Self-assembled monolayer removal solution, and substrate processing method and apparatus using the same.

Abstract

This invention relates to a self-assembled monolayer removal solution, and a substrate processing method and apparatus using the same. The invention provides a self-assembled monolayer removal solution for selectively removing self-assembled monolayers disposed on a substrate surface, wherein the Hansen solubility parameter of the self-assembled monolayer removal solution is located in the Hansen solubility parameter space with a central value (δd1, δp1, δh1) [MPa]. 1 / 2 ] and sphere radius R1 [MPa 1 / 2 The self-assembled monolayer forming material is located within the first Hansen sphere 1 of the specified material, and is situated in the Hansen solubility parameter space by the center values ​​(δd2, δp2, δh2) [MPa]. 1 / 2 ] and sphere radius R2 [MPa 1 / 2 The second Hansen sphere 2 of the self-assembled monolayer as specified in the regulations.

Description

Technical Field

[0001] The present invention relates to a self-assembled monomolecular membrane removal liquid capable of selectively removing self-assembled monomolecular membranes disposed on the surface of a substrate, and a substrate processing method and substrate processing apparatus using the same. Background Technology

[0002] In the manufacture of semiconductor devices, photolithography is widely used as a technique to selectively form films on designated surface areas of a substrate. For example, after forming the underlying wiring, an insulating film is formed, and a bimetallic damascene structure with trenches and vias is formed using photolithography and etching. Conductive films such as Cu are buried in the trenches and vias to form wiring.

[0003] However, as semiconductor devices become increasingly miniaturized, the positioning accuracy used in photolithography is sometimes insufficient. Therefore, the industry needs a method to form films with high precision and selectivity in designated areas on the substrate surface to replace photolithography.

[0004] For example, U.S. Patent No. 10,867,850 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 in substrate regions where SAM is not formed. Furthermore, according to this patent document, after selectively forming the film, acetic acid is used to remove the SAM.

[0005] However, the film-forming method proposed in this patent document has the problem of insufficient selective removal of SAM by acetic acid. Summary of the Invention

[0006] The present invention was made in view of the aforementioned problems, and its object is to provide a self-assembled monomolecular film removal liquid capable of selectively removing self-assembled monomolecular films disposed on the surface of a substrate, as well as a substrate processing method and substrate processing apparatus using the same.

[0007] To address the aforementioned problem, the self-assembled monomolecular membrane removal solution of the present invention is characterized in that it is used to selectively remove self-assembled monomolecular membranes disposed on the surface of a substrate, wherein the Hansen solubility parameter of the self-assembled monomolecular membrane removal solution is located in the Hansen solubility parameter space with a central value (δd1, δp1, δh1) [MPa]. 1 / 2 ] and sphere radius R1 [MPa 1 / 2 The self-assembled monolayer forming material is located within the first Hansen sphere of the specified material, and is situated in the Hansen solubility parameter space by the central values ​​(δd2, δp2, δh2) [MPa]. 1 / 2 ] and sphere radius R2 [MPa 1 / 2The second Hansen sphere of the self-assembled monolayer as specified in the diagram.

[0008] The first Hansen sphere in the aforementioned configuration is defined in the Hansen solubility parameter space by the Hansen solubility parameter of the self-assembled monolayer forming material. Furthermore, since the Hansen solubility parameter of the self-assembled monolayer removal solution is located within the first Hansen sphere, the self-assembled monolayer removal solution has high affinity for the structural molecules of the self-assembled monolayer and good solubility. Therefore, the self-assembled monolayer can be well dissolved and removed from the substrate surface. Additionally, the second Hansen sphere in the aforementioned configuration is defined in the Hansen solubility parameter space by the Hansen solubility parameter of the self-assembled monolayer. Furthermore, since the Hansen solubility parameter of the self-assembled monolayer removal solution is located within the second Hansen sphere, the self-assembled monolayer removal solution has high affinity for the self-assembled monolayer and good wettability. Therefore, when the self-assembled monolayer removal solution comes into contact with the self-assembled monolayer, it well wets and spreads to the surface of the self-assembled monolayer, thus further promoting the dissolution and removal of the self-assembled monolayer.

[0009] That is, when it is the self-assembled monomolecular membrane removal solution with the above-described structure, it has good solubility for self-assembled monomolecular membranes and good wettability. Therefore, for example, compared with conventional self-assembled monomolecular membrane removal solutions that only have good solubility, it can exert excellent removal performance on self-assembled monomolecular membranes.

[0010] In this configuration, the Hansen solubility parameter of the self-assembled monomolecular membrane removal solution is preferably a value located at the center of the circle formed by the intersection of the first Hansen sphere and the second Hansen sphere, or a value located at the tangent point of the first Hansen sphere and the second Hansen sphere. This provides a self-assembled monomolecular membrane removal solution with excellent balance between solubility and wettability for self-assembled monomolecular membranes, and superior removal performance for self-assembled monomolecular membranes.

[0011] Furthermore, in the aforementioned configuration, the self-assembled monolayer is formed by octadecylphosphonic acid, and the self-assembled monolayer comprises a monolayer of octadecylphosphonic acid. The first Hansen sphere can be defined in the Hansen solubility parameter space by the central values ​​(δd1, δp1, δh1) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa]. 1 / 2 ] Sphere radius R1 = 3.7 [MPa] 1 / 2 The second Hansen sphere is defined as having a central value (δd2, δp2, δh2) = (16.4±0.7, 6.1±1.2, 0.0±2.0) [MPa] in the Hansen solubility parameter space. 1 / 2 ], Sphere radius R2 = 10.2 [MPa] 1 / 2 ]Regulation.

[0012] When the above configuration is used, the Hansen solubility parameters of the self-assembled monolayer removal solution are set to the central values ​​(δd1, δp1, δh1) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa]. 1 / 2 ] Sphere radius R1 = 3.7 [MPa] 1 / 2 Within the first Hansen sphere as specified, and denoted by the center values ​​(δd2, δp2, δh2) = (16.4 ± 0.7, 6.1 ± 1.2, 0.0 ± 2.0) [MPa] 1 / 2 ], Sphere radius R2 = 10.2 [MPa] 1 / 2 Within the second Hansen sphere specified, not only is the affinity of the self-assembled monolayer removal solution for octadecylphosphonic acid improved, resulting in good solubility, but also its affinity for the octadecylphosphonic acid monolayer is improved, resulting in good wettability. Therefore, when the self-assembled monolayer removal solution with the aforementioned configuration is used, it exhibits superior removal performance, for example, compared to conventional self-assembled monolayer removal solutions that only have good solubility for octadecylphosphonic acid monolayers.

[0013] Furthermore, in the aforementioned configuration, the self-assembled monomolecular membrane removal solution is preferably at least one organic solvent selected from the group consisting of 1-butanol, 2-butanol, 1-pentanol, tetrahydrofuran, and benzyl alcohol.

[0014] To address the aforementioned problem, the substrate processing method of the present invention is characterized by: it being a method for processing a substrate on which a self-assembled monomolecular film is disposed, comprising: a preparation step of preparing a self-assembled monomolecular film removal liquid for selectively removing the self-assembled monomolecular film from the substrate; and a removal step of contacting the self-assembled monomolecular film removal liquid with the self-assembled monomolecular film to selectively remove the self-assembled monomolecular film from the substrate; and the preparation step being a step of preparing a self-assembled monomolecular film removal liquid having a Hansen solubility parameter located in the Hansen solubility parameter space with a center value (δd1, δp1, δh1) [MPa]. 1 / 2 ] and sphere radius R1 [MPa 1 / 2 The self-assembled monolayer forming material is located within the first Hansen sphere of the specified material, and is situated in the Hansen solubility parameter space by the central values ​​(δd2, δp2, δh2) [MPa]. 1 / 2 ] and sphere radius R2 [MPa 1 / 2 The second Hansen sphere of the self-assembled monolayer as specified in the diagram.

