JP7629083B2 - Drug solution, drug solution container - Google Patents

Description

The present invention relates to a medicinal liquid and a medicinal liquid container.

During the manufacture of semiconductor devices by a wiring formation process including photolithography, chemical solutions containing water and/or an organic solvent are used as a pre-wet solution, a resist solution (a composition for forming a resist film), a developer, a rinse solution, a stripping solution, a chemical mechanical polishing (CMP) slurry, and a cleaning solution after CMP, or as a dilution solution thereof.
In recent years, advances in photolithography technology have led to progress in miniaturization of patterns. As a method for miniaturizing patterns, attempts have been made to form patterns using ultraviolet light, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet) and the like as exposure light sources.
As the patterns to be formed become finer, the above-mentioned chemicals used in this process are required to have a higher defect suppression capability.

As a chemical used in conventional pattern formation, Patent Document 1 discloses "a method for producing an organic processing liquid for patterning a chemically amplified resist film that can reduce particle generation in pattern formation technology (paragraph [0010])."

JP 2015-084122 A

Meanwhile, in recent years, there has been a demand for chemical solutions that are less likely to cause metal residue defects on a silicon substrate or a silicon substrate with a silicon oxide film (a silicon substrate whose surface is covered with a silicon oxide film) when the chemical solutions are brought into contact with the silicon substrate or the silicon substrate with a silicon oxide film.
An object of the present invention is to provide a chemical solution that is less likely to cause metal residue defects when brought into contact with a silicon substrate or a silicon substrate with a silicon oxide film.
Another object of the present invention is to provide a drug solution container.

As a result of intensive research into solving the above problems, the inventors have discovered that the above problems can be solved by the following configuration.

(1) A chemical solution containing an organic solvent and a metal component,
The metal component contains titanium oxide particles and titanium ions,
A chemical solution having a mass ratio of a content of titanium oxide particles to a content of titanium ions of 10 ⁰ to 10 ¹² .
(2) The chemical solution according to (1), wherein the content of titanium ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution.
(3) The chemical solution according to (1) or (2), in which the content of titanium oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of titanium components in the metal components.
(4) The chemical solution according to any one of (1) to (3), in which the proportion of particles having a particle size of 0.5 to 17 nm among the titanium oxide particles is 60 mass % or more and less than 98 mass %.
(5) The metal component contains iron ions,
The chemical solution according to any one of (1) to (4), wherein the content of iron ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution.
(6) The metal component contains iron oxide particles,
The chemical solution according to any one of (1) to (5), wherein the content of the iron oxide particles is 5 mass% or more and less than 99 mass% of the iron component content in the metal component.
(7) The metal component contains iron oxide particles,
The chemical solution according to any one of (1) to (6), wherein the proportion of particles having a particle size of 0.5 to 17 nm among the iron oxide particles is 60 mass % or more and less than 98 mass %.
(8) The metal component contains iron oxide particles and iron ions,
The chemical solution according to any one of (1) to (7), wherein the mass ratio of the content of the iron oxide particles to the content of the iron ions is 10 ⁰ to 10 ¹² .
(9) The metal component contains aluminum ions,
The chemical solution according to any one of (1) to (8), wherein the content of aluminum ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution.
(10) The metal component contains aluminum oxide particles,
The chemical solution according to any one of (1) to (9), wherein the content of the aluminum oxide particles is 5 mass% or more and less than 99 mass% with respect to the content of the aluminum component in the metal component.
(11) The metal component contains aluminum oxide particles,
The chemical solution according to any one of (1) to (10), wherein the proportion of aluminum oxide particles having a particle size of 0.5 to 17 nm is 60 mass % or more and less than 98 mass %.
(12) The metal component contains aluminum oxide particles and aluminum ions,
The chemical solution according to any one of (1) to (11), wherein the mass ratio of the content of aluminum oxide particles to the content of aluminum ions is 10 ⁰ to 10 ¹² .
(13) The metal component contains copper oxide particles,
The chemical solution according to any one of (1) to (12), wherein the content of the copper oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the copper component in the metal component.
(14) The metal component contains copper oxide particles,
The chemical solution according to any one of (1) to (13), wherein the proportion of copper oxide particles having a particle size of 0.5 to 17 nm is 60 mass% or more and less than 98 mass%.
(15) The metal component contains copper oxide particles and copper ions,
The chemical solution according to any one of (1) to (14), wherein the mass ratio of the content of copper oxide particles to the content of copper ions is 10 ⁰ to 10 ¹² .
(16) Further containing organic impurities,
The chemical solution according to any one of (1) to (15), wherein the content of organic impurities is 1,000 to 100,000 ppt by mass relative to the total mass of the chemical solution.
(17) The chemical solution according to any one of (1) to (16), wherein the water content relative to the total mass of the chemical solution is 500 ppb by mass or less.
(18) The chemical solution according to any one of (1) to (17), wherein the organic solvent comprises one or more selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclohexanone, ethyl lactate, propylene carbonate, isopropanol, 4-methyl-2-pentanol, butyl acetate, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl methoxypropionate, cyclopentanone, γ-butyrolactone, diisoamyl ether, isoamyl acetate, dimethyl sulfoxide, N-methylpyrrolidone, diethylene glycol, ethylene glycol, dipropylene glycol, propylene glycol, ethylene carbonate, sulfolane, cycloheptanone, 2-heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, and undecane.
(19) A drug solution container comprising a container and the drug solution according to any one of (1) to (18) contained in the container.

According to the present invention, it is possible to provide a chemical solution which is less likely to cause metal residue defects when brought into contact with a silicon substrate or a silicon substrate with a silicon oxide film.
Further, according to the present invention, a drug solution container can be provided.

The present invention will be described in detail below.
The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.
In this specification, a numerical range expressed using "to" means a range that includes the numerical values before and after "to" as the lower and upper limits.
In addition, in the present invention, "ppm" means "parts-per-million ( ^10-6 )", "ppb" means "parts-per-billion ( ^10-9 )", "ppt" means "parts-per-trillion ( ^10-12 )", and "ppq" means "parts-per-quadrillion ( ^10-15 )".
In addition, in the description of groups (atomic groups) in the present invention, descriptions that do not indicate whether they are substituted or unsubstituted include groups that do not have a substituent as well as groups that contain a substituent, within the scope of the present invention. For example, a "hydrocarbon group" includes not only a hydrocarbon group that does not have a substituent (unsubstituted hydrocarbon group), but also a hydrocarbon group that contains a substituent (substituted hydrocarbon group). This point is the same for each compound.
In the present invention, "radiation" refers to, for example, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, or electron beams. In the present invention, light refers to actinic light or radiation. Unless otherwise specified, "exposure" in the present invention includes not only exposure to far ultraviolet light, X-rays, EUV, or the like, but also drawing with particle beams such as electron beams or ion beams.

