阅读说明：本技术 半导体装置的制造方法、基板处理装置和程序 (Method for manufacturing semiconductor device, substrate processing apparatus, and program ) 是由 芦原洋司 出贝求 早稻田崇之 于 2018-07-17 设计创作，主要内容包括：在抑制不形成薄膜的膜的损伤的同时在基板上选择性形成薄膜。依次进行以下工序：向在表面至少露出第一膜和与上述第一膜不同的第二膜的基板供给第一无机系材料,从上述基板的表面除去自然氧化膜的工序；向上述基板供给氧化剂,使上述第一膜氧化,在表面再形成氧化膜的工序；向上述基板供给第二无机系材料,对上述第一膜的表面进行改性的工序；和向上述基板供给堆积气体,在上述第二膜的表面选择性生长薄膜的工序。(A thin film is selectively formed on a substrate while suppressing damage to a film on which the thin film is not formed. The following steps are sequentially carried out: a step of supplying a first inorganic material to a substrate having a surface on which at least a first film and a second film different from the first film are exposed, and removing a natural oxide film from the surface of the substrate; supplying an oxidizing agent to the substrate to oxidize the first film and form an oxide film on the surface of the substrate; a step of modifying the surface of the first film by supplying a second inorganic material to the substrate; and supplying a deposition gas to the substrate to selectively grow a thin film on the surface of the second film.)

1. A method for manufacturing a semiconductor device, comprising the steps of:

a step of supplying a first inorganic material to a substrate having a surface on which at least a first film and a second film different from the first film are exposed, and removing a natural oxide film from the surface of the substrate,

a step of supplying an oxidizing agent to the substrate to oxidize the first film and form an oxide film on the surface,

a step of modifying the surface of the first film by supplying a second inorganic material to the substrate, and

and supplying a deposition gas to the substrate to selectively grow a thin film on the surface of the second film.

2. The method for manufacturing a semiconductor device according to claim 1,

the first inorganic material is a first halogen material containing a halogen element.

3. The method for manufacturing a semiconductor device according to claim 2,

the first halogen-based material is hydrogen fluoride.

4. The method for manufacturing a semiconductor device according to claim 1,

the oxidizing agent is composed of at least 1 of ammonia, hydrogen peroxide water, hydrogen peroxide gas, a mixed gas of oxygen active species and hydrogen active species, and oxygen.

5. The method for manufacturing a semiconductor device according to claim 1,

the oxidizing agent is a mixed solution of ammonia and hydrogen peroxide water.

6. The method for manufacturing a semiconductor device according to claim 1,

the second inorganic material is a second halogen material.

7. The method for manufacturing a semiconductor device according to claim 6,

the second halogen-based material is a fluorine-containing gas.

8. The method for manufacturing a semiconductor device according to any one of claims 1 to 7,

the stacking gas contains a raw material gas and a reaction gas that reacts with the raw material gas,

in the step of selectively growing a thin film on the surface of the second film, the source gas and the reaction gas are alternately supplied without being mixed with each other.

9. The method for manufacturing a semiconductor device according to claim 8, wherein,

the raw material gas is a third halogen material.

10. The method for manufacturing a semiconductor device according to claim 8, wherein,

the raw material gas is a chlorine-containing gas.

11. The method for manufacturing a semiconductor device according to claim 1,

the first film is a silicon film.

12. The method for manufacturing a semiconductor device according to claim 1,

the second film is a silicon nitride film.

13. The method for manufacturing a semiconductor device according to claim 1,

the thin film is a nitride film.

14. The method for manufacturing a semiconductor device according to claim 1,

after the step of selectively growing the thin film on the surface of the second film, a step of supplying an etching gas to the substrate to etch a thin film formed on the surface of the substrate other than the surface of the second film is performed.

15. The method for manufacturing a semiconductor device according to claim 14, wherein the following steps are sequentially repeated a plurality of times:

the method includes a step of modifying the surface of the first film, a step of selectively growing a thin film on the surface of the second film, and a step of etching a thin film formed on the surface of the substrate other than the surface of the second film.

16. A substrate processing apparatus includes:

a first processing chamber for accommodating a substrate,

a first gas supply system for supplying a first inorganic material to the first processing chamber,

a second gas supply system for supplying an oxidizing agent to the first processing chamber,

a second processing chamber for accommodating the substrate,

a third gas supply system for supplying a second inorganic material to the second processing chamber,

a third processing chamber for accommodating the substrate,

a fourth gas supply system for supplying a deposition gas to the third process chamber,

a transfer system for transferring the substrate into and out of the first, second, and third processing chambers, and

a control unit configured to control the first gas supply system, the second gas supply system, the third gas supply system, the fourth gas supply system, and the conveyance system so as to perform: a process of carrying into the first processing chamber a substrate having a surface on which at least a first film and a second film different from the first film are exposed; a process of supplying the first inorganic material to the first process chamber to remove a natural oxide film from the surface of the substrate; supplying the oxidizing agent to the first processing chamber to oxidize the first film and reform an oxide film on the surface of the first film; a process of carrying out the substrate from the first process chamber; a process of carrying the substrate into the second process chamber; a process of supplying the second inorganic material to the second process chamber to modify the surface of the first film; a process of carrying out the substrate from the second process chamber; a process of carrying the substrate into the third process chamber; and a process of supplying the deposition gas to the third process chamber to selectively grow a thin film on the surface of the second film.

17. A substrate processing apparatus includes:

a processing chamber for accommodating the substrate therein,

a first gas supply system for supplying a first inorganic material to the processing chamber,

a second gas supply system for supplying an oxidizing agent to the processing chamber,

a third gas supply system for supplying a second inorganic material to the processing chamber,

a fourth gas supply system for supplying a deposition gas to the processing chamber, an

A control unit configured to control the first gas supply system, the second gas supply system, the third gas supply system, and the fourth gas supply system so as to perform: a process of supplying the first inorganic material to the process chamber containing a substrate having at least a first film and a second film different from the first film exposed on a surface thereof, and removing a natural oxide film from the surface of the substrate; a process of supplying the oxidizing agent to the process chamber to oxidize the first film to reform an oxide film on the surface; a process of supplying the second inorganic material to the process chamber to modify the surface of the first film; and a process of supplying the deposition gas to the process chamber to selectively grow a thin film on the surface of the second film.

18. A program for causing a substrate processing apparatus to execute, by a computer, the processes of:

a step of carrying a substrate having at least a first film and a second film different from the first film exposed on a surface thereof into a first processing chamber of the substrate processing apparatus,

a step of supplying a first inorganic material to the substrate and removing a natural oxide film from the surface of the substrate,

a step of supplying an oxidizing agent to the substrate to oxidize the first film and reform an oxide film on the surface,

a process of carrying out the substrate from the first processing chamber,

a step of carrying the substrate into a second processing chamber of the substrate processing apparatus,

a step of supplying a second inorganic material to the substrate to modify the surface of the first film,

a process of carrying out the substrate from the second processing chamber,

a process of carrying the substrate into a third processing chamber of the substrate processing apparatus, and

and a step of supplying a deposition gas to the substrate to selectively grow a thin film on the surface of the second film.

19. A program for causing a substrate processing apparatus to execute, by a computer, the processes of:

a step of supplying a first inorganic material to a substrate, which is accommodated in a processing chamber of the substrate processing apparatus and has a surface on which at least a first film and a second film different from the first film are exposed, and removing a natural oxide film from the surface of the substrate,

a step of supplying an oxidizing agent to the substrate to oxidize the first film and reform an oxide film on the surface,

a process of supplying a second inorganic material to the substrate, modifying the surface of the first film, and

and a step of supplying a deposition gas to the substrate to selectively grow a thin film on the surface of the second film.

Technical Field

The invention relates to a method for manufacturing a semiconductor device, a substrate processing apparatus, and a program.

Background

With the miniaturization of Large Scale Integrated circuits (LSIs), the miniaturization of pattern formation techniques has also progressed. As a patterning technique, for example, a hard mask is used, but with the miniaturization of the patterning technique, it becomes difficult to apply a method of dividing an etched region and a non-etched region by exposing a resist. Therefore, epitaxial films such as silicon (Si) and silicon germanium (SiGe) are selectively grown and formed on a substrate such as a silicon (Si) wafer (see, for example, patent documents 1 and 2).

In addition, with the miniaturization of LSIs, the complexity of methods for controlling the functions of transistor elements has increased. A Transistor of a type in which a voltage is applied to an electrode called a gate and a current of a conductive portion called a channel is controlled by an electric Field is called a Field Effect Transistor (hereinafter, referred to as FET). In forming Fin in the FET, a method of processing a conductive portion such as a silicon nitride film (SiN film) is widely used.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-100746

Patent document 2: japanese patent laid-open publication No. 2015-122481

Disclosure of Invention

Problems to be solved by the invention

Here, high processing accuracy is required in forming Fin, and from the viewpoint of widely securing a path through which a current flows, it is desirable to process as vertically as possible by dry etching. However, when the SiN film is used as a hard mask, a small amount of etching is performed not only on the upper surface but also on the side surface of the SiN film, and thus the SiN film cannot be used as a mask, and it is difficult to obtain an ideal vertical Si processing shape. Further, the aspect ratio, which is the ratio of the height of Fin to the width thereof, tends to increase, and the SiN film is insufficient and difficult to process to a predetermined depth.

The purpose of the present invention is to selectively form a thin film on a substrate while suppressing damage to the film on which the thin film is not formed.

Means for solving the problems

According to an aspect of the present invention, there is provided a technique of sequentially performing the following steps:

a step of supplying a first inorganic material to a substrate having a surface on which at least a first film and a second film different from the first film are exposed, and removing a natural oxide film from the surface of the substrate,

a step of supplying an oxidizing agent to the substrate to oxidize the first film and form an oxide film on the surface,

a step of modifying the surface of the first film by supplying a second inorganic material to the substrate, and

and supplying a deposition gas to the substrate to selectively grow a thin film on the surface of the second film.

Effects of the invention

According to the present invention, a thin film can be selectively formed on a substrate while suppressing damage to a film on which the thin film is not formed.

Drawings

Fig. 1 is a top cross-sectional view for explaining a substrate processing apparatus 10 according to an embodiment of the present invention.

Fig. 2 is a diagram for explaining the structure of the processing furnace 202a of the substrate processing apparatus 10 according to the embodiment of the present invention.

FIG. 3 is a vertical sectional view for explaining the structure of the treatment furnace 202a shown in FIG. 2.

Fig. 4 is a vertical sectional view for explaining the structure of the processing furnaces 202b,202d of the substrate processing apparatus 10 according to the embodiment of the present invention.

Fig. 5 is a cross-sectional view of the top surface of the processing furnaces 202b,202d shown in fig. 4.

