TWI840090B - Substrate processing method and substrate processing device - Google Patents

Abstract

The present invention provides a substrate processing method and a substrate processing device for selectively forming a self-assembled monolayer film, wherein the self-assembled monolayer film improves the function of a protective film by making the film density uniform and high, and suppressing or reducing the generation of film defects. The substrate processing method of the present invention processes a substrate having a metal film forming region on the surface of which a metal film 1 is formed and a metal film non-forming region on which the metal film 1 is not formed, and includes: an artificial oxide film forming step, which is to oxidize the non-naturally oxidized surface of the metal film 1 under atmospheric pressure to form an artificial oxide film 4; and a self-assembled monolayer film forming step, which is to form a self-assembled monolayer film 6 on the artificial oxide film 4 by allowing a processing liquid containing a material for forming the self-assembled monolayer film 6 to at least contact the surface of the substrate.

Description

Substrate processing method and substrate processing device

The present invention relates to a substrate processing method and a substrate processing device which can form a self-assembled monolayer (SAM) on a substrate with high film density and suppress or reduce film defects.

In the manufacture of semiconductor devices, photolithography is widely used as a technique for selectively forming a film on a specific surface area of a substrate. For example, an insulating film is formed after forming the lower layer wiring, and a double-track metal inlay structure with trenches and vias is formed by photolithography and etching, and a conductive film such as Cu is embedded in the trenches and vias to form wiring.

However, recently, as semiconductor devices have become increasingly sophisticated, photolithography may have insufficient alignment accuracy. Therefore, a method of selectively forming a film on a specific area on the surface of a substrate with high precision is needed to replace photolithography.

For example, Patent Document 1 discloses a film forming method, which forms a self-assembled monomolecular film on the surface of a substrate region where film formation is not desired, and selectively forms a film on a substrate region where SAM is not formed. According to the film forming method, by using a solvent having an optimal dielectric constant, more specifically, using a mixed solvent containing propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA) as a processing solution for forming SAM, it is possible to suppress the reduction in the coverage of SAM and prevent the selectivity of the processing solution to the metal film from being reduced.

Here, for example, when the substrate contains copper, the substrate surface becomes a state where a natural oxide film containing a copper (I) oxide film (CuO film) or a copper (II) oxide film (CuO film) is mixed in addition to the exposed Cu. Therefore, it is difficult for the molecules forming the SAM to be adsorbed uniformly and at a high density on the substrate surface. As a result, there is a problem that film defects appear in the part where the molecules forming the SAM cannot be attached, and a SAM with a small and uneven film density is formed. [Prior art literature] [Patent literature]

[Patent Document 1] U.S. Patent No. 10,867,850

[The problem the invention is trying to solve]

The present invention is made in view of the above-mentioned problems, and its purpose is to provide a substrate processing method and substrate processing device that can selectively form a self-assembled monomolecular film, wherein the self-assembled monomolecular film improves the function as a protective film by making the film density uniform and improving and suppressing or reducing the generation of film defects. [Technical means for solving the problem]

The substrate processing method of the present invention is to solve the above-mentioned problems, and its characteristics are: it processes a substrate having a metal film forming area on the surface of which a metal film is formed and a metal film non-forming area on which the above-mentioned metal film is not formed, and includes: an artificial oxide film forming step, which is to oxidize the non-naturally oxidized surface of the above-mentioned metal film under atmospheric pressure to form an artificial oxide film; and a self-assembled monomolecular film forming step, which is to form the above-mentioned self-assembled monomolecular film on the above-mentioned artificial oxide film by allowing a processing liquid containing a material for forming a self-assembled monomolecular film to at least contact the surface of the above-mentioned substrate.

In a metal film whose surface has been naturally oxidized, for example, in the case where the metal film is a copper film, a natural oxide film including a copper oxide (I) film or a copper oxide (II) film is mixed and formed. In addition, since the natural oxide film is not formed uniformly, there are also portions where the metal film is exposed. As a result, the surface state of the naturally oxidized metal film is not uniform. However, if it is the above-mentioned structure, an artificial oxide film is formed by oxidizing the surface of the metal film whose surface has not been naturally oxidized, and the surface state can be made uniform compared to the metal film formed with the natural oxide film. Thereby, the molecules forming the self-assembled monolayer can be adsorbed on the artificial oxide film more uniformly and at a high density compared to the case where they are adsorbed on the metal film formed with the natural oxide film. As a result, if it is the above-mentioned structure, the self-assembled monolayer can be formed with a high film density and with the defects of the film suppressed or reduced.

In the above configuration, the artificial oxide film forming step may be a step of irradiating the surface of the metal film which has not been naturally oxidized with ultraviolet rays.

Furthermore, the artificial oxide film forming step may be a step of bringing an oxidizing treatment liquid into contact with the surface of the metal film which has not been naturally oxidized.

In the above configuration, it is preferred that the artificial oxide film forming step is the following step: 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 forming region more uniform and higher in the surface than before the artificial oxide film is formed. By forming the artificial oxide film, the isoelectric point of the metal film forming region is made uniform and higher, thereby, when, for example, a compound having anionic functional groups is used as a material for forming a self-assembled monolayer, the compound can be uniformly and densely adsorbed on the artificial oxide film by the acid-base reaction between the surface of the artificial oxide film and the anionic functional groups. In this way, a self-assembled monolayer with a uniform and higher film density and suppressed or reduced film defects can be formed.

Furthermore, in the above configuration, it is preferred to include a natural oxide film removal step of removing the natural oxide film formed on the surface of the metal film before the artificial oxide film forming step. If the metal film is in contact with air at room temperature, for example, the metal on the surface reacts with oxygen in the air to form a natural oxide film on the surface of the metal film. However, as in the above configuration, the natural oxide film is removed in advance before the artificial oxide film forming step, thereby preparing a substrate with the metal film exposed on the surface.

Furthermore, in the above-mentioned structure, the above-mentioned natural oxide film removal step may be a step of removing the above-mentioned natural oxide film by bringing an acidic solution into contact with the above-mentioned natural oxide film.

Furthermore, in the above-mentioned structure, it is preferred to further include: a film forming step, which is after the above-mentioned self-assembled monolayer film forming step, using the above-mentioned self-assembled monolayer film formed in the above-mentioned metal film forming area as a protective film to selectively form a film in the above-mentioned metal film non-forming area; and a removal step, which is after the above-mentioned film forming step, removing the above-mentioned self-assembled monolayer film formed in the above-mentioned metal film forming area under atmospheric pressure to expose the above-mentioned artificial oxide film.

According to the above structure, in the film forming step, by using the self-assembled monolayer formed in the metal film forming area as a protective film for the metal film including the artificial oxide film, a film can be selectively formed only in the metal film non-forming area, thereby preventing the film from being formed on the artificial oxide film. Furthermore, by removing the self-assembled monolayer in the removing step, a substrate with a laminated structure in which the artificial oxide film and the film are exposed on the surface can be manufactured.

In the above configuration, it is preferred that the metal film is a copper film, and the artificial oxide film forming step is a step of oxidizing the surface of the copper film that has not been naturally oxidized to form a copper (II) oxide film.

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, the isoelectric point of the metal film formation area can be made uniform and raised compared to 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 film defects can be formed, which has excellent function as a protective film.

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

The substrate processing device of the present invention is designed to solve the above-mentioned problems. Its characteristics are as follows: it processes a substrate having a metal film forming area on the surface thereof and a metal film non-forming area on the surface thereof where the metal film is not formed, and comprises: an ultraviolet irradiation unit, which oxidizes the surface of the metal film that has not been naturally oxidized by irradiating ultraviolet rays under atmospheric pressure, thereby forming an artificial oxide film; a storage unit, which stores a processing liquid containing a material for forming a self-assembled monomolecular film; and a supply unit, which supplies the processing liquid to the surface of the substrate, thereby forming the self-assembled monomolecular film on the artificial oxide film in the metal film forming area.

