Substrate processing method and substrate processing apparatus

Abstract

To provide a substrate processing method and a substrate processing device, capable of selectively forming a self-assembled monolayer improved in a function as a protective film by achieving a uniformed and improved film density thereby to suppress or reduce the occurrence of film defects.SOLUTION: The present invention relates to a substrate processing method for processing a substrate having, on a surface, a metal film formed region in which a metal film 1 is formed and a metal film non-formed region in which the metal film 1 is not formed. The substrate processing method includes: an artificial oxide film formation step for forming an artificial oxide film 4 by oxidizing, under atmospheric pressure, a surface of the metal film 1, the surface being not natively oxidized; and a self-assembled monolayer formation step for forming a self-assembled monolayer 6 on the artificial oxide film 4 by at least bringing a processing liquid into contact with the surface of the substrate, the processing liquid containing a material for forming the self-assembled monolayer 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus capable of forming a self-assembled monolayer (SAM) on a substrate with high film density and suppressing or reducing film defects. [Background technology]

[0002] In the manufacturing of semiconductor devices, photolithography is widely used as a technique for selectively forming films on specific surface areas of a substrate. For example, after forming the underlying wiring, an insulating film is deposited, and a dual damascene structure with trenches and via holes is formed by photolithography and etching. Conductive films such as Cu are then embedded in the trenches and via holes to form the wiring.

[0003] However, with the increasing miniaturization of semiconductor devices in recent years, photolithography technology is sometimes insufficient in terms of alignment accuracy. Therefore, there is a need for alternative methods to photolithography that can selectively form films on specific areas of the substrate surface with high precision.

[0004] For example, Patent Document 1 discloses a film deposition method that forms a self-assembled monolayer on the surface of a substrate region where film formation is not desired, and selectively forms a film in a substrate region where SAM has not been formed. According to this film deposition method, by using a solvent with an optimal dielectric constant, more specifically a mixed solvent consisting of propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA), as the processing solution for forming SAM, it is possible to suppress a reduction in the coverage rate of SAM and prevent a decrease in the selectivity of the processing solution for metal films.

[0005] For example, if the substrate is made of copper, the substrate surface contains a mixture of exposed Cu and native oxide films consisting of copper(I) oxide (CuO film) and copper(II) oxide (CuO film). Therefore, it is difficult for molecules that form SAM to adsorb uniformly and at high density onto the substrate surface. As a result, film defects occur in areas where molecules that form SAM could not be adsorbed, leading to the formation of a SAM with low film density and non-uniformity. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent No. 10,867,850 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a substrate processing method and a substrate processing apparatus that enable the selective deposition of a self-assembled monolayer film with improved protective function by uniformly increasing film density and suppressing or reducing the occurrence of film defects. [Means for solving the problem]

[0008] The substrate processing method according to the present invention is a substrate processing method for processing a substrate having a metal film-forming region on its surface and a metal film-non-forming region on its surface where the metal film is not formed, in order to solve the above-mentioned problems, and is characterized by comprising: an artificial oxide film formation step of oxidizing the surface of the metal film that has not been naturally oxidized under atmospheric pressure to form an artificial oxide film; and a self-assembled monolayer formation step of forming the self-assembled monolayer on the artificial oxide film by bringing a processing liquid containing a material for forming a self-assembled monolayer into contact with at least the surface of the substrate.

[0009] In metal films whose surfaces are naturally oxidized, for example, when the metal film is a copper film, a mixture of natural oxide films consisting of copper(I) oxide and copper(II) oxide films is formed. Furthermore, since the natural oxide films are not formed uniformly, there are also areas where the metal film is exposed. As a result, the surface state of naturally oxidized metal films is not uniform. However, with the above configuration, by oxidizing the surface of a metal film whose surface is not naturally oxidized to form an artificial oxide film, the surface state can be made uniform compared to a metal film on which such a natural oxide film has formed. This allows molecules that form self-assembled monolayers to be adsorbed on the artificial oxide film more uniformly and at a higher density compared to when molecules that form a natural oxide film are adsorbed on a metal film on which a natural oxide film has formed. As a result, with the above configuration, a self-assembled monolayer can be formed with a high film density and with film defects suppressed or reduced.

[0010] In the above configuration, the artificial oxide film formation step may be a step of irradiating the surface of the metal film, whose surface has not been naturally oxidized, with ultraviolet light.

[0011] The artificial oxide film formation step may also be a step of bringing an oxidizing treatment solution into contact with the surface of the metal film whose surface has not been naturally oxidized.

[0012] In the above configuration, the artificial oxide film formation step is preferably a step in which the surface of the metal film that has not been naturally oxidized is oxidized to form the artificial oxide film, thereby making the isoelectric point of the metal film formation region more uniform and higher in the plane than before the artificial oxide film was formed. By making the isoelectric point of the metal film formation region uniform and raising it through the formation of the artificial oxide film, if, for example, a compound having an anionic functional group is used as the material for forming the self-assembled monolayer, the compound can be adsorbed uniformly and at high density onto the artificial oxide film by an acid-base reaction between the artificial oxide film surface and the anionic functional group. As a result, a self-assembled monolayer with a more uniform and higher film density and suppressed or reduced film defects can be formed.

[0013] Furthermore, in the above configuration, it is preferable to include a native oxide film removal step before the artificial oxide film formation step, in which the native oxide film formed on the surface of the metal film is removed. For example, when a metal film comes into contact with air at room temperature, the metal on the surface reacts with oxygen in the air, and a native oxide film is formed on the surface of the metal film. However, as in the above configuration, by removing this native oxide film before the artificial oxide film formation step, a substrate with the metal film exposed on the surface can be prepared.

[0014] Furthermore, in the above configuration, the native oxide film removal step may be a step of removing the native oxide film by bringing the native oxide film into contact with an acidic solution.

[0015] Furthermore, in the above configuration, it is preferable to further include a film formation step in which, after the self-assembled monolayer formation step, the self-assembled monolayer formed in the metal film formation region is used as a protective film to selectively form a film in the metal film non-formation region, and a removal step in which, after the film formation step, the self-assembled monolayer formed in the metal film formation region is removed under atmospheric pressure to expose the artificial oxide film.

[0016] According to the above configuration, in the film formation process, the self-assembled monolayer formed in the metal film formation region is used as a protective film for the metal film including the artificial oxide film, thereby selectively forming a film only in the areas where the metal film is not formed, and inhibiting the formation of a film on the artificial oxide film. Furthermore, by removing the self-assembled monolayer in the removal process, a substrate with a laminated structure in which the artificial oxide film and the film are exposed on the surface can be fabricated.

[0017] In the above configuration, it is preferable that the metal film is a copper film, and the artificial oxide film formation step is a step of oxidizing the surface of the copper film, whose surface has not been naturally oxidized, to form a copper(II) oxide film.

[0018] By oxidizing the surface of a copper film (isoelectric point: 7.7) as a metal film to form a copper(II) oxide film (isoelectric point: 9.5) as an artificial oxide film, it is possible to equalize and increase the isoelectric point in the metal film formation region as compared with the case where a natural oxide film is formed on the surface of the copper film. As a result, a self-assembled monolayer with a uniform and extremely high film density and suppressed or reduced occurrence of film defects and excellent function as a protective film can be formed.

[0019] In the above configuration, as the treatment liquid, a liquid containing a phosphonic acid compound having a phosphonic acid group adsorbed on the surface of the metal film and a solvent can be used.

[0020] The substrate processing apparatus of the present invention is a substrate processing apparatus for processing a substrate having a metal film formation region where a metal film is formed and a metal film non-formation region where the metal film is not formed on its surface, and includes an ultraviolet irradiation unit that forms an artificial oxide film by irradiating the non-naturally oxidized surface of the metal film with ultraviolet light under atmospheric pressure to oxidize the surface, a storage unit that stores a treatment liquid containing a material for forming a self-assembled monolayer, and a supply unit that supplies the treatment liquid to the surface of the substrate to form the self-assembled monolayer on the artificial oxide film in the metal film formation region.

[0021] According to the above configuration, by providing an ultraviolet irradiation unit, the surface of the metal film can be oxidized to form an artificial oxide film by irradiating the non-naturally oxidized metal film with ultraviolet light under atmospheric pressure. Then, by supplying the treatment liquid stored in the storage unit to the surface of the substrate after ultraviolet irradiation by the supply unit, a self-assembled monolayer can be formed on the artificial oxide film. That is, with the above configuration, compared with the case of forming a self-assembled monolayer on a metal film on which a natural oxide film is formed, the film density is uniform and high, the occurrence of film defects is also suppressed or reduced, and a substrate processing apparatus capable of forming a self-assembled monolayer excellent in function as a protective film can be provided.