Fig. 6 is a diagram for explaining the structure of the processing furnace 202c of the substrate processing apparatus 10 according to the embodiment of the present invention.

Fig. 7 is a sectional view of the upper surface of the treatment furnace 202c shown in fig. 6.

Fig. 8 is a block diagram showing a control configuration of the substrate processing apparatus 10 according to the embodiment of the present invention.

Fig. 9 is a flowchart showing a control flow of the controller of the substrate processing apparatus 10 according to the embodiment of the present invention.

In FIG. 10, (A) shows the Si layer and SiO layer formed after the natural oxide film removing step₂The pattern diagram of the wafer surface states of the layer and the SiN layer, (B) is a pattern diagram showing the wafer surface state after the oxide film re-forming step, and (C) is a pattern diagram showing the state of the ClF just after the ClF supply₃A schematic diagram of the state of the wafer surface after the gas is generated.

In FIG. 11, (A) shows just after SiCl was supplied₄After the gas is formed, a Si layer and SiO layer are formed₂The pattern of the surface state of the wafer of the layer and SiN layer (B) is a diagram showing that NH is just supplied₃The pattern diagram of the wafer surface state after the gas treatment, and (C) the pattern diagram showing the wafer surface state immediately after the film formation treatment.

In FIG. 12, (A) shows the Si layer and SiO layer before the etching treatment₂The pattern of the surface states of the wafer of the layer and the SiN layer is shown in (B) which shows that ClF is just supplied₃A schematic view showing the state of the wafer surface after the gas supply, wherein (C) is a schematic view showing the state immediately after the supply of N₂The schematic view of the state of the wafer surface after the gas treatment, and (D) are views showing the wafer surface after the substrate treatment process according to one embodiment of the present invention.

In FIG. 13, (A) shows that a Si layer and SiO layer are formed when a SiN film is selectively grown in a substrate processing apparatus and a substrate processing step according to the present invention₂The cross-sectional view of the wafer of the layer and the SiN layer, (B) is an enlarged view showing the surface state of the SiN layer of (a), and (C) is an enlarged view showing the surface state of the Si layer of (a).

In FIG. 14, (A) is a value obtained when APM cleaning is not performed in the substrate treatment process of the present inventionWith a Si layer, SiO₂The cross-sectional view of the wafer of the layer and the SiN layer, (B) is an enlarged view showing the surface state of the SiN layer of (a), and (C) is an enlarged view showing the surface state of the Si layer of (a). (D) In the substrate processing step of the present invention, when DHF cleaning is not performed, a Si layer and SiO layer are formed₂The cross-sectional views of the wafer of the layer and the SiN layer are shown in (E) an enlarged view showing the surface state of the SiN layer in (D) and (F) an enlarged view showing the surface state of the Si layer in (D).

In fig. 15, (a) is a graph showing the relationship between DHF cleaning and APM cleaning and the film thickness of the selectively formed SiN film when the base film is a SiN layer, and (B) is a graph showing the relationship between DHF cleaning and APM cleaning and the film thickness of the selectively formed SiN film when the base film is a Si layer.

Fig. 16 is a vertical sectional view for explaining the structure of the processing furnace 202e of the substrate processing apparatus 300 according to another embodiment of the present invention.

Fig. 17 is a sectional view of the upper surface of the treatment furnace 202e shown in fig. 16.

Detailed Description

Next, preferred embodiments of the present invention will be explained. Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

(1) Structure of substrate processing apparatus

Fig. 1 is a top cross-sectional view of a substrate processing apparatus (hereinafter simply referred to as substrate processing apparatus 10) for carrying out a method of manufacturing a semiconductor device. The conveyance device of the cluster substrate processing apparatus 10 according to the present embodiment is divided into a vacuum side and an atmosphere side. In the substrate processing apparatus 10, a FOUP (Front Opening Unified Pod, hereinafter referred to as a wafer container) 100 is used as a carrier for transporting a wafer 200 as a substrate.

(construction of vacuum side)

As shown in fig. 1, the substrate processing apparatus 10 includes a first transfer chamber 103 capable of withstanding a pressure (negative pressure) lower than atmospheric pressure such as a vacuum state. The casing 101 of the first transfer chamber 103 is, for example, pentagonal in plan view, and is formed in a box shape with closed upper and lower ends.

In the first transfer chamber 103, a first substrate transfer unit 112 for transferring the wafer 200 is provided. The first substrate transfer unit 112 is used as a transfer system for transferring the wafer 200 into and out of the processing furnaces 202a to 202d, which will be described later.

The front side wall of the five side walls of the enclosure 101 is connected to the preliminary chambers (closed loading chambers) 122 and 123 via gate valves 126 and 127, respectively. The preparation chambers 122 and 123 are configured to have a function of loading the wafer 200 and a function of unloading the wafer 200, and are configured to be capable of receiving a negative pressure.

Four side walls located on the rear side (back side) of the five side walls of the enclosure 101 of the first transfer chamber 103 are respectively adjacent to and connected to a processing furnace 202a as a first process unit, a processing furnace 202b as a second process unit, a processing furnace 202c as a third process unit, and a processing furnace 202d as a fourth process unit, which accommodate substrates and perform desired processing on the accommodated substrates, via gate valves 70a,70b,70c, and 70 d.

(constitution of atmosphere side)

The front sides of the preliminary chambers 122 and 123 are connected to a second transfer chamber 121 capable of transferring the wafer 200 in an atmospheric pressure state via gate valves 128 and 129. The second transfer chamber 121 is provided with a second substrate transfer unit 124 for transferring the wafer 200.

A notch aligning device 106 is provided on the left side of the second transfer chamber 121. It should be noted that the notch alignment device 106 may also be a directional plane alignment device. A cleaning unit for supplying cleaning air is provided above the second conveyance chamber 121.

A substrate loading/unloading port 134 for loading/unloading the wafer 200 into/from the second transfer chamber 121 and a wafer container opener 108 are provided in front of the enclosure 125 of the second transfer chamber 121. A load port (IO stage) 105 is provided on the opposite side of the substrate carry-in/out port 134 from the wafer container opener 108, that is, on the outer side of the enclosure 125. The wafer container opener 108 has a shutter capable of opening and closing the cap 100a of the wafer container 100 and closing the substrate loading/unloading port 134. The wafer 200 can be carried into and out of the wafer container 100 by opening and closing the cap 100a of the wafer container 100 placed in the loading port 105. The wafer container 100 can be supplied to and discharged from the load port 105 by an in-process transport apparatus (OHT or the like), not shown.

(constitution of the treating furnace 202 a)

Fig. 2 is a schematic configuration diagram of a processing furnace 202a as a first process unit included in the substrate processing apparatus 10, and fig. 3 is a longitudinal sectional view of the processing furnace 202 a.

In this embodiment, the processing furnace 202a is used as a cleaning unit (substrate cleaning apparatus) for removing a natural oxide film and forming an oxide film on the surface of the Si layer again.

The processing furnace 202a is a single-wafer processing furnace that processes 1 or more wafers at a time. The DHF supply unit 14, the SC1 liquid supply unit 17, the DIW supply unit 18, and the cleaning liquid supply unit 22 are connected to the processing furnace 202 a.

The DHF supply unit 14 supplies a chemical solution such as a first halogen material (halide) containing a halogen element, i.e., a first inorganic material, diluted hydrofluoric acid (DHF), into the processing furnace 202 a.

The SC1 liquid supply unit 17 supplies ammonia (NH) as an oxidizing agent₃) Water and hydrogen peroxide (H)₂O₂) A chemical liquid such as a water mixed solution (hereinafter, referred to as SC1 liquid) is supplied into the processing furnace 202 a.

The DIW supply unit 20 supplies a rinse liquid such as deionized water (DIW) into the processing furnace 202 a.

The cleaning liquid supply unit 22 supplies a cleaning liquid as a pipe cleaning liquid into the processing furnace 202 a. As the cleaning liquid, for example, an oxidizing liquid obtained by mixing at least one of hydrogen peroxide water, ozone water, hypochlorous acid, nitric acid, chloramine, and dimethyl sulfoxide, an organic solvent containing at least one of methanol, ethanol, isopropyl alcohol, n-propanol, ethylene glycol, and 2-methyl-2-propanol, or the like can be used.

The DHF supply unit 14 is connected to the treatment furnace 202a via a pipe 14a, a switching unit 15a, and a pipe 16 a. The SC1 liquid supply unit 17 is connected to the processing furnace 202a via a pipe 17a, a switching unit 15b, and a pipe 16 b. The DIW supply unit 18 is connected to the process furnace 202a via a pipe 18a, a switching unit 15c, and a pipe 21. The cleaning liquid supply unit 22 is connected to the switching unit 15a, the switching unit 15b, and the switching unit 15c via pipes 22a,22b, and 22c, respectively.

Therefore, the DHF supply unit 14 supplies DHF into the processing furnace 202a via the pipe 14a, the switching unit 15a, and the pipe 16a, and by switching the switching unit 15a to the cleaning liquid supply unit 22 side, supply of DHF into the processing furnace 202a is stopped, and the cleaning liquid contained in the cleaning liquid supply unit 22 is supplied into the processing furnace 202a via the pipe 22a, the switching unit 15a, and the pipe 16 a.

The SC1 liquid supply unit 17 supplies the SC1 liquid into the processing furnace 202a via the pipe 17a, the switch 15b, and the pipe 16b, and switches the switch 15b to the cleaning liquid supply unit 22 side to stop supplying the SC1 liquid into the processing furnace 202a, whereby the cleaning liquid contained in the cleaning liquid supply unit 22 is supplied into the processing furnace 202a via the pipe 22b, the switch 15b, and the pipe 16 b.

The DIW supply unit 18 supplies DIW into the processing furnace 202a via the pipe 18a, the switching unit 15c, and the pipe 21, and switches the switching unit 15c to the cleaning liquid supply unit 22 side to stop the supply of DIW into the processing furnace 202a, whereby the cleaning liquid of the cleaning liquid supply unit 22 is supplied into the processing furnace 202a via the pipe 22c, the switching unit 15c, and the pipe 21.

Fig. 3 is a vertical sectional view for explaining the structure of the treatment furnace 202 a.

A cleaning chamber 30 as a first process chamber is formed in the process furnace 202 a. The cleaning chamber 30 has a holder 34 therein for horizontally holding the wafer 200. The holder 34 is connected to a rotation mechanism 36 such as a motor via a rotation shaft 37, and the wafer 200 horizontally supported by the rotation mechanism 36 is rotated.

The support 34 is surrounded by a shroud 38. As described later, when the wafer 200 is rotated by the holder 34, the hood 38 blocks the chemical solution splashed from the wafer 200.