According to the above structure, by providing an ultraviolet irradiation unit, the surface of the metal film can be oxidized by irradiating ultraviolet rays to a metal film that has not been naturally oxidized under atmospheric pressure, thereby forming an artificial oxide film. In addition, by supplying the processing liquid stored in the storage unit to the surface of the substrate after irradiation with ultraviolet rays through the supply unit, a self-assembled monomolecular film can be formed on the artificial oxide film. That is, if it is the above structure, a substrate processing device capable of forming the following self-assembled monomolecular film can be provided. Compared with the case where a self-assembled monomolecular film is formed on a metal film with a natural oxide film, the film density of the self-assembled monomolecular film is more uniform and higher, and the generation of film defects is also suppressed or reduced, and the function as a protective film is excellent.

In order to solve the above-mentioned problem, another substrate processing device of the present invention is characterized in that: it processes a substrate having a metal film forming area on its surface where a metal film is formed and a metal film non-forming area where the above-mentioned metal film is not formed, and comprises: an oxidizing processing liquid supply unit, which oxidizes the above-mentioned surface of the above-mentioned metal film that is not naturally oxidized by supplying an oxidizing processing liquid under atmospheric pressure, thereby forming an artificial oxide film; a storage unit, which stores a processing liquid containing a material for forming a self-assembled monomolecular film; and a supply unit, which supplies the above-mentioned processing liquid to the surface of the above-mentioned substrate, thereby forming the above-mentioned self-assembled monomolecular film on the above-mentioned artificial oxide film in the above-mentioned metal film forming area.

According to the above structure, by providing an oxidizing treatment liquid supply unit, the surface of the metal film can be oxidized by supplying the oxidizing treatment liquid to the metal film that is not naturally oxidized under atmospheric pressure, thereby forming an artificial oxide film. In addition, by supplying the treatment liquid stored in the storage unit to the surface of the substrate through the supply unit, a self-assembled monomolecular film can be formed on the artificial oxide film. That is, if it is the above structure, a substrate processing device capable of forming a self-assembled monomolecular film can be provided. Compared with the case where a self-assembled monomolecular film is formed on a metal film with a natural oxide film, the film density of the self-assembled monomolecular film is more uniform and higher, and the generation of film defects is also suppressed or reduced, and the function as a protective film is excellent. [Effect of the invention]

According to the present invention, since the molecules forming the self-assembled monomolecular film are adsorbed after forming an artificial oxide film on a metal film that has not been naturally oxidized, the molecules can be adsorbed at a high density and uniformly. As a result, a self-assembled monomolecular film with a high and uniform film density and suppressed or reduced film defects can be formed. That is, the present invention can provide a substrate processing method and substrate processing device that can selectively form a self-assembled monomolecular film with excellent function as a protective film.

(First embodiment) The following describes the substrate processing method and substrate processing device of the first embodiment of the present invention.

<Substrate processing method> Below, the substrate processing method of the present embodiment is first described with reference to FIGS. 1 to 3. FIG. 1 is a flow chart showing an example of the overall process of the substrate processing method of the first embodiment of the present invention. FIGS. 2A to 2D are schematic diagrams showing an example of the state change of the substrate in the substrate processing method of the embodiment of the present invention. FIG. 2A shows the removal of the natural oxide film formed on the surface of the metal film of the substrate, FIG. 2B shows the formation of an artificial oxide film on the surface of the metal film after the removal of the natural oxide film, FIG. 2C shows the supply of the forming material of the self-assembled monolayer to the surface of the substrate, and FIG. 2D shows the formation of a self-assembled monolayer in the metal film formation area on the surface of the substrate. In addition, FIG. 3A and FIG. 3B are schematic diagrams showing an example of the state change of the substrate in the substrate processing method of the embodiment of the present invention. FIG. 3A shows the situation where a film is formed in the metal film non-formation area on the substrate surface, and FIG. 3B shows the situation after the self-assembled monolayer film in the metal film formation area on the substrate surface is removed.

The substrate processing method of the present embodiment provides a technique for selectively forming a film according to the material of the substrate surface when forming a film on the surface of a substrate W. Furthermore, in this specification, "substrate" refers to various substrates such as semiconductor substrates, glass substrates for masks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FED (Field Emission Display), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks.

As shown in FIG. 1 , the substrate processing method of the present embodiment includes at least a substrate W preparation step S101, a natural 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 SAM removal step S106.

The substrate W prepared in the preparation step S101 of the substrate W includes a metal film forming region where a metal film 1 is formed, and a metal film non-forming region where an insulating film 2 is exposed, as shown in FIG. 1 and FIG. 2A. More specifically, the substrate W includes an insulating film 2 having a trench with an arbitrary wiring width formed therein, and a metal film 1 embedded in the trench. Furthermore, the preparation step of the substrate W may include, for example, using a substrate loading and unloading mechanism to carry the substrate W into a container for accommodating the substrate W, i.e., a chamber (described in detail below).

Although one metal film forming region and one metal film non-forming region are formed in FIG2A , a plurality of metal film non-forming regions may be formed. For example, a strip-shaped metal film non-forming region may be disposed between adjacent strip-shaped metal film forming regions, or a strip-shaped metal film forming region may be disposed between adjacent strip-shaped metal film non-forming regions.

In addition, the substrate W of the present embodiment is not limited to the case where only the metal film forming area and the metal film non-forming area are provided on its surface. For example, there may be an area where other films including materials different from the metal film 1 and the insulating film 2 are exposed and formed on the surface. In this case, the location of the area is not particularly limited and can be set arbitrarily.

The metal film 1 is not particularly limited, and examples thereof include those containing copper (Cu), tungsten (W), ruthenium (Ru), germanium (Ge), silicon (Si), titanium nitride (TiN), cobalt (Co), molybdenum (Mo), and the like.

A natural oxide film 3 exists on the surface of the metal film 1. The natural oxide film 3 is formed by the reaction between the metal constituting the metal film 1 and oxygen in the air to oxidize the surface of the metal film 1. For example, when the metal film 1 is a copper film, in addition to the copper film exposed on the surface, the metal film formation region also contains a copper oxide (I) film (Cu ₂ O film) and a copper oxide (II) film (CuO film) as natural oxide films. As a result, the metal film formation region has a surface state with uneven film quality such as isoelectric point.

The insulating film 2 is not particularly limited, and examples thereof include those containing silicon oxide (SiO ₂ ), helium oxide (HfO ₂ ), zirconium oxide (ZrO ₂ ), silicon nitride (SiN), and the like.

The natural oxide film removal step S102 is a step of removing the natural oxide film 3 formed on the metal film 1 as shown in FIG. 1 and FIG. 2A. As the natural oxide film removal step S102, for example, pickling in which an acidic solution is brought into contact with the natural oxide film can be cited. There is no particular limitation on the method of bringing the natural oxide film 3 into contact with the acidic solution. For example, a method of directly supplying the acidic solution to the substrate W for coating or a method of spraying, a method of immersing the substrate W in the acidic solution, etc. can be cited. As a method of applying the acidic solution to the surface of the substrate W, for example, a method of supplying the acidic solution to the center of the surface of the substrate W while rotating the substrate W at a certain speed with its center as an axis can be cited. Thus, the acid solution supplied to the surface of the substrate W flows from the center of the surface of the substrate W to the periphery of the substrate W due to the centrifugal force generated by the rotation of the substrate W, thereby spreading to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the acid solution to form a liquid film of the acid solution, thereby performing acid cleaning. In addition, the cleaning time for acid cleaning is not particularly limited and can be set as appropriate as needed.

As the acidic solution, inorganic acid and organic acid can be cited. The inorganic acid is not particularly limited, and examples thereof include sulfuric acid, hydrochloric acid, and hydrofluoric acid. Also, the organic acid is not particularly limited, and examples thereof include acetic acid and citric acid. The concentration of the acidic solution is not particularly limited, and can be set depending on the type or thickness of the natural oxide film, the cleaning time, and the like.

Furthermore, in the natural oxide film removal step S102, a pre-treatment cleaning may be performed before pickling with an acid solution. In this way, a neutral degreasing treatment for removing oil and the like attached to the substrate surface may be performed. The cleaning agent used for the pre-treatment cleaning is not particularly limited, and examples thereof include organic solvents such as acetone and ethanol. The pre-treatment cleaning method is also not particularly limited, and examples thereof include a method of directly supplying the cleaning agent to the substrate W for coating or spraying, a method of immersing the substrate W in the cleaning agent, and the like. As a method of applying the cleaning agent to the surface of the substrate W, similar to the case of pickling, a method can be cited in which the cleaning agent is supplied to the center of the surface of the substrate W while the substrate W is rotated at a certain speed with the center of the substrate W as the axis. Furthermore, the cleaning time as pre-treatment cleaning is not particularly limited and can be set as appropriate. In addition, water cleaning can be performed after pre-treatment cleaning and before pickling with an acid solution.