Although the mechanism by which the drug solution of the present invention solves the above problems is not entirely clear, the present inventors speculate on the mechanism as follows: Note that the following mechanism is merely speculation, and even if the effect of the present invention is obtained through a different mechanism, it is still within the scope of the present invention.
The present inventors have found that when the chemical solution contains titanium oxide particles and titanium ions, the likelihood of metal residue defects (residues derived from metal components) occurring on a silicon substrate or a silicon substrate with a silicon oxide film (hereinafter, these are also collectively referred to as "specific substrates") varies depending on the mass ratio (mass of titanium oxide particles/mass of oxide ions). More specifically, when the mass ratio is too large, in other words, when the proportion of titanium oxide particles is too high, it is considered that metal residue defects derived from titanium oxide particles are likely to increase on the specific substrate. On the other hand, when the mass ratio is too small, in other words, when the proportion of titanium ions is too high, it is considered that an oxidation-reduction reaction between titanium ions and other metal ions that are less noble than titanium ions is likely to proceed, and particles of other metals (e.g., oxide particles of other metals) increase, which is likely to increase metal residue defects on the specific substrate.

The chemical solution of the present invention is a chemical solution containing an organic solvent and a metal component, the metal component containing titanium oxide particles and titanium ions, and the mass ratio of the titanium oxide particle content to the titanium ion content is ^10.sup.0 to ^10.sup.12 .
The components contained in the drug solution of the present invention will be described in detail below.

<Organic Solvent>
The chemical solution of the present invention (hereinafter, also simply referred to as "chemical solution") contains an organic solvent.
In this specification, the organic solvent refers to a liquid organic compound contained in an amount exceeding 10,000 ppm by mass per component relative to the total mass of the chemical solution. In other words, in this specification, a liquid organic compound contained in an amount exceeding 10,000 ppm by mass relative to the total mass of the chemical solution corresponds to an organic solvent.
In addition, in this specification, the term "liquid" means that the material is liquid at 25° C. and atmospheric pressure.

The content of the organic solvent in the chemical solution is not particularly limited, but is preferably 98.0% by mass or more, more preferably more than 99.0% by mass, still more preferably 99.90% by mass or more, and particularly preferably more than 99.95% by mass, based on the total mass of the chemical solution. The upper limit is less than 100% by mass.
The organic solvent may be used alone or in combination of two or more. When two or more organic solvents are used, the total content is preferably within the above range.

The type of organic solvent is not particularly limited, and known organic solvents can be used. Examples of organic solvents include alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds which may have a ring (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, alkyl pyruvates, dialkyl sulfoxides, cyclic sulfones, dialkyl ethers, monohydric alcohols, glycols, alkyl acetates, and N-alkylpyrrolidones.

The organic solvent is preferably at least one selected from the group consisting of, for example, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone (CHN), ethyl lactate (EL), propylene carbonate (PC), isopropanol (IPA), 4-methyl-2-pentanol (MIBC), butyl acetate (nBA), propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl methoxypropionate, cyclopentanone, γ-butyrolactone, diisoamyl ether, isoamyl acetate, dimethyl sulfoxide, N-methylpyrrolidone, diethylene glycol, ethylene glycol, dipropylene glycol, propylene glycol, ethylene carbonate, sulfolane, cycloheptanone, 2-heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, and undecane.
Examples of using two or more organic solvents include a combined use of PGMEA and PGME, and a combined use of PGMEA and PC.
The type and content of the organic solvent in the chemical solution can be measured using a gas chromatograph mass spectrometer.

<Metal Components>
The chemical solution contains a metal component.
The metal component is composed of metal-containing particles and metal ions, and for example, the content of the metal component refers to the total content of the metal-containing particles and metal ions.
The metal-containing particles may be any particles containing metal atoms, and examples thereof include metal oxide particles, metal nitride particles, and metal particles. Note that the metal particles refer to particles made of metal.

The metal components contained in the chemical solution include titanium oxide particles and titanium ions.
The mass ratio of the titanium oxide particle content to the titanium ion content is 10 ⁰ to 10 ¹² , and from the viewpoint of less likely occurrence of metal residue defects or composite residue defects described below on a silicon substrate or a silicon oxide film, the mass ratio is preferably 10 ¹ to 10 ¹⁰ , more preferably 10 ² to 10 ¹⁰ , even more preferably 10 ³ to 10 ⁸ , and particularly preferably 10 ³ to 10 ⁷ .

The titanium ion content is not particularly limited, and is often 0.01 to 150 ppt by mass. In particular, the titanium ion content is preferably 0.10 to 100 ppt by mass, and more preferably 1.0 to 70 ppt by mass, relative to the total mass of the chemical solution, in that metal residue defects or compound residue defects described below are less likely to occur on the silicon substrate or silicon oxide film.

The content of the titanium oxide particles is not particularly limited, and is often 1 mass % or more and less than 100 mass % based on the content of the titanium component in the metal component. In particular, the content of the titanium oxide particles is preferably 5 mass % or more and less than 99 mass %, more preferably 30 to 90 mass %, based on the content of the titanium component in the metal component, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.
The titanium component is a component that contains titanium atoms, and examples of the titanium component include titanium-containing particles and titanium ions. For example, the content of the titanium component refers to the total content of the titanium-containing particles and titanium ions.
The titanium-containing particles may be any particles containing titanium atoms, and examples thereof include titanium oxide particles, titanium nitride particles, and titanium particles. Note that the titanium particles refer to particles made of metallic titanium.

The proportion of titanium oxide particles having a particle size of 0.5 to 17 nm is not particularly limited, and is often 40% by mass or more and less than 100% by mass. In particular, the proportion of titanium oxide particles having a particle size of 0.5 to 17 nm is preferably 60% by mass or more and less than 98% by mass, and more preferably 60 to 95% by mass, in order to prevent metal residue defects or composite residue defects described below from occurring on the silicon substrate or silicon oxide film.

The metal component contained in the chemical solution may contain iron ions.
The content of iron ions is not particularly limited, and is often 0.01 to 200 ppt by mass relative to the total mass of the chemical solution. In particular, the content of iron ions is preferably 0.1 to 100 ppt by mass, and more preferably 1.0 to 90 ppt by mass, relative to the total mass of the chemical solution, in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film.

The metal component contained in the chemical solution may contain iron oxide particles.
The content of the iron oxide particles is not particularly limited, and is often 1 mass % or more and less than 100 mass % based on the content of the iron component in the metal component. In particular, the content of the iron oxide particles is preferably 5 mass % or more and less than 99 mass %, more preferably 10 to 95 mass %, based on the content of the iron component in the metal component, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.
The iron component is a component that contains iron atoms, and examples of such components include iron-containing particles and iron ions. For example, the content of the iron component refers to the total content of the iron-containing particles and iron ions.
The iron-containing particles may be any particles containing iron atoms, and examples of such particles include iron oxide particles, iron nitride particles, and iron particles. Note that the iron particles refer to particles made of metallic iron.

The proportion of particles with a particle size of 0.5 to 17 nm among the iron oxide particles is not particularly limited, and is often 40% by mass or more and less than 100% by mass. In particular, the proportion of particles with a particle size of 0.5 to 17 nm among the iron oxide particles is preferably 60% by mass or more and less than 98% by mass, and more preferably 60 to 95% by mass, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.

