systems described above may also be configured as an integrated supply system 248 formed by integrating valves 243a to 243g, MFCs 241a to 241g, etc. The integrated supply system 248 is configured such that the operation of connecting to each gas supply pipe 232a to 232g and supplying various gases into the gas supply pipe 232a to 232g, i.e., the opening and closing operation of the valves 243a to 243g, the flow rate adjustment operation by the MFCs 241a to 241g, etc., is controlled by the controller 121 described later. The integrated supply system 248 is configured in the form of an integrated unit of an integral type or a split type, and is configured such that the gas supply pipes 232a to 232g, etc., can be installed and removed as an integrated unit, and the integrated supply system 248 can be maintained, replaced, and added as an integrated unit.

[0037] 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 provided at a position opposite (face to face) to the nozzles 249a to 249c (gas supply holes 250a to 250c) sandwiching the wafer 200 in a plan view. The exhaust port 231a can be provided from the lower part of the side wall of the reaction tube 203 along the upper part, that is, along the wafer arrangement area. The exhaust port 231a is connected to the exhaust pipe 231. The exhaust pipe 231 is connected to the vacuum pump 246 as a vacuum exhaust device via the pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and the APC (Auto Pressure Controller, pressure automatic regulator) valve 244 as a pressure regulator (pressure regulating unit). The APC valve 244 is configured to open and close the valve in a state where the vacuum pump 246 is operated, so that the vacuum exhaust in the processing chamber 201 can be performed and the vacuum exhaust can be stopped. Furthermore, in a state where the vacuum pump 246 is operated, the pressure in the processing chamber 201 can be adjusted by adjusting the valve opening based on the pressure information detected by the pressure sensor 245. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 can also be included in the exhaust system.

[0038] Below the manifold 209, there is provided a sealing cap 219 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 and is formed into a disc shape. On the upper surface of the sealing cap 219, there is provided an O-ring 220b as a sealing member that abuts against the lower end of the manifold 209. Below the sealing cap 219, there is provided a rotating mechanism 267 for rotating the wafer box 217 described later. The rotating shaft 255 of the rotating mechanism 267 passes through 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 carries the wafer 200 in and out (transports) the wafer 200 in and out of the processing chamber 201 by raising and lowering the sealing cap 219 .

[0039] A baffle 219s is provided below the manifold 209 as a furnace cover, and when the sealing cap 219 is lowered and the wafer box 217 is carried out from the processing chamber 201, the lower end opening of the manifold 209 can be airtightly closed. The baffle 219s is made of a metal material such as SUS, and is formed in a disc shape. An O-ring 220c as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the baffle 219s. The opening and closing action (lifting action, rotation action, etc.) of the baffle 219s is controlled by the baffle opening and closing mechanism 115s.

[0040] The wafer box 217 as a substrate support is configured to support multiple (e.g., 25 to 200) wafers 200 in a horizontal position and in a mutually aligned state in a vertical direction in multiple stages, that is, arranged at intervals. The wafer box 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the wafer box 217, a heat insulation plate 218 made of a heat-resistant material such as quartz or SiC is supported in multiple stages.

[0041] A temperature sensor 263 as a temperature detector is provided in the reaction tube 203. By adjusting the power supply to 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.

[0042] 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. In addition, the controller 121 can be connected to an external storage device 123.

[0043] The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. In the storage device 121c, a control program for controlling the action of the substrate processing device, a process recipe that records the program and conditions of the substrate processing described later, etc., are recorded and stored in a readable form. The process recipe is composed in a manner that the controller 121 is used to enable the substrate processing device to execute the various programs of the substrate processing described later and to obtain a predetermined result, and functions as a program. Hereinafter, process recipes, control programs, etc. are also simply referred to as programs. In addition, process recipes are also simply referred to as recipes. When the term "program" is used in this specification, there are situations where only recipes are included, only control programs are included, or both are included. RAM121b is configured as a storage area (working area) for temporarily storing programs, data, etc. read by CPU121a.

[0044] The I / O interface 121d is connected to the above-mentioned MFC241a~241g, valves 243a~243g, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, wafer box elevator 115, shutter opening and closing mechanism 115s, etc.

[0045] 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 based on input of an operation command from the input / output device 122. The CPU 121a is configured to control, according to the contents of the read recipe, the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 241g, the opening and closing operation of the valves 243a to 243g, the opening and closing operation of the APC valve 244 and the pressure adjustment operation of 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.

[0046] The controller 121 can be constructed by installing the above-mentioned program recorded and 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, they are also simply collectively referred to as recording media. When the term "recording medium" is used in this specification, there are situations where only the storage device 121c is included alone, only the external storage device 123 is included alone, or both are included. It should be noted that providing a program to a computer can also be done without using the external storage device 123, but by using communication means such as the Internet and dedicated lines.

[0047] (2) Substrate processing steps

[0048] The substrate processing system (substrate processing device) is used as a process in the manufacturing process of a semiconductor device. Figure 4 , Figure 5 (a)~ Figure 5 (e) A method of processing a substrate, that is, an example of a processing sequence for forming an air gap on the substrate wafer 200 will be described. In the following description, the operation of each unit constituting the substrate processing apparatus is controlled by the controller 121.

[0049] It should be noted that the wafer 200 has a first film and a second film on the surface. Below, an example is described in which the first film is a film containing a semiconductor element and oxygen (first substrate), and the second film is a film containing a semiconductor element and nitrogen, or a metal element (second substrate). In addition, as a representative example, the first film is a silicon oxide film (SiO2 film, hereinafter also referred to as SiO film) containing silicon (Si) and oxygen (O) as semiconductor elements, and the second film is a silicon nitride film (Si3N4 film, hereinafter also referred to as SiN film) containing silicon (Si) and nitrogen (N) as semiconductor elements.

[0050] The processing sequence in this method is as follows:

[0051] (a) a step of forming a third film on the first film and the second film by supplying a raw material, a first reactant, and a second reactant to a wafer 200 having a first film and a second film on its surface, in the presence of a raw material alone, under the condition that the raw material does not undergo thermal decomposition and physical adsorption of the raw material occurs more predominantly than chemical adsorption (third film formation); and

[0052] (b) A step of removing the first film while maintaining the second film and the third film by exposing the surface of the wafer 200 having the third film formed on the first film and the second film to an etchant that reacts with the first film (etching).

[0053] It should be noted that in the processing sequence of this method, before the third film is formed, the following steps are performed: in the case of the raw material alone, under the condition that chemical adsorption or thermal decomposition is more dominant than physical adsorption of the raw material, the raw material, the first reactant or the second reactant are supplied to form an initial layer on the first film and the second film (initial layer formation). That is, in this method, the initial layer is formed on the first film and the second film, and the third film is formed on the initial layer. It should be noted that the initial layer formation can also be omitted depending on the materials of the first film and the second film. In the case of omitting the initial layer formation, the third film is directly formed on the first film and the second film.

[0054] In addition, in the processing sequence of this method, after etching, the following is performed:

[0055] (c) A step of forming a non-fluid film as a fourth film on the third film (fourth film formation).

[0056] These steps are performed in a non-plasma atmosphere.

[0057] It should be noted that the following are representative examples. Figure 4As shown, in the initial layer formation, the cycle including step A1 and step A2 is performed at the first temperature for a predetermined number of times (n1 times, n1 is an integer greater than 1 or 2) to explain the case, wherein step A1 is to supply a raw material to the wafer 200, and step A2 is to supply a first reactant or a second reactant to the wafer 200. In addition, Figure 4 The state in which the second reactant is supplied to the wafer 200 in step A2 is shown.

[0058] In addition, the following are representative examples: Figure 4 As shown, the following steps are performed in the third film formation.

