WO2024070858A1

WO2024070858A1 - Substrate processing method

Info

Publication number: WO2024070858A1
Application number: PCT/JP2023/034146
Authority: WO
Inventors: 暁志布瀬; 一也戸田
Original assignee: 東京エレクトロン株式会社
Priority date: 2022-09-27
Filing date: 2023-09-20
Publication date: 2024-04-04
Also published as: JP2024048047A

Abstract

Provided is a substrate processing method in which, for a substrate comprising a first surface including a metallic material and a second surface including a dielectric material, a silicon dioxide film is selectively formed on the second surface relative to the first surface.　The substrate processing method comprises: a step for preparing a first surface including a metallic material and a second surface including a dielectric material containing oxygen; a step for exposing the substrate to a boron-containing substance to selectively form a boron-containing film on the second surface relative to the first surface; and a step for exposing the substrate to a silanol gas to form a silicon dioxide film on the second surface on which the boron-containing film was formed.

Description

Substrate processing method

This disclosure relates to a substrate processing method.

Patent Document 1 discloses a substrate processing method, comprising the steps of: disposing substrates on a plurality of substrate supports in a processing chamber, the processing chamber including a processing space defined around a rotation axis in the processing chamber, each substrate including a first surface and a second surface; rotating the plurality of substrate supports around the rotation axis; exposing the substrate to a reaction gas including a metal-containing catalyst; exposing the substrate to a cleaning gas that removes an oxide layer from the second surface together with the metal-containing catalyst on the oxide layer; exposing the substrate to a deposition gas including a silanol gas that selectively deposits an initial SiO ₂ film on the metal-containing catalyst layer on the first surface for a certain period of time, the initial SiO ₂ film forming a raised feature adjacent to the second surface; exposing the substrate to the reaction gas using the metal-containing catalyst layer to selectively cover the raised feature of the initial SiO ₂ film but not the second surface; and depositing additional SiO 2 on the metal-containing catalyst on the raised feature of the initial SiO ₂ film for a certain period of time. and exposing the substrate to a deposition gas containing the silanol gas that selectively deposits the silanol-containing _{SiO 2} film.

JP 2019-96881 A

The present disclosure provides a substrate processing method for forming a silicon oxide film selectively on a substrate having a first surface including a metal material and a second surface including a dielectric material relative to the first surface.

A substrate processing method according to one aspect of the present disclosure includes the steps of preparing a substrate having a first surface including a metallic material and a second surface including an oxygen-containing dielectric material, exposing the substrate to a boron-containing substance to selectively form a boron-containing film on the second surface relative to the first surface, and exposing the substrate to a silanol gas to form a silicon oxide film on the second surface on which the boron-containing film has been formed.

According to the present disclosure, a substrate processing method can be provided for a substrate having a first surface including a metal material and a second surface including a dielectric material, in which a silicon oxide film is selectively formed on the second surface relative to the first surface.

1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to an embodiment. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to an embodiment. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to an embodiment. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to an embodiment. 1 is an example of a flowchart illustrating a method for forming a silicon oxide film according to an embodiment. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to a reference example. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to a reference example. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to a reference example. 1A to 1C are schematic cross-sectional views illustrating a configuration of a substrate in a method for forming a silicon oxide film according to a reference example. 1 is an example of a flowchart showing a method for forming a silicon oxide film according to a reference example. 1 is an example of a graph showing the results of an XPS analysis in the case where a boron-containing film is formed on a silicon oxide. 1 is an example of a graph showing the results of an XPS analysis in the case where a boron-containing film is formed on ruthenium. 1 is an example of a graph showing the results of an XPS analysis in the case where a silicon oxide film is formed on a boron-containing film. 11 is an example of a flowchart illustrating another method for forming a silicon oxide film according to an embodiment.

Below, non-limiting exemplary embodiments of the present disclosure will be described with reference to the attached drawings. In all of the attached drawings, the same or corresponding members or parts are designated by the same or corresponding reference symbols, and duplicate descriptions will be omitted.

[Method of forming silicon oxide film according to one embodiment]
A method for forming a silicon oxide film according to an embodiment will be described with reference to Figures 1A to 1D and 2. Figures 1A to 1D are exemplary cross-sectional schematic views illustrating the configuration of a substrate W in the method for forming a silicon oxide film according to an embodiment. Figure 2 is an exemplary flowchart illustrating the method for forming a silicon oxide film according to an embodiment.