[0022] Another substrate processing apparatus of the present invention is a substrate processing apparatus for processing a substrate having a metal film formation region where a metal film is formed and a metal film non-formation region where the metal film is not formed on its surface. By supplying an oxidizing treatment liquid to the non-naturally oxidized surface of the metal film under atmospheric pressure, an oxidizing treatment liquid supply unit that oxidizes the surface to form an artificial oxide film, a storage unit that stores a treatment liquid containing a material for forming a self-assembled monolayer, and a supply unit that supplies the treatment liquid to the surface of the substrate to form the self-assembled monolayer on the artificial oxide film of the metal film formation region. It is characterized by comprising.

[0023] According to the above configuration, by providing an oxidizing treatment liquid supply unit, an oxidizing treatment liquid can be supplied to a non-naturally oxidized metal film under atmospheric pressure to oxidize the surface of the metal film and form an artificial oxide film. Then, by supplying the treatment liquid stored in the storage unit to the substrate surface by the supply unit, a self-assembled monolayer can be formed on the artificial oxide film. That is, with the above configuration, compared to the case of forming a self-assembled monolayer on a metal film on which a natural oxide film is formed, the film density is uniform and high, and the occurrence of film defects is also suppressed or reduced, enabling the formation of a self-assembled monolayer with excellent function as a protective film. A substrate processing apparatus can be provided.

Effect of the Invention

[0024] According to the present invention, since an artificial oxide film is formed on a non-naturally oxidized metal film and then molecules for forming a self-assembled monolayer are adsorbed, the molecules can be adsorbed at a high density and uniformly. As a result, a self-assembled monolayer with a high and uniform film density and suppressed or reduced occurrence of film defects can be formed. That is, the present invention can provide a substrate processing method and a substrate processing apparatus capable of selectively forming a self-assembled monolayer with excellent function as a protective film.

Brief Description of the Drawings

[0025] [Figure 1]This flowchart shows an example of the overall flow of a substrate processing method according to an embodiment of the present invention. [Figure 2] This schematic diagram shows an example of a change in the state of a substrate in a substrate processing method according to an embodiment of the present invention, where Figure (a) shows the removal of a native oxide film formed on the surface of a metal film of the substrate, Figure (b) shows the formation of an artificial oxide film on the metal film surface from which the native oxide film has been removed, Figure (c) shows the supply of a self-assembled monolayer forming material to the substrate surface, and Figure (d) shows the formation of a self-assembled monolayer in the metal film formation region on the substrate surface. [Figure 3] This schematic diagram shows an example of a change in the state of a substrate in a substrate processing method according to an embodiment of the present invention, where Figure (a) shows the state in which a film is formed in a region of the substrate surface where a metal film is not formed, and Figure (b) shows the state in which the self-assembled monolayer in the metal film formation region of the substrate surface is removed. [Figure 4] This is an explanatory diagram illustrating the schematic of a processing liquid supply device provided in a substrate processing apparatus according to an embodiment of the present invention. [Figure 5] This is an explanatory diagram illustrating the schematic of an ultraviolet irradiation device provided in a substrate processing apparatus according to an embodiment of the present invention. [Figure 6] This is an explanatory diagram illustrating the schematic of a film deposition apparatus provided in a substrate processing apparatus according to an embodiment of the present invention. [Figure 7] This flowchart shows an example of the overall flow of a substrate processing method according to another embodiment of the present invention. [Figure 8] This is an explanatory diagram illustrating the schematic of an oxidizing treatment liquid storage section provided in an oxidizing treatment liquid supply device according to another embodiment of the present invention. [Figure 9] This is a schematic diagram illustrating a film deposition apparatus provided in a substrate processing apparatus according to another embodiment of the present invention. [Figure 10] Figure 10(a) shows a graph representing the X-ray photoelectron spectrum of the Cu film surface, and Figure 10(b) shows a graph representing the Auger electron spectroscopy spectrum of the Cu film surface. [Figure 11] This graph compares the atomic ratio (Al / (Al+Cu)) of each substrate in Example 1 and Comparative Example 1. [Modes for carrying out the invention]

[0026] (First Embodiment) A substrate processing method and a substrate processing apparatus according to the first embodiment of the present invention will be described below.

[0027] <Substrate Processing Method> First, the substrate processing method according to this embodiment will be described below with reference to Figures 1 to 3. Figure 1 is a flowchart showing an example of the overall flow of the substrate processing method according to the first embodiment of the present invention. Figures 2(a) to 2(d) are schematic diagrams showing an example of the change in the state of the substrate in the substrate processing method according to the embodiment of the present invention. Figure 2(a) shows the removal of the native oxide film formed on the metal film surface of the substrate, Figure 2(b) shows the formation of an artificial oxide film on the metal film surface from which the native oxide film has been removed, Figure 2(c) shows the supply of the self-assembled monolayer forming material to the substrate surface, and Figure 2(d) shows the formation of a self-assembled monolayer in the metal film formation region of the substrate surface. Furthermore, Figures 3(a) and 3(b) are schematic diagrams showing an example of the change in the state of the substrate in the substrate processing method according to the embodiment of the present invention. Figure 3(a) shows the formation of a film in the non-metal film formation region of the substrate surface, and Figure 3(b) shows the removal of the self-assembled monolayer in the metal film formation region of the substrate surface.

[0028] The substrate processing method of this embodiment provides a technique for selectively forming a film on the surface of a substrate W according to the material of the substrate surface. In this specification, "substrate" refers to various substrates such as semiconductor substrates, photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED (Field Emission Display) substrates, optical disc substrates, magnetic disc substrates, and magneto-optical disc substrates.

[0029] As shown in Figure 1, the substrate processing method of this embodiment includes at least a substrate W preparation step S101, a native oxide film removal step S102, an ultraviolet irradiation step (artificial oxide film formation step) S103, a self-assembled monolayer (hereinafter referred to as "SAM") formation step S104, a film formation step S105, and a removal step S106 for removing the SAM.

[0030] As shown in Figures 1 and 2(a), the substrate W prepared in the substrate preparation step S101 includes a metal film formation region where a metal film 1 is formed and a metal film non-formation region where an insulating film 2 is exposed. More specifically, the substrate W may include, for example, an insulating film 2 in which trenches of an arbitrary wiring width are formed and a metal film 1 embedded in the trenches. The substrate preparation step may include, for example, loading the substrate W into a chamber (details will be described later), which is a container for housing the substrate W, using a substrate loading / unloading mechanism.

[0031] In Figure 2(a), one metal film-forming region and one non-metal film-forming region are formed, but multiple regions of each may be formed. For example, a strip-shaped non-metal film-forming region may be interposed between adjacent strip-shaped metal film-forming regions, or a strip-shaped metal film-forming region may be interposed between adjacent strip-shaped non-metal film-forming regions.

[0032] Furthermore, the substrate W of this embodiment is not limited to a case where only a metal film formation region and a non-metal film formation region are provided on its surface. For example, there may be regions on the surface where other films made of materials different from the metal film 1 and the insulating film 2 are exposed and formed. In this case, the position where such regions are provided is not particularly limited and can be set arbitrarily.

[0033] The metal film 1 is not particularly limited and can be made of, for example, copper (Cu), tungsten (W), ruthenium (Ru), germanium (Ge), silicon (Si), titanium nitride (TiN), cobalt (Co), molybdenum (Mo), etc.

[0034] On the surface of the metal film 1, there is a native oxide film 3 formed by the oxidation of the surface of the metal film 1 through a reaction between the metal constituting the metal film 1 and oxygen in the air. For example, if the metal film 1 is a copper film, the metal film formation region contains a mixture of copper(I) oxide film (Cu2O film) and copper(II) oxide film (CuO film) as native oxide films, in addition to the copper film exposed on the surface. As a result, the surface state in the metal film formation region is non-uniform in terms of film properties such as isoelectric point.

[0035] Furthermore, the insulating film 2 is not particularly limited and can be made of, for example, silicon dioxide (SiO2), hafnium oxide (HfO2), zirconia (ZrO2), silicon nitride (SiN), etc.