As shown in FIG. 1 and FIG. 2B , the ultraviolet irradiation step S103 is a step of irradiating the surface of the metal film 1 after the natural oxide film 3 is removed with ultraviolet rays (wavelength range: below 380 nm) under atmospheric pressure to oxidize the surface of the metal film 1 to form an artificial oxide film 4. By replacing the natural oxide film 3 with the artificial oxide film 4 in this way, the surface state of the metal film formation area that is uneven when the natural oxide film 3 exists, more specifically, the isoelectric point, etc., can be made uniform within the surface. For example, in the case where the metal film 1 is a copper film (isoelectric point: 7.7), the metal film formation area in the state where the natural oxide film 3 is formed on the surface of the copper film presents a surface state in which the exposed copper film and the CuO film (isoelectric point: 9.5) and the Cu ₂ O film as the natural oxide film are mixed. However, by irradiating the copper film after the natural oxide film 3 is removed with ultraviolet rays to oxidize the surface of the copper film, a CuO film (isoelectric point: 9.5) can be formed as the artificial oxide film 4. This can suppress the copper film from being exposed, and can also reduce the Cu ₂ O film. Therefore, the metal film forming area after the CuO film is formed on the surface of the copper film has a more uniform surface state than when the natural oxide film is formed on the surface of the copper film, and the isoelectric point can also be increased compared to the metal film forming area in the state where the copper film is exposed after the natural oxide film 3 is removed. In addition, in this specification, "under atmospheric pressure" refers to an environment of 0.7 atmospheres or more and 1.3 atmospheres or less with standard atmospheric pressure (1 atmosphere, 1013 hPa) as the center.

Furthermore, in the ultraviolet irradiation step S103, the ultraviolet irradiation may be performed while the substrate W is rotated at a constant speed about its center portion as an axis. In this way, the accumulated light amount of the irradiated ultraviolet light can be made uniform within the surface Wf of the substrate W.

Regarding the irradiation conditions of ultraviolet rays, the irradiation intensity is preferably in the range of 1 mW/ ^cm2 or more and 100 mW/ ^cm2 or less, more preferably in the range of 2.5 mW/ ^cm2 or more and 30 mW/ ^cm2 or less, and particularly preferably in the range of 5 mW/ ^cm2 or more and 15 mW/ ^cm2 or less. By setting the irradiation intensity of ultraviolet rays to 5 mW/ ^cm2 or more, the surface of the metal film 1 can be fully oxidized. On the other hand, by setting the irradiation intensity of ultraviolet rays to 15 mW/ ^cm2 or less, the film thickness of the artificial oxide film 4 can be prevented from becoming too thick. Furthermore, the irradiation time of ultraviolet rays 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 setting the irradiation time of ultraviolet light to be 0.08 hours or more, the surface of the metal film 1 can be fully oxidized. On the other hand, by setting the irradiation time of ultraviolet light to be 0.32 hours or less, the thickness of the artificial oxide film 4 can be prevented from becoming too thick. Furthermore, the peak wavelength of the irradiated ultraviolet light can be selected as appropriate depending on the light source used. For example, multiple peak wavelengths including 185 nm and 254 nm can be included.

The type of light source for emitting ultraviolet rays is not particularly limited, and may be either a linear light source or an electric light source. The irradiation position of the ultraviolet rays and the distance between the light source and the surface of the substrate W are not particularly limited, and may be set as appropriate. For example, it is preferable to set the irradiation intensity of the ultraviolet rays in a manner that is uniform within the surface of the substrate W relative to the irradiated substrate W, taking into account the area of the substrate W and the irradiation region.

As shown in FIG. 1 , FIG. 2C and FIG. 2D , the SAM forming step S104 is a step of forming a SAM 6 by making the processing liquid contact the surface of the substrate W, so that the SAM forming material 5 contained in the processing liquid is adsorbed on the surface of the artificial oxide film 4. Compared with the natural oxide film 3, the artificial oxide film 4 has a uniform surface state and a larger isoelectric point. Therefore, the SAM forming material 5 is different from the natural oxide film 3 and can be uniformly and densely adsorbed on the artificial oxide film 4. As a result, a SAM 6 with a uniform and high film density, in which the generation of film defects is suppressed or reduced, and which has an excellent function as a protective film can be formed.

The processing solution at least includes a material for forming a SAM (hereinafter referred to as "SAM forming material") and a solvent. The SAM forming material can be dissolved or dispersed in the solvent.

The SAM forming material is not particularly limited, and examples thereof include phosphonic acid compounds having a phosphonic acid group such as monophosphonic acid and diphosphonic acid. These phosphonic acid compounds may be used alone or in combination of two or more.

The monophosphonic acid is not particularly limited, and examples thereof 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 1 to 18 carbon atoms and having a fluorine atom; or a vinyl group). In addition, in the present specification, when a range of carbon numbers is indicated, the range is intended to include all integer carbon numbers contained in the range. Therefore, for example, an alkyl group having "1 to 3 carbon atoms" refers to all alkyl groups having 1, 2, and 3 carbon atoms.

The alkyl group having 1 to 18 carbon atoms may be either linear or branched. The carbon number of the alkyl group is preferably in the range of 3 to 18, more preferably in the range of 10 to 18. The alkyl group having 1 to 18 carbon atoms and having a fluorine atom may be either linear or branched. The carbon number of the alkyl group having a fluorine atom is preferably in the range of 3 to 18, more preferably in the range of 10 to 1.

Furthermore, as the monophosphonic acid represented by the above RP(=O)(OH) ₂ , specifically, for example, there can be mentioned compounds represented by any one of the following chemical formulas (1) to (16).

[Chemistry 1]

Furthermore, as the monophosphonic acid, in addition to the above-exemplified compounds, a compound represented by any of the following chemical formulas (17) to (19) can be used.

[Chemistry 2]

As the diphosphonic acid, there can be mentioned a compound represented by any of the following chemical formulas (20) and (21).

[Chemistry 3]

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

The solvent in the treatment solution is not particularly limited, and examples thereof include alcohol solvents, ether solvents, glycol ether solvents, glycol ester solvents, and the like. The alcohol solvent is not particularly limited, and examples thereof include ethanol, and the like. The ether solvent is not particularly limited, and examples thereof include tetrahydrofuran (THF), and the like. The glycol ether solvent is not particularly limited, and examples thereof include propylene glycol monomethyl ether (PGME), and the like. The glycol ester solvent is not particularly limited, and examples thereof include propylene glycol monomethyl ether acetate (PGMEA), and the like. These solvents may be used alone or as a mixture of two or more. Furthermore, these solvents may be used in any combination with the above-exemplified phosphonic acid compounds. Among the exemplified solvents, alcohol solvents are preferred from the viewpoint of being able to dissolve the phosphonic acid compound, and ethanol is particularly preferred.

The content of the SAM forming material relative to the total mass of the treatment solution is preferably in the range of 0.0004 mass % to 0.2 mass %, more preferably in the range of 0.004 mass % to 0.08 mass %, and particularly preferably in the range of 0.04 mass % to 0.06 mass %.

Furthermore, the treatment liquid may contain known additives within the range that does not hinder the effect of the present invention. The additives are not particularly limited, and examples thereof include stabilizers and surfactants.

SAM 6 is selectively formed only on the metal film 1 in the metal film forming area of the substrate W, and is not formed in the metal film non-forming area. The reason why SAM 6 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 group of the phosphonic acid compound as the SAM forming material 5 reacts with the -OH group on the surface of the Cu film as shown in the following chemical reaction formula.

[Chemistry 4]

The method for bringing the processing liquid into contact with the substrate W is not particularly limited, and examples thereof include a method of applying the processing liquid on the surface of the substrate W, a method of spraying the processing liquid onto the surface of the substrate W, a method of immersing the substrate W in the processing liquid, and the like.