In step S11, a process for preparing the substrate W is performed. Here, the substrate W is transported into a processing vessel of the substrate processing apparatus, and the substrate W is placed on a mounting table in the processing vessel.

FIG. 1A is an example of a schematic cross-sectional view illustrating the configuration of a substrate W to be prepared. The substrate W has a metal layer (first metal film) 110 formed of a metal material, and a dielectric layer (first dielectric film, first insulator film) 120 formed of a dielectric material. The surface (top surface) of the substrate W has a first surface S1 containing a metal material, and a second surface S2 containing a dielectric material. A metal oxide layer (natural oxide film) 111 may also be formed on the surface of the metal layer 110.

Here, the metal material of the metal layer 110 may be, for example, any one of Ru, Cu, Co, W, etc. The dielectric material of the dielectric layer 120 may be, for example, silicon oxide. The silicon oxide contains at least silicon (Si) and oxygen (O). The silicon oxide is, for example, SiO _2. The silicon oxide may contain other atoms (for example, carbon (C), nitrogen (N), etc.) in addition to silicon (Si) and oxygen (O). The silicon oxide may be, for example, any one of SiOC, SiON, SiOCN, etc.

In step S12, the substrate W is exposed to a cleaning gas to clean the surface of the substrate W. Here, the cleaning gas is supplied into a processing vessel that contains the substrate W to clean the surface of the substrate W in the processing vessel.

A reducing gas that reduces the metal oxide layer 111 may be used as the cleaning gas. This reduces the metal oxide layer 111 formed on the surface (first surface S1) of the metal layer 110, and removes the metal oxide layer 111. Also, an etching gas that etches the metal oxide layer 111 may be used as the cleaning gas. This removes the metal oxide layer 111 formed on the surface (first surface S1) of the metal layer 110. Specifically, the cleaning gas may be, for example, any one of hydrogen gas, water gas, carboxylic acid gas, fluorine-containing organic gas, etc., or a combination thereof. Also, the process of cleaning the surface of the substrate W may be a process of exposing the substrate W to a plasma of a cleaning gas. In this case, the cleaning gas may be any one of hydrogen gas, water gas, carboxylic acid gas, fluorine-containing organic gas, etc., or a combination of these gases.

FIG. 1B is an example of a schematic cross-sectional view illustrating the configuration of the substrate W after the process of cleaning the surface of the substrate W. By removing the metal oxide layer 111, the first surface S1 is formed of the metal material of the metal layer 110. Furthermore, the second surface S2 is formed of the dielectric material (silicon oxide) of the dielectric layer 120.

In step S13, the substrate W is exposed to a boron-containing substance to form a boron-containing film 130 on the surface of the substrate W.

FIG. 1C is an example of a schematic cross-sectional view illustrating the configuration of the substrate W after the process of forming the boron-containing film 130. Here, since boron (B) has a high tendency to bond with oxygen (O), the boron-containing film 130 is likely to be selectively formed on the surface of a material containing oxygen (O). That is, the boron-containing film 130 is more likely to be formed on the surface (second surface S2) of the dielectric layer 120 containing oxygen (O) than on the surface (first surface S1) of the metal layer 110. In other words, in the process of forming the boron-containing film 130, the boron-containing film 130 is selectively formed on the second surface S2 of the surfaces (first surface S1, second surface S2) of the substrate W relative to the first surface S1. The thickness of the boron-containing film 130 formed on the second surface S2 is defined as the first thickness T1. The thickness (first thickness T1) of the boron-containing film 130 formed on the second surface S2 is formed to be thicker than the thickness of the boron-containing film 130 formed on the first surface S1.

The boron-containing film 130 may be a boron film, a boron oxide film (a film containing at least boron (B) and oxygen (O)), a boron nitride film (a film containing at least boron (B) and nitrogen (N)), or a film containing boron (B) and other atoms.