The mass ratio of the content of iron oxide particles to the content of iron ions in the chemical solution is not particularly limited, and is often 10 ⁻² to 10 ^14. Among these, the mass ratio is preferably 10 ⁰ to 10 12, more preferably 10 2 to 10 ¹⁰ , even more preferably 10 ³ to 10 ^{8, and particularly preferably 10 3 to 10 7 , in that} metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or ^silicon oxide film.

The metal component contained in the chemical solution may contain aluminum ions.
The content of aluminum ions is not particularly limited, and is often 0.01 to 200 ppt by mass relative to the total mass of the chemical solution. In particular, the content of aluminum ions is preferably 0.1 to 100 ppt by mass, more preferably 1.0 to 90 ppt by mass, relative to the total mass of the chemical solution, in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film.

The metal component contained in the chemical solution may contain aluminum oxide particles.
The content of the aluminum oxide particles is not particularly limited, and is often 1 mass % or more and less than 100 mass % based on the content of the aluminum component in the metal component. In particular, the content of the aluminum oxide particles is preferably 5 mass % or more and less than 99 mass %, more preferably 10 to 95 mass %, based on the content of the aluminum component in the metal component, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.
The aluminum component is a component that contains aluminum atoms, and examples of such components include aluminum-containing particles and aluminum ions. For example, the content of the aluminum component refers to the total content of the aluminum-containing particles and aluminum ions.
The aluminum-containing particles may be any particles containing aluminum atoms, and examples thereof include aluminum oxide particles, aluminum nitride particles, and aluminum particles. Note that the aluminum particles refer to particles made of metallic aluminum.

The proportion of aluminum oxide particles having a particle size of 0.5 to 17 nm is not particularly limited, and is often 40% by mass or more and less than 100% by mass. In particular, the proportion of aluminum oxide particles having a particle size of 0.5 to 17 nm is preferably 60% by mass or more and less than 98% by mass, and more preferably 60 to 95% by mass, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.

The mass ratio of the content of aluminum oxide particles to the content of aluminum ions in the chemical solution is not particularly limited, and is often 10 ⁻² to 10 ^14. Among these, the mass ratio is preferably 10 ⁰ to 10 12, more preferably 10 ² to 10 ¹⁰ , still more preferably 10 ³ to 10 ^{8, and particularly preferably 10 3 to 10 7 , in} that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or ^silicon oxide film.

The metal components contained in the chemical solution may contain metal atom components other than those mentioned above.
Examples of other metal atoms include Na (sodium), K (potassium), Ca (calcium), Cu (copper), Mg (magnesium), Mn (manganese), Li (lithium), Cr (chromium), Ni (nickel), and Zr (zirconium).

The metal component contained in the chemical solution may contain copper oxide particles.
The content of the copper oxide particles is not particularly limited, and is often 1 mass % or more and less than 100 mass % based on the content of the copper component in the metal component. In particular, the content of the copper oxide particles is preferably 5 mass % or more and less than 99 mass %, more preferably 10 to 95 mass %, based on the content of the copper component in the metal component, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.
The copper component is a component that contains copper atoms, and examples thereof include copper-containing particles and copper ions. For example, the content of the copper component refers to the total content of the copper-containing particles and copper ions.
The copper-containing particles may be any particles containing copper atoms, and examples thereof include copper oxide particles, copper nitride particles, and copper particles. Note that the copper particles refer to particles made of metallic copper.

The proportion of copper oxide particles having a particle size of 0.5 to 17 nm is not particularly limited, and is often 40% by mass or more and less than 100% by mass. In particular, the proportion of copper oxide particles having a particle size of 0.5 to 17 nm is preferably 60% by mass or more and less than 98% by mass, and more preferably 60 to 95% by mass, in order to prevent metal residue defects or composite residue defects described later from occurring on the silicon substrate or silicon oxide film.

The mass ratio of the content of copper oxide particles to the content of copper ions in the chemical solution is not particularly limited, and is often 10 ⁻² to 10 ^14. Among these, the mass ratio is preferably 10 ⁰ to 10 12, more preferably 10 ² to 10 ¹⁰ , still more preferably 10 ³ to 10 ^{8, and particularly preferably 10 3 to 10 7 , in} that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or ^silicon oxide film.

The metal components may be metal components that are inevitably contained in each component (raw material) contained in the chemical solution, metal components that are inevitably contained during the production, storage, and/or transportation of the treatment solution, or metal components that are intentionally added.

The amount of metal components contained is not particularly limited, but is preferably 10 to 500,000 mass ppt relative to the total mass of the chemical solution, since this makes it less likely that metal residue defects or composite residue defects, which will be described later, will occur on the silicon substrate or silicon oxide film.

The types and contents of metal ions and metal-containing particles in the chemical solution can be measured by SP-ICP-MS (Single Nano Particle Inductively Coupled Plasma Mass Spectrometry).
Here, the SP-ICP-MS method uses the same equipment as the normal ICP-MS method (inductively coupled plasma mass spectrometry), and differs only in the data analysis, which can be performed using commercially available software.
In the ICP-MS method, the content of the metal component to be measured is measured regardless of the form in which it exists. Therefore, the total mass of the metal-containing particles and metal ions to be measured is quantified as the content of the metal component.

On the other hand, the SP-ICP-MS method can measure the content of metal-containing particles, and therefore the content of metal ions in a sample can be calculated by subtracting the content of metal-containing particles from the content of metal components in the sample.
An example of an apparatus for the SP-ICP-MS method is Agilent 8800 triple quadrupole ICP-MS (inductively coupled plasma mass spectrometry, for semiconductor analysis, option #200) manufactured by Agilent Technologies, which can be measured by the method described in the Examples. As an apparatus other than the above, PerkinElmer's NexION350S and Agilent Technologies' Agilent 8900 can also be used.

In addition, since metal-containing particles of 10 nm or less cannot be measured by SP-ICP-MS, the method described in paragraphs 0015 to 0067 of JP 2009-188333 A (hereinafter also referred to as the "specifying method") is used.
Here, the number of 0.5-10 nm particles remaining on the substrate is counted using a specific method, and the conversion value from SNP-ICP-MS for 20 nm particles is used for that count. Since the conversion value differs for each metal, this conversion is performed for each metal.
The specific method of conversion is as follows:
For example, if the number of 20 nm titanium oxide particles in the chemical solution is 10 by SNP-ICP-MS, and the number of 20 nm titanium oxide particles remaining on the substrate calculated by the specified method is 1, the conversion value is 10. In other words, if the number of 1 nm titanium oxide particles confirmed by the specified method is 100, the conversion value is multiplied by 10 to calculate that there are 1,000 particles (100 particles x 10) in the chemical solution. The number of particles of 10 nm or less in the present invention is estimated by this conversion method, regardless of the metal.

