Substrate processing method, method for manufacturing a semiconductor device, substrate processing apparatus, and program

Abstract

A technology of the present invention involves performing: (a) a step for supplying a first film-forming agent on a substrate having a recess provided on the surface thereof, to form a first film in the recess; (b) a step for supplying a second film-forming agent to the substrate to form, on the first film formed in the recess, a second film having a chemical composition different from that of the first film; (c) a step for supplying a modifying agent containing fluorine on the substrate to modify a portion of the second film; and (d) a step for supplying an etching agent containing a halogen to the substrate to remove the modified portion of the second film.

Description

Technical Field

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

Background Art

[0002] As one step in the manufacturing process of a semiconductor device, a step of supplying a raw material to a substrate having recesses such as trenches and holes provided on its surface and forming a film in the recesses may be performed (see, for example, International Publication No. 2019 / 003662).

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present disclosure is to provide a technique capable of forming a film with high accuracy in a recess provided on the surface of a substrate.

Means for Solving the Problems

[0004] According to one aspect of the present disclosure, (a) a step of forming a first film in the recess by supplying a first film-forming agent to a substrate having a recess on its surface; (b) a step of forming a second film having a chemical composition different from that of the first film on the first film formed in the recess by supplying a second film-forming agent to the substrate; (c) a step of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; (d) a step of removing the modified part of the second film by supplying an etching agent containing a halogen to the substrate; A technique for performing the above is provided.

Advantages of the Invention

[0005] According to the present disclosure, it becomes possible to form a film with high accuracy in a recess provided on the surface of a substrate.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0007] <One aspect of the present disclosure> Hereinafter, one aspect of the present disclosure will be mainly described with reference to FIGS. 1 to 3, FIG. 4, and FIGS. 5(a) to 5(e). Note that the drawings used in the following description are all schematic, and the dimensional relationships of the respective elements shown in the drawings, the ratios of the respective elements, etc. do not necessarily match the actual ones. Also, the dimensional relationships of the respective elements and the ratios of the respective elements do not necessarily match even between a plurality of drawings.

[0008] (1) Configuration of the substrate processing apparatus As shown in FIG. 1, the processing furnace 202 has a heater 207 as a temperature adjuster (heating unit). The heater 207 has a cylindrical shape and is vertically installed by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) for activating (exciting) the gas with heat.

[0009] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and is formed in a cylindrical shape with the upper end closed and the lower end open. 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 in a cylindrical shape with the upper and lower ends open. The upper end portion of the manifold 209 is engaged with the lower end portion of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a as a seal member is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 is vertically installed in the same manner as the heater 207. Mainly, the reaction tube 203 and the manifold 209 constitute a processing container (reaction container). A processing chamber 201 is formed in the cylindrical hollow portion of the processing container. The processing chamber 201 is configured to be able to accommodate a wafer 200 as a substrate. Processing of the wafer 200 is performed in this processing chamber 201.

[0010] Inside the processing chamber 201, nozzles 249a to 249c as the first to third supply units are respectively provided so as to penetrate the side wall of the manifold 209. The nozzles 249a to 249c are also respectively referred to as the first to third nozzles. The nozzles 249a to 249c are made of a heat-resistant material such as quartz or SiC, for example. Gas supply pipes 232a to 232c are respectively connected to the nozzles 249a to 249c. The nozzles 249a to 249c are different nozzles, and each of the nozzles 249a and 249c is provided adjacent to the nozzle 249b.

[0011] In the gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c, which are flow rate controllers (flow rate control units), and valves 243a to 243c, which are on-off valves, are respectively provided in order from the upstream side of the gas flow. Downstream of the valve 243a of the gas supply pipe 232a, gas supply pipes 232d and 232f are respectively connected. Downstream of the valve 243b of the gas supply pipe 232b, gas supply pipes 232e and 232g are respectively connected. Downstream of the valve 243c of the gas supply pipe 232c, a gas supply pipe 232h is connected. In the gas supply pipes 232d to 232h, MFCs 241d to 241h and valves 243d to 243h are respectively provided in order from the upstream side of the gas flow. The gas supply pipes 232a to 232h are made of a metal material such as SUS, for example.

[0012] As shown in FIG. 2, the nozzles 249a to 249c are each provided in an annular space between the inner wall of the reaction tube 203 and the wafer 200 in a plan view, along the upper part from the lower part of the inner wall of the reaction tube 203, so as to rise upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249c are each provided in a region on the side of the wafer arrangement region where the wafers 200 are arranged, in a region horizontally surrounding the wafer arrangement region, along the wafer arrangement region. In a plan view, the nozzle 249b is arranged so as to face the exhaust port 231a (to be described later) in a straight line across the center of the wafer 200 carried into the processing chamber 201. The nozzles 249a and 249c are arranged so as to sandwich the straight line L passing through the centers of the nozzle 249b and the exhaust port 231a from both sides along the inner wall of the reaction tube 203 (the outer peripheral portion of the wafer 200). The straight line L is also a straight line passing through the nozzle 249b and the center of the wafer 200. That is, it can also be said that the nozzle 249c is provided on the side opposite to the nozzle 249a with the straight line L interposed therebetween. The nozzles 249a and 249c are arranged symmetrically with the straight line L as the axis of symmetry. Gas supply holes 250a to 250c for supplying gas are respectively provided on the side surfaces of the nozzles 249a to 249c. The gas supply holes 250a to 250c are each opened so as to face (opposite) the exhaust port 231a in a plan view, and it is possible to supply gas toward 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.

[0013] From the gas supply pipe 232a, a raw material (raw material gas) is supplied into the processing chamber 201 through the MFC241a, the valve 243a, and the nozzle 249a. The raw material is used as one of the first film-forming agents, also used as one of the second film-forming agents, and also used as one of the third film-forming agents. When the raw material is used as the first film-forming agent, the second film-forming agent, and the third film-forming agent, they can also be referred to as the first raw material (first raw material gas), the second raw material (second raw material gas), and the third raw material (third raw material gas), respectively.

[0014] From the gas supply pipe 232b, the first reactant (first reaction gas) is supplied into the processing chamber 201 via the MFC 241b, valve 243b, and nozzle 249b. The first reactant is used as one of the first film-forming agents.

[0015] From the gas supply pipe 232c, the second reactant (second reaction gas) is supplied into the processing chamber 201 via the MFC 241c, valve 243c, and nozzle 249c. The second reactant is used as one of the second film-forming agents and also as one of the third film-forming agents. When the second reactant is used as the second and third film-forming agents, they can also be referred to as the second reactant (second reaction gas) and the third reactant (third reaction gas), respectively.

[0016] From the gas supply pipe 232d, the modifier (modifying gas) is supplied into the processing chamber 201 via the MFC 241d, valve 243d, gas supply pipe 232a, and nozzle 249a.

[0017] From the gas supply pipe 232e, the etchant (etching gas) is supplied into the processing chamber 201 via the MFC 241e, valve 243e, and nozzle 249b.

[0018] From the gas supply pipes 232f to 232h, the inert gas is supplied into the processing chamber 201 via the MFCs 241f to 241h, valves 243f to 243h, gas supply pipes 232a to 232c, and nozzles 249a to 249c, respectively. The inert gas acts as a purge gas, carrier gas, dilution gas, etc.

[0019] Primarily, the raw material supply system (raw material gas supply system) is constituted by the gas supply pipe 232a, MFC 241a, and valve 243a. Primarily, the first reactant supply system (first reaction gas supply system) is constituted by the gas supply pipe 232b, MFC 241b, and valve 243b. Primarily, the second reactant supply system (second reaction gas supply system) is constituted by the gas supply pipe 232c, MFC 241c, and valve 243c. Primarily, the reformer supply system (reformed gas supply system) is constituted by the gas supply pipe 232d, MFC 241d, and valve 243d. Primarily, the etchant supply system (etching gas supply system) is constituted by the gas supply pipe 232e, MFC 241e, and valve 243e. Primarily, the inert gas supply system is constituted by the gas supply pipes 232f to 232h, MFCs 241f to 241h, and valves 243f to 243h.

[0020] Each or all of the raw material supply system and the first reactant supply system are also referred to as the first film-forming agent supply system. Each or all of the raw material supply system and the second reactant supply system are also referred to as the second film-forming agent supply system and also as the third film-forming agent supply system.

[0021] Among the various supply systems described above, any one or all of the supply systems may be configured as an integrated supply system 248 in which valves 243a to 243h, MFCs 241a to 241h, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232h, and the supply operations of various substances (various gases) into the gas supply pipes 232a to 232h, that is, the opening and closing operations of the valves 243a to 243h and the flow rate adjustment operations by the MFCs 241a to 241h, etc. are configured to be controlled by a controller 121 described later. The integrated supply system 248 is configured as an integrated unit of an integral type or a split type, and can be attached and detached in units of the integrated unit to the gas supply pipes 232a to 232h, etc., and maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed in units of the integrated unit.