The boron-containing film 130 may be formed by a PVD (Physical Vapor Deposition) method. That is, a target made of a boron-containing material may be sputtered in a processing vessel, and the substrate W may be exposed to the sputtered particles (boron-containing material) emitted from the target, thereby depositing the sputtered particles on the surface of the substrate W, thereby forming the boron-containing film 130 on the surface of the substrate W. For example, a boron (B) target may be sputtered in a processing vessel to form a boron film (boron-containing film 130) on the surface of the substrate W.

The boron-containing film 130 may be formed by simultaneously supplying a boron precursor gas (a boron-containing substance) and a reactive gas into a processing chamber and using a chemical vapor deposition (CVD) method. In this case, the boron precursor gas may be, for example, any one of TDMAB (Tris-(dimethylamino)borane), TEMAB (Tris-(diethylamino)borane), BCl ₃ , BH ₄ , B ₂ H ₆ , etc. The reactive gas may be, for example, any one of N ₂ , H ₂ , H ₂ O, O _{2 ,} etc.

The boron-containing film 130 may be formed by alternately supplying a boron precursor gas (boron-containing material) and a reactive gas into a processing chamber by an atomic layer deposition (ALD) method. In this case, the boron precursor gas may be, for example, any one of TDMAB (Tris-(dimethylamino)borane), TEMAB (Tris-(diethylamino)borane), BCl ₃ , BH ₄ , B ₂ H ₆ , etc. The reactive gas may be, for example, any one of N ₂ , H ₂ , H ₂ O, O _{2 ,} etc.

In step S14, the substrate W is exposed to silanol gas to form a silicon oxide film 140 on the surface of the substrate W. Here, silanol gas is supplied into a processing vessel that contains the substrate W, and a silicon oxide film (second dielectric film, second insulator film) 140 is formed on the surface of the substrate W in the processing vessel.

As the silanol gas, for example, TPSOL (Tris(tert-pentoxy)silanol), TBSOL (Tris(tert-buthoxy)silanol), etc. can be used.

FIG. 1D is an example of a schematic cross-sectional view illustrating the configuration of the substrate W after the process of forming the silicon oxide film 140. Here, the boron-containing film 130 formed on the substrate W is used as a catalyst for forming the silicon oxide film 140. Alternatively, the boron-containing film 130 formed on the substrate W is used as a reaction accelerator for promoting the formation of the silicon oxide film 140. As shown in step S13 and FIG. 1C, the boron-containing film 130 is selectively formed on the second surface S2 with respect to the first surface S1. Therefore, the silicon oxide film 140 is more likely to be formed on the surface of the boron-containing film 130 (on the second surface S2) than on the surface of the metal layer 110 (the first surface S1). Therefore, as shown in FIG. 1D, in the process of forming the silicon oxide film 140, the silicon oxide film 140 is selectively formed on the second surface S2 on which the boron-containing film 130 is formed with respect to the first surface S1. Furthermore, the thickness of the silicon oxide film 140 formed on the second surface S2 is made thicker than the thickness of the silicon oxide film 140 formed on the first surface S1.

This allows the silicon oxide film 140 to be selectively formed on the second surface S2 relative to the first surface S1. Also, a recess is formed on the substrate W, the sidewall of which is formed of the silicon oxide film 140, and the bottom wall of which is formed of the metal layer 110.

Furthermore, after step S14, a process of embedding a metal film (second metal film) in the recess may be included. This results in the metal layer (first metal film) 110 and the metal film (second metal film) embedded in the recess being formed so as to be electrically conductive.

Furthermore, after step S14, before the step of embedding the metal film, a step of removing the boron-containing film 130 and silicon oxide film 140 formed slightly on the first surface S1 by etching or the like may be performed. Here, the film thickness of the boron-containing film 130 and silicon oxide film 140 formed on the first surface S1 is sufficiently thin compared with the film thickness of the boron-containing film 130 and silicon oxide film 140 formed on the second surface S2. Therefore, even if the substrate W is subjected to an etching process to remove the boron-containing film 130 and silicon oxide film 140 formed on the first surface S1, the boron-containing film 130 and silicon oxide film 140 can be left on the second surface S2. In addition, the step of removing the boron-containing film 130 and silicon oxide film 140 formed on the first surface S1 can use, as an etching gas, any of oxygen gas, water gas, fluorine-containing organic gas, etc. Furthermore, the step of removing the boron-containing film 130 and the silicon oxide film 140 formed on the first surface S1 may be a step of exposing the substrate W to plasma.