<Organic impurities>
The chemical solution may contain organic impurities.
The content of organic impurities in the chemical solution is not particularly limited, but is preferably 1,000 to 100,000 ppt by mass relative to the total mass of the chemical solution, in that stain-like residue defects described below are less likely to occur on the silicon substrate.
The organic impurities refer to organic compounds that are different from organic solvents and are contained in an amount of 10,000 ppm by mass or less relative to the total mass of the organic solvent. In other words, in this specification, organic compounds that are contained in an amount of 10,000 ppm by mass or less relative to the total mass of the organic solvent are considered to be organic impurities and not organic solvents.
Organic impurities are often mixed into or added to a chemical solution during the process of purifying a material to be purified to obtain a chemical solution. Examples of such organic impurities include plasticizers, antioxidants, and compounds derived from these (typically decomposition products).

<Water>
The chemical solution may contain water, which is not included in the organic impurities.
The water is not particularly limited, and for example, distilled water, ion-exchanged water, pure water, etc. can be used.
Water may be added to the chemical solution, or may be unintentionally mixed into the chemical solution during the manufacturing process of the chemical solution. Examples of unintentional mixing during the manufacturing process of the chemical solution include, but are not limited to, when water is contained in a raw material (e.g., an organic solvent) used in the manufacturing of the chemical solution, and when water is mixed during the manufacturing process of the chemical solution (e.g., contamination).

The water content in the chemical solution is not particularly limited, but is preferably 2.0% by mass or less, and more preferably 500 ppb by mass or less, based on the total mass of the chemical solution. The lower limit is not particularly limited, but can be 0% by mass. The water content in the chemical solution refers to the water content measured using an apparatus that uses the Karl Fischer moisture content measurement method as the measurement principle.

<Use of chemicals>
The chemical solution of the present invention is preferably used in the manufacture of semiconductor devices, and in particular, it is preferable to manufacture semiconductor chips using the chemical solution of the present invention.
Specifically, in the manufacturing process of semiconductor devices including a lithography process, an etching process, an ion implantation process, a peeling process, and the like, the liquid is used to treat organic matter after the completion of each process or before moving to the next process, and specifically, is suitably used as a pre-wet liquid, a developing liquid, a rinsing liquid, a polishing liquid, and the like.
In addition, the chemical liquid may be used as a diluting liquid (in other words, a solvent) for the resin contained in the composition for forming a resist film.

Furthermore, the above-mentioned chemical solution can be used for purposes other than the manufacture of semiconductor devices, and can also be used as a developer and rinse solution for polyimide, resist for sensors, resist for lenses, and the like.
The chemical solution can also be used as a solvent for medical or cleaning purposes, for example, for cleaning pipes, containers, and substrates (e.g., wafers, glass, etc.).
As the above-mentioned cleaning application, it is also preferable to use it as a cleaning liquid (pipe cleaning liquid, container cleaning liquid, etc.) for cleaning pipes, containers, etc. that come into contact with liquids such as the above-mentioned pre-wet liquid.

Among these, the chemical liquid is preferably used for the pre-wet liquid, developer, rinse liquid, polishing liquid, and resist film forming composition. In particular, when applied to the pre-wet liquid, developer, and rinse liquid, it exerts a more excellent effect. In particular, when applied to the pre-wet liquid, developer, and rinse liquid when the exposure light source is EUV, it exerts a more excellent effect. It also exerts a more excellent effect when applied to the pipe cleaning liquid used for the pipes used to transport these liquids.

<Method of manufacturing chemical solution>
The method for producing the above-mentioned chemical solution is not particularly limited, and any known production method can be used. Among them, the method for producing the chemical solution preferably includes a filtration step of filtering the product to be purified containing an organic solvent using a filter to obtain the chemical solution, in order to obtain a chemical solution that exhibits a more excellent effect of the present invention.

The product to be purified used in the filtration process may be procured by purchase or may be obtained by reacting raw materials. It is preferable that the product to be purified has a low impurity content. Examples of commercially available products of such products include those called "high purity grade products."

The method for obtaining a product to be purified (typically a product to be purified containing an organic solvent) by reacting raw materials is not particularly limited, and any known method can be used. For example, there is a method for obtaining an organic solvent by reacting one or more raw materials in the presence of a catalyst.
More specifically, for example, there can be mentioned a method of reacting acetic acid with n-butanol in the presence of sulfuric acid to obtain butyl acetate; a method of reacting ethylene, oxygen, and water in the presence of Al(C ₂ H ₅ ) ₃ to obtain 1-hexanol; a method of reacting cis-4-methyl-2-pentene in the presence of Ipc2BH (Diisopinocampheylborane) to obtain 4-methyl-2-pentanol; a method of reacting propylene oxide, methanol, and acetic acid in the presence of sulfuric acid to obtain PGMEA (propylene glycol 1-monomethyl ether 2-acetate); a method of reacting acetone and hydrogen in the presence of copper oxide-zinc oxide-aluminum oxide to obtain IPA (isopropyl alcohol); a method of reacting lactic acid and ethanol to obtain ethyl lactate; and the like.

(Filtration process)
The method for producing a drug solution of the present invention preferably includes a filtration step of filtering the target substance using a filter to obtain a drug solution. The method for filtering the target substance using a filter is not particularly limited, but it is preferable to pass the target substance through a filter unit having a housing and a filter cartridge housed in the housing with or without pressure.

- Filter pore size The filter pore size is not particularly limited, and a filter with a pore size that is usually used for filtering the product to be purified can be used. Among them, the filter pore size is preferably 200 nm or less, more preferably 20 nm or less, even more preferably 10 nm or less, and particularly preferably 5 nm or less, in terms of ease of controlling the number of particles (metal particles, etc.) contained in the chemical solution to a desired range. The lower limit is not particularly limited, but generally 1 nm or more is preferred from the viewpoint of productivity.
In this specification, the pore size of the filter means the pore size determined by the bubble point of isopropanol (IPA).

It is preferable that the pore size of the filter is 5.0 nm or less, since it is easier to control the number of particles contained in the drug solution. Hereinafter, a filter having a pore size of 5.0 nm or less is also referred to as a "micropore filter".
The micropore filter may be used alone or together with a filter having another pore size. In particular, it is preferable to use a filter having a larger pore size from the viewpoint of superior productivity. In other words, when two or more filters are used, it is preferable that the pore size of at least one filter is 5.0 nm or less. In this case, if the product to be purified, which has been previously filtered through a filter having a larger pore size, is passed through the micropore filter, clogging of the micropore filter can be prevented.
That is, when one filter is used, the pore size of the filter is preferably 5.0 nm or less, and when two or more filters are used, the pore size of the filter having the smallest pore size is preferably 5.0 nm or less.

The form in which two or more filters with different pore sizes are used in sequence is not particularly limited, but includes a method of arranging the filter units already described in sequence along the pipeline through which the product to be purified is transported. In this case, if an attempt is made to keep the flow rate per unit time of the product to be purified constant throughout the entire pipeline, a filter with a smaller pore size may be subjected to greater pressure than a filter with a larger pore size. In this case, it is preferable to arrange a pressure adjustment valve and a damper between the filters to keep the pressure on the filter with a smaller pore size constant, or to arrange filter units containing the same filters in parallel along the pipeline to increase the filtration area. In this way, the number of particles in the chemical solution can be controlled more stably.