[0022] Below the lower sidewall of the reaction tube 203, an exhaust port 231a for exhausting the atmosphere in the processing chamber 201 is provided. As shown in FIG. 2, the exhaust port 231a is provided at a position facing (opposite to) the nozzles 249a to 249c (gas supply holes 250a to 250c) with the wafer 200 interposed therebetween in a plan view. The exhaust port 231a may be provided along the upper part from the lower part of the sidewall of the reaction tube 203, that is, along the wafer arrangement region. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure regulation unit). The APC valve 244 can perform vacuum exhaust and stop of vacuum exhaust in the processing chamber 201 by opening and closing the valve with the vacuum pump 246 operating, and further, with the vacuum pump 246 operating, the valve opening degree is adjusted based on the pressure information detected by the pressure sensor 245, so that the pressure in the processing chamber 201 can be adjusted. Mainly, the exhaust system is constituted by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be considered to be included in the exhaust system.

[0023] Below the manifold 209, a seal cap 219 is provided as a furnace port lid body that can airtightly close the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS, for example, and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a seal member that contacts the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 for rotating a boat 217 described later is installed. The rotation shaft 255 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The seal cap 219 is configured to be vertically moved up and down by a boat elevator 115 as an elevating mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) for loading and unloading (transferring) the wafer 200 into and out of the processing chamber 201 by moving the seal cap 219 up and down.

[0024] Below the manifold 209, a shutter 219s is provided as a furnace port lid body that can airtightly close the lower end opening of the manifold 209 in a state where the seal cap 219 is lowered and the boat 217 is unloaded from the processing chamber 201. The shutter 219s is made of a metal material such as SUS, for example, and is formed in a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a seal member that contacts the lower end of the manifold 209. The opening and closing operation (lifting operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0025] The boat 217 as a substrate support tool is configured to support a plurality of wafers 200, for example, 25 to 200 wafers, in a horizontal posture and vertically aligned in a multi-stage manner with their centers aligned with each other, that is, arranged at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC, for example. Below the boat 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages.

[0026] Inside the reaction tube 203, a temperature sensor 263 as a temperature detector is installed. By adjusting the energization state of the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 becomes a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

[0027] As shown in FIG. 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121. In addition, an external storage device 123 can be connected to the controller 121.

[0028] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. Inside the storage device 121c, a control program for controlling the operation of the substrate processing apparatus, a process recipe in which procedures and conditions for substrate processing described later are described, etc. are stored in a readable manner. The process recipe is a combination of each procedure in the substrate processing described later so that the controller 121 can cause the substrate processing apparatus to execute it and obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. Also, the process recipe is simply referred to as a recipe. When the term "program" is used in this specification, it may include only the recipe alone, only the control program alone, or both of them. The RAM 121b is configured as a memory area (work area) that temporarily holds programs, data, etc. read by the CPU 121a.

[0029] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241h, valves 243a to 243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, etc.

[0030] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to be able to read a recipe from the storage device 121c in response to the input of an operation command from the input / output device 122, etc. The CPU 121a is configured to be able to control, in accordance with the content of the read recipe, the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 241h, the opening / closing operation of the valves 243a to 243h, the opening / closing operation of the APC valve 244, the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting operation of the boat 217 by the boat elevator 115, the opening / closing operation of the shutter 219s by the shutter opening / closing mechanism 115s, etc.

[0031] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, magneto-optical disks such as MOs, semiconductor memories such as USB memories and SSDs, etc. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as recording media. When the term "recording medium" is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both of them. Note that the program may be provided to the computer without using the external storage device 123, but by using communication means such as the Internet or a dedicated line.

[0032] (2) Substrate Processing Step Using the above-described substrate processing apparatus, as one step in the manufacturing process of a semiconductor device, an example of a processing sequence for forming a film in recesses such as trenches and holes provided on the surface of a wafer 200 as a substrate will be mainly described with reference to FIGS. 4, 5(a) to 5(e). In the following description, a case where a SiO film, which is an oxide film, is formed as the first film and a SiN film, which is a film other than the SiO film, is formed as the second and third films will be described. In the following description, the operations of each part constituting the substrate processing apparatus are controlled by the controller 121.

[0033] As shown in FIGS. 4, 5(a) to 5(e), the processing sequence in this embodiment is as follows (a) Step A of forming a first film (SiO film) in the recesses by supplying a first film-forming agent to the wafer 200 having recesses on its surface (b) Step B of forming a second film (SiN film) having a chemical composition different from that of the first film (SiO film) on the first film (SiO film) formed in the recesses by supplying a second film-forming agent to the wafer 200 (c) Step C of modifying a part of the second film (SiN film) by supplying a modifier containing fluorine to the wafer 200 (d) Step D of removing the modified part of the second film (SiN film) by supplying an etching agent containing halogen to the wafer 200 (e) Step E of forming a third film (SiN film) on the second film (SiN film) after removing the modified part by supplying a third film-forming agent to the wafer 200 and includes.

[0034] In this specification, for convenience, the above-described processing sequence may be shown as follows. The same notation will be used in the description of the following modification examples and other embodiments.

[0035] Step A → Step B → Step C → Step D → Step E

[0036] As used herein, the expression "different chemical compositions" means that in a film, layer, or region (e.g., a recess provided on the surface of a wafer), at least a part of the elements constituting them is different. For example, when referring to a first film and a second film with different chemical compositions, it means that at least a part of the elements constituting each film is different, such as a SiO film as the first film and a SiN film as the second film.

[0037] As used herein, the term "wafer" may mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. As used herein, the phrase "surface of the wafer" may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. When it is described herein that "a predetermined layer is formed on the wafer", it may mean directly forming a predetermined layer on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When the term "substrate" is used herein, it is synonymous with the case when the term "wafer" is used.

[0038] As used herein, the term "agent" includes at least one of gaseous substances and liquid substances. Liquid substances include mist-like substances. That is, the first film-forming agent (raw material, first reactant), the second film-forming agent (raw material, second reactant), the third film-forming agent (raw material, second reactant), the modifier, and the etching agent may contain a gaseous substance, a liquid substance such as a mist-like substance, or both of them.

[0039] As used herein, the term "layer" includes at least one of continuous layers and discontinuous layers. For example, the Si-containing layer and the modification layer described later may include a continuous layer, a discontinuous layer, or both of them.

[0040] (Wafer Charge and Boat Load) When a plurality of wafers 200 are loaded (wafer charge) into the boat 217, the shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Then, as shown in FIG. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal 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.

[0041] Note that, as shown in FIG. 5(a), the surface of the wafer 200 loaded into the boat 217 is provided with recesses in the shape of trenches or holes. The surface of the recesses provided in the wafer 200 is made of a material having a chemical composition different from that of the SiO film as the first film, that is, a material other than the SiO film, for example, silicon (Si).

[0042] (Pressure adjustment and temperature adjustment) After the boat load is completed, the inside of the processing chamber 201, that is, the space where the wafers 200 are present, is evacuated (depressurized exhaust) by the vacuum pump 246 so as to reach a desired pressure (vacuum degree). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Also, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so as to reach a desired processing temperature. At this time, based on the temperature information detected by the temperature sensor 263, the energization of the heater 207 is feedback-controlled so that the inside of the processing chamber 201 has a desired temperature distribution. Also, the rotation of the wafers 200 by the rotation mechanism 267 is started. The evacuation of the inside of the processing chamber 201, the heating of the wafers 200, and the rotation are all continuously performed at least until the processing of the wafers 200 is completed.

[0043] (Step A) Thereafter, step A is executed. In step A, a first film-forming agent is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 having recesses on its surface, so as to form a SiO film as the first film in the recesses. In this step, as shown in Fig. 5(a), the SiO film is formed in the recesses with a thickness that leaves the opening of the recesses so that a SiN film can be formed in the recesses in step B to be carried out later. Note that in this step, as shown in Fig. 5(a), a SiO film is also formed on the surface (upper surface) of the wafer 200 other than the recesses.

[0044] In this step, for example, a cycle in which step A1 of supplying a raw material to the wafer 200 and step A2 of supplying a first reactant to the wafer 200 are alternately performed is carried out a predetermined number of times (m times, where m is an integer of 1 or more) to form a SiO film. Hereinafter, the method for forming a SiO film including steps A1 and A2 will be specifically described. Note that in the following example, the first film-forming agent includes a raw material and a first reactant.

[0045] [Step A1] In step A1, a raw material (raw material gas) is supplied as the first film-forming agent to the wafer 200 in the processing chamber 201.