[0015] According to the aforementioned configuration, in the preparation step of the self-assembled monomolecular membrane removal solution, a self-assembled monomolecular membrane removal solution in which the Hansen solubility parameter is located within a first Hansen sphere and a second Hansen sphere is prepared, and the aforementioned operations are performed to prepare the self-assembled monomolecular membrane removal solution. Furthermore, the first Hansen sphere is defined by the Hansen solubility parameter of the self-assembled monomolecular membrane forming material, and the second Hansen sphere is defined by the Hansen solubility parameter of the self-assembled monomolecular membrane. Therefore, the self-assembled monomolecular membrane removal solution exhibits not only good solubility for the self-assembled monomolecular membrane but also good wettability. Therefore, when the processing method with the aforementioned configuration is used, when the self-assembled monomolecular membrane removal solution comes into contact with the self-assembled monomolecular membrane, it effectively wets and extends to the surface of the self-assembled monomolecular membrane. Therefore, compared to conventional processing methods, such as those using only self-assembled monomolecular membrane removal solutions with good solubility, the self-assembled monomolecular membrane can be removed more effectively.

[0016] In the aforementioned configuration, the preparation step is preferably a step in which the self-assembled monolayer removal solution is prepared such that its Hansen solubility parameter is a value located at the center of the circle formed by the intersection of the first Hansen sphere and the second Hansen sphere, or a value located at the point of tangency between the first Hansen sphere and the second Hansen sphere. This allows for the preparation of a self-assembled monolayer removal solution with an excellent balance between solubility and wettability for self-assembled monolayers. As a result, self-assembled monolayers can be removed more effectively.

[0017] Furthermore, in the aforementioned configuration, the self-assembled monolayer is formed by octadecylphosphonic acid, and the self-assembled monolayer comprises a monolayer of octadecylphosphonic acid. The first Hansen sphere can be defined in the Hansen solubility parameter space by the central values ​​(δd1, δp1, δh1) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa]. 1 / 2 ] Sphere radius R1 = 3.7 [MPa] 1 / 2 As specified, the second Hansen sphere can be defined in the Hansen solubility parameter space by the central values ​​(δd2, δp2, δh2) = (16.4±0.7, 6.1±1.2, 0.0±2.0) [MPa]. 1 / 2 ], Sphere radius R2 = 10.2 [MPa] 1 / 2 As stipulated.

[0018] Based on the aforementioned composition, as a self-assembled monolayer removal solution, the Hansen solubility parameters are located at the central values ​​(δd1, δp1, δh1) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa]. 1 / 2 ] Sphere radius R1 = 3.7 [MPa] 1 / 2The value lies within the first Hansen sphere as specified and is located at the center value (δd2, δp2, δh2) = (16.4±0.7, 6.1±1.2, 0.0±2.0) [MPa] 1 / 2 ], Sphere radius R2 = 10.2 [MPa] 1 / 2 The removal solution specified in the second Hansen sphere. Therefore, it exhibits not only good solubility but also good wettability for octadecylphosphonic acid monolayers. Thus, compared to conventional substrate processing methods that use only self-assembled monolayer removal solutions with good solubility, it can selectively remove octadecylphosphonic acid monolayers more effectively.

[0019] Furthermore, in the aforementioned configuration, the self-assembled monomolecular membrane removal solution is preferably at least one organic solvent selected from the group consisting of 1-butanol, 2-butanol, 1-pentanol, tetrahydrofuran, and benzyl alcohol.

[0020] To solve the aforementioned problem, the substrate processing apparatus of the present invention is characterized in that it is an apparatus for processing a substrate on which a self-assembled monomolecular film is disposed, comprising: a storage unit for storing a self-assembled monomolecular film removal liquid for selectively removing the self-assembled monomolecular film; a supply unit for supplying the self-assembled monomolecular film removal liquid to the surface of the substrate, thereby selectively removing the self-assembled monomolecular film from the surface of the substrate; and a control unit for controlling the supply of the self-assembled monomolecular film removal liquid to the surface of the substrate; wherein the control unit prepares a liquid in the storage unit as the self-assembled monomolecular film removal liquid, namely, the Hansen solubility parameter of the self-assembled monomolecular film removal liquid is located in the Hansen solubility parameter space with a center value (δd1, δp1, δh1) [MPa]. 1 / 2 ] and sphere radius R1 [MPa 1 / 2 The self-assembled monolayer forming material is located within the first Hansen sphere of the specified material, and is situated in the Hansen solubility parameter space by the central values ​​(δd2, δp2, δh2) [MPa]. 1 / 2 ] and sphere radius R2 [MPa 1 / 2 The second Hansen sphere of the self-assembled monolayer as specified in the diagram.

[0021] According to the aforementioned configuration, the supply unit, under control from the control unit, supplies the self-assembled monomolecular film removal liquid stored in the storage unit to the surface of the substrate. Furthermore, when the self-assembled monomolecular film removal liquid comes into contact with the self-assembled monomolecular film disposed on the substrate surface, it dissolves and removes the self-assembled monomolecular film. Here, the control unit prepares the solution such that the Hansen solubility parameter of the self-assembled monomolecular film removal liquid stored in the storage unit is located within both the first and second Hansen spheres. Therefore, the self-assembled monomolecular film removal liquid supplied to the substrate exhibits not only good solubility for the self-assembled monomolecular film but also good wettability. As a result, according to the aforementioned configuration, for example, a substrate processing apparatus can be provided that can selectively remove self-assembled monomolecular films more effectively compared to conventional substrate processing apparatuses that prepare and supply only a self-assembled monomolecular film removal liquid with good solubility.

[0022] According to the present invention, a self-assembled monomolecular membrane removal liquid capable of selectively and effectively removing self-assembled monomolecular membranes as protective films, and a substrate processing method and substrate processing apparatus using the same are provided. Attached Figure Description

[0023] Figure 1 This is an explanatory diagram showing the Hansen solubility parameters of the self-assembled monolayer removal solution according to an embodiment of the present invention in Hansen solubility parameter space.

[0024] Figure 2 This is a flowchart illustrating an example of the overall process of a substrate processing method according to an embodiment of the present invention.

[0025] Figure 3A This is a schematic diagram illustrating an example of a substrate state change in a film-forming method according to an embodiment of the present invention, showing the case where a material for forming a self-assembled monomolecular film is supplied to the substrate surface.

[0026] Figure 3B This is a schematic diagram illustrating an example of substrate state changes in a film-forming method according to an embodiment of the present invention, showing a case where a self-assembled monomolecular film is formed in a metal film forming region on the substrate surface.

[0027] Figure 3C This is a schematic diagram illustrating an example of substrate state changes in a film-forming method according to an embodiment of the present invention, showing a case where a film is formed in a region on the substrate surface where a metal film is not formed.

[0028] Figure 3D This is a schematic diagram illustrating an example of a substrate state change in a film-forming method according to an embodiment of the present invention, showing a case where the self-assembled monolayer in the metal film formation region on the substrate surface has been removed.