A substrate transfer port 33 (see fig. 2) is formed in a side surface of the processing furnace 202 a. A gate valve 70a (see fig. 1 and 2) is provided in the substrate carrying-in/out port 33, and the substrate carrying-in/out port 33 is opened and closed by the gate valve 70 a. The first substrate transfer unit 112 is configured to transfer the wafer 200 to the support 34 through the substrate loading/unloading port 33.

The cleaning chamber 30 is inserted with the nozzle 40 and the nozzle 42. The nozzle 40 is connected to a pipe 16a for supplying DHF and a pipe 16b for supplying SC1 liquid into the cleaning chamber 30. The nozzle 42 is connected to a pipe 21 for supplying DIW into the cleaning chamber 30. The nozzles 40 and 42 are arranged generally horizontally with their respective front ends extending to near the center of the wafer 200 supported by the support 34. Accordingly, the DHF and SC1 liquids are supplied from the nozzle 40 to the center of the wafer 200 through the pipes 16a and 16b, respectively. DIW is supplied from the nozzle 42 to the center of the wafer 200 through the pipe 21. Further, by switching the switching portion 15a,15b, or 15c to the cleaning liquid supply portion 22 side, the cleaning liquid is supplied into the pipe 16a, the pipe 16b, or the pipe 21 and is supplied into the cleaning chamber 30 from at least one of or both of the nozzle 40 and the nozzle 42.

The water supply unit 50 is configured to be opened around the inner upper portion of the cover 38 and to be capable of supplying pure water (deionized water) to the inner surface of the cover 38.

The drain pipe 54 for discharging the pure water supplied to the hood 38 is connected to the lower surface of the hood 38, and the drain pipe 54 extends to the outside of the treatment furnace 202a, and the pure water in the hood 38 is discharged through the drain pipe 54. The chemical solution and rinse solution supplied to the wafer 200 are also discharged through the drain pipe 54.

The upper portion of the processing furnace 202a is connected to the drying gas supply pipe 56. As the drying gas, for example, nitrogen (N) is used₂). Further, the lower portion of the treatment furnace 202a is connected to an exhaust pipe 60 for discharging the drying gas.

The first gas supply system for supplying DHF as the first inorganic material is mainly composed of a DHF supply unit 14, a pipe 14a, a switching unit 15a, a pipe 16a, and a nozzle 40. The second gas supply system for supplying the oxidizing agent is composed of the SC1 liquid supply unit 17, the pipe 17a, the switching unit 15b, the pipe 16b, and the nozzle 40. The DIW supply system for supplying DIW includes a DIW supply unit 18, a pipe 18a, a switching unit 15c, a pipe 21, and a nozzle 42. It is also contemplated that the DIW supply system may be incorporated into the first gas supply system or the second gas supply system. The cleaning liquid supply system for supplying the cleaning liquid is composed of the cleaning liquid supply unit 22, the pipes 22a to 22c, the switching units 15a to 15c, the pipes 16a,16b,21, and the nozzles 40, 42.

(constitution of treatment furnace 202 b)

Fig. 4 is a schematic configuration diagram of a processing furnace 202b as a second process unit included in the substrate processing apparatus 10, and fig. 5 is a longitudinal sectional view of the processing furnace 202 b.

The processing furnace 202b serves as a modification (pretreatment) unit that performs a modification process (pretreatment) before the film formation process. The processing furnace 202b is a batch type processing furnace that processes a plurality of wafers at a time.

The processing furnace 202b has a heater 207 as a heating device (heating mechanism, heating system). The heater 207 has a cylindrical shape and is vertically mounted while being supported by a heater base (not shown) as a holding plate.

An outer tube 203 constituting a reaction vessel (processing vessel) is disposed concentrically with the heater 207 inside the heater 207. The outer tube 203 is made of, for example, quartz (SiO)₂) And silicon carbide (SiC) or the like, and is formed into a cylindrical shape having an upper end closed and a lower end open. A header (inlet flange) 209 is disposed below the outer tube 203 concentrically with the outer tube 203. The header 209 is made of metal such as stainless steel (SUS), and is formed in a cylindrical shape with an upper end and a lower end opened. An O-ring 220a as a sealing member is provided between the upper end of the manifold 209 and the outer tube 203. The header 209 is supported by the heater base, so that the outer tube 203 is vertically mounted.

An inner tube 204 constituting a reaction vessel is disposed inside the outer tube 203. The inner tube 204 is made of, for example, quartz (SiO)₂) And silicon carbide (SiC) or the like, and is formed into a cylindrical shape having an upper end closed and a lower end open. The processing vessel (reaction vessel) is mainly composed of an outer tube 203, an inner tube 204, and a collecting tube 209. A processing chamber 201b as a second processing chamber is formed in the hollow portion of the processing container (inside the inner tube 204).

The processing chamber 201b is configured to be able to accommodate wafers 200 as substrates in a state where wafer cassettes 217, which will be described later, are arranged in a plurality of stages in the vertical direction in a horizontal posture.

In the processing chamber 201b, a nozzle 410 is provided so as to penetrate the side wall of the manifold 209 and the inner pipe 204. The nozzle 410 is connected to the gas supply pipe 310. However, the treatment furnace 202b of the present embodiment is not limited to the above-described embodiment.

A Mass Flow Controller (MFC)312 as a flow rate controller (flow rate control unit) and a valve 314 as an on-off valve are provided in this order from the upstream side in the gas supply pipe 310. The downstream side of the valve 314 of the gas supply pipe 310 is connected to a gas supply pipe 510 for supplying an inert gas. In the gas supply pipe 510, an MFC512 and a valve 514 are provided in this order from the upstream side.

The tip of the gas supply pipe 310 is connected to the nozzle 410. The nozzle 410 is an L-shaped nozzle, and a horizontal portion thereof is provided so as to penetrate the side wall of the header 209 and the inner pipe 204. The vertical portion of the nozzle 410 is provided inside a channel-shaped (groove-shaped) preliminary chamber 205b formed to protrude outward in the radial direction of the inner tube 204 and extend in the vertical direction, and is provided upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner tube 204 in the preliminary chamber 205 b.

The nozzle 410 is provided to extend from a lower region of the processing chamber 201b to an upper region of the processing chamber 201b, and a plurality of gas supply holes 410a are provided at positions facing the wafer 200. Thereby, the process gas is supplied from the gas supply hole 410a of the nozzle 410 to the wafer 200. The plurality of gas supply holes 410a are provided continuously from the lower portion to the upper portion of the inner tube 204, have the same opening area, and are provided at the same pitch. The gas supply hole 410a is not limited to the above. For example, the opening area may be gradually increased from the lower portion toward the upper portion of the inner tube 204. This makes it possible to further uniformize the flow rate of the gas supplied from the gas supply hole 410 a.

A plurality of gas supply holes 410a of the nozzle 410 are provided at a height from a lower portion to an upper portion of a wafer cassette 217 described later. Therefore, the process gas supplied from the gas supply hole 410a of the nozzle 410 into the process chamber 201b is supplied to the entire region of the wafer 200 accommodated from the lower portion to the upper portion of the wafer cassette 217. The nozzle 410 may be provided to extend from a lower region to an upper region of the processing chamber 201b, and preferably extends to a position near the top of the wafer cassette 217.

The second halogen material (halide) as the second inorganic material is supplied from the gas supply pipe 310 into the processing chamber 201b through the MFC312, the valve 314, and the nozzle 410 as the reformed gas. AsAs the modifying gas, for example, a fluorine (F) -containing gas having an electronegative ligand can be used, and as an example, chlorine trifluoride (ClF) can be used₃). The reformed gas is used as an adsorption control agent for controlling adsorption of the stacking gas, which will be described later.

Nitrogen (N) as an inert gas is supplied from the gas supply pipe 510 through the MFC512, the valve 514, and the nozzle 410₂) The gas is supplied into the processing chamber 201 b. Hereinafter, N is used as the inert gas₂The gas is exemplified, but the inert gas is not limited to N₂In addition to the gas, an inert gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas may be used.

The third gas supply system (reformed gas supply system) for supplying the reformed gas as the second inorganic material is mainly composed of the gas supply pipe 310, the MFC312, the valve 314, and the nozzle 410, but only the nozzle 410 may be considered as the third gas supply system. The inert gas supply system is mainly composed of a gas supply pipe 510, an MFC512, and a valve 514. It is also contemplated that the inert gas supply system may be incorporated into the third gas supply system.

In the gas supply method according to the present embodiment, the gas is transported through the nozzle 410, and the nozzle 410 is disposed in the preliminary chamber 205b in the annular vertical space defined by the inner wall of the inner tube 204 and the end portions of the plurality of wafers 200. Then, gas is ejected into the inner pipe 204 from a plurality of gas supply holes 410a provided at positions of the nozzle 410 facing the wafer. More specifically, the reformed gas or the like is ejected from the gas supply hole 410a of the nozzle 410 in a direction parallel to the surface of the wafer 200.

The exhaust hole (exhaust port) 204a is a through hole formed in the side wall of the inner tube 204 at a position facing the nozzle 410, and is, for example, a vertically elongated slit-shaped through hole. The gas supplied from the gas supply hole 410a of the nozzle 410 into the processing chamber 201b and flowing on the surface of the wafer 200 flows into the exhaust passage 206 formed by the gap formed between the inner tube 204 and the outer tube 203 via the exhaust hole 204 a. Then, the gas flowing into the exhaust passage 206 flows into the exhaust pipe 231 and is discharged to the outside of the processing furnace 202 b.

The exhaust hole 204a is provided at a position facing the plurality of wafers 200, and the gas supplied from the gas supply hole 410a to the vicinity of the wafers 200 in the processing chamber 201b flows in the horizontal direction and then flows into the exhaust path 206 through the exhaust hole 204 a. The exhaust hole 204a is not limited to a slit-shaped through hole, and may be formed of a plurality of holes.

The manifold 209 is provided with an exhaust pipe 231 for exhausting the atmosphere in the processing chamber 201 b. The exhaust pipe 231 is connected to a Pressure sensor 245 as a Pressure detector (Pressure detecting unit) for detecting the Pressure in the processing chamber 201b, an APC (automatic Pressure Controller) valve 243, and a vacuum pump 246 as a vacuum exhaust device in this order from the upstream side. The APC valve 243 can perform vacuum evacuation and stop vacuum evacuation in the processing chamber 201b by opening and closing the valve in the operating state of the vacuum pump 246, and can adjust the pressure in the processing chamber 201b by adjusting the valve opening degree in the operating state of the vacuum pump 246. The exhaust system is mainly constituted by an exhaust hole 204a, an exhaust passage 206, an exhaust pipe 231, an APC valve 243, and a pressure sensor 245. It is also contemplated that the vacuum pump 246 may be incorporated into the exhaust system.