[0046] Specifically, valve 243a is opened, and the raw material is caused to flow into gas supply pipe 232a. The raw material that has flowed through gas supply pipe 232a is adjusted in flow rate by MFC241a, supplied into the processing chamber 201 through nozzle 249a, and exhausted from exhaust port 231a. At this time, the raw material is supplied to the wafer 200 from the side of the wafer 200. At this time, valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201 through each of nozzles 249a to 249c.

[0047] The processing conditions for supplying the raw material in step A1 are as follows: Processing temperature: 400 to 700°C, preferably 500 to 650°C Processing pressure: 1 to 2666 Pa, preferably 67 to 1333 Pa Raw material supply flow rate: 0.01 to 2 slm, preferably 0.1 to 1 slm Raw material supply time: 1 to 120 seconds, preferably 1 to 60 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm is exemplified.

[0048] Note that the notation of a numerical range such as "400 to 700 °C" in this specification means that the lower limit value and the upper limit value are included in that range. Thus, for example, "400 to 700 °C" means "400 °C or higher and 700 °C or lower". The same applies to other numerical ranges. Also, the processing temperature in this specification means the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure means the pressure in the processing chamber 201. Also, the processing time means the time for which the processing is continued. Also, when 0 slm is included in the supply flow rate, 0 slm means a case where the substance (gas) is not supplied. These are the same in the following description.

[0049] Under the above processing conditions, by supplying, for example, a chlorosilane-based gas containing Si and chlorine (Cl) as a raw material to the wafer 200, a Si-containing layer containing Cl is formed on the inner surface of the concave portion of the wafer 200. The Si-containing layer containing Cl is formed by physical adsorption or chemical adsorption of the raw material on the inner surface of the concave portion of the wafer 200, chemical adsorption of a substance obtained by partial decomposition of the raw material, deposition of Si by thermal decomposition of the raw material, etc. The Si-containing layer containing Cl may be an adsorption layer (physical adsorption layer or chemical adsorption layer) of the raw material or a substance obtained by partial decomposition of the raw material, or may be a deposition layer of Si containing Cl. In this specification, the Si-containing layer containing Cl is simply also referred to as a Si-containing layer.

[0050] After the Si-containing layer is formed, the valve 243a is closed to stop the supply of the raw material into the processing chamber 201. Then, the inside of the processing chamber 201 is evacuated to remove gases and the like remaining in the processing chamber 201 from the processing chamber 201. At this time, the valves 243f to 243h are opened, and an inert gas is supplied into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied into the processing chamber 201 acts as a purge gas, whereby the inside of the processing chamber 201 is purged (purge).

[0051] As the raw material (raw material gas) which is one of the first film-forming agents, for example, a silane-based gas containing Si which is the main element constituting the SiO film formed on the inner surface of the concave portion can be used. As the silane-based gas, for example, a gas containing Si and a halogen element, that is, a halosilane-based gas can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), and the like.

[0052] Examples of the halosilane gas include chlorosilane gases such as monochlorosilane (SiH3Cl, abbreviation: MCS) gas, dichlorosilane (SiH2Cl2, abbreviation: DCS) gas, trichlorosilane (SiHCl3, abbreviation: TCS) gas, tetrachlorosilane (SiCl4, abbreviation: 4CS) gas, hexachlorodisilane gas (Si2Cl6, abbreviation: HCDS), octachlorotrisilane (Si3Cl8, abbreviation: OCTS) gas, etc.; fluorosilane gases such as tetrafluorosilane (SiF4) gas, difluorosilane (SiH2F2) gas, etc.; bromosilane gases such as tetrabromosilane (SiBr4) gas, dibromosilane (SiH2Br2) gas, etc.; and iodoxysilane gases such as tetraiodosilane (SiI4) gas, diiodosilane (SiH2I2) gas, etc. Further, examples of the halosilane gas include alkylene chlorosilane gases such as bis(trichlorosilyl)methane ((SiCl3)2CH2, abbreviation: BTCSM) gas, 1,2-bis(trichlorosilyl)ethane ((SiCl3)2C2H4, abbreviation: BTCSE) gas, etc.; alkyl chlorosilane gases such as 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH3)2Si2Cl4, abbreviation: TCDMDS) gas, 1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH3)4Si2Cl2, abbreviation: DCTMDS) gas, etc.; and gases containing a cyclic structure composed of Si and C and a halogen such as 1,1,3,3-tetrachloro-1,3-disilacyclobutane (C2H4Cl4Si2, abbreviation: TCDSCB) gas. As the raw material, one or more of these can be used.

[0053] Further, as the raw material, for example, a gas containing Si and hydrogen (H), that is, a silane hydride gas can also be used. Examples of the silane hydride gas include monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, tetrasilane (Si4H 10 ) gas, etc. As the raw material, one or more of these can be used.

[0054] Also, as the raw material, for example, a gas containing Si and an amino group, that is, an aminosilane - based gas can also be used. The amino group can be represented as -NH2, -NHR, -NR2. Here, R represents an alkyl group, and the two Rs in -NR2 may be the same or different.

[0055] As the aminosilane - based gas, for example, tetrakis(dimethylamino)silane (Si[N(CH3)2]4, abbreviation: 4DMAS) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H, abbreviation: 3DMAS) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviation: BDEAS) gas, bis(tert - butylamino)silane (SiH2[NH(C4H9)]2, abbreviation: BTBAS) gas, (diisopropylamino)silane (SiH3[N(C3H7)2], abbreviation: DIPAS) gas, etc. can also be used. As the raw material, one or more of these can be used.

[0056] As the inert gas, for example, nitrogen (N2) gas, or noble gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. As the inert gas, one or more of these can be used. This also applies to each step described later.

[0057] [Step A2] After Step A1 is completed, a first reactant (first reaction gas) is supplied as the first film - forming agent to the wafer 200 in the processing chamber 201, that is, the wafer 200 having a Si - containing layer formed on the inner surface of the concave portion.

[0058] Specifically, open valve 243b and flow the first reactant into gas supply pipe 232b. The first reactant flowing through gas supply pipe 232b is adjusted in flow rate by MFC241b, supplied into processing chamber 201 through nozzle 249b, and exhausted from exhaust port 231a. At this time, the first reactant is supplied to wafer 200 from the side of wafer 200. At this time, an inert gas may be supplied into processing chamber 201 through each of nozzles 249a to 249c.

[0059] As the processing conditions when supplying the first reactant in step A2, Processing temperature: 400 to 700 °C, preferably 500 to 650 °C Processing pressure: 1 to 2000 Pa, preferably 1 to 1000 Pa Supply flow rate of the first reactant (oxidizing agent, O-containing gas): 0.1 to 10 slm Supply flow rate of the first reactant (reducing gas (H-containing gas)): 0 to 10 slm Supply flow rate of inert gas (per gas supply pipe): 0 to 10 slm Supply time of each gas: 1 to 120 seconds, preferably 1 to 60 seconds are exemplified.

[0060] By supplying, for example, an oxidizing agent as the first reactant to wafer 200 under the above-described processing conditions, at least a part of the Si-containing layer formed on the inner surface of the concave portion of wafer 200 is oxidized (modified). As a result, an SiO layer is formed as a layer containing Si and O on the inner surface of the concave portion of wafer 200. When forming the SiO layer, impurities such as Cl contained in the Si-containing layer constitute at least a gaseous substance containing Cl in the process of the modification reaction (oxidation reaction) of the Si-containing layer by the first reactant and are discharged from within processing chamber 201. Thereby, the SiO layer becomes a layer with fewer impurities such as Cl than the Si-containing layer formed in step A1.

[0061] After the SiO layer is formed, valve 243b is closed and the supply of the first reactant into the processing chamber 201 is stopped. Then, in the same procedure as the purge in step A1, the gas and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (purge).

[0062] As the first reactant (first reaction gas), which is one of the first film-forming agents, for example, an oxidizing agent (oxidizing gas) can be used. The oxidizing agent can be used not only by thermally exciting it in a non-plasma atmosphere but also by plasma-exciting it. That is, as the oxidizing agent, an oxidizing agent excited to a plasma state can also be used.

[0063] As the oxidizing agent, for example, oxygen (O2) gas, oxygen (O)-containing gas such as ozone (O3) gas, water vapor (H2O gas), O- and H-containing gas such as hydrogen peroxide (H2O2) gas, nitrous oxide (N2O) gas, nitric oxide (NO) gas, O- and N-containing gas such as nitrogen dioxide (NO2) gas, carbon monoxide (CO) gas, O- and C-containing gas such as carbon dioxide (CO2) gas can be used. Also, as the oxidizing agent, a mixed gas of the above-described O-containing gas and a reducing gas can be used. Here, the reducing gas is a substance that does not obtain an oxidizing action by itself but reacts with the O-containing gas under specific conditions, for example, under the above-described processing conditions, to generate oxidizing species such as atomic oxygen and acts to improve the efficiency of the oxidation treatment. As the reducing gas, for example, hydrogen (H2) gas, deuterium ( 2 H2) gas and other H-containing gases can be used. That is, as the oxidizing agent, for example, O2 gas + H2 gas, O3 gas + H2 gas, etc. can be used. As the first reactant, one or more of these can be used.