[0059] A step (fluidity film formation) of forming a film having fluidity (hereinafter also referred to as fluidity film) on the initial layer by performing a cycle including step B1 and step B2 at a second temperature lower than the first temperature for a predetermined number of times (n2 times, n2 being an integer greater than 1 or 2), wherein step B1 is to supply a raw material and a first reactant to the wafer 200 at the same time, and step B2 is to supply a second reactant to the wafer 200; and

[0060] A step (post-processing) of thermally treating the wafer 200 after forming the fluidity film at a third temperature higher than the second temperature to modify the fluidity film into a film without fluidity (hereinafter also referred to as a non-fluidity film).

[0061] In this specification, post-processing is also referred to as PT.

[0062] In addition, the following are representative examples: Figure 4 As shown, in the fourth film formation, the following situation is described:

[0063] The cycle including step C1 and step C2 is performed a predetermined number of times (n3 times, n3 is an integer greater than 1 or 2) at a third temperature higher than the second temperature, wherein step C1 is to supply a raw material to the wafer 200, and step C2 is to supply a first reactant or a second reactant to the wafer 200. In addition, Figure 4 The state in which the second reactant is supplied to the wafer 200 in step C2 is shown.

[0064] In this manual, for convenience, Figure 4 The processing sequence shown is as follows. The same description is also used in the following description of the modified examples and other aspects.

[0065] Initial layer formation: (raw material → second reactant) × n1

[0066] Third film formation: (raw material + first reactant → second reactant) × n2 → PT

[0067] Fourth film formation: (raw material → second reactant) × n3

[0068] In addition, as shown below in the processing sequence, in the flowable film formation in the third film formation, the supply timing of the raw material, the first reactant, and the second reactant can be changed as appropriate.

[0069] Third film formation: (raw material → first reactant → second reactant) × n2 → PT

[0070] Third film formation: (raw material → first reactant → second reactant → first reactant) × n2 → PT

[0071] Third film formation: (raw material + first reactant → second reactant → first reactant) × n2 → PT

[0072] The term "wafer" used in this specification may mean the wafer itself or a laminate of a wafer and a predetermined layer, film, etc. formed on its surface. The term "wafer surface" used in this specification may mean the surface of the wafer itself or the surface of a predetermined layer formed on the wafer. When it is stated in this specification that "a predetermined layer is formed on the wafer", it may mean that the predetermined layer is directly formed on the surface of the wafer itself or that the predetermined layer is formed on a layer formed on the wafer. When the term "substrate" is used in this specification, it has the same meaning as when the term "wafer" is used.

[0073] The term "agent" used in this specification includes at least one of a gaseous substance and a liquid substance. A liquid substance includes a mist substance. That is, the film-forming agent (raw material, first reactant, second reactant) and the etching agent may each contain a gaseous substance, a liquid substance such as a mist substance, or both.

[0074] The term "layer" used in this specification includes at least one of a continuous layer and a discontinuous layer. The layer formed in each step described below may include a continuous layer, a discontinuous layer, or both.

[0075] (Wafer loading and wafer cassette loading)

[0076] After a plurality of wafers 200 are loaded into the wafer box 217 (wafer loading), the shutter 219s is moved by the shutter opening and closing mechanism 115s to open the lower end opening of the manifold 209 (shutter opening). Figure 1As 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 seals the lower end of the manifold 209 via the O-ring 220b. In this way, the wafers 200 are prepared in the processing chamber 201.

[0077] It should be noted that, on the surface of the wafer 200 loaded in the wafer box 217, that is, on the surface of the wafer 200 before the initial layer and the third film are formed, Figure 5 As shown in (a), the first film and the second film are adjacent to each other and alternately arranged. Here, the case where the first film and the second film are alternately arranged so that their surfaces are parallel to the flat surface of the wafer 200 is described. In addition, as described above, the case where the first film is a SiO film and the second film is a SiN film is described here.

[0078] (Pressure regulation and temperature regulation)

[0079] 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 regulated) 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 temperature. At this time, the power supply of the heater 207 is feedback controlled based on the temperature information detected by the temperature sensor 263 so that the desired temperature distribution (temperature regulation) is achieved in the processing chamber 201. In addition, the rotation mechanism 267 starts to rotate the wafer 200. 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.

[0080] (Initial layer formation)

[0081] The initial layer formation is performed by the following steps A1 and A2.

[0082] [Step A1]

[0083] In step A1 , a raw material is supplied to the wafer 200 in the processing chamber 201 .

[0084] Specifically, valve 243a is opened to allow the raw material to flow into the gas supply pipe 232a. The raw material is regulated in flow rate by MFC241a, supplied to the processing chamber 201 through nozzle 249a, and exhausted through exhaust port 231a. At this time, the raw material is supplied to the wafer 200 (raw material supply). At this time, valves 243e to 243g may also be opened to supply inactive gas to the processing chamber 201 through nozzles 249a to 249c, respectively.

[0085] After a predetermined time has passed, the valve 243a is closed to stop the supply of the raw material into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove the gaseous substances and the like remaining in the processing chamber 201 from the processing chamber 201. At this time, the valves 243e to 243g are opened to supply the inactive gas into the processing chamber 201 through the nozzles 249a to 249c. The inactive gas supplied by the nozzles 249a to 249c acts as a purge gas, thereby purging the space where the wafer 200 is present, that is, purging the processing chamber 201 (purge).

[0086] As a raw material, for example, a silane gas containing silicon (Si) can be used. As a silane gas, for example, a gas containing Si and a halogen, i.e., a halosilanes gas, can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. That is, the halosilanes gas includes chlorosilane gas, fluorosilane gas, bromosilane gas, iodosilane gas, etc. As a halosilanes gas, for example, a gas containing silicon, carbon (C) and a halogen, i.e., an organohalosilanes gas, can be used. As an organohalosilanes gas, for example, a gas containing Si, C and Cl, i.e., an organochlorosilane gas, can be used.

[0087] As raw materials, for example, silane-based gases that do not contain C and halogen, such as monosilane (SiH4) gas and disilane (Si2H6) gas; halosilane-based gases that do not contain C, such as dichlorosilane (SiH2Cl2) gas and hexachlorodisilane (Si2Cl6); alkylsilane-based gases such as trimethylsilane (SiH(CH3)3) gas, dimethylsilane (SiH2(CH3)2) gas, triethylsilane (SiH(C2H5)3) gas, and diethylsilane (SiH2(C2H5)2) gas; bis(trichlorosilyl)methane ((SiCl3)2CH2) gas, 1,2-dichlorosilane (SiH2Cl2) gas, and 1,2-dichlorosilane (SiH2Cl6) gas. Alkyl halosilane gases such as (trichlorosilyl)ethane ((SiCl3)2C2H4) gas; alkyl halosilane gases such as trimethylchlorosilane (SiCl(CH3)3) gas, dimethyldichlorosilane (SiCl2(CH3)2) gas, triethylchlorosilane (SiCl(C2H5)3) gas, diethyldichlorosilane (SiCl2(C2H5)2) gas, 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH3)2Si2Cl4) gas, and 1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH3)4Si2Cl2). In addition, as raw materials, alkylaminosilane-based gases such as (dimethylamino)trimethylsilane ((CH3)2NSi(CH3)3) gas, (diethylamino)triethylsilane ((C2H5)2NSi(C2H5)3) gas, (dimethylamino)triethylsilane ((CH3)2NSi(C2H5)3) gas, (diethylamino)trimethylsilane ((C2H5)2NSi(CH3)3) gas, (trimethylsilyl)amine ((CH3)3SiNH2) gas, (triethylsilyl)amine ((C2H5)3SiNH2) gas, (dimethylamino)silane ((CH3)2NSiH3) gas, and (diethylamino)silane ((C2H5)2NSiH3) gas can be used. As raw materials, one or more of these silicon-containing raw materials can be used.