A seal cap 219 serving as a furnace opening lid body capable of hermetically closing the lower end opening of the header 209 is provided below the header 209. The seal cap 219 is configured to abut against the lower end of the header 209 from the vertical direction lower side. The seal cap 219 is made of metal such as SUS, and is formed in a disk shape. An O-ring 220b as a sealing member is provided on the upper surface of the seal cap 219 to be in contact with the lower end of the manifold 209. A rotation mechanism 267 for rotating the wafer cassette 217 accommodating the wafer 200 is provided on the side of the sealing cap 219 opposite to the process chamber 201 b. The rotary shaft 255 of the rotary mechanism 267 penetrates the seal cap 219 and is connected to the wafer cassette 217. The rotating mechanism 267 is configured to rotate the wafer 200 by rotating the pod 217. The sealing cap 219 is configured to be vertically lifted by a cassette lifter 115 as a lifting mechanism provided vertically outside the reaction tube 203. The cassette lifter 115 is configured to move the cassette 217 into and out of the processing chamber 201b by lifting and lowering the seal cap 219. The pod lifter 115 is configured as a transfer device (transfer mechanism) that transfers the pod 217 and the wafer 200 accommodated in the pod 217 into and out of the processing chamber 201 b.

The wafer cassette 217 as a substrate support is configured to be able to arrange a plurality of wafers 200 (for example, 25 to 200 wafers) in a horizontal posture with their centers aligned with each other at intervals in a vertical direction. The wafer cassette 217 is made of a heat-resistant material such as quartz or SiC. A heat shield plate 218 made of a heat-resistant material such as quartz or SiC is supported in a horizontal posture in multiple stages (not shown) at the lower portion of the wafer cassette 217. With this configuration, heat from the heater 207 is less likely to be conducted to the sealing cap 219 side. However, the present embodiment is not limited to the above embodiment. For example, instead of providing the heat insulating plate 218 at the lower portion of the wafer cassette 217, a heat insulating cylinder formed as a cylindrical member made of a heat-resistant material such as quartz or SiC may be provided.

As shown in fig. 5, a temperature sensor 263 as a temperature detector is provided in the inner tube 204, and the temperature in the processing chamber 201b is set to a desired temperature distribution by adjusting the amount of current supplied to the heater 207 based on the temperature information detected by the temperature sensor 263. The temperature sensor 263 is formed in an L-shape similarly to the nozzle 410, and is provided along the inner wall of the inner tube 204.

(constitution of treatment furnace 202 c)

Fig. 6 is a longitudinal sectional view of a processing furnace 202c as a third process unit included in the substrate processing apparatus 10, and fig. 7 is a top sectional view of the processing furnace 202 c. The processing furnace 202c has a processing chamber 201c as a third processing chamber. The processing furnace 202c in the present embodiment is different from the processing furnace 202b and the structure inside the processing chamber 201. Only the portions of the processing furnace 202c different from the processing furnace 202b described above will be described below, and the description of the same portions will be omitted.

The processing furnace 202c functions as a film formation unit for performing a film formation process.

In the process chamber 201c, nozzles 420,430 are provided through the side wall of the header 209 and the inner pipe 204. The nozzles 420,430 are connected to the gas supply pipes 320,330, respectively.

In the gas supply pipes 320 and 330, an MFC322,332 and valves 324 and 334 are provided in this order from the upstream side. Gas supply pipes 520 and 530 for supplying an inert gas are connected to the downstream sides of the valves 324 and 334 of the gas supply pipes 320 and 330, respectively. MFCs 522 and 532 and valves 524 and 534 are provided in the gas supply pipes 520 and 530 in this order from the upstream side.

The gas supply pipes 320 and 330 are connected to the nozzles 420 and 430 at their distal ends, respectively. The nozzles 420,430 are formed as L-shaped nozzles, and the horizontal portions thereof are provided to penetrate the side wall of the header 209 and the inner pipe 204. The vertical portions of the nozzles 420,430 are disposed inside the preliminary chamber 205c formed in a channel shape (groove shape) protruding outward in the radial direction of the inner tube 204 and extending in the vertical direction, and are disposed upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner tube 204 in the preliminary chamber 205 c.

The nozzles 420 and 430 are provided to extend from a lower region of the process chamber 201c to an upper region of the process chamber 201c, and a plurality of gas supply holes 420a and 430a are provided at positions facing the wafer 200, respectively.

The plurality of gas supply holes 420a,430a of the nozzles 420,430 are provided at a height from a lower portion to an upper portion of the wafer cassette 217 described later. Thus, the process gas supplied into the process chamber 201c from the gas supply holes 420a,430a of the nozzles 420,430 is supplied to the entire region of the wafer 200 accommodated from the lower portion to the upper portion of the pod 217.

A source gas, which is a deposition gas, is supplied from a gas supply pipe 320 into the process chamber 201c as a process gas through the MFC322, the valve 324, and the nozzle 420. The source gas may be, for example, a third halogen-based material, a chlorine (Cl) -containing gas containing chlorine (Cl) having an electrically negative ligand, or the like, and silicon tetrachloride (SiCl) may be used as an example thereof₄) A gas.

A reaction gas that reacts with the source gas as the deposition gas is supplied from the gas supply pipe 330 into the process chamber 201c through the MFC332, the valve 334, and the nozzle 430 as a process gas. As the reaction gas, for example, an N-containing gas containing nitrogen (N) may be used, and as an example thereof, ammonia (NH) may be used₃) A gas.

Nitrogen (N) as an inert gas is supplied from the gas supply pipes 520,530 through the MFCs 522,532, valves 524,534, and nozzles 420,430, respectively₂) Gas (es)Is supplied into the processing chamber 201 c.

The fourth gas supply system (deposition gas supply system) for supplying the deposition gas is mainly composed of the gas supply pipes 320 and 330, the MFC322,332, the valves 324 and 334, and the nozzles 420 and 430, and only the nozzles 420 and 430 may be considered as the fourth gas supply system. When the source gas flows through the gas supply pipe 320, the source gas supply system is mainly composed of the gas supply pipe 320, the MFC322, and the valve 324, and it is also conceivable to incorporate the nozzle 420 into the source gas supply system. When the reaction gas flows through the gas supply pipe 330, the reaction gas supply system is mainly composed of the gas supply pipe 330, the MFC332, and the valve 334, and it is also possible to consider incorporating the nozzle 430 into the reaction gas supply system. When the nitrogen-containing gas is supplied as the reaction gas from the gas supply pipe 330, the reaction gas supply system may be referred to as a nitrogen-containing gas supply system. Further, the inert gas supply system is mainly constituted by gas supply pipes 520 and 530, MFCs 522 and 532, and valves 524 and 534. It is also contemplated to incorporate the inert gas supply system into the fourth gas supply system.

(constitution of treatment furnace 202 d)

The treatment furnace 202d in the present embodiment has the same configuration as the treatment furnace 202b shown in fig. 4. The processing furnace 202d has a processing chamber 201d as a fourth processing chamber.

The processing furnace 202d serves as an etching unit for performing an etching process.

In the process chamber 201d, the nozzle 440 is provided so as to penetrate the side wall of the manifold 209 and the inner pipe 204. The nozzle 440 is connected to the gas supply pipe 340.

An MFC342 and a valve 344 are provided in this order from the upstream side in the gas supply pipe 340. The downstream side of the valve 344 of the gas supply pipe 340 is connected to a gas supply pipe 540 for supplying an inert gas. In the gas supply pipe 540, an MFC542 and a valve 544 are provided in this order from the upstream side.

The tip of the gas supply pipe 340 is connected to the nozzle 440. The nozzle 440 is an L-shaped nozzle, and a horizontal portion thereof is provided to penetrate the side wall of the header 209 and the inner pipe 204. The vertical portion of the nozzle 440 is provided inside the preliminary chamber 205d formed in a channel shape (groove shape) protruding outward in the radial direction of the inner tube 204 and extending in the vertical direction, and is provided inside the preliminary chamber 205d so as to face upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner tube 204.

The nozzle 440 is provided to extend from a lower region of the processing chamber 201d to an upper region of the processing chamber 201d, and a plurality of gas supply holes 440a are provided at positions facing the wafer 200.

The plurality of gas supply holes 440a of the nozzle 440 are provided at a height position from a lower portion to an upper portion of the wafer cassette 217 described later. Thereby, the process gas supplied into the process chamber 201d from the gas supply hole 440a of the nozzle 440 is supplied to the entire region of the wafer 200 accommodated from the lower portion to the upper portion of the wafer cassette 217.

An etching gas is supplied from the gas supply pipe 340 into the processing chamber 201d through the MFC342, the valve 344, and the nozzle 440. As the etching gas, for example, chlorine trifluoride (ClF) can be used₃)。

Nitrogen (N) as an inert gas is supplied from the gas supply pipe 540 through the MFC542, the valve 544, and the nozzle 440, respectively₂) The gas is supplied into the processing chamber 201 d.

The fifth gas supply system (etching gas supply system) is mainly composed of the gas supply pipe 340, the MFC342, the valve 344, and the nozzle 440, and only the nozzle 440 may be considered as the fifth gas supply system. The fifth gas supply system may also be referred to as a process gas supply system, or simply as a gas supply system. The inert gas supply system is mainly composed of a gas supply pipe 540, an MFC542, and a valve 544. It is also contemplated that the inert gas supply system may be incorporated into the fifth gas supply system.

(constitution of control section)

As shown in fig. 8, the controller 121 as a control Unit (control means) is configured as a computer having a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I/O interface 121 d. The RAM121b, the storage device 121c, and the I/O interface 121d are configured to be able to exchange data with the CPU121a via the internal bus 121 e. The controller 121 is connected to an input/output device 122 configured as a touch panel or the like, for example.

The storage device 121c is configured by, for example, a flash memory, an HDD (Hard Disk Drive), or the like. The memory device 121c stores therein a control program for controlling the operation of the substrate processing apparatus, and can read out a process recipe, such as a process and a condition of a method for manufacturing a semiconductor device, which will be described later. The process recipe is a combination of processes (steps) in a method of manufacturing a semiconductor device described later and a predetermined result is obtained by causing the controller 121 to execute the processes, and functions as a program. Hereinafter, the process recipe, the control program, and the like are also referred to simply as a program. When the term "process" is used herein, it includes the case of a single process recipe alone, the case of a single control process alone, and the case of a combination of a process recipe and a control process. The RAM121b is configured as a storage area (work area) for temporarily storing programs, data, and the like read out by the CPU121 a.

The I/O interface 121d is connected to the first substrate transfer unit 112, the gate valves 70a to 70d, the rotation mechanism 36, the switching units 15a to 15c, the MFC312,322,332,342,512,522,532,542, the valve 314,324,334,344,514,524,534,544, the pressure sensor 245, the APC valve 243, the vacuum pump 246, the heater 207, the temperature sensor 263, the rotation mechanism 267, the cassette lifter 115, and the like.