[0064] In this specification, the combined description of two gases such as "H2 gas + O2 gas" means a mixed gas of H2 gas and O2 gas. When supplying the mixed gas, the two gases may be mixed (premixed) in the supply pipe and then supplied into the processing chamber 201, or the two gases may be separately supplied into the processing chamber 201 from different supply pipes and mixed (postmixed) in the processing chamber 201.

[0065] [Performed a predetermined number of times] By alternately performing the above steps A1 and A2, that is, by performing a cycle of non-simultaneous operations a predetermined number of times (m times, where m is an integer of 1 or more), as shown in FIG. 5(a), a SiO film can be formed as the first film on the inner surface of the recess of the wafer 200. It is preferable to repeat the above cycle a plurality of times. That is, it is preferable to repeat the above cycle a plurality of times until the thickness of the SiO film formed by laminating SiO layers, with the thickness of the SiO layer formed per cycle being thinner than the desired film thickness, reaches the desired thickness.

[0066] In this step, a SiO film may be formed by a chemical vapor deposition (CVD) method in which the raw material and the first reactant are supplied simultaneously. For example, in this step, a SiO film may be formed in the recess by the CVD method by simultaneously supplying the raw material and the first reactant to the wafer 200 under the same processing conditions as in the above steps A1 and A2. In this case, the film thickness of the SiO film can be adjusted by the supply time of the raw material and the first reactant. Note that the supply time of the raw material and the first reactant may be made longer than the supply time of the raw material and the first reactant in the processing conditions in the above steps A1 and A2. As the raw material and the first reactant used in this method, the same raw materials and first reactants as those exemplified in the above steps A1 and A2 can be used.

[0067] Also, in this step, the surface of the recess formed of Si may be oxidized by thermal oxidation such as dry oxidation, wet oxidation, and reduced-pressure oxidation, or by plasma oxidation, ozone oxidation, etc., to form a SiO film on the inner surface of the recess. For example, in this step, under the same processing conditions as those in the above-mentioned step A2, the above-mentioned step A2 may be performed alone on the wafer 200 to oxidize the inner surface of the recess and form a SiO film on the inner surface of the recess. In this case, the film thickness of the SiO film can be adjusted by the supply time of the first reactant. Note that the supply time of the first reactant may be made longer than the supply time of the first reactant under the processing conditions of the above-mentioned step A2. In the case of this method, the first film-forming agent only needs to contain the first reactant. Also, as the first reactant used in this method, the same first reactants as the various first reactants exemplified in the above-mentioned step A2 can be used.

[0068] The thickness of the SiO film formed in the recess in this step is preferably 5 nm or more, more preferably 10 nm or more, at the thinnest part of the SiO film. If the thickness of the SiO film is less than 5 nm, the function as a modification stopper described later may be insufficient. By setting the thickness of the SiO film to 5 nm or more, the function as a modification stopper can be sufficiently obtained. By setting the thickness of the SiO film to 10 nm or more, the function as a modification stopper can be more sufficiently obtained.

[0069] The thickness of the SiO film formed in the recess in this step is preferably a thickness that does not fill the opening of the recess, that is, a thickness that leaves the opening of the recess. For example, if the recess is columnar, the thickness of the SiO film formed in the recess is preferably less than half of the diameter of the opening of the recess. This is because if the opening of the recess is filled with the SiO film, it becomes difficult to form the SiN film as the second film.

[0070] The upper limit of the thickness of the SiO film formed in the recess may be determined according to the size of the opening of the recess. For example, it is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 15 nm or less. If the thickness of the SiO film exceeds 30 nm, the opening of the recess may become narrow, and the embedding characteristics by the SiN film may not be sufficiently obtained. By setting the thickness of the SiO film to 30 nm or less, this problem can be solved. By setting the thickness of the SiO film to 20 nm or less, this problem can be sufficiently solved. By setting the thickness of the SiO film to 15 nm or less, this problem can be more sufficiently solved.

[0071] From the above, the thickness of the SiO film formed in the recess in this step is preferably 5 nm to 30 nm, more preferably 5 nm to 20 nm, even more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm.

[0072] The SiO film formed in this step has low reactivity with the modifier used in step C to be performed later, and has higher etching resistance than the modified layer formed in step C to be performed later.

[0073] (Step B) After step A is completed, step B is executed. In this step, by supplying a second film-forming agent to the wafer 200 in the processing chamber 201, a SiN film is formed as the second film on the SiO film as the first film formed in the recess in step A. In this step, a SiN film, which is a film containing Si and nitrogen (N), is formed as the second film with a thickness that fills the recess with the SiO film formed on its inner surface. At this time, as shown in FIG. 5(b), the opening of the recess is blocked by the SiN film, and a portion (space generated by voids or seams) that is not filled by the SiN film is formed in the recess. That is, the SiN film formed to fill the recess has a space (gap, hollow portion) in the film. In addition, in this step, as shown in FIG. 5(b), a SiN film is also formed on the SiO film formed on the surface (upper surface) of the wafer 200 other than the recess.

[0074] In this step, for example, a cycle of alternately performing step B1 of supplying a raw material to the wafer 200 and step B2 of supplying a second reactant to the wafer 200 is performed a predetermined number of times (n times, where n is an integer of 1 or more) to form a SiN film. Hereinafter, the method for forming a SiN film including steps B1 and B2 will be specifically described. In the following example, the second film-forming agent includes a raw material and a second reactant.

[0075] [Step B1] In step B1, a raw material (raw material gas) is supplied as the second film-forming agent to the wafer 200 in the processing chamber 201, that is, the wafer 200 having a SiO film formed on the inner surface of the concave portion. This step can be performed under the same processing procedure as step A1 described above and the following processing conditions. By this step, a Si-containing layer can be formed on the SiO film. After forming the Si-containing layer, the gas remaining in the processing chamber 201 is removed from the processing chamber 201 (purged) by the same processing procedure as the purge in step A1 described above. As the raw material, for example, the same raw materials as those exemplified in step A1 described above can be used.

[0076] As the processing conditions for supplying the raw material in step B1, Processing temperature: 400 to 800 °C, preferably 500 to 650 °C Processing pressure: 1 to 2666 Pa, preferably 67 to 1333 Pa Raw material supply flow rate: 0.01 to 2 slm, preferably 0.1 to 1 slm Raw material supply time: 1 to 120 seconds, preferably 1 to 60 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm are exemplified.

[0077] [Step B2] After step B1 is completed, a second reactant (second reaction gas) is supplied as the second film-forming agent to the wafer 200 in the processing chamber 201, that is, the wafer 200 having a Si-containing layer formed on the SiO film formed on the inner surface of the concave portion.

[0078] Specifically, the valve 243c is opened, and the second reactant is flowed into the gas supply pipe 232c. The second reactant flowing through the gas supply pipe 232c is adjusted in flow rate by the MFC241c, supplied into the processing chamber 201 through the nozzle 249c, and exhausted from the exhaust port 231a. At this time, the second reactant is supplied to the wafer 200 from the side of the wafer 200. At this time, an inert gas may be supplied into the processing chamber 201 through each of the nozzles 249a to 249c.

[0079] As the processing conditions for supplying the second reactant in step B2, Processing temperature: 400 to 800 °C, preferably 500 to 650 °C Processing pressure: 1 to 4000 Pa, preferably 1 to 3000 Pa Second reactant supply flow rate: 0.1 to 10 slm Second reaction pair supply time: 1 to 120 seconds, preferably 1 to 60 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm are exemplified.

[0080] By supplying, for example, a nitriding agent (nitriding gas) as the second reactant to the wafer 200 under the above-described processing conditions, at least a part of the Si-containing layer is nitrided (modified). As a result, a SiN layer is formed as a layer containing Si and N on the SiO film formed on the inner surface of the concave portion of the wafer 200. When forming the SiN layer, impurities such as Cl contained in the Si-containing layer constitute a gaseous substance containing at least Cl in the process of the modification reaction (nitriding reaction) of the Si-containing layer by the second reactant, and are discharged from the processing chamber 201. Thereby, the SiN layer becomes a layer with fewer impurities such as Cl than the Si-containing layer formed in step B1.

[0081] After the SiN layer is formed, the valve 243c is closed, and the supply of the second reactant into the processing chamber 201 is stopped. Then, the gas and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (purged) by the same processing procedure as the purge in step A1.