The process of cleaning the surface of the substrate W (step S12), the process of forming the boron-containing film 130 (step S13), and the process of forming the silicon oxide film 140 (step S14) may be performed in the same processing vessel, in different processing vessels, or in multiple processing vessels connected via a vacuum transfer chamber.

[Method of forming silicon oxide film according to a reference example]
Here, a method for forming a silicon oxide film according to a reference example will be described with reference to Figures 3A to 3D and 4. Figures 3A to 3D are examples of schematic cross-sectional views illustrating the configuration of a substrate W in the method for forming a silicon oxide film according to a reference example. Figure 4 is an example of a flowchart showing the method for forming a silicon oxide film according to a reference example.

In step S21, a process for preparing the substrate W is performed. Here, the substrate W is transported into a processing vessel of the substrate processing apparatus, and the substrate W is placed on a mounting table in the processing vessel.

FIG. 2(a) is an example of a schematic cross-sectional view illustrating the configuration of the substrate W to be prepared. The substrate W has a metal layer 110 formed of a metal material, and a dielectric layer 120 formed of a dielectric material. The surface (top surface) of the substrate W has a first surface S1 containing a metal material, and a second surface S2 containing a dielectric material. A metal oxide layer (natural oxide film) may be formed on the surface of the metal layer 110. The metal material of the metal layer 110 and the dielectric material of the dielectric layer 120 are the same as the metal material and dielectric material described using FIGS. 1A to 1D and 2.

In step S22, a process is performed to form a self-assembled monolayer (SAM) 150 on the surface of the substrate W. Here, an organic compound is supplied into a processing vessel that contains the substrate W, and a self-assembled monolayer 150 is formed on the surface of the substrate W in the processing vessel.

FIG. 4(b) is an example of a schematic cross-sectional view illustrating the structure of the substrate W after the process of forming the self-assembled monolayer 150. Here, the organic compound has a main chain (chain portion) and a functional group formed at one end of the main chain. The main chain is formed by a series of carbons (C). The main chain is formed, for example, of an alkyl chain. The functional group is a functional group that selectively adsorbs (bonds) to the metal layer 110. The functional group includes, for example, at least one of thiol, carboxylic acid, sulfonic acid, phosphoric acid, olefin, etc. The functional group of the organic compound is adsorbed to the surface of the metal layer 110, and the organic compound is oriented due to the interaction between the organic compounds, thereby forming the self-assembled monolayer 150. As a result, as shown in FIG. 4(b), the self-assembled monolayer 150 is formed on the surface (first surface S1) of the metal layer 110. On the other hand, the functional group of the organic compound is suppressed from adsorbing to the dielectric layer 120. As a result, in the process of forming the self-assembled monolayer 150, the self-assembled monolayer 150 is selectively formed on the first surface S1 relative to the second surface S2.

In step S23, a process of forming a silicon oxide film 140 on the surface of the substrate W is performed. Here, silanol gas and a reactive gas are supplied into a processing vessel that contains the substrate W, and a silicon oxide film 140 is formed on the surface of the substrate W in the processing vessel. As the silanol gas, for example, TPSOL (Tris(tert-pentoxy)silanol) can be used. As the reactive gas, TMA (trimethylaluminum) can be used.

FIG. 4(c) is an example of a schematic cross-sectional view illustrating the structure of the substrate W after the process of forming the silicon oxide film 140. Here, TMA used as a catalyst is selectively adsorbed to the dielectric layer 120 relative to the surface of the self-assembled monolayer 150. Then, TPSOL is bonded to the TMA adsorbed to the surface (second surface S2) of the dielectric layer 120 to form the silicon oxide film 140. Therefore, as shown in FIG. 4(c), in the process of forming the silicon oxide film 140, the silicon oxide film 140 is selectively formed on the second surface S2 relative to the surface of the self-assembled monolayer 150. In addition, the thickness of the silicon oxide film 140 formed on the second surface S2 is formed to be thicker than the thickness of the silicon oxide film 140 formed on the surface of the self-assembled monolayer 150.

