JP2022174756A - Substrate processing method, semiconductor device manufacturing method, substrate processing apparatus, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method, a semiconductor device manufacturing method, a substrate processing apparatus, and a program capable of increasing selectivity in selective growth while suppressing damage to the surface of an underlying layer.

SOLUTION: A substrate processing method includes a processing sequence including a step of providing a substrate having, on its surface, an oxygen-free first underlayer, an oxygen-containing second underlayer, and an oxygen and nitrogen-free third underlayer having a protective film formed thereon, a step C of modifying the surface of the second underlayer so as to be fluorine-terminated by supplying a fluorine-containing gas to the substrate while the protective film is formed on the surface of the third underlayer in selective growth, and a step D of forming a film on the surface of the first underlayer by supplying a film-forming gas to the substrate while the surface of the second underlayer is modified.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2023,JPO&INPIT

Description

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

As one step in the manufacturing process of a semiconductor device, a process for selectively growing a film on a specific underlying surface among a plurality of types of underlying material exposed on the surface of a substrate (hereinafter referred to as selective growth or selective growth). (also referred to as film formation) may be performed (see, for example, Patent Document 1).

JP 2013-243193 A

An object of the present disclosure is to provide a technique capable of increasing selectivity in the selective growth described above while suppressing damage to the surface of the underlayer.

According to one aspect of the present disclosure,
(a) supplying a processing gas to a substrate having an exposed surface of a first underlayer containing no oxygen, a second underlayer containing oxygen, and a third underlayer containing no oxygen and nitrogen; forming a protective film on the surface of the third underlayer;
(b) modifying the surface of the second underlayer so that the surface of the second underlayer is fluorine-terminated by supplying a fluorine-containing gas to the substrate after the protective film is formed on the surface of the third underlayer;
(c) selectively forming a film on the surface of the first underlayer by supplying a film-forming gas to the substrate after modifying the surface of the second underlayer;
technology is provided.

According to the present disclosure, it is possible to improve selectivity in the selective growth described above while suppressing damage to the surface of the base.

FIG. 1 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one aspect of the present disclosure, and is a longitudinal sectional view showing a processing furnace 202 portion. FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one aspect of the present disclosure, and is a cross-sectional view showing the processing furnace 202 portion taken along line AA of FIG. FIG. 3 is a schematic configuration diagram of the controller 121 of the substrate processing apparatus preferably used in one aspect of the present disclosure, and is a block diagram showing the control system of the controller 121. As shown in FIG. FIG. 4 is a diagram illustrating a processing sequence in selective growth according to one aspect of the present disclosure. FIG. 5A is a partially enlarged cross-sectional view of the surface of the wafer 200 before cleaning. FIG. 5B is an enlarged cross-sectional partial view of the surface of the wafer 200 after the cleaning process, in which the underlayer 200a containing the silicon nitride film, the underlayer 200b containing the silicon oxide film, and the underlayer 200c containing silicon are exposed on the surface. be. FIG. 5(c) is a partially enlarged cross-sectional view of the surface of the wafer 200 after forming the protective film 200e on the surface of the underlayer 200c by supplying the oxygen-containing gas. FIG. 5D is a partially enlarged cross-sectional view of the surface of the wafer 200 after silicon is selectively adsorbed on the respective surfaces of the underlayer 200b and the protective film 200e by supplying an aminosilane-based gas. FIG. 5E is an enlarged sectional view of the surface of the wafer 200 after selectively modifying the surfaces of the base 200b and the protective film 200e on which silicon is adsorbed by supplying a fluorine-containing gas. It is a diagram. FIG. 5(f) is a partially enlarged sectional view of the surface of the wafer 200 after selectively forming a silicon nitride film on the surface of the underlayer 200a. FIG. 5(g) is a cross-sectional partial enlarged view of the surface of the wafer 200 after the wafer 200 shown in FIG. 5(f) has been exposed to the air.

<One aspect of the present disclosure>
One aspect of the present disclosure will be described below mainly with reference to FIGS. 1 to 4. FIG.

(1) Configuration of Substrate Processing Apparatus As shown in FIG. 1, the processing furnace 202 has a heater 207 as a heating mechanism (temperature control unit). The heater 207 has a cylindrical shape and is installed vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation section) that thermally activates (excites) the gas.

A reaction tube 203 is arranged concentrically with the heater 207 inside the heater 207 . The reaction tube 203 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is arranged concentrically with the reaction tube 203 below 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 open upper and lower ends. The upper end of the manifold 209 engages the lower end of the reaction tube 203 and is configured to support the reaction tube 203 . An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. Reactor tube 203 is mounted vertically like heater 207 . A processing vessel (reaction vessel) is mainly configured by the reaction tube 203 and the manifold 209 . A processing chamber 201 is formed in the cylindrical hollow portion of the processing container. The processing chamber 201 is configured to accommodate a wafer 200 as a substrate. A wafer 200 is processed in the processing chamber 201 .

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

The gas supply pipes 232a to 232c are provided with mass flow controllers (MFC) 241a to 241c as flow rate controllers (flow rate control units) and valves 243a to 243c as on-off valves in this order from the upstream side of the gas flow. . Gas supply pipes 232d to 232h are connected to the gas supply pipes 232a to 232c downstream of the valves 243a to 243c, respectively. The gas supply pipes 232d-232h are provided with MFCs 241d-241h and valves 243d-243h, respectively, in this order from the upstream side of the gas flow. The gas supply pipes 232a to 232h are made of metal material such as SUS, for example.

As shown in FIG. 2, the nozzles 249a to 249c are arranged in an annular space between the inner wall of the reaction tube 203 and the wafer 200 in a plan view, along the inner wall of the reaction tube 203 from the lower part to the upper part. They are provided so as to rise upward in the arrangement direction. In other words, the nozzles 249a to 249c are provided on the sides of the wafer arrangement area in which the wafers 200 are arranged, in a region horizontally surrounding the wafer arrangement area, along the wafer arrangement area. In a plan view, the nozzle 249b is arranged so as to face an exhaust port 231a, which will be described later, in a straight line with the center of the wafer 200 loaded into the processing chamber 201 interposed therebetween. The nozzles 249a and 249c are arranged such that a straight line L passing through the center of the nozzle 249b and the exhaust port 231a is sandwiched from both sides along the inner wall of the reaction tube 203 (periphery of the wafer 200). The straight line L is also a straight line passing through the nozzle 249 b and the center of the wafer 200 . That is, it can be said that the nozzle 249c is provided on the opposite side of the straight line L from the nozzle 249a. The nozzles 249a and 249c are arranged line-symmetrically with the straight line L as the axis of symmetry. Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c is open to face the exhaust port 231a in a plan view, and is capable of supplying gas toward the wafer 200. As shown in FIG. A plurality of gas supply holes 250 a to 250 c are provided from the bottom to the top of the reaction tube 203 .

From the gas supply pipe 232a, a gas containing silicon (Si) as a main element constituting a film formed on the wafer 200 and a halogen element, that is, a halosilane-based gas is supplied through the MFC 241a, the valve 243a, and the nozzle 249a. and supplied into the processing chamber 201 . A halosilane-based gas acts as a film-forming gas, that is, as a Si source (raw material gas). Halogen elements include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), and the like. As the halosilane-based gas, for example, a chlorosilane-based gas containing Si and Cl can be used, and for example, a silicon tetrachloride (SiCl ₄ ) gas can be used.

A gas containing fluorine (F) is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b. As the fluorine-containing gas, for example, fluorine (F ₂ ) gas can be used.

A hydrogen nitride-based gas, which is a nitrogen (N)-containing gas, is supplied from the gas supply pipe 232c into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c. A hydrogen nitride-based gas acts as a film-forming gas, that is, as an N source (nitriding gas, nitriding agent). For example, ammonia (NH ₃ ) gas can be used as the hydrogen nitride-based gas.

An aminosilane-based gas containing Si and an amino group is supplied from the gas supply pipe 232g into the processing chamber 201 via the MFC 241g, the valve 243g, the gas supply pipe 232c, and the nozzle 249c.

As the aminosilane-based gas, for example, monoaminosilane (SiH ₃ R) gas, which is a raw material containing one amino group (in one molecule) in the composition formula, can be used. Here, R is an amino group in which one or two hydrocarbon groups containing one or more C atoms are coordinated to one N atom (one or both H of the amino group represented by _NH2 substituted with a hydrocarbon group containing one or more C atoms). When two hydrocarbon groups constituting a part of the amino group are coordinated to one N, the two may be the same hydrocarbon group or different hydrocarbon groups. . Moreover, the hydrocarbon group may contain an unsaturated bond such as a double bond or a triple bond. Moreover, the amino group may have a cyclic structure. Since the amino group is bonded to Si, which is the central atom of the SiH ₃ R molecule, this amino group is also called a ligand or an amino ligand.

Examples of SiH ₃ R gas include ethylmethylaminosilane (SiH ₃ [N(CH ₃ )(C ₂ H ₅ )]) gas, dimethylaminosilane (SiH ₃ [N(CH ₃ ) ₂ ]) gas, diisopropylaminosilane ( SiH ₃ [N(C ₃ H ₇ ) ₂ ]) gas, di-secondary butylaminosilane (SiH ₃ [H(C ₄ H ₉ ) ₂ ]) gas, dimethylpiperidinosilane (SiH ₃ [NC ₅ H ₈ (CH ₃ ) ₂ ]) gas and diethylpiperidinosilane (SiH ₃ [NC ₅ H ₈ (C ₂ H ₅ ) ₂ ]) gas can be used.

An oxygen (O)-containing gas is supplied from the gas supply pipe 232h into the processing chamber 201 via the MFC 241h, the valve 243h, the gas supply pipe 232a, and the nozzle 249a. The O-containing gas acts as a process gas, ie, an oxidant. Oxygen (O ₂ ) gas, for example, can be used as the O-containing gas.

From the gas supply pipes 232d to 232f, nitrogen (N ₂ ) gas as an inert gas, for example, is supplied to the processing chamber via MFCs 241d to 241f, valves 243d to 243f, gas supply pipes 232a to 232c, and nozzles 249a to 249c, respectively. 201. _N2 gas acts as purge gas, carrier gas, diluent gas, and the like.