[0029] Figure 4This is a schematic diagram illustrating the supply device in a substrate processing apparatus according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram illustrating the removal apparatus in a substrate processing apparatus according to an embodiment of the present invention. Detailed Implementation

[0031] This invention discovers that by using a liquid with excellent balance between solubility and wettability of SAM as a self-assembled monolayer (SAM) removal solution (hereinafter referred to as "removal solution") for selectively removing self-assembled monolayers (SAM) disposed on a substrate surface, better removal performance than conventional removal solutions is achieved, thus completing this invention. Here, regarding the solubility of SAM, the greater the affinity of the removal solution for the SAM-forming material, the greater the solubility of the SAM. Furthermore, regarding the wettability of SAM, the greater the affinity of the removal solution for SAM, the greater the wettability of the SAM. Moreover, in this invention, the Hansen solubility parameter (HSP) at any temperature is used as an indicator of affinity for SAM or the SAM-forming material.

[0032] HSP is an indicator of the degree of solubility of a solute in a solvent, and can be used to predict the solubility of a solute in a solvent. HSP includes the energy derived from intermolecular dispersion forces (δd), the energy derived from intermolecular dipole interactions (δp), and the energy derived from intermolecular hydrogen bonds (δh), and can be defined by the following formula.

[0033] HSP value (δt) = (δd) 2 +δp 2 +δh 2 ) 1 / 2

[0034] Furthermore, the three parameters δd, δp, and δh can be considered as coordinates in the three-dimensional space (Hansen solubility parameter space) formed by the δd axis, δp axis, and δh axis. In the Hansen solubility parameter space, the solute's (δd) m δp m δh m ) and solvent (δd n δp n δh n The closer the distance between the two molecules, the higher their affinity, indicating that the solute is more easily dissolved in the solvent.

[0035] (Self-assembled monomolecular membrane removal solution)

[0036] Next, refer to the following Figure 1The removal solution of this embodiment will be described. Figure 1 This is an explanatory diagram showing the HSP of the removal liquid of this embodiment in the Hansen solubility parameter space.

[0037] The removal solution of this embodiment can be used to selectively remove SAMs disposed on the surface of a substrate. For example... Figure 1 As shown, the removal solution in this embodiment is its HSP ((δd, δp, δh) [MPa] 1 / 2 The liquid located within the first Hansen sphere 1 and the second Hansen sphere 2 as defined in the Hansen solubility parameter space.

[0038] The first Hansen sphere refers to the Hansen sphere defined by the HSP of the SAM-formed material in the Hansen solubility parameter space. More specifically, such as... Figure 1 As shown, the first Hansen sphere 1 is defined in the Hansen solubility parameter space by the central values ​​(δd1, δp1, δh1) [MPa]. 1 / 2 ] and sphere radius R1 [MPa 1 / 2 The Hansen sphere is defined as specified in the [reference needed]. Furthermore, the second Hansen sphere 2 refers to the Hansen sphere defined by the SAM's HSP in the Hansen solubility parameter space. More specifically, such as... Figure 1 As shown, the second Hansen sphere 2 is defined in the Hansen solubility parameter space by the central values ​​(δd2, δp2, δh2) [MPa]. 1 / 2 ] and sphere radius R2 [MPa 1 / 2 The Hansen sphere is defined as follows. Furthermore, δd, δd1, and δd2 represent the energies originating from intermolecular dispersion forces (dispersion terms). δp, δp1, and δp2 represent the energies originating from dipole interactions of intermolecular forces (polarity terms). δh, δh1, and δh2 represent the energies originating from intermolecular hydrogen bonds (hydrogen bond terms).

[0039] The HSP ((δd, δp, δh) [MPa] of the removal solution in this embodiment 1 / 2 In the Hansen solubility parameter space, it is located within region 3, where the first Hansen sphere 1 and the second Hansen sphere 2 overlap. Therefore, the removal liquid of this embodiment exhibits good affinity for both the SAM forming material and SAM. Thus, the removal liquid not only exhibits good solubility for the SAM forming material but also good wettability for SAM. Therefore, when the removal liquid of this embodiment comes into contact with SAM, it spreads more easily on the SAM surface compared to conventional removal liquids. As a result, for example, compared to conventional removal liquids that only exhibit solubility for SAM, the selective removal performance of SAM is superior.

[0040] Here, the removal liquid in this embodiment is preferably a solvent whose HSP, i.e., (δd, δp, δh) is located at the center C of the circle 4 formed by the intersection of the first Hansen sphere 1 and the second Hansen sphere 2 (refer to...).Figure 1 This solvent exhibits an excellent balance between solubility in SAM-forming materials and wettability in SAM, demonstrating good selective removal performance for SAM. Furthermore, when the first Hansen ball 1 and the second Hansen ball 2 are in contact, the values ​​(δd, δp, δh) of the removal liquid are preferably values ​​located at the tangent point between them.

[0041] The removal liquid in this embodiment is not particularly limited as long as its HSP lies within the region 3 where the first Hansen sphere 1 and the second Hansen sphere 2 overlap in the Hansen solubility parameter space. Specifically, as a removal liquid, at least one organic solvent selected from the group consisting of 1-butanol, 2-butanol, 1-pentanol, tetrahydrofuran (THF), and benzyl alcohol can be used. The removal liquid can be appropriately selected and used in combination with these organic solvents depending on the type of SAM. Furthermore, the removal liquid in this embodiment is preferably a liquid that does not exhibit solubility for metal films and membranes (described in detail below). Alternatively, if it does exhibit solubility, it is preferable that the degree is such that it does not cause poor film formation such as excessive etching of metal films and membranes.

[0042] For example, in the case of SAM containing an octadecylphosphonic acid monolayer, the first Hansen sphere 1 associated with the HSP (25°C) of octadecylphosphonic acid is determined by the central values ​​(δd1, δp1, δh1) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa]. 1 / 2 ] Sphere radius R1 = 3.7 [MPa] 1 / 2 The specified value is δt1 = 3.7 MPa. 1 / 2 Additionally, the second Hansen sphere 2 associated with the HSP (25°C) of the octadecylphosphonic acid monolayer is determined by the central values ​​(δd2, δp2, δh2) = (16.4 ± 0.7, 6.1 ± 1.2, 0.0 ± 2.0) [MPa]. 1 / 2 ], Sphere radius R2 = 10.2 [MPa] 1 / 2 The specified value is δt2 = 10.2 MPa. 1 / 2 Therefore, the most suitable removal solution for selectively removing octadecylphosphonic acid monolayers is considered to be a solvent with HSP (δd, δp, δh) = (16.8, 5.6, 9.0). Examples of removal solutions that achieve these (δd, δp, δh) values ​​include: a mixed solvent containing THF, 1-butanol, and benzyl alcohol (volume ratio: THF:1-butanol:benzyl alcohol = 8:1:1); a mixed solvent containing THF, 2-butanol, and benzyl alcohol (volume ratio: THF:2-butanol:benzyl alcohol = 8:1:1); and a mixed solvent containing THF, 1-pentanol, and benzyl alcohol (volume ratio: THF:1-pentanol:benzyl alcohol = 8:1:1).

[0043] Furthermore, the HSP of the illustrated organic solvent is described below.

[0044] [Table 1]

[0045]

[0046] (Substrate processing method)

[0047] Next, refer to the following Figure 2 and Figures 3A-3D The substrate processing method of this embodiment will be described. Figure 2 This is a flowchart illustrating an example of the overall process of a substrate processing method according to an embodiment of the present invention. Figures 3A-3D This is a schematic diagram illustrating an example of substrate state changes in a film-forming method according to an embodiment of the present invention. Figure 3A This illustrates the process of supplying a material for forming a self-assembled monolayer to the surface of a substrate. Figure 3B This illustrates a case where a self-assembled monolayer is formed in the metal film formation region on the substrate surface. Figure 3C This illustrates a case where a film is formed in a region on the substrate surface where a metal film is not formed. Figure 3D This shows the case where the self-assembled monolayer in the metal film formation region on the substrate surface has been removed.