In step S24, a process of removing the self-assembled monolayer 150 is performed. Here, the self-assembled monolayer 150 formed on the first surface S1 and the silicon oxide film 140 formed on the self-assembled monolayer 150 are removed.

FIG. 4(d) is an example of a schematic cross-sectional view illustrating the structure of the substrate W after the process of removing the self-assembled monolayer 150. This allows the silicon oxide film 140 to be selectively formed on the second surface S2 relative to the first surface S1. In addition, the substrate W has a recess whose sidewalls are formed of the silicon oxide film 140 and whose bottom wall is formed of the metal layer 110.

[Comparison between one embodiment and reference example]
Thus, in the formation method according to the reference example shown in Figures 3A to 3D and Figure 4, in step S22, self-assembled monolayer 150 that inhibits the formation of silicon oxide film 140 is formed on first surface S1, and then in step S23, silicon oxide film 140 is selectively formed on second surface S2 relative to first surface S1.

In contrast, in the formation method according to one embodiment shown in Figures 1A to 1D and 2, a boron-containing film 130 that promotes the formation of a silicon oxide film 140 on the second surface S2 is formed in step S13, and then a silicon oxide film 140 is selectively formed on the second surface S2 relative to the first surface S1 in step S14. In this way, the formation method according to one embodiment can selectively form a silicon oxide film 140 on the second surface S2 relative to the first surface S1 by a process different from that of the formation method according to the reference example.

In addition, in the formation method according to one embodiment shown in Figures 1A to 1D and 2, before forming the boron-containing film 130 shown in step S13, the metal oxide layer (native oxide film) 111 is removed by cleaning the surface of the substrate W in step S12. This can further suppress the formation of the boron-containing film 130 on the first surface S1. In addition, by suppressing the formation of the boron-containing film 130 on the first surface S1, it can further suppress the formation of the silicon oxide film 140 on the first surface S1.

[Selectivity of boron-containing film 130]
Next, the selectivity of the boron-containing film 130 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is an example of a graph showing the results of XPS analysis when a boron-containing film is formed on a silicon oxide as a dielectric layer. Fig. 6 is an example of a graph showing the results of XPS analysis when a boron-containing film is formed on a ruthenium as a metal layer.

In Fig. 5, silicon (SiO ₂ ) having a natural oxide film formed on its surface is used as an underlayer, and a boron film is formed on the underlayer by PVD. That is, Fig. 5 corresponds to the case where a boron-containing film 130 is formed on the second surface S2. Also, in Fig. 6, ruthenium (Ru) is used as the underlayer, and a boron film is formed on the underlayer by PVD. That is, Fig. 6 corresponds to the case where a boron-containing film 130 is formed on the first surface S1.

Each of the substrates W thus formed was analyzed by X-ray photoelectron spectroscopy (XPS). In Figs. 5 and 6, the horizontal axis indicates the sputtering time. In other words, the horizontal axis corresponds to the depth from the substrate surface. The vertical axis indicates the composition ratio (%). Note that in Fig. 5, only silicon (Si) in the dielectric layer 120 and boron (B) in the boron-containing film 130 are shown in the graph, and other atoms are not shown in the graph. Also, in Fig. 6, only ruthenium (Ru) in the metal layer 110 and boron (B) in the boron-containing film 130 are shown in the graph, and other atoms are not shown in the graph.

Here, a boron-containing film 130 is defined as one having a composition ratio (%) of boron (B) of 30% or more, and the thickness of the boron-containing film 130 (B-containing film thickness) is indicated by an arrow in the graphs of Figures 5 and 6. A comparison of Figures 5 and 6 shows that the boron-containing film 130 is formed thicker on the silicon oxide film (see Figure 5) than on the ruthenium film (see Figure 6). In other words, the boron-containing film 130 is selectively formed on the second surface S2 relative to the first surface S1.

[Catalytic properties of boron-containing film 130]
Next, the catalytic properties of the boron-containing film 130 will be described with reference to Fig. 7. Fig. 7 is an example of a graph showing the results of an XPS analysis in the case where a silicon oxide film 140 is formed on a boron-containing film.

Copper (Cu) was used as an underlayer, and boron films (boron-containing films 130) with thicknesses of 5 nm, 10 nm, and 20 nm were formed on the underlayer by the PVD method. Silicon oxide films 140 were then formed on the boron films with different thicknesses.