[0036] The native oxide film removal step S102 is a step to remove the native oxide film 3 formed on the metal film 1, as shown in Figures 1 and 2(a). Examples of the native oxide film removal step S102 include acid cleaning, which involves bringing an acidic solution into contact with the native oxide film. The method of contact between the native oxide film 3 and the acidic solution is not particularly limited and includes methods such as directly supplying and coating the acidic solution onto the substrate W, spraying it, or immersing the substrate W in the acidic solution. One method of applying the acidic solution to the surface of the substrate W is to supply the acidic solution to the center of the substrate W's surface while the substrate W is rotated at a constant speed around its center as an axis. As a result, the acidic solution supplied to the surface of the substrate W flows from near the center of the substrate W's surface toward the periphery of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and diffuses over the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the acidic solution, forming a liquid film of the acidic solution, thereby enabling acid cleaning. The cleaning time for acid cleaning is not particularly limited and can be set as appropriate.

[0037] Examples of acidic solutions include inorganic acids and organic acids. Inorganic acids are not particularly limited and include, for example, sulfuric acid, hydrochloric acid, and hydrofluoric acid. Organic acids are also not particularly limited and include, for example, acetic acid and citric acid. The concentration of the acidic solution is not particularly limited and can be set according to the type and thickness of the native oxide film, the cleaning time, etc.

[0038] Furthermore, in the native oxide film removal step S102, a pretreatment cleaning may be performed before the acid cleaning using an acidic solution. This enables a neutral degreasing treatment to remove oil and other substances adhering to the substrate surface. The cleaning agent used for the pretreatment cleaning is not particularly limited, and examples include organic solvents such as acetone and ethanol. The method of pretreatment cleaning is also not particularly limited, and examples include a method of directly supplying and applying the cleaning agent to the substrate W, a method of spraying the cleaning agent, or a method of immersing the substrate W in the cleaning agent. As for the method of applying the cleaning agent to the surface of the substrate W, similar to the case of acid cleaning, one method is to supply the cleaning agent to the center of the surface of the substrate W while rotating the substrate W at a constant speed around its center as an axis. The cleaning time for the pretreatment cleaning is not particularly limited and can be set as appropriate. In addition, after the pretreatment cleaning, a water rinse may be performed before the acid cleaning with an acidic solution.

[0039] The ultraviolet irradiation step S103, as shown in Figures 1 and 2(b), is a step in which the surface of the metal film 1 after the native oxide film 3 has been removed is irradiated with ultraviolet light (wavelength range: 380 nm or less) under atmospheric pressure to oxidize the surface of the metal film 1 and form an artificial oxide film 4. By replacing the native oxide film 3 with the artificial oxide film 4 in this way, the surface state of the metal film formation region, which was non-uniform when the native oxide film 3 was present, and more specifically the isoelectric point, can be made uniform within the plane. For example, if the metal film 1 is a copper film (isoelectric point: 7.7), in the metal film formation region where the native oxide film 3 is formed on the surface of the copper film, the surface state is a mixture of the exposed copper film and the CuO film (isoelectric point: 9.5) and Cu2O film as native oxide films. However, by irradiating the copper film from which the native oxide film 3 has been removed with ultraviolet light to oxidize the surface of the copper film, a CuO film (isoelectric point: 9.5) as the artificial oxide film 4 can be formed. This suppresses the exposure of the copper film and also reduces the Cu2O film. Therefore, in the metal film formation region after the CuO film has formed on the surface of the copper film, the surface condition is more uniform compared to when the native oxide film is formed on the surface of the copper film, and the isoelectric point can also be raised compared to the metal film formation region when the native oxide film 3 has been removed and the copper film is exposed. In this specification, "atmospheric pressure" refers to an environment between 0.7 atmospheres and 1.3 atmospheres, centered around standard atmospheric pressure (1 atmosphere, 1013 hPa).

[0040] Furthermore, in the ultraviolet irradiation process S103, ultraviolet irradiation may be performed while the substrate W is rotated at a constant speed around its central axis. This makes it possible to uniformly distribute the integrated amount of ultraviolet light irradiated across the surface Wf of the substrate W.

[0041] Regarding the ultraviolet irradiation conditions, the irradiation intensity was 1 mW / cm². 2 More than 100mW / cm 2 The following range is preferred: 2.5 mW / cm² 2 More than 30mW / cm 2 The following range is more preferable: 5 mW / cm² 2 More than 15mW / cm 2 The following range is particularly preferred: UV irradiation intensity of 5 mW / cm²2 By doing the above, the surface of metal film 1 can be sufficiently oxidized. On the other hand, the ultraviolet irradiation intensity is set to 15 mW / cm². 2 The following steps can prevent the artificial oxide film 4 from becoming too thick. The ultraviolet irradiation time is preferably in the range of 0.016 hours or more and 1 hour or less, more preferably in the range of 0.4 hours or more and 0.64 hours or less, and particularly preferably in the range of 0.08 hours or more and 0.32 hours or less. By irradiating with ultraviolet light for 0.08 hours or more, the surface of the metal film 1 can be sufficiently oxidized. On the other hand, by irradiating with ultraviolet light for 0.32 hours or less, the artificial oxide film 4 can be prevented from becoming too thick. Furthermore, the peak wavelength of the irradiated ultraviolet light can be appropriately selected depending on the light source used. For example, it may include multiple peak wavelengths such as 185 nm and 254 nm.

[0042] The type of light source used to irradiate with ultraviolet light is not particularly limited and may be either a line light source or a point light source. The irradiation position of the ultraviolet light and the distance between the light source and the surface of the substrate W are not particularly limited and can be set as appropriate. For example, it is preferable to set the irradiation intensity of the ultraviolet light to be uniform across the surface of the substrate W, taking into consideration the area of ​​the substrate W and the irradiation area.

[0043] As shown in Figures 1, 2(c), and 2(d), the SAM formation step S104 involves bringing the processing solution into contact with the surface of the substrate W, thereby adsorbing the SAM forming material 5 contained in the processing solution onto the surface of the artificial oxide film 4, and thereby forming a SAM 6. Compared to the natural oxide film 3, the artificial oxide film 4 has a more uniform surface condition and a higher isoelectric point. Therefore, unlike the natural oxide film 3, the SAM forming material 5 can be adsorbed uniformly and at high density onto the artificial oxide film 4. As a result, a SAM 6 can be formed with a uniform and high film density, suppressing or reducing the occurrence of film defects, and exhibiting excellent protective film function.

[0044] The processing solution contains at least a material that forms a SAM (hereinafter referred to as "SAM-forming material") and a solvent. The SAM-forming material may be dissolved in the solvent or dispersed in it.

[0045] The SAM-forming material is not particularly limited, and examples include phosphonic acid compounds having a phosphonic acid group, such as monophosphonic acid and diphosphonic acid. These phosphonic acid compounds can be used individually or in combination of two or more.

[0046] Monophosphonic acids are not particularly limited, and examples include phosphonic acid compounds represented by the general formula RP(=O)(OH)2 (wherein R represents an alkyl group having 1 to 18 carbon atoms; an alkyl group having a fluorine atom within the range of 1 to 18 carbon atoms; or a vinyl group). In this specification, when a range of carbon atoms is expressed, that range means that all integer carbon atoms included in that range are included. Therefore, for example, an alkyl group having 1 to 3 carbon atoms means all alkyl groups having 1, 2, and 3 carbon atoms.

[0047] Alkyl groups with 1 to 18 carbon atoms may be linear or branched. Furthermore, the number of carbon atoms in the alkyl group is preferably in the range of 3 to 18, and more preferably in the range of 10 to 18. In addition, alkyl groups with 1 to 18 carbon atoms and containing a fluorine atom may be linear or branched. Furthermore, the number of carbon atoms in the alkyl group containing a fluorine atom is preferably in the range of 3 to 18, and more preferably in the range of 10 to 1.

[0048] Furthermore, specific examples of monophosphonic acids represented by RP(=O)(OH)2 include compounds represented by any of the following chemical formulas (1) to (16).

[0049] [ka]

[0050] In addition to the examples given above, any compound represented by one of the following chemical formulas (17) to (19) can also be used as a monophosphonic acid.

[0051] [ka]

[0052] Examples of diphosphonic acids include compounds represented by either of the following chemical formulas (20) or (21).

[0053] [ka]

[0054] Among the exemplified phosphonic acid compounds, octadecylphosphonic acid is preferred from the viewpoint of forming a dense SAM.

