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 as a protective film while suppressing etching of a metal film on a substrate.SOLUTION: A substrate processing method according to the present invention is 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 method includes: a dissolved oxygen concentration reduction step for reducing the dissolved oxygen concentration of a processing liquid containing a material for forming a self-assembled monolayer 4; and a self-assembled monolayer formation step for forming the self-assembled monolayer 4 on the metal film 1 in the metal film formed region while suppressing oxidation of the metal film 1, by at least bringing the processing liquid after the dissolved oxygen concentration reduction step into contact with the surface of the substrate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus that are capable of performing selective film formation in an excellent manner. [Background technology]

[0002] In the manufacture of semiconductor devices, photolithography is widely used as a technique for selectively forming films on specific surface regions of a substrate. For example, after forming lower-layer wiring, an insulating film is deposited, and then photolithography and etching are used to form a dual damascene structure with trenches and via holes, and a conductive film such as Cu is filled into the trenches and via holes to form wiring.

[0003] However, in recent years, as semiconductor devices have become increasingly miniaturized, the alignment accuracy of photolithography has become insufficient, and therefore there is a demand for an alternative method to photolithography that can selectively form films in specific regions on the substrate surface with high precision.

[0004] For example, Patent Document 1 discloses a film formation method in which a self-assembled monolayer (SAM) is formed on the surface of a substrate region where film formation is not desired, and a film is selectively formed on a substrate region where no SAM is formed. According to this film formation method, by using a solvent with an optimal dielectric constant as a treatment solution for forming the SAM, more specifically a mixed solvent consisting of propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA), it is possible to suppress a decrease in the coverage of the SAM and prevent a decrease in the selectivity of the treatment solution for the metal film.

[0005] However, the film formation method disclosed in Patent Document 1 has a problem in that, for example, when a SAM is formed on a metal film made of copper, the metal film is etched. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 10,867,850 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a substrate processing method and a substrate processing apparatus that are capable of selectively forming a self-assembled monolayer as a protective film while suppressing etching of a metal film on a substrate. [Means for solving the problem]

[0008] The present invention was conceived based on the finding that etching of a metal film when forming a self-assembled monolayer (SAM) on a metal film-forming region of a substrate surface is caused by the dissolved oxygen concentration in the treatment solution used to form the SAM. That is, the present invention was made based on the finding that if the dissolved oxygen concentration in the treatment solution is too high, the dissolved oxygen oxidizes the metal film, causing the metal constituting the metal film to dissolve in the treatment solution, which can result in etching of the metal film.

[0009] In order to solve the above-mentioned problems, the substrate processing method according to the present invention is a substrate processing method for processing a substrate having, on its surface, 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, and is characterized by comprising: a dissolved oxygen concentration reduction step of reducing the dissolved oxygen concentration in a processing solution containing a material for forming a self-assembled monolayer; and a self-assembled monolayer formation step of bringing the processing solution after the dissolved oxygen concentration reduction step into contact with at least the surface of the substrate, thereby forming the self-assembled monolayer on the metal film in the metal film-formation region while suppressing oxidation of the metal film.

[0010] According to the above-described configuration, a treatment solution for forming a self-assembled monolayer on a metal film is used in which the dissolved oxygen concentration has been reduced in advance. This reduces the possibility of the metal film being oxidized and the metal constituting the metal film being dissolved in the treatment solution when the dissolved oxygen in the treatment solution comes into contact with the metal film. As a result, a self-assembled monolayer can be formed on the metal film while suppressing or reducing etching of the metal film.

[0011] In the above-described configuration, the dissolved oxygen concentration reduction step can reduce the dissolved oxygen concentration of the treatment solution by bubbling an inert gas into the treatment solution. In this method for reducing the dissolved oxygen concentration of the treatment solution, the degree of reduction of the dissolved oxygen concentration in the treatment solution can be easily controlled by, for example, adjusting the supply amount and supply time of the inert gas.

[0012] In the above-described configuration, the dissolved oxygen concentration reducing step is preferably carried out in an inert gas atmosphere, which makes it possible to reduce the dissolved oxygen concentration in the treatment solution while suppressing an increase in the dissolved oxygen concentration due to contact of the treatment solution with oxygen in the air.

[0013] In the above-described configuration, the self-assembled monolayer formation step is preferably performed in an atmosphere in which the dissolved oxygen concentration of the treatment solution after the dissolved oxygen concentration has been reduced is maintained or reduced. This allows the self-assembled monolayer to be formed on the metal film while suppressing an increase in the dissolved oxygen concentration due to contact of the treatment solution with oxygen in the air in contact with the metal film. As a result, etching of the metal film can be further prevented during the formation of the self-assembled monolayer.

[0014] In the above-described configuration, the dissolved oxygen concentration of the treatment solution after the dissolved oxygen concentration reducing step is preferably less than 100 ppb, which can further prevent the metal film from being etched when the self-assembled monolayer is formed.

[0015] In the above-described configuration, the treatment liquid may contain a phosphonic acid compound having a phosphonic acid group that is adsorbed to the surface of the metal film, and a solvent.

[0016] The above-described configuration may further include a film formation step, after the self-assembled monolayer formation step, of selectively forming a film in the metal film non-formation region using the self-assembled monolayer formed in the metal film formation region as a protective film, and a removal step, after the film formation step, of removing the self-assembled monolayer formed in the metal film formation region to expose the metal film.

[0017] According to the above-mentioned configuration, in the film formation step, the self-assembled monolayer formed in the metal film formation region serves as a protective film for the metal film, thereby selectively forming a film only in the metal film non-formation region and preventing a film from being formed on the metal film.Furthermore, by removing the self-assembled monolayer in the removal step, a substrate with a layered structure in which the metal film and the film are exposed on the surface can be produced.

[0018] In order to solve the above-mentioned problems, the substrate processing apparatus of the present invention is a substrate processing apparatus for processing a substrate having, on its surface, 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, and is characterized by comprising: a storage section for storing a processing liquid containing a material for forming a self-assembled monolayer; a first inert gas supply section for supplying an inert gas into the processing liquid stored in the storage section to reduce the dissolved oxygen concentration of the processing liquid; and a supply section for supplying the processing liquid after the dissolved oxygen concentration has been reduced to the surface of the substrate to form the self-assembled monolayer on the metal film in the metal film formation region while suppressing oxidation of the metal film.

[0019] According to the above configuration, a treatment liquid containing materials for forming a self-assembled monolayer is stored in a storage unit, and a first inert gas supply unit supplies an inert gas into the treatment liquid to preliminarily reduce the dissolved oxygen concentration in the treatment liquid. Then, when forming a self-assembled monolayer on a metal film in a metal film formation region of the substrate, the supply unit supplies the treatment liquid, the dissolved oxygen concentration of which has been preliminarily reduced, to the surface of the substrate. This reduces the risk of the metal film being oxidized and the metal constituting the metal film being dissolved in the treatment liquid when the dissolved oxygen in the treatment liquid comes into contact with the metal film. As a result, a substrate processing apparatus can be provided that can form a self-assembled monolayer while suppressing or reducing etching of the metal film.

[0020] In order to solve the above-mentioned problems, the present invention provides a substrate processing apparatus that collectively processes a plurality of substrates each having, on its surface, a metal film-forming region where a metal film is formed and a metal film-non-forming region where the metal film is not formed, and is characterized by comprising: a storage section that stores a processing liquid containing a material for forming a self-assembled monolayer; a first inert gas supply section that supplies an inert gas into the processing liquid stored in the storage section to reduce the dissolved oxygen concentration of the processing liquid; a liquid delivery section that delivers the processing liquid after the dissolved oxygen concentration has been reduced downstream from the storage section; and a processing tank that stores the processing liquid after the dissolved oxygen concentration has been reduced, delivered by the liquid delivery section, and immerses the plurality of substrates collectively in the processing liquid to form the self-assembled monolayer on the metal film in the metal film-forming region on the surface of each substrate while suppressing oxidation of the metal film.

[0021] According to the above configuration, a treatment liquid containing materials for forming a self-assembled monolayer is stored in a storage unit, and a first inert gas supply unit supplies an inert gas into the treatment liquid, thereby reducing the dissolved oxygen concentration in the treatment liquid in advance. When forming a self-assembled monolayer on a metal film in a metal film formation region of a substrate, a treatment tank stores a treatment liquid with a reduced dissolved oxygen concentration in advance, and multiple substrates are immersed in the treatment liquid at once. This reduces the risk of the metal film being oxidized and the metal constituting the metal film being dissolved in the treatment liquid when the dissolved oxygen in the treatment liquid comes into contact with the metal film. As a result, a substrate treatment apparatus can be provided that can form a self-assembled monolayer while suppressing or reducing etching of the metal film.