[0048] The substrate processing method of this embodiment provides a technique for selectively forming a film on the surface of a substrate W according to the material of the substrate surface. Furthermore, in this specification, "substrate" refers to various substrates such as semiconductor substrates, photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED (Field Emission Display) substrates, optical disc substrates, magnetic disk substrates, and magneto-optical disc substrates.

[0049] like Figure 2 As shown, the substrate processing method of this embodiment includes at least: a substrate W preparation step S101, a self-assembled monomolecular film formation step S102 for forming SAM, a film formation step S103, a removal liquid preparation step S104, and a SAM removal step S105.

[0050] like Figure 2 and Figure 3AAs shown, the substrate W prepared by the preparation step S101 includes: a metal film forming region formed by the exposure of the metal film 11, and a metal film non-forming region formed by the exposure of the insulating film 12. More specifically, the substrate W may be, for example, a substrate having an insulating film 12 and a metal film 11, wherein the insulating film 12 is formed with trenches having arbitrary wiring widths, and the metal film 11 is embedded in the trenches. Furthermore, the preparation step of the substrate W may include, for example, moving the substrate W into the interior of a container, i.e., a chamber (described in detail below), that houses the substrate W using a substrate loading and unloading mechanism.

[0051] Figure 3A In this process, one metal film forming region and one metal film non-forming region are formed, but multiple regions can also be formed. For example, the strip-shaped metal film non-forming region can be configured to be located between adjacent strip-shaped metal film forming regions, or the strip-shaped metal film forming region can be configured to be located between adjacent strip-shaped metal film non-forming regions.

[0052] Furthermore, the substrate W in this embodiment is not limited to having only metal film forming regions and non-metal film forming regions on its surface. For example, regions formed by other films exposed on the surface may also be provided, and these other films may contain materials different from the metal film 11 and the insulating film 12. In this case, the location of these regions is not particularly limited and can be arbitrarily set.

[0053] The metal film 11 is not particularly limited, and examples include metal films containing copper (Cu), tungsten (W), ruthenium (Ru), germanium (Ge), silicon (Si), titanium nitride (TiN), cobalt (Co), molybdenum (Mo), etc.

[0054] Furthermore, the insulating film 12 is not particularly limited, and examples include insulating films containing silicon oxide (SiO2), hafnium oxide (HfO2), zirconium oxide (ZrO2), silicon nitride (SiN), etc.

[0055] The processing liquid used in the SAM forming process S102 contains at least the material that forms SAM (hereinafter referred to as "SAM forming material") and a solvent. The SAM forming material can be dissolved in the solvent or dispersed in the solvent.

[0056] There are no particular limitations on the materials used to form SAMs; examples include phosphonic acid compounds with phosphonic acid groups, such as monophosphonic acid and diphosphonic acid. These phosphonic acid compounds can be used alone or in combination of two or more.

[0057] Monophosphonic acids are not particularly limited; for example, phosphonic acid compounds represented by the general formula RP(=O)(OH)2 (where 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) can be listed. Furthermore, in this specification, when a carbon number range is expressed, the range refers to all integer carbon numbers included in the range. Therefore, for example, "alkyl group having 1 to 3 carbon atoms" refers to all alkyl groups having 1, 2, and 3 carbon atoms.

[0058] Alkyl groups, represented by carbon atoms from 1 to 18, can be either straight-chain or branched. Further, the carbon number of the alkyl group is preferably in the range of 10 to 18, more preferably in the range of 14 to 18. Additionally, alkyl groups having fluorine atoms within the range of 1 to 18 carbon atoms can be either straight-chain or branched. Further, the carbon number of the alkyl group having fluorine atoms is preferably in the range of 10 to 18, more preferably in the range of 14 to 18.

[0059] Furthermore, as a monophosphonic acid represented by RP(=O)(OH)2, specifically, for example, compounds represented by any of the following chemical formulas (1) to (16) can be listed.

[0060] [Chemical Formula 1]

[0061]

[0062] In addition, as a monophosphonic acid, in addition to the compounds exemplified above, compounds represented by any of the following chemical formulas (17) to (19) may also be used.

[0063] [Chemical Formula 2]

[0064]

[0065] As diphosphonic acids, compounds represented by either of the following chemical formulas (20) and (21) can be listed.

[0066] [Chemical Formula 3]

[0067]

[0068] Among the phosphonic acid compounds exemplified, octadecylphosphonic acid and the like are preferred from the viewpoint of forming dense SAM.

[0069] The solvent in the treatment solution is not particularly limited, and examples include alcohol solvents, ether solvents, glycol ether solvents, and glycol ester solvents. Alcohol solvents are not particularly limited, and examples include ethanol. Ether solvents are not particularly limited, and examples include tetrahydrofuran (THF). Glycol ether solvents are not particularly limited, and examples include propylene glycol monomethyl ether (PGME). Glycol ester solvents are not particularly limited, and examples include propylene glycol monomethyl ether acetate (PGMEA). These solvents can be used alone or in mixtures of two or more. Furthermore, these solvents can be used in any combination with the phosphonic acid compounds described above. Of the solvents described, from the viewpoint of being able to dissolve the phosphonic acid compounds, alcohol solvents are preferred, and ethanol is particularly preferred.

[0070] The content of SAM forming material 13 relative to the total mass of the treatment liquid is preferably in the range of 0.0004% to 0.2% by mass, more preferably in the range of 0.004% to 0.08% by mass, and particularly preferably in the range of 0.02% to 0.06% by mass.

[0071] In addition, the treatment solution may contain known additives, within a range that does not hinder the effects of the present invention. The additives are not particularly limited; examples include stabilizers and surfactants.

[0072] like Figure 2 , Figure 3A and Figure 3B As shown, the SAM formation process S102 is as follows: the processing solution is brought into contact with the surface of the substrate W, and the SAM forming material 13 contained in the processing solution is adsorbed onto the surface of the metal film 11, thereby forming SAM 14. Here, SAM 14 is selectively formed only on the metal film 11 in the metal film formation area of ​​the substrate W, and not in the non-metal film formation area. The reason why SAM 14 is formed only on the metal film 11 is that, for example, when the metal film 11 is a Cu (copper) film, the phosphonic acid groups of the phosphonic acid compound, which is the SAM forming material 13, react with the -OH groups on the surface of the Cu film as shown in the following chemical reaction formula.

[0073] [Chemical Formula 4]

[0074]

[0075] There is no particular limitation on the method of bringing the treatment liquid into contact with the substrate W. Examples include: coating the treatment liquid onto the surface of the substrate W, spraying the treatment liquid onto the surface of the substrate W, immersing the substrate W in the treatment liquid, etc.

[0076] One method for applying a processing liquid to the surface of a substrate W is as follows: While the substrate W is rotating at a certain speed around its central axis, the processing liquid is supplied to the central portion of the substrate W's surface. As a result, the processing liquid supplied to the substrate W's surface flows from near the center of the substrate W's surface to the periphery of the substrate W due to the centrifugal force generated by the substrate W's rotation, thereby diffusing to the entire surface of the substrate W. Consequently, the entire surface of the substrate W is covered by the processing liquid, forming a liquid film of the processing liquid.

[0077] The SAM formation process S102 can, for example, be carried out in an inert gas environment.