[0055] The solvent in the processing solution is not particularly limited, and examples include alcohol solvents, ether solvents, glycol ether solvents, glycol ester solvents, etc. The alcohol solvent is not particularly limited, and examples include ethanol. The ether solvent is not particularly limited, and examples include tetrahydrofuran (THF). The glycol ether solvent is not particularly limited, and examples include propylene glycol monomethyl ether (PGME). The glycol ester solvent is not particularly limited, and examples include propylene glycol monomethyl ether acetate (PGMEA). These solvents can be used alone or in mixtures of two or more. Furthermore, these solvents can be used in any combination with the phosphonic acid compounds exemplified above. From the viewpoint of being able to dissolve the phosphonic acid compounds among the exemplified solvents, alcohol solvents are preferred, and ethanol is particularly preferred.

[0056] The content of the SAM-forming material is preferably in the range of 0.0004% to 0.2% by mass, more preferably in the range of 0.004% to 0.08% by mass, and particularly preferably in the range of 0.04% to 0.06% by mass, relative to the total mass of the processing liquid.

[0057] Furthermore, the processing solution may contain known additives, provided that they do not hinder the effects of the present invention. The additives are not particularly limited and include, for example, stabilizers and surfactants.

[0058] SAM6 is selectively formed only on the metal film 1 in the metal film formation region of the substrate W, and not in the non-metal film formation region. The reason why SAM6 is formed only on the metal film 1 is that, for example, when the metal film 1 is a Cu (copper) film, the phosphonic acid groups of the phosphonic acid compound, which is the SAM forming material 5, react with the -OH groups on the surface of the Cu film as shown in the following chemical reaction equation.

[0059] [ka]

[0060] The method for bringing the processing solution into contact with the substrate W is not particularly limited, and examples include applying the processing solution to the surface of the substrate W, spraying the processing solution onto the surface of the substrate W, or immersing the substrate W in the processing solution.

[0061] One method for applying the processing solution to the surface of the substrate W is to rotate the substrate W at a constant speed around its center as an axis, and then supply the processing solution to the center of the substrate W's surface. As a result, the processing solution supplied to the surface of the substrate W flows from near the center of the substrate W's surface toward the periphery due to the centrifugal force generated by the rotation of the substrate W, and diffuses across the entire surface of the substrate W. Consequently, the entire surface of the substrate W is covered with the processing solution, and a liquid film of the processing solution is formed.

[0062] The SAM formation process S104 may include a step of removing the processing liquid remaining on the surface of the substrate W. The step of removing the processing liquid is not particularly limited and may include, for example, a step of heating the substrate W or a step of rotating the substrate W at a constant speed to shake off the processing liquid with centrifugal force.

[0063] In the step of heating the substrate W, the heating temperature of the substrate W is not particularly limited as long as the processing liquid can be sufficiently vaporized and removed, but is usually in the range of 0°C to 200°C, preferably 10°C to 150°C, and more preferably 20°C to 100°C. Similarly, the heating time is not particularly limited as long as the processing liquid can be sufficiently vaporized and removed, but is usually in the range of 0.0003 hours to 1 hour, preferably 0.0003 hours to 0.5 hours, and more preferably 0.0003 hours to 0.17 hours.

[0064] Furthermore, when performing the step of shaking off the processing liquid by centrifugal force, the rotation speed of the substrate W is not particularly limited as long as it is sufficient to shake off the processing liquid, but it is usually set in the range of 1 rpm to 3000 rpm, preferably 1 rpm to 2000 rpm, and more preferably 1 rpm to 1000 rpm.

[0065] Furthermore, the step of removing the processing liquid preferably includes a rinsing step in which a rinsing solution is brought into contact with the surface of the substrate W on which the processing liquid remains. In this case, the step of removing the processing liquid may, for example, involve first performing a rinsing step, followed by a heating step of the substrate W. This replaces the processing liquid on the surface Wf of the substrate W with the rinsing solution, and then removes the rinsing solution by heating. Alternatively, the step of removing the processing liquid may involve performing a centrifugal force shake-off step after the rinsing step. In this case, after replacing the processing liquid on the surface Wf of the substrate W with the rinsing solution, the rinsing solution can be shaken off the surface Wf of the substrate W by centrifugal force and removed. Including a rinsing step in the step of removing the processing liquid further prevents the processing liquid from remaining on the surface of the substrate W. Furthermore, it further prevents SAM from remaining on the surface of the substrate W (or the area of ​​the substrate W where the metal film is not formed) or from SAM from precipitation. As a result, selective film formation on the area where the metal film is not formed (details will be described later) can be performed even more effectively.

[0066] The method for bringing the rinsing solution into contact with the surface of the substrate W is not particularly limited. Examples include directly supplying and applying the rinsing solution to the substrate W, spraying it, or immersing the substrate W in the rinsing solution. One method for applying the rinsing solution to the surface of the substrate W is to supply the rinsing solution to the center of the substrate W's surface while the substrate W is rotated at a constant speed around its center as an axis. As a result, the rinsing solution supplied to the surface of the substrate W flows from near the center of the substrate W's surface toward the periphery due to the centrifugal force generated by the rotation of the substrate W, and diffuses over the entire surface of the substrate W. Consequently, the entire surface of the substrate W is covered with the rinsing solution, forming a liquid film of the rinsing solution, and the processing solution can be replaced with the rinsing solution. The duration of the rinsing process is not particularly limited and can be set as appropriate.

[0067] The rinsing solution is not particularly limited, and for example, any solvent applicable to the processing solution can be used. More specifically, examples of rinsing solutions include alcohol solvents, ether solvents, glycol ether solvents, glycol ester solvents, etc. The alcohol solvent is not particularly limited, and for example, ethanol can be used. The ether solvent is not particularly limited, and for example, tetrahydrofuran (THF) can be used. The glycol ether solvent is not particularly limited, and for example, propylene glycol monomethyl ether (PGME) can be used. The glycol ester solvent is not particularly limited, and for example, propylene glycol monomethyl ether acetate (PGMEA) can be used. These rinsing solutions can be used individually or in mixtures of two or more.

[0068] Furthermore, the processing solution used in the SAM formation process S104 may be subjected to a step to reduce the dissolved oxygen concentration in the processing solution beforehand (dissolved oxygen concentration reduction step). This reduces the oxidation of the metal film 1, which causes the metal to dissolve into the processing solution and etch the metal film 1.

[0069] The method for reducing the dissolved oxygen concentration in the processing liquid is not particularly limited and includes methods such as supplying an inert gas into the processing liquid and performing bubbling, or using a vacuum degasser or an oxygen permeable membrane. Examples of inert gases include nitrogen (N2) gas, helium (He) gas, neon (Ne) gas, and argon (Ar) gas.

[0070] When reducing the dissolved oxygen concentration in the treatment solution by bubbling with an inert gas, it is preferable to carry out this process under an inert gas atmosphere. This further reduces the dissolved oxygen concentration in the treatment solution. Furthermore, when carried out under an inert gas atmosphere, the oxygen concentration in the inert gas atmosphere is preferably less than 0.1%, more preferably 0.01% or less, and particularly preferably 0.001% or less. Reducing the dissolved oxygen concentration of the treatment solution under an inert gas atmosphere with an oxygen concentration of less than 0.1% prevents oxygen contained in the atmosphere from dissolving into the treatment solution, thereby further reducing the dissolved oxygen concentration in the treatment solution. As the inert gas, nitrogen (N2) gas, helium (He) gas, neon (Ne) gas, and argon (Ar) gas can be used.

[0071] The dissolved oxygen concentration of the processing solution after the dissolved oxygen concentration reduction step (or immediately before contacting the processing solution with the substrate W) is preferably less than 100 ppb, more preferably 10 ppb or less, and particularly preferably 1 ppb or less.

[0072] The film formation step S105 is a step in which the target film 7 is formed on the insulating film 2 in the metal film non-formation region, as shown in Figures 1 and 3(a). At this time, the SAM 6 formed in the metal film formation region functions as a protective mask for the metal film 1. The SAM 6 in this embodiment has a high and uniform film density, and the occurrence of film defects is suppressed or reduced, so it has excellent protective function. Therefore, selective film formation of the film 7 in the metal film non-formation region can be performed well.

[0073] The target film 7 is not particularly limited and includes, for example, films made of aluminum oxide (Al2O3), cobalt oxide (CoO), or zirconium oxide (ZrO2). The method for forming these films 7 is also not particularly limited and includes, for example, CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), vacuum deposition, sputtering, plating, thermal CVD, and thermal ALD.

[0074] The removal step S106 is a step to remove the SAM6 formed in the metal film formation region after the step of forming the film 7 has been performed, as shown in Figures 1 and 3(b). The method for removing the SAM6 is not particularly limited, and for example, a method of directly removing the SAM6 by dissolving or etching, or a method of thinly peeling off the surface layer of the metal film 1 together with the SAM6 can be used.