A deposition gas supply system (source gas supply system, reaction gas supply system) is mainly composed of gas supply pipes 232a, 232c, MFCs 241a, 241c, and valves 243a, 243c. A processing gas supply system (oxygen-containing gas supply system) is mainly configured by the gas supply pipe 232h, the MFC 241h, and the valve 243h. An aminosilane-based gas supply system is mainly composed of the gas supply pipe 232g, the MFC 241g, and the valve 243g. A fluorine-containing gas supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. An inert gas supply system is mainly composed of gas supply pipes 232d to 232f, MFCs 241d to 241f, and valves 243d to 243f.

Any or all of the supply systems described above may be configured as an integrated supply system 248 in which valves 243a to 243h, MFCs 241a to 241h, and the like are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232h, and supplies 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 MFCs 241a to 241h. The flow rate adjustment operation and the like are configured to be controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integral or divided integrated unit, and can be attached/detached to/from the gas supply pipes 232a to 232h or the like in units of integrated units. It is configured so that maintenance, replacement, expansion, etc. can be performed on an integrated unit basis.

Below the side wall of the reaction tube 203, an exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided. As shown in FIG. 2, the exhaust port 231a is provided at a position facing the nozzles 249a to 249c (gas supply holes 250a to 250c) across the wafer 200 in plan view. The exhaust port 231a may be provided along the upper portion of the side wall of the reaction tube 203, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is supplied with a pressure sensor 245 as a pressure detector (pressure detector) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure regulator). , a vacuum pump 246 as an evacuation device is connected. By opening and closing the APC valve 244 while the vacuum pump 246 is operating, the inside of the processing chamber 201 can be evacuated and stopped. By adjusting the valve opening based on the pressure information detected by the pressure sensor 245, the pressure in the processing chamber 201 can be adjusted. An exhaust system is mainly composed of the exhaust pipe 231 , the APC valve 244 and the pressure sensor 245 . A vacuum pump 246 may be considered to be included in the exhaust system.

Below the manifold 209, a seal cap 219 is provided as a furnace mouth cover capable of hermetically closing the lower end opening of the manifold 209. As shown in FIG. The seal cap 219 is made of, for example, a metal material such as SUS, and is shaped like a disc. An O-ring 220 b is provided on the upper surface of the seal cap 219 as a sealing member that contacts the lower end of the manifold 209 .

Below the seal cap 219, a rotating mechanism 267 for rotating the boat 217, which will be described later, is installed. A rotating shaft 255 of the rotating mechanism 267 is made of a metal material such as SUS, and is connected to the boat 217 through the seal cap 219 . The rotating mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217 . The seal cap 219 is vertically moved up and down by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203 . The boat elevator 115 is configured as a transport device (transport mechanism) for loading and unloading (transporting) the wafer 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219 .

Below the manifold 209, a shutter 219s is provided as a furnace port cover that can airtightly close the lower end opening of the manifold 209 in a state in which the seal cap 219 is lowered and the boat 217 is carried out of the processing chamber 201. The shutter 219s is made of a metal material such as SUS, and is shaped like a disc. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that contacts the lower end of the manifold 209. As shown in FIG. The opening/closing operation (elevating operation, rotating operation, etc.) of the shutter 219s is controlled by the shutter opening/closing mechanism 115s.

The boat 217 as a substrate support supports a plurality of wafers 200, for example, 25 to 200 wafers 200, in a horizontal posture, aligned vertically with their centers aligned with each other, and supported in multiple stages. It is configured to be spaced and arranged. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, a plurality of heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported.

A temperature sensor 263 as a temperature detector is installed in the reaction tube 203 . By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 has a desired temperature distribution. A temperature sensor 263 is provided along the inner wall of the reaction tube 203 .

As shown in FIG. 3, a 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. It is The RAM 121b, storage device 121c, and I/O port 121d are configured to exchange data with the CPU 121a via an internal bus 121e. An input/output device 122 configured as, for example, a touch panel or the like is connected to the controller 121 .

The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), or the like. In the storage device 121c, a control program for controlling the operation of the substrate processing apparatus, a process recipe describing procedures and conditions for substrate processing, which will be described later, and the like are stored in a readable manner. The process recipe functions as a program in which the controller 121 executes each procedure in substrate processing, which will be described later, and is combined so as to obtain a predetermined result. Hereinafter, process recipes, control programs, and the like are collectively referred to simply as programs. A process recipe is also simply referred to as a recipe. When the term "program" is used in this specification, it may include only a single recipe, only a single control program, or both. The RAM 121b is configured as a memory area (work area) in which programs and data read by the CPU 121a are temporarily held.

The I/O port 121d includes the MFCs 241a to 241h, valves 243a to 243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotating mechanism 267, boat elevator 115, shutter opening/closing mechanism 115s, and the like. It is connected to the.

The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read recipes from the storage device 121c in response to input of operation commands from the input/output device 122 and the like. The CPU 121a adjusts the flow rate of various gases by the MFCs 241a to 241h, the opening and closing operations of the valves 243a to 243h, the opening and closing operations of the APC valve 244, and the pressure adjustment by the APC valve 244 based on the pressure sensor 245 so as to follow the content of the read recipe. operation, starting and stopping of the vacuum pump 246, temperature adjustment operation of the heater 207 based on the temperature sensor 263, rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, elevation operation of the boat 217 by the boat elevator 115, shutter opening/closing mechanism 115s It is configured to control the opening/closing operation of the shutter 219s by means of.

The controller 121 can be configured by installing the above-described program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, a semiconductor memory such as a USB memory, and the like. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are also 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, may include only the external storage device 123 alone, or may include both of them. The program may be provided to the computer using communication means such as the Internet or a dedicated line without using the external storage device 123 .

(2) Substrate Processing Process Using the substrate processing apparatus described above, as one step of the manufacturing process of a semiconductor device, a substrate is selectively formed on the surface of a specific underlayer among a plurality of types of underlayers exposed on the surface of the wafer 200 as a substrate. A processing sequence example of selective growth (selective film formation) for growing and forming a film will be described mainly with reference to FIGS. 4 and 5(a) to 5(g). In the following description, the controller 121 controls the operation of each component of the substrate processing apparatus.

In the processing sequence shown in FIG.
On the surface, an O-free first base (base 200a) containing a silicon nitride film (SiN film), a second O-containing base (base 200b) containing a silicon oxide film (SiO film), and single crystal silicon By supplying O ₂ gas as a processing gas to the exposed wafer 200 with a third underlayer (underlayer 200c) containing (Si) and not containing O and N, a SiO 2 gas is supplied as a protective film 200e to the surface of the underlayer 200c. A step of forming a membrane;
By supplying SiH ₃ R gas as an aminosilane-based gas to the wafer 200 after forming the protective film 200e on the surface of the underlayer 200c, each surface of the underlayer 200b and the protective film 200e contained in the SiH ₃ R gas A step B of adsorbing Si;
By supplying F ₂ gas as a fluorine-containing gas to the wafer 200 after adsorbing Si on the respective surfaces of the underlayer 200b and the protective film 200e, Si was adsorbed on the respective surfaces of the underlayer 200b and the protective film 200e. a step _C of reacting Si and F2 gas to modify the surfaces of the underlayer 200b and the protective film 200e;
By supplying SiCl ₄ gas and NH ₃ gas as film-forming gases to the wafer 200 after modifying the respective surfaces of the underlayer 200b and the protective film 200e, a Si film is formed on the surface of the underlayer 200a. and a step D of selectively forming a SiN film, which is a film containing N, is performed.

Note that FIG. 4 shows that in step D, a cycle of performing step D1 of supplying SiCl ₄ gas to the wafer 200 and step D2 of supplying NH ₃ gas to the wafer 200 non-simultaneously is repeated a predetermined number of times (n times, n is an integer equal to or greater than 1).

In this specification, the processing sequence described above may also be indicated as follows for convenience. The same notation is used also in the description of other aspects below.

_O2 → _SiH3R →F2→ _{( SiCl4} → _NH3 )×n→SiN

When the term "wafer" is used in this specification, it may mean the wafer itself, or it may mean a laminate of a wafer and a predetermined layer or film formed on its surface. In this specification, the term "wafer surface" may mean the surface of the wafer itself or the surface of a predetermined layer formed on the wafer. In the present specification, the term "formation of a predetermined layer on a wafer" means that a predetermined layer is formed directly on the surface of the wafer itself, or a layer formed on the wafer, etc. It may mean forming a given layer on top of. The use of the term "substrate" in this specification is synonymous with the use of the term "wafer".

(wafer charge and boat load)
When the boat 217 is loaded with a plurality of wafers 200 (wafer charge), the shutter 219s is moved by the shutter opening/closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in FIG. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and loaded 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.

As shown in FIG. 5A, on the surface of the wafer 200, a plurality of types of underlayers, here, as an example, an underlayer 200a including a SiN film as a nitride film that is an O-free film, that is, a non-oxidized film, and an O The underlayer 200b containing the SiO film as the containing film, that is, the oxide film, and the underlayer 200c containing single-crystal Si as the substance not containing O and N are exposed in advance. That is, here, the underlayer 200a is composed of a SiN film that is an insulating material (insulator), the underlayer 200b is composed of a SiO film that is an insulating material (insulator), and the underlayer 200c is a single crystal that is a semiconductor material. An example made of Si is shown. In addition, as shown in FIG. 5A, when a natural oxide film 200d is formed on the surface of the wafer 200, the wafer 200 is treated with diluted hydrofluoric acid (DHF) in advance, that is, before boat loading. ) A cleaning process (DHF cleaning) using an aqueous solution, that is, an aqueous hydrogen fluoride (HF) solution is performed to remove the natural oxide film 200d formed on the surface of the wafer 200 (natural oxide film removal). Specifically, the wafer 200 is subjected to DHF cleaning to remove the natural oxide film 200d formed on the surface of the underlayer 200a as shown in FIG. The material of 200a, that is, the SiN film is exposed. As a result, the surface of the underlayer 200a can be uniformly processed in step D, which will be described later. When removing the natural oxide film 200d formed on the surface of the underlayer 200a, the natural oxide film 200d formed on the surface of the underlayer 200c exposed on the surface of the wafer 200 is also removed, and the material of the underlayer 200c is removed at the outermost surface of the underlayer 200c. That is, the single-crystal Si is also uncovered and exposed. As a result, the surface of the underlayer 200c can be uniformly treated in step A, which will be described later.