[0078] In the SAM formation process S102, a step may be included to remove the processing liquid remaining on the surface of the substrate W. The process for removing the processing liquid is not particularly limited; for example, a step may be included where the processing liquid is removed by centrifugal force through rotating the substrate W at a certain speed.

[0079] In addition, when performing the process of centrifugally removing the treatment liquid, the rotation speed of the substrate W is only required to remove the treatment liquid sufficiently and is not particularly limited. It 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.

[0080] like Figure 2 and Figure 3C As shown, the film formation process S103 is a process in which the target film 15 is formed on the insulating film 12 in the non-metal film formation region. At this time, the SAM14 formed in the metal film formation region functions as a protective film for the metal film 11, thus enabling the target film 15 to be selectively formed in the non-metal film formation region.

[0081] The target film 15 is not particularly limited, and examples include films containing alumina (Al2O3), cobalt oxide (CoO), or zirconium oxide (ZrO2). Furthermore, the method for forming these films 15 is not particularly limited, and examples include: CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), vacuum evaporation, sputtering, deposition, thermal CVD, and thermal ALD.

[0082] The preparation step S104 of the removal liquid is a step in which the removal liquid is prepared by performing the following operations: preparing the removal liquid such that its HSP is located within the first Hansen sphere 1 of the SAM forming material 13 and within the second Hansen sphere 2 of the SAM 14, etc. This preparation step S104 of the removal liquid is performed at least before the removal step S105 of the SAM 14 described below.

[0083] The first Hansen sphere 1 of the SAM forming material 13 can be determined as follows: First, in a Hansen solubility parameter space specified by plotting (δd, δp, δh) in three-dimensional space, a graph is plotted for various known organic solvents (excluding the case of mixed solvents of two or more). Next, a solubility test of the SAM forming material 13 in each organic solvent is performed. Based on the results of this test, each organic solvent is evaluated as a good solvent or a bad solvent for the SAM forming material 13. Here, a good solvent is an organic solvent with better solubility or wettability than a bad solvent. Thus, the Hansen sphere containing the good solvent and not the bad solvent, and having the smallest radius, is designated as the first Hansen sphere 1. Further, based on the designated first Hansen sphere 1, the sphere radius R1 and the center values ​​(δd1, δp1, δh1) are determined.

[0084] Furthermore, the second Hansen sphere 2 of SAM14 can be determined as follows: First, in the Hansen solubility parameter space specified by plotting (δd, δp, δh) in three-dimensional space, a graph is plotted for various known organic solvents (excluding mixtures of two or more solvents) with (δd, δp, δh). Next, droplets of each organic solvent are brought into contact with the surface of SAM14, and the contact angle is measured to perform a wettability test. Further, after measuring the contact angle, it is confirmed whether there are solvent traces of organic solvents on the surface of SAM14. Then, based on the measured contact angle and the presence or absence of solvent traces, it is determined whether each organic solvent is a good or bad solvent for SAM14. Thus, the Hansen sphere containing good solvents and not bad solvents, and having the smallest radius, is designated as the second Hansen sphere 2. Further, based on the designated second Hansen sphere 2, the sphere radius R2 and the center values ​​(δd2, δp2, δh2) are determined.

[0085] Next, a removal solution is prepared. The removal solution can be prepared by mixing two or more organic solvents so that the HSP is located in region 3, which overlaps with the first Hansen sphere 1 and the second Hansen sphere 2, in the Hansen solubility parameter space. Alternatively, an organic solvent can be selected that allows the HSP to be located in region 3 using only one solvent. Furthermore, the mixing ratio when mixing two or more organic solvents is not particularly limited and can be appropriately set according to the HSP content of the organic solvents used.

[0086] like Figure 2 and Figure 3D As shown, the removal step S105 is a step that removes SAM14 formed in the metal film formation area after the film 15 formation step. In this step, the removal of SAM14 is carried out by bringing the removal solution into contact with the SAM14 at least once. Thus, as... Figure 3DAs shown, a substrate W in which the film 15 is selectively formed only in areas where the metal film is not formed, and the metal film 11 is exposed, can be obtained. Here, the removal of SAM14 includes both the case where SAM14 is dissolved and removed by the removal liquid, and the case where SAM14 is detached (peeled) from the substrate W. Furthermore, even when SAM14 is peeled from the substrate W, the removal liquid of this embodiment exhibits good solubility for the SAM forming material 13, and therefore, the peeled SAM14 can also be dissolved. Thus, in this embodiment, it is possible to prevent or reduce the residue of peeled SAM14 remaining on the surface of the substrate W.

[0087] There are no particular limitations on the method of bringing the removal liquid into contact with SAM14. Examples include: applying the removal liquid to the surface of the substrate W, spraying the removal liquid onto the surface of the substrate W, or immersing the substrate W in the removal liquid.

[0088] One method for applying the removal liquid to the surface of the substrate W is as follows: While the substrate W is rotating at a certain speed around its central axis, the removal liquid is supplied to the central portion of the substrate W's surface. As a result, the removal liquid supplied to the substrate W's surface flows from near the center of the substrate W's surface to the periphery of the substrate W due to the centrifugal force generated by the substrate W's rotation, thereby diffusing to the entire surface of the substrate W. Consequently, the entire surface of the substrate W is covered with the removal liquid, forming a liquid film of the removal liquid.

[0089] The removal process S105 can be carried out, for example, in an inert gas environment.

[0090] The removal process S105 may include a process of removing the removal liquid remaining on the surface of the substrate W. The removal process is not particularly limited; for example, a process of rotating the substrate W at a certain speed to remove the removal liquid using centrifugal force may be included.

[0091] In addition, when performing the process of removing the removal liquid by centrifugal force, the rotation speed of the substrate W is only required to remove the removal liquid sufficiently and is not particularly limited. It 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.

[0092] As described above, according to the substrate processing method of this embodiment, by using a solvent in which the HSP is located within the first Hansen sphere 1 defined by the HSP of the SAM forming material 13 and within the second Hansen sphere 2 defined by the HSP of the SAM 14 as a removal liquid, the etching of the metal film 11 can be suppressed compared with conventional removal liquids, and the SAM 14 can be removed selectively and effectively.

[0093] (Substrate processing apparatus)

[0094] Next, based on Figure 4 and Figure 5 The substrate processing apparatus of this embodiment will be described. Figure 4 This is an explanatory diagram showing the supply device for the removal liquid in the substrate processing apparatus of this embodiment. Figure 5 This is an explanatory diagram showing the removal apparatus of the substrate processing apparatus of this embodiment.

[0095] like Figure 4 As shown, the substrate processing apparatus of this embodiment includes at least: a supply device 100 for supplying a removal liquid, a removal device 200 for removing SAM14, and a control unit 300 for controlling each part of the substrate processing apparatus.

[0096] [Supply device]

[0097] like Figure 4 As shown, the supply device 100 of this embodiment has the function of supplying the removal device 200 with a removal liquid for removing SAM14, and the supply device 100 includes a removal liquid tank (storage unit) 101, a temperature adjustment unit 102, and a supply pipe 103.

[0098] The removal liquid tank 101 may also include a stirring unit (not shown) for stirring the removal liquid within the tank 101, and a temperature adjustment unit 102 for adjusting the temperature of the removal liquid within the tank 101. As the stirring unit, a mechanism may include a rotating unit for stirring the removal liquid within the tank 101, and a stirring control unit for controlling the rotation of the rotating unit. The stirring control unit is electrically connected to the control unit 300, and the rotating unit, for example, has propeller-shaped stirring blades at the lower end of its rotating shaft. By issuing an operation command to the stirring control unit from the control unit 300, the rotating unit is rotated, thereby stirring the removal liquid using the stirring blades. As a result, the concentration and temperature of the removal liquid can be made uniform within the removal liquid tank 101.