The CPU121a is configured to read out and execute a control program from the storage device 121c, and read out a recipe and the like from the storage device 121c in response to input of an operation command and the like from the input/output device 122.

The CPU121a is configured to control the rotation of the support 34 by the rotation mechanism 36, the opening and closing of the gate valves 70a to 70d, the carrying in and out of the wafer 200 by the first substrate transfer 112, the supply of the DHF and SC1 liquid by the nozzle 40, the supply of the DIW by the nozzle 42, the supply of the cleaning liquid to the pipes 16a,16b,21, the switching operations of the switching units 15a,15b,15c, the supply of the deionized water from the water supply unit 50, and the supply of the nitrogen (N) from the drying gas supply pipe 56 in accordance with the contents of the read recipe₂) Supply of (2), etc.

The CPU121a is configured to control flow rate adjustment operations of various gases by the MFC312,322,332,342,512,522,532,542, an opening/closing operation of the valve 314,324,334,344,514,524,534,544, an opening/closing operation of the APC valve 243, a pressure adjustment operation by the APC valve 243 based on the pressure sensor 245, a temperature adjustment operation of the heater 207 based on the temperature sensor 263, start and stop of the vacuum pump 246, rotation and rotation speed adjustment operations of the cassette 217 by the rotation mechanism 267, a lifting/lowering operation of the cassette 217 by the cassette lifter 115, a storing operation of the wafer 200 in the cassette 217, and the like, in accordance with the contents of the read recipe.

That is, the controller 121 is configured to control the transfer system such as the first substrate transfer device 121, the first gas supply system and the second gas supply system of the processing furnace 202a, the third gas supply system of the processing furnace 202b, the fourth gas supply system of the processing furnace 202c, the fifth gas supply system of the processing furnace 202d, and the like.

The controller 121 may be configured by installing the program stored in the external storage device 123 (for example, a magnetic tape, a magnetic disk such as a flexible disk or a hard disk, an optical disk such as a CD or a DVD, an optical magnetic disk such as an MO, a USB memory, a semiconductor memory such as a memory card, or the like) into a computer. The storage device 121c and the external storage device 123 constitute a computer-readable recording medium. Hereinafter, these will be collectively referred to simply as recording media. In this specification, the recording medium sometimes includes only the separate storage device 121c, sometimes includes only the separate external storage device 123, or sometimes includes both of them. The program can be supplied to the computer by using the internet or a private line communication method without using the external storage device 123.

(2) Substrate processing procedure

As one of the steps of manufacturing the semiconductor device (equipment), a semiconductor device having a silicon (Si) layer and silicon oxide (SiO) on the surface thereof was fabricated using fig. 9 to 12₂) An example of a process for forming a SiN film on a SiN layer on a wafer 200 of layers and a silicon nitride (SiN) layer will be described. In this step, the natural oxide film is removed from the surface of the wafer 200 in the processing furnace 202a, and a process of forming an oxide film again on the Si layer of the wafer 200 is performed. Then, the Si layer is formed on the wafer 200 in the processing furnace 202bSurface and SiO₂And (5) modifying the surface of the layer. Then, a process of selectively growing a SiN film on the SiN layer of the wafer 200 is performed in the process furnace 202 c. Then, the process is performed in the processing furnace 202d for the surface of the Si layer of the wafer 200 and the SiO₂And etching the SiN film formed on the surface of the layer slightly. In the following description, the controller 121 controls the operations of the respective parts constituting the substrate processing apparatus 10.

In the substrate processing step (semiconductor device manufacturing step) of the present embodiment, the following steps are sequentially performed:

a step of supplying DHF as a first inorganic material to the wafer 200 having at least an Si film as a first film and an SiN film as a second film different from the first film exposed on the surface thereof, and removing a natural oxide film from the surface of the wafer 200,

supplying SC1 solution as an oxidizing agent to the wafer 200 to oxidize the Si film and form an oxide film on the surface,

ClF as a second inorganic material is supplied to the wafer 200₃Gas, a step of modifying the surface of the Si film, and

SiCl as a deposition gas is supplied to the wafer 200₄Gas and NH₃And a step of selectively growing a thin SiN film on the surface of the SiN film by using a gas.

Further, an etching gas is supplied to the wafer 200 to etch the SiN film formed on the surface of the Si layer.

In the present specification, the term "wafer" includes a case of "wafer itself" and a case of "a laminated body of a wafer and a predetermined layer, film, or the like formed on the surface of the wafer". In the present specification, the term "wafer surface" is used to include a case of "the surface of the wafer" and a case of "the surface of a predetermined layer, film, or the like formed on the wafer". In the present specification, the term "substrate" is used in the same sense as the term "wafer".

A. Cleaning treatment (cleaning process)

First, the first step isThe processing furnace 202a of the process unit is loaded with a Si layer and SiO layer on the surface₂The wafer 200 of layers and SiN layer is subjected to a process of removing a natural oxide film and a process of forming an oxide film again on the surface of the Si layer.

(wafer carrying in)

The substrate carrying-in/out port 33 is opened by the gate valve 70a, and the patterned Si layer or SiO layer is carried on the surface by the first substrate transfer unit 112₂The wafer 200 with the layer and the SiN layer is carried into the cleaning chamber 30.

Subsequently, the first substrate transfer unit 112 is further controlled to support (mount) the wafer 200 on the support 34, and the substrate transfer port 33 is closed by the gate valve 70 a.

Subsequently, the rotation mechanism 36 rotates the holder 34 via the rotation shaft 37, thereby starting the rotation of the wafer 200.

A-1: [ Natural oxide film removal Process ]

First, a process of removing a natural oxide film from the surface of the wafer 200 is performed in the process furnace 202 a.

(DHF cleaning: step S10)

While maintaining the rotation of the wafer 200, the switching unit 15a is switched to the DHF supply unit 14 side, and DHF is supplied from the nozzle 40 through the pipe 16a, thereby cleaning the surface of the wafer 200.

(DIW rinse: step S11)

Next, while the rotation of the wafer 200 is maintained, the supply of DHF from the nozzle 40 is stopped, the switching unit 15c is switched to the DIW supply unit 18 side, DIW as a rinse liquid is supplied from the nozzle 42 to the center of the wafer 200 through the pipe 21, and DHF remaining on the wafer surface is rinsed.

Then, the rotation of the wafer 200 is maintained, and the supply of DIW from the nozzle 42 is stopped, and the DIW and the like on the wafer are spun off by the centrifugal force of the rotation.

(drying: step S12)

Subsequently, N is supplied as a drying gas to the cleaning chamber 30 through the drying gas supply pipe 56₂While exhausting air from the exhaust pipe 54, the cleaning chamber 30 is changed to N₂Atmosphere of N in₂The wafer 200 is dried in an atmosphere. It is to be noted thatIt is preferable to continuously supply water from the water supply unit 50 to the inner surface of the cover 38 with high safety until DHF cleaning in step S10, DIW rinsing in step S11, and drying in step S12. That is, pure water may be supplied to the inner surface of the cover 38 at least while DHF, DIW, and the like are splashed from the wafer 200 to the cover 38. Pure water may be supplied to the inner surface of cap 38 in the oxide film reforming step described later.

Subsequently, after the surface of the wafer 200 is dried, the supply of N into the cleaning chamber 30 is stopped₂。

Through the above steps, as shown in fig. 10 (a), the Si layer and SiO layer are formed on the wafer₂A natural oxide film, organic deposits, and the like formed on the surface of the layer and the SiN layer are removed. That is, at this time, the natural oxide film on the Si layer is also removed.

A-2: [ oxide film reforming step ]

Next, the Si layer on the wafer 200 is oxidized, and an oxide film is formed again on the surface.

(APM (ammonium Peroxide Mixture of Ammonia and hydrogen Peroxide) cleaning (SC1 cleaning): S13)

While the rotation of the wafer 200 is maintained, the switching unit 15b is switched to the SC1 liquid supply unit 17 side, and the SC1 liquid is supplied from the nozzle 40 through the pipe 16b, thereby cleaning the surface of the wafer 200. By supplying the SC1 solution, as shown in fig. 10 (B), the Si layer surface is preferentially oxidized by chemical action to form a thin oxide film (SiO) of about 1nm₂A film). Then, SiO on the surface of the Si layer₂Film surface and SiO₂The surface of the layer forms an OH terminal. In this case, the SiN layer surface is hard to be oxidized, and H molecules remain. Further, by adjusting the concentration and the supply time of each of the components contained in the SC1 solution, the thickness of the oxide film formed on the surface of the Si layer can be controlled. At this time, the SiN layer surface is hardly oxidized and no oxide film is formed. The surface of the Si layer is coated with the thin oxide film by chemical action, and thus direct damage to the surface of the Si layer can be prevented by the modification treatment with the F-containing gas performed in the subsequent step.

(DIW rinse: S14)

Next, while the rotation of the wafer 200 is maintained, the supply of the SC1 liquid from the nozzle 40 is stopped, the switch 15c is switched to the DIW supply unit 18, DIW as a rinse liquid is supplied from the nozzle 42 to the center of the wafer 200 through the pipe 21, and the SC1 liquid remaining on the wafer surface is washed away and rinsed.

Then, the supply of DIW from the nozzle 42 is stopped while the rotation of the wafer 200 is maintained, and the DIW and the like on the wafer are spun off by the centrifugal force of the rotation.

(drying: S15)

Subsequently, N is supplied as a drying gas to the cleaning chamber 30 through the drying gas supply pipe 56₂While exhausting air from the exhaust pipe 54, the cleaning chamber 30 is changed to N₂Atmosphere of N in₂The wafer 200 is dried in an atmosphere.

Then, the rotation of the holder 34 by the rotation mechanism 36 is stopped, and the rotation of the wafer 200 is stopped. Further, the supply of N into the cleaning chamber 30 is stopped₂。

Subsequently, the substrate transfer port 33 is opened by the gate valve 70a, and the wafer 200 is transferred from the cleaning chamber 30 by the first substrate transfer unit 112.

Through the above steps, the oxide film formed on the surface of the Si layer functions as a protective film for the Si layer, and exposure to ClF in the subsequent modification step can be suppressed₃Etching of the Si layer by F component contained in the gas.

B. Modification (Pre) treatment (Pre-modification step)

Next, the wafer 200 is carried into the processing furnace 202b as the second process unit, and the SiO layer on the Si layer formed in the cleaning process is removed₂Film surface and SiO₂On the surface of the layer, a reforming treatment is performed to supply a reforming gas as an adsorption control agent for suppressing adsorption of the raw material gas.