(pressure regulation and temperature regulation)
The inside of the processing chamber 201, that is, the space in which the wafer 200 exists is evacuated (reduced pressure) by the vacuum pump 246 so that it has a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Also, the wafer 200 in the processing chamber 201 is heated by the heater 207 so as to reach a desired processing temperature. At this time, the energization state of the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Also, the rotation of the wafer 200 by the rotation mechanism 267 is started. The evacuation of the processing chamber 201 and the heating and rotation of the wafer 200 continue at least until the processing of the wafer 200 is completed.

(selective growth)
After that, the following steps A to D are sequentially performed.

[Step A]
In this step, the O ₂ gas is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 having the underlying surfaces 200a, 200b, and 200c exposed as shown in FIG. 5B.

Specifically, the valve 243h is opened to allow O ₂ gas to flow into the gas supply pipe 232h. The O ₂ gas has its flow rate adjusted by the MFC 241h, is supplied into the processing chamber 201 through the gas supply pipe 232a and the nozzle 249a, and is exhausted from the exhaust port 231a. At this time, O ₂ gas is supplied to the wafer 200 (O ₂ gas supply). At this time, the valves 243e and 243f are opened to supply _N2 gas into the processing chamber 201 through the nozzles 249b and 249c, respectively. The supply of _N2 gas may be disabled.

The processing conditions in this step are as follows:
O ₂ gas supply flow rate: 10-10000 sccm, preferably 100-10000 sccm
O ₂ gas supply time: 1 to 180 minutes, preferably 1 to 60 minutes N ₂ gas supply flow rate (per gas supply pipe): 0 to 10000 sccm, preferably 100 to 10000 sccm
Treatment temperature: room temperature (25°C) to 600°C, preferably 50 to 550°C
Treatment pressure: 1 to atmospheric pressure (101325 Pa), preferably 10 to 5000 Pa, more preferably 100 to 1000 Pa
are exemplified. The conditions described here are conditions under which the underlayer 200c is oxidized without oxidizing the surface of the underlayer 200a.

In addition, the expression of a numerical range such as "1 to 101325 Pa" in this specification means that the lower limit and the upper limit are included in the range. Therefore, for example, "1 to 101325 Pa" means "1 Pa or more and 101325 Pa or less". The same applies to other numerical ranges.

By supplying O ₂ gas to the wafer 200 under the above conditions, as shown in FIG. ) can be oxidized. By oxidizing the surface of the underlayer 200c, a SiO film is formed as the protective film 200e on the surface of the underlayer 200c. At this time, since the underlayer 200b is composed of the SiO film, the surface of the underlayer 200b is not oxidized, and the protective film 200e is not newly formed on the surface. Such selective (preferential) oxidation is possible because the processing conditions in this step are the conditions under which the surface of the underlayer 200a is not oxidized, that is, the oxide film (SiO film or SiON film) is not formed on the surface of the underlayer 200a. This is because the conditions are such that they are not formed. In this step, dry oxidation is performed under conditions in which the surface of the underlayer 200a is not oxidized, so that only the surface of the underlayer 200c is selectively oxidized. It becomes possible to form In addition, in this step, by oxidizing the surface of the underlayer 200c under pressure conditions below atmospheric pressure (in a vacuum atmosphere, under a reduced pressure atmosphere), the film thickness controllability of the protective film 200e formed on the surface of the underlayer 200c, It becomes possible to improve film thickness uniformity.

The protective film 200e formed on the surface of the underlayer 200c functions as a film that protects the underlayer 200c when F2 gas is supplied in step _C described later. When the F ₂ gas contacts the surface of the underlayer 200c in step C, which will be described later, the surface of the underlayer 200c is etched and may be damaged by etching. By forming the protective film 200e on the surface of the underlayer 200c, it is possible to prevent the F ₂ gas from contacting the surface of the underlayer 200c in step C, thereby suppressing the etching of the surface of the underlayer 200c. It is possible to suppress etching damage to the surface. Note that the protective film 200e does not adversely affect the processing in steps B and C. As shown in FIG.

The film thickness of the protective film 200e formed in this step is about 10 Å, which is thinner than the film thickness of the natural oxide film 200d formed on the surface of the underlayer 200c before DHF cleaning. Even if the thickness of the protective film 200e is small, the film thickness uniformity of the protective film 200e is much higher _than the film thickness uniformity of the natural oxide film. It is possible to sufficiently suppress the contact of the _F2 gas with the surface of the underlayer 200c.

After forming the protective film 200e on the surface of the underlayer 200c, the valve 243h is closed to stop the supply of the O ₂ gas into the processing chamber 201 . Then, the inside of the processing chamber 201 is evacuated, and gas and the like remaining in the processing chamber 201 are removed from the inside of the processing chamber 201 . At this time, the valves 243d to _243f are opened to supply N.sub.2 gas into the processing chamber 201 through the nozzles 249a to 249c. The N ₂ gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging the inside of the processing chamber 201 (purge).

As the O-containing gas, in addition to O ₂ gas, nitrous oxide (N ₂ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ₂ ) gas, ozone (O ₃ ) gas, water vapor (H ₂ O gas), carbon monoxide (CO) gas, carbon dioxide (CO ₂ ) gas, and other O-containing gases can be used.

As the inert gas, rare gases such as Ar gas, He gas, Ne gas, and Xe gas can be used in addition to _N2 gas. This point also applies to each step described later.

[Step B]
After step A is finished, SiH ₃ R gas is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 after forming the protective film 200e on the surface of the underlayer 200c.

Specifically, the valve 243g is opened to allow the SiH ₃ R gas to flow into the gas supply pipe 232g. The SiH ₃ R gas has its flow rate adjusted by the MFC 241g, is supplied into the processing chamber 201 through the gas supply pipe 232c and the nozzle 249c, and is exhausted from the exhaust port 231a. At this time, SiH ₃ R gas is supplied to the wafer 200 (SiH ₃ R gas supply). At this time, the valves 243d and 243e are opened to supply _N2 gas into the processing chamber 201 through the nozzles 249a and 249b, respectively. The supply of _N2 gas may be disabled.

The processing conditions in this step are as follows:
SiH ₃ R gas supply flow rate: 1 to 2000 sccm, preferably 1 to 500 sccm
SiH ₃ R gas supply time: 1 second to 60 minutes N ₂ gas supply flow rate (per gas supply pipe): 0 to 10000 sccm
Treatment temperature: room temperature (25°C) to 600°C, preferably room temperature to 450°C
Treatment pressure: 1 to 2000 Pa, preferably 1 to 1000 Pa
are exemplified. The conditions described here are conditions under which the SiH ₃ R gas does not undergo vapor phase decomposition (thermal decomposition) within the processing chamber 201 . The underlayer 200b and the protective film 200e have surfaces terminated with hydroxyl groups (OH) over the entire area (entire surface). The underlayer 200a has a surface where many regions are not OH-terminated, that is, a surface where some regions are OH-terminated.

By supplying the SiH ₃ R gas to the wafer 200 under the conditions described above _, as shown in FIG. , Si contained in the SiH ₃ R gas can be selectively (preferentially) adsorbed on the surface of the underlayer 200b. At this time, it is possible to selectively (preferentially) adsorb Si contained in the SiH ₃ R gas also on the surface of the protective film 200e. At this time, Si contained in the SiH ₃ R gas may be adsorbed on a part of the surface of the underlayer 200a. will be less than Such selective (preferential) adsorption is possible because the processing conditions in this step are conditions under which the SiH ₃ R gas does not undergo vapor phase decomposition within the processing chamber 201 . Further, while the surfaces of the underlayer 200b and the protective film 200e are OH-terminated over the entire surface, many regions of the surface of the underlayer 200a are not OH-terminated (a partial region of the surface is OH-terminated). is there). In this step, since the SiH ₃ R gas does not undergo vapor phase decomposition in the processing chamber 201, Si contained in SiH ₃ R does not deposit multiple times on the respective surfaces of the underlayers 200a and 200b and the protective film 200e. In this step, the OH termination formed on the entire surface of each of the underlayer 200b and the protective film 200e reacts with SiH ₃ R, and Si contained in SiH ₃ R reacts with the underlayer 200b and the protective film 200e. Chemisorb across their respective surfaces. On the other hand, since OH termination does not exist in many regions of the surface of the underlayer 200a, Si contained in SiH ₃ R does not chemisorb to many regions. However, the OH termination formed on a partial region of the surface of the underlayer 200a reacts with SiH ₃ R, and Si contained in SiH ₃ R may be chemically adsorbed on that partial region. When Si contained in SiH ₃ R chemically adsorbs to the surface of the base, the chemical adsorption occurs in a state where H is bonded to Si.

When the SiH ₃ R gas is continuously supplied for a predetermined time, chemical adsorption of Si on the surfaces of the underlayer 200b and the protective film 200e is saturated. That is, the chemical adsorption of Si to the surfaces of the underlayer 200b and the protective film 200e is self-limited. In other words, when one Si layer is formed on each surface of the underlayer 200b and the protective film 200e, Si is no longer chemisorbed onto the respective surfaces of the underlayer 200b and the protective film 200e. As a result, the amounts of Si adsorbed on the surfaces of the underlayer 200b and the protective film 200e are substantially uniform over the entire surfaces of the underlayer 200b and the protective film 200e.

After selectively adsorbing Si on the surfaces of the underlayer 200b and the protective film 200e, the valve 243g is closed to stop the supply of the SiH ₃ R gas into the processing chamber 201 . Then, the gas or the like remaining in the processing chamber 201 is removed from the processing chamber 201 by the same processing procedure as the purge in step A. FIG.

As the aminosilane-based gas, in addition to the above-mentioned monoaminosilane gas containing only one amino group in one molecule, diaminosilane (SiH ₂ RR′) gas containing two amino groups in one molecule, A triaminosilane (SiHRR'R'') gas containing three amino groups can be used.

As the aminosilane-based gas, an aminosilane compound represented by the following general formula [1] can be used.

SiA _x [(NB ₂ ) _(4−x) ] [1]

In formula [1], A represents a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, or an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group or a butoxy group. The alkyl group may be not only a linear alkyl group but also a branched alkyl group such as isopropyl group, isobutyl group, secondary butyl group and tertiary butyl group. The alkoxy group may be not only a linear alkoxy group but also a branched alkoxy group such as an isopropoxy group and an isobutoxy group. B represents a hydrogen atom or an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group. The alkyl group may be not only a linear alkyl group but also a branched alkyl group such as isopropyl group, isobutyl group, secondary butyl group and tertiary butyl group. A plurality of A's may be the same or different, and two B's may be the same or different. x is an integer of 1-3.