[0088] It should be noted that some of these raw materials do not contain amino groups and contain halogens. In addition, some of these raw materials contain chemical bonds between silicon and silicon (Si-Si bonds). In addition, some of these raw materials contain silicon and halogens, or contain silicon, halogens and carbon. In addition, some of these raw materials contain alkyl groups and halogens. That is, some of these raw materials contain halogen groups and alkyl groups.

[0089] As the inert gas, rare gases such as nitrogen (N2) gas, argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas can be used. This is also the same in each step described later. As the inert gas, one or more of these can be used.

[0090] [Step A2]

[0091] In step A2 , the first reactant or the second reactant is supplied to the wafer 200 in the processing chamber 201 .

[0092] When the first reactant is supplied to the wafer 200, the valve 243b is opened to allow the first reactant to flow into the gas supply pipe 232b. The first reactant is regulated in flow rate by the MFC 241b, supplied to the processing chamber 201 via the nozzle 249b, and exhausted from the exhaust port 231a. At this time, the first reactant is supplied to the wafer 200 (first reactant supply). At this time, the valves 243e to 243g may also be opened to supply inactive gas to the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0093] In addition, in Figure 4 As shown, when the second reactant is supplied to the wafer 200, the valve 243c is opened and the second reactant flows into the gas supply pipe 232c. The second reactant is regulated in flow by the MFC 241c, supplied to the processing chamber 201 through the nozzle 249c, and exhausted by the exhaust port 231a. At this time, the second reactant is supplied to the wafer 200 (second reactant supply). At this time, the valves 243e to 243g can also be opened to supply inactive gas to the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0094] After a predetermined time has passed, valve 243b or 243c is closed to stop the supply of the first reactant or the second reactant into the processing chamber 201. Then, the gaseous substances remaining in the processing chamber 201 are exhausted from the processing chamber 201 by the same processing procedure as the purging in step A1.

[0095] As the first reactant and the second reactant, for example, a gas containing nitrogen (N) and hydrogen (H) can be used. In addition, the molecular structures of the first reactant and the second reactant may be the same or different. As the gas containing N and H, for example, ammonia (NH3) gas and other nitride-based gases; ethylamine-based gases such as monoethylamine (C2H5NH2) gas, diethylamine ((C2H5)2NH) gas, triethylamine ((C2H5)3N) gas; methylamine-based gases such as monomethylamine (CH3NH2) gas, dimethylamine ((CH3)2NH) gas, trimethylamine ((CH3)3N) gas; pyridine (C5H5N) gas, piperidine (C4H 10Cyclic amine gases such as monomethylhydrazine ((CH3)HN2H2) gas, dimethylhydrazine ((CH3)2N2H2) gas, trimethylhydrazine ((CH3)2N2(CH3)H) gas, and other organic hydrazine gases. It should be noted that since amine gases and organic hydrazine gases are composed of C, N, and H, these gases can also be referred to as C, N, and H-containing gases. The above-mentioned alkyl-containing amine gases can also be referred to as alkylamine gases. C-containing gases (containing C and H gases) such as ethylene (C2H4) gas, acetylene (C2H2) gas, propylene (C3H6) gas, and N-containing gases (containing N and H gases) such as NH3 gas can also be supplied simultaneously or non-simultaneously to replace the C, N, and H-containing gases. As either the first reactant or the second reactant, one or more of these N and H-containing reactants or C, N, and H-containing reactants can be used. It should be noted that the first reactant preferably contains an alkyl group, and more preferably contains an amine or an organic hydrazine.

[0096] [Scheduled number of implementations]

[0097] The cycle of performing the steps A1 and A2 non-simultaneously, i.e., performing the cycle of A1 and A2 non-simultaneously, is performed a predetermined number of times (n1 times, where n1 is an integer greater than 1 or 2). At this time, when the raw material exists alone, the cycle is performed a predetermined number of times under the condition that chemical adsorption or thermal decomposition of the raw material is more dominant than physical adsorption of the raw material.

[0098] As the processing conditions when the raw material is supplied in step A1, the following can be exemplified:

[0099] Treatment temperature (first temperature): 350 to 700°C, more preferably 450 to 650°C

[0100] Processing pressure: 1-2666Pa, preferably 67-1333Pa

[0101] Raw material supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm

[0102] Raw material supply time: 1 to 120 seconds, preferably 1 to 60 seconds

[0103] Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm, preferably 0.01 to 10 slm.

[0104] The description of a numerical range such as "350-700°C" in this specification means that the lower limit and the upper limit are included in the range. Therefore, for example, "350-700°C" means, "above 350°C and below 700°C". The same applies to other numerical ranges. In addition, the processing temperature in this specification refers to the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure refers to the pressure in the processing chamber 201. In addition, 0slm means the case where the gas is not supplied. These are also the same in the following descriptions.

[0105] As the treatment conditions when supplying the first reactant or the second reactant in step A2, the following can be exemplified:

[0106] Processing pressure: 1-4000 Pa, preferably 1-3000 Pa

[0107] First reactant or second reactant supply flow rate: 0.001 to 20 slm, preferably 1 to 10 slm

[0108] Supply time of the first reactant or the second reactant: 1 to 120 seconds, preferably 1 to 60 seconds.

[0109] The other processing conditions can be the same as those when the raw material is supplied in step A1.

[0110] By supplying the raw material in step A1 under the above-mentioned processing conditions, a part of the molecular structure of the molecules of the raw material can be adsorbed on the surface of the wafer 200, that is, the surface of the first film and the second film in step A1. In addition, by supplying the first reactant or the second reactant in step A2 under the above-mentioned processing conditions, a part of the molecular structure of the molecules of the raw material adsorbed on the surface of the first film and the second film can be reacted with the first reactant or the second reactant in step A2 to be modified to form a non-flowable layer (hereinafter also referred to as a non-flowable layer). Then, by performing the above-mentioned cycle a predetermined number of times under the above-mentioned processing conditions, as shown in FIG. Figure 5 As shown in (b), a non-fluid layer of a predetermined thickness can be formed on the first film and the second film as an initial layer. The initial layer becomes a continuous layer that conformally covers the surfaces of the first film and the second film.

[0111] The above cycle is preferably repeated multiple times. That is, the thickness of the non-fluidity layer formed in each cycle is preferably thinner than the desired thickness, and the above cycle is repeated multiple times until the thickness of the initial layer formed by stacking the non-fluidity layer reaches the desired thickness. It should be noted that the thickness of the initial layer is preferably set to be less than the thickness of the fluidity film described later, or thinner than the thickness of the fluidity film described later. The thickness of the initial layer is preferably set to a thickness of, for example, 0.2 nm or more and 5 nm or less, preferably 0.3 nm or more and 3 nm or less.

[0112] When the various raw materials and various reactants exemplified above are used, as the initial layer, for example, a Si and N-containing layer such as a silicon nitride layer (SiN layer), a Si, C and N-containing layer such as a silicon carbonitride layer (SiCN layer) can be formed. Since the various raw materials and various reactants mentioned above do not contain oxygen (O), the initial layer becomes a non-O-containing layer. In addition, the initial layer becomes a layer with lower hydrophilicity than the first film (O-containing film) on the surface of the wafer 200. In the case where the first film that becomes a part of the film formation base is a hydrophilic film, it is preferred that the initial layer be a non-hydrophilic layer (hydrophobic layer).

[0113] (Third Film Formation)

[0114] After the initial layers are formed on the first and second films, the third film is formed. The third film is formed by the following two steps, namely, flowable film formation and post-treatment.

[0115] [Flowable film formation]

[0116] When forming the fluid film, the output of the heater 207 is adjusted (temperature reduction) so that the temperature of the wafer 200 is changed to a second temperature lower than the first temperature. Then, when the temperature of the wafer 200 reaches the second temperature and is stable, the following steps B1 and B2 are performed.