[0082] As the second reactant (second reaction gas), which is one of the second film-forming agents, for example, a nitriding agent (nitriding gas) can be used. Note that the nitriding agent can be used not only by being thermally excited in a non-plasma atmosphere but also by being plasma-excited. That is, as the nitriding agent, a nitriding agent excited to a plasma state can also be used.

[0083] As the nitriding agent, for example, a nitrogen (N)-containing gas can be used. As the N-containing gas, an N- and H-containing gas can be used. As the N- and H-containing gas, for example, nitrogen hydride-based gases such as ammonia (NH3) gas, diazene (N2H2) gas, hydrazine (N2H4) gas, and N3H8 gas can be used. Further, as the N- and H-containing gas, for example, a C-, N- and H-containing gas can be used. As the C-, N- and H-containing gas, for example, ethylamine-based gases such as monoethylamine (C2H5NH2, abbreviation: MEA) gas, diethylamine ((C2H5)2NH, abbreviation: DEA) gas, and triethylamine ((C2H5)3N, abbreviation: TEA) gas, methylamine-based gases such as monomethylamine (CH3NH2, abbreviation: MMA) gas, dimethylamine ((CH3)2NH, abbreviation: DMA) gas, and trimethylamine ((CH3)3N, abbreviation: TMA) gas, and organic hydrazine-based gases such as monomethylhydrazine ((CH3)HN2H2, abbreviation: MMH) gas, dimethylhydrazine ((CH3)2N2H2, abbreviation: DMH) gas, and trimethylhydrazine ((CH3)2N2(CH3)H, abbreviation: TMH) gas can be used. As the second reactant, one or more of these can be used. Note that when using a second reactant containing C such as an amine-based gas or an organic hydrazine-based gas, in step B2, a SiN layer containing C can be formed.

[0084] [Performed a predetermined number of times] By alternately performing the above steps B1 and B2, that is, performing a cycle of non-simultaneous operations a predetermined number of times (n times, where n is an integer of 1 or more), as shown in FIG. 5(b), the recess in the wafer 200 can be filled with a SiN film as the second film. It is preferable to repeat the above cycle a plurality of times. That is, the thickness of the SiN layer formed per cycle is made thinner than the desired film thickness, and the above cycle is preferably repeated a plurality of times until the thickness of the SiN film formed by laminating the SiN layers becomes thick enough to fill the recess in the wafer 200.

[0085] In this step, a SiN film may be formed by a CVD method in which the raw material and the second reactant are supplied simultaneously. For example, in this step, under the same processing conditions as those in steps B1 and B2 above, the raw material and the second reactant may be supplied to the wafer 200 simultaneously to form a SiN film in the recess by the CVD method. In this case, the film thickness of the SiN film can be adjusted by the supply time of the raw material and the second reactant. Note that the supply time of the raw material and the second reactant may be made longer than the supply time of the raw material and the second reactant in the processing conditions in steps B1 and B2 above. As the raw material and the second reactant used in this method, the same raw materials and second reactants as those exemplified in step A1 above and those exemplified in step B2 above can be used.

[0086] (Step C) After step B is completed, step C is executed. In this step, a modifier containing F is supplied to the wafer 200 in the processing chamber 201 to modify a part of the SiN film. Specifically, in this step, a part of the surface side of the SiN film as the second film formed in step B is modified into an F-containing layer, particularly an F-containing SiO layer or SiOF layer as an F- and O-containing layer. The F-containing SiO layer or SiOF layer is also referred to as an Si-, F-, and O-containing layer. Since the F-containing SiO layer or SiOF layer is the modified part of the SiN film, hereinafter, for convenience, it is also referred to as a modified layer. By this step, in the recess of the wafer 200, as shown in FIG. 5(c), a modified layer is formed (stacked) on the SiN film that is maintained without being modified with the SiO film as a base. Note that in this step, as shown in FIG. 5(c), the SiN film formed on the surface (upper surface) other than the recess of the wafer 200 is also modified into the modified layer.

[0087] Specifically, the valve 243d is opened, and the modifier is caused to flow into the gas supply pipe 232d. The modifier that has flowed through the gas supply pipe 232d is adjusted in flow rate by the MFC241d, supplied into the processing chamber 201 through the nozzle 249a, and exhausted from the exhaust port 231a. At this time, the modifier is supplied to the wafer 200 from the side of the wafer 200. At this time, an inert gas may be supplied into the processing chamber 201 through each of the nozzles 249a to 249c.

[0088] As processing conditions for supplying the modifier in step C, Processing temperature: 100 to 500°C, preferably 350 to 450°C Processing pressure: 1 to 2666 Pa, preferably 67 to 1333 Pa Modifier supply flow rate: 0.001 to 2 slm, preferably 0.002 to 1 slm Modifier supply time: 30 seconds to 30 minutes, preferably 1 minute to 20 minutes Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm are exemplified.

[0089] By supplying a modifier containing F to the wafer 200 under the above processing conditions, a part of the SiN film embedded in the concave portion is modified into a modified layer (F-containing SiO layer or SiOF layer). Since the modification of the SiN film into the modified layer proceeds from the surface of the SiN film in the depth direction in accordance with the supply of the modifier to the surface of the SiN film, among the SiN films in the concave portion, the SiN film located on the surface side (the upper side in FIG. 5(c)) is converted into a modified layer (F-containing SiO layer or SiOF layer). The thickness of the modified layer can be controlled by the supply conditions of the modifier to the wafer 200.

[0090] In this step, the SiO film as the first film formed in step A can act as a modification inhibitor film. Thereby, even when a part of the region from the surface of the SiN film to the portion in contact with a part of the SiO film is modified, it is possible to suppress the modification of the SiO film by the modifier. In other words, the SiO film formed in step A can suppress or stop the progress of the modification of the SiO film itself in the depth direction by the modifier. That is, the SiO film functions as a modification stopper. Thereby, during the implementation of this step, it is possible to prevent the alteration of the inner surface of the concave portion of the wafer 200 under the SiO film and the damage to the inner surface of the concave portion.

[0091] The reason why the SiO film functions as a modification stopper is that the reactivity between the modifier and the SiO film is lower than the reactivity between the modifier and the SiN film. In other words, as the modifier, a substance with lower reactivity with the SiO film than with the SiN film is used. Further in other words, it can also be said that the modifier is supplied under processing conditions where the reactivity between the modifier and the SiO film is lower than the reactivity between the modifier and the SiN film. By utilizing such a difference in reactivity, in this step, it is possible to selectively modify a part of the SiN film while suppressing or stopping the progress of the modification of the SiO film. Depending on the processing conditions, it is also possible to prevent the reaction between the modifier and the SiO film, that is, to prevent the modification of the SiO film.

[0092] From the above, in this step, the modification of the SiN film can be advanced directionally and selectively in the depth direction within the recess, and a modified layer having a shape as shown in Fig. 5(c) can be formed. As a result, within the recess, a laminated film is present in a state where a modified layer (F-containing SiO layer or SiOF layer) is laminated on the SiN film that is maintained without being modified with the SiO film as the base.

[0093] In this step, it is preferable to modify at least a region of the SiN film up to a location in contact with at least a part of the space (void or seam) generated during the formation of the SiN film from the surface of the SiN film. That is, in this step, it is preferable to advance the modification of the SiN film to a position deeper than the upper part of the space (void or seam) in the SiN film. For example, it is preferable to advance the modification of the SiN film to at least half of the depth of the space in the SiN film. Also for example, it is more preferable to advance the modification of the SiN film to a position exceeding half of the depth of the space in the SiN film. Further for example, it is more preferable to advance the modification of the SiN film to a position of 2 / 3 or more of the depth of the space in the SiN film. Note that Fig. 5(c) shows an example where the modification of the SiN film is advanced to a position of 2 / 3 or more of the depth of the space in the SiN film.

[0094] By advancing the modification of the SiN film in this way, by removing the modified layer in step D to be performed later, at least a part of the space in the SiN film within the recess can be eliminated and the space can be opened. As a result, the space within the recess can be filled with the third film formed in step E to be performed after step D. Note that the modification of the SiN film can also be advanced to the same depth as the bottom of the space in the SiN film. In this case, by removing the modified layer in step D to be performed later, the space itself in the SiN film can be eliminated.

[0095] In this way, in this step, by functioning as a modification stopper, the SiO film can selectively modify a part of the SiN film without altering the inner surface of the recess formed of Si or the like and without damaging the inner surface of the recess.

[0096] After the modified layer is formed, the valve 243d is closed to stop the supply of the modifier into the processing chamber 201. Then, in the same processing procedure as the purge in step A1, the gas and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (purge).