[Step C]
After step B is completed, F2 gas is supplied to the wafer ₂₀₀ in the processing chamber 201, that is, the wafer 200 after selectively adsorbing Si to the respective surfaces of the underlayer 200b and the protective film 200e.

Specifically, the valve 243b is opened to allow _F2 gas to flow into the gas supply pipe 232b. _The flow rate of the F2 gas is adjusted by the MFC 241b, supplied into the processing chamber 201 through the nozzle 249b, and exhausted through the exhaust port 231a. At this time, F2 gas is supplied to the wafer _{200 (} F2 gas supply). At this time, the valves 243d and 243f are opened to supply _N2 gas into the processing chamber 201 through the nozzles 249a and 249c, respectively. The supply of _N2 gas may be disabled.

The processing conditions in this step are as follows:
F ₂ gas supply flow rate: 1 to 2000 sccm, preferably 1 to 500 sccm
F ₂ gas supply time: 1 second to 60 minutes Treatment temperature: room temperature to 550°C, preferably room temperature to 450°C
are exemplified. Other conditions are the same as the processing conditions in step B. The conditions described here are conditions under which the surfaces of the underlayer 200b and the protective film 200e are not etched, and conditions under which the surfaces of the underlayer 200b and the protective film 200e are modified (F termination) as described later. is.

By supplying the F2 gas to the wafer ₂₀₀ under the above conditions, the Si adsorbed _on the surfaces of the underlayer 200b and the protective film 200e react with the F2 gas to form the underlayer 200b and the protective film 200e. It becomes possible to modify the surface of each without etching. At this time, since the surface of the underlayer 200c is protected by the protective film 200e, it is possible to prevent contact of the F ₂ gas with the surface of the underlayer 200c, thereby avoiding etching damage to the surface of the underlayer 200c. becomes possible. The underlayer 200b and protective film 200e after modification have F-terminated (SiF-terminated) surfaces. Note that when focusing on the atoms existing on the outermost surfaces of the underlayer 200b and the protective film 200e after modification, the underlayer 200b and the protective film 200e can be said to have F-terminated surfaces, respectively. Further, when focusing on the atoms present on the outermost surfaces of the modified underlayer 200b and the protective film 200e and the atoms bonded to the atoms, the underlayer 200b and the protective film 200e are each SiF-terminated. can be said to have a smoothed surface. In this specification, for the sake of convenience, the former name is mainly used. Since the surfaces of the underlayer 200b and the protective film 200e are F-terminated, the film forming reaction does not proceed on the surfaces of the underlayer 200b and the protective film 200e in step D, which will be described later. More precisely, it is possible to lengthen the time until film formation reaction occurs, that is, the incubation time. In addition, when the organic component contained in SiH ₃ R remains on the respective surfaces of the underlayer 200b and the protective film 200e, Si and F ₂ gas adsorbed on the respective surfaces of the underlayer 200b and the protective film 200e When reacting with , the organic components are removed from the respective surfaces of the underlayer 200b and the protective film 200e.

As shown in FIG. 5E, in this step, it is possible to selectively (preferentially) modify the surfaces of the underlayer 200b and the protective film 200e while suppressing the modification of the surface of the underlayer 200a. becomes. At this time, part of the surface of the underlayer 200a may be modified, but the amount of modification is smaller than the amounts of modification of the respective surfaces of the underlayer 200b and the protective film 200e. Such selective (preferential) modification is possible because, after performing step B, Si is not adsorbed on many regions of the surface of the underlayer 200a, whereas Si is not adsorbed on the underlayer 200b and the protective film. This is because Si is adsorbed on the entire surface of each of 200e. In many regions of the surface of the underlayer 200a, since Si is not adsorbed, the reaction between Si and F2 does not proceed, and as a result, F terminations _are not formed in many regions. However, as described above, Si may be adsorbed on a partial region of the surface of the underlayer 200a, in which case an F termination may be formed on that partial region. On the other hand, on the surfaces of the underlayer 200b and the protective film 200e, Si adsorbed to the surface reacts with F2 over the entire surface to generate F _- containing radicals. , very stable F terminations (SiF terminations) are formed across their surfaces. F-containing radicals include F, SiF, SiF ₂ , SiF ₃ , SiHF, SiH ₂ F, SiHF ₂ and the like.

As described above, the amount of Si adsorbed onto the underlayer 200b and the protective film 200e in step B is substantially uniform over the entire surfaces of the underlayer 200b and the protective film 200e. Therefore, in this step, the amounts of F-containing radicals generated on the surfaces of the underlayer 200b and the protective film 200e are substantially uniform over the entire surface. As a result, the modification of the underlayer 200b and the protective film 200e described above progresses substantially uniformly over the entire surfaces thereof.

In addition, in many regions of the surface of the underlayer 200a, since Si is not adsorbed as described above, the reaction between Si and F2 does not proceed, F _- containing radicals are not generated, and many regions are reformed. will not be questioned. However, when Si is adsorbed on a partial region of the surface of the underlayer 200a, Si reacts with F2 in the partial region to generate F _- containing radicals, and the partial region is As mentioned above, it may be modified. As a result, the surface of the underlayer 200a is hardly damaged by etching, and adsorption sites are maintained in many regions of the surface.

After selectively modifying the surfaces of the underlayer 200b and the protective film 200e out of the underlayers 200a and 200b and the protective film 200e, the valve 243b is closed and the supply of _F2 gas into the processing chamber 201 is stopped. Then, the gas or the like remaining in the processing chamber 201 is removed from the processing chamber 201 by the same processing procedure as the purge in step A. FIG.

As the fluorine-containing gas, in addition to F ₂ gas, chlorine trifluoride (ClF ₃ ) gas, chlorine fluoride gas (ClF) gas, F ₂ + nitrogen oxide (NO) gas, ClF + NO gas, nitrogen trifluoride (NF ₃ ) gas, tungsten hexafluoride (WF ₆ ) gas, nitrosyl fluoride (FNO) gas, or a mixture of these gases can be used.

[Step D]
After step C is finished, SiCl ₄ gas and NH ₃ gas are supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 after modifying the surfaces of the underlayer 200b and the protective film 200e. In this step, steps D1 and D2 are sequentially performed.

[Step D1]
In this step, SiCl is applied to the wafer 200 in the processing chamber 201, that is, the wafer 200 after selectively modifying the surfaces of the underlayer 200b and the protective film 200e among the underlayers 200a and 200b and the protective film 200e. ₄ supply gas.

Specifically, the valve 243a is opened to flow SiCl ₄ gas into the gas supply pipe 232a. The SiCl ₄ gas is flow-controlled by the MFC 241a, supplied into the processing chamber 201 through the nozzle 249a, and exhausted through the exhaust port 231a. At this time, SiCl ₄ gas is supplied to the wafer 200 (SiCl ₄ gas supply). At this time, the valves 243e and 243f may be opened to supply the _N2 gas into the processing chamber 201 through the nozzles 249b and 249c, respectively.

The processing conditions in this step are as follows:
SiCl ₄ gas supply flow rate: 1-2000 sccm, preferably 10-1000 sccm
SiCl ₄ gas supply time: 1-180 seconds, preferably 10-120 seconds Processing temperature: 350-600°C, preferably 400-550°C
Treatment pressure: 1 to 2000 Pa, preferably 10 to 1333 Pa
are exemplified. Other processing conditions are the same as the processing conditions in step B.

By supplying SiCl ₄ gas to the wafer 200 under the above conditions, a Si-containing layer containing Cl is formed on the surface of the underlayer 200a including the unmodified regions of the underlayers 200a and 200b and the protective film 200e. is formed. That is, the Si-containing layer containing Cl is formed starting from the unmodified region of the underlayer 200a, that is, the region where the adsorption sites are maintained. The Si-containing layer containing Cl is formed by physical adsorption or chemical adsorption of SiCl ₄ on the surface of the underlayer 200a, chemical adsorption of a substance (SiCl _x ) obtained by partially decomposing SiCl ₄ , and deposition of Si by thermal decomposition of SiCl ₄ . etc. The Si-containing layer containing Cl may be an adsorption layer (physisorption layer or chemisorption layer) of SiCl ₄ or SiCl _x , or may be a deposited layer of Si containing Cl. In this specification, the Si-containing layer containing Cl is also simply referred to as the Si-containing layer.

In this step, it is possible to selectively form the Si-containing layer on the surface of the underlayer 200a while suppressing the formation of the Si-containing layer on the respective surfaces of the underlayer 200b and the protective film 200e. In addition, when the modification of the surfaces of the underlayer 200b and the protective film 200e becomes insufficient for some reason, a very slight Si-containing layer is formed on the surfaces of the underlayer 200b and the protective film 200e. However, even in this case, the thickness of the Si-containing layer formed on each surface of the underlayer 200b and the protective film 200e is the thickness of the Si-containing layer formed on the surface of the underlayer 200a. Much thinner than it is thick. The selective formation of such a Si-containing layer is possible because the F termination present on the surface of each of the underlayer 200b and the protective film 200e allows the Si-containing layer to be formed on the surface of each of the underlayer 200b and the protective film 200e. This is because it acts as a factor that inhibits layer formation (adsorption of Si), that is, as an inhibitor. Note that the F terminations present on the respective surfaces of the underlayer 200b and the protective film 200e are stably maintained without disappearing even when this step is carried out.

After the Si-containing layer is formed on the surface of the underlayer 200a, the valve 243a is closed and the supply of _SiCl4 gas into the processing chamber 201 is stopped. Then, the gas remaining in the processing chamber 201 is removed from the processing chamber 201 (purge) by the same processing procedure as the purge in step A. FIG.

In addition to SiCl ₄ gas, the raw material gas (film formation gas) includes monochlorosilane (SiH ₃ Cl, abbreviation: MCS) gas, dichlorosilane (SiH ₂ Cl ₂ , abbreviation: DCS) gas, trichlorosilane (SiHCl ₃ , abbreviation: DCS) gas. :TCS) gas, hexachlorodisilane (Si ₂ Cl ₆ , abbreviation: HCDS) gas, octachlorotrisilane (Si ₃ Cl ₈ , abbreviation: OCTS) gas, chlorosilane-based gas such as tetrabromosilane (SiBr ₄ ) gas, etc. bromosilane-based gas, and iodosilane-based gas such as tetraiodosilane (SiI ₄ ) gas can be used.