As a method of applying the processing liquid to the surface of the substrate W, for example, there can be cited a method in which the processing liquid is supplied to the center of the surface of the substrate W while the substrate W is rotated at a certain speed about the center of the substrate W. In this way, the processing liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W to the peripheral portion of the substrate W due to the centrifugal force generated by the rotation of the substrate W, thereby diffusing to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the processing liquid, and a liquid film of the processing liquid is formed.

The SAM forming step 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 examples thereof include a step of heating the substrate W or a step of rotating the substrate W at a certain speed to remove the processing liquid by centrifugal force.

When the step of heating the substrate W is performed, 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 generally in the range of 0°C to 200°C, preferably 10°C to 150°C, and more preferably 20°C to 100°C. In addition, the heating time is not particularly limited as long as the processing liquid can be sufficiently vaporized and removed, but is generally 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.

Furthermore, when the step of using centrifugal force to remove the processing liquid is implemented, the rotation speed of the substrate W is not particularly limited as long as it can fully remove the processing liquid, but 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.

Furthermore, the step of removing the treatment liquid preferably includes a rinsing step of bringing the rinsing liquid into contact with the surface of the substrate W containing the residual treatment liquid. In this case, the step of removing the treatment liquid may include, for example, first performing a rinsing step and then performing the above-mentioned step of heating the substrate W. In this way, the treatment liquid on the surface Wf of the substrate W can be replaced with a rinsing liquid, and then the rinsing liquid can be removed by heating. Furthermore, the step of removing the treatment liquid may include performing the above-mentioned spin-drying step using centrifugal force after the rinsing step. In this case, the treatment liquid on the surface Wf of the substrate W can be replaced with a rinsing liquid, and then the rinsing liquid can be removed by spinning it off from the surface Wf of the substrate W using centrifugal force. By including a rinsing step in the step of removing the treatment liquid, the treatment liquid can be further prevented from remaining on the surface of the substrate W. In addition, the SAM can be further prevented from remaining on the surface of the substrate W (or the metal film non-formed region of the substrate W) and from precipitating. As a result, a film can be selectively formed on the metal film non-formed region (details will be described below).

The method for bringing the rinsing liquid into contact with the surface of the substrate W is not particularly limited, and examples thereof include a method of directly supplying the rinsing liquid onto the substrate W for coating, a method of spraying, and a method of immersing the substrate W in the rinsing liquid. As a method for coating the rinsing liquid on the surface of the substrate W, for example, a method of supplying the rinsing liquid to the center of the surface of the substrate W while rotating the substrate W at a certain speed with the center of the substrate W as an axis can be cited. In this way, the rinsing liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W to the periphery of the substrate W due to the centrifugal force generated by the rotation of the substrate W, thereby diffusing to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the rinsing liquid to form a liquid film of the rinsing liquid, thereby replacing the processing liquid with the rinsing liquid. In addition, the time for the rinsing step is not particularly limited and can be set as needed.

There is no particular limitation on the rinsing liquid, and for example, a solvent used in the treatment liquid can be used. More specifically, examples of the rinsing liquid include alcohol solvents, ether solvents, glycol ether solvents, glycol ester solvents, and the like. There is no particular limitation on the alcohol solvent, and for example, ethanol and the like can be mentioned. There is no particular limitation on the ether solvent, and for example, tetrahydrofuran (THF) and the like can be mentioned. There is no particular limitation on the glycol ether solvent, and for example, propylene glycol monomethyl ether (PGME) and the like can be mentioned. There is no particular limitation on the glycol ester solvent, and for example, propylene glycol monomethyl ether acetate (PGMEA) and the like can be mentioned. These rinsing liquids can be used alone or as a mixture of two or more.

Furthermore, a step of reducing the dissolved oxygen concentration in the treatment solution used in the SAM forming step S104 (dissolved oxygen concentration reducing step) may be performed in advance. This can reduce the oxidation of the metal film 1 and the dissolution of the metal in the treatment solution, thereby reducing the etching of the metal film 1.

The method for reducing the concentration of dissolved oxygen in the treatment liquid is not particularly limited, and examples thereof include a method of supplying an inert gas to the treatment liquid for bubbling, or a method of using a vacuum degassing device or an oxygen permeable membrane, etc. Examples of the inert gas include nitrogen (N ₂ ), helium (He), neon (Ne), and argon (Ar).

When the concentration of dissolved oxygen in the treatment liquid is reduced by bubbling with an inert gas, this step is preferably performed under an inert gas atmosphere. In this way, the concentration of dissolved oxygen in the treatment liquid can be further reduced. Furthermore, when the step is performed under an inert gas atmosphere, the oxygen concentration in the inert gas atmosphere is preferably less than 0.1%, more preferably less than 0.01%, and particularly preferably less than 0.001%. If the concentration of dissolved oxygen in the treatment liquid is reduced under an inert gas atmosphere in which the oxygen concentration does not reach 0.1%, the oxygen contained in the atmosphere can be prevented from dissolving in the treatment liquid, thereby further reducing the concentration of dissolved oxygen in the treatment liquid. Furthermore, as an inert gas, nitrogen ( _N2 ), helium (He), neon (Ne), argon (Ar), etc. can be used.

The dissolved oxygen concentration of the processing solution after the dissolved oxygen concentration reducing step (or just before the processing solution contacts the substrate W) is preferably less than 100 ppb, more preferably less than 10 ppb, and even more preferably less than 1 ppb.

The film forming step S105 is a step of forming a target film 7 on the insulating film 2 in the metal film non-forming area as shown in FIG. 1 and FIG. 3A. At this time, the SAM 6 formed in the metal film forming area plays a shielding function as a protective film of the metal film 1. The SAM 6 of this embodiment has an excellent protective function because the film density is high and uniform, and the generation of film defects is also suppressed or reduced. Therefore, the selective film formation of the film 7 in the metal film non-forming area can be well performed.

The target film 7 is not particularly limited, and examples thereof include films containing aluminum oxide (Al ₂ O ₃ ), cobalt oxide (CoO), or zirconium oxide (ZrO ₂ ). The method for forming the film 7 is not particularly limited, and examples thereof include CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), vacuum evaporation, sputtering, plating, thermal CVD, and thermal ALD.

As shown in FIG. 1 and FIG. 3B , the removal step S106 is a step of removing the SAM 6 formed in the metal film forming region after the step of forming the film 7 is performed. There is no particular limitation on the method of removing the SAM 6. For example, a method of directly removing the SAM 6 by dissolution or etching, a method of thinly peeling off the surface layer of the metal film 1 together with the SAM 6, etc. may be adopted.

For example, when removing SAM 6 containing a phosphonic acid compound, SAM 6 can be removed by bringing acetic acid into contact with SAM 6. Thus, as shown in FIG. 3B, a substrate W can be obtained in which a film 7 is selectively formed only in a metal film non-formation region and a metal film 1 is exposed.

Furthermore, when SAM 6 is removed by etching, for example, SAM 6 can be removed by contacting with oxygen-containing gas to vaporize SAM 6. The oxygen-containing gas is not particularly limited, and examples thereof include oxygen (O ₂ ) gas, ozone (O ₃ ) gas, etc. The oxygen-containing gas can be heated to a high temperature to promote chemical reaction. The oxygen-containing gas can also be plasma-formed to promote chemical reaction.

As described above, according to the substrate processing method of the present embodiment, by forming SAM 6 using a processing solution with a reduced dissolved oxygen concentration, the metal film 1 can be inhibited from being etched during the selective film formation process of the SAM 6 in the metal film formation area.

<Substrate processing device> Next, the substrate processing device of this embodiment is described below with reference to the drawings. The substrate processing device of this embodiment has at least a processing liquid supply device for supplying a processing liquid, an ultraviolet irradiation device for forming an artificial oxide film, a film forming device for forming a SAM6 film, and a control unit for controlling each unit of the substrate processing device.

[Processing liquid supply device] As shown in FIG. 4 , the processing liquid supply device 100 of this embodiment has the function of supplying the processing liquid to the film forming device 300, and has at least a processing liquid tank 11, a pressurizing unit 12, and a pipe 13. FIG. 4 is an explanatory diagram showing a schematic diagram of the processing liquid supply device 100 in the substrate processing device of this embodiment.