[0022] In the above configuration, it is preferable that the first inert gas supply unit supplies the inert gas into the inside of the storage unit to create an inert gas atmosphere inside the storage unit, and also supplies the inert gas into the treatment liquid stored in the storage unit to reduce the dissolved oxygen concentration of the treatment liquid.

[0023] According to the above configuration, the first inert gas supply unit creates an inert gas atmosphere inside the storage unit, thereby reducing the dissolved oxygen concentration in the treatment liquid while suppressing an increase in the dissolved oxygen concentration due to the treatment liquid coming into contact with oxygen in the air.

[0024] In the above configuration, the supply unit may further include an opposing member that faces the surface of the substrate at a given distance and is close to the surface of the substrate, and a second inert gas supply unit that supplies an inert gas toward a space between the surface of the substrate and the opposing member, wherein the second inert gas supply unit supplies the inert gas toward the space, thereby creating an atmosphere in which the dissolved oxygen concentration of the treatment liquid after the dissolved oxygen concentration reduction is maintained or reduced, and the supply unit may supply the treatment liquid after the dissolved oxygen concentration reduction to the surface of the substrate in an atmosphere in which the dissolved oxygen concentration of the treatment liquid is maintained or reduced.

[0025] According to the above configuration, the supply unit includes a facing member that can be positioned close to and facing the substrate surface at a desired distance, thereby forming a space between the substrate surface and the facing member. Furthermore, the supply unit includes a second inert gas supply unit that can supply an inert gas toward this space, thereby replacing the air in the space with an inert gas. This allows the supply unit to supply a treatment solution to the substrate surface to form a self-assembled monolayer on the metal film in an atmosphere that maintains or reduces the dissolved oxygen concentration of the treatment solution. This enables the formation of a self-assembled monolayer while suppressing an increase in the dissolved oxygen concentration due to contact of the treatment solution with oxygen in the air. As a result, a substrate processing apparatus can be provided that can further prevent etching of the metal film during self-assembled monolayer formation.

[0026] The above configuration may further include a chamber for supplying the processing liquid to the surface of the substrate by the supply unit within a sealed space, a third inert gas supply unit for supplying an inert gas into the chamber, and a pressure reduction unit for exhausting gas within the chamber, wherein the third inert gas supply unit supplies the inert gas into the chamber and the pressure reduction unit exhausts the gas within the chamber, thereby creating an atmosphere within the chamber in which the dissolved oxygen concentration of the processing liquid after the dissolved oxygen concentration reduction is maintained or reduced, and the supply unit may supply the processing liquid after the dissolved oxygen concentration reduction to the surface of the substrate in an atmosphere in which the dissolved oxygen concentration of the processing liquid is maintained or reduced.

[0027] According to the above configuration, the provision of a chamber allows the supply unit to supply the processing liquid to the substrate surface within a sealed space. Furthermore, the provision of a third inert gas supply unit that supplies an inert gas into the chamber and a pressure reduction unit that exhausts the gas within the chamber allows the air in the chamber to be replaced with an inert gas. This allows the supply unit to supply the processing liquid to the substrate surface to form a self-assembled monolayer on the metal film in an atmosphere that maintains or reduces the dissolved oxygen concentration of the processing liquid. This enables the formation of a self-assembled monolayer while suppressing an increase in the dissolved oxygen concentration due to contact of the processing liquid with oxygen in the air. As a result, a substrate processing apparatus can be provided that can further prevent etching of the metal film during self-assembled monolayer formation.

[0028] Furthermore, in the above-described configuration, it is preferable to further include a control unit that controls the first inert gas supply unit so that the dissolved oxygen concentration of the treatment solution after the dissolved oxygen concentration reduction is less than 100 ppb, thereby further suppressing etching of the metal film when forming a self-assembled monolayer. [Effects of the Invention]

[0029] According to the present invention, it is possible to provide a substrate processing method and a substrate processing apparatus that are capable of selectively forming a self-assembled monolayer as a protective film while suppressing etching of a metal film on a substrate. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a flowchart showing an example of an overall flow of a substrate processing method according to an embodiment of the present invention. [Figure 2]1A and 1B are schematic diagrams showing an example of changes in the state of a substrate in a film formation method according to an embodiment of the present invention, in which FIG. 1A shows the state in which a material for forming a self-assembled monolayer is supplied to the surface of the substrate, FIG. 1B shows the state in which a self-assembled monolayer is formed in a metal film formation region of the substrate surface, FIG. 1C shows the state in which a film is formed in a metal film non-formation region of the substrate surface, and FIG. 1D shows the state in which the self-assembled monolayer is removed from the metal film formation region of the substrate surface. [Figure 3] 1 is an explanatory diagram illustrating an outline of a main part of a substrate processing apparatus according to an embodiment of the present invention; [Figure 4] 1 is an explanatory diagram illustrating an outline of a single-wafer type film forming apparatus provided in a substrate processing apparatus according to an embodiment of the present invention. [Figure 5] 10 is an explanatory diagram illustrating an outline of another single-wafer type film forming apparatus provided in the substrate processing apparatus according to an embodiment of the present invention. FIG. [Figure 6] 1 is an explanatory diagram illustrating an outline of a batch-type film forming apparatus provided in a substrate processing apparatus according to an embodiment of the present invention. [Figure 7] 4 is a graph showing the relationship between the dissolved oxygen concentration and the bubbling time of the treatment liquid according to Example 1 of the present invention. [Figure 8] 1 is an electron microscope photograph showing the surface state of a substrate sample according to Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] (Substrate processing method) First, a substrate processing method according to this embodiment will be described below with reference to Figures 1 and 2. Figure 1 is a flowchart showing an example of the overall flow of a substrate processing method according to an embodiment of the present invention. Figures 2(a) to 2(d) are schematic diagrams showing an example of changes in substrate state in a film formation method according to an embodiment of the present invention, where Figure 2(a) shows a state in which a material for forming a self-assembled monolayer is supplied to the substrate surface, Figure 2(b) shows a state in which a self-assembled monolayer is formed in a metal film-forming region of the substrate surface, Figure 2(c) shows a state in which a film is formed in a metal film-non-forming region of the substrate surface, and Figure 2(d) shows a state in which the self-assembled monolayer is removed from the metal film-forming region of the substrate surface.

[0032] The substrate processing method of this embodiment provides a technique for selectively forming a film depending on the material of the substrate surface when forming a film on the surface of a substrate W. In this specification, the term "substrate" refers to various substrates such as semiconductor substrates, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks.

[0033] As shown in FIG. 1, the substrate processing method of this embodiment includes at least a substrate W preparation step S101, a processing solution dissolved oxygen concentration reduction step S102, a self-assembled monolayer (hereinafter referred to as "SAM") formation step S103, a film formation step S104, and a SAM removal step S105.

[0034] 1 and 2(a), the substrate W prepared in the substrate W preparation step S101 includes a metal film-formed region where the metal film 1 is exposed and a metal film-non-formed region where the insulating film 2 is exposed. More specifically, the substrate W may include, for example, a substrate having an insulating film 2 in which a trench having a given wiring width is formed, and a metal film 1 embedded in the trench. The substrate W preparation step may include, for example, loading the substrate W into a chamber (details of which will be described later) that is a container for accommodating the substrate W, using a substrate loading / unloading mechanism.

[0035] 2(a), there is one metal film-formed region and one metal film-non-formed region, but there may be multiple of each. For example, they may be arranged so that a strip-shaped metal film-non-formed region is interposed between adjacent strip-shaped metal film-formed regions, or so that a strip-shaped metal film-formed region is interposed between adjacent strip-shaped metal film-non-formed regions.

[0036] Furthermore, the substrate W of this embodiment is not limited to a case where only a metal film-formed region and a metal film-non-formed region are provided on its surface. For example, a region where another film made of a material different from the metal film 1 and the insulating film 2 is formed and exposed on the surface may be provided. In this case, the position where this region is provided is not particularly limited and can be set arbitrarily.

[0037] The metal film 1 is not particularly limited, and examples thereof include those made of copper (Cu), tungsten (W), ruthenium (Ru), germanium (Ge), silicon (Si), titanium nitride (TiN), cobalt (Co), molybdenum (Mo), etc.

[0038] The insulating film 2 is not particularly limited, and examples thereof include those made of silicon oxide (SiO2), hafnium oxide (HfO2), zirconia (ZrO2), silicon nitride (SiN), and the like.

[0039] The process S102 for reducing the dissolved oxygen concentration in the treatment solution is a process for reducing the dissolved oxygen concentration in the treatment solution containing the SAM-forming material, thereby reducing the etching of the metal film caused by oxidation of the metal film and the metal dissolving in the treatment solution.