[0117] [Step B1]

[0118] In step B1, a raw material and a first reactant are simultaneously supplied to the wafer 200 in the processing chamber 201. The same processing procedures as those described in steps A1 and A2 can be used for the processing procedures for supplying the raw material and the processing procedures for supplying the first reactant.

[0119] After a predetermined time, valves 243a and 243b are closed to stop supplying the raw material and the first reactant into the processing chamber 201. Then, the gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201 by the same processing procedure as the purging in step A1.

[0120] As the raw material, a predetermined raw material can be arbitrarily selected from the various raw materials exemplified in step A1. In addition, the raw material used in step B1 and the raw material used in step A1 may have the same or different molecular structures.

[0121] As the first reactant, a predetermined reactant can be arbitrarily selected from the various reactants exemplified in step A2. It should be noted that the molecular structures of the reactant used in step B1 and the reactant used in step A2 may be the same or different.

[0122] [Step B2]

[0123] In step B2, the second reactant is supplied to the wafer 200 in the processing chamber 201. The processing procedure when the second reactant is supplied can be the same as the processing procedure described in the above step A2.

[0124] After a predetermined time has passed, valve 243c is closed to stop supply of the second reactant into processing chamber 201. Then, gaseous substances and the like remaining in processing chamber 201 are exhausted from processing chamber 201 by the same processing procedure as the purging in step A1.

[0125] As the second reactant, a predetermined reactant can be arbitrarily selected from the various reactants exemplified in step A2. In addition, the reactant used in step B2 and the reactants used in steps A1 and B1 may have the same or different molecular structures.

[0126] [Scheduled number of implementations]

[0127] The cycle of performing the steps B1 and B2 non-simultaneously, i.e., performing the cycle of B1 and B2 non-simultaneously, is performed for a predetermined number of times (n1 times, where n1 is an integer greater than or equal to 1 or 2). At this time, when the raw material exists alone, the raw material is not thermally decomposed, and physical adsorption of the raw material is more dominant than chemical adsorption of the raw material, and the above cycle is performed for a predetermined number of times.

[0128] As the processing conditions when the raw material and the first reactant are supplied in step B1, the following can be exemplified:

[0129] Treatment temperature (second temperature): 0 to 150°C, preferably 10 to 100°C, more preferably 20 to 60°C

[0130] Processing pressure: 10-6000Pa, preferably 50-2000Pa

[0131] Raw material supply flow rate: 0.01~1slm

[0132] First reactant supply flow rate: 0.01~5slm

[0133] Raw material and first reactant supply time: 1 to 300 seconds

[0134] Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm, preferably 0.01 to 10 slm.

[0135] As the treatment conditions when supplying the second reactant in step B2, the following can be exemplified:

[0136] Second reactant supply flow rate: 0.01~5slm

[0137] Second reactant supply time: 1 to 300 seconds.

[0138] The other processing conditions can be the same as those when the raw material and the first reactant are supplied in step B1.

[0139] By performing the above-mentioned cycle a predetermined number of times under the above-mentioned treatment conditions, oligomers containing elements contained in at least any one of the raw materials, the first reactant, and the second reactant can be generated and grown on the first film and the second film, that is, on the initial layers formed on the first film and the second film, and made to flow, and a continuous oligomer-containing film as a fluid film is formed on the initial layer. It should be noted that oligomers refer to polymers with a relatively small number (for example, 10 to 100) of monomers (units) bonded and a relatively low molecular weight (for example, a molecular weight of less than 10,000). When the raw materials, the first reactant, and the second reactant exemplified above are used, the fluid film becomes, for example, a film containing various elements such as Si, Cl, and N, and composed of C such as CH3, C2H5, etc. x H 2x+1 (x is an integer of 1 to 3) a film of a substance represented by the chemical formula.

[0140] In addition, by carrying out a cycle including steps B1 and B2 under the above-mentioned processing conditions, the growth and flow of the oligomers formed on the first film and the second film can be promoted while the surface layer of the oligomers, the excess components contained in the oligomers, such as excess gas, impurities containing Cl, reaction by-products (hereinafter also referred to as by-products), etc. can be removed and discharged.

[0141] It should be noted that if the above-mentioned processing temperature is set to less than 0°C, the raw material supplied to the processing chamber 201 may be easily liquefied, and it may be difficult to supply the raw material to the wafer 200 in a gaseous state. At this time, the above-mentioned reaction of forming a fluid film may not be easy to proceed, and it may be difficult to form a fluid film on the initial layer. This problem can be solved by setting the processing temperature to above 0°C. This problem can be fully solved by setting the processing temperature to above 10°C, and this problem can be more fully solved by setting the processing temperature to above 20°C.

[0142] In addition, if the treatment temperature is set to a temperature higher than 150°C, the reaction of forming the fluid film may not be easy to proceed. In this case, the oligomer generated on the initial layer is more advantageous than the growth, and it may be difficult to form a fluid film on the initial layer. This problem can be solved by setting the treatment temperature to 150°C or less. This problem can be fully solved by setting the treatment temperature to 100°C or less, and this problem can be more fully solved by setting the treatment temperature to 60°C or less.

[0143] From these, the treatment temperature is preferably 0°C to 150°C, more preferably 10°C to 100°C, and still more preferably 20°C to 60°C.

[0144] [Post-processing]

[0145] After forming the flowable film on the first film and the second film, that is, on the initial layer formed on the first film and the second film, the output of the heater 207 is adjusted (temperature increase) so that the temperature of the wafer 200 is changed to a third temperature higher than the second temperature, preferably to a third temperature higher than the second temperature. Then, the post-processing (PT) is performed in a state where the temperature of the wafer 200 reaches the third temperature and is stable.

[0146] In PT, inert gas is supplied to the wafer 200 in the processing chamber 201. Specifically, valves 243e to 243g are opened to allow inert gas to flow into the gas supply pipes 232e to 232g. The inert gas is regulated in flow rate by MFCs 241e to 241g, supplied to the processing chamber 201 via nozzles 249a to 249c, and exhausted from the exhaust port 231a. At this time, inert gas is supplied to the wafer 200.

[0147] Examples of the treatment conditions for PT include:

[0148] Treatment temperature (third temperature): 100 to 1000°C, preferably 200 to 600°C

[0149] Processing pressure: 10-80000Pa, preferably 200-6000Pa

[0150] Inert gas supply flow rate (per gas supply pipe): 0.01~2slm

[0151] Inert gas supply time: 300 to 10,800 seconds.

[0152] By performing PT under the above-mentioned treatment conditions, the fluid film formed on the initial layer as a continuous oligomer-containing film can be modified. Thus, on the initial layer, a SiCN film or other Si, C and N-containing film, a SiN film or other Si and N-containing film can be formed as the third film. The third film becomes a continuous film that conformally covers the surface of the first film and the second film, and the surface of the initial layer to be formed on the first film and the second film. The third film is a fluid film at least during its formation, but changes to a non-fluid film by performing PT. It should be noted that in this specification, when using the term "third film", there are cases where the fluid film is changed to a non-fluid film by performing PT, cases where the fluid film is included before performing PT, or cases where both are included. The thickness of the third film formed by the fluid film formation and PT is, for example, preferably set to a thickness of 0.2 nm or more and 20 nm or less, preferably 0.5 nm or more and 10 nm or less.

[0153] It should be noted that by performing PT, the excess components contained in the fluid film can be discharged, and the third film can be appropriately densified. In addition, by setting the processing temperature (third temperature) of PT to a temperature higher than the processing temperature (first temperature) when the initial layer is formed, not only the fluid film can be modified, but also the initial layer as the base can be modified. That is, the excess components contained in the initial layer can be discharged, and the initial layer can be appropriately densified. As a result, the hardness of the third film and the initial layer can also be increased.