[0075] For example, to remove SAM6, which consists of a phosphonic acid compound, SAM6 can be removed by contacting it with acetic acid. As a result, as shown in Figure 3(b), a substrate W can be obtained in which film 7 is selectively formed only in areas where the metal film is not formed, and the metal film 1 is exposed.

[0076] Furthermore, when removing SAM6 by etching, it can be removed by, for example, contacting it with an oxygen-containing gas to gasify it. The oxygen-containing gas is not particularly limited and examples include oxygen (O2) gas and ozone (O3) gas. These oxygen-containing gases may be heated to a high temperature to promote the chemical reaction. These oxygen-containing gases may also be plasma-generated to promote the chemical reaction.

[0077] As described above, according to the substrate processing method of this embodiment, by forming the SAM6 using a processing solution with a reduced dissolved oxygen concentration, etching of the metal film 1 during the selective film formation process in the metal film formation region of the SAM6 can be suppressed.

[0078] <Substrate Processing Equipment> Next, the substrate processing apparatus according to this embodiment will be described below with reference to the drawings. The substrate processing apparatus of this embodiment comprises at least a processing liquid supply device for supplying processing liquid, an ultraviolet irradiation device for forming an artificial oxide film, a film formation device for forming SAM6, and a control unit for controlling each part of the substrate processing apparatus.

[0079] [Processing liquid supply device] As shown in Figure 4, the processing liquid supply device 100 according to this embodiment has the function of supplying processing liquid to the film deposition apparatus 300, and comprises at least a processing liquid tank 11, a pressurizing unit 12, and piping 13. Figure 4 is an explanatory diagram illustrating the schematic of the processing liquid supply device 100 in the substrate processing apparatus according to this embodiment.

[0080] The processing liquid tank 11 may include an agitation unit for agitating the processing liquid inside the tank 11, and a temperature control unit for adjusting the temperature of the processing liquid inside the tank 11 (neither of which are shown in the figures). The agitation unit may include a rotating unit for agitating the processing liquid inside the tank 11, and an agitation control unit for controlling the rotation of the rotating unit. The agitation control unit is electrically connected to the control unit 400, and the rotating unit may have, for example, a propeller-shaped agitation blade at the lower end of the rotating shaft. The control unit 400 issues an operation command to the agitation control unit to rotate the rotating unit, thereby agitating the processing liquid with the agitation blade. As a result, the concentration and temperature of the processing liquid inside the tank 11 can be made uniform.

[0081] The pressurization unit 12 includes a nitrogen gas supply source 16, which is the source of the gas that pressurizes the processing liquid tank 11; a pump (not shown) for pressurizing the nitrogen gas; a nitrogen gas supply pipe 14; and a valve 15 located along the path of the nitrogen gas supply pipe 14. The nitrogen gas supply source 16 is connected to the processing liquid tank 11 by pipeline via the nitrogen gas supply pipe 14. A pressure sensor (not shown) electrically connected to the control unit 400 can be installed inside the processing liquid tank 11. In this case, the control unit 400 can maintain the pressure inside the processing liquid tank 11 at a predetermined pressure higher than atmospheric pressure by controlling the operation of the pump based on the value detected by the pressure sensor. Furthermore, by electrically connecting the valve 15 to the control unit 400, the opening and closing of the valve 15 can be controlled by operation commands from the control unit 400.

[0082] The piping 13 is connected to the film deposition apparatus 300 via a pipeline. A valve 13a is provided along the route of the piping 13. The valve 13a is electrically connected to the control unit 400, and the opening and closing of the valve 13a can be controlled by operation commands from the control unit 400. When valves 13a and 15 are opened by operation commands from the control unit 400, the processing liquid is supplied (pressurized) to the film deposition apparatus 300 via the piping 13.

[0083] [Ultraviolet irradiation device] The ultraviolet irradiation device 200 will be explained based on Figure 5. Figure 5 is an explanatory diagram showing a schematic representation of the ultraviolet irradiation device 200 installed in the film deposition apparatus 300.

[0084] The ultraviolet irradiation device 200 is positioned inside the film deposition apparatus 300, above the substrate holding section (details of which will be described later) (in the direction indicated by arrow Z in Figure 5), so as to enable the irradiation of ultraviolet light onto the surface Wf of the substrate W held in the substrate holding section. The ultraviolet irradiation device 200 comprises at least a plurality of ultraviolet irradiation units 21 and quartz glass 22.

[0085] The ultraviolet irradiation unit 21 shown in Figure 5 is a line light source, and is arranged so that its longitudinal direction is parallel to the direction indicated by Y in Figure 5. Furthermore, each ultraviolet irradiation unit 21 is arranged in the direction indicated by arrow X so that they are equally spaced from one another. However, the ultraviolet irradiation unit of the present invention is not limited to this embodiment. For example, it may be a ring-shaped ultraviolet irradiation unit, with different diameters arranged concentrically. Alternatively, the ultraviolet irradiation unit may be a point light source. In this case, it is preferable that the multiple ultraviolet irradiation units are arranged so that they are equally spaced from one another in a plane.

[0086] The type of ultraviolet irradiation unit 21 is not particularly limited, and for example, low-pressure mercury lamps, high-pressure mercury lamps, excimer lamps, metal halide lamps, and UV (ultraviolet)-LEDs (light-emitting diodes) can be used. Furthermore, the multiple ultraviolet irradiation units 21 may be of the same type or different types. When using multiple different types of ultraviolet irradiation units 21, they can be arranged with varying peak wavelengths and light intensities.

[0087] The quartz glass 22 is positioned between the ultraviolet irradiation unit 21 and the substrate W. The quartz glass 22 is a plate-like body and is installed parallel to the horizontal direction. The quartz glass 22 has light transmittance, heat resistance, and corrosion resistance to ultraviolet light, and transmits ultraviolet light irradiated from the ultraviolet irradiation unit 21, enabling irradiation of the surface Wf of the substrate W. Furthermore, the quartz glass 22 can protect the ultraviolet irradiation unit 21 from the atmosphere inside the chamber 50 (details will be described later).

[0088] [Film forming equipment] Next, the film deposition apparatus 300 will be described based on Figure 6. Figure 6 is an explanatory diagram showing a schematic representation of the film deposition apparatus 300 provided in the substrate processing apparatus. Note that the ultraviolet irradiation apparatus 200 shown in Figure 5 is omitted from Figure 6.

[0089] The film deposition apparatus 300 according to this embodiment is a single-wafer type film deposition apparatus capable of depositing SAM 6 on a metal film formation region on which a metal film 1 has been formed.

[0090] As shown in Figure 6, the film deposition apparatus 300 includes at least a substrate holding section 30 for holding the substrate W, a supply section 40 for supplying a processing liquid to the surface Wf of the substrate W, a chamber 50 which is a container for housing the substrate W, and a splash-proof cup 60 for collecting the processing liquid. The film deposition apparatus 300 may also include loading / unloading means (not shown) for loading or unloading the substrate W.

[0091] The substrate holding section 30 is a means for holding the substrate W, and as shown in Figure 6, it holds the substrate W in a substantially horizontal position with the substrate surface Wf facing upward and rotates it. This substrate holding section 30 has a spin chuck 31 in which a spin base 33 and a rotating support shaft 34 are integrally coupled. The spin base 33 has a substantially circular shape in plan view, and a hollow rotating support shaft 34 extending substantially vertically is fixed to its center. The rotating support shaft 34 is connected to the rotation axis of a chuck rotation mechanism 36 including a motor. The chuck rotation mechanism 36 is housed in a cylindrical casing 37, and the rotating support shaft 34 is supported by the casing 37 so as to be rotatable around a vertical rotation axis.

[0092] The chuck rotation mechanism 36 can rotate the pivot shaft 34 around the rotation axis J by a drive from the chuck drive unit (not shown) of the control unit 400. As a result, the spin base 33 attached to the upper end of the pivot shaft 34 rotates around the rotation axis J. The control unit 400 can control the chuck rotation mechanism 36 via the chuck drive unit to adjust the rotation speed of the spin base 33.