[0040] The method for reducing the dissolved oxygen concentration of the treatment liquid is not particularly limited, and examples thereof include a method of bubbling the treatment liquid by supplying an inert gas into the treatment liquid, a method using a vacuum degassing device or an oxygen-permeable membrane, etc. Examples of inert gases include nitrogen (N2) gas, helium (He) gas, neon (Ne) gas, and argon (Ar) gas.

[0041] When reducing the dissolved oxygen concentration in the treatment solution by bubbling with an inert gas, this step is preferably performed under an inert gas atmosphere. This allows for further reduction in the dissolved oxygen concentration in the treatment solution. Furthermore, when performing the step under an inert gas atmosphere, the oxygen concentration in the inert gas atmosphere is preferably less than 0.1%, more preferably 100 ppm or less, and particularly preferably 10 ppm or less. Reducing the dissolved oxygen concentration in 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 in the treatment solution, thereby further reducing the dissolved oxygen concentration in the treatment solution. Examples of inert gases that can be used include nitrogen (N), helium (He), neon (Ne), and argon (Ar).

[0042] The dissolved oxygen concentration of the processing liquid after the dissolved oxygen concentration reducing step (or immediately before contacting the processing liquid with the substrate W) is preferably less than 100 ppb, more preferably 50 ppb or less, and particularly preferably 10 ppb or less.

[0043] The treatment liquid 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 or dispersed in the solvent.

[0044] The SAM-forming material is not particularly limited, and examples thereof include phosphonic acid compounds having a phosphonic acid group such as monophosphonic acid, diphosphonic acid, etc. These phosphonic acid compounds can be used alone or in combination of two or more.

[0045] 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 containing a fluorine atom; or a vinyl group). In this specification, when a range of carbon atoms is expressed, the range means that the range includes all integer carbon numbers included in the range. Therefore, for example, an alkyl group having "1 to 3 carbon atoms" means all alkyl groups having 1, 2, and 3 carbon atoms.

[0046] The alkyl group having 1 to 18 carbon atoms may be either linear or branched. The number of carbon atoms in the alkyl group is preferably in the range of 10 to 18, more preferably in the range of 14 to 18. The alkyl group having 1 to 18 carbon atoms and containing a fluorine atom may be either linear or branched. The number of carbon atoms in the alkyl group having a fluorine atom is preferably in the range of 10 to 18, more preferably in the range of 14 to 18.

[0047] Furthermore, specific examples of the monophosphonic acid represented by RP(=O)(OH)2 include compounds represented by any of the following chemical formulas (1) to (16).

[0048] [ka]

[0049] In addition to the above-mentioned examples, the monophosphonic acid may also be a compound represented by any one of the following chemical formulas (17) to (19).

[0050] [ka]

[0051] Diphosphonic acids include compounds represented by either of the following chemical formulas (20) and (21).

[0052] [ka]

[0053] Of the phosphonic acid compounds given as examples, octadecylphosphonic acid and the like are preferred from the viewpoint of forming a dense SAM.

[0054] The solvent in the treatment liquid is not particularly limited, and examples thereof include alcohol solvents, ether solvents, glycol ether solvents, glycol ester solvents, etc. The alcohol solvent is not particularly limited, and examples thereof include ethanol, etc. The ether solvent is not particularly limited, and examples thereof include tetrahydrofuran (THF), etc. The glycol ether solvent is not particularly limited, and examples thereof include propylene glycol monomethyl ether (PGME), etc. The glycol ester solvent is not particularly limited, and examples thereof include propylene glycol monomethyl ether acetate (PGMEA), etc. These solvents can be used alone or in combination of two or more. Furthermore, these solvents can be used in any combination with the phosphonic acid compound exemplified above. Of the exemplified solvents, alcohol solvents are preferred, and ethanol is particularly preferred, from the viewpoint of being able to dissolve the phosphonic acid compound.

[0055] The content of the SAM-forming material 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 0.02 mass % to 0.06 mass %, relative to the total mass of the treatment liquid.

[0056] The treatment liquid may contain known additives as long as they do not impair the effects of the present invention. The additives are not particularly limited, and examples thereof include stabilizers and surfactants.

[0057] 1, 2(a), and 2(b), the SAM formation step S103 is a step of forming a SAM 4 by bringing the treatment solution after the dissolved oxygen concentration reduction into contact with the surface of the substrate W and causing the SAM-forming material 3 contained in the treatment solution to adsorb onto the surface of the metal film 1. Here, the SAM 4 is selectively formed only on the metal film 1 in the metal film formation region of the substrate W, and not on the metal film non-formation region. For example, when the metal film 1 is a Cu (copper) film, the SAM 4 is formed only on the metal film 1 because the phosphonic acid group of the SAM-forming material 3, a phosphonic acid compound, reacts with the —OH group on the surface of the Cu film as represented by the following chemical reaction formula:

[0058] [ka]

[0059] Here, when the phosphonic acid compound is adsorbed onto the surface of the Cu film, HO is generated, but in the present invention, the dissolved oxygen concentration in the processing solution that is brought into contact with the substrate W is reduced in advance, thereby minimizing the dissolution of Cu into HO. Therefore, this embodiment can suppress etching of the Cu film compared to when a SAM is formed without reducing the dissolved oxygen concentration in the processing solution.

[0060] The method for contacting the processing liquid with the substrate W is not particularly limited, and examples include a method in which the processing liquid is applied to the surface of the substrate W, a method in which the processing liquid is sprayed onto the surface of the substrate W, and a method in which the substrate W is immersed in the processing liquid.

[0061] One method for applying the processing liquid to the surface of the substrate W is, for example, to supply the processing liquid to the central portion of the surface of the substrate W while the substrate W is being rotated at a constant speed around its central portion as an axis. In this way, the processing liquid supplied to the surface of the substrate W flows from near the center of the surface of the substrate W toward the peripheral edge of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and is spread over 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.

[0062] The SAM formation step S103 is preferably performed in an atmosphere in which the dissolved oxygen concentration of the treatment solution after the dissolved oxygen concentration has been reduced is maintained or reduced. This prevents oxygen contained in the atmosphere from dissolving in the treatment solution during the formation of the SAM 4. As a result, the reduced dissolved oxygen concentration of the treatment solution can be maintained well. When this step is performed in an inert gas atmosphere, the oxygen concentration in the inert gas atmosphere is preferably less than 0.1%, more preferably 100 ppm or less, and particularly preferably 10 ppm or less.

[0063] The SAM formation step S103 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 spinning off the processing liquid by centrifugal force by rotating the substrate W at a constant speed.

[0064] Furthermore, when performing a step of spinning 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 sufficiently spin off the processing liquid, but is usually set in the range of 800 rpm to 2500 rpm, preferably 1000 rpm to 2000 rpm, and more preferably 1200 rpm to 1500 rpm.

[0065] 1 and 2(c), the film formation step S104 is a step of forming a target film 5 on the insulating film 2 in the metal film non-forming region. At this time, the SAM 4 formed in the metal film forming region functions as a masking film to protect the metal film 1. This allows the target film 5 to be selectively formed in the metal film non-forming region.

[0066] The target film 5 is not particularly limited, and examples thereof include films made of aluminum oxide (Al2O3), cobalt oxide (CoO), zirconium oxide (ZrO2), etc. The method for forming these films 5 is also not particularly limited, and examples thereof include CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), vacuum deposition, sputtering, plating, thermal CVD, and thermal ALD.

[0067] 1 and 2(d), the removal step S105 is a step of removing the SAM4 formed in the metal film formation region after the step of forming the film 5. The method for removing the SAM4 is not particularly limited, and for example, a method of directly removing the SAM4 by dissolving or etching, or a method of thinly peeling off the surface portion of the metal film 1 together with the SAM4 can be used.

[0068] For example, when removing SAM4 made of a phosphonic acid compound, SAM4 can be oxidized by irradiating it with ultraviolet light, and then removed by contacting SAM4 with acetic acid. As a result, as shown in Figure 2(d), a film 5 is selectively formed only in the region where the metal film is not formed, and a substrate W with exposed metal film 1 can be obtained. The conditions for ultraviolet irradiation are not particularly limited and can be set appropriately as needed.

[0069] Furthermore, when removing SAM4 by etching, the SAM4 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 thereof include oxygen (O2) gas and ozone (O3) gas. These oxygen-containing gases may be heated to a high temperature to promote a chemical reaction. These oxygen-containing gases may also be in the form of plasma to promote a chemical reaction.

[0070] As described above, according to the substrate processing method of this embodiment, by forming SAM4 using a processing solution with a reduced dissolved oxygen concentration, etching of metal film 1 can be suppressed during the selective film formation process in the metal film formation region of SAM4.