The treatment liquid tank 11 may include a stirring section for stirring the treatment liquid in the treatment liquid tank 11 and a temperature adjustment section for adjusting the temperature of the treatment liquid in the treatment liquid tank 11 (neither of which is shown in the figure). As the stirring section, there may be cited a rotating section for stirring the treatment liquid in the treatment liquid tank 11 and a stirring control section for controlling the rotation of the rotating section. The stirring control section is electrically connected to the control section 400, and the rotating section may include, for example, a spiral stirring wing at the lower end of the rotating shaft. The control section 400 rotates the rotating section by issuing an action command to the stirring control section, thereby stirring the treatment liquid with the stirring wing. As a result, the concentration and temperature of the treatment liquid in the treatment liquid tank 11 may be made uniform.

The pressurizing unit 12 includes a nitrogen supply source 16, which is a supply source of gas for pressurizing the treated liquid tank 11, a pump (not shown) for pressurizing the nitrogen, a nitrogen supply pipe 14, and a valve 15 provided in the middle of the path of the nitrogen supply pipe 14. The nitrogen supply source 16 is connected to the treated liquid tank 11 pipeline by the nitrogen supply pipe 14. An air pressure sensor (not shown) electrically connected to the control unit 400 may be provided in the treated liquid tank 11. In this case, the control unit 400 controls the operation of the pump based on the value detected by the air pressure sensor, and can maintain the air pressure in the treated liquid tank 11 at a specified air pressure higher than the atmospheric pressure. In addition, the valve 15 is also electrically connected to the control unit 400, so that the switch of the valve 15 can be controlled according to the action instructions of the control unit 400.

The pipe 13 is connected to the film forming device 300. A valve 13a is provided in the middle of the path of the pipe 13. The valve 13a is electrically connected to the control unit 400, and the opening and closing of the valve 13a can be controlled according to the action command of the control unit 400. When the valve 13a and the valve 15 are opened according to the action command of the control unit 400, the processing liquid is supplied (pressed) to the film forming device 300 through the pipe 13.

[Ultraviolet irradiation device] The ultraviolet irradiation device 200 is described based on FIG. 5 . FIG. 5 is an explanatory diagram showing the outline of the ultraviolet irradiation device 200 provided in the film forming device 300 .

The ultraviolet irradiation device 200 is arranged inside the film forming device 300 above the substrate holding portion (in the direction indicated by the arrow Z in FIG. 5 ) in such a manner that the surface Wf of the substrate W held on the substrate holding portion (to be described in detail below) can be irradiated with ultraviolet rays. The ultraviolet irradiation device 200 has at least a plurality of ultraviolet irradiation portions 21 and a quartz glass 22.

The ultraviolet irradiation part 21 shown in FIG. 5 is a linear light source, and is arranged so that its longitudinal direction is parallel to the direction shown by Y in FIG. 5 . Furthermore, each ultraviolet irradiation part 21 is arranged in a manner of being equally spaced from each other in the direction shown by the arrow X. However, the ultraviolet irradiation part of the present invention is not limited to this form. For example, it can also be a form in which annular ultraviolet irradiation parts with different diameters are arranged in a concentric circle shape. Furthermore, the ultraviolet irradiation part can also be a point light source. In this case, it is preferred that a plurality of ultraviolet irradiation parts are arranged so as to be equally spaced from each other within the plane.

The type of the ultraviolet irradiation unit 21 is not particularly limited, and for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an excimer lamp, a metal halide lamp, and a UV (ultraviolet)-LED (Light Emitting Diode) can be used. In addition, the plurality of ultraviolet irradiation units 21 may be of the same type or of different types. When a plurality of ultraviolet irradiation units 21 of different types are used, they may be configured so that the peak wavelength or light intensity is different from each other.

The quartz glass 22 is disposed between the ultraviolet irradiation part 21 and the substrate W. The quartz glass 22 is a plate-shaped body, and is arranged parallel to the horizontal direction. In addition, the quartz glass 22 has light transmittance, heat resistance, and corrosion resistance to ultraviolet rays, and can allow the ultraviolet rays irradiated from the ultraviolet irradiation part 21 to pass through and irradiate the surface Wf of the substrate W. Furthermore, the quartz glass 22 can protect the ultraviolet irradiation part 21 from the gas atmosphere in the chamber 50 (details will be described below).

[Film-forming device] Next, the film-forming device 300 will be described based on FIG. 6 . FIG. 6 is an explanatory diagram showing the outline of the film-forming device 300 provided in the substrate processing device. In addition, in FIG. 6 , the illustration of the ultraviolet irradiation device 200 shown in FIG. 5 is omitted.

The film forming device 300 of this embodiment is a single-chip film forming device capable of forming a SAM 6 in a metal film forming region where a metal film 1 is formed.

As shown in FIG6 , the film forming apparatus 300 includes at least a substrate holding portion 30 for holding a substrate W, a supply portion 40 for supplying a processing liquid to a surface Wf of the substrate W, a chamber 50 that is a container for accommodating the substrate W, and an anti-spatter shield 60 that captures the processing liquid. In addition, the film forming apparatus 300 may also include a loading and unloading mechanism (not shown) for loading and unloading the substrate W.

The substrate holding part 30 is a mechanism for holding the substrate W. As shown in FIG6 , the substrate W is held in a substantially horizontal position with the substrate surface Wf facing upward so that the substrate W can be rotated. The substrate holding part 30 has a rotating chuck 31 formed by integrally combining a rotating base 33 and a rotating spindle 34. The rotating base 33 has a substantially circular shape when viewed from above, and a hollow rotating spindle 34 extending in a substantially vertical direction is fixed to the center thereof. The rotating spindle 34 is connected to a rotating shaft of a chuck rotating mechanism 36 including a motor. The chuck rotating mechanism 36 is housed in a cylindrical outer shell 37, and the rotating spindle 34 is supported by the outer shell 37 so as to be freely rotatable around the rotating shaft in the vertical direction.

The chuck rotating mechanism 36 can rotate the rotating spindle 34 around the rotating axis J by being driven by the chuck driving unit (not shown) of the control unit 400. Thereby, the rotating base 33 mounted on the upper end of the rotating spindle 34 rotates around the rotating axis J. The control unit 400 can control the chuck rotating mechanism 36 via the chuck driving unit, thereby adjusting the rotating speed of the rotating base 33.

In addition, the rotating spindle 34 may also be provided with a lifting mechanism 38 as shown in FIG. 5 and FIG. 6. The lifting mechanism 38 is electrically connected to the control unit 400, and the rotating base 33 and the rotating spindle 34 are lifted and lowered in the vertical direction (the direction indicated by the arrow Z in FIG. 6) according to the action command from the control unit 400. In this way, the distance between the substrate W held by the substrate holding unit 30 and the ultraviolet irradiation device 200 can be adjusted. For example, when the substrate W is carried into or out of the film forming device 300, the rotating base 33 and the rotating spindle 34 are lowered according to the action command of the control unit 400, so that the ultraviolet irradiation device 200 and the substrate W are separated. On the other hand, when the surface Wf of the substrate W is irradiated with ultraviolet rays, the rotating base 33 and the rotating spindle 34 are raised according to the action command of the control unit 400, so that the substrate W is brought close to the ultraviolet irradiation device 200. The distance when the substrate W is brought close to the ultraviolet irradiation device 200 is not particularly limited, and can be set as appropriate according to the irradiation intensity and irradiation time of the ultraviolet rays. In addition, as the lifting mechanism 38, for example, a cylinder, a ball screw mechanism, or a single-axis stage can be used. Furthermore, the periphery of the lifting mechanism 38 can also be covered by a bellows.

A plurality of chuck pins 35 for holding the peripheral end of the substrate W are vertically provided near the peripheral portion of the rotating base 33. The number of chuck pins 35 is not particularly limited, but it is preferred to provide at least three chuck pins 35 so as to reliably hold the circular substrate W. In the present embodiment, three chuck pins 35 are arranged at equal intervals along the peripheral portion of the rotating base 33. Each chuck pin 35 includes a substrate support pin for supporting the peripheral portion of the substrate W from below, and a substrate holding pin for holding the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support pin.

The supply unit 40 is arranged above the substrate holding unit 30, and supplies the processing liquid supplied from the processing liquid supply device 100 to the surface Wf of the substrate W. The supply unit 40 has a nozzle 41 and an arm 42. The nozzle 41 is installed at the front end of the horizontally extended arm 42, and is arranged above the rotating base 33 when spraying the processing liquid. In addition, the supply unit 40 further has a supply unit lifting mechanism 43. The supply unit lifting mechanism 43 is connected to the arm 42.