[0154] In PT, H-containing gas such as hydrogen (H2) gas may be supplied to the wafer 200, N-containing gas such as NH3 gas, i.e., gas containing N and H, may be supplied, and O-containing gas such as H2O gas, i.e., gas containing O and H, may be supplied. It should be noted that O2 gas may also be supplied as O-containing gas. That is, in PT, at least any one of N-containing gas, H-containing gas, N and H-containing gas, O-containing gas, and O and H-containing gas may be supplied to the wafer 200.

[0155] As the processing conditions when the H-containing gas is supplied in PT, the following can be exemplified:

[0156] H-containing gas supply flow rate: 0.01~3slm

[0157] Treatment pressure: 10 to 1000 Pa, preferably 200 to 800 Pa.

[0158] The other processing conditions can be the same as those in the case of performing PT in an inert gas atmosphere.

[0159] As the processing conditions when the gas containing N and H is supplied in PT, the following can be exemplified:

[0160] N and H containing gas supply flow rate: 10~10000sccm

[0161] Treatment pressure: 10 to 6000 Pa, preferably 200 to 2000 Pa.

[0162] The other processing conditions can be the same as those in the case of performing PT in an inert gas atmosphere.

[0163] As the processing conditions when supplying the O-containing gas in PT, the following can be exemplified:

[0164] O-containing gas supply flow rate: 10~10000sccm

[0165] Treatment pressure: 10 to 90,000 Pa, preferably 20,000 to 80,000 Pa.

[0166] The other processing conditions can be the same as those in the case of performing PT in an inert gas atmosphere.

[0167] It should be noted that, compared with the case of performing PT in an inert gas atmosphere, when PT is performed in a H-containing gas atmosphere or when PT is performed in a N- and H-containing gas atmosphere, the fluidity of the oligomer-containing layer can be improved, the impurity concentration of the third film can be reduced, the film density can be increased, and the etching resistance can be improved. It should be noted that, compared with the case of performing PT in a H-containing gas atmosphere, this effect can be improved when PT is performed in a N- and H-containing gas atmosphere.

[0168] Furthermore, when PT is performed in an O-containing gas atmosphere, O can be contained in the third film, and the film can be made into, for example, a silicon oxynitride film (SiON film) as a film containing Si, O, and N, or a silicon oxynitride carbide film (SiOCN film) as a film containing Si, O, C, and N. It should be noted that, in addition to this method, even if the wafer 200 having the third film formed on the surface is taken out of the processing chamber 201 and exposed to the atmosphere, O can be contained in the third film.

[0169] (Etching)

[0170] After forming the third film as a non-fluid film on the first film and the second film, that is, on the initial layer formed on the first film and the second film, the output of the heater 207 is adjusted (temperature reduction) so that the temperature of the wafer 200 is changed to a fourth temperature lower than the third temperature. Then, etching is performed in a state where the temperature of the wafer 200 reaches the fourth temperature and is stable.

[0171] During etching, the surface of the wafer 200 on which a third film is formed by an initial layer on the first film and the second film is exposed to an etchant that reacts with the first film. Specifically, the valve 243d is opened to allow the etchant to flow into the gas supply pipe 232d. The etchant is regulated in flow rate by the MFC241d, supplied to the processing chamber 201 via the nozzle 249b, and exhausted from the exhaust port 231a. At this time, the etchant is supplied to the wafer 200 on which a third film is formed by sandwiching an initial layer on the first film and the second film (etchant exposure). At this time, the valves 243e~243g can also be opened to supply inactive gas into the processing chamber 201 via the nozzles 249a~249c respectively.

[0172] After a predetermined time has passed, the valve 243d is closed to stop the supply of the etchant into the processing chamber 201. Then, the gas and the like remaining in the processing chamber 201 are exhausted from the processing chamber 201 by the same processing procedure as the purging in step A1.

[0173] As the etchant, it is preferable to use a substance whose reactivity with the first film is higher than each of its reactivity with the second film, its reactivity with the initial layer, and its reactivity with the third film.

[0174] As an etchant, for example, a fluorine (F)-containing gas can be used. As a F-containing gas, for example, chlorine trifluoride (ClF3) gas, chlorine fluoride (ClF) gas, nitrogen fluoride (NF3) gas, hydrogen fluoride (HF) gas, fluorine (F2) gas, etc. can be used. In addition, various cleaning solutions can also be used as an etchant. For example, as an etchant, an HF aqueous solution can also be used for DHF cleaning. In addition, for example, as an etchant, a cleaning solution containing ammonia water, hydrogen peroxide water and pure water can also be used to perform SC-1 cleaning (APM cleaning). In addition, for example, as an etchant, a cleaning solution containing hydrochloric acid, hydrogen peroxide water and pure water can also be used to perform SC-2 cleaning (HPM cleaning). In addition, for example, as an etchant, a cleaning solution containing sulfuric acid and hydrogen peroxide water can be used to perform SPM cleaning. As an etchant, one or more of these can be used.

[0175] As the processing conditions when the etchant is supplied during etching, the following can be exemplified:

[0176] Treatment temperature (fourth temperature): room temperature (25°C) to 300°C, preferably 50 to 150°C

[0177] Processing pressure: 1-13332 Pa, preferably 100-3990 Pa

[0178] Etching agent supply flow rate: 0.05 to 5 slm, preferably 0.1 to 2 slm

[0179] Etching agent supply time: 0.1 to 3 hours, preferably 0.1 to 1 hour

[0180] Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm, preferably 0.01 to 10 slm.

[0181] In addition, the etchant supply time and the etchant exposure time have the same meaning.

[0182] By exposing the surface of the wafer 200 to the etchant under the above-mentioned processing conditions, the etchant penetrates the third film, and then penetrates the initial layer to reach the first film and the second film. In the case where the second film is a SiN film containing nitrogen (N) or a film containing a metal element, the second film has a higher etching resistance than the first film. In addition, in the case where the initial layer or the third film is, for example, a SiCN film containing carbon (C) in the form of Si-C bonds or Si-CH3 bonds, or a SiN film containing nitrogen (N), the initial layer or the third film has a higher etching resistance than the first film. As a result, in this step, the first film can be selectively removed (etched) while the second film, the initial layer, and the third film are respectively maintained. By selectively removing the first film while the second film, the initial layer, and the third film are respectively maintained, it is possible to Figure 5As shown in (d), an air gap is formed on the wafer 200 with high precision as a closed space (gap) surrounded by the second film, the initial layer, the third film, etc. It should be noted that the amount of the first film removed, that is, the size of the air gap can be arbitrarily adjusted by appropriately selecting the etching processing conditions from the above-mentioned processing conditions. For example, by removing the entire first film from the surface of the wafer 200, the size of the air gap formed on the surface of the wafer 200 can be expanded to a desired size.

[0183] (Fourth Film Formation)

[0184] After the air gap is formed on the wafer 200, the fourth film is formed. When the fourth film is formed, the output of the heater 207 is adjusted (temperature increase) so that the temperature of the wafer 200 is changed to a fifth temperature higher than the fourth temperature. Then, in a state where the temperature of the wafer 200 reaches the fifth temperature and is stable, the following steps C1 and C2 are performed.

[0185] [Step C1]

[0186] In step C1, a raw material is supplied to the wafer 200 in the processing chamber 201. The processing procedure for supplying the raw material can be the same as the processing procedure described in the above step A1. As the raw material, a predetermined raw material can be arbitrarily selected from the various raw materials exemplified in step A1. It should be noted that the molecular structure of the raw material used in step C1 and the raw material used in step A1 may be the same or different.