[Step D2]
In this step, NH ₃ gas is supplied to the wafer 200 in the processing chamber 201, that is, the Si-containing layer formed on the surface of the underlayer 200a.

Specifically, the valve 243c is opened to allow the NH ₃ gas to flow into the gas supply pipe 232c. The NH ₃ gas has its flow rate adjusted by the MFC 241c, is supplied into the processing chamber 201 through the nozzle 249c, and is exhausted through the exhaust port 231a. At this time, NH ₃ gas is supplied to the wafer 200 (NH ₃ gas supply). At this time, the valves 243d and 243e may be opened to supply the _N2 gas into the processing chamber 201 through the nozzles 249a and 249b, respectively.

The processing conditions in this step are as follows:
NH ₃ gas supply flow rate: 10-10000 sccm
NH ₃ gas supply time: 1-60 seconds, preferably 5-50 seconds Treatment pressure: 1-4000 Pa, preferably 1-1333 Pa
are exemplified. Other processing conditions are the same as the processing conditions in step B.

By supplying NH ₃ gas to the wafer 200 under the above conditions, at least part of the Si-containing layer formed on the surface of the underlayer 200a is nitrided. By nitriding the Si-containing layer, a layer containing Si and N, that is, a silicon nitride layer (SiN layer) is formed on the surface of the underlayer 200a. Impurities such as Cl contained in the Si-containing layer when forming the SiN layer form a gaseous substance containing at least Cl in the process of the nitridation reaction of the Si-containing layer by _NH3 gas. discharged from As a result, the SiN layer becomes a layer containing fewer impurities such as Cl than the Si-containing layer formed in step D1. The respective surfaces of base 200b and protective film 200e are maintained without being nitrided even when this step is performed. That is, the respective surfaces of the underlayer 200b and the protective film 200e are stably maintained as F-terminated without being nitrided (NH-terminated).

After the SiN layer is formed on the surface of the underlayer 200a, the valve 243c is closed and the supply of _NH3 gas into the processing chamber 201 is stopped. Then, the gas remaining in the processing chamber 201 is removed from the processing chamber 201 (purge) by the same processing procedure as the purge in step A. FIG.

As the reaction gas (film formation gas), in addition to _NH3 gas, for example, hydrogen nitride gases such as diazene _{( N2H2} ) gas _, hydrazine _{( N2H4} ) gas, and _N3H8 gas may be used. can be done.

[Implemented a predetermined number of times]
By performing a predetermined number of cycles (n times, where n is an integer equal to or greater than 1) in which steps D1 and D2 described above are performed asynchronously, that is, without synchronization, the surface of the wafer 200 is formed as shown in FIG. The SiN film can be selectively formed on the surface of the underlayer 200a among the underlayers 200a and 200b and the protective film 200e exposed to the surface. The above cycle is preferably repeated multiple times. That is, the thickness of the SiN layer formed per cycle is made thinner than the desired film thickness, and the above-mentioned cycles are repeated until the film thickness of the film formed by stacking the SiN layers reaches the desired film thickness. is preferably repeated multiple times.

It should be noted that, when performing steps D1 and D2, the F terminations present on the respective surfaces of the underlayer 200b and the protective film 200e are maintained without being extinguished. No SiN film is formed on each surface of the film 200e. However, if for some reason the surface modification of the underlayer 200b and the protective film 200e becomes insufficient, a very small amount of SiN film is formed on the surfaces of the underlayer 200b and the protective film 200e. However, even in this case, the thickness of the SiN film formed on each surface of the underlayer 200b and the protective film 200e is equal to the thickness of the SiN film formed on the surface of the underlayer 200a. much thinner in comparison. In the present specification, “selectively forming a SiN film on the surface of the underlayer 200a” of the underlayers 200a and 200b and the protective film 200e means that the SiN film is completely formed on the respective surfaces of the underlayer 200b and the protective film 200e. This includes not only the case of not forming the SiN film, but also the case of forming a very thin SiN film on each surface of the underlayer 200b and the protective film 200e as described above.

(After-purge and return to atmospheric pressure)
After selective formation of the SiN film on the underlayer 200a is completed, N ₂ gas as a purge gas is supplied into the processing chamber 201 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 gas remaining in the processing chamber 201 and reaction by-products are removed from the inside of the processing chamber 201 (afterpurge). After that, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure recovery).

(boat unload and wafer discharge)
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 unloaded from the reaction tube 203 from the lower end of the manifold 209 while being supported by the boat 217 (boat unloading). After the boat is unloaded, 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 closed). The processed wafers 200 are carried out of the reaction tube 203 and then taken out from the boat 217 (wafer discharge).

Note that, as shown in FIG. 5G, the F terminations present on the respective surfaces of the underlayer 200b and the protective film 200e are exposed to a predetermined reactant, specifically dissociates by reacting with atmospheric moisture (H ₂ O). That is, by exposing the processed wafer 200 to the atmosphere, the F termination existing on the respective surfaces of the underlayer 200b and the protective film 200e can be removed. By removing the F termination from the surface of each of the underlayer 200b and the protective film 200e, the surface state of each of the underlayer 200b and the protective film 200e is reset. It is possible to proceed with the film formation process on the .

(3) Effects of this aspect According to this aspect, one or more of the following effects can be obtained.

(a) By performing steps A to D, the SiN film can be selectively formed on the surface of the underlayer 200a among the underlayers 200a, 200b, and 200c exposed on the surface of the wafer 200. FIG. As a result, for example, when fabricating a semiconductor device, it is possible to simplify the steps such as omitting the patterning process including photolithography. As a result, it is possible to improve productivity of semiconductor devices and reduce manufacturing costs.

(b) By forming a SiO film as a protective film 200e on the surface of the underlayer 200c in step A, in step C, the surface of the underlayer 200c is not contacted with the F ₂ gas, so that etching damage to the surface of the underlayer 200c occurs. can be suppressed. That is, in step C, it is possible to modify the surfaces of the underlayer 200b and the protective film 200e while suppressing etching damage to the underlayer 200c due to the F ₂ gas.

Here, it is conceivable to use the natural oxide film (SiO film) formed on the surface of the underlayer 200c before DHF cleaning as a protective film. However, since the film thickness of the natural oxide film is non-uniform, when the natural oxide film is used as the protective film, in step C, the F ₂ gas contacts the underlayer 200c at a portion where the natural oxide film is thin, The surface of the underlayer 200c may be etched and damaged by etching.

(c) Since the film thickness of the protective film 200e is as thin as about 10 Å, it may not be necessary to remove the protective film 200e after selective growth is completed. In this case, the manufacturing process of the semiconductor device can be simplified, the productivity of the semiconductor device can be improved, and the manufacturing cost can be reduced. However, if the SiO film formed as the protective film 200e affects the characteristics of the device, it is preferable to remove the protective film 200e.

(d) Before performing step A, DHF cleaning is performed to remove the natural oxide film 200d formed on the surface of the underlayer 200a, and the surface of the underlayer 200a is exposed. It is possible to form a SiN film with high film thickness uniformity on the surface of the . In step A, the surface of the underlayer 200c is uniformly oxidized by removing the natural oxide film 200d formed on the surface of the underlayer 200c and exposing the surface of the underlayer 200c. It becomes possible to form the protective film 200e with high film thickness uniformity.

(e) In step B, the amount of Si selectively (preferentially) adsorbed onto the underlayer 200b and the protective film 200e is made substantially uniform over the entire surfaces of the underlayer 200b and the protective film 200e. becomes possible. As a result, in step C, it is possible to substantially uniformly modify the entire surfaces of the underlayer 200b and the protective film 200e. As a result, in step D, the formation of the SiN film on the underlayer 200b and the protective film 200e can be substantially uniformly and reliably inhibited over the entire surfaces thereof. That is, it becomes possible to enhance the selectivity in selective growth.

(f) After performing step D, by exposing the processed wafer 200 to the atmosphere, it is possible to eliminate F terminations as inhibitors existing on the respective surfaces of the underlayer 200b and the protective film 200e. In this way, since the F termination can be easily removed, there is no need to provide a separate process for removing the inhibitor, and the manufacturing process of the semiconductor device can be simplified, the productivity of the semiconductor device can be improved, and the manufacturing cost can be reduced. can be reduced.

(g) Since at least one of steps A to D, preferably each of steps A to D, is performed in a non-plasma atmosphere, plasma damage to the wafer 200 can be avoided, and the present method It is also possible to apply it to the process where there is concern about plasma damage.

(h) The above effects are obtained when using an oxygen-containing gas other than _O2 gas, when using an aminosilane-based gas other than _SiHR3 gas, when using a fluorine _- containing gas other than F2 gas, or when using _SiCl4 gas. Similar results can be obtained when using a raw material gas other than NH 3 gas, when using a reaction gas other than NH ₃ gas, or when using an inert gas other than N ₂ gas.

<Other aspects of the present disclosure>
Aspects of the present disclosure have been specifically described above. However, the present disclosure is not limited to the embodiments described above, and can be modified in various ways without departing from the scope of the present disclosure.

In the above-described aspect, in step B, by supplying an aminosilane-based gas to the wafer 200, Si is selectively adsorbed on the respective surfaces of the underlayer 200b and the protective film 200e, and in step C, the wafer 200 On the other hand, by supplying the F-containing gas, Si adsorbed on the surfaces of the underlayer 200b and the protective film 200e react with the F-containing gas, thereby etching the surfaces of the underlayer 200b and the protective film 200e. Although an example in which the material is modified without being used has been described, the present disclosure is not limited to such an embodiment. For example, in step C, F-containing radicals are generated by supplying an F-containing gas in an atmosphere in which a pseudo catalyst exists, and the F-containing radicals thus generated are used to form the underlayer 200b and the protective film 200e. Each surface may be modified without etching. That is, in step C, F-containing radicals are generated by supplying the F-containing gas into the processing chamber 201 containing the pseudo-catalyst, and the radicals thus generated are supplied to the surface of the wafer 200. Thus, the surfaces of the underlayer 200b and the protective film 200e among the underlayers 200a and 200b and the protective film 200e may be selectively (preferentially) modified without being etched. In this case, step B can be omitted.