[0093] Furthermore, the rotating support shaft 34 may be provided with a lifting mechanism 38, as shown in Figures 5 and 6. This lifting mechanism 38 is electrically connected to the control unit 400 and, in response to operation commands from the control unit 400, raises and lowers the spin base 33 and the rotating support shaft 34 in the vertical direction (indicated by arrow Z in Figure 6). This allows adjustment of the distance between the substrate W held in the substrate holding unit 30 and the ultraviolet irradiation device 200. For example, when loading or unloading the substrate W into or out of the film deposition apparatus 300, the spin base 33 and the rotating support shaft 34 are lowered by operation commands from the control unit 400 to separate the ultraviolet irradiation device 200 from the substrate W. On the other hand, when irradiating the surface Wf of the substrate W with ultraviolet light, the spin base 33 and the rotating support shaft 34 are raised by operation commands from the control unit 400 to bring the substrate W closer to the ultraviolet irradiation device 200. The distance at which the substrate W is brought closer to the ultraviolet irradiation device 200 is not particularly limited and can be set appropriately according to the ultraviolet irradiation intensity and irradiation time. Furthermore, the lifting mechanism 38 can be, for example, an air cylinder, a ball screw mechanism, or a single-axis stage. In addition, the lifting mechanism 38 may be surrounded by a bellows.

[0094] Multiple chuck pins 35 are erected near the periphery of the spin base 33 for gripping the peripheral edge of the substrate W. The number of chuck pins 35 is not particularly limited, but it is preferable to provide at least three or more in order to securely hold the circular substrate W. In this embodiment, three are arranged at equal intervals along the periphery of the spin base 33. Each chuck pin 35 includes a substrate support pin that supports the peripheral edge of the substrate W from below, and a substrate holding pin that presses against the outer peripheral end face of the substrate W supported by the substrate support pin to hold the substrate W.

[0095] The supply unit 40 is positioned above the substrate holding unit 30 and supplies the processing liquid supplied from the processing liquid supply device 100 onto the surface Wf of the substrate W. The supply unit 40 has a nozzle 41 and an arm 42. The nozzle 41 is attached to the tip of the horizontally extending arm 42 and is positioned above the spin base 33 when discharging the processing liquid. The supply unit 40 also has a supply unit lifting mechanism 43. The supply unit lifting mechanism 43 is connected to the arm 42.

[0096] The supply unit lifting mechanism 43 is electrically connected to the control unit 400, and the supply unit 40 can be raised or lowered in response to operation commands from the control unit 400. This allows the nozzle 41 of the supply unit 40 to move closer to or further away from the substrate W held in the substrate holding unit 30, and the distance between the nozzle 41 and the surface Wf of the substrate W can be adjusted.

[0097] Furthermore, when loading or unloading the substrate W into or out of the film deposition apparatus 300, the supply unit lifting mechanism 43 is activated by an operation command from the control unit 400 to raise the supply unit 40. This allows the nozzle 41 and the surface Wf of the substrate W to be separated by a certain distance, making it easier to load and unload the substrate W.

[0098] The splash-proof cup 60 is positioned to surround the spin base 33. The splash-proof cup 60 is connected to a lifting drive mechanism (not shown) and is capable of moving up and down. When supplying the processing liquid to the surface Wf of the substrate W, the splash-proof cup 60 is positioned in a predetermined position by the lifting drive mechanism and surrounds the substrate W, which is held by the chuck pin 35, from a lateral position. This allows the processing liquid splashing from the substrate W and the spin base 33 to be collected.

[0099] In the above description, the substrate processing apparatus of the present invention has been described using the example of a single-wafer type film deposition apparatus. However, the substrate processing apparatus of the present invention is not limited to this embodiment and can also be applied when the film deposition apparatus is a batch type.

[0100] [Control Unit] The control unit 400 is electrically connected to each part of the substrate processing apparatus and controls the operation of each part. The control unit 400 is composed of a computer having an arithmetic unit and a memory unit. A CPU is used as the arithmetic unit to perform various arithmetic operations. The memory unit includes a ROM, which is a read-only memory for storing the substrate processing program, a RAM, which is a read-write memory for storing various information, and a magnetic disk for storing control software and data. Substrate processing conditions, including the ultraviolet irradiation conditions for forming the artificial oxide film and the film deposition conditions for SAM6, are pre-stored on the magnetic disk. The CPU reads the substrate processing conditions into the RAM and controls each part of the substrate processing apparatus according to its contents.

[0101] (Second Embodiment) A substrate processing method and substrate processing apparatus according to a second embodiment of the present invention will be described below.

[0102] <Substrate Processing Method> The substrate processing method of this embodiment will be described below with reference to Figure 7. Figure 7 is a flowchart showing an example of the overall flow of the substrate processing method according to the second embodiment of the present invention.

[0103] The substrate processing method of this embodiment differs from the artificial oxide film formation step in that the ultraviolet irradiation step S103 is replaced with an oxidizing treatment solution contact step S103', as shown in Figure 7. Even with this configuration, this embodiment allows for the selective formation of a self-assembled monolayer as a protective film on the substrate, with a uniform and high film density and suppression or reduction of film defects. The other steps are the same as in the first embodiment, so their detailed explanation is omitted.

[0104] The oxidizing treatment solution contact step S103' is a step similar to the ultraviolet irradiation step S103 in which an artificial oxide film 4 is formed on the metal film 1 after the native oxide film 3 has been removed, under atmospheric pressure. Specifically, the oxidizing treatment solution is brought into contact with the metal film 1 after the native oxide film 3 has been removed to oxidize and form the artificial oxide film 4. The method of contacting with the oxidizing treatment solution is not particularly limited and includes methods such as applying the oxidizing treatment solution to the surface of the substrate W, spraying the treatment solution to the surface of the substrate W, or immersing the substrate W in the treatment solution.

[0105] One method for applying the oxidizing treatment solution to the surface Wf of a substrate W is to rotate the substrate W at a constant speed around its center as an axis, and supply the oxidizing treatment solution to the center of the substrate W's surface. As a result, the oxidizing treatment solution supplied to the surface of the substrate W flows from near the center of the substrate W's surface toward the periphery of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and diffuses over the entire surface of the substrate W. Consequently, the entire surface of the substrate W is covered with the oxidizing treatment solution, and a liquid film of the oxidizing treatment solution is formed.

[0106] The oxidizing solution is not particularly limited as long as it can form an artificial oxide film 4 on the surface of the metal film 1 from which the native oxide film 3 has been removed. Examples of oxidizing solutions include ozonated water.

[0107] When using ozonated water as the oxidizing treatment solution, the ozone concentration is preferably in the range of 1 ppm to 20 ppm, more preferably in the range of 5 ppm to 20 ppm, and particularly preferably in the range of 10 ppm to 20 ppm. By setting the ozonated water concentration to 10 ppm or higher, the surface of the metal film 1 can be sufficiently oxidized. On the other hand, by setting the ozonated water concentration to 20 ppm or lower, it is possible to prevent the thickness of the artificial oxide film 4 from becoming too thick.

[0108] The temperature of the oxidizing solution (more specifically, the temperature of the solution immediately before supplying it to the surface Wf of the substrate W) is preferably in the range of 1°C to 80°C, more preferably in the range of 10°C to 80°C, and particularly preferably in the range of 20°C to 80°C. By setting the temperature of the oxidizing solution to 20°C or higher, the surface of the metal film 1 can be sufficiently oxidized. On the other hand, by setting the temperature of the oxidizing solution to 80°C or lower, it is possible to prevent the thickness of the artificial oxide film 4 from becoming too thick.

[0109] Furthermore, in the oxidizing treatment solution contact step S103', after forming an artificial oxide film by contact with the oxidizing treatment solution, a drying step of the remaining oxidizing treatment solution may be performed before the SAM formation step S104.

[0110] <Substrate Processing Equipment> Next, the substrate processing apparatus according to this embodiment will be described below with reference to the drawings. The substrate processing apparatus according to the second embodiment has basically the same configuration as the substrate processing apparatus according to the first embodiment, except that it is equipped with an oxidizing treatment liquid supply device instead of an ultraviolet irradiation device and does not have a lifting mechanism 38 in the substrate holding section 30. Furthermore, the control unit according to the second embodiment has the same configuration as the control unit 400 according to the first embodiment, except that it has the function of controlling the oxidizing treatment liquid supply device. In the following description, the case in which the oxidizing treatment liquid is ozonated water will be used as an example for the oxidizing treatment liquid supply device. Also in the following description, components that have the same function as those in the substrate processing apparatus according to the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0111] [Oxidizing treatment liquid supply device] As shown in Figures 8 and 9, the oxidizing liquid supply device 500 comprises at least an oxidizing liquid storage unit 70 and an oxidizing liquid supply unit 80. Figure 8 is an explanatory diagram showing a schematic representation of the oxidizing liquid storage unit 70 in the oxidizing liquid supply device 500 according to this embodiment. Figure 9 is an explanatory diagram showing a schematic representation of the substrate processing apparatus according to this embodiment.