The supply unit lifting mechanism 43 is electrically connected to the control unit 400, and can lift the supply unit 40 according to the action command from the control unit 400. In this way, the nozzle 41 of the supply unit 40 can be moved close to or away from the substrate W held by the substrate holding unit 30, thereby adjusting the separation distance between the nozzle 41 and the surface Wf of the substrate W.

Furthermore, when the substrate W is carried into or out of the film forming apparatus 300, the supply unit lifting mechanism 43 is actuated according to the operation command of the control unit 400, thereby raising the supply unit 40. In this way, the nozzle 41 can be separated from the surface Wf of the substrate W by a certain distance, so that the substrate W can be easily carried in or out.

The anti-spatter shield 60 is provided to surround the rotating base 33. The anti-spatter shield 60 is connected to a lifting drive mechanism (not shown) and can be lifted and lowered in the vertical direction. When the processing liquid is supplied to the surface Wf of the substrate W, the anti-spatter shield 60 is positioned at a predetermined position by the lifting drive mechanism, and surrounds the substrate W held by the chuck pins 35 from a lateral position. In this way, the processing liquid splashing from the substrate W or the rotating base 33 can be captured.

In the above description, the case where the film forming apparatus in the substrate processing apparatus of the present invention is a single-wafer type is used as an example for explanation. However, the substrate processing apparatus of the present invention is not limited to this form, and can also be applied to the case where the film forming apparatus is a batch type.

[Control Unit] The control unit 400 is electrically connected to each part of the substrate processing device to control the operation of each part. The control unit 400 is composed of a computer having an operation unit and a memory unit. As the operation unit, a CPU (Central Processing Unit) is used to perform various operations. In addition, the memory unit has a dedicated memory for reading substrate processing programs, namely ROM (Read Only Memory), a free read-write memory for storing various information, namely RAM (Random Access Memory), and a disk pre-stored with control software and data. The disk pre-stores substrate processing conditions including ultraviolet irradiation conditions when forming an artificial oxide film and SAM6 film forming conditions. The CPU reads the substrate processing conditions into the RAM and controls the various parts of the substrate processing device according to the contents.

(Second embodiment) The following describes the substrate processing method and substrate processing device of the second embodiment of the present invention.

<Substrate processing method> The substrate processing method of this embodiment is described below with reference to FIG. 7. FIG. 7 is a flow chart showing an example of the overall process of the substrate processing method of the second embodiment of the present invention.

The difference of the substrate processing method of this embodiment is that, as shown in FIG. 7 , an oxidative treatment liquid contact step S103′ is performed as an artificial oxide film forming step instead of the ultraviolet irradiation step S103. With this structure, in this embodiment, a self-assembled monomolecular film as a protective film can be selectively formed on the substrate with a uniform and high film density and with film defects suppressed or reduced. In addition, since the other steps are the same as those of the first embodiment, their detailed description is omitted.

The oxidizing treatment liquid contact step S103' is the same as the ultraviolet irradiation step S103, and is a step of forming an artificial oxide film 4 on the metal film 1 after the natural oxide film 3 is removed under atmospheric pressure. Specifically, the oxidizing treatment liquid is contacted with the metal film 1 after the natural oxide film 3 is removed to oxidize it, thereby forming the artificial oxide film 4. The contact method of the oxidizing treatment liquid is not particularly limited, and for example, a method of applying the oxidizing treatment liquid on the surface of the substrate W, a method of spraying the treatment liquid on the surface of the substrate W, a method of immersing the substrate W in the treatment liquid, etc. can be cited.

As a method of applying the oxidizing treatment liquid to the surface Wf of the substrate W, for example, there can be cited a method in which the oxidizing treatment liquid is supplied to the center of the surface of the substrate W while the substrate W is rotated at a certain speed about the center of the substrate W. In this way, the oxidizing treatment liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W to the peripheral portion of the substrate W due to the centrifugal force generated by the rotation of the substrate, and diffuses to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the oxidizing treatment liquid, and a liquid film of the oxidizing treatment liquid is formed.

The oxidizing treatment liquid is not particularly limited as long as it can form the artificial oxide film 4 on the surface of the metal film 1 after removing the natural oxide film 3. Examples of the oxidizing treatment liquid include ozone water and the like.

When ozone water is used as the oxidizing treatment liquid, the ozone concentration is preferably in the range of 1 ppm or more and 20 ppm or less, more preferably in the range of 5 ppm or more and 20 ppm or less, and particularly preferably in the range of 10 ppm or more and 20 ppm or less. By setting the concentration of ozone water to 10 ppm or more, the surface of the metal film 1 can be fully oxidized. On the other hand, by setting the concentration of ozone water to 20 ppm or less, the thickness of the artificial oxide film 4 can be prevented from becoming too thick.

The temperature of the oxidizing treatment liquid (more specifically, the liquid temperature before being supplied 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 treatment liquid to 20°C or higher, the surface of the metal film 1 can be fully oxidized. On the other hand, by setting the temperature of the oxidizing treatment liquid to 80°C or lower, the film thickness of the artificial oxide film 4 can be prevented from becoming too thick.

Furthermore, in the oxidizing treatment liquid contact step S103', a drying step of the residual oxidizing treatment liquid may be performed after the artificial oxide film is formed by the oxidizing treatment liquid contact and before the SAM forming step S104.

<Substrate processing device> Next, the substrate processing device of this embodiment is described below with reference to the drawings. The substrate processing device of the second embodiment has basically the same structure as the substrate processing device of the first embodiment, except that it has an oxidizing treatment liquid supply device instead of the ultraviolet irradiation device, and the substrate holding portion 30 does not have a lifting mechanism 38. In addition, the control unit of the second embodiment has the same structure as the control unit 400 of the first embodiment, except that it has the function of controlling the oxidizing treatment liquid supply device. In the following, as an oxidizing treatment liquid supply device, the case where the oxidizing treatment liquid is ozone water is used as an example for description. In addition, in the following, for those having the same functions as the substrate processing device of the first embodiment, the same symbols are attached and their descriptions are omitted.

[Oxidizing treatment liquid supply device] As shown in FIG8 and FIG9, the oxidizing treatment liquid supply device 500 has at least an oxidizing treatment liquid storage unit 70 and an oxidizing treatment liquid supply unit 80. FIG8 is an illustrative diagram showing a schematic diagram of the oxidizing treatment liquid storage unit 70 in the oxidizing treatment liquid supply device 500 of the present embodiment. FIG9 is an illustrative diagram showing a schematic diagram of the substrate processing device of the present embodiment.

As shown in FIG. 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 .

Ozone water as an oxidizing treatment liquid is stored in the oxidizing treatment liquid tank 71. The ozone water is produced by dissolving ozone gas supplied from an ozone gas supply unit 73 in pure water supplied from a pure water supply unit 72 in the oxidizing treatment liquid tank 71.

The pure water supply unit 72 includes a pure water supply source 75, a pure water supply pipe 76, and a valve 76a disposed in the middle of the path of the pure water supply pipe 76. The pure water supply source 75 is connected to the oxidizing treatment liquid tank 71 through the pure water supply pipe 76. The valve 76a is electrically connected to the control unit 400', and the opening and closing of the valve 76a can be controlled according to the action command of the control unit 400'. When the valve 76a is opened according to the action command of the control unit 400', pure water is pumped through the pure water supply pipe 76.

The ozone gas supply unit 73 includes an ozone gas supply source, i.e., an ozone gas supply source 77, an ozone gas supply pipe 78, and a valve 78a disposed in the middle of the path of the ozone gas supply pipe 78. The ozone gas supply source 77 is connected to the pipeline of the oxidizing treatment liquid tank 71 through 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 according to the action command of the control unit 400'. When the valve 78a is opened according to the action command of the control unit 400', the ozone gas is pumped through the ozone gas supply pipe 78. Furthermore, the amount of ozone gas supplied to the oxidizing treatment liquid tank 71 can be adjusted by the action command of the control unit 400', such as the opening time of the control valve 78a. Thus, the ozone concentration of the ozone water produced in the oxidizing treatment liquid tank 71 can be controlled by the control unit 400'.