Here, the pseudo-catalyst is a substance that promotes the decomposition of the F-containing gas and the generation of F-containing radicals from the F-containing gas. The pseudo-catalytic action produced by bringing the F-containing gas into contact with the pseudo-catalyst promotes the generation of F-containing radicals from the F-containing gas, making it possible to efficiently produce F-containing radicals.

As the pseudo-catalyst, for example, a solid Si whose outermost surface is not covered with a natural oxide film (SiO film), that is, a Si member whose outermost surface is exposed and bare Si material can be used. As such a member, for example, a wafer made of Si from which a native oxide film formed on the outermost surface has been removed by DHF cleaning or the like, for example, a bare Si wafer (hereinafter referred to as a bare wafer) can be used. A natural oxide film is formed on the outermost surface of the bare wafer stored in the atmosphere, and the Si material is not exposed on the outermost surface, and the bare wafer is used as a pseudo catalyst as it is. I can't. In order for the bare wafer to act as a pseudo-catalyst, it is necessary to remove the natural oxide film formed on the outermost surface of the bare wafer during step C, so that the Si material is exposed on the outermost surface.

When a bare wafer is used as a pseudo-catalyst, the bare wafer having the Si material exposed on the outermost surface is held at a predetermined position in the boat 217 together with the wafer 200 to be processed, and the boat 217 is moved into the processing chamber 201 in this state. By carrying in, it becomes possible to accommodate a bare wafer, which is a pseudo-catalyst, in the processing chamber 201 . In this case, the boat 217 is alternately loaded with bare wafers, which are pseudo catalysts, and wafers 200, which are to be processed. It is preferable to place the bare wafer directly above the base 200b and the protective film 200e with the front surface facing each other. In this case, in step C, F-containing radicals can be efficiently generated by bringing the F-containing gas into contact with the bare wafer, which is a pseudo-catalyst, and the F-containing radicals thus efficiently generated are transferred to the underlying layer 200b. and protective film 200e. As a result, it becomes possible to appropriately modify the respective surfaces of the underlayer 200b and the protective film 200e.

The processing procedure and processing conditions for selective growth in this case are as described above, except that bare wafers, which are pseudo-catalysts, are set in the boat 217 and that step B is not performed, as in the gas supply sequence shown below. The processing procedure and processing conditions of the aspect can be the same.

O ₂ →Si+F ₂ →(SiCl ₄ →NH ₃ )×n ⇒ SiN

Also in this case, the same effect as the above-described mode can be obtained. Further, in step C, by supplying the F-containing gas in an atmosphere in which the pseudo-catalyst exists, the number of F-containing radicals in the processing chamber 201 is higher than in the case of supplying the F-containing gas in an atmosphere in which the pseudo-catalyst does not exist. It is possible to accelerate the generation and increase the amount of F-containing radicals to be generated. As a result, in step C, modification of the surfaces of the underlayer 200b and the protective film 200e is facilitated, and a SiN film can be properly selectively formed on the surface of the underlayer 200a. In addition, the use of the pseudo-catalyst makes it possible to lower the processing temperature in step C, thereby effectively suppressing the etching of the surface of the underlayer 200a and the etching damage to the surface of the underlayer 200a in step C. Become.

As the pseudo-catalyst, a Si plate (Si plate), a Si chip (Si chip), a Si piece (Si piece), a Si block (Si block), etc. are used instead of the bare wafer. You may do so. When these are used as pseudo-catalysts, it is necessary to remove the natural oxide film formed on the outermost surface of them to create a state in which the Si material is exposed on the outermost surface, as in the case of using bare wafers as pseudo-catalysts. .

Before performing step C, a Si film is previously formed (pre-coated) on the surfaces of the members in the processing chamber 201 (the inner wall of the reaction tube 203, the surface of the boat 217, etc.), and this Si film (pre-coated film) is simulated. It can also be used as a catalyst. A Si film as a precoat film can be formed by a CVD method using, for example, a silane-based gas such as monosilane (SiH ₄ ) gas. The Si film may be an amorphous Si film, a poly (polycrystalline) Si film, or a mixed crystal Si film of amorphous and poly. good too.

The processing conditions for forming the Si film are as follows.
SiH ₄ gas supply flow rate: 10-2000 sccm
N ₂ gas supply flow rate (each gas supply pipe): 0 to 10000 sccm
Gas supply time: 10 to 400 minutes Treatment temperature: 450 to 550°C, preferably 450 to 530°C
Processing pressure: 1 to 900 Pa
are exemplified.

In this case, in step C, F-containing radicals can be efficiently generated by bringing the F-containing gas into contact with the Si film (precoat film) that is a pseudo catalyst, and thus efficiently generated F It becomes possible to efficiently supply the contained radicals to the underlayer 200b and the protective film 200e. As a result, it becomes possible to appropriately modify the respective surfaces of the underlayer 200b and the protective film 200e.

In addition to the Si film, the precoat film includes a SiN film, a silicon carbide film (SiC film), a silicon carbonitride film (SiCN film), a silicon-rich SiN film (SiRN film), a silicon-rich SiC film (SiRC film), A silicon-rich SiCN film (SiRCN film) or the like may be used. That is, a Si-containing film containing C or N other than Si may be used as the precoat film. The SiN film, SiC film, SiCN film, SiRN film, SiRC film, and SiRCN film as the precoat film are, for example, ethylmethylaminosilane (SiH ₃ [N(CH ₃ )(C ₂ H ₅ )]) gas, dimethylaminosilane ( SiH ₃ [N(CH ₃ ) ₂ ]) gas, diisopropylaminosilane (SiH ₃ [N(C ₃ H ₇ ) ₂ ]) gas, di-secondarybutylaminosilane (SiH ₃ [H(C ₄ H ₉ ) ₂ ]) gas It can be formed by a CVD method using an aminosilane-based gas such as. The processing conditions at this time can be the same as the processing conditions for forming the Si film as the precoat film described above. The aminosilane-based gas is a gas containing Si and an amino group, and can be said to be a gas containing at least Si, N, and C as constituent elements.

In these cases as well, in step C, by bringing the F-containing gas into contact with the pseudo-catalyst SiN film, SiC film, SiCN film, SiRN film, SiRC film, and SiRCN film (pre-coated film), the F-containing radicals are effectively removed. , and the F-containing radicals thus efficiently generated can be efficiently supplied to each of the underlayer 200b and the protective film 200e. As a result, it becomes possible to appropriately modify the respective surfaces of the underlayer 200b and the protective film 200e.

The processing procedure and processing conditions for selective growth when these precoated films are used as pseudo-catalysts are as follows: , can be the same as the processing procedure and processing conditions of the above-described aspects. Thus, even when the precoat film is used as a pseudo-catalyst, the same effects as when bareware is used as a pseudo-catalyst can be obtained. The precoat film in this case can also be called a pseudo catalyst film or a pseudo catalyst precoat film.

After the wafer 200 to be processed is housed in the processing chamber 201 and before step C is performed, a Si film is formed on the surface of the wafer 200, that is, on the respective surfaces of the underlayers 200a and 200b and the protective film 200e. and this Si film can be used as a pseudo-catalyst, that is, a pseudo-catalyst film. As the pseudo catalyst film, SiN film, SiC film, SiCN film, SiRN film, SiRC film, SiRCN film, etc. may be used in addition to the Si film. That is, a Si-containing film containing C or N other than Si may be used as the pseudo-catalyst film. Gases and processing conditions used for forming the Si film, SiN film, SiC film, SiCN film, SiRN film, SiRC film, and SiRCN film as pseudo catalyst films are the same as those used for forming the above-described precoat film. It can be the same as the conditions.

In these cases, in step C, by bringing the F-containing gas into contact with the pseudo-catalyst film, the F-containing radicals can be efficiently generated, and the F-containing radicals thus efficiently generated are applied to the underlayer 200b. and the protective film 200e. That is, it is possible to modify the surfaces of the underlayer 200b and the protective film 200e so that they are F-terminated. At this time, the pseudo catalyst film formed on the surface of the underlayer 200a is etched, and adsorption sites are exposed on the surface of the underlayer 200a. At that time, the surface of the underlayer 200a may also be slightly etched, but even in that case, the amount of etching is small, and the adsorption sites on the surface are maintained. Note that the underlayer 200b and the protective film 200e are made of a SiO film and have a strong Si—O bond, so that the surface is not etched, and the surface is properly F-terminated and properly modified. Quality will be done.

The processing procedures and processing conditions for selective growth when using these pseudo catalyst films are the same as those of the above-described modes except that the pseudo catalyst film is formed on the surface of the wafer 200 and Step B is not performed. The processing procedure and processing conditions can be the same. In this way, even when a Si film, a SiN film, a SiC film, a SiCN film, a SiRN film, a SiRC film, a SiRCN film, or the like is used as a pseudo-catalyst, the same effects as when bareware is used as a pseudo-catalyst can be obtained.

Further, for example, as the pseudo-catalyst, not only solid pseudo-catalysts such as bare wafers, Si plates, Si chips, Si pieces, Si blocks, Si-containing pre-coated films, Si-containing pseudo-catalyst films, but also gaseous pseudo-catalysts are used. can also As the gaseous pseudo-catalyst, that is, the pseudo-catalyst gas, a gas that accelerates decomposition of the F-containing gas and generates F-containing radicals from the F-containing gas upon contact with the F-containing gas can be used. Specifically, the pseudo catalyst gas includes at least one of O ₂ gas, N ₂ O gas, N ₂ O gas, NO gas, HF gas, NH ₃ gas, and hydrogen (H ₂ ) gas. one gas can be used. These gases can be supplied at the same time as the F-containing gas is supplied into the processing chamber 201 using, for example, nozzles 249a and 249c.

In this case, in step C, by simultaneously supplying the F-containing gas and the pseudo-catalytic gas into the processing chamber 201, the F-containing gas is supplied in an atmosphere in which the pseudo-catalytic gas exists. At this time, the F-containing gas can be brought into contact with the pseudo-catalyst gas, whereby the F-containing radicals can be efficiently generated. It becomes possible to supply efficiently to each of the films 200e. As a result, it becomes possible to appropriately modify the respective surfaces of the underlayer 200b and the protective film 200e. As long as the F-containing gas and the pseudo-catalyst gas are mixed in the processing chamber 201, the F-containing gas and the pseudo-catalytic gas are alternately or intermittently supplied into the processing chamber 201. can be

The processing procedure and processing conditions for the selective growth in this case are the processing procedure of the above-described mode, except that the F-containing gas and the pseudo catalyst gas are supplied into the processing chamber 201 and that step B is not performed. , can be the same as the processing conditions. Thus, even when supplying the F-containing gas and the pseudo-catalyst gas, the same effects as when bareware is used as the pseudo-catalyst can be obtained. Also, when a gaseous pseudo-catalyst is used, similarly to the case of using a solid pseudo-catalyst, the processing temperature in step C can be lowered, and the etching of the surface of the base 200a and the surface of the base 200a in step C are performed. It becomes possible to effectively suppress the etching damage to the .