[0187] [Step C2]

[0188] In step C2, the first reactant or the second reactant is supplied to the wafer 200 in the processing chamber 201. The processing procedure when supplying the first reactant or the second reactant can use the same processing procedure as the processing procedure described in the above step A2. As the first reactant or the second reactant, a predetermined reactant can be arbitrarily selected from the various reactants exemplified in step A2. It should be noted that the molecular structure of the reactant used in step C2 and the reactant used in step A2 may be the same or different.

[0189] [Scheduled number of implementations]

[0190] The cycle comprising the steps C1 and C2 is performed non-simultaneously, i.e., the cycle of C1 and C2 is performed non-simultaneously for a predetermined number of times (n3 times, where n3 is an integer greater than 1 or 2). At this time, when the raw material exists alone, the predetermined number of cycles are performed under the condition that chemical adsorption or thermal decomposition of the raw material is more dominant than physical adsorption of the raw material.

[0191] As the processing conditions when the raw material is supplied in step C1, the following can be exemplified:

[0192] Treatment temperature (fifth temperature): 350 to 700°C, preferably 450 to 650°C

[0193] Processing pressure: 1-2666Pa, preferably 67-1333Pa

[0194] Raw material supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm

[0195] Raw material supply time: 1 to 120 seconds, preferably 1 to 60 seconds

[0196] Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm, preferably 0.01 to 10 slm.

[0197] As the treatment conditions when supplying the first reactant or the second reactant in step C2, the following can be exemplified:

[0198] Processing pressure: 1-4000 Pa, preferably 1-3000 Pa

[0199] First reactant or second reactant supply flow rate: 0.001 to 20 slm, preferably 1 to 10 slm

[0200] Supply time of the first reactant or the second reactant: 1 to 120 seconds, preferably 1 to 60 seconds.

[0201] The other processing conditions can be the same as those when the raw material is supplied in step C1.

[0202] By supplying the raw material in step C1 under the above-mentioned treatment conditions, a part of the molecular structure of the molecules of the raw material can be adsorbed on the surface of the third film in step C1. In addition, by supplying the first reactant or the second reactant in step C2 under the above-mentioned treatment conditions, a part of the molecular structure of the molecules of the raw material adsorbed on the surface of the third film can react with the first reactant or the second reactant in step C2 to form a non-fluidity layer. Then, by performing the above-mentioned cycle a predetermined number of times under the above-mentioned treatment conditions, as Figure 5 As shown in (e), a film containing Si and N such as a SiN film or a film containing Si, C, and N such as a SiCN film can be formed as a fourth film on the third film. The fourth film is a non-flowable film.

[0203] The above cycle is preferably repeated multiple times. That is, the thickness of the non-fluidity layer formed in each cycle is preferably made thinner than a desired thickness, and the above cycle is repeated multiple times until the thickness of the fourth film formed by stacking the non-fluidity layers reaches a desired thickness.

[0204] It should be noted that in step C2, as the first reactant or the second reactant, an O-containing gas such as H2O gas or O2 gas may be supplied to replace the various reactants (gases containing N and H) exemplified in step A2, or the above-mentioned O-containing gas may be further added to the various reactants exemplified in step A2 and supplied. In these cases, a silicon oxide film (SiO film), a silicon oxycarbide film (SiOC film), a silicon oxycarbonitride film (SiOCN film), or a silicon oxynitride film (SiON film) may be formed as the fourth film. In addition, in the formation of the fourth film, step C2 of supplying the first reactant or the second reactant may not be performed. In this case, a silicon film (Si film) may be formed as the fourth film.

[0205] (Post-Purge and Atmospheric Pressure Restoration)

[0206] After the fourth film formation is completed, an inert 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 and reaction by-products 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 inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure recovery).

[0207] (Cassette unloading and wafer release)

[0208] Then, the sealing cap 219 is lowered by the wafer box elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafer 200 is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported by the wafer box 217 (wafer box unloading). After the wafer box is unloaded, the baffle 219s is moved, and the lower end opening of the manifold 209 is sealed by the baffle 219s via the O-ring 220c (closing 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).

[0209] (3) Effects of this method

[0210] According to this aspect, one or more of the following effects can be obtained.

[0211] (a) By performing the above-mentioned initial layer formation, the above-mentioned third film formation, and etching on the wafer 200 having the first film and the second film on the surface, it is possible to suppress the etching of the second film, the initial layer, and the third film while highly selectively etching the first film. Thus, it is possible to form an air gap on the surface of the wafer 200 with high precision and accuracy. It should be noted that, as described above, the initial layer formation may be omitted. In the case where the initial layer formation is omitted, by performing the above-mentioned third film formation and etching on the wafer 200 having the first film and the second film on the surface, it is possible to suppress the etching of the second film and the third film while highly selectively etching the first film. Thus, it is possible to form an air gap on the surface of the wafer 200 with high precision and accuracy.

[0212] (b) In the formation of the third film, a continuous film can be formed while the third film can be effectively permeable to the etchant. As a result, it is not necessary to perform third film processing such as providing a flow port (opening) in the third film for allowing the etchant to flow downward, and the etchant can be brought into contact with the first film. That is, when forming an air gap, the complicated steps that were previously necessary can be omitted, the process can be simplified, and the air gap can be efficiently formed. As a result, the total processing time can be shortened, and productivity can be greatly improved.

[0213] (c) By using as an etchant a substance having a higher reactivity with the first film than with the second film, the initial layer, and the third film, the etching of the second film, the initial layer, and the third film by the etchant can be suppressed while the etching of the first film by the etchant can be promoted, and the first film can be effectively removed selectively from among the first film, the second film, the initial layer, and the third film. It should be noted that, as described above, the formation of the initial layer can be omitted. In the case where the formation of the initial layer is omitted, by using as an etchant a substance having a higher reactivity with the first film than with the second film and the third film, the etching of the first film by the etchant can be suppressed while the etching of the second film and the third film by the etchant can be promoted, and the first film can be effectively removed selectively from among the first film, the second film, the initial layer, and the third film.

[0214] (d) By sequentially performing the initial layer formation and the third film formation, before forming the fluid film on the first film and the second film, the initial layer without fluidity is formed at a higher temperature than when the fluid film is formed, thereby preventing the film forming process from affecting the surface state of the substrate. Thus, the abnormal growth of the fluid film on the first film and the second film and the occurrence of film formation defects can be suppressed, and a conformal and continuous third film can be appropriately formed.

[0215] It should be noted that the above-mentioned abnormal growth means that, for example, the film to be formed on the wafer 200 is affected by the surface state of the first film that becomes a part of the base for film forming processing, that is, the OH (hydroxyl) terminal on the surface of the O-containing film, and grows into a so-called droplet shape (island shape) or the like. The abnormal growth may reduce the uniformity of the film thickness within the wafer surface of the film to be formed on the wafer 200. In addition, the abnormal growth may deteriorate the surface roughness (flatness) of the film to be formed on the wafer 200. In addition, the abnormal growth may become a cause of particle generation in the processing chamber 201.

[0216] (e) By forming the fourth film after etching, the fourth film having a higher density than the third film can be stacked on the third film, and the third film having a lower density can be reinforced by the fourth film having a higher density. Thus, the strength of the stacked film of the third film and the fourth film can be improved as a whole.

[0217] (f) By arranging the first film and the second film adjacent to each other and alternately on the surface of the wafer 200 before forming the third film, a plurality of air gaps can be formed adjacent to each other precisely.

[0218] (g) When the raw material contains silicon, the first reactant contains nitrogen and hydrogen, the second reactant contains nitrogen and hydrogen, and the second reactant and the first reactant have different molecular structures, the above effect can be more significantly obtained and the accuracy of forming the air gap can be further improved.

[0219] (h) When at least one of the raw material and the first reactant contains an alkyl group, etching of the third film by the etchant can be more effectively suppressed, and the accuracy of forming the air gap can be further improved.