[0097] As the modifier (modifying gas), for example, it is preferable to use a substance containing F, more preferably to use a substance containing F and O, and even more preferably to use a substance containing F, O, and N. Also, as the modifier, for example, it is preferable to use an F-containing gas, more preferably to use an F- and O-containing gas, and even more preferably to use an F-, O-, and N-containing gas. That is, the modifier preferably contains F, more preferably contains F and O, and even more preferably contains F, O, and N. Further, as the modifier, for example, a mixed gas of an N- and O-containing gas and an F-containing gas, a mixed gas of an F-, N-, and O-containing gas and an F-containing gas, or an F-, N-, and O-containing gas can also be used. By using such modifiers, it becomes possible to modify a part of the SiN film as the second film into a layer (F-containing SiO layer or SiOF layer) that is easily removed by an etchant.

[0098] As the modifier, for example, NO gas + fluorine (F2) gas, NO gas + chlorine monofluoride (ClF) gas, NO gas + chlorine trifluoride (ClF3) gas, NO gas + nitrogen trifluoride (NF3) gas, nitrosyl fluoride (FNO) gas + F2 gas, FNO gas + ClF gas, FNO gas + ClF3 gas, FNO gas + NF3 gas, FNO gas, etc. can be used. As the modifier, one or more of these can be used. In addition, for gases that are difficult to store, such as FNO gas, it is preferable to generate them by mixing F2 gas and NO gas, for example, in a supply pipe or a nozzle, and supply them into the processing chamber 201. In this case, a mixed gas of F2 gas, NO gas, and FNO gas is supplied into the processing chamber 201.

[0099] (Step D) After step C is completed, step D is executed. In this step, an etchant containing halogen is supplied to the wafer 200 in the processing chamber 201 to remove the modified portion (modified layer) of the SiN film. That is, in this step, in step C, the modified portion (modified layer) of the SiN film that has been modified to the F-containing SiO layer or SiOF layer is removed. By this step, as shown in FIG. 5(d), the SiN film that has been maintained without being modified remains in the recess of the wafer 200, the surface of the SiN film is exposed, and at the same time, a part of the SiO film, that is, the portion in contact with the modified layer is exposed. In addition, in this step, as shown in FIG. 5(d), the modified layer on the surface (upper surface) of the wafer 200 other than the recess is also removed, and the SiO film is exposed.

[0100] Specifically, the valve 243e is opened, and the etchant is allowed to flow into the gas supply pipe 232e. The flow rate of the etchant is adjusted by the MFC241e, and it is supplied into the processing chamber 201 through the gas supply pipe 232b and the nozzle 249b, and exhausted from the exhaust port 231a. At this time, the etchant is supplied to the wafer 200 from the side of the wafer 200. At this time, an inert gas may be supplied into the processing chamber 201 through each of the nozzles 249a to 249c.

[0101] When supplying the etchant in step D, the processing conditions are as follows: Processing temperature: room temperature (25 °C) to 600 °C, preferably 50 to 200 °C Processing pressure: 1 to 13332 Pa, preferably 100 to 1333 Pa Etchant supply flow rate: 0.05 to 5 slm, preferably 0.1 to 2 slm Etchant supply time: 0.1 to 30 minutes, preferably 1 to 10 minutes Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm are exemplified.

[0102] By supplying the etchant to the wafer 200 under the above processing conditions, the modified portion of the SiN film, that is, the modified layer (F-containing SiO layer or SiOF layer) is removed. At this time, the SiO film formed in step A can act as an etching inhibition film, and even when etching the modified layer in contact with the SiO film, it is possible to suppress the etching of the SiO film. That is, the SiO film can suppress or stop the progress of etching in the depth direction of the SiO film, that is, the etching progress toward the substrate side of the SiO film. That is, the SiO film functions as an etching stopper. As a result, it is possible to prevent the alteration of the inner surface of the recess of the wafer 200, which is the substrate of the SiO film, and the damage to the inner surface of the recess even while this step is being carried out.

[0103] The reason why the SiO film functions as an etching stopper is that the reactivity between the etchant and the SiO film is lower than that between the etchant and the modified layer (F-containing SiO layer or SiOF layer). In other words, as the etchant, a substance with lower reactivity with the SiO film than with the modified layer is used. Further in other words, it can also be said that the etchant is supplied under processing conditions where the reactivity between the etchant and the SiO film is lower than that between the etchant and the modified layer. By utilizing such a difference in reactivity, in this step, it becomes possible to selectively etch the modified layer while suppressing or stopping the progress of the etching of the SiO film. Note that the SiO film is an F-free film, while the modified layer is an F-containing layer. This difference in chemical composition between the SiO film and the modified layer is one of the reasons why the etching rate of the SiO film is lower than that of the modified layer, in other words, one of the reasons why the etching resistance of the SiO film is higher than that of the modified layer.

[0104] From the above, in this step, the etching of the F-containing SiO layer or SiOF layer-modified portion of the SiN film, that is, the modified layer, can be made to proceed directionally in the depth direction within the recess and selectively. As a result, as shown in FIG. 5(d), within the recess, a SiN film that has been maintained without being modified, with the SiO film as the base, remains, and the portion of the SiO film that was in contact with the modified layer is exposed.

[0105] After removing the modified layer and exposing the surface of the SiN film that has been maintained without being modified, valve 243e is closed, and the supply of the etchant into the processing chamber 201 is stopped. Then, the inside of the processing chamber 201 is evacuated, and gaseous substances and the like remaining in the processing chamber 201 are removed from the processing chamber 201. And, by the same processing procedure as the purge in step A1 described above, gaseous substances and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (purge).

[0106] As the etching agent (etching gas), it is preferable to use a substance containing a halogen, for example, a substance containing at least one of F, Cl, and I. Thereby, it becomes possible to effectively selectively remove the modified portion (modified layer) of the SiN film as the second film while suppressing the etching of the SiO film as the first film.

[0107] As the etching agent, for example, F2 gas, NF3 gas, ClF3 gas, ClF gas, tungsten hexafluoride (WF6) gas, iodine heptafluoride (IF7) gas, iodine pentafluoride (IF5) gas, hexafluoroacetylacetone (C5H2F6O2) gas, hydrogen fluoride (HF) gas, FNO gas, chlorine (Cl2) gas, hydrogen chloride (HCl) gas, boron trichloride (BCl3) gas, thionyl chloride (SOCl2) gas, tungsten hexachloride (WCl6) gas, etc. can be used. As the etching agent, one or more of these can be used.

[0108] Note that the modifier used in step C and the etching agent used in step D may be the same substance (gas). For example, FNO gas can be used as the modifier in step C and FNO gas can be used as the etching agent in step D. In this case, by controlling the processing conditions for each of steps C and D, it becomes possible to make FNO gas act as a modifier in step C and FNO gas act as an etching agent in step D.

[0109] (Step E) After step D is completed, step E is executed. In this step, by supplying a third film-forming agent to the wafer 200 in the processing chamber 201, a SiN film is formed as the third film on the SiN film after the modified layer is removed. In this step, as shown in FIG. 5(e), a SiN film is formed as the third film with a thickness that fills the concave portion on the SiN film (the SiN film that was maintained without being modified) remaining in the concave portion after the modified layer was removed in step D. Note that in this step, as shown in FIG. 5(e), a SiN film is also formed on the surface of the wafer 200 other than the concave portion.

[0110] When step D is completed, a SiN film as the second film that has been maintained without being modified remains on the bottom side within the recess of the wafer 200. As a result, the depth of the recess (trench or hole), that is, the aspect ratio is relaxed (decreased), and even if a SiN film as the third film is formed with a thickness to fill the recess, it is possible to fill the recess without generating voids or seams.

[0111] In this step, as the third film-forming agent, the same raw material and the second reactant as those in the second film-forming agent in step B described above are used, and a SiN film as the third film can be formed under the same processing procedure and processing conditions as in step B described above. As the raw material, for example, the same raw materials as the various raw materials exemplified in step B1 (step A1) described above can be used, and as the second reactant, for example, the same second reactants as the various second reactants exemplified in step B2 described above can be used.

[0112] (After purge and atmospheric pressure recovery) After step E is completed, an inert gas is supplied into the processing chamber 201 as a purge gas from each of the nozzles 249a to 249c, and exhausted from the exhaust port 231a. As a result, the inside of the processing chamber 201 is purged, and the gas and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after purge). Then, the atmosphere inside the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is restored to normal pressure (atmospheric pressure recovery).

[0113] (Boat unloading and wafer discharge) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafer 200 is carried out (boat unloading) from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported by the boat 217. After the boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After the processed wafer 200 is carried out to the outside of the reaction tube 203, it is taken out from the boat 217 (wafer discharge).

[0114] Steps A, B, C, D, and E are preferably performed in the same processing chamber (in-situ). Thereby, steps A, B, C, D, and E can be performed without exposing the wafer 200 to the atmosphere, that is, while maintaining the surface of the wafer 200 in a clean state.