A "catalyst" is a substance that does not change itself before and after a chemical reaction, but changes the speed of the reaction. All of the above-mentioned substances exemplified as pseudo-catalysts have a catalytic action of promoting the generation of F-containing radicals, but some of these substances change themselves before and after chemical reactions. For example, NO gas has a catalytic action, but when it reacts with F-containing gas, part of its molecular structure is decomposed, and itself may change before and after the chemical reaction. In this way, even if the substance itself changes before and after the chemical reaction, the substance that changes the rate of the reaction is referred to as a "pseudo-catalyst" in this specification.

Further, for example, in step C, generation of F-containing radicals from the F-containing gas may be promoted by activation (excitation) of the F-containing gas by plasma, heating, light irradiation, or the like. Also in these cases, the same effects as those of the above embodiments can be obtained. Further, in step C, by activating the F-containing gas by plasma, heating, light irradiation, etc., the generation of F-containing radicals in the processing chamber 201 is promoted more than when the F-containing gas is not activated by these. , it becomes possible to increase the amount of F-containing radicals to be generated. As a result, in step C, modification of the surfaces of the underlayer 200b and the protective film 200e is facilitated, and a SiN film can be properly selectively formed on the surface of the underlayer 200a. Also, the processing temperature in step C can be lowered. When plasma is used, the F-containing gas is activated by plasma in a remote plasma unit provided outside the processing chamber 201 in order to suppress plasma damage to the wafer 200 and members in the processing chamber 201. It is preferable to adopt a method of supplying the plasma into the processing chamber 201 afterward, that is, a remote plasma method.

Further, in the above-described mode, steps A, B, C, and D are sequentially performed on the wafer 200 having the exposed surface of the underlayer 200a containing the SiN film, the underlayer 200b containing the SiO film, and the underlayer 200c containing single-crystal Si. Although examples have been provided, the disclosure is not limited to such aspects. For example, the surface of the wafer 200 includes a SiCN film, a silicon boronitride film (SiBN film), a silicon borocarbonitride film (SiBCN film), and a silicon borocarbide film (SiBC film) instead of the underlayer 200a including the SiN film. The substrate may be exposed. Further, for example, instead of the underlying layer 200b containing the SiO film, an underlying layer containing a silicon oxycarbide film (SiOC film), a silicon oxynitride film (SiON film), or a silicon oxycarbonitride film (SiOCN film) may be exposed. . Further, for example, an epitaxial silicon film (Epi-Si film), a polysilicon film (poly-Si film (polycrystalline Si film)), an amorphous silicon film (a-Si film (non The underlayer containing the crystalline Si film)) may be exposed. Further, for example, in addition to the underlayer 200a containing the SiN film, the underlayer 200b containing the SiO film, and the underlayer 200c containing the monocrystalline Si, a tungsten film (W film), a tungsten nitride film (WN film), and a titanium nitride film (TiN film) A base containing a conductive metal-based thin film such as may be exposed. Further, instead of the underlayer 200a including the SiN film, the underlayer including the metal-based thin film described above may be exposed. Also in these cases, the same effects as those of the above embodiments can be obtained. That is, it is possible to selectively form a film on the surface of the underlayer 200a and the surface of the metal-based thin film described above while avoiding film formation on the underlayers 200b and 200c.

Further, in the above aspect, an example of using monoaminosilane gas as the aminosilane-based gas in step B has been described, but the present disclosure is not limited to such an aspect. For example, in step B, instead of monoaminosilane gas, diaminosilane gas or triaminosilane gas may be used as the aminosilane-based gas. Also in these cases, the same effects as those of the above embodiments can be obtained. However, in step B, the adsorption density of Si on the surfaces of the underlayer 200b and the protective film 200e increases as the number of amino groups contained in one molecule decreases as the aminosilane-based gas is used. , the density of SiF terminations formed on the respective surfaces of the underlayer 200b and the protective film 200e increases. As a result, in step D, it is possible to enhance the effect of inhibiting film formation on the surfaces of the base 200b and the protective film 200e. In this respect, it is particularly preferable to use monoaminosilane, which contains one amino group per molecule, as the aminosilane-based gas.

Further, in the above-described aspect, an example in which a cycle of performing steps D1 and D2 non-simultaneously is performed a predetermined number of times in step D has been described, but the present disclosure is not limited to such an aspect. For example, in step D, before starting a cycle in which steps D1 and D2 are performed non-simultaneously, wafers 200 in processing chamber 201, that is, substrates 200a and 200b and protective film 200e among substrates 200a and 200b and protective film 200e are A step of supplying NH ₃ gas for a predetermined time (NH ₃ preflow) may be performed on the wafer 200 after selectively modifying the surface. Even in this case, the F terminations existing on the respective surfaces of the underlayer 200b and the protective film 200e are stably maintained without being extinguished. Moreover, the adsorption sites on the surface of the underlayer 200a can be optimized, and the quality of the SiN film formed on the underlayer 200a can be improved.

Further, in the above aspect, an example of using SiCl ₄ gas as the source gas and NH ₃ gas as the reaction gas in step D has been described, but the present disclosure is not limited to such an aspect. For example, in step D, in addition to SiCl ₄ gas, the above-described chlorosilane-based gas or metal halide gas such as titanium tetrachloride (TiCl ₄ ) gas may be used. Further, for example, as the reaction gas, in addition to N-containing gas such as _NH3 gas, O-containing gas such as oxygen ( _O2 ) gas _, N and N such as triethylamine ₍ ( _C2H5 )3N, abbreviation: TEA) gas C-containing gas, C-containing gas such as propylene (C ₃ H ₆ ) gas, and boron (B)-containing gas such as trichloroborane (BCl ₃ ) gas may be used. Then, by the gas supply sequence described below, SiON film, SiCN film, SiOCN film, SiOC film, SiBN film, SiBCN film, A film such as a TiN film or a titanium oxynitride film (TiON film) may be formed. Since the F termination formed on the surfaces of the underlayers 200b and 200c is very stable, in these cases, that is, when a gas containing an OH group such as water vapor (H ₂ O gas) is not used as the film forming gas, has the same effect as the above-described mode.

_O2 → _SiH3R →F2→( _SiCl4 → _NH3 → _O2 )× _n →SiON
_O2 → _SiH3R →F2→ _{( HCDS} → _C3H6 → _NH3 )×n→SiCN
_O2 → _SiH3R →F2→(HCDS→ _C3H6 → _NH3 → _O2 )× _n → _SiOCN
O2 → _SiH3R →F2→(HCDS→TEA→ _O2 )× _n ⇒ SiOC(N)
_O2 → _SiH3R →F2→(DCS→ _BCl3 → _NH3 )×n→ _SiBN
O2 → _SiH3R →F2→ ₍ DCS→ _C3H6 → _BCl3 → _NH3 )×n→ _SiBCN
O2 → _SiH3R →F2→ _{( TiCl4} → _NH3 )×n ⇒ TiN
_O2 → _SiH3R →F2→( _TiCl4 → _NH3 → _O2 )×n→ _TiON

Further, in the above aspect, an example of performing DHF cleaning on the wafer 200 before performing selective growth has been described, but the present disclosure is not limited to such an aspect. For example, after forming the underlayer 200a, the natural oxide film 200d is not formed on the surfaces of the underlayers 200a and 200c unlike the above-described selective growth without exposing the underlayers 200a and 200c to the atmosphere. In some cases, DHF cleaning may be omitted.

Recipes used for each process are preferably prepared individually according to the contents of the process and stored in the storage device 121c via an electric communication line or the external storage device 123. FIG. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe from among the plurality of recipes stored in the storage device 121c according to the content of the process. As a result, a single substrate processing apparatus can form films having various film types, composition ratios, film qualities, and film thicknesses with good reproducibility. In addition, the burden on the operator can be reduced, and each process can be started quickly while avoiding operational errors.

The above-described recipe is not limited to the case of newly creating the recipe, but may be prepared by modifying an existing recipe that has already been installed in the substrate processing apparatus, for example. When changing the recipe, the changed recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium recording the recipe. Alternatively, an existing recipe already installed in the substrate processing apparatus may be directly changed by operating the input/output device 122 provided in the existing substrate processing apparatus.

In the above embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes a plurality of substrates at once has been described. The present disclosure is not limited to the embodiments described above, and can be suitably applied, for example, to the case of forming a film using a single substrate processing apparatus that processes one or several substrates at a time. Further, in the above embodiments, 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 embodiments, and can be suitably applied to the case of forming a film using a substrate processing apparatus having a cold wall type processing furnace.

Even when these substrate processing apparatuses are used, each process can be performed under the same processing procedure and processing conditions as in the above-described mode, and the same effect as in the above-described mode can be obtained.

The above aspects can be used in combination as appropriate. The processing procedure and processing conditions at this time can be, for example, the same as the processing procedures and processing conditions of the above-described mode.

A plurality of wafers having surfaces exposed to a SiN film (first underlayer), a SiO film (second underlayer), and a single-crystal Si (third underlayer) were prepared, and the surface of each wafer was dipped in a DHF aqueous solution. The SiN film and the natural oxide film formed on the surface of the single-crystal Si in each wafer were removed by cleaning using the cleaning agent. After that, using the substrate processing apparatus shown in FIG. 1, a process for forming a SiN film was performed on each wafer, and two evaluation samples (Samples 1 and 2) were produced.

When producing Sample 1 (Example), Steps A to D in the above-described mode were performed respectively. The processing conditions in steps A to D were predetermined conditions within the range of processing conditions described in the above embodiments.

When producing Sample 2 (comparative example), Step A in the above-described embodiment was not performed, and Steps BD were performed. The processing conditions in steps BD were the same as the processing conditions in steps BD when sample 1 was produced.