Filter Material The filter material is not particularly limited, and known materials can be used as filter materials. Specifically, in the case of resins, examples of the filter material include polyamides such as nylon (e.g., 6-nylon and 6,6-nylon), polyolefins such as polyethylene and polypropylene, polystyrene, polyimide, polyamideimide, poly(meth)acrylate, polyfluorocarbons such as polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride, polyvinyl alcohol, polyester, cellulose, and cellulose acetate.
Among these, at least one selected from the group consisting of nylon (among which 6,6-nylon is preferred), polyolefin (among which polyethylene is preferred), poly(meth)acrylate, and polyfluorocarbon (among which polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA) are preferred) is preferred, in that it has better solvent resistance and the resulting chemical solution has better defect suppression performance. These polymers can be used alone or in combination of two or more.
In addition to resin, materials such as diatomaceous earth and glass may also be used.
Alternatively, a polymer (such as nylon graft UPE) in which polyamide (for example, nylon such as nylon-6 or nylon-6,6) is graft-copolymerized with polyolefin (such as UPE (ultra-high molecular weight polyethylene) described below) may be used as the material for the filter.

The filter may also be a surface-treated filter. There are no particular limitations on the method of surface treatment, and any known method can be used. Examples of surface treatment methods include chemical modification treatment, plasma treatment, hydrophobic treatment, coating, gas treatment, and sintering.

Plasma treatment is preferred because it makes the filter surface hydrophilic. There are no particular limitations on the water contact angle on the surface of a filter that has been hydrophilized by plasma treatment, but the static contact angle at 25°C measured with a contact angle meter is preferably 60° or less, more preferably 50° or less, and even more preferably 30° or less.

As the chemical modification treatment, a method of introducing an ion exchange group into the filter is preferable.
That is, the filter is preferably a filter having an ion exchange group.
Examples of the ion exchange group include a cation exchange group and an anion exchange group, examples of the cation exchange group include a sulfonic acid group, a carboxyl group, and a phosphate group, and examples of the anion exchange group include a quaternary ammonium group, etc. The method for introducing the ion exchange group into the filter is not particularly limited, but examples of the method include a method in which a compound containing an ion exchange group and a polymerizable group is reacted with the filter to typically perform grafting.

There are no particular limitations on the method for introducing ion exchange groups, but the filter is irradiated with ionizing radiation (alpha rays, beta rays, gamma rays, X-rays, electron beams, etc.) to generate active moieties (radicals). After this irradiation, the filter is immersed in a monomer-containing solution to graft polymerize the monomer onto the filter. As a result, the polymer obtained by polymerization of the monomer is grafted onto the filter. The generated polymer is contacted with a compound containing an anion exchange group or a cation exchange group to introduce ion exchange groups into the polymer.

The filter may also be constructed by combining a woven or nonwoven fabric in which ion exchange groups have been formed by radiation graft polymerization with a conventional glass wool, woven or nonwoven filter material.

By using a filter having an ion exchange group, the content of metal-containing particles and metal ions in the chemical solution can be easily controlled to a desired range. The material constituting the filter having an ion exchange group is not particularly limited, but examples thereof include polyfluorocarbons and materials in which ion exchange groups are introduced into polyolefins, and materials in which ion exchange groups are introduced into polyfluorocarbons are more preferable.
The pore size of the filter having an ion exchange group is not particularly limited, but is preferably 1 to 30 nm, and more preferably 5 to 20 nm. The filter having an ion exchange group may also serve as the filter having the smallest pore size as described above, or may be used separately from the filter having the smallest pore size. Among these, in terms of obtaining a chemical solution that exhibits a more excellent effect of the present invention, the filtration step preferably uses a filter having an ion exchange group and a filter having a smallest pore size that does not have an ion exchange group.
The material of the filter having the minimum pore size already described is not particularly limited, but from the viewpoint of solvent resistance and the like, generally, at least one selected from the group consisting of polyfluorocarbons and polyolefins is preferred, and polyolefins are more preferred.

Therefore, the filters used in the filtration process may be made of two or more different materials, for example, two or more selected from the group consisting of filters made of polyolefins, polyfluorocarbons, polyamides, and materials into which ion exchange groups have been introduced.

-Pore structure of the filter The pore structure of the filter is not particularly limited and may be appropriately selected depending on the components in the product to be purified. In this specification, the pore structure of the filter means the pore size distribution, the positional distribution of the pores in the filter, the shape of the pores, etc., and can typically be controlled by the manufacturing method of the filter.
For example, a porous membrane can be obtained by sintering powder of resin or the like, and a fibrous membrane can be obtained by forming the membrane by methods such as electrospinning, electroblowing, and meltblowing, each of which has a different pore structure.

"Porous membrane" means a membrane that retains components of the product to be purified, such as gels, particles, colloids, cells, and poly-oligomers, but allows components substantially smaller than the pores to pass through the pores. Retention of components of the product by a porous membrane may depend on operating conditions, such as face velocity, use of surfactants, pH, and combinations thereof, and may depend on the pore size, structure of the porous membrane, and the size and structure of the particles to be removed (e.g., hard particles or gels).

When the product to be purified contains negatively charged particles, polyamide filters act as non-sieving membranes to remove such particles. Exemplary non-sieving membranes include, but are not limited to, nylon membranes such as nylon-6 membranes and nylon-6,6 membranes.
It is noted that, as used herein, "non-sieving" retention mechanisms refer to retention that occurs due to mechanisms such as obstruction, diffusion, and adsorption that are not related to the pressure drop or pore size of the filter.

Non-sieving retention includes retention mechanisms such as obstruction, diffusion, and adsorption that remove target particles in the product, regardless of the pressure drop across the filter or the pore size of the filter. Particle adsorption to the filter surface can be mediated, for example, by intermolecular van der Waals and electrostatic forces. Obstruction effects occur when particles moving through a non-sieving membrane layer with a tortuous path cannot be redirected quickly enough to avoid contact with the non-sieving membrane. Particle transport by diffusion results primarily from random or Brownian motion of small particles, which creates a certain probability of the particle colliding with the filter media. Non-sieving retention mechanisms can be active when there are no repulsive forces between the particle and the filter.

UPE (ultra-high molecular weight polyethylene) filters are typically sieving membranes, which refers to membranes that capture particles primarily through a sieving retention mechanism or that are optimized for capturing particles through a sieving retention mechanism.
Typical examples of sieving membranes include, but are not limited to, polytetrafluoroethylene (PTFE) membranes and UPE membranes.
The "sieve retention mechanism" refers to the retention of particles that are larger than the pore size of the porous membrane. Sieve retention is improved by forming a filter cake (an agglomeration of particles to be removed on the membrane surface). The filter cake effectively performs the function of a secondary filter.