[0071] (Substrate processing equipment) Next, the substrate processing apparatus according to this embodiment will be described with reference to Fig. 3. Fig. 3 is an explanatory view showing the main parts of the substrate processing apparatus according to this embodiment.

[0072] As shown in FIG. 3, the substrate processing apparatus 10 of this embodiment includes at least a processing liquid supply apparatus 100 for supplying a processing liquid, a film forming apparatus 200 for forming a SAM4, and a control unit 300 for controlling each part of the substrate processing apparatus 10.

[0073] [Processing liquid supply device] As shown in FIG. 3, the processing liquid supply device 100 according to this embodiment has the function of supplying a processing liquid having a reduced dissolved oxygen concentration from the beginning to a film forming device 200, and includes a processing liquid tank 11, a pressurizing section 12, and a pipe 13.

[0074] The processing liquid tank 11 may include an agitation unit that agitates the processing liquid in the processing liquid tank 11 and a temperature adjustment unit that adjusts the temperature of the processing liquid in the processing liquid tank 11 (neither is shown). The agitation unit may include a rotation unit that agitates the processing liquid in the processing liquid tank 11 and an agitation control unit that controls the rotation of the rotation unit. The agitation control unit is electrically connected to the control unit 300, and the rotation unit is equipped with, for example, a propeller-shaped agitation blade at the lower end of the rotation shaft. The control unit 300 issues an operation command to the agitation control unit to rotate the rotation unit, thereby agitating the processing liquid with the agitation blade. As a result, the concentration and temperature of the processing liquid in the processing liquid tank 11 can be made uniform.

[0075] The pressurizing unit 12 includes a nitrogen gas supply source 16, which is a gas supply source for pressurizing the processing liquid tank 11, a pump (not shown) for pressurizing the nitrogen gas, a nitrogen gas supply pipe 14, and a valve 15 provided midway along the nitrogen gas supply pipe 14. The nitrogen gas supply source 16 is connected to the processing liquid tank 11 via the nitrogen gas supply pipe 14. An air pressure sensor (not shown) electrically connected to the control unit 300 may be provided within the processing liquid tank 11. In this case, the control unit 300 can maintain the air pressure within 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 air pressure sensor. Furthermore, by electrically connecting the valve 15 to the control unit 300, the opening and closing of the valve 15 can be controlled by an operation command from the control unit 300. When the valve 15 is opened by an operation command from the control unit 300, the processing liquid is pressure-fed through the piping 13.

[0076] The pipe 13 branches into a first pipe 13a and a second pipe 13b. The first pipe 13a is connected to a first reservoir 21a, and the second pipe 13b is connected to a second reservoir 21b (the first reservoir 21a and the second reservoir 21b will be described in detail later). Furthermore, a first valve 16a is provided in the first pipe 13a, and a second valve 16b is provided in the second pipe 13b. The first valve 16a and the second valve 16b are each electrically connected to a control unit 300, and the opening and closing of the first valve 16a and the second valve 16b can be controlled by an operation command from the control unit 300. When the first valve 16a and the second valve 16b are opened by an operation command from the control unit 300, the treatment liquid can be supplied to the first reservoir 21a and the second reservoir 21b, respectively.

[0077] The processing liquid supplying apparatus 100 also includes a first storage section 21a and a second storage section 21b as storage sections for storing the processing liquid, and a first inert gas supplying section for supplying an inert gas to the first storage section 21a and the second storage section 21b, respectively.

[0078] In the first storage section 21a and the second storage section 21b, the processing liquid supplied from the processing liquid tank 11 is subjected to a process of reducing the dissolved oxygen concentration by using an inert gas supplied from a first inert gas supply section. The first storage section 21a and the second storage section 21b may each be provided with an agitation section that agitates the stored processing liquid and a temperature adjustment section that adjusts the temperature of the processing liquid (neither of which are shown). The agitation section may be the same as that which can be installed in the processing liquid tank 11.

[0079] The first inert gas supply unit includes an inert gas supply source 29, a pump (not shown) that pressurizes the inert gas, an inert gas supply pipe 22, and a valve 23 provided midway along the inert gas supply pipe 22. The inert gas supply pipe 22 branches into a first inert gas supply pipe 22a and a second inert gas supply pipe 22b downstream of the valve 23. The valve 23 is electrically connected to the control unit 300, so that the opening and closing of the valve 23 can be controlled by an operation command from the control unit 300. When the valve 23 is opened by an operation command from the control unit 300, the inert gas can be supplied to the first storage unit 21a and the second storage unit 21b.

[0080] A first upstream valve 23a and a first downstream valve 24a are sequentially provided along the first inert gas supply pipe 22a from upstream to downstream. Similarly, a second upstream valve 23b and a second downstream valve 24b are sequentially provided along the second inert gas supply pipe 22b from upstream to downstream. Furthermore, bubbling nozzles for discharging inert gas are provided at the ends of the first inert gas supply pipe 22a and the second inert gas supply pipe 22b, respectively. The bubbling nozzles are preferably located near the bottoms of the first and second storage sections 21a and 21b, below the liquid level of the stored processing liquid. The bubbling nozzles preferably have a plurality of outlets for discharging the inert gas. Furthermore, the bubbling nozzles preferably extend substantially horizontally relative to the bottoms of the first and second storage sections 21a and 21b.

[0081] The supply amount and supply time of the inert gas to first reservoir 21a and second reservoir 21b can be controlled by adjusting the aperture of first upstream valve 23a and / or first downstream valve 24a in first inert gas supply pipe 22a, and by adjusting the aperture of second upstream valve 23b and / or second downstream valve 24b in second inert gas supply pipe 22b. The apertures of first upstream valve 23a, first downstream valve 24a, second upstream valve 23b, and second downstream valve 24b can be adjusted by an operation command from control unit 300.

[0082] The degree of reduction in the dissolved oxygen concentration in the treatment liquid in first reservoir 21 a and second reservoir 21 b can be adjusted by controlling the supply amount and supply time of the inert gas. Also, by differentiating the supply amount and supply time of the inert gas supplied to first reservoir 21 a and second reservoir 21 b from first inert gas supply pipe 22 a and second inert gas supply pipe 22 b, respectively, the dissolved oxygen concentration of the treatment liquid stored in first reservoir 21 a and the dissolved oxygen concentration of the treatment liquid stored in second reservoir 21 b can be made different from each other.

[0083] A first branch pipe 22c is connected to the first inert gas supply pipe 22a so as to branch between the first upstream valve 23a and the first downstream valve 24a. A second branch pipe 22d is connected to the second inert gas supply pipe 22b so as to branch between the second upstream valve 23b and the second downstream valve 24b. A first exhaust pipe 25a and a second exhaust pipe 25b for reducing the internal pressure are connected to the first storage section 21a and the second storage section 21b, respectively. A first exhaust valve 26a and a second exhaust valve 26b are provided midway along the first exhaust pipe 25a and the second exhaust pipe 25b, respectively. The first exhaust pipe 25a and the second exhaust pipe 25b may each be connected to an exhaust pump (not shown). These configurations enable the reduction of the dissolved oxygen concentration in the first storage section 21a and the second storage section 21b to be performed under an inert gas atmosphere. For example, in the case of the first storage section 21a, the control section 300 issues an operational command to open the valve 23, the first upstream valve 23a, and the first exhaust valve 26a, and close the first downstream valve 24a. As a result, when the inert gas is supplied into the first storage section 21a, the air inside the first storage section 21a is discharged through the first exhaust pipe 25a, and the air is replaced with the inert gas. As a result, the inside of the first storage section 21a can be filled with an inert gas atmosphere, thereby reducing the oxygen concentration inside the first storage section 21a. When replacing the air inside the first storage section 21a and the second storage section 21b with the inert gas, an exhaust pump may be used to discharge the air from the first exhaust pipe 25a and the second exhaust pipe 25b. That is, the control unit 300 issues an operational command to open the first exhaust valve 26a and the second exhaust valve 26b and operate the exhaust pump, thereby discharging the air inside the first storage unit 21a and the second storage unit 21b, thereby quickly replacing the air with an inert gas.