The oxidizing treatment liquid supply pipe 74 is connected to the oxidizing treatment liquid tank 71 and the oxidizing treatment liquid supply part 80 (details will be described below). A valve 74a is provided in the middle of the path of the oxidizing treatment liquid supply pipe 74. The valve 74a is electrically connected to the control part 400' and can control the opening and closing of the valve 74a according to the action command of the control part 400'. When the valve 74a is opened according to the action command of the control part 400', the ozone water stored in the oxidizing treatment liquid tank 71 can be supplied to the oxidizing treatment liquid supply part 80.

As shown in FIG9 , the oxidizing treatment liquid supply unit 80 is arranged above the substrate holding unit 30, and supplies the treatment liquid from the oxidizing treatment liquid tank 71 of the oxidizing treatment liquid storage unit 70 to the surface Wf of the substrate W. The oxidizing treatment liquid supply unit 80 has a nozzle 81 and an arm 82. The nozzle 81 is mounted on the front end of the horizontally extended arm 82, and is arranged above the rotating base 33 when spraying the treatment liquid (in the direction indicated by the arrow Z in FIG9 ). In addition, the oxidizing treatment liquid supply unit 80 further has an oxidizing treatment liquid supply unit lifting mechanism 83. The oxidizing treatment liquid supply unit lifting mechanism 83 is connected to the arm 82.

The oxidizing treatment liquid supply unit lifting mechanism 83 is electrically connected to the control unit 400', and can lift the oxidizing treatment liquid supply unit 80 in the up and down direction (the direction indicated by the arrow Z in FIG. 9 ) according to the action command from the control unit 400'. In this way, the nozzle 81 of the oxidizing treatment liquid supply unit 80 can be moved closer to or farther from the substrate W held by the substrate holding unit 30, thereby adjusting the separation distance between the nozzle 81 and the surface Wf of the substrate W.

Furthermore, when the substrate W is carried into or out of the film forming apparatus 300, the oxidizing treatment liquid supply unit lifting mechanism 83 is actuated according to the operation command of the control unit 400', thereby raising the oxidizing treatment liquid supply unit 80. In this way, the nozzle 81 can be separated from the surface Wf of the substrate W by a certain distance, so that the substrate W can be easily carried in or out.

[Control Unit] The control unit 400' is electrically connected to each part of the substrate processing device to control the operation of each part. The control unit 400' is the same as the control unit 400 of the first embodiment, and is composed of a computer having an operation unit and a memory unit. The hardware structure of the operation unit and the memory unit is the same as that of the first embodiment. In addition, the memory unit (disk) pre-stores substrate processing conditions including the concentration of the oxidizing treatment liquid (the ozone concentration when the oxidizing treatment liquid is ozone water) and the temperature for forming an artificial oxide film, and the film forming conditions of SAM6. The CPU reads the substrate processing conditions into the RAM and controls each part of the substrate processing device according to the content.

(Other matters) The processing liquid supply device, ultraviolet irradiation device and oxidative processing liquid supply device described in each embodiment can be used in various devices other than the substrate processing device, or can also be used alone. In the above description, the best embodiment of the present invention is described. However, the present invention is not limited to this embodiment. The various components in the above embodiment and various variations can be changed, modified, replaced, added, deleted and combined within the scope of non-contradiction. [Example]

The following is a detailed description of preferred embodiments of the present invention. However, unless otherwise specified, the materials, blending amounts, conditions, etc. described in the embodiments do not limit the scope of the present invention.

(Example 1) [Substrate preparation step] First, prepare a substrate having a Cu film (film thickness 100 nm, metal film formation area) formed on the surface as a metal film.

[Natural oxide film removal step] Next, remove the natural oxide film formed on the surface of the Cu film of the substrate. Specifically, first, immerse the substrate in acetone for 10 minutes to remove the oil on the surface of the substrate. Then, immerse the substrate 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.

[Artificial oxide film formation step] Next, an artificial oxide film is formed on the Cu film after the natural oxide film is removed. Specifically, the substrate is transported to a chamber as shown in FIG5 , and ultraviolet irradiation is performed using an ultraviolet irradiation device. Thereby, a CuO film as an artificial oxide film is formed on the surface of the Cu film. Furthermore, the ultraviolet irradiation conditions are as follows. Light source of the ultraviolet irradiation part: low-pressure mercury lamp (trade name: EUV200WS-51, manufactured by SEN Special Light Source (Co., Ltd.)) Peak wavelength of ultraviolet light: 185 nm, 254 nm Ultraviolet irradiation intensity: 10 mW/cm ² Ultraviolet irradiation time: 0.16 hours Pressure in the chamber: atmospheric pressure Temperature in the chamber: 25°C Gas atmosphere in the chamber: air

[Formation of SAM and Al ₂ O ₃ Film] Octadecylphosphonic acid (CH ₃ (CH ₂ ) ₁₇ P(=O)(OH) ₂ ) as a SAM forming material was dissolved in an ethanol solvent to prepare a treatment solution. The concentration of octadecylphosphonic acid was 0.05 mass % relative to the total mass of the treatment solution.

Next, a treatment liquid is used to form a SAM on the surface of the substrate after the artificial oxide film is formed. Specifically, a film forming device as shown in FIG6 is used to apply a treatment liquid on the surface of the substrate to form a SAM formed by adsorbing octadecylphosphonic acid on the Cu film.

Furthermore, an Al ₂ O ₃ film was formed on the surface of the substrate. Specifically, an atomic layer deposition apparatus (trade name: SUNALE-R, manufactured by PICOSUN Co., Ltd.) was used to form the Al ₂ O ₃ film by the ALD method.

[Removal of SAM] Next, the SAM was removed from the substrate on which the Al ₂ O ₃ film was formed. Specifically, the substrate was immersed in acetic acid (concentration 100 mass %) with ultrasonic vibration, and the SAM was dissolved in the acetic acid and removed. In this way, a substrate was prepared in which a CuO film as an artificial oxide film was formed on the Cu film.

(Comparative Example 1) In this comparative example, SAM _{and Al2O3} films were formed without forming an artificial oxide film on the Cu film after removing the natural oxide film. Except for this, the same steps as in Example 1 were performed to produce a substrate having a natural oxide film formed on the Cu film.

(Evaluation of surface state) For the untreated substrate before the natural oxide film was removed, and each substrate of Example 1 and Comparative Example 1, the surface state on the Cu film was analyzed for evaluation. Specifically, the state of the Cu film surface was analyzed using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The results are shown in Figures 10A and 10B. Figure 10A shows a graph showing the X-ray photoelectron spectrum on the Cu film, and Figure 10B shows a graph showing the Auger electron spectrum on the Cu film.

As shown in Figures 10A and 10B, in the untreated substrate, the intrinsic bonding energy and kinetic energy values of Cu atoms, Cu ₂ O, and CuO show peaks on the Cu film. This confirms that on the Cu film of the untreated substrate, the exposed Cu film, Cu ₂ O film, and CuO film are mixed, forming a natural oxide film with uneven film quality.

In the substrate of Comparative Example 1, the intrinsic bonding energy value and kinetic energy value of Cu atoms on the Cu film showed the strongest peaks. It was confirmed that the natural oxide film had been removed from the surface of the Cu film in the substrate of Comparative Example 1. On the other hand, in the substrate of Example 1, the intrinsic bonding energy value and kinetic energy value of CuO showed stronger main peaks and satellite peaks. It was confirmed that the CuO film as an artificial oxide film was formed on the surface of the Cu film in the substrate of Example 1.

(Performance Evaluation of SAM) Next, the performance of SAM as a protective film was evaluated for each substrate of Example 1 and Comparative Example 1. Specifically, in the above-mentioned measurement using XPS X-ray photoelectron spectroscopy, the peak areas of the measurement peaks of the 2p _3/2 orbit of Cu atoms and the 2s orbit of Al atoms were obtained, and then the sensitivity coefficient was corrected to calculate the corrected peak areas of each measurement peak of Cu atoms and Al atoms. Using the obtained surface atomic concentrations of Cu atoms and Al atoms, the atomic number ratio (Al/(Al+Cu)) was calculated using the following formula. Atomic ratio (Al/(Al+Cu)) = (Al atomic concentration based on the peak area of the spectrum of the 2s track of Al atoms in XPS analysis)/((Al atomic concentration based on the peak area of the spectrum of the 2s track of Al atoms in XPS analysis) + (Cu atomic concentration based on the peak area of the spectrum of the 2p _3/2 track of Cu atoms in XPS analysis)) The result is shown in FIG11. FIG11 is a graph comparing the atomic ratio (Al/(Al+Cu)) of each substrate of Example 1 and Comparative Example 1.