Observation of both the SEM and TEM images of the cross sections of Samples 1 and 2 confirmed that the surface of the third underlayer of Sample 1 subjected to Step A was not damaged by etching. On the other hand, in sample 2 in which step A was not performed, it was confirmed that the surface of the third base underwent etching damage. In both samples 1 and 2, it was confirmed that the SiN film could be selectively formed only on the surface of the first underlayer.

<Preferred Embodiment of the Present Disclosure>
Preferred embodiments are described below.

(Appendix 1)
According to one aspect of the present disclosure,
(a) supplying a processing gas to a substrate having an exposed surface of a first underlayer containing no oxygen, a second underlayer containing oxygen, and a third underlayer containing no oxygen and nitrogen; a step of (selectively) forming a protective film on the surface of the third underlayer;
(b) The surface of the second underlayer is (selectively) terminated with fluorine by supplying a fluorine-containing gas to the substrate after the protective film is formed on the surface of the third underlayer. a questioning process;
(c) selectively forming a film on the surface of the first underlayer by supplying a film-forming gas to the substrate after modifying the surface of the second underlayer;
A method of manufacturing a semiconductor device or a method of processing a substrate is provided.

(Appendix 2)
The method of Appendix 1,
The protective film contains oxygen.

(Appendix 3)
The method according to Appendix 2,
In (a), an oxygen-containing gas is supplied as the processing gas, and the surface of the third underlayer is oxidized to form the protective film.

(Appendix 4)
The method according to Appendix 3,
In (a), the surface of the third underlayer is oxidized by dry oxidation.

(Appendix 5)
The method according to Appendix 3 or 4,
In (a), the surface of the third underlayer is oxidized under a pressure lower than atmospheric pressure.

(Appendix 6)
The method according to any one of Appendices 3 to 5,
In (a), the surface of the third underlayer is oxidized under conditions in which the surface of the first underlayer is not oxidized. That is, in (a), the protective film is formed on the surface of the third underlayer under conditions in which the protective film is not formed on the surface of the first underlayer.

(Appendix 7)
The method according to any one of Appendices 2 to 6,
In (b), the surface of the protective film is also modified so as to be terminated with fluorine.

(Appendix 8)
The method according to any one of Appendices 1 to 7,
In (b), the surface of the second underlayer is modified so as to be fluorine-terminated without being etched. In addition, in (b), the surface of the protective film is also modified so as to be fluorine-terminated without being etched.

(Appendix 9)
The method according to any one of Appendices 1 to 8,
In (b), the fluorine-containing gas is supplied to the substrate in an atmosphere containing silicon.

(Appendix 10)
The method according to any one of Appendices 1 to 9,
In (b)
(b1) supplying an aminosilane-based gas to the substrate;
(b2) supplying the fluorine-containing gas to the substrate;
are sequentially performed, the surface of the second underlayer is modified so as to be fluorine-terminated.

(Appendix 11)
The method according to Appendix 10,
In (b1), silicon contained in the aminosilane-based gas is adsorbed on the surface of the second underlayer,
In (b2), the silicon adsorbed on the surface of the second underlayer is reacted with the fluorine-containing gas to terminate the surface of the second underlayer with fluorine.

(Appendix 12)
The method according to Appendix 11,
In (b1), silicon contained in the aminosilane-based gas is adsorbed on the surface of the protective film,
In (b2), the silicon adsorbed on the surface of the protective film is reacted with the fluorine-containing gas to terminate the surface of the second underlayer with fluorine.

(Appendix 13)
The method according to any one of Appendices 1 to 12,
The method further includes (d) removing a natural oxide film formed on the surface of the substrate before performing (a).

(Appendix 14)
13. The method according to Appendix 13,
In (d), the material of the first underlayer is exposed.

(Appendix 15)
14. The method of Appendix 14,
In (d), the material of the third underlayer is exposed.

(Appendix 16)
The method according to any one of Appendices 1 to 15,
The first underlayer comprises a nitride layer, the second underlayer comprises an oxide layer, and the third underlayer comprises a semiconductor material.

(Appendix 17)
The method according to any one of Appendices 1 to 16,
The first underlayer contains silicon and nitrogen, the second underlayer contains silicon and oxygen, and the third underlayer contains silicon.

(Appendix 18)
The method according to any one of Appendices 1 to 17, preferably
The first underlayer includes a silicon nitride film, the second underlayer includes a silicon oxide film, and the third underlayer includes monocrystalline silicon, an epitaxial silicon film, a polycrystalline silicon film, or an amorphous silicon film.

(Appendix 19)
According to another aspect of the present disclosure,
a processing chamber in which the substrate is processed;
a processing gas supply system that supplies a processing gas to the substrate in the processing chamber;
a fluorine-containing gas supply system for supplying a fluorine-containing gas to the substrate in the processing chamber;
a film forming gas supply system for supplying a film forming gas to the substrate in the processing chamber;
In the processing chamber, the processing gas supply system, the fluorine-containing gas supply system, and the film formation gas supply system are configured to be able to be controlled so as to perform each process (each process) of Supplementary Note 1. a control unit that
A substrate processing apparatus is provided.

(Appendix 20)
According to yet another aspect of the present disclosure,
A program for causing the substrate processing apparatus to execute each procedure (each process) of Supplementary Note 1 by a computer in the processing chamber of the substrate processing apparatus, or a computer-readable recording medium recording the program is provided.

200 wafer (substrate)
200a First base 200b Second base 200c Third base

Claims (21)

(a) providing a substrate having on its surface a first oxygen-free underlayer, a second oxygen-containing underlayer, and a third oxygen- and nitrogen-free underlayer having a protective film formed thereon;
(b) supplying a fluorine-containing gas to the substrate in a state where the protective film is formed on the surface of the third underlayer, thereby modifying the surface of the second underlayer so as to terminate the surface with fluorine; process and
(c) forming a film on the surface of the first underlayer by supplying a film-forming gas to the substrate while the surface of the second underlayer is modified;
A substrate processing method comprising: 2. The substrate processing method according to claim 1, wherein said protective film contains oxygen. 2. The substrate processing method according to claim 1, wherein said protective film contains silicon and oxygen. 4. The substrate processing method according to claim 2, wherein the protective film is formed by oxidizing the surface of the third base. 4. The substrate processing method according to claim 2, wherein the protective film is formed by oxidizing the surface of the third base with an oxidizing agent. 6. The substrate processing method according to claim 2, wherein the protective film is formed by oxidizing the surface of the third underlayer under conditions that do not oxidize the surface of the first underlayer. 7. The substrate processing method according to any one of claims 2 to 6, wherein in (b), the surface of the protective film is also modified so as to be fluorine-terminated. 8. The substrate processing method according to any one of claims 1 to 7, wherein in (b), the surface of the second underlayer is modified so as to be fluorine-terminated without being etched. 9. The substrate processing method according to claim 1, wherein in (b), the fluorine-containing gas is supplied to the substrate in an atmosphere containing silicon. (b) is
(b1) adsorbing silicon to the surface of the second underlayer;
(b2) reacting the silicon adsorbed on the surface of the second underlayer with the fluorine-containing gas to terminate the surface of the second underlayer with fluorine;
The substrate processing method according to any one of claims 1 to 9, having In (b1), silicon is also adsorbed on the surface of the protective film,
11. The substrate processing method according to claim 10, wherein in (b2), the surface of the protective film is also fluorine-terminated by reacting the silicon adsorbed on the surface of the protective film with the fluorine-containing gas. (b) is
(b1) supplying an aminosilane-based gas to the substrate;
(b2) supplying the fluorine-containing gas to the substrate;
The substrate processing method according to any one of claims 1 to 11. 13. The substrate processing method according to claim 1, further comprising (d) removing a natural oxide film formed on the surface of the substrate before performing (a). 14. The substrate processing method according to claim 13, wherein in (d), the material of the first underlayer is exposed. 15. The substrate processing method according to claim 13, wherein in (d), the material of the third underlayer is exposed. 16. The substrate processing method of claim 1, wherein the first underlayer comprises a nitride film, the second underlayer comprises an oxide film, and the third underlayer comprises a semiconductor material. 17. The substrate processing method according to claim 1, wherein the first underlayer contains silicon and nitrogen, the second underlayer contains silicon and oxygen, and the third underlayer contains silicon. The first underlayer includes a silicon nitride film, the second underlayer includes a silicon oxide film, and the third underlayer includes at least one of monocrystalline silicon, an epitaxial silicon film, a polycrystalline silicon film, and an amorphous silicon film. The substrate processing method according to any one of claims 1 to 17. (a) providing a substrate having on its surface a first oxygen-free underlayer, a second oxygen-containing underlayer, and a third oxygen- and nitrogen-free underlayer having a protective film formed thereon;
(b) supplying a fluorine-containing gas to the substrate in a state where the protective film is formed on the surface of the third underlayer, thereby modifying the surface of the second underlayer so as to terminate the surface with fluorine; process and
(c) forming a film on the surface of the first underlayer by supplying a film-forming gas to the substrate while the surface of the second underlayer is modified;
A method of manufacturing a semiconductor device having a processing chamber in which the substrate is processed;
a fluorine-containing gas supply system for supplying a fluorine-containing gas to the substrate in the processing chamber;
a film forming gas supply system for supplying a film forming gas to the substrate in the processing chamber;
(a) providing a substrate having on its surface a first oxygen-free underlayer, a second oxygen-containing underlayer, and a third oxygen- and nitrogen-free underlayer having a protective film formed thereon; (b) modifying the surface of the second underlayer so that the surface of the second underlayer is fluorine-terminated by supplying the fluorine-containing gas to the substrate in a state where the protective film is formed on the surface of the third underlayer; and (c) a process of forming a film on the surface of the first underlayer by supplying the film-forming gas to the substrate in a state where the surface of the second underlayer is modified. , a control unit configured to be able to perform
A substrate processing apparatus having (a) providing a substrate having on its surface a first oxygen-free underlayer, a second oxygen-containing underlayer, and a third oxygen- and nitrogen-free underlayer having a protective film formed thereon;
(b) supplying a fluorine-containing gas to the substrate in a state where the protective film is formed on the surface of the third underlayer, thereby modifying the surface of the second underlayer so as to terminate the surface with fluorine; a procedure;
(c) forming a film on the surface of the first underlayer by supplying a film-forming gas to the substrate while the surface of the second underlayer is modified;
A program that causes a substrate processing apparatus to execute by a computer.

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