The material of the fiber membrane is not particularly limited as long as it is a polymer capable of forming a fiber membrane. Examples of the polymer include polyamides. Examples of the polyamide include nylon 6 and nylon 6,6. The polymer forming the fiber membrane may be poly(ethersulfone). When the fiber membrane is on the primary side of the porous membrane, it is preferable that the surface energy of the fiber membrane is higher than that of the polymer that is the material of the porous membrane on the secondary side. An example of such a combination is when the fiber membrane is made of nylon and the porous membrane is made of polyethylene (UPE).

The method for producing the fiber membrane is not particularly limited, and any known method can be used. Examples of methods for producing the fiber membrane include electrospinning, electroblowing, and meltblowing.

The pore structure of the porous membrane (e.g., porous membranes containing UPE, PTFE, etc.) is not particularly limited, but examples of the pore shape include lace-like, string-like, and node-like.
The distribution of the pore sizes in the porous membrane and the distribution of the positions in the membrane are not particularly limited. The size distribution may be smaller and the distribution positions in the membrane may be symmetric. The size distribution may be larger and the distribution positions in the membrane may be asymmetric (the above membrane is also called "asymmetric porous membrane"). In an asymmetric porous membrane, the size of the pores changes in the membrane, and typically the pore size increases from one surface of the membrane to the other surface of the membrane. In this case, the surface on the side where there are more pores with large pore sizes is called the "open side", and the surface on the side where there are more pores with small pore sizes is also called the "tight side".
Asymmetric porous membranes include, for example, membranes in which the pore size is smallest at some point within the thickness of the membrane (also called "hourglass shaped").

By using an asymmetric porous membrane with larger pore size on the primary side, in other words the primary side being the open side, a pre-filtration effect can be created.

The porous membrane may include a thermoplastic polymer such as PESU (polyethersulfone), PFA (perfluoroalkoxyalkane, a copolymer of tetrafluoroethylene and perfluoroalkoxyalkane), polyamide, and polyolefin, or may include polytetrafluoroethylene, etc.
Among them, the material of the porous membrane is preferably ultra-high molecular weight polyethylene, which means a thermoplastic polyethylene having an extremely long chain and has a molecular weight of at least one million, typically 2 to 6 million.

The filters used in the filtration process may be two or more types of filters with different pore structures, or a porous membrane filter and a fiber membrane filter may be used in combination. A specific example is a method using a nylon fiber membrane filter and a UPE porous membrane filter.

It is also preferable to thoroughly wash the filter before use.
When an unwashed filter (or a filter that has not been sufficiently washed) is used, impurities contained in the filter are likely to be carried over into the chemical solution.

As described above, the filtration step according to the embodiment of the present invention may be a multistage filtration step in which the material to be purified is passed through two or more types of filters that are different in at least one aspect selected from the group consisting of the filter material, pore size, and pore structure.
The material to be purified may be passed through the same filter multiple times, or through multiple filters of the same type.

In addition, when preparing the medicinal solution of the present invention, it is preferable to use a filter (metal component removal filter) that can selectively remove metal components (especially metal ions) such as "Purasol SN 200 nm".

The material of the liquid-contacting parts of the refining device used in the filtration process (meaning the inner wall surfaces that may come into contact with the product to be refined and the chemical liquid) is not particularly limited, but is preferably made of at least one material selected from the group consisting of non-metallic materials (such as fluororesins) and electrolytically polished metallic materials (such as stainless steel) (hereinafter, these are collectively referred to as "corrosion-resistant materials"). For example, when the liquid-contacting parts of a production tank are made of a corrosion-resistant material, this can mean that the production tank itself is made of a corrosion-resistant material, or that the inner wall surfaces of the production tank are coated with a corrosion-resistant material.

The non-metallic material is not particularly limited, and any known material can be used.
Examples of non-metallic materials include, but are not limited to, at least one selected from the group consisting of polyethylene resin, polypropylene resin, polyethylene-polypropylene resin, and fluorine-based resin (e.g., tetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluorochloroethylene-ethylene copolymer resin, vinylidene fluoride resin, trifluorochloroethylene copolymer resin, and vinyl fluoride resin).

The metal material is not particularly limited, and any known material can be used.
The metallic material may be, for example, a metallic material having a total content of chromium and nickel of more than 25 mass% based on the total mass of the metallic material, and more preferably 30 mass% or more. The upper limit of the total content of chromium and nickel in the metallic material is not particularly limited, but is generally preferably 90 mass% or less.
Examples of metallic materials include stainless steel and nickel-chromium alloys.

The stainless steel is not particularly limited, and known stainless steels can be used. Among them, an alloy containing 8% or more by mass of nickel is preferable, and an austenitic stainless steel containing 8% or more by mass of nickel is more preferable. Examples of austenitic stainless steel include SUS (Steel Use Stainless) 304 (Ni content 8% by mass, Cr content 18% by mass), SUS304L (Ni content 9% by mass, Cr content 18% by mass), SUS316 (Ni content 10% by mass, Cr content 16% by mass), and SUS316L (Ni content 12% by mass, Cr content 16% by mass).

The nickel-chromium alloy is not particularly limited, and any known nickel-chromium alloy can be used. Among them, a nickel-chromium alloy having a nickel content of 40 to 75 mass % and a chromium content of 1 to 30 mass % is preferable.
Examples of nickel-chromium alloys include Hastelloy (trade name, the same applies below), Monel (trade name, the same applies below), and Inconel (trade name, the same applies below). More specifically, examples include Hastelloy C-276 (Ni content: 63 mass%, Cr content: 16 mass%), Hastelloy-C (Ni content: 60 mass%, Cr content: 17 mass%), and Hastelloy C-22 (Ni content: 61 mass%, Cr content: 22 mass%).
Furthermore, the nickel-chromium alloy may further contain boron, silicon, tungsten, molybdenum, copper, cobalt, and the like, in addition to the above-mentioned alloy, as required.

There are no particular limitations on the method for electrolytically polishing the metal material, and any known method can be used. For example, the methods described in paragraphs [0011] to [0014] of JP 2015-227501 A and paragraphs [0036] to [0042] of JP 2008-264929 A can be used.

It is presumed that the chromium content in the surface passive layer of the metal material is higher than the chromium content in the parent phase due to electrolytic polishing, and therefore, it is presumed that metal-containing particles are less likely to flow out into the product to be refined when a refining device with a liquid-contacting part made of an electrolytically polished metal material is used.
The metal material may be buffed. The method of buffing is not particularly limited, and known methods can be used. The size of the abrasive grains used for finishing the buffing is not particularly limited, but #400 or less is preferable because it tends to reduce the unevenness of the surface of the metal material. The buffing is preferably performed before the electrolytic polishing.

(Other processes)
The method for producing the chemical solution may further include a step other than the filtration step, such as a distillation step, a reaction step, and a static electricity removal step.

(Distillation process)
The distillation step is a step of distilling a purification target material containing an organic solvent to obtain a distilled purification target material. The method of distilling the purification target material is not particularly limited, and a known method can be used. A typical example is a method in which a distillation column is disposed on the primary side of a purification apparatus subjected to a filtration step, and the distilled purification target material is introduced into a production tank.
In this case, the liquid-contacting parts of the distillation column are not particularly limited, but are preferably made of the corrosion-resistant materials already explained.