[0112] As shown in Figure 8, the oxidizing treatment liquid storage unit 70 includes at least an oxidizing treatment liquid tank 71, a pure water supply unit 72, an ozone gas supply unit 73, and an oxidizing treatment liquid supply pipe 74.

[0113] The oxidizing treatment solution tank 71 stores ozonated water as an oxidizing treatment solution. Ozonated water is produced in the oxidizing treatment solution tank 71 by dissolving ozone gas supplied from the ozone gas supply unit 73 into pure water supplied from the pure water supply unit 72.

[0114] The pure water supply unit 72 includes a pure water supply source 75, a pure water supply pipe 76, and a valve 76a located along the path of the pure water supply pipe 76. The pure water supply source 75 is pipelinely connected to the oxidizing treatment liquid tank 71 by the pure water supply pipe 76. By electrically connecting the valve 76a to the control unit 400', the opening and closing of the valve 76a can be controlled by the operation commands of the control unit 400'. When the valve 76a is opened by the operation command of the control unit 400', pure water is pumped through the pure water supply pipe 76.

[0115] The ozone gas supply unit 73 includes an ozone gas supply source 77, an ozone gas supply pipe 78, and a valve 78a located along the path of the ozone gas supply pipe 78. The ozone gas supply source 77 is pipelinely connected to the oxidizing liquid tank 71 by the ozone gas supply pipe 78. By electrically connecting the valve 78a to the control unit 400', the opening and closing of the valve 78a can be controlled by operation commands from the control unit 400'. When the valve 78a is opened by an operation command from the control unit 400', ozone gas is pumped through the ozone gas supply pipe 78. Furthermore, by controlling, for example, the opening time of the valve 78a using operation commands from the control unit 400', the amount of ozone gas supplied to the oxidizing liquid tank 71 can be adjusted. This allows the control unit 400' to control the ozone concentration of the ozonated water produced in the oxidizing liquid tank 71.

[0116] The oxidizing treatment liquid supply pipe 74 is connected by pipeline to the oxidizing treatment liquid tank 71 and the oxidizing treatment liquid supply unit 80 (details will be described later). A valve 74a is provided in the middle of the oxidizing treatment liquid supply pipe 74. The valve 74a is electrically connected to the control unit 400', and the opening and closing of the valve 74a can be controlled by the operation command of the control unit 400'. When the valve 74a is opened by the operation command of the control unit 400', the ozonated water stored in the oxidizing treatment liquid tank 71 can be supplied to the oxidizing treatment liquid supply unit 80.

[0117] As shown in Figure 9, the oxidizing liquid supply unit 80 is positioned above the substrate holding unit 30 and supplies the treatment liquid from the oxidizing liquid tank 71 of the oxidizing liquid storage unit 70 onto the surface Wf of the substrate W. The oxidizing liquid supply unit 80 has a nozzle 81 and an arm 82. The nozzle 81 is attached to the tip of the horizontally extending arm 82 and is positioned above the spin base 33 (in the direction indicated by arrow Z in Figure 9) when discharging the treatment liquid. The oxidizing liquid supply unit 80 also has an oxidizing liquid supply unit lifting mechanism 83. The oxidizing liquid supply unit lifting mechanism 83 is connected to the arm 82.

[0118] The oxidizing liquid supply unit lifting mechanism 83 is electrically connected to the control unit 400', and the oxidizing liquid supply unit 80 can be raised and lowered vertically (in the direction indicated by arrow Z in Figure 9) in response to operation commands from the control unit 400'. This allows the nozzle 81 of the oxidizing liquid supply unit 80 to move closer to or further away from the substrate W held in the substrate holding unit 30, thereby adjusting the distance between the nozzle 81 and the surface Wf of the substrate W.

[0119] Furthermore, when loading or unloading the substrate W into or out of the film deposition apparatus 300, the oxidizing treatment liquid supply unit lifting mechanism 83 is activated by an operation command from the control unit 400', raising the oxidizing treatment liquid supply unit 80. This allows the nozzle 81 and the surface Wf of the substrate W to be separated by a certain distance, making it easier to load and unload the substrate W.

[0120] [Control Unit] The control unit 400' is electrically connected to each part of the substrate processing apparatus and controls the operation of each part. The control unit 400' is composed of a computer having an arithmetic unit and a storage unit, similar to the control unit 400 of the first embodiment. The hardware configuration of the arithmetic unit and the storage unit is the same as in the first embodiment. In addition, the storage unit (magnetic disk) pre-stores substrate processing conditions, including conditions for forming an artificial oxide film such as the concentration of the oxidizing treatment solution (ozone concentration if the oxidizing treatment solution is ozonated water) and temperature, and film formation conditions for SAM6. The CPU reads the substrate processing conditions into RAM and controls each part of the substrate processing apparatus according to its contents.

[0121] (Other matters) The processing liquid supply device, ultraviolet irradiation device, and oxidizing processing liquid supply device described in each embodiment may be used in various devices other than substrate processing devices, or they may be used independently. The above description has described the most preferred embodiments of the present invention. However, the present invention is not limited to these embodiments. The components in the above embodiments and each of the modifications can be changed, modified, replaced, added, deleted, and combined within a range that is not inconsistent with each other. [Examples]

[0122] Preferred embodiments of this invention are described below in detail. However, unless otherwise specified, the materials, proportions, conditions, etc., described in these embodiments do not limit the scope of this invention to those described.

[0123] (Example 1) [Preparation process for circuit boards] First, a substrate was prepared in which a Cu film (thickness 100 nm, metal film formation region) was formed on the surface as a metallic film.

[0124] [Natural oxide film removal process] Next, the natural oxide film formed on the surface of the Cu film on the substrate was removed. Specifically, first, the substrate was immersed in acetone for 10 minutes to remove the oil on the substrate surface. Subsequently, the substrate was immersed in dilute sulfuric acid (sulfuric acid: pure water = 1:20 (volume ratio)) for 2 minutes to remove the natural oxide film formed on the surface of the Cu film.

[0125] [Artificial Oxide Film Formation Step] Next, an artificial oxide film was formed on the Cu film after removing the natural oxide film. Specifically, the substrate was transported to a chamber as shown in FIG. 5, and ultraviolet irradiation was performed using an ultraviolet irradiation device. As a result, a CuO film as an artificial oxide film was formed on the surface of the Cu film. The ultraviolet irradiation conditions were as follows. Light source of the ultraviolet irradiation unit: Low-pressure mercury lamp (product name: EUV200WS-51, manufactured by Sen Special Light Source Co., Ltd.) Peak wavelength of ultraviolet light: 185 nm, 254 nm Irradiation intensity of ultraviolet light: 10 mW / cm 2 Irradiation time of ultraviolet light: 0.16 hours Pressure inside the chamber: Atmospheric pressure Temperature inside the chamber: 25 °C Atmosphere inside the chamber: Air

[0126] [Formation of SAM and Al2O3 Film] Octadecylphosphonic acid (CH3(CH2) 17 P(=O)(OH)2) was dissolved in an ethanol solvent to prepare a treatment solution. The concentration of octadecylphosphonic acid was 0.05% by mass based on the total mass of the treatment solution.

[0127] Next, using the treatment solution, a SAM was formed on the surface of the substrate after forming the artificial oxide film. Specifically, using a film forming apparatus as shown in FIG. 6, the treatment solution was applied to the surface of the substrate, and a SAM formed by the adsorption of octadecylphosphonic acid on the Cu film was formed.

[0128] Furthermore, an Al2O3 film was formed on the substrate surface. Specifically, the Al2O3 film was deposited using the ALD method with an atomic layer deposition apparatus (product name: SUNALE-R, manufactured by PICOSUN Corporation).

[0129] [SAM removal] Next, the SAM was removed from the substrate on which the Al2O3 film was formed. Specifically, the substrate was immersed in acetic acid (100% by mass) with ultrasonic vibration applied, and the SAM was dissolved and removed by the acetic acid. As a result, a substrate was fabricated on which an artificial oxide film, the CuO film, was formed on the Cu film.

[0130] (Comparative Example 1) In this comparative example, SAM and Al2O3 films were deposited on the Cu film after the removal of the native oxide film without depositing an artificial oxide film. Otherwise, the same process as in Example 1 was followed to produce a substrate with a native oxide film formed on the Cu film.