[0099] The supply pipe 103 is connected to the removal liquid tank 101. Furthermore, a valve 103a is installed along the middle of the supply pipe 103. The valve 103a is electrically connected to the control unit 300, and its opening and closing can be controlled by the operation command of the control unit 300. If the valve 103a is opened by the operation command of the control unit 300, the removal liquid can be supplied to the removal device 200.

[0100] Additionally, the supply device 100 includes a first organic solvent tank 104 for storing a first organic solvent and a second organic solvent tank 105 for storing a second organic solvent. The first organic solvent tank 104 is connected to a first discharge pipe 104a for supplying the first organic solvent to the removal liquid tank 101. Furthermore, a first valve 104b is provided along the middle path of the first discharge pipe 104a. The first valve 104b is electrically connected to the control unit 300 and can be controlled to open or close via an operation command from the control unit 300. If the first valve 104b is opened via an operation command from the control unit 300, a predetermined amount of the first organic solvent for preparing the removal liquid is supplied to the removal liquid tank 101. Furthermore, the first organic solvent tank 104 may also include a stirring unit for stirring the stored first organic solvent and a temperature adjustment unit for adjusting the temperature of the first organic solvent (both not shown). As the stirring unit, the same component as the stirring unit that can be provided in the removal liquid tank 101 can be used.

[0101] Additionally, a second discharge pipe 105a for supplying the second organic solvent to the removal liquid tank 101 is also connected to the second organic solvent tank 105. Furthermore, a second valve 105b is provided along the intermediate path of the second discharge pipe 105a. The second valve 105b is electrically connected to the control unit 300 and can be controlled by an operation command from the control unit 300. If the second valve 105b is opened by an operation command from the control unit 300, a predetermined amount of the second organic solvent used to prepare the removal liquid is supplied to the removal liquid tank 101. Furthermore, the second organic solvent tank 105 may, similarly to the first organic solvent tank 104, include a stirring unit for stirring the stored second organic solvent and a temperature adjustment unit for adjusting the temperature of the second organic solvent (both not shown).

[0102] By controlling the opening and closing of the first valve 104b and the second valve 105b respectively using the operation commands of the control unit 300, the supply amount or supply time of the first organic solvent and the second organic solvent can be adjusted. As a result, the first organic solvent and the second organic solvent are supplied to the removal liquid tank 101 in a predetermined mixing ratio, and the desired removal liquid can be prepared.

[0103] Furthermore, this embodiment uses the example of preparing the removal liquid using two organic solvents, but the present invention is not limited to this method. For example, when using a removal liquid composed of one organic solvent, the second organic solvent tank 105 or the second discharge pipe 105a and the second valve 105b can be omitted. In addition, when using three or more organic solvents, organic solvent tanks, discharge pipes and valves with the same configuration can be further provided.

[0104] [Removal Device]

[0105] Next, based on Figure 5 The removal device 200 will be described below.

[0106] The removal device 200 of this embodiment is a single-piece removal device capable of removing SAM14 formed on the metal film 11.

[0107] like Figure 5 As shown, the removal device 200 includes at least: a substrate holding section 210 for holding the substrate W, a supply section 220 for supplying removal liquid to the surface Wf of the substrate W, a chamber 230 serving as a container for holding the substrate W, and a spill-proof shield 240 for capturing the removal liquid. Additionally, the removal device 200 may also include a loading / unloading mechanism (not shown) for loading or unloading the substrate W.

[0108] The substrate holding section 210 is a mechanism for holding the substrate W, such as... Figure 4 As shown, the substrate holding part 210 holds the substrate W in a generally horizontal orientation with the substrate surface Wf facing upwards and rotates it. The substrate holding part 210 has a rotating chuck 211 integrally formed with a rotating base 212 and a rotating support shaft 213. The rotating base 212 has a generally circular shape when viewed from above, and a hollow rotating support shaft 213 extending in a generally vertical direction is fixed to its center. The rotating support shaft 213 is connected to the rotating shaft of a chuck rotating mechanism 214 containing a motor. The chuck rotating mechanism 214 is housed within a cylindrical housing 215, which supports the rotating support shaft 213 in a manner that allows it to rotate freely around the vertical rotating shaft.

[0109] The chuck rotation mechanism 214 can rotate the rotary support shaft 213 around the rotation axis by being driven by the chuck drive unit (not shown) from the control unit 300. Consequently, the rotary base 212, mounted on the upper end of the rotary support shaft 213, rotates around the rotation axis J. The control unit 300 can control the chuck rotation mechanism 214 via the chuck drive unit, thereby adjusting the rotation speed of the rotary base 212.

[0110] Near the periphery of the rotating base 212, a plurality of clamping pins 216 are erected to hold the peripheral end of the substrate W. The number of clamping pins 216 is not particularly limited, but to reliably hold the circular substrate W, at least three are preferably provided. In this embodiment, three are arranged at equal intervals along the periphery of the rotating base 212. Each clamping pin 216 includes a substrate support pin and a substrate holding pin. The substrate support pin supports the periphery of the substrate W from below, and the substrate holding pin presses against the outer peripheral end face of the substrate W supported by the substrate support pin to hold the substrate W.

[0111] The supply unit 220 is positioned above the substrate holding unit 210 and supplies the removal liquid supplied from the supply device 100 onto the surface Wf of the substrate W. The supply unit 220 has a nozzle 221 and an arm 222. The nozzle 221 is mounted on the front end of the horizontally extending arm 222 and is positioned above the rotating base 212 when the removal liquid is sprayed out.

[0112] The supply unit 220 further includes a supply unit lifting mechanism 224. The supply unit lifting mechanism 224 is connected to the arm 222.

[0113] The supply unit lifting mechanism 224 is electrically connected to the control unit 300 and can raise and lower the supply unit 220 according to the operation command from the control unit 300. As a result, the nozzle 221 of the supply unit 220 can be brought closer to or away from the substrate W held by the substrate holding unit 210, and the distance between the nozzle and the surface Wf of the substrate W can be adjusted.

[0114] Furthermore, when the substrate W is moved into or out of the removal device 200, the supply unit lifting mechanism 224 is activated based on the operation command of the control unit 300, causing the supply unit 220 to rise. As a result, the nozzle 221 can be spaced at a certain distance from the surface Wf of the substrate W, making it easy to move the substrate W in and out.

[0115] The anti-splash shield 240 is provided to surround the rotating base 212. The anti-splash shield 240 is connected to a lifting drive mechanism (not shown) and can move up and down. When the removal liquid is supplied to the surface Wf of the substrate W, the lifting drive mechanism positions the anti-splash shield 240 to a predetermined position, surrounding the substrate W held by the clamping pin 216 from the side. This allows the removal liquid that splashes out from the substrate W or the rotating base 212 to be captured.

[0116] The above description uses the case where the removal device in the substrate processing apparatus of the present invention processes one substrate W at a time as an example. However, the substrate processing apparatus of the present invention is not limited to this method, and can also be applied to other methods of the substrate processing apparatus of the present invention, namely, a batch processing method in which the removal device processes multiple substrates at a time.