[0084] Furthermore, a first discharge pipe 27a and a second discharge pipe 27b are connected to the first storage section 21a and the second storage section 21b, respectively, for supplying the treatment liquid after the dissolved oxygen concentration has been reduced to the film forming apparatus 200. A first discharge valve 28a and a second discharge valve 28b are provided midway through the first discharge pipe 27a and the second discharge pipe 27b, respectively. Furthermore, the first discharge pipe 27a and the second discharge pipe 27b are connected to a third discharge pipe 27c so as to merge downstream of the first discharge valve 28a and the second discharge valve 28b. The third discharge pipe 27c is provided midway through the third discharge valve 28c. Furthermore, a barometric pressure sensor electrically connected to the control section 300 may be provided inside the first storage section 21a and the second storage section 21b. In this case, the control unit 300 can maintain the air pressure in the first reservoir 21a and the second reservoir 21b at a predetermined air pressure higher than atmospheric pressure by controlling the operation of the pump based on the value detected by the air pressure sensor. Furthermore, by electrically connecting the first discharge valve 28a, the second discharge valve 28b, and the third discharge valve 28c to the control unit 300, the opening and closing of these valves can be controlled by operation commands from the control unit 300. When the first discharge valve 28a, the second discharge valve 28b, and the third discharge valve 28c are opened by the operation command from the control unit 300, the treatment liquid after the reduced dissolved oxygen concentration is pumped to the film forming apparatus 200 via the first discharge pipe 27a, the second discharge pipe 27b, and the third discharge pipe 27c.

[0085] In the present embodiment, the processing liquid supplying device 100 is described as including a pair of the first storage section 21a and the second storage section 21b. However, the present invention is not limited to this embodiment, and the number of storage sections may be, for example, one.

[0086] [Film forming equipment] Next, the film forming apparatus 200 will be described with reference to Fig. 4. Fig. 4 is an explanatory diagram showing an outline of the film forming apparatus 200 provided in the substrate processing apparatus 10.

[0087] The film forming apparatus 200 according to this embodiment is a single-wafer type film forming apparatus capable of forming the SAM 4 in the metal film formation region where the metal film 1 has been formed.

[0088] 4, the film forming apparatus 200 includes at least a substrate holding unit 30 that holds the substrate W, a supply unit 40 that supplies a processing liquid to the surface Wf of the substrate W, a chamber 50 that is a container that accommodates the substrate W, and a splash prevention cup 60 that collects the processing liquid. The film forming apparatus 200 may also include a loading / unloading means (not shown) that loads or unloads the substrate W.

[0089] The substrate holding unit 30 is a means for holding the substrate W, and as shown in Fig. 4, holds and rotates the substrate W in a substantially horizontal position with the substrate surface Wf facing upward. The substrate holding unit 30 has a spin chuck 31 in which a spin base 33 and a rotation support shaft 34 are integrally connected. The spin base 33 has a substantially circular shape in a plan view, and a hollow rotation support shaft 34 extending substantially vertically is fixed to its center. The rotation support shaft 34 is connected to a rotation shaft of a chuck rotation mechanism 36 including a motor. The chuck rotation mechanism 36 is housed in a cylindrical casing 37, and the rotation support shaft 34 is supported by the casing 37 so as to be rotatable about a vertical rotation axis.

[0090] The chuck rotation mechanism 36 can rotate the rotation support shaft 34 around the rotation axis J by being driven by a chuck drive unit (not shown) of the control unit 300. This causes the spin base 33 attached to the upper end of the rotation support shaft 34 to rotate around the rotation axis J. The control unit 300 can adjust the rotation speed of the spin base 33 by controlling the chuck rotation mechanism 36 via the chuck drive unit.

[0091] A plurality of chuck pins 35 for gripping the peripheral edge of the substrate W are provided upright near the peripheral edge of the spin base 33. There is no particular limitation on the number of chuck pins 35 to be provided, but it is preferable to provide at least three or more in order to securely hold the circular substrate W. In this embodiment, three chuck pins 35 are arranged at equal intervals along the peripheral edge 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 holds the substrate W by pressing against the outer peripheral edge surface of the substrate W supported by the substrate support pin.

[0092] The supply unit 40 is disposed 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 includes an annular opposing member 41 having an opening in the center, a second inert gas supply unit, a substantially cylindrical rotating support shaft 42 that supports the opposing member 41, an inserted shaft 43 that is inserted into the interior of the rotating support shaft 42 and the opening of the opposing member 41, and an arm 45.

[0093] The facing member 41 is attached approximately horizontally to the lower end of the rotating support shaft 42, and is disposed opposite the surface Wf of the substrate W held by the substrate holder 30. A lower surface (bottom surface) 44 of the facing member 41 serves as a substrate-facing surface that faces the surface Wf of the substrate W in approximately parallel relation. The lower surface 44 of the facing member 41 is formed to have a size equal to or greater than the diameter of the substrate W. A bearing (not shown) is provided between the inner peripheral surface of the rotating support shaft 42 and the outer peripheral surface of the inserted shaft 43, allowing the rotating support shaft 42 to rotate freely relative to the inserted shaft 43. The rotating support shaft 42 is held rotatably around a rotation axis J that passes through the center of the substrate W by an arm 45 extending horizontally.

[0094] The second inert gas supply unit includes an inert gas supply source 48, a pump (not shown) that pressurizes the inert gas, an inert gas supply pipe 49, and a valve 51 provided midway along the inert gas supply pipe 49. The inert gas supply path 47 is connected to the inert gas supply source 48 via the inert gas supply pipe 49. The valve 51 is electrically connected to the control unit 300, so that the opening and closing of the valve 51 can be controlled by an operation command from the control unit 300. When the valve 51 is opened by an operation command from the control unit 300, the inert gas can be supplied toward the front surface Wf of the substrate W.

[0095] The rotating support shaft 42 has therein a processing liquid supply path 46 through which the processing liquid flows and an inert gas supply path 47 through which the inert gas flows. The processing liquid supply path 46 is connected to the third discharge pipe 27c of the processing liquid supply device 100. The processing liquid supply path 46 also communicates with a discharge port (not shown) provided at the tip of the rotating support shaft 42. This allows the processing liquid to be discharged from the tip of the rotating support shaft 42. The inert gas supply path 47 is connected to an inert gas supply source 48 via an inert gas supply pipe 49. The inert gas supply path 47 also communicates with another discharge port (not shown) provided at the tip of the rotating support shaft 42. This allows the inert gas to be discharged from the tip of the rotating support shaft 42.

[0096] The supply unit 40 further includes a supply unit rotation mechanism 53 and a supply unit lifting mechanism 54. The supply unit rotation mechanism 53 and the supply unit lifting mechanism 54 are connected to the arms 45 of the rotation support shaft 42, respectively.

[0097] The supply unit rotation mechanism 53 is electrically connected to the control unit 300 and rotates the rotation support shaft 42 in response to an operation command from the control unit 300. This rotational movement causes the opposing member 41 to rotate integrally with the rotation support shaft 42. The supply unit rotation mechanism 53 can rotate the opposing member 41 in the same rotational direction and at approximately the same rotational speed as the substrate W in response to the rotation of the substrate W held by the substrate holding unit 30. When the inert gas is discharged from another discharge port, the opposing member 41 and the substrate W are rotated, and the resulting centrifugal force causes the inert gas to flow from the center of the substrate W toward the peripheral edge of the substrate W, thereby diffusing the inert gas over the entire surface Wf of the substrate W.

[0098] The supply unit lifting mechanism 54 is electrically connected to the control unit 300 and can lift and lower the supply unit 40 in response to an operation command from the control unit 300. This allows the facing member 41 of the supply unit 40 to approach or move away from the substrate W held by the substrate holder 30, thereby adjusting the distance between the lower surface 44 of the facing member 41 and the surface Wf of the substrate W. When an inert gas atmosphere is to be created on the surface Wf of the substrate W, the control unit 300 operates the supply unit lifting mechanism 54 to lower the supply unit 40. This brings the lower surface 44 of the facing member 41 closer to the surface Wf of the substrate W, forming a minute space 52. Furthermore, the control unit 300 opens the valve 51 in response to an operation command, causing the inert gas to be discharged from the outlet of the rotation support shaft 42 toward the surface Wf of the substrate W. This replaces the air in the space 52 between the lower surface 44 of the facing member 41 and the surface Wf of the substrate W with the inert gas. This creates an inert gas atmosphere in the space 52, thereby reducing the oxygen concentration in the space 52. As a result, fluctuations in the dissolved oxygen concentration in the processing liquid subsequently supplied to the surface Wf of the substrate W can be suppressed, further preventing etching of the metal film 1 by the processing liquid. Preferably, the formation of an inert gas atmosphere in the space 52 by supplying the inert gas is carried out before the start of the self-assembled monolayer-forming step S102. The inert gas may be supplied continuously or intermittently throughout the self-assembled monolayer-forming step S102.

[0099] When the substrate W is carried into or out of the film forming apparatus 200, the control unit 300 issues an operation command to operate the supply unit lifting mechanism 54, thereby lifting the supply unit 40. This allows the lower surface 44 of the facing member 41 and the front surface Wf of the substrate W to be spaced a certain distance apart, making it easier to carry the substrate W into or out of the film forming apparatus 200.