[0115] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained.

[0116] In this embodiment, the first film is formed in step A in the recess provided on the surface of the wafer 200 before forming the second film in step B. Thereby, when modifying a part of the second film in step C, the first film can act as a modification suppression film, and when removing the modified part (modified layer) of the second film in step D, the first film can act as an etching suppression film. That is, the first film formed in the recess before forming the second film can function as a modification stopper when modifying a part of the second film, and can also function as an etching stopper when removing the modified part (modified layer) of the second film. As a result, it becomes possible to modify a part of the second film and remove the modified part (modified layer) of the second film without altering the inner surface of the recess and without damaging the inner surface of the recess. As a result, it becomes possible to form a film with high precision in the recess.

[0117] In this aspect, in the recess having an inner surface maintained in a proper state without being deteriorated and not damaged, the third film can be formed in step E. Thereby, it becomes possible to form a film with high accuracy in the recess. As a result, it becomes possible to embed the inside of the recess with a film with high accuracy. Note that by making the material of the third film the same as the material of the second film, it becomes possible to embed the inside of the recess with a film of the same material. Also, by making the material of the third film different from the material of the second film, it becomes possible to embed the inside of the recess with a film (laminated film) of a different material.

[0118] In this aspect, in step A, a SiO film which is an oxide film is formed as the first film. Since the first film is an oxide film in this way, when a part of the SiN film as the second film is modified in step C, the first film can effectively function as a modification stopper, and when removing the modified part (modified layer) of the SiN film in step D, the first film can effectively function as an etching stopper. Also, since the first film is a SiO film, when a part of the SiN film as the second film is modified in step C, the first film can function more effectively as a modification stopper, and when removing the modified part (modified layer) of the SiN film in step D, the first film can function more effectively as an etching stopper.

[0119] In this aspect, in step B, a film other than the SiO film, that is, a SiN film which has a chemical composition different from that of the SiO film, is formed as the second film. Since the second film is a film other than the SiO film, that is, a film having a chemical composition different from that of the SiO film, particularly a SiN film, in this way, it becomes possible to make the second film a film that is easily modified by a modifier and difficult to be removed by an etchant.

[0120] In this aspect, a wafer 200 is used in which the surface of the recess is made of a material other than the SiO film, that is, Si, which is a material having a chemical composition different from that of the SiO film. By configuring the surface of the recess with a material other than the SiO film, that is, a material having a chemical composition different from that of the SiO film, particularly a material containing Si, it becomes possible to more remarkably produce the above-described effects.

[0121] In this aspect, the reactivity of the modifier with the first film is made lower than the reactivity of the modifier with the second film. That is, the reactivity of the modifier with the second film is made higher than the reactivity of the modifier with the first film. Thereby, in step C, it becomes possible to selectively modify a part of the second film while suppressing the modification of the first film.

[0122] In this aspect, in step C, a part of the region from the surface of the second film to the location in contact with a part of the first film is modified, and in step D, a part of the first film is exposed. By such steps C and D, it becomes possible to selectively modify a part of the second film while suppressing the modification of the first film, and to selectively remove the modified part (modified layer) of the second film while suppressing the etching of the first film.

[0123] In this aspect, the second film has a seam or void, and in step C, a region of the second film from the surface of the second film to at least the location in contact with at least a part of the seam or void is modified, and in step D, while removing the modified region (modified layer), at least a part of the seam or void is eliminated. By eliminating at least a part of the seam or void in the second film in this way, it becomes possible to perform seamless and void-free embedding into the recess.

[0124] In this embodiment, in step C, a part of the second film is modified to a layer containing F and O, particularly a layer containing Si, F, and O. Thereby, it becomes possible to modify a part of the second film to a layer that is easily removed by an etching agent, and it becomes possible to effectively selectively remove the modified part of the second film while suppressing the etching of the first film.

[0125] In this embodiment, the reactivity between the etching agent and the first film is made lower than the reactivity between the etching agent and the modified part (modified layer) of the second film. That is, the reactivity between the etching agent and the modified layer is made higher than the reactivity between the etching agent and the first film. Thereby, it becomes possible to selectively remove the modified part of the second film while suppressing the etching of the first film.

[0126] (4) Variation The processing sequence in this embodiment can be changed as in the following variations. These variations can be arbitrarily combined. Unless otherwise specified, the processing procedures and processing conditions in each step of each variation can be the same as those in each step of the above-described processing sequence.

[0127] (Variation 1) As in the following processing sequence, the cycle of step C → step D may be performed a plurality of times (y times, where y is an integer of 2 or more).

[0128] Step A → Step B → (Step C → Step D) × y → Step E

[0129] Also in this modified example, the same effects as those in the above-described embodiment can be obtained. Further, according to this modified example, even when the etching amount (removal amount) of the SiN film formed in step B is insufficient after steps C and D are completed, the etching amount can be increased by performing the cycle of step C → step D a plurality of times. Also, in this case, it becomes possible to control the etching amount according to the number of cycles (y), and it is also possible to enhance the controllability of the etching amount. According to this modified example, even in such a case, it is possible to perform the embedding while controlling the etching amount, and it is possible to perform void-free and seamless embedding.

[0130] (Modified Example 2) As in the processing sequence shown below, the cycle of step C → step D → step E may be performed a plurality of times (z times, where z is an integer of 2 or more).

[0131] Step A → Step B → (Step C → Step D → Step E) × z

[0132] Also in this modified example, the same effects as those in the above-described embodiment can be obtained. Further, according to this modified example, for example, even when a void or a seam (space) occurs in the SiN film as the third film formed in step E in the case where the concave portion is deep (the aspect ratio is large), the cycle of step C → step D → step E is performed a plurality of times, so that the void or the seam can be eliminated while embedding the concave portion. According to this modified example, even in such a case, it is possible to perform void-free and seamless embedding.

[0133] (Modified Example 3) The material of the third film formed in step E may be made different from the material of the second film formed in step B. By making the material of the third film different from the material of the second film, it becomes possible to fill the inside of the recess with films (laminated films) of different materials. In this case, as the third film-forming agent (third raw material, third reactant) used in step E, a film-forming agent (second raw material, second reactant) different from the second film-forming agent used in step B is used, and by selecting a processing procedure and processing conditions according to the material of the third film, the third film can be formed. In this case, by making at least one of the raw materials and reactants different between step E and step B, the material of the third film can be made different from the material of the second film. Also in this modification example, it is possible to form a film with high accuracy inside the recess.

[0134] <Other aspects of the present disclosure> As described above, the aspects of the present disclosure have been specifically described. However, the present disclosure is not limited to the above-described aspects, and various modifications can be made without departing from the gist thereof.

[0135] For example, in the above-described aspects and modification examples, the example of performing steps A, B, C, D, and E has been described, but step E in the above-described aspects may be omitted as in the following processing sequence. For example, in step E, if it is not necessary to fill the inside of the recess with the third film, step E can be omitted. Also in this aspect, it is possible to form a film with high accuracy inside the recess.

[0136] Step A → Step B → Step C → Step D Step A → Step B → (Step C → Step D) × y

[0137] Also, for example, in the above-described embodiments and variations, the steps A, B, C, D, and E have been described as being performed in the same processing chamber 201 (in-situ). However, at least one of the steps A, B, C, D, and E may be performed in a different processing chamber (processing unit, processing space) (ex-situ). If at least one of the steps A, B, C, D, and E is performed in separate processing chambers, the temperature in each processing chamber can be preset, for example, to the processing temperature at each step or a temperature close thereto, thereby shortening the time required for temperature adjustment and increasing production efficiency.

[0138] Also, for example, in the above-described embodiments and variations, an example in which the surface of the concave portion is formed of Si has been described. However, the surface of the concave portion may be formed of a material having a chemical composition different from that of the first film. For example, it may be formed of a material containing Si. For example, the surface of the concave portion may be formed of at least one of single-crystal Si, an Si film, an SiN film, a silicon carbide film (SiC film), a silicon carbonitride film (SiCN film), a silicon oxycarbonitride film (SiOCN film), a silicon oxycarbide film (SiOC film), a silicon oxynitride film (SiON film), a silicon boron carbonitride film (SiBCN film), a silicon boron nitride film (SiBN), a silicon boron carbide film (SiBC film), and a silicon borate film (SiBO film).

[0139] Also, for example, in the above-described embodiments and variations, an example in which the second film and the third film are SiN films has been described. However, the second film and the third film may be any film other than the SiO film. For example, they may be films containing Si and N. For example, the second film and the third film may contain at least one of an SiN film, an SiCN film, an SiOCN film, an SiOCN film, an SiON film, an SiBCN film, and an SiBN film.