[0131] (Evaluation of surface condition) The surface state of the Cu film was analyzed and evaluated for the untreated substrate before removal of the native oxide film, as well as for each substrate related to Example 1 and Comparative Example 1. Specifically, the surface state of the Cu film was analyzed using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The results are shown in Figures 10(a) and 10(b). Figure 10(a) is a graph representing the X-ray photoelectron spectrum on the Cu film, and Figure 10(b) is a graph representing the Auger electron spectroscopy spectrum on the Cu film.

[0132] As can be seen from Figures 10(a) and 10(b), on the untreated substrate, peaks appeared in the binding energy values ​​and kinetic energy values ​​specific to Cu atoms, Cu2O, and CuO on the Cu film. This confirmed that on the Cu film of the untreated substrate, exposed Cu film, Cu2O film, and CuO film are mixed together, forming a native oxide film with a non-uniform film quality.

[0133] In the substrate of Comparative Example 1, the strongest peaks appeared in the binding energy and kinetic energy values ​​specific to Cu atoms on the Cu film. This confirmed that the native oxide film had been removed from the Cu film surface in the substrate of Comparative Example 1. On the other hand, in the substrate of Example 1, strong main and satellite peaks appeared in the binding energy and kinetic energy values ​​specific to CuO. This confirmed that a CuO film, as an artificial oxide film, had been formed on the Cu film surface in the substrate of Example 1.

[0134] (SAM performance evaluation) Next, the performance of each substrate in Example 1 and Comparative Example 1 as a protective film for SAM was evaluated. Specifically, in the measurement of the X-ray photoelectron spectrum using the aforementioned XPS, the 2p of Cu atoms was evaluated. 3 / 2 The peak area of ​​the measurement peak for the 2s orbital of the Al atom was determined, and after correcting for the sensitivity coefficient, the corrected peak area for each measurement peak of the Cu and Al atoms was calculated. Using the obtained surface atomic concentrations of Cu and Al atoms, the atomic ratio (Al / (Al+Cu)) was calculated using the following formula. Atomic ratio (Al / (Al+Cu)) = (Al atom concentration determined based on the peak area of ​​the 2s orbital spectrum of Al atoms in XPS analysis) / ((Al atom concentration determined based on the peak area of ​​the 2s orbital spectrum of Al atoms in XPS analysis) + (2p of Cu atoms in XPS analysis) 3 / 2 Cu atom concentration determined based on the peak area of ​​the orbital spectrum. The results are shown in Figure 11. Figure 11 is a graph comparing the atomic ratio (Al / (Al+Cu)) of each substrate in Example 1 and Comparative Example 1.

[0135] As can be seen from Figure 11, in Comparative Example 1, where a SAM was formed on the native oxide film of the Cu film without forming an artificial oxide film, the atomic ratio on the Cu film was 0.44, confirming a high proportion of Al atoms. This indicates that Comparative Example 1, where a SAM was formed on the native oxide film of the Cu film, did not function sufficiently as a protective film when depositing the Al2O3 film.

[0136] On the other hand, in the substrate of Example 1, where the SAM was formed on a CuO film, an artificial oxide film, the atomic ratio on the Cu film was reduced to 0.03, confirming that the proportion of Al atoms was sufficiently suppressed. This confirmed that in Example 1, forming the SAM on a CuO film significantly improved the protective function of the SAM compared to forming the SAM on a Cu film from which the native oxide film had been removed. This is presumed to be because forming the SAM on a CuO film improved the film density of the SAM and sufficiently suppressed film defects. [Explanation of Symbols]

[0137] 1. Metal film 2 insulating film 3. Native oxide film 4 Artificial oxide film 5. SAM-forming materials (Self-assembled monolayer-forming materials) 6 SAM (Self-assembled monolayer) 11. Treatment liquid tank 12 Pressurized section 13 Piping 13a valve 14 Nitrogen gas supply pipe 15 valves 16 Nitrogen gas supply sources 21 UV irradiation area 22 Quartz glass 30 Board holding part 40 Supply section 41 nozzles 42 Arms 43. Supply Unit Lifting Mechanism 50 Chambers 60 splash-proof cups 70 Oxidizing treatment liquid storage section 71 Oxidizing treatment liquid tank 72 Pure water supply section 73 Ozone Gas Supply Department 74. Oxidizing treatment liquid supply pipe 75 Pure water source 76 Pure water supply pipe 77 Ozone gas supply sources 78 Ozone gas supply pipe 80 Oxidizing treatment liquid supply unit 81 nozzles 82 Arm 83 Lifting mechanism for oxidizing treatment liquid supply unit 100 Processing liquid supply device 200 Ultraviolet irradiation device 300 Film deposition equipment 400, 400' Control Unit 500 Oxidizing treatment liquid supply device S101 Preparation process S102 Natural oxide film removal process S103 Ultraviolet irradiation process (artificial oxide film formation process) S103' Oxidizing treatment solution contact process (artificial oxide film formation process) S104 SAM (self-assembled monolayer) formation process S105 Film formation process S106 Removal process W board Wf substrate surface

Claims

1. A substrate processing method for processing a substrate having a metal film-forming region on its surface and a metal film-non-forming region on its surface where the metal film is not formed, An artificial oxide film formation step involves oxidizing the surface of the metal film that has not undergone natural oxidation under atmospheric pressure to form an artificial oxide film. A self-assembled monolayer formation step involves forming the self-assembled monolayer on the artificial oxide film by bringing a processing solution containing a material for forming a self-assembled monolayer into contact with at least the surface of the substrate, A substrate processing method including the following.

2. The substrate processing method according to claim 1, wherein the artificial oxide film formation step is a step of irradiating the surface of the metal film, whose surface has not been naturally oxidized, with ultraviolet light.

3. The substrate processing method according to claim 1, wherein the artificial oxide film formation step is a step of bringing an oxidizing treatment solution into contact with the surface of the metal film whose surface has not been naturally oxidized.

4. The substrate processing method according to any one of claims 1 to 3, wherein the artificial oxide film formation step is a step of forming the artificial oxide film by oxidizing the surface of the metal film whose surface has not been naturally oxidized, thereby making the isoelectric point of the metal film formation region more uniform and higher in the plane than before the artificial oxide film was formed.

5. A substrate processing method according to any one of claims 1 to 4, further comprising a native oxide film removal step of removing a native oxide film formed on the surface of the metal film before the artificial oxide film formation step.

6. The substrate processing method according to claim 5, wherein the native oxide film removal step is a step of removing the native oxide film by contacting the native oxide film with an acidic solution.

7. Following the self-assembled monolayer formation step, a film formation step is performed in which the self-assembled monolayer formed in the metal film formation region is used as a protective film to selectively form a film in the metal film non-formation region. After the film formation step, a removal step is performed to remove the self-assembled monolayer formed in the metal film formation region under atmospheric pressure to expose the artificial oxide film. A substrate processing method according to any one of claims 1 to 6, further comprising the above.

8. The aforementioned metal film is a copper film, The substrate processing method according to any one of claims 1 to 7, wherein the artificial oxide film formation step is a step of oxidizing the surface of the copper film whose surface has not been naturally oxidized to form a copper(II) oxide film.

9. The substrate treatment method according to any one of claims 1 to 8, wherein the treatment solution comprises a phosphonic acid compound having a phosphonic acid group adsorbed on the surface of the metal film and a solvent.

10. A substrate processing apparatus having a metal film forming region on its surface and a metal film non-forming region on its surface where the metal film is not formed, A UV irradiation unit that irradiates the surface of the metal film that has not undergone natural oxidation with ultraviolet light under atmospheric pressure to oxidize the surface and form an artificial oxide film, A storage section for storing a processing solution containing materials for forming a self-assembled monolayer, A supply unit that supplies the processing liquid to the surface of the substrate to form the self-assembled monolayer on the artificial oxide film in the metal film formation region, A substrate processing apparatus equipped with the following:

11. A substrate processing apparatus having a metal film forming region on its surface and a metal film non-forming region on its surface where the metal film is not formed, An oxidizing treatment liquid supply unit that supplies an oxidizing treatment liquid to the surface of the metal film that has not undergone natural oxidation under atmospheric pressure, thereby oxidizing the surface and forming an artificial oxide film, A storage section for storing a processing solution containing materials for forming a self-assembled monolayer, A supply unit that supplies the processing liquid to the surface of the substrate to form the self-assembled monolayer on the artificial oxide film in the metal film formation region, A substrate processing apparatus equipped with the following:

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