[0100] The splash prevention cup 60 is provided so as to surround the spin base 33. The splash prevention cup 60 is connected to a lifting drive mechanism (not shown) and is capable of moving up and down in the vertical direction. When supplying the processing liquid to the front surface Wf of the substrate W, the splash prevention cup 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. This makes it possible to collect the processing liquid splashed from the substrate W and the spin base 33.

[0101] Next, another film formation apparatus 201 will be described with reference to Fig. 5. Fig. 5 is an explanatory diagram showing an outline of another film formation apparatus provided in a substrate processing apparatus. In the other film formation apparatus shown in Fig. 5, components having the same configuration as the above-described film formation apparatus 200 are given the same reference numerals, and their description will be omitted.

[0102] 5, the other film formation apparatus 201 includes at least a substrate holding unit 30 that holds the substrate W, a supply unit 40' that supplies a processing liquid to the surface Wf of the substrate W, a chamber 50 that is a container that accommodates the substrate W, a third inert gas supply unit that supplies an inert gas into the chamber 50, a pressure reduction unit that exhausts gas from the chamber 50, and a splash prevention cup 60 that collects the processing liquid. The film formation apparatus 201 may also include a loading / unloading means (not shown) that loads or unloads the substrate W.

[0103] The supply unit 40' is disposed 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 66 and an arm 45. The nozzle 66 is attached to the tip of the arm 45, which extends horizontally, and is disposed above the spin base 33 when discharging the processing liquid.

[0104] The third inert gas supply unit includes an inert gas supply source 48, a pump (not shown) for pressurizing the inert gas, an inert gas supply pipe 49, a valve 51 provided midway along the inert gas supply pipe 49, an inline heater 61 provided downstream of the valve 51, and a pair of inert gas nozzles 62.

[0105] The pair of inert gas nozzles 62 are connected to an inert gas supply pipe 49 that branches off downstream of the inline heater 61. The inline heater 61, which is provided downstream of the valve 51, can heat the inert gas supplied from the inert gas supply source 48 to a predetermined temperature. The valve 51 is electrically connected to the control unit 300, so that the opening and closing of the valve 51 can be controlled by an operation command from the control unit 300. When the valve 51 is opened by an operation command from the control unit 300, the inert gas can be supplied into the chamber 50. The amount of inert gas supplied can be adjusted by controlling the opening degree of the valve 51. The inline heater 61 is also electrically connected to the control unit 300, so that heating can be controlled by an operation command from the control unit 300.

[0106] The pressure reducing unit includes at least an exhaust pump 63, an exhaust pipe 64, and an exhaust valve 65 provided midway along the exhaust pipe 64. The exhaust pump 63 is electrically connected to the control unit 300, so that exhaust by the exhaust pump 63 can be controlled by an operational command from the control unit 300. The exhaust valve 65 is also electrically connected to the control unit 300, so that opening and closing of the exhaust valve 65 can be controlled by an operational command from the control unit 300. When controlling the atmosphere in the chamber 50, the control unit 300 opens the valve 51 of the third inert gas supply unit. This causes the inert gas to be supplied into the chamber 50 from the inert gas supply source 48. The control unit 300 also operates the exhaust pump 63 and then opens the exhaust valve 65. In this way, in addition to supplying the inert gas into the chamber 50, the exhaust pump 63 can exhaust gas from the chamber 50, thereby creating an inert gas atmosphere in the chamber 50. As a result, the oxygen concentration in the chamber 50 can be reduced, and fluctuations in the dissolved oxygen concentration of the processing liquid supplied to the surface Wf of the substrate W can be suppressed, thereby further preventing etching of the metal film 1 by the processing liquid.

[0107] In the above description, an example has been described in which the film formation apparatus in the substrate processing apparatus of the present invention is a single-wafer type that processes substrates W one by one. However, the substrate processing apparatus of the present invention is not limited to this form, and can also be applied to another form of the substrate processing apparatus of the present invention, in which the film formation apparatus is a batch type that processes multiple substrates at once. Below, a case in which the substrate processing apparatus according to this embodiment is equipped with a batch-type film formation apparatus will be described with reference to FIG. 6. FIG. 6 is an explanatory diagram showing an outline of a batch-type film formation apparatus 202 in the substrate processing apparatus. In the film formation apparatus 202 shown in FIG. 6, components having the same configuration as the above-mentioned film formation apparatuses 200 and 201 are assigned the same reference numerals, and their description will be omitted.

[0108] As shown in Figure 6, the film forming apparatus 202 at least includes a processing tank 70 that stores a processing liquid in the tank and can accommodate multiple substrates W immersed in the processing liquid simultaneously, a liquid delivery unit 90 that supplies the processing liquid into the tank of the processing tank 70, a lifter 71 that can hold and move multiple substrates W, a chamber 80 that surrounds the processing tank 70, a third inert gas supply unit that supplies an inert gas into the chamber 80, and a pressure reduction unit that evacuates the gas inside the chamber 80.

[0109] The processing tank 70 is capable of storing the processing liquid after the dissolved oxygen concentration has been reduced, and is disposed downstream of the processing liquid supply device 100 (more specifically, the first storage section 21a and the second storage section 21b). The processing tank 70 is also capable of accommodating multiple substrates W in an upright position (upright posture). The upright position (upright posture) refers to a state in which the substrates W are held so that the surface Wf of the substrates W is approximately perpendicular to a horizontal plane. By accommodating the substrates W in the processing tank 70 in which the processing liquid has been stored, the substrates W can be immersed in the processing liquid.

[0110] The lifter 71 can hold multiple substrates W in an upright position. The lifter 71 can move up and down by a lifting mechanism (not shown). The lifter 71 moves the multiple substrates W it holds between an out-chamber standby position P1 outside the chamber 80 and above the chamber 80, an out-tank position P2 inside the chamber 80 and above the processing tank 70, and an in-tank position P3 inside the chamber 80 and in the processing tank 70.

[0111] The chamber 80 is provided with an upper cover 81 that can be opened and closed at the top of the chamber 80. When the upper cover 81 is opened, the lifter 71 that holds the plurality of substrates W enters the chamber 80 and becomes able to move the plurality of substrates W that it holds in an upright state in the vertical direction between an outside-chamber standby position P1 and a position inside the chamber 80.

[0112] The liquid delivery unit 90 supplies the processing liquid, the dissolved oxygen concentration of which has been reduced, supplied from the processing liquid supply device 100 into the processing tank 70. The liquid delivery unit 90 includes a supply pipe 91 connected to the third discharge pipe 27c of the processing liquid supply device 100, a valve 92 provided midway along the supply pipe 91, and two ejection pipes 93 connected to the supply pipe 91 and capable of ejecting the processing liquid into the processing tank 70. The two ejection pipes 93 have their major axes aligned in the direction in which the substrates W held by the lifter 71 are aligned (into the plane of the drawing), and are provided at the bottom of the processing tank 70. The valve 92 is electrically connected to the control unit 300, and the opening and closing of the valve 92 can be controlled by an operation command from the control unit 300. When the valve 92 is opened by an operation command from the control unit 300, the processing liquid can be ejected from the ejection pipes 93 into the processing tank 70.

[0113] As described above, the third inert gas supply unit includes an inert gas supply source 48, a pump (not shown) for pressurizing the inert gas, an inert gas supply pipe 49, a valve 51 provided midway along the inert gas supply pipe 49, an inline heater 61 provided downstream of the valve 51, and a pair of inert gas nozzles 62.

[0114] As described above, the pressure reducing section includes at least the exhaust pump 63, the exhaust pipe 64, and the exhaust valve 65 provided midway along the exhaust pipe 64.

[0115] The third inert gas supply unit and the decompression unit can control the atmosphere in the chamber 80. The third inert gas supply unit and the decompression unit can form an inert gas atmosphere in the chamber 80. When forming an inert gas atmosphere in the chamber 80, the control unit 300 opens the valve 51 of the third inert gas supply unit. An inert gas is supplied into the chamber 80 from the inert gas supply source 48. The control unit 300 also operates the exhaust pump 63. Next, the control unit 300 opens the exhaust valve 65. Then, in addition to supplying the inert gas into the chamber 80, the exhaust pump 63 exhausts the gas in the chamber 80. As a result, an inert gas atmosphere is formed in the chamber 80.

[0116] Furthermore, when controlling the atmosphere in the chamber 80, the third inert gas supply unit can supply the inert gas heated by the inline heater 61 into the chamber 80. This further accelerates drying of the substrate W that has been pulled out of the processing liquid in the processing bath 70 and has the processing liquid adhering thereto.