As shown in Figure 11, in the substrate of Comparative Example 1 where SAM is formed on the natural oxide film of Cu film without forming an artificial oxide film, it is confirmed that the atomic number ratio on the Cu film is 0.44, and the existence ratio of Al atoms is high. Therefore, in Comparative Example 1 where SAM is formed on the natural oxide film of Cu film, the function of the Al ₂ O ₃ film as a protective film when it is formed is not sufficient.

On the other hand, in the substrate of Example 1 in which SAM was formed on a CuO film as an artificial oxide film, it was confirmed that the atomic number ratio on the Cu film was reduced to 0.03, and the existence ratio of Al atoms was fully suppressed. It was thus confirmed that in Example 1, by forming SAM on the CuO film, the function of SAM as a protective film can be greatly improved compared to the case where SAM is formed on the Cu film in a state where the natural oxide film has been removed. The reason is presumed to be that when SAM is formed on the CuO film, the film density of SAM can be increased and the defects of the film can be fully suppressed.

1: Metal film 2: Insulating film 3: Natural oxide film 4: Artificial oxide film 5: SAM forming material (self-assembled monomolecular film forming material) 6: SAM (self-assembled monomolecular film) 11: Processing liquid tank 12: Pressurizing unit 13: Piping 13a: Valve 14: Nitrogen supply pipe 15: Valve 16: Nitrogen supply source 21: Ultraviolet irradiation unit 22: Quartz glass 30: Substrate holding unit 40: Supply unit 41: Nozzle 42: Arm 43: Supply unit lifting mechanism 50: Chamber 60: Anti-splash shield 70: Oxidizing treatment liquid storage unit 71: Oxidizing treatment liquid tank 72: Pure water supply unit 73: Ozone gas supply unit 74: Oxidizing treatment liquid supply pipe 75: Pure water supply source 76: Pure water supply pipe 77: Ozone gas supply source 78: Ozone gas supply pipe 80: Oxidizing treatment liquid supply unit 81: Nozzle 82: Arm 83: Oxidizing treatment liquid supply unit lifting mechanism 100: Treatment liquid supply device 200: Ultraviolet irradiation device 300: Film forming device 400, 400': Control unit 500: Oxidizing treatment liquid supply device S101: Preparation step S102: Natural oxide film removal step S103: Ultraviolet irradiation step (artificial oxide film formation step) S103': Oxidative treatment liquid contact step (artificial oxide film formation step) S104: SAM (self-assembled monolayer) formation step S105: Film formation step S106: Removal step W: Substrate Wf: Surface of substrate

FIG. 1 is a flow chart showing an example of the overall process of the substrate processing method of the embodiment of the present invention. FIG. 2A shows the removal of the natural oxide film formed on the surface of the metal film of the substrate. FIG. 2B shows the formation of an artificial oxide film on the surface of the metal film after the removal of the natural oxide film. FIG. 2C shows the supply of the material for forming a self-assembled monolayer to the surface of the substrate. FIG. 2D shows the formation of a self-assembled monolayer in the metal film forming area on the surface of the substrate. FIG. 3A shows the formation of a film in the metal film non-forming area on the surface of the substrate. FIG. 3B shows the removal of the self-assembled monolayer in the metal film forming area on the surface of the substrate. FIG. 4 is a schematic diagram showing the processing liquid supply device provided in the substrate processing device of the embodiment of the present invention. FIG. 5 is an explanatory diagram showing the outline of the ultraviolet irradiation device provided in the substrate processing apparatus of the embodiment of the present invention. FIG. 6 is an explanatory diagram showing the outline of the film forming device provided in the substrate processing apparatus of the embodiment of the present invention. FIG. 7 is a flow chart showing an example of the overall process of the substrate processing method of another embodiment of the present invention. FIG. 8 is an explanatory diagram showing the outline of the oxidizing treatment liquid storage unit provided in the oxidizing treatment liquid supply device of another embodiment of the present invention. FIG. 9 is an explanatory diagram showing the outline of the film forming device provided in the substrate processing apparatus of another embodiment of the present invention. FIG. 10A shows a diagram showing an X-ray photoelectron spectrum of the Cu film surface. FIG. 10B shows a diagram showing an Orger electron spectrum of the Cu film surface. FIG. 11 is a graph comparing the atomic ratio (Al/(Al+Cu)) of each substrate in Example 1 and Comparative Example 1.

S101: Preparation steps

S102: Natural oxide film removal step

S103: UV irradiation step (artificial oxide film formation step)

S104: SAM (self-assembled monolayer) formation step

S105: Membrane formation step

S106: Removal step

Claims (11)

A substrate processing method is to process a substrate having a metal film forming region on the surface of which a metal film is formed and a metal film non-forming region on which the metal film is not formed, and comprises: an artificial oxide film forming step, which is to oxidize the non-naturally oxidized surface of the metal film under atmospheric pressure to form an artificial oxide film; and a self-assembled monomolecular film forming step, which is to form the self-assembled monomolecular film on the artificial oxide film by allowing a processing liquid containing a material for forming the self-assembled monomolecular film to contact at least the surface of the substrate. A substrate processing method as claimed in claim 1, wherein the artificial oxide film forming step is a step of irradiating ultraviolet rays on the surface of the metal film that has not been naturally oxidized. A substrate processing method as claimed in claim 1, wherein the artificial oxide film forming step is a step of allowing an oxidizing treatment liquid to contact the surface of the metal film which has not been naturally oxidized. A substrate processing method as claimed in claim 1, wherein the artificial oxide film forming step is the following step: oxidizing the surface of the metal film that has not been naturally oxidized to form the artificial oxide film, thereby making the isoelectric point of the metal film forming area more uniform and higher within the surface compared to before the artificial oxide film is formed. The substrate processing method of claim 1 includes a natural oxide film removal step of removing the natural oxide film formed on the surface of the metal film before the artificial oxide film formation step. A substrate processing method as claimed in claim 5, wherein the natural oxide film removal step is a step of removing the natural oxide film by bringing an acidic solution into contact with the natural oxide film. The substrate processing method of claim 1 further comprises: a film forming step, which is to selectively form a film in the metal film non-forming area by using the self-assembled monomolecular film formed in the metal film forming area as a protective film after the self-assembled monomolecular film forming step; and a removal step, which is to remove the self-assembled monomolecular film formed in the metal film forming area under atmospheric pressure after the film forming step to expose the artificial oxide film. The substrate processing method of claim 1, wherein the metal film is a copper film, and the artificial oxide film forming step is a step of oxidizing the surface of the copper film that has not been naturally oxidized to form a copper (II) oxide film. A substrate processing method as claimed in claim 1, wherein the processing solution comprises a phosphonic acid compound having a phosphonic acid group adsorbed on the surface of the metal film, and a solvent. A substrate processing device processes a substrate having a metal film forming region on the surface thereof and a metal film non-forming region on the surface thereof, and comprises: an ultraviolet irradiation unit, which irradiates the non-naturally oxidized surface of the metal film with ultraviolet rays under atmospheric pressure to oxidize the surface, thereby forming an artificial oxide film; a storage unit, which stores a processing liquid containing a material for forming a self-assembled monomolecular film; and a supply unit, which supplies the processing liquid to the surface of the substrate, thereby forming the self-assembled monomolecular film on the artificial oxide film in the metal film forming region. A substrate processing device processes a substrate having a metal film forming region on the surface thereof and a metal film non-forming region on the surface thereof, and comprises: an oxidizing treatment liquid supply unit, which supplies an oxidizing treatment liquid to the non-naturally oxidized surface of the metal film under atmospheric pressure to oxidize the surface to form an artificial oxide film; a storage unit, which stores a treatment liquid containing a material for forming a self-assembled monomolecular film; and a supply unit, which supplies the treatment liquid to the surface of the substrate to form the self-assembled monomolecular film on the artificial oxide film in the metal film forming region.