(wafer carrying in)

After loading a plurality of wafers 200 into the cassette 217 (wafer loading), as shown in fig. 4, the cassette 217 supporting the plurality of wafers 200 is lifted up by the cassette lifter 115 and carried into the processing chamber 201b (cassette loading). In this state, the seal cap 219 closes the lower end opening of the reaction tube 203 via the O-ring 220.

(pressure adjustment and temperature adjustment)

The processing chamber 201b is evacuated by the vacuum pump 246 to a desired pressure (vacuum degree). At this time, the pressure in the processing chamber 201b is measured by the pressure sensor 245, and the APC valve 243 is feedback-controlled (pressure-adjusted) based on the measured pressure information. The vacuum pump 246 is maintained in a constantly operating state at least until the end of the processing of the wafer 200. Further, the inside of the processing chamber 201b is heated by the heater 207 to a desired temperature. At this time, the amount of current supplied to the heater 207 is feedback-controlled (temperature-adjusted) based on the temperature information detected by the temperature sensor 263 so that a desired temperature distribution is achieved in the processing chamber 201 b. The heating of the inside of the processing chamber 201b by the heater 207 is continued at least until the end of the processing of the wafer 200.

B-1: [ modified gas supply step ]

(ClF₃Gas supply: step S16)

The valve 314 is opened, and ClF as a reformed gas is introduced into the gas supply pipe 310₃A gas. ClF₃The gas is supplied into the processing chamber 201b from the gas supply hole 410a of the nozzle 410 by adjusting the flow rate of the gas by the MFC312, and is exhausted from the exhaust pipe 231. At this time, ClF is supplied to the wafer 200₃A gas. In parallel with this, the valve 514 is opened, and N flows into the gas supply pipe 510₂And inert gases such as gases. N flowing in the gas supply pipe 510₂Gas flow regulation with the ClF by MFC512₃The gases are supplied into the processing chamber 201b and exhausted from the exhaust pipe 231.

At this time, the pressure in the processing chamber 201b is adjusted to a pressure in the range of, for example, 1 to 1000Pa by adjusting the APC valve 243. ClF controlled by MFC312₃The supply flow rate of the gas is, for example, in the range of 1 to 1000 sccm. N controlled by MFC512₂The supply flow rate of the gas is, for example, in the range of 100 to 10000 sccm. Supplying ClF to wafer 200₃The gas time is, for example, in the range of 1 to 3600 seconds. In this case, the temperature of the heater 207 is set so that the temperature of the wafer 200 is, for example, 30 to 300 ℃, preferably 30 to 250 ℃, more preferably 30 to 200 ℃. For example, 30 to 200 ℃ means 30 ℃ to 200 ℃. The same applies to other numerical ranges below.

The gas flowing in the processing chamber 201b at this time is ClF₃Gas and N₂A gas. As shown in FIG. 10 (C), by ClF₃Supplying gas to form SiO on Si layer of wafer 200₂Film surface and SiO₂H molecules of OH terminals on the surface of the layer are replaced by F molecules to form F terminals, so that the F molecules are adsorbed on the oxide film. At this time, F molecules are hardly adsorbed on the SiN layer of the wafer 200. In addition, the ClF on the surface of the wafer 200 at this time_xHF, etc. are eliminated.

Then, ClF is supplied from the beginning₃After a predetermined time has elapsed since the gas supply, the valve 314 of the gas supply pipe 310 is closed to stop the ClF supply₃A gas.

B-2: [ purging step ]

(residual gas removal: step S17)

Then, the ClF supply is stopped₃After the gas is exhausted, a purge process for exhausting the gas in the processing chamber 201b is performed. At this time, the APC valve 243 of the exhaust pipe 231 is kept open, and the inside of the processing chamber 201b is vacuum-exhausted by the vacuum pump 246 to remove unreacted ClF remaining in the processing chamber 201b₃Gas or ClF after adsorbing F molecules on oxide film₃Gas, ClF_xGas, HF gas, and the like are exhausted from the processing chamber 201 b. At this time, the supply of N into the processing chamber 201b is maintained with the valve 514 kept open₂A gas. N is a radical of₂The gas functions as a purge gas, and unreacted ClF remaining in the processing chamber 201b can be increased₃ClF after adsorption of F molecules on gas or oxide film₃The effect of gas evacuation from the process chamber 201 b.

(Perform a predetermined number of times: step S18)

By performing the cycle of the above-described steps S16 and S17 1 or more times (predetermined times (m times)), F molecules are adsorbed on the oxide film formed on the Si layer surface of the wafer 200. In addition, F molecules are not adsorbed on the SiN layer surface of the wafer 200.

(post purge and atmospheric pressure recovery)

N is supplied into the processing chamber 201b from the gas supply pipe 510₂The gas is exhausted from the exhaust pipe 231. N is a radical of₂The gas functions as a purge gas, whereby the inside of the processing chamber 201b is purged with an inert gas, and the gas and by-products remaining in the processing chamber 201b are removed from the inside of the processing chamber 201b (post-purge). Then, the atmosphere in the processing chamber 201b is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201b is returned to normal pressure (atmospheric pressure return).

(wafer carry-out)

Then, the sealing cap 219 is lowered by the cassette lifter 115, and the lower end of the reaction tube 203 is opened. Then, the wafer 200 after the reforming treatment is carried out from the lower end of the reaction tube 203 to the outside of the reaction tube 203 while being supported by the cassette 217 (cassette detachment). Then, the wafer 200 after the modification processing is taken out from the wafer cassette 217 (wafer unloading).

C. Film formation treatment (film formation (Selective growth) step)

Next, the wafer 200 is carried into the processing furnace 202c as the third process unit, and a process of selectively growing a nitride film as a thin film on the surface of the SiN layer is performed.

In the process furnace 202c, a film formation process is performed by adjusting the pressure and the temperature so that a desired pressure and a desired temperature distribution are achieved in the process chamber 201 c. The present step differs from the step in the treatment furnace 202b only in the gas supply step. Hereinafter, only the portions different from the steps in the above-described processing furnace 202b will be described below, and the description of the same portions will be omitted.

C-1: [ first step ]

(raw material gas supply: step S19)

SiCl as a raw material gas was flowed into the gas supply pipe 320 by opening the valve 324₄A gas. SiCl₄The gas is supplied into the processing chamber 201c from the gas supply hole 420a of the nozzle 420 by adjusting the flow rate of the gas by the MFC322, and is exhausted from the exhaust pipe 231. At this time, for the wafer200 supply SiCl₄A gas. In parallel with this, the valve 524 is opened, and N flows into the gas supply pipe 520₂And inert gases such as gases. N flowing in the gas supply pipe 520₂Gas flow regulation by MFC522 with SiCl₄The gases are supplied into the processing chamber 201c and exhausted from the exhaust pipe 231. At this time, to prevent SiCl₄The gas enters the nozzle 430, the valve 534 is opened, and N flows into the gas supply pipe 530₂A gas. N is a radical of₂The gas is supplied into the processing chamber 201c through the gas supply pipe 330 and the nozzle 430, and is exhausted from the exhaust pipe 231.

At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201c is, for example, in the range of 1 to 1000Pa, for example, 100 Pa. SiCl controlled by MFC322₄The supply flow rate of the gas is, for example, in the range of 0.05 to 5 slm. N controlled by MFC522,532₂The supply flow rates of the gases are, for example, in the range of 0.1 to 10 slm. Supplying SiCl to the wafer 200₄The gas time is, for example, in the range of 0.1 to 1000 seconds. At this time, the temperature of the heater 207 is set such that the temperature of the wafer 200 is, for example, in the range of 300 to 700 ℃, preferably 300 to 600 ℃, and more preferably 300 to 550 ℃.

The gas flowing in the processing chamber 201c at this time is SiCl₄Gas and N₂A gas. As shown in (A) of FIG. 11, SiCl₄The gas is difficult to adsorb on the oxide film having F molecules adsorbed on the surface in the above modification treatment, and SiCl is hardly adsorbed₄Cl of (2) is exfoliated with SiCl_xIs chemically adsorbed on the SiN layer and reacts as HCl gas to be desorbed. This is because SiCl₄Since the halogen (Cl) contained in the gas and the halogen (F) on the oxide film are electrically negative ligands, they become repulsive factors and are difficult to adsorb. That is, the incubation time on the oxide film becomes long, and the SiN film can be selectively grown on the SiN layer surface other than the oxide film. The "incubation time" herein refers to the time until film growth starts on the wafer surface.

Here, when a thin film is selectively formed on a specific wafer surface, a source gas may be adsorbed on the wafer surface on which film formation is not desired, and undesired film formation may occur. This destroys selectivity. This selective destruction is likely to occur when the adsorption of the source gas molecules to the wafer is generally high. That is, the decrease in adsorption of the source gas molecules to the wafer on which film deposition is not desired generally directly relates to the improvement in selectivity.

The adsorption of the source gas on the wafer surface is caused by the source gas staying on the wafer surface for a certain time due to the interaction between the source molecules and the wafer surface. That is, the adsorption is roughly determined by both the exposure density of the source gas or its decomposition product to the wafer and the electrochemical factor possessed by the wafer itself. Here, the electrochemical factor of the wafer itself is, for example, a surface defect at an atomic level, and is charged by polarization, an electric field, or the like. That is, it can be said that adsorption is easily caused as long as the electrochemical factor on the wafer surface is in a relationship of being easily attracted to the source gas.

That is, as the modifying gas for modifying the surface of the oxide film on the wafer 200, a material containing a molecule having strong adsorption to the oxide film is preferably used. Further, as the modifying gas, a material which does not etch the oxide film even when exposed to a low temperature is preferably used.

As the modifying gas for modifying the surface of the oxide film on the wafer 200, organic and inorganic substances can be considered. The surface modification with an organic substance has low heat resistance, and if the film forming temperature is 500 ℃ or higher, the film fails and adsorption to Si is also released. That is, when the film is formed at a high temperature of 500 ℃ or higher, the selectivity is deteriorated. On the other hand, the surface modification with an inorganic substance has high heat resistance, and even if the film formation temperature is 500 ℃ or higher, the adsorption with Si does not become detached. For example, fluorine (F) is a powerful passivating agent with strong adsorption power.

Therefore, by using, as the modifying gas, an inorganic material such as a halide containing fluorine (F), chlorine (Cl), iodine (I), bromine (Br), or the like, selective growth can be performed using the modifying gas even in a film formed at a high temperature of 500 ℃. For example, when high-temperature film formation is performed, the modification process can be performed at a low temperature of 250 ℃ or lower, and the film formation process as selective growth can be performed at a high temperature of 500 ℃ or higher. Among the halides, halides having high binding energy are particularly preferred. In addition, the F-containing gas has the highest binding energy among halides and has a strong adsorption force.