[0140] The recipes used for each process are preferably prepared individually according to the process content and stored in the storage device 121c via a telecommunication line or an external storage device 123. When starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe from among a plurality of recipes stored in the storage device 121c according to the process content. As a result, it becomes possible to form films with various film types, composition ratios, film qualities, and film thicknesses with good reproducibility using a single substrate processing apparatus. In addition, the burden on the operator can be reduced, operation mistakes can be avoided, and each process can be started quickly.

[0141] The above-described recipes are not limited to newly created ones. For example, they may be prepared by modifying existing recipes already installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via a telecommunication line or a recording medium on which the recipe is recorded. Alternatively, the input / output device 122 provided in the existing substrate processing apparatus may be operated to directly modify the existing recipe already installed in the substrate processing apparatus.

[0142] In the above-described aspect, an example of forming a film using a batch-type substrate processing apparatus that processes a plurality of substrates at a time has been described. The present disclosure is not limited to the above-described aspect. For example, it can also be suitably applied when forming a film using a single-wafer-type substrate processing apparatus that processes one or several substrates at a time. Further, in the above-described aspect, an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace has been described. The present disclosure is not limited to the above-described aspect and can also be suitably applied when forming a film using a substrate processing apparatus having a cold-wall type processing furnace.

[0143] Even when using these substrate processing apparatuses, each process can be performed with the same processing procedures and processing conditions as in the above-described aspects and modified examples, and the same effects as in the above-described aspects and modified examples can be obtained.

[0144] The above-described embodiments and modifications can be used in appropriate combinations. At this time, the processing procedures and processing conditions can be the same as those in the above-described embodiments and modifications, for example.

Explanation of Reference Numerals

[0145] 200 wafers (substrates)

Claims

1. (a) A step of forming a first film in the recess by supplying a first film-forming agent to a substrate having a recess on its surface; (b) A step of forming a second film having a chemical composition different from that of the first film on the first film formed in the recess by supplying a second film-forming agent to the substrate; (c) A step of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; (d) A step of removing the modified part of the second film by supplying an etching agent containing halogen to the substrate; characterized by a substrate processing method in which the reactivity of the modifier with the first film is lower than the reactivity of the modifier with the second film.

2. (a) A step of forming a first film in the recess by supplying a first film-forming agent to a substrate having a recess on its surface; (b) A step of forming a second film having a chemical composition different from that of the first film on the first film formed in the recess by supplying a second film-forming agent to the substrate; (c) A step of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; (d) A step of removing the modified part of the second film by supplying an etching agent containing halogen to the substrate; characterized by a substrate processing method in which the reactivity of the etching agent with the first film is lower than the reactivity of the etching agent with the modified part of the second film.

3. (e) A step of forming a third film on the second film after removing the modified part by supplying a third film-forming agent to the substrate, the substrate processing method according to claim 1 or 2, further comprising.

4. The substrate processing method according to claim 1 or 2, wherein the first film is an oxide film.

5. The substrate processing method according to claim 1 or 2, wherein the first film is a silicon oxide film.

6. The substrate processing method according to claim 1 or 2, wherein the second film is a film other than a silicon oxide film.

7. The substrate processing method according to claim 1 or 2, wherein the second film is a film containing silicon and nitrogen.

8. The substrate processing method according to claim 1 or 2, wherein the surface of the recess is made of a material other than a silicon oxide film.

9. The substrate processing method according to claim 1 or 2, wherein the surface of the recess is made of a material containing silicon.

10. The substrate processing method according to claim 1 or 2, wherein the modifier contains fluorine and oxygen.

11. The substrate processing method according to claim 1 or 2, wherein the modifier contains fluorine, nitrogen, and oxygen.

12. The substrate processing method according to claim 1 or 2, wherein the modifier is a mixed gas of a nitrogen- and oxygen-containing gas and a fluorine-containing gas, a mixed gas of a fluorine-, nitrogen- and oxygen-containing gas and a fluorine-containing gas, or a fluorine-, nitrogen- and oxygen-containing gas.

13. In (c), a part of the region of the second film from the surface of the second film to the portion in contact with a part of the first film is modified, and in (d), a part of the first film is exposed. The substrate processing method according to claim 1 or 2.

14. The second film has a seam or void, In (c), a region of the second film from the surface of the second film to at least the portion in contact with at least a part of the seam or void is modified, and in (d), at least a part of the seam or void is eliminated. The substrate processing method according to claim 1 or 2.

15. In (c), a part of the second film is modified into a fluorine- and oxygen-containing layer. The substrate processing method according to claim 1 or 2.

16. In (c), a part of the second film is modified into a silicon-, fluorine- and oxygen-containing layer. The substrate processing method according to claim 1 or 2.

17. The etching agent is a substance containing at least one of fluorine, chlorine, and iodine. The substrate processing method according to claim 1 or 2.

18. (a) A step of forming a first film in the recess by supplying a first film-forming agent to a substrate having a recess on its surface; (b) A step of forming a second film having a chemical composition different from that of the first film on the first film formed in the recess by supplying a second film-forming agent to the substrate; (c) A step of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; (d) A step of removing the modified part of the second film by supplying an etching agent containing halogen to the substrate; having A method for manufacturing a semiconductor device, wherein the reactivity of the modifier with the first film is lower than the reactivity of the modifier with the second film.

19. (a) A step of forming a first film in the recess by supplying a first film-forming agent to a substrate having a recess on its surface; (b) A step of forming a second film having a chemical composition different from that of the first film on the first film formed in the recess by supplying a second film-forming agent to the substrate; (c) a step of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; (d) a step of removing the modified portion of the second film by supplying an etchant containing halogen to the substrate; It has A method for manufacturing a semiconductor device, wherein the reactivity of the modifier with the first film is lower than the reactivity of the modifier with the second film.

20. A first film-forming agent supply system for supplying a first film-forming agent to a substrate, A second film-forming agent supply system for supplying a second film-forming agent to a substrate, A modifier supply system for supplying a modifier containing fluorine to a substrate, An etchant supply system for supplying an etchant containing halogen to a substrate, (a) a process of forming a first film in the recess by supplying the first film-forming agent to a substrate having a recess on its surface; (b) a process of forming a second film having a chemical composition different from that of the first film on the first film formed in the recess by supplying the second film-forming agent to the substrate; (c) a process of modifying a part of the second film by supplying the modifier to the substrate; (d) a process of removing the modified portion of the second film by supplying the etchant to the substrate, and a control unit configured to be able to control the first film-forming agent supply system, the second film-forming agent supply system, the modifier supply system, and the etchant supply system so as to perform the above processes; A substrate processing apparatus having A substrate processing apparatus, wherein the reactivity of the modifier with the first film is lower than the reactivity of the modifier with the second film.

21. A first film-forming agent supply system for supplying a first film-forming agent to a substrate, A second film-forming agent supply system for supplying a second film-forming agent to a substrate, A modifier supply system for supplying a modifier containing fluorine to a substrate, An etchant supply system for supplying an etchant containing halogen to a substrate, By supplying the first film-forming agent to a substrate having recesses on its surface, a process of forming a first film in the recesses; (b) By supplying the second film-forming agent to the substrate, a process of forming a second film having a chemical composition different from that of the first film on the first film formed in the recesses; (c) By supplying the modifier to the substrate, a process of modifying a part of the second film; (d) By supplying the etching agent to the substrate, a process of removing the modified part of the second film; A control unit configured to be able to control the first film-forming agent supply system, the second film-forming agent supply system, the modifier supply system, and the etching agent supply system so as to perform the above processes. A substrate processing apparatus having A substrate processing apparatus in which the reactivity of the etching agent with the first film is lower than the reactivity of the etching agent with the modified part of the second film.

22. A procedure of forming a first film in the recesses by supplying a first film-forming agent to a substrate having recesses on its surface; A procedure of forming a second film having a chemical composition different from that of the first film on the first film formed in the recesses by supplying a second film-forming agent to the substrate; A procedure of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; A procedure of removing the modified part of the second film by supplying an etching agent containing a halogen to the substrate; A program for causing a computer to execute the above procedures in a substrate processing apparatus, A program in which the reactivity of the modifier with the first film is lower than the reactivity of the modifier with the second film.

23. (a) A procedure of forming a first film in the recesses by supplying a first film-forming agent to a substrate having recesses on its surface; A procedure of forming a second film having a chemical composition different from that of the first film on the first film formed in the recesses by supplying a second film-forming agent to the substrate; A procedure of modifying a part of the second film by supplying a modifier containing fluorine to the substrate; A procedure of removing the modified part of the second film by supplying an etching agent containing a halogen to the substrate; A program for causing a computer to execute the above procedures in a substrate processing apparatus, A program in which the reactivity of the etching agent with the first film is lower than the reactivity of the etching agent with the modified portion of the second film.

Images