[0117] Next, the operation of the batch-type film formation apparatus 202 will be described. The upper cover 81 on the top of the chamber 80 is opened. Next, the lifter 71 enters the chamber 80 and moves the plurality of unprocessed substrates W held in an upright position from an outside-chamber standby position P1 outside the chamber 80 to an outside-tank position P2 inside the chamber 80. Then, the upper cover 81 closes the chamber 80.

[0118] The control unit 300 opens the valve 51 of the third inert gas supply unit. Inert gas is supplied into the chamber 80 from the inert gas supply source 48. The control unit 300 activates the exhaust pump 63. Next, the control unit 300 opens the exhaust valve 65. As a result, in addition to supplying the inert gas into the chamber 80, the exhaust pump 63 exhausts the gas inside the chamber 80. Then, the inside of the chamber 80 becomes an atmosphere of the inert gas.

[0119] The control unit 300 opens the valve 92. The processing liquid, whose dissolved oxygen concentration has been reduced and which is supplied from the processing liquid supply device 100, is sprayed from the spray pipe 93 into the processing tank 70. As a result, the processing liquid sprayed into the processing tank 70 is stored in the processing tank 70.

[0120] The lifter 71 moves the multiple substrates W it holds from an outside position P2 above the processing tank 70 to an inside position P3 within the processing tank 70. As a result, the multiple substrates W held by the lifter 71 are accommodated in the processing tank 70, in which the processing liquid is stored. The multiple substrates W held by the lifter 71 are immersed in the processing liquid stored in the processing tank 70. As a result, the processing liquid after the dissolved oxygen concentration reduction comes into contact with the surfaces Wf of the multiple substrates W. As the processing liquid comes into contact with the surfaces Wf of the substrates W, a SAM4 is formed in the metal film formation region on the surfaces Wf of the substrates W where the metal film 1 was formed.

[0121] Next, the lifter 71 moves the plurality of substrates W it holds from the intra-tank position P3 to the extra-tank position P2. As a result, the plurality of substrates W immersed in the processing liquid are lifted up from within the processing tank 70. The plurality of substrates W held by the lifter 71 are exposed from the processing liquid stored in the processing tank 70 to the inert gas atmosphere formed in the chamber 80. The remaining processing liquid adhering to the surfaces Wf of the substrates W is vaporized by being exposed to the inert gas atmosphere. As a result, the surfaces Wf of the substrates W are dried. The plurality of substrates W held by the lifter 71 are dried, for example, at the extra-tank position P2.

[0122] The control unit 300 stops the operation of the exhaust pump 63. The control unit 300 closes the exhaust valve 65. Furthermore, the control unit 300 closes the valve 51 of the third inert gas supply unit. This stops the atmosphere control in the chamber 80.

[0123] The upper cover 81 on the upper part of the chamber 80 is opened. The lifter 71 moves from the outside-tank position P2 to the outside-chamber standby position P1. As a result, the plurality of substrates W are unloaded from the chamber 80.

[0124] As described above, in the batch-type film formation apparatus 202, the oxygen concentration in the chamber 80 can be reduced by creating an inert gas atmosphere in the chamber 80. Furthermore, by reducing the oxygen concentration in the chamber 80, fluctuations in the dissolved oxygen concentration of the processing liquid stored in the processing tank 70 can be suppressed, and the dissolved oxygen concentration can be maintained at a reduced level. As a result, etching of the metal film 1 by the processing liquid can be further prevented. Furthermore, fluctuations in the dissolved oxygen concentration of the processing liquid remaining on the front surface Wf of the substrate W after it is pulled out of the processing tank 70 can also be suppressed. This further prevents the metal film 1 from being etched by the processing liquid remaining on the front surface Wf of the substrate W.

[0125] Furthermore, in the batch-type film formation apparatus 202, the third inert gas supply unit and the pressure reduction unit control the atmosphere in the chamber 80, thereby facilitating drying of the substrates W having the processing liquid adhered thereto after being lifted out of the processing bath 70. Furthermore, the third inert gas supply unit and the pressure reduction unit form an inert gas atmosphere in the chamber 80, thereby evaporating the processing liquid adhered to the surface Wf of the substrates W, thereby facilitating drying of the substrates W. The multiple substrates W held by the lifter 71 are dried, for example, at an outside-bath position P2.

[0126] Furthermore, when controlling the atmosphere in the chamber 80, the third inert gas supply unit can supply the inert gas heated by the inline heater 61 into the chamber 80. This can further promote drying of the substrate W having the processing liquid attached thereto.

[0127] [Control Unit] The control unit 300 is electrically connected to each part of the substrate processing apparatus 10 and controls the operation of each part. The control unit 300 is composed of a computer having an arithmetic unit and a memory unit. The arithmetic unit uses a CPU that performs various arithmetic operations. The memory unit also includes a ROM, which is a read-only memory that stores the substrate processing program, a RAM, which is a read / write memory that stores various information, and a magnetic disk that stores control software, data, etc. The magnetic disk pre-stores substrate processing conditions, including the process for reducing the dissolved oxygen concentration of the processing liquid, the inert gas supply conditions, and the SAM4 film formation conditions. The CPU reads the substrate processing conditions into the RAM and controls each part of the substrate processing apparatus 10 according to the contents of the read conditions.

[0128] (Other matters) The processing liquid supply apparatus of this embodiment may be used in various apparatuses other than the substrate processing apparatus, or may be used independently. The above description has been given of the most preferred embodiment of the present invention. However, the present invention is not limited to this embodiment. The configurations in the above-described embodiment and each modification can be changed, modified, substituted, added, deleted, and combined within the scope of not mutually contradicting each other. [Example]

[0129] Preferred examples of the present invention are described in detail below. However, the materials, amounts, conditions, etc. described in these examples are not intended to limit the scope of the present invention unless otherwise specified.

[0130] Example 1 [Preparation of treatment solution and treatment to reduce dissolved oxygen concentration] Octadecylphosphonic acid (CH3(CH2)) as a SAM-forming material 17 The treatment solution according to this example was prepared by dissolving P(=O)(OH)2) in an ethanol solvent. The concentration of octadecylphosphonic acid was 0.04% by mass relative to the total mass of the treatment solution.

[0131] Next, the dissolved oxygen concentration of the treatment solution immediately after preparation was measured using a dissolved oxygen meter (product name: Field-type multi-digital water quality meter LAQUA WQ-310, manufactured by Horiba, Ltd.) The result showed that the initial dissolved oxygen concentration of the treatment solution was 6000 ppb.

[0132] Next, the treatment liquid was subjected to a treatment to reduce the dissolved oxygen concentration in a glove box. To reduce the dissolved oxygen concentration, the glove box was first filled with a nitrogen gas atmosphere to reduce the oxygen concentration to less than 0.1%, and then nitrogen gas was supplied to the treatment liquid placed in a container and bubbled. The nitrogen gas bubbling was performed for a bubbling time (nitrogen gas supply time) of 5 minutes. Figure 7 shows a graph showing the relationship between the dissolved oxygen concentration of the treatment liquid and the bubbling time. The dissolved oxygen concentration of the treatment liquid after the dissolved oxygen concentration reduction treatment was measured using the dissolved oxygen meter described above. The result was that the dissolved oxygen concentration of the treatment liquid after the dissolved oxygen concentration reduction was 100 ppb.

[0133] [SAM formation and removal] The SAM was formed on the surface of a substrate using the treatment solution after the treatment for reducing the dissolved oxygen concentration. Specifically, a substrate was prepared with an interlayer insulating film made of SiO2 film (thickness 200 nm) in which a trench with a wiring width of 100 nm was formed, and a Cu film (thickness 200 nm) as a metal film embedded in the trench.

[0134] Next, the surface of this substrate was coated with the treatment solution after the treatment to reduce the dissolved oxygen concentration, and a SAM was formed by adsorbing octadecylphosphonic acid onto the Cu film. Subsequently, the SAM on the Cu film was irradiated with ultraviolet light, and then the SAM was removed by contacting with an acetic acid solution, thereby producing a sample according to this example.

[0135] (Comparative Example 1) In this comparative example, the treatment solution was not subjected to treatment to reduce the dissolved oxygen concentration. Otherwise, the SAM was formed on the Cu film and the SAM was removed in the same manner as in Example 1, to prepare a substrate sample according to this comparative example. The initial dissolved oxygen concentration of the treatment solution was 6000 ppb.