[0117] [Control Department]

[0118] The control unit 300 is electrically connected to each part of the substrate processing apparatus and controls the operation of each part. The control unit 300 is a computer comprising an arithmetic unit and a storage unit. The arithmetic unit uses a CPU (central processing unit) to perform various arithmetic operations. The storage unit includes: a read-only memory (ROM) for storing substrate processing programs, a random access memory (RAM) for storing various information, and a disk pre-stored with control software or data. The disk pre-stores data related to substrate processing conditions. These substrate processing conditions include, for example, the supply conditions of a first organic solvent and a second organic solvent designed to achieve a specified HSP for the removal liquid based on the type of SAM14, or the supply conditions of the removal liquid to the substrate W. The CPU reads the substrate processing conditions into the RAM and controls each part of the substrate processing apparatus based on this content.

[0119] (Other matters)

[0120] The supply or removal device of this embodiment can be used in various devices other than substrate processing devices, or it can be used alone.

[0121] The foregoing description has outlined the most suitable embodiments of the present invention. However, the present invention is not limited to these embodiments. The components in the embodiments and variations can be modified, altered, substituted, added to, deleted from, and combined without contradiction.

[0122] Hereinafter, suitable embodiments of the present invention will be described in detail by way of example. However, unless otherwise specified, the scope of the present invention is not limited to the materials, quantities, conditions, etc., described in these embodiments.

[0123] (Example 1)

[0124] [Preparation of the treatment solution]

[0125] Octadecylphosphonic acid (CH3(CH2)) is used as a SAM forming material. 17 P(=O)(OH)2) was dissolved in ethanol solvent to prepare the treatment solution of this embodiment. The concentration of octadecylphosphonic acid was 0.04% by mass relative to the total mass of the treatment solution.

[0126] [Preparation steps for the removal solution]

[0127] 1. Designation of the first Hansen ball

[0128] First, determine the first Hansen sphere for octadecylphosphonic acid (powder). That is, prepare the solvents shown in Table 2 below as known organic solvents (δd, δp, δh), and plot them in the Hansen solubility parameter space specified by drawing (δd, δp, δh) in three-dimensional space.

[0129] Next, the solubility of octadecylphosphonic acid (powder) in various organic solvents was tested. Specifically, 1 mg of octadecylphosphonic acid powder was added to 1 mL of each of the organic solvents shown in Table 2 to confirm the solubility of the octadecylphosphonic acid powder. Furthermore, the tests were conducted at 25°C. The solubility of the octadecylphosphonic acid powder was determined according to the following criteria.

[0130] 1: There was no residue of octadecylphosphonic acid powder after dissolution, and the solution showed no fluctuations.

[0131] 2: Although there was no residue of octadecylphosphonic acid powder dissolved, the solution fluctuated.

[0132] 3: Octadecylphosphonic acid powder has dissolved residue.

[0133] [Table 2]

[0134]

[0135] Based on the results in Table 2, each organic solvent was evaluated as either a good or bad solvent for octadecylphosphonic acid powder. Here, a good solvent is an organic solvent with better solubility or wettability than a bad solvent. Based on this evaluation, the Hansen sphere with the smallest radius that contains a good solvent but no bad solvent was designated as the first Hansen sphere. Furthermore, based on the designated first Hansen sphere, the center values ​​(δd1, δp1, δh1) and the sphere radius R1 were calculated. The results are: (δd1, δp1, δh1) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa] 1 / 2 The radius of the sphere is R1 = 3.7 MPa. 1 / 2 ].

[0136] 2. Designation of the second Hansen ball

[0137] Then, the second Hansen sphere of the octadecylphosphonic acid monolayer is determined. That is, the solvents shown in Table 3 below are prepared as known organic solvents (δd, δp, δh), and plotted in the Hansen solubility parameter space specified by plotting (δd, δp, δh) in three-dimensional space.

[0138] Next, a wettability test was conducted by contacting droplets of each organic solvent with the surface of the octadecylphosphonic acid monolayer to measure the contact angle. Specifically, each organic solvent shown in Table 3 was dropped onto the octadecylphosphonic acid monolayer, and the contact angle was measured. A contact angle meter (trade name: Drop Master 501, manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the contact angle. The results are shown in Table 3. Furthermore, after measuring the contact angle, it was confirmed whether there were any traces of organic solvent on the surface of the octadecylphosphonic acid monolayer. No traces of solvent were detected in any of the organic solvents.

[0139] Based on the contact angle measurements and solvent traces in Table 3, the effectiveness of each organic solvent in determining whether it is a good or bad solvent for the octadecylphosphonic acid monolayer was evaluated. Based on this evaluation, the Hansen sphere with the smallest radius, containing only a good solvent and no bad solvent, was designated as the second Hansen sphere. Furthermore, based on the designated second Hansen sphere, the center values ​​(δd², δp², δh²) and the sphere radius R² were calculated. The results showed that the center values ​​(δd², δp², δh²) = (16.4 ± 0.7, 6.1 ± 1.2, 0.0 ± 2.0) [MPa]. 1 / 2 The radius of the sphere is R2 = 10.2 MPa. 1 / 2 ].

[0140] [Table 3]

[0141]

[0142] 3. Preparation of the removal solution

[0143] Based on the first Hansen sphere of octadecylphosphonic acid and the second Hansen sphere of the octadecylphosphonic acid monolayer, the values ​​(δd, δp, δh) located at the center of the circle formed by the intersection of these Hansen spheres were identified. The results showed that the most suitable removal solution for removing the octadecylphosphonic acid monolayer was an HSP with (δd, δp, δh) = (16.8, 5.6, 9.0) [MPa]. 1 / 2 ]、δt=19.9[MPa 1 / 2 [The liquid.]

[0144] Furthermore, based on this result, THF was selected as the removal solution in this embodiment. The HSP of THF is (δd, δp, δh) = (16.8, 5.7, 8.0) [MPa] 1 / 2 ]、δt=19.5[MPa 1 / 2 ].

[0145] [SAM formation process and film formation process]

[0146] Using the aforementioned processing solution, SAM is formed on the substrate surface. Specifically, firstly, a substrate is prepared as follows (substrate preparation step S101): the substrate has an interlayer insulating film containing a SiO2 film (film thickness 200nm), and a trench with a wiring width of 100nm is formed on the interlayer insulating film, and a Cu film (film thickness 200nm) as a metal film is embedded in the trench.

[0147] Next, the processing solution is coated on the surface of the substrate, so that octadecylphosphonic acid is adsorbed onto the Cu film to form SAM (SAM formation process S102).

[0148] Furthermore, an aluminum oxide (Al2O3) film was formed on a SiO2 film using the ALD method with H2O as the oxidant. Specifically, an organometallic layer of Al was deposited at an atomic level, and then the Al was oxidized using the oxidant to form an Al2O3 thin film. This process was repeated 72 times. As a result, an Al2O3 film with a thickness of 5 nm was formed.

[0149] [SAM Removal Process]

[0150] Then, a removal solution is supplied to the surface of the substrate, bringing the removal solution into contact with the SAM on the Cu film, thereby removing the SAM. This process is used to prepare the sample of this embodiment.

[0151] (Example 2)

[0152] In this embodiment, 2-butanol was used instead of THF as the removal solution. Otherwise, the sample for this embodiment was prepared in the same manner as in Example 1.

[0153] (Example 3)

[0154] In this embodiment, benzyl alcohol was used instead of THF as the removal solution. Otherwise, the sample of this embodiment was prepared in the same manner as in Example 1.

[0155] (Example 4)

[0156] In this embodiment, 1-pentanol was used instead of THF as the removal solution. Otherwise, the sample of this embodiment was prepared in the same manner as in Example 1.

[0157] (Example 5)

[0158] In this embodiment, 1-butanol was used instead of THF as the removal solution. Otherwise, the sample for this embodiment was prepared in the same manner as in Example 1.