Each of the substrates W thus formed was analyzed by X-ray photoelectron spectroscopy (XPS). In FIG. 7, the horizontal axis indicates the binding energy, and the vertical axis indicates the intensity of the detection signal. FIG. 7 also shows the results near the peak corresponding to silicon (Si). The area of the peak corresponds to the film thickness of the silicon oxide film 140, and a wider area of the peak (higher peak) indicates a thicker film thickness of the silicon oxide film 140.

As shown in FIG. 7, it was confirmed that a silicon oxide film 140 was formed on the boron-containing film 130 when the film thickness (first film thickness T1) of the boron film (boron-containing film 130) was in the range of 5 nm to 20 nm.

Furthermore, as shown in FIG. 7, it was confirmed that the thickness of the silicon oxide film 140 is significantly improved by setting the thickness of the boron film to 20 nm, compared to when the thickness is 5 nm and 10 nm. In other words, it was confirmed that the catalytic effect of the boron-containing film 130 is significantly improved by setting the thickness of the boron film to 20 nm or more.

[Another method for forming a silicon oxide film according to an embodiment]
Next, another method for forming a silicon oxide film according to an embodiment will be described with reference to Fig. 8. Fig. 8 is an example of a flow chart showing another method for forming a silicon oxide film according to an embodiment.

In step S31, a process of preparing a substrate W is performed in the same manner as in step S11. Here, the substrate W is transported into a processing vessel of the substrate processing apparatus, and the substrate W is placed on a mounting table in the processing vessel. The substrate W to be prepared has a metal layer (first metal film) 110 formed of a metal material and a dielectric layer (first dielectric film, first insulator film) 120 formed of a dielectric material, similar to the substrate W shown in FIG. 1A. The surface (upper surface) of the substrate W has a first surface S1 containing a metal material and a second surface S2 containing a dielectric material. A metal oxide layer (natural oxide film) 111 may be formed on the surface of the metal layer 110. The metal material of the metal layer 110 and the dielectric material of the dielectric layer 120 are the same as the metal material and the dielectric material described using FIGS. 1A to 1D and 2.

In step S32, similar to step S12, the substrate W is exposed to a cleaning gas to clean the surface of the substrate W. Here, cleaning gas is supplied into a processing vessel that contains the substrate W to clean the surface of the substrate W in the processing vessel. After the process of cleaning the surface of the substrate W, the metal oxide layer 111 is removed from the substrate W, similar to the substrate W shown in FIG. 1B. As a result, the first surface S1 is formed of the metal material of the metal layer 110. The second surface S2 is formed of the dielectric material (silicon oxide film) of the dielectric layer 120.

In step S33, similar to step S13, the substrate W is exposed to a boron-containing substance to form a boron-containing film 130 on the surface of the substrate W. After the step of forming the boron-containing film 130, the substrate W has the boron-containing film 130 selectively formed on the second surface S2 relative to the first surface S1, similar to the substrate W shown in FIG. 1C.

In step S34, a process of removing the boron-containing film 130 on the first surface S1 is performed. Here, the thickness of the boron-containing film 130 formed on the first surface S1 is sufficiently thin compared to the thickness of the boron-containing film 130 formed on the second surface S2. Therefore, even if the substrate W is subjected to an etching process and the boron-containing film 130 formed on the first surface S1 is removed, the boron-containing film 130 can be left on the second surface S2. Note that the process of removing the boron-containing film 130 formed on the first surface S1 can use, as an etching gas, any of oxygen gas, water gas, fluorine-containing organic gas, etc. Also, the process of removing the boron-containing film 130 formed on the first surface S1 may be a process of exposing the substrate W to plasma.

In step S35, similar to step S14, the substrate W is exposed to silanol gas to form a silicon oxide film 140 on the surface of the substrate W. Here, silanol gas is supplied into a processing vessel that contains the substrate W, and a silicon oxide film (second dielectric film, second insulator film) 140 is formed on the surface of the substrate W in the processing vessel. After the process of forming the silicon oxide film 140, the substrate W is similar to the substrate W shown in FIG. 1D, in that the silicon oxide film 140 is selectively formed on the second surface S2 on which the boron-containing film 130 is formed, relative to the first surface S1.