[0136] (surface roughness measurement) The centerline average roughness Ra and maximum height Rmax were measured for the substrate before SAM formation, and for each substrate sample according to Example 1 and Comparative Example 1. An AFM (atomic force microscope, trade name: Dimension ICON-PT, manufactured by Bruker Japan Co., Ltd.) was used for the measurements. Ra was measured at three points in the metal film-formed regions No. 1 to 3 on which the Cu film was formed, as shown in FIG. 8, and the average value was calculated. Rmax was measured at three points in the regions No. 1 to 3 perpendicular to the direction in which the metal film-formed region and the metal film-free region extended, as shown in FIG. 8, and the average value was calculated. The results are shown in Table 1. FIG. 8 is an electron microscope photograph showing the surface condition of the substrate sample according to Example 1 of the present invention.

[0137] [Table 1]

[0138] As can be seen from Table 1, in Comparative Example 1, the SAM was formed using a treatment solution with a dissolved oxygen concentration of 6000 ppb, which confirmed that the centerline average roughness (Ra) of the Cu film surface was larger than that of the substrate before SAM formation. Furthermore, the maximum height (Rmax) was also larger, confirming that the step between the Cu film and the SiO2 film was enlarged. On the other hand, in Example 1, the SAM was formed using a treatment solution with a dissolved oxygen concentration reduced to 100 ppb, which enabled the centerline average roughness (Ra) of the Cu film surface to be reduced compared to the substrate before SAM formation and the substrate of Comparative Example 1. Furthermore, the maximum height (Rmax) was also reduced compared to the substrate before SAM formation and the substrate of Comparative Example 1, confirming that the step between the Cu film and the SiO2 film was reduced. This confirms that using a treatment solution with a reduced dissolved oxygen concentration when forming a SAM on the Cu film surface can prevent the Cu film from being oxidized and etched. [Explanation of symbols]

[0139] 1 Metal film 2. Insulating film 3. SAM-forming materials (self-assembled monolayer-forming materials) 4 SAM (Self-assembled monolayer) 5 membrane 10. Substrate processing equipment 11 Processing liquid tank 12 Pressure section 13 Piping 13a First Pipe 13b Second piping 14 Nitrogen gas supply pipe 15 valves 16 Nitrogen gas supply source 16a First valve 16b Second valve 21a First storage section 21b Second storage section 22 Inert gas supply pipe 22a First inert gas supply pipe 22b Second inert gas supply pipe 22c First branch pipe 22d Second branch pipe 23 Valve 23a First upstream valve 23b Second upstream valve 24a First downstream valve 24b Second downstream valve 25a 1st discharge pipe 25b 2nd discharge pipe 26a First exhaust valve 26b Second exhaust valve 27a 1st discharge pipe 27b 2nd discharge pipe 27c 3rd discharge pipe 28a First discharge valve 28b Second discharge valve 28c Third exhaust valve 29, 48 Inert gas supply source 30 Board holding part 40 Supply section 41 opposing member 42 Rotating shaft 43 Interpolation axis 44 Bottom surface 46 Processing liquid supply path 47 Inert gas supply line 49 Inert gas supply pipe 50, 80 chambers 51 Valve 52 Space 53 Supply unit rotation mechanism 54 Supply section lifting mechanism 60 Shatterproof Cups 61 Inline heater 62 Inert gas nozzle 63 Exhaust pump 64 Exhaust pipe 65 Exhaust valve 66 nozzles 70 Treatment tank 90 Liquid delivery section 100 Processing liquid supply device 200, 201, 202 Film deposition equipment 300 control section S101 Preparation process S102 Dissolved oxygen concentration reduction process S103 Self-assembled monolayer (SAM) formation process S104 Film formation process S105 Removal process W substrate Wf substrate surface

Claims

1. 1. A substrate processing method for processing a substrate having, on a surface thereof, a metal film-formed region where a metal film is formed and a metal film-free region where the metal film is not formed, the method comprising: a dissolved oxygen concentration reduction step of reducing the dissolved oxygen concentration of a treatment solution containing a material for forming a self-assembled monolayer; a self-assembled monolayer forming step of forming the self-assembled monolayer on the metal film in the metal film formation region while suppressing oxidation of the metal film by bringing the treatment liquid after the dissolved oxygen concentration reducing step into contact with at least the surface of the substrate; A substrate processing method comprising:

2. 2. The substrate processing method according to claim 1, wherein the dissolved oxygen concentration reducing step reduces the dissolved oxygen concentration of the processing liquid by bubbling an inert gas into the processing liquid.

3. 3. The substrate processing method according to claim 2, wherein the dissolved oxygen concentration reducing step is performed in an inert gas atmosphere.

4. 4. The substrate processing method according to claim 1, wherein the self-assembled monolayer forming step is performed in an atmosphere in which the dissolved oxygen concentration of the processing solution after the dissolved oxygen concentration has been reduced is maintained or reduced.

5. 5. The substrate processing method according to claim 1, wherein the dissolved oxygen concentration of the processing liquid after the dissolved oxygen concentration reducing step is less than 100 ppb.

6. 6. The substrate processing method according to claim 1, wherein the processing liquid contains a phosphonic acid compound having a phosphonic acid group that is adsorbed to the surface of the metal film, and a solvent.

7. a film formation step of selectively forming a film on the metal film non-formation region using the self-assembled monolayer formed on the metal film formation region as a protective film after the self-assembled monolayer formation step; a removing step of removing the self-assembled monolayer formed in the metal film formation region to expose the metal film after the film forming step; The substrate processing method according to any one of claims 1 to 6, further comprising:

8. 1. A substrate processing apparatus for processing a substrate having, on its surface, a metal film-formed region where a metal film is formed and a metal film-free region where the metal film is not formed, a reservoir for storing a treatment liquid containing a material for forming a self-assembled monolayer; a first inert gas supply unit that supplies an inert gas into the treatment liquid stored in the storage unit to reduce the dissolved oxygen concentration of the treatment liquid; a supply unit that supplies the treatment liquid after the dissolved oxygen concentration has been reduced to the surface of the substrate, and forms the self-assembled monolayer on the metal film in the metal film formation region while suppressing oxidation of the metal film; A substrate processing apparatus comprising:

9. A substrate processing apparatus for collectively processing a plurality of substrates each having a metal film-formed region on which a metal film is formed and a metal film-free region on which the metal film is not formed, the apparatus comprising: a reservoir for storing a treatment liquid containing a material for forming a self-assembled monolayer; a first inert gas supply unit that supplies an inert gas into the treatment liquid stored in the storage unit to reduce the dissolved oxygen concentration of the treatment liquid; a liquid delivery unit that delivers the treatment liquid after the dissolved oxygen concentration has been reduced from the storage unit downstream; a treatment tank that stores the treatment liquid after the dissolved oxygen concentration has been reduced and that has been delivered by the liquid delivery unit, and immerses the plurality of substrates in the treatment liquid all at once to form the self-assembled monolayer on the metal film in the metal film formation region on the surface of each substrate while suppressing oxidation of the metal film; A substrate processing apparatus comprising:

10. 10. The substrate processing apparatus according to claim 8, wherein the first inert gas supply unit supplies the inert gas into the storage unit to create an inert gas atmosphere inside the storage unit, and supplies the inert gas into the processing liquid stored in the storage unit to reduce the dissolved oxygen concentration of the processing liquid.

11. The supply unit includes: an opposing member that faces the surface of the substrate in close proximity at an arbitrary separation distance; a second inert gas supply unit that supplies an inert gas toward a space between the surface of the substrate and the facing member; and the second inert gas supply unit supplies the inert gas toward the space, thereby creating an atmosphere in the space in which the dissolved oxygen concentration of the treatment liquid after the dissolved oxygen concentration reduction is maintained or reduced; The substrate processing apparatus according to claim 8 , wherein the supply unit supplies the processing liquid with a reduced dissolved oxygen concentration to the surface of the substrate in an atmosphere in which the dissolved oxygen concentration of the processing liquid is maintained or reduced.

12. a chamber for supplying the processing liquid to the surface of the substrate by the supply unit within a sealed space; a third inert gas supply unit that supplies an inert gas into the chamber; a pressure reducing section that exhausts gas from the chamber; Furthermore, the third inert gas supply unit supplies the inert gas into the chamber, and the pressure reduction unit exhausts the gas in the chamber, thereby creating an atmosphere in the chamber in which the dissolved oxygen concentration of the treatment liquid after the dissolved oxygen concentration reduction is maintained or reduced; The substrate processing apparatus according to claim 8 , wherein the supply unit supplies the processing liquid with a reduced dissolved oxygen concentration to the surface of the substrate in an atmosphere in which the dissolved oxygen concentration of the processing liquid is maintained or reduced.

13. 13. The substrate processing apparatus according to claim 8, further comprising a control unit that controls the first inert gas supply unit so that the dissolved oxygen concentration of the processing liquid after the dissolved oxygen concentration reduction is less than 100 ppb.

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