[0220] (i) When the raw material contains a halogen group and an alkyl group, and the first reactant contains an alkyl group, etching of the third film by the etchant can be more effectively suppressed, and the accuracy of forming the air gap can be further improved.

[0221] (j) When the raw material is alkylhalosilane, the first reactant is amine or organic hydrazine, and the second reactant is hydrogen nitride, etching of the third film by the etchant can be more effectively suppressed, and the accuracy of forming the air gap can be further improved.

[0222] (k) When the first film contains a semiconductor element and oxygen, selective etching of the first film by the etchant can be further promoted, and the accuracy of forming the air gap can be further improved.

[0223] (1) When the second film contains a semiconductor element and nitrogen, or contains a metal element, etching of the second film by an etchant can be more effectively suppressed, and the accuracy of forming the air gap can be further improved.

[0224] (m) When the third film contains a semiconductor element, carbon, and nitrogen, etching of the third film by an etchant can be more effectively suppressed, and the accuracy of forming the air gap can be further improved.

[0225] (n) When the etchant contains fluorine and hydrogen, the first film can be etched with high selectivity while suppressing the etching of the second film and the third film, and the formation accuracy of the air gap can be further improved. It should be noted that the etchant can be a gaseous substance, a liquid substance, or a substance containing both. The etchant can also be, for example, an aqueous solution containing fluorine and hydrogen. When the etchant is an aqueous solution, the first film can be etched at a high etching rate, without residue, and with high selectivity.

[0226] (o) The initial layer formation, the third film formation, the etching, and the fourth film formation can be performed in a non-plasma atmosphere, and plasma damage to the wafer 200 and the like can be prevented.

[0227] (p) The above-mentioned effects can be similarly obtained even when a predetermined substance (gaseous substance, liquid substance) is arbitrarily selected from the above-mentioned various raw materials, various reactants, various etchants, and various inert gases and used.

[0228] <Other aspects of the present disclosure>

[0229] Various aspects of the present disclosure have been specifically described above, but the present disclosure is not limited to the above aspects, and various modifications can be made without departing from the gist of the present disclosure.

[0230] For example, in the above-mentioned method, the first film and the second film are alternately arranged so that their surfaces are parallel to the flat surface of the wafer. However, the present disclosure is not limited to such a method. Figure 6 As shown in (a), a wafer having a plurality of recessed portions such as grooves formed at predetermined intervals on the surface and a first film formed to fill each recessed portion and a second film formed outside the recessed portion arranged alternately can be used as a substrate to be processed.

[0231] In this embodiment, the initial layer can be formed by performing the processing procedure and processing conditions described in the above embodiment, so that Figure 6 As shown in (b), a non-fluid initial layer can be formed on the first film and the second film. In addition, by forming a third film under the processing procedure and processing conditions described in the above method, as shown in Figure 6 As shown in (c), a third film as a continuous non-fluid film can be formed on the first film and the second film, that is, on the initial layer formed on the first film and the second film. In addition, by etching in the processing procedure and processing conditions described in the above method, the first film is selectively removed while the second film, the initial layer and the third film are maintained, as shown in FIG. Figure 6As shown in (d), air gaps can be formed on the surface of the wafer 200 with high accuracy and precision. In addition, by forming the fourth film under the processing procedure and processing conditions described in the above-mentioned embodiment, as shown in FIG. Figure 6 As shown in (e), a fourth film having a high density can be formed on a third film having a low density.

[0232] In this method, the same effect as in the above method can be obtained. In this method, the amount of the first film removed, that is, the size of the air gap can be arbitrarily adjusted by appropriately selecting the etching processing conditions from the above processing condition range. For example, the entire first film can be removed from the concave portion formed on the wafer surface, or Figure 6 As shown in (d), a portion of the first film may remain in a recess formed on the wafer surface.

[0233] In addition, for example, in the above-mentioned method, an example of performing initial layer formation before the third film is formed is described. However, the present disclosure is not limited to this method, and the initial layer formation may not be performed before the third film is formed. In addition, a treatment (hydrophobic treatment) for hydrophobizing the surfaces of the first film and the second film may be performed to replace the initial layer formation. As a treatment, plasma treatment, annealing treatment, nitridation treatment (plasma nitridation treatment, thermal nitridation treatment), etc. may be performed. Thus, the surfaces of the first film and the second film can be made non-hydrophilic (hydrophobic) without performing initial layer formation. In addition, in the above-mentioned method, an example of performing PT after the fluidity film is formed is described. However, the present disclosure is not limited to this method, and PT may not be performed after the fluidity film is formed. In addition, in the above-mentioned method, an example of performing a fourth film formation after etching is described. However, the present disclosure is not limited to this method, and the fourth film formation may not be performed after etching. These methods can achieve the same effect as the above-mentioned method.

[0234] In addition, for example, in the above-mentioned method, an example of etching after the third film is formed is described. However, the present disclosure is not limited to this method. The third film formed on the substrate may also be heat-treated at a temperature in the range of 400 to 600° C. after the third film is formed and before etching. In this way, the hardness of the third film can be further improved. It should be noted that the heat treatment can be performed under the same processing procedure and processing conditions as PT.

[0235] In addition, for example, in the above-mentioned method, an example is described in which a series of steps from the initial layer formation to the fourth film formation are performed in the same processing chamber 201 (in-situ) of the substrate processing system. However, the present disclosure is not limited to this method. For example, in a series of processes, specific steps, such as PT, etching, etc., can also be performed in other processing chambers (ex-situ) of the substrate processing system. For example, a substrate processing system containing a plurality of separate substrate processing devices (a first substrate processing device, a second substrate processing device, a third substrate processing device, etc.) can also be used to perform each step in different processing chambers of different substrate processing devices, that is, in different processing units. In addition, for example, a substrate processing system containing a cluster-type substrate processing device in which a plurality of processing chambers (a first processing chamber, a second processing chamber, a third processing chamber, etc.) are arranged around a transfer chamber can also be used to perform each step in different processing chambers of the same substrate processing device, that is, in different processing units. These situations can also obtain the same effect as the above-mentioned method.

[0236] In addition, for example, in the above-mentioned method, the case where the second film is a film containing a semiconductor element and nitrogen is cited as a main example for explanation. However, the present disclosure is not limited to this method. For example, the second film may also be a film containing metal elements such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), tantalum (Ta), molybdenum (Mo), copper (Cu), cobalt (Co), tungsten (W), and ruthenium (Ru), and the same effect as the above-mentioned method can be obtained.

[0237] In addition, for example, in the above-mentioned method, the case where the third film is a SiN film or a SiCN film is cited as a main example for explanation. However, the present disclosure is not limited to this method. For example, the third film may also be a film containing semiconductor elements such as a SiOC film, a SiOCN film, a SiON film, or a Si film, and the same effect as the above-mentioned method can be obtained.

[0238] In addition, for example, in the above-mentioned method, the case where the fourth film is a SiN film or a SiCN film is cited as a main example for explanation. However, the present disclosure is not limited to this method. For example, the fourth film may also be a film containing semiconductor elements such as a SiO film, a SiOC film, a SiOCN film, a SiON film, or a Si film, and the same effect as the above-mentioned method can be obtained.

[0239] The recipes used in each process are preferably prepared separately according to the process content, and are pre-recorded and stored in the storage device 121c via the communication circuit and the external storage device 123. Moreover, it is preferred that when each process is started, the CPU 121a appropriately selects a suitable recipe from the multiple recipes recorded and stored in the storage device 121c according to the process content. Thus, a film of various 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, and various processes can be started quickly by avoiding operational errors.

[0240] The above recipe is not limited to the case of newly making, for example, it can be prepared by changing an existing recipe already installed in the substrate processing device. When changing the process recipe, the changed recipe can be installed in the substrate processing device via a communication circuit and a recording medium recording the recipe. In addition, the input and 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.