In step S36, the process from step S33 to step S35 constitutes one cycle, and it is determined whether the number of cycles has reached a predetermined number of repetitions. If the number of cycles has not reached the predetermined number of repetitions (S36: NO), the process returns to step S33, and the process from step S33 to step S35 is repeated. That is, the cycle including the process from step S33 to step S35 is repeated. If the number of cycles has reached the predetermined number of repetitions (S36: YES), the process of forming the silicon oxide film 140 is terminated.

In addition, the thickness of the silicon oxide film 140 formed on the second surface S2 can be increased. This allows the aspect ratio of the recess to be increased.

Furthermore, after the formation process of the silicon oxide film 140 is completed (S36, YES), a process of embedding a metal film (second metal film) in the recess may be included. This results in the metal layer (first metal film) 110 and the metal film (second metal film) embedded in the recess being formed so as to be electrically conductive.

The process of cleaning the surface of the substrate W (step S32), the process of forming the boron-containing film 130 (step S33), the process of removing the boron-containing film 130 on the first surface S1 (step S34), and the process of forming the silicon oxide film 140 (step S35) may be performed in the same processing vessel, in different processing vessels, or in multiple processing vessels connected via a vacuum transfer chamber.

The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

This application claims priority based on Japanese Patent Application No. 2022-153879, filed on September 27, 2022, and the entire contents of these Japanese patent applications are incorporated by reference into this application.

110 Metal layer 111 Metal oxide layer 120 Dielectric layer 130 Boron-containing film 140 Silicon oxide film 150 Self-assembled monolayer S1 First surface S2 Second surface

Claims

Providing a substrate having a first surface comprising a metallic material and a second surface comprising an oxygen-containing dielectric material;
exposing the substrate to a boron-containing material to selectively form a boron-containing film on the second surface relative to the first surface;
and exposing the substrate to a silanol gas to form a silicon oxide film on the second surface on which the boron-containing film is formed.
A method for processing a substrate.
In the step of selectively forming a boron-containing film on the second surface, the thickness of the boron-containing film formed on the second surface is within a range of 5 mm to 20 mm.
The method for processing a substrate according to claim 1 .
The dielectric material is silicon oxide.
The substrate processing method according to claim 2 .
4. The substrate processing method according to claim 3, wherein the metallic material is any one of Ru, Cu, Co, and W.
the boron-containing film is formed by sputtering a target formed of the boron-containing material in a processing vessel that accommodates the substrate;
The substrate processing method according to claim 1 .
The boron-containing film is formed by supplying a boron precursor, which is the boron-containing substance, and a reaction gas to a processing vessel that accommodates the substrate.
The substrate processing method according to claim 1 .
The boron-containing film is formed by alternately supplying a boron precursor, which is the boron-containing substance, and a reaction gas into a processing vessel that accommodates the substrate.
The substrate processing method according to claim 1 .
The boron precursor is TDMAB, TEMAB, BCl3 , BH4 , or B2H6 ;
The substrate processing method according to claim 6 .
The reactive gas is N2 , H2 , H2O , O2 , or a combination thereof;
The substrate processing method according to claim 8 .
The silanol gas is either TPSOL or TBSOL.
The substrate processing method according to claim 1 .
and exposing the substrate to a cleaning gas to clean a surface of the substrate prior to forming the boron-containing film.
The substrate processing method according to claim 1 .
The cleaning gas is any one of hydrogen gas, water gas, and fluorine-containing organic gas, or a combination thereof.
The method of claim 11.
The cleaning step includes exposing the substrate to a plasma of any one of hydrogen gas, water gas, and fluorine-containing organic gas, or a combination thereof;
The method of claim 11.
The method further includes removing the boron-containing film formed on the first surface after the step of forming the boron-containing film and before the step of forming the silicon oxide film.
The substrate processing method according to claim 1 .
repeating a cycle including the steps of forming the boron-containing film, removing the boron-containing film formed on the first surface, and forming the silicon oxide film;
The method of claim 14.
The method further includes removing the boron-containing film and the silicon oxide film formed on the first surface after the step of forming the silicon oxide film.
The substrate processing method according to claim 1 .