Further, as the raw material gas for selective growth, a raw material gas having electrically negative molecules is used. Thus, the reformed gases that modify the surface of the oxide film on the wafer 200 repel each other due to the electrically negative halides, and are difficult to bond. The source gas preferably contains only one source molecule such as a metal element or a silicon element. This is because, when two or more raw material molecules are contained, for example, when two Si are contained, the Si — Si bond is cut, and Si and F are bonded, and there is a possibility that the selectivity is deteriorated.

C-2: [ second Process ]

(residual gas removal: step S20)

After the Si-containing layer is formed on the SiN layer, the valve 324 is closed to stop the supply of SiCl₄A gas.

Next, the unreacted SiCl remaining in the processing chamber 201c is introduced into the reaction chamber₄Gases or SiCl contributed to the Si-containing layer after formation₄The gas and the reaction by-products are exhausted from the processing chamber 201 c.

C-3: [ third Process ]

(reaction gas supply: step S21)

After the residual gas in the processing chamber 201c is removed, the valve 334 is opened, and NH as a reaction gas flows into the gas supply pipe 330₃A gas. NH (NH)₃The gas is supplied into the processing chamber 201c from the gas supply hole 430a of the nozzle 430 by adjusting the flow rate of the gas by the MFC332, and is exhausted from the exhaust pipe 231. At this time, NH is supplied to the wafer 200₃A gas. In parallel with this, the valve 534 is opened, and N flows into the gas supply pipe 530₂A gas. N flowing in the gas supply pipe 530₂The gas is flow regulated by MFC 532. N is a radical of₂Gas and NH₃The gases are supplied into the processing chamber 201c and exhausted from the exhaust pipe 231. At this time, to prevent NH₃Gas is injected into the nozzle 420, the valve 524 is opened,n flows into the gas supply pipe 520₂A gas. N is a radical of₂The gas is supplied into the processing chamber 201c through the gas supply pipe 320 and the nozzle 420, and is exhausted from the exhaust pipe 231.

At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201c is, for example, in the range of 100 to 2000Pa, for example, 800 Pa. NH controlled by MFC332₃The supply flow rate of the gas is, for example, in the range of 0.5 to 5 slm. N controlled by MFC522,532₂The supply flow rates of the gases are, for example, in the range of 1 to 10 slm. NH supply to the wafer 200₃The gas time is, for example, in the range of 1 to 300 seconds. The temperature of the heater 207 at this time is set to be equal to SiCl₄The gas supply step is at the same temperature.

At this time, the gas flowing in the processing chamber 201c is only NH₃Gas and N₂A gas. NH as shown in FIG. 11 (B)₃The gas causes a substitution reaction with at least a part of the Si-containing layer formed on the SiN layer of the wafer 200 in the first step. Si and NH contained in the Si-containing layer during the substitution reaction₃N contained in the gas combines to form a SiN film containing Si and N on the SiN layer on the wafer 200. I.e. SiCl_xAnd NH₃React to form Si-N bonds and form a SiN film. Furthermore, the N-H bond is newly SiCl₄Adsorption sites for gases. Moreover, in the absence of SiCl_xSite of (3), NH₃No reaction can occur. That is, the SiN film is not formed on the oxide film of the wafer 200.

C-4: [ fourth Process ]

(residual gas removal: step S22)

After forming the SiN film on the SiN layer, the valve 334 is closed to stop the supply of NH₃A gas.

Subsequently, the unreacted NH remaining in the processing chamber 201c is treated in the same manner as in the first step₃Gas or NH contributed to SiN film after formation₃The gas and the reaction by-products are exhausted from the processing chamber 201 c.

(Perform a predetermined number of times: step S23)

Next, SiCl as a raw material gas is introduced₄Gas andNH as a reaction gas₃The cycle of the steps S19 to S22, which are sequentially performed, is performed 1 or more times (predetermined times (n times)) while alternately supplying the gases without mixing them with each other, thereby forming an SiN film having a predetermined thickness (for example, 0.1 to 10nm) on the SiN layer of the wafer 200. The above cycle is preferably repeated a plurality of times.

(Perform a predetermined number of times: step S24)

As described above, the cycle of the steps 16 to S23 is performed 1 or more times (predetermined times (o) times), and a SiN film (selective SiN film) having a predetermined thickness (for example, 1 to 100nm) is formed on the SiN layer of the wafer 200. At this time, as shown in FIG. 11 (C), SiO is used₂SiO on layer, on Si layer₂On the film, an island-like SiN film is formed slightly due to incompleteness.

D. Etching treatment (etching Process)

Next, as shown in fig. 12 (a), the wafer 200 having the SiN film formed in island shapes on the surface other than the SiN layer is carried into the processing furnace 202d as the fourth process unit, and the SiN film formed in island shapes on the surface other than the SiN layer is etched.

In the processing furnace 202d, etching is performed by adjusting the pressure and the temperature so that a desired pressure and a desired temperature distribution are achieved in the processing chamber 201 d. In this step, only the portions different from those in the above-described processing furnace 202b will be described, and the description of the same portions will be omitted.

D-1: [ etching gas supply step ]

(etching gas supply: step S25)

The valve 344 is opened, and ClF as an etching gas is flowed into the gas supply pipe 340₃A gas. ClF₃The gas is supplied into the processing chamber 201d from the gas supply hole 440a of the nozzle 440 by adjusting the flow rate of the gas by the MFC342, and is exhausted from the exhaust pipe 231. At this time, as shown in fig. 12 (B), ClF is supplied to the wafer 200₃A gas. In parallel with this, the valve 544 is opened, and N flows into the gas supply pipe 540₂And inert gases such as gases. N flowing in the gas supply pipe 540₂Gas flow regulation by MFC542 with ClF₃Gas is supplied thereto togetherThe chamber 201d is exhausted from the exhaust pipe 231.

At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201d is, for example, in the range of 1 to 1000 Pa. ClF controlled by MFC342₃The supply flow rate of the gas is, for example, in the range of 1 to 1000 sccm. N controlled by MFC542₂The supply flow rate of the gas is, for example, in the range of 100 to 10000 sccm. Supplying ClF to wafer 200₃The gas time is, for example, in the range of 1 to 3600 seconds. The temperature of the heater 207 is set to a temperature of 30 to 500 ℃, preferably 30 to 450 ℃, and more preferably 30 to 400 ℃ for example, for the wafer 200.

Then, ClF is supplied from the beginning₃After a predetermined time of gas supply, the valve 344 of the gas supply pipe 340 is closed to stop the ClF supply₃A gas. Thus, the island-shaped SiN film formed slightly on the oxide film is etched and removed.

D-2: [ purging step ]

(residual gas removal: step S26)

Then, the ClF supply is stopped₃After the gas is exhausted, a purge process for exhausting the gas in the processing chamber 201d is performed. At this time, the inside of the processing chamber 201d is vacuum-exhausted by the vacuum pump 246 while the APC valve 243 of the exhaust pipe 231 is kept open, and unreacted ClF remaining in the processing chamber 201d is removed₃ClF obtained by etching with gas or SiN film formed on a surface other than the SiN layer₃Gas is exhausted from the process chamber 201 d. At this time, the supply of N into the processing chamber 201d is maintained with the valve 544 being opened₂A gas. N is a radical of₂The gas functions as a purge gas, and as shown in fig. 12 (C), unreacted ClF remaining in the processing chamber 201d can be increased₃ClF obtained by etching with gas or SiN film formed on a surface other than the SiN layer₃Gas and by-products generated by etching are exhausted from the processing chamber 201 d.

(Perform a predetermined number of times: step S27)

By performing the cycle of the above steps S25 and S26 sequentially 1 or more times (predetermined number of times (p times)), the SiN film formed on the surface of the wafer 200 other than the SiN layer is dry etched.

(Perform a predetermined number of times: step S28)

By performing the cycle of the above-described steps S16 to S27 1 or more times (predetermined times (q times)), as shown in fig. 12 (D), the presence of an Si layer and SiO on the surface is suppressed₂The SiN film is selectively grown on the surface of the SiN layer while damaging the surface of the Si layer of the wafer 200 of layers and SiN layers.

(3) Effect according to one embodiment of the present invention

As a result of earnest studies by the inventors, it was found that a Si layer or SiO layer is formed on the surface₂A method of preferentially forming a SiN film or a TiN film (selective growth) on a SiN layer of a wafer such as a layer or a SiN layer. The method comprises the following steps: exposure to ClF before film formation₃An adsorption control agent such as gas, and F molecules are adsorbed on the Si layer or SiO layer by properly controlling the temperature, pressure and time of exposure to the adsorption control agent₂On the layer, thereby selectively growing SiN film, TiN film on the SiN layer easily, and Si layer, SiO film₂Selective growth of layers is difficult. However, if the Si layer is exposed to the adsorption control agent containing F, the surface of the Si layer may be damaged by etching or the like due to F molecules.

In this embodiment, before exposing a wafer having at least a Si layer and a SiN layer on the surface to an adsorption control agent containing F and exposing the wafer, DHF cleaning is performed to supply a halide, thereby removing a natural oxide film on the wafer surface. Then, after the native oxide film is removed, the wafer surface is subjected to APM cleaning before the adsorption control agent is exposed, so that an oxide film is hardly formed on the SiN layer surface and an oxide film is formed on the Si layer surface. In other words, an oxide film is formed on the surface of the Si layer.

The oxide film formed on the surface of the Si layer functions as a protective film for the Si layer, and prevents exposure of ClF as an adsorption control agent to the Si layer during the subsequent modification treatment₃The damage of the Si layer due to etching of the Si layer by F component contained in the gas.

Further, since halogen (F molecule) is adsorbed on the oxide film, it is used as a raw materialSiCl of gas₄The halogen (Cl molecules) contained in the gas and the F molecules on the oxide film are electrically negative ligands, and thus serve as repulsive factors and are not adsorbed on the oxide film having the F molecules adsorbed on the surface. Further, since the inorganic substance has high heat resistance for surface modification, even when film formation is performed at a high temperature of 500 ℃ or higher, the adsorption of F molecules on the oxide film is not lost, and the SiN film can be selectively grown on the surface of the SiN layer.

That is, according to the present embodiment, a thin film can be selectively formed on a substrate while suppressing damage to a film on which the thin film is not formed.

(4) Examples of the experiments

(Experimental example 1)

FIG. 13 (A) to FIG. 13 (C) show the substrate processing apparatus 10 described above, in which the Si layer or SiO layer is formed on the surface₂The wafer of the layer and the SiN layer was subjected to the substrate treatment process described above, and a longitudinal sectional view of the wafer on which the SiN film was selectively grown was shown. In this experimental example, the APM cleaning of step S13 of the substrate processing step was performed at 70 ℃.