[0241] 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 for example, it can also be appropriately 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 having a hot wall type processing furnace is described. The present disclosure is not limited to the above-mentioned method, and it can also be appropriately applied when a film is formed using a substrate processing device having a cold wall type processing furnace.

[0242] When these substrate processing apparatuses are used, each process can be performed according to the same processing procedures 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.

[0243] The above-mentioned aspects and modifications may be used in combination as appropriate. The processing procedures and processing conditions in this case may be, for example, the same as the processing steps and processing conditions in the above-mentioned aspects and modifications.

[0244] [Example]

[0245] Through the processing sequence in the above manner, air gaps are formed on the surface of the substrate, and a TEM image of the wafer surface during the formation process is taken.

[0246] Specifically, a substrate to be processed has a surface on which a plurality of recesses are formed, and a first film (1 st film), and a second film (2 nd Si wafers in which two layers of film are arranged adjacent to each other and alternately. Figure 7(a) shows a TEM image of the wafer surface in Example.

[0247] The wafer is subjected to the same processing procedure and processing conditions as those for the initial layer formation and the third film formation in the above-mentioned manner, and an initial layer and a third film (3 rd film). Figure 7 (b) shows a TEM image of the wafer surface in Example after the third film is formed. As shown in this TEM image, it can be seen that the third film is continuously formed on the first film and the second film.

[0248] Next, etching is performed by exposing the wafer surface on which the third film is formed to an etchant. The etching is performed using the same processing procedure and processing conditions as the etching in the above embodiment. Figure 7 (c)~ Figure 7 (e) TEM images of the wafer surface of the embodiment after etching are sequentially shown when the etching agent exposure time is set to 30 minutes, 60 minutes, and 90 minutes. It can be seen from these images that by etching, the first film can be selectively removed while the second film and the third film are maintained, and an air gap (AirGap) can be formed on the wafer with high precision. In addition, it can also be seen that by appropriately selecting the etching processing conditions (exposure time) from the range of etching processing conditions in the above manner, the removal amount of the first film, that is, the size of the air gap, can be arbitrarily controlled.

[0249] Next, the fourth film (4 th film). Figure 7 (f) and Figure 7 (g) shows a TEM image of the wafer surface of an embodiment in which the etching is performed by setting the exposure time of the etchant to 25 minutes, and a fourth film is formed on the third film after forming an air gap. Figure 7 (f) Figure 7 (g) Partially enlarged TEM image As can be seen from these TEM images, a large number of air gaps can be formed on the wafer with high accuracy and precision.

[0250] Explanation of symbols

[0251] 200 Wafer (substrate)

Claims

1. A substrate processing method, comprising: (a) a process of forming a third film on a substrate having a first film and a second film on its surface by supplying a raw material, a first reactant, and a second reactant in the presence of a raw material alone, under conditions where the raw material does not undergo thermal decomposition and physical adsorption of the raw material is more dominant than chemical adsorption, thereby supplying the raw material; and (b) A step of removing the first film while maintaining the second film and the third film by exposing the surface of the substrate having the third film formed on the first film and the second film to an etchant that reacts with the first film.

2. The substrate processing method according to claim 1, wherein: In (a), an oligomer containing an element contained in at least any one of the raw material, the first reactant, and the second reactant is made to flow on the first film and the second film to form the third film.

3. The substrate processing method according to claim 1, wherein: The reactivity of the etchant with the first film is higher than each of the reactivity of the etchant with the second film and the reactivity of the etchant with the third film.

4. The substrate processing method according to claim 1, wherein: In (a), before forming the third film, in the presence of the raw material alone, the raw material and the first reactant or the second reactant are supplied under conditions where chemical adsorption or thermal decomposition of the raw material occurs more advantageously than physical adsorption, thereby forming an initial layer on the first film and the second film, and forming the third film on the initial layer.

5. The substrate processing method according to claim 4, wherein: The initial layer is a non-fluid layer, and the third film is a fluid film at least during its formation process.

6. The substrate processing method according to claim 2, wherein: After performing step (b), the method further comprises: (c) forming a non-fluid film as a fourth film on the third film.

7. The substrate processing method according to claim 1, wherein: On the surface of the substrate before the third film is formed, the first film and the second film are adjacently and alternately arranged.

8. The substrate processing method according to any one of claims 1 to 7, wherein: The raw material contains silicon, the first reactant contains nitrogen and hydrogen, the second reactant contains nitrogen and hydrogen, and the molecular structure of the second reactant is different from that of the first reactant.

9. The substrate processing method according to any one of claims 1 to 7, wherein: At least one of the raw material and the first reactant contains an alkyl group.

10. The substrate processing method according to any one of claims 1 to 7, wherein: The raw material contains a halogen group and an alkyl group, and the first reactant contains an alkyl group.

11. The substrate processing method according to any one of claims 1 to 7, wherein: The raw material is alkyl halosilane, the first reactant is amine or organic hydrazine, and the second reactant is hydrogen nitride.

12. The substrate processing method according to any one of claims 1 to 7, wherein: The first film contains a semiconductor element and oxygen.

13. The substrate processing method according to any one of claims 1 to 7, wherein: The second film contains a semiconductor element and nitrogen, or contains a metal element.

14. The substrate processing method according to any one of claims 1 to 7, wherein: The third film contains a semiconductor element, carbon, and nitrogen.

15. The substrate processing method according to any one of claims 1 to 7, wherein: The third film exposed to the etchant in (b) is a continuous film.

16. The substrate processing method according to any one of claims 1 to 7, wherein: The etchant contains fluorine and hydrogen.

17. The substrate processing method according to any one of claims 1 to 7, wherein: (a) and (b) were performed in a non-plasma atmosphere.

18. A method for manufacturing a semiconductor device, comprising: (a) a process of forming a third film on a substrate having a first film and a second film on its surface by supplying a raw material, a first reactant, and a second reactant in the presence of a raw material alone, under conditions where the raw material does not undergo thermal decomposition and physical adsorption of the raw material is more dominant than chemical adsorption, thereby supplying the raw material; and (b) A step of removing the first film while maintaining the second film and the third film by exposing the surface of the substrate having the third film formed on the first film and the second film to an etchant that reacts with the first film.

19. A substrate processing system, which is a substrate processing system for processing a substrate, comprising: a raw material supply system for supplying raw materials to the substrate; a first reactant supply system for supplying a first reactant to the substrate; a second reactant supply system for supplying a second reactant to the substrate; an etchant exposure system for exposing the substrate to the etchant; a heater for heating the substrate; as well as The control unit is configured to control the raw material supply system, the first reactant supply system, the second reactant supply system, the etchant exposure system, and the heater to perform the following processing: (a) a process for forming a third film on a substrate having a first film and a second film on a surface thereof, by supplying the raw material, the first reactant and the second reactant in the presence of a raw material alone, under the condition that the raw material does not undergo thermal decomposition and physical adsorption of the raw material is more dominant than chemical adsorption, to the substrate; as well as (b) A process of removing the first film while maintaining the second film and the third film by exposing the surface of the substrate having the third film formed on the first film and the second film to the etchant that reacts with the first film.

20. A program that causes a substrate processing apparatus to execute the following process through a computer: (a) a process of forming a third film on a substrate having a first film and a second film on a surface thereof, by supplying a raw material, a first reactant, and a second reactant in the presence of a raw material alone, under conditions where the raw material does not undergo thermal decomposition and physical adsorption of the raw material is more dominant than chemical adsorption, thereby supplying the first film and the second film; and (b) A process of removing the first film while maintaining the second film and the third film by exposing the surface of the substrate having the third film formed on the first film and the second film to an etchant that reacts with the first film.

Images