(Reaction step)
The reaction step is a step of reacting the raw materials to produce a product to be purified that contains the organic solvent as a reactant. The method of producing the product to be purified is not particularly limited, and any known method can be used. A typical example is a method in which a reaction tank is disposed on the primary side of a production tank (or a distillation column) of a purification apparatus to be subjected to a filtration step, and the reactant is introduced into the production tank (or the distillation column).
In this case, the liquid-contacting parts of the production tank are not particularly limited, but are preferably made of the corrosion-resistant materials already described.

(Static charge removal process)
The charge removal step is a step of removing static electricity from the material to be purified to reduce the charged potential of the material to be purified.
The method for removing static electricity is not particularly limited, and any known method can be used. For example, the method for removing static electricity includes contacting the product to be purified with a conductive material.
The contact time of the material to be purified with the conductive material is preferably 0.001 to 60 seconds, more preferably 0.001 to 1 second, and even more preferably 0.01 to 0.1 seconds. Examples of the conductive material include stainless steel, gold, platinum, diamond, and glassy carbon.
As a method for contacting the material to be purified with a conductive material, for example, a grounded mesh made of a conductive material is placed inside the pipeline and the material to be purified is passed through the mesh.

It is preferable that the purification of the target substance, as well as the associated processes such as opening containers, cleaning containers and equipment, storing solutions, and analysis, are all carried out in a clean room. The clean room is preferably a clean room with a cleanliness level of class 4 or higher as defined by the international standard ISO14644-1:2015 established by the International Organization for Standardization. Specifically, it is preferable that the clean room meets any of ISO class 1, ISO class 2, ISO class 3, and ISO class 4, more preferably ISO class 1 or ISO class 2, and even more preferably ISO class 1.

There are no particular limitations on the storage temperature of the drug solution, but a storage temperature of 4°C or higher is preferred, as this makes it more difficult for trace amounts of impurities contained in the drug solution to be eluted, resulting in a more excellent effect of the present invention.

<Drug Solution Container>
The drug solution produced by the above purification method may be stored in a container until it is used.
Such a container and the liquid medicine contained therein are collectively referred to as a liquid medicine container. The liquid medicine is taken out of the stored liquid medicine container and used.

The container for storing the above-mentioned chemical solution is preferably one that is highly clean inside and has little elution of impurities for use in semiconductor device manufacturing.
Specific examples of containers that can be used include the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd., but are not limited to these.

As a container, it is also preferable to use a multi-layer bottle whose inner wall has a six-layer structure made of six types of resin, or a multi-layer bottle whose inner wall has a seven-layer structure made of six types of resin, in order to prevent impurities from being mixed in (contaminated) with the liquid medicine. Examples of such containers include the containers described in JP 2015-123351 A.

The liquid-contacting portion of the container may be made of the corrosion-resistant material already described (preferably electrolytically polished stainless steel or fluororesin) or glass. In order to obtain a better effect of the present invention, it is preferable that 90% or more of the area of the liquid-contacting portion is made of the above material, and it is even more preferable that the entire liquid-contacting portion is made of the above material.

The void ratio within the container of the drug solution container is preferably 2 to 80% by volume, more preferably 2 to 50% by volume, and even more preferably 5 to 30% by volume.
The porosity is calculated according to formula (1).
Equation (1): Porosity = {1 - (volume of drug solution in container / volume of container)} x 100
The container volume is synonymous with the internal volume (capacity) of the container.
By setting the porosity within this range, it is possible to ensure storage stability by limiting contamination such as impurities.

The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, processing contents, and processing procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

In addition, when preparing the chemical solutions in the examples and comparative examples, handling of containers, preparation of the chemical solutions, filling, storage, and analytical measurements were all carried out in a clean room that met ISO class 2 or 1 standards.

(Filter)
The following filters were used:
"Purasol SN 200 nm": UPE membrane (material) manufactured by Entegris, pore size 200 nm
"PP 200 nm": polypropylene filter, manufactured by Entegris, pore size 200 nm
・“Purasol SP 200nm”: UPE membrane (material) manufactured by Entegris, pore size 200nm
"Octolex 5 nm": UPE nylon filter graft, Entegris, pore size 5 nm
"IEX 15 nm": ion exchange resin filter, manufactured by Entegris, pore size 15 nm
"IEX 16 nm": ion exchange resin filter, manufactured by Entegris, pore size 16 nm
"IEX 50 nm": ion exchange resin filter, manufactured by Entegris, pore size 50 nm
"IEX 200 nm": ion exchange resin filter, manufactured by Entegris, pore size 200 nm
"PTFE 5 nm": polytetrafluoroethylene filter, manufactured by Entegris, pore size 5 nm
"PTFE 7 nm": polytetrafluoroethylene filter, manufactured by Entegris, pore size 7 nm
"PTFE 10 nm": polytetrafluoroethylene filter, manufactured by Entegris, pore size 10 nm
"PTFE 20 nm": polytetrafluoroethylene filter, manufactured by Entegris, pore size 20 nm
"Nylon 5 nm": Nylon filter, manufactured by Pall, pore size 5 nm
"UPE 1 nm": ultra-high molecular weight polyethylene filter, manufactured by Pall, pore size 1 nm
"UPE 3nm": Ultra-high molecular weight polyethylene filter, manufactured by Pall, pore size 3nm
"UPE 5nm": Ultra-high molecular weight polyethylene filter, manufactured by Pall, pore size 5nm

<Product to be purified>
In order to produce the chemical solutions of the Examples and Comparative Examples, the following organic solvents were used as materials to be purified.
CyHe: Cyclohexanone PGMEA: Propylene glycol monomethyl ether acetate MIBC: 4-methyl-2-pentanol nBA: Butyl acetate EL: Ethyl lactate PC: Propylene carbonate IPA: Isopropanol PGMEE: Propylene glycol monoethyl ether PGMPE: Propylene glycol monopropyl ether CPN: Cyclopentanone In addition, "Raw material 1" to "Raw material 8" in the table indicate that the organic solvents used in each example and comparative example were purchased from the following manufacturers.
"Raw material 1": Honeywell
"Raw material 2": Toyo Gosei "Raw material 3": KH Neochem "Raw material 4": Showa Denko "Raw material 5": KH Neochem "Raw material 6": Sanwa Yuka Kogyo "Raw material 7": CCP
"Raw material 8": BASF

<Container>
The following containers were used to store the drug solutions:
EP-SUS: Container with liquid-contacting parts made of electrolytically polished stainless steel PFA: Container with liquid-contacting parts coated with perfluoroalkoxyalkane The filling rate of the chemical solution in each container was 95% by volume (void ratio was 5% by volume).
The filling rate is calculated by the following formula:
Filling rate = (volume of drug solution in container / volume of container) x 100

Purification Procedure
One of the above-mentioned materials to be purified was selected and subjected to the distillation purification treatment shown in Table 1.
In the "Distillation purification" column in the table, "Yes-1" indicates that reduced pressure distillation was carried out using a distillation tower (theoretical number of plates: 15 plates), "Yes-2" indicates that reduced pressure distillation was carried out twice using a distillation tower (theoretical number of plates: 30 plates), and "Yes-3" indicates that reduced pressure distillation was carried out using a distillation tower (theoretical number of plates: 8 plates).