[0159] (Example 6)

[0160] In this embodiment, a mixed solvent containing THF, 2-butanol, and benzyl alcohol was used instead of THF as the removal liquid. Furthermore, the mixing ratio of THF, 2-butanol, and benzyl alcohol, by volume, was THF:2-butanol:benzyl alcohol = 8:1:1. Otherwise, the sample of this embodiment was prepared in the same manner as in Example 1.

[0161] (Example 7)

[0162] In this embodiment, a mixed solvent containing THF, 1-butanol, and benzyl alcohol was used instead of THF as the removal liquid. Furthermore, the mixing ratio of THF, 1-butanol, and benzyl alcohol, by volume, was THF:1-butanol:benzyl alcohol = 8:1:1. Otherwise, the sample of this embodiment was prepared in the same manner as in Example 1.

[0163] (Example 8)

[0164] In this embodiment, a mixed solvent containing THF, 1-pentanol, and benzyl alcohol was used instead of THF as the removal liquid. Furthermore, the mixing ratio of THF, 1-pentanol, and benzyl alcohol, by volume, was THF:1-pentanol:benzyl alcohol = 8:1:1. Otherwise, the sample of this embodiment was prepared in the same manner as in Example 1.

[0165] (Performance evaluation removed)

[0166] For each sample in Examples 1-8, the extent to which etching of the Cu film was suppressed before and after SAM removal was confirmed. Specifically, the film thickness of the Cu film before and after SAM removal was measured by transmission electron microscopy (TEM), and the reduction in Cu film thickness was calculated. The results are shown in Table 4. As can be seen from Table 4, in all samples of Examples 1-8, the reduction in Cu film thickness was successfully suppressed to less than 3 nm relative to the initial film thickness of 200 nm. This confirms that the removal solutions used in Examples 1-8 can remove SAM while suppressing Cu film etching as much as possible, demonstrating excellent selective removal performance.

[0167] Furthermore, for each sample in Examples 1 and 6, the residual ratio of Al atoms on the Cu film after SAM removal was confirmed. Specifically, for each sample, cross-sectional images were observed using TEM, and elemental analysis of the observed area was performed using energy-dispersive X-ray spectroscopy (EDX). The elemental analysis using EDX focused on Al atoms on both the Al2O3 and Cu films. The residual ratio of Al atoms on the Cu film was calculated based on the following formula. The results are shown in Table 4.

[0168] (Residual Al atom ratio) = (Amount of Al atoms on Cu film) / (Amount of Al atoms in Al2O3 film) × 100 (%)

[0169] In the sample of Example 6, the residual Al atom ratio was successfully suppressed to below 10%. Due to the formation of the Al2O3 film, Al atoms still remain in the SAM. Therefore, the less residual Al atoms remain on the Cu film after SAM removal, the better the selective removal of SAM from the Cu film can be considered. In the sample of Example 6, the residual Al atom ratio on the Cu film was suppressed; therefore, it can be said that the removal solution used in Example 6 is excellent in SAM removal.

[0170] [Table 4]

[0171]

Claims

1. Use of a self-assembled monolayer removal liquid for removing a self-assembled monolayer containing octadecylphosphonic acid, the self-assembled monolayer removal liquid being used for selectively removing a self-assembled monolayer provided on a surface of a substrate, and The self-assembled monolayer removing liquid has a Hansen solubility parameter located within a first Hansen sphere of the self-assembled monolayer-forming material defined on a Hansen solubility parameter space by a center value (δd1, δp1, δh1) [MPa 1 / 2 ] and a sphere radius R1 [MPa 1 / 2 ]. Further, in the second Hansen sphere defined by the center value (δd2, δp2, δh2) [MPa 1 / 2 ] and the sphere radius R2 [MPa 1 / 2 ] of the self-assembled monolayer, the material for forming the self-assembled monolayer being octadecylphosphonic acid, the self-assembled monolayer containing a monolayer of the octadecylphosphonic acid, The first Hansen sphere is defined in the Hansen solubility parameter space by the center values (d di, d pi, d hi) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa 1 / 2 ] and the sphere radius R1= 3.7 [MPa 1 / 2 ]. The 2nd Hansen sphere is defined in the Hansen solubility parameter space by the center values (d2, dP2, dh2) = (16.4 ± 0.7, 6.1 ± 1.2, 0.0 ± 2.0) [MPa 1 / 2 ] and the sphere radius R2= 10.2 [MPa 1 / 2 ]. the self-assembled monolayer removal liquid being any one of the following (1) to (4) organic solvents: (1) at least one organic solvent selected from the group consisting of 1-butanol, 2-butanol, 1-pentanol, and benzyl alcohol; (2) an organic solvent containing tetrahydrofuran, 1-butanol, and benzyl alcohol; (3) an organic solvent containing tetrahydrofuran, 2-butanol, and benzyl alcohol; (4) an organic solvent containing tetrahydrofuran, 1-pentanol, and benzyl alcohol.

2. The use of a self-assembled monolayer removal liquid for removing a self-assembled monolayer containing octadecylphosphonic acid according to claim 1, wherein the Hansen solubility parameter of the self-assembled monolayer removal liquid is a value located at the center of a circle formed by the intersection of the first Hansen sphere and the second Hansen sphere, or a value located at a tangent point of the first Hansen sphere and the second Hansen sphere.

3. A substrate processing method which is a method of processing a substrate on the surface of which a self-assembled monolayer is provided, the method comprising: a preparation step of preparing a self-assembled monolayer removal liquid for selectively removing the self-assembled monolayer from the substrate; and a removal step of bringing the self-assembled monolayer removal liquid into contact with the self-assembled monolayer, thereby selectively removing the self-assembled monolayer from the substrate; and the preparation step is a step of preparing a self-assembled monolayer removal liquid in which The Hansen solubility parameter of the self-assembled monolayer removal liquid is located within a first Hansen sphere of the forming material of the self-assembled monolayer, which is defined on the Hansen solubility parameter space by a center value (d di, d pi, d hi) [MPa 1 / 2 ] and a sphere radius R1 [MPa 1 / 2 ], and located within a 2nd Hansen sphere defined by a center value (d2, p2, h2) [MPa 1 / 2 ] and a sphere radius R2 [MPa 1 / 2 ] of the self-assembled monolayer in the Hansen solubility parameter space, the material for forming the self-assembled monolayer is octadecylphosphonic acid, the self-assembled monolayer contains a monolayer of the octadecylphosphonic acid, The first Hansen sphere is defined in the Hansen solubility parameter space by the center values (d di, d pi, d hi) = (16.9 ± 0.2, 5.4 ± 0.5, 11.7 ± 0.3) [MPa 1 / 2 ], and the sphere radius R1= 3.7 [MPa 1 / 2 ], The 2nd Hansen sphere is defined in the Hansen solubility parameter space by the center values (d2, dP2, dh2) = (16.4 ± 0.7, 6.1 ± 1.2, 0.0 ± 2.0) [MPa 1 / 2 ] and the sphere radius R2= 10.2 [MPa 1 / 2 ].

4. The substrate processing method according to claim 3, wherein the preparation step is a step of: preparing the self-assembled monolayer removal liquid in such a manner that the Hansen solubility parameter of the self-assembled monolayer removal liquid becomes a value located at the center of a circle formed by the intersection of the first Hansen sphere and the second Hansen sphere, or a value located at a tangent point of the first Hansen sphere and the second Hansen sphere.

5. The substrate processing method according to claim 3, wherein the self-assembled monolayer removal liquid is at least one organic solvent selected from the group consisting of 1-butanol, 2-butanol, 1-pentanol, tetrahydrofuran, and benzyl alcohol.

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