As shown in FIG. 13 (B), it was confirmed that a SiN film of about 5nm was selectively grown on the SiN layer. As shown in fig. 13 (C), it was confirmed that the Si layer was not damaged by etching and the SiN film was rarely adhered.

(Experimental example 2)

FIG. 14 (A) to FIG. 14 (C) show the substrate processing apparatus 10 described above, in which the Si layer or SiO layer is formed on the surface₂The wafers of the layer and the SiN layer were not subjected to the APM cleaning in steps S13 to S15 in the substrate processing step described above, and the wafers having the SiN film selectively grown on the SiN layer were shown in longitudinal sectional views. That is, the modification treatment in steps S16 to S18 is performed without forming an oxide film on the surface of the Si layer by chemical action after the DHF cleaning in steps S10 to S12, and a wafer in which an SiN film is selectively grown on the SiN layer is shown in a vertical sectional view.

As shown in fig. 14 (B), the SiN film was selectively grown on the SiN layer. However, as shown in fig. 14 (C), it was confirmed that the Si layer was etched.

(Experimental example 3)

FIG. 14 (D) to FIG. 14 (F) show the substrate processing apparatus 10 described above, in which the Si layer or SiO layer is formed on the surface₂The wafers having the layer and the SiN layer were not subjected to DHF cleaning in steps S10 to S12 in the substrate processing step described above, and the wafers having the SiN film selectively grown on the SiN layer were shown in longitudinal sectional views. That is, the longitudinal sectional view of the wafer on which the SiN film is selectively grown on the SiN layer is shown in which the natural oxide film formed on the wafer is not removed, the APM cleaning in steps S13 to S15 is performed, the modification treatment in steps S16 to S18 is performed, and the APM cleaning is performed.

As shown in fig. 14 (E) and 14 (F), it was confirmed that the SiN film was not selectively grown on the SiN layer and on the Si layer. Further, as shown in fig. 14 (F), it was confirmed that the Si layer was not etched. That is, although etching can be prevented by leaving a natural oxide film on the Si layer, selective growth on the SiN layer becomes impossible. This is considered to be because the SiN layer surface is oxidized by ashing treatment or the like in patterning, and the film formation is suppressed.

That is, DHF cleaning is effective when a selective growth of a SiN film is preferable on a SiN layer, but it is confirmed that etching on a Si layer is promoted. However, it was confirmed that etching was suppressed by the subsequent APM cleaning.

(Experimental example 4)

Next, based on fig. 15 (a), how different the SiN film thicknesses are formed in the following cases in the substrate processing step described above using the substrate processing apparatus 10 described above will be described: as comparative example 1, in the case where the above-described DHF cleaning and APM cleaning were not performed on the SiN layer immediately after the film formation, the SiN film was selectively grown; as comparative example 2, in the case where the DHF cleaning and the APM cleaning were not performed on the SiN layer after a lapse of time after the film formation and the SiN film was selectively grown; as comparative example 3, in the case where only DHF cleaning (no APM cleaning) was performed on the SiN layer after a lapse of time from the film formation to selectively grow the SiN film; and as the present example, the case where the substrate processing step (DHF cleaning and APM cleaning) was performed on the SiN layer to selectively grow the SiN film.

As shown in comparative examples 1 and 2 in fig. 15 (a), it was confirmed that the thickness of the selectively grown SiN film was thinner in the case where a certain period of time had elapsed after the film formation than in the case where the SiN film was formed immediately after the film formation. This is considered to be because a natural oxide film is formed on the SiN layer over a certain period of time after the film formation, and this natural oxide film makes it difficult to perform selective growth of the SiN film. As shown in comparative examples 2 and 3, it was confirmed that the thickness of the selectively grown SiN film can be increased by DHF cleaning even after a lapse of time after the film formation. This is considered to be because the native oxide film was removed by DHF cleaning. Further, as shown in comparative example 1, it was confirmed that the SiN film was selectively grown on the SiN layer immediately after the film formation without DHF cleaning. Further, as shown in comparative example 3 and this example, it was confirmed that the film thickness of the SiN film selectively grown on the SiN layer hardly changed even if the APM cleaning was performed after the DHF cleaning. That is, it is considered that the oxidation state of the surface of the SiN layer as the base film becomes a factor for inhibiting the selective growth of the SiN film, and the APM cleaning is not a factor for inhibiting the selective growth.

(Experimental example 5)

Next, based on fig. 15 (B), how different the SiN film thicknesses are formed in the following cases in the substrate processing step described above using the substrate processing apparatus 10 described above will be described: as comparative example 1, in the case where the above-described DHF cleaning and APM cleaning were not performed on the Si layer and the SiN film was selectively grown; as comparative example 2, in the case where only DHF cleaning (no APM cleaning) was performed on the Si layer and a SiN film was selectively grown; as in this example, the substrate treatment process (DHF cleaning and APM cleaning) was performed on the Si layer to selectively grow the SiN film.

As shown in comparative examples 1 and 2 of fig. 15 (B), it was confirmed that the thickness of the SiN film selectively grown on the Si layer becomes thin if DHF cleaning is not performed. This is considered to be because a natural oxide film of about 1.5nm adheres to the Si layer not subjected to DHF cleaning, and this natural oxide film inhibits the selective growth of the SiN film. On the other hand, the DHF cleaning removes the natural oxide film, and the adsorption of the reformed gas that suppresses the subsequent adsorption of the raw material gas is reduced. That is, the SiN film is formed on the Si layer by removing the natural oxide film, and selective growth on the SiN layer becomes impossible. Further, as shown in the present example, even after DHF cleaning is performed to remove the natural oxide film, the oxide film is formed on the Si layer by chemical action by APM cleaning, and thus selective growth of the SiN film can be suppressed as compared with comparative example 2 in which only DHF cleaning is performed.

That is, as shown in the substrate processing step, it was confirmed that the selective growth of the SiN film on the SiN layer and the selective growth of the SiN film on the Si layer were suppressed by performing the APM cleaning after the DHF cleaning.

(5) Other embodiments

In the above embodiment, the cluster-type substrate processing apparatus 10 including the processing furnace 202a having the first gas supply system and the second gas supply system to perform the cleaning process, the processing furnace 202b having the third gas supply system to perform the reforming process, the processing furnace 202c having the fourth gas supply system to perform the film formation process, and the processing furnace 202d having the fifth gas supply system to perform the etching process has been described, but the present invention is not limited to this configuration. The same applies to a substrate processing apparatus having a processing furnace 202a for performing a cleaning process and a substrate processing apparatus 300 having third to fifth gas supply systems in the same processing furnace 202e (processing chamber 201e) as shown in fig. 16 and 17, in which a reforming process, a film formation process, and an etching process are performed in the same processing furnace 202a (processing chamber 201 e). That is, the same can be applied to a configuration in which the substrate processing is performed in situ.

In the above embodiment, the description has been given of the structure in which the processing furnace 202a is a single-wafer type processing furnace, but the present invention is not limited to this case, and can be similarly applied to the structure in which the processing furnace is a batch type processing furnace.

Further, the structures of the processing furnaces 202b to 202d using batch-type processing furnaces have been described, but the present invention is not limited to this, and can be similarly applied to structures using single-wafer-type processing furnaces.

The present invention can be similarly applied to a configuration in which all of the above-described processes are performed in the same processing furnace using a substrate processing apparatus having the first to fifth gas supply systems in the same processing furnace. In this case, the first gas supply system and the second gas supply system perform dry cleaning using gas without performing wet cleaning using the chemical solution, the rinse solution, or the like.

In the above embodiment, the case where DHF is used as the gas for removing the natural oxide film has been described, but the present invention is not limited to this case. The present invention can be similarly applied to the case where other chemical liquids such as hydrogen fluoride (hydrofluoric acid, HF) and isopropyl ether (IPE) are used as the gas for removing the natural oxide film. Water (H) mixed with these may also be used₂O), alcohol, amine fluoride (NH)₄F) And the like.

In the above embodiment, ammonia (NH) is used as the oxidizing agent₃) And hydrogen peroxide water (H)₂O₂) The case of the mixed solution (SC1 liquid) of (a), however, the present invention is not limited to this case. The present invention can be similarly applied to the case where the oxidizing agent is at least 1 type of oxidizing agent selected from the group consisting of ammonia, hydrogen peroxide water, hydrogen peroxide gas (HCA: Hyper Cure Anneal), a mixed gas of an oxygen active species and a hydrogen active species, and oxygen.

In the above embodiment, ClF is used as the modifying gas₃The case of gas is illustrated, but the present invention is not limited to this case. Tungsten hexafluoride (WF) is used as the modifying gas₆) Gas, nitrogen trifluoride (NF)₃) Gas, Hydrogen Fluoride (HF) gas, fluorine (F)₂) The present invention can be similarly applied to other gases such as gas.

In the above embodiment, as the source gas for selective growth, SiCl as the Si source gas is used₄The case of gas is illustrated, but the present invention is not limited to this case. Titanium tetrachloride (TiCl) is used as the raw material gas₄)、Aluminium tetrachloride (AlCl)₄) Zirconium tetrachloride (ZrCl)₄) Hafnium tetrachloride (HfCl)₄) Tantalum pentachloride (TaCl)₅) Tungsten pentachloride (WCl)₅) Molybdenum pentachloride (MoCl)₅) Tungsten hexachloride (WCl)₆) The present invention can be similarly applied to other gases such as metal source gases such as gas.

In addition, ClF was used as the modifying gas₃When the gas is used, silicon tetrachloride (SiCl) which is a raw material gas used in selective growth is used₄) And NH₃The gas allows selective growth of the SiN film at a high temperature of about 550 ℃. In addition, titanium tetrachloride (TiCl) as a raw material gas used in the selective growth is used₄) And NH₃The gas can selectively grow TiN film at a low temperature of about 300 ℃.

In the above embodiment, ClF is used as the etching gas₃The case of gas is illustrated, but the present invention is not limited to this case. As etching gas, NF is used₃、CF₄、CHF₃、CH₂F、ClF、F₂The present invention is also applicable to other gases such as HF.

In the above embodiment, the case where the reforming treatment and the etching treatment are performed in different treatment furnaces has been described, but the reforming treatment and the etching treatment may be performed in the same treatment furnace or the etching treatment may be performed as the reforming treatment. In these cases, the temperature in the reforming treatment is about 100 ℃, and the temperature in the etching treatment is about 150 ℃, and the like, under the respective processing conditions in the respective processing steps.

While various exemplary embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can be applied by being appropriately combined.

Description of the symbols

10. 300, and (2) 300: a substrate processing apparatus is provided with a substrate processing chamber,

121: a controller for controlling the operation of the electronic device,

200: a wafer (substrate),

202a, 202b,202 c, 202d, 202 e: and (4) treating the furnace.