Next, the distilled and purified product was stored in a storage tank, and the product stored in the storage tank was filtered by passing it through filters 1 to 5 shown in Table 1 in this order, and then stored in the storage tank.
Next, the product to be purified stored in the storage tank was filtered through filters 6 and 7 shown in Table 1, and the product to be purified after filtration through filter 7 was circulated upstream of filter 6 and filtered again through filters 6 and 7, thereby carrying out a circulating filtration process.
After the circulation and filtration process, the drug solution was placed in a container.
In addition, for Examples 85 to 88, water was added to the chemical solution so that the water content was a predetermined value.

In addition, during the series of purification processes described above, the liquid-contacting parts of the various devices that come into contact with the purified product (e.g., distillation columns, piping, storage tanks, etc.) were made of electrolytically polished stainless steel.

The organic and metal content of the chemical solution was measured using the method described below.

<Metal Component Content>
The content of metal components (metal ions, metal-containing particles) in the chemical solution was measured by a method using ICP-MS and SP-ICP-MS.
The following equipment was used:
Manufacturer: PerkinElmer
Model: NexION350S
The following analysis software was used:
· Syngistix nano application module for "SP-ICP-MS" · Syngistix for ICP-MS software However, since metal-containing particles of 10 nm or less cannot be measured by SP-ICP-MS, the above-mentioned identification method was used.

<Organic impurity content>
The content of organic impurities in each of the chemical solutions was analyzed using a gas chromatography mass spectrometry (GC/MS) device (manufactured by Agilent, GC: 7890B, MS: 5977B EI/CI MSD).

<Test>
[Pre-wet or rinsing liquid]
The prepared chemical solutions were evaluated for their defect suppression properties when used as a pre-wet solution or a rinsing solution by the method described below.
First, the chemical solution was spin-discharged onto a silicon substrate having a diameter of 300 mm or a silicon substrate having a diameter of 300 mm with a silicon oxide film (a silicon substrate whose surface is covered with a silicon oxide film), and 0.5 cc of each chemical solution was discharged onto the surface of the substrate while rotating the substrate. The substrate was then spin-dried. Next, using a wafer inspection device "SP-5" manufactured by KLA-Tencor Corporation, the number of defects present on the substrate after the chemical solution was applied was counted (this was taken as the measured value).
Next, using EDAX (energy-dispersive X-ray spectroscopy), the types of defects were classified into metal residue defects, composite residue defects, and stain-like residue defects. Metal residue defects are residues derived from metal components, composite residue defects are residues derived from composites of organic matter and metal components, and stain-like residue defects are residues derived from organic matter.
In addition, if both the "metal residue on Si" and the "metal residue on _SiO2 " are "D" or higher, it can be suitably used as a pre-wet liquid or a rinsing liquid.

<Individual evaluation (metal residue defects, composite residue defects, stain-like residue defects)>
A: The number of corresponding defects was 20 or less per substrate.
B: The number of corresponding defects was more than 20/substrate and not more than 50/substrate.
C: The number of corresponding defects was more than 50/substrate and not more than 100/substrate.
D: The number of corresponding defects was more than 100/substrate and not more than 150/substrate.
E: The number of corresponding defects exceeded 150/substrate.

[Developer]
The prepared chemical solutions were evaluated when used as developing solutions by the method described below.
First, a resist pattern was formed by the following procedure.
An actinic ray-sensitive or radiation-sensitive resin composition described below was applied to a silicon substrate having a diameter of 300 mm or a silicon substrate having a diameter of 300 mm with a silicon oxide film, and prebaked (PB) at 100° C. for 60 seconds to form a resist film with a thickness of 150 nm.

(Actinic ray-sensitive or radiation-sensitive resin composition)
Acid-decomposable resin (resin represented by the following formula (weight average molecular weight (Mw): 7500); the numerical values shown for each repeating unit represent mol %): 100 parts by mass

Photoacid generator as shown below: 8 parts by weight

Quencher shown below: 5 parts by weight (mass ratio, from left to right, was 0.1:0.3:0.3:0.2). Of the quenchers shown below, the polymer type quencher has a weight average molecular weight (Mw) of 5000. The numerical values listed for each repeating unit indicate the molar ratio.

Hydrophobic resin shown below: 4 parts by weight (the mass ratio, from left to right, was 0.5:0.5). Note that of the hydrophobic resins shown below, the hydrophobic resin on the left has a weight average molecular weight (Mw) of 7000, and the hydrophobic resin on the right has a weight average molecular weight (Mw) of 8000. Note that in each hydrophobic resin, the numerical value listed for each repeating unit indicates the molar ratio.

solvent:
PGMEA (propylene glycol monomethyl ether acetate): 3 parts by mass Cyclohexanone: 600 parts by mass γ-BL (γ-butyrolactone): 100 parts by mass

The wafer on which the resist film was formed was subjected to pattern exposure at 25 mJ/ ^cm2 using an ArF excimer laser scanner (Numerical Aperture: 0.75). Then, it was heated at 120°C for 60 seconds. Then, it was paddled with each developer (chemical solution) for 30 seconds and developed. Then, the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds to form a negative resist pattern. Then, the obtained negative resist pattern was heated at 200°C for 300 seconds. Through the above process, an L/S pattern (average pattern width: 45 nm) with a line/space of 1:1 was obtained.
The space portions of the obtained samples were evaluated for the presence or absence of the above-mentioned metal residue defects, composite residue defects, and stain-like residue defects according to the above-mentioned methods.

In each example, the pressure difference between the filters was 0.01 to 0.03 MPa.
In Table 1, "Application 1" in the "Application" column means that the above test was performed using the chemical solution described in each Example and Comparative Example as a pre-wet liquid and a rinse liquid. "Application 2" in the "Application" column means that the above test was performed using the chemical solution described in each Example and Comparative Example as a developer.
In the table, "metal residue on Si" shows the evaluation results of metal residue defects on silicon substrates, "composite residue on Si" shows the evaluation results of composite residue defects on silicon substrates, "stain-like residue on Si" shows the evaluation results of stain-like residue defects on silicon substrates, "metal residue on _SiO2 " shows the evaluation results of metal residue defects on silicon substrates with silicon oxide films, and "composite residue on _SiO2 " shows the evaluation results of composite residue defects on silicon substrates with silicon oxide films.

In Table 1, the "Ti oxide particle/Ti ion" column represents the mass ratio of the titanium oxide particle content to the titanium ion content. The "Ti ion amount (ppt by mass)" column represents the titanium ion content (ppt by mass) relative to the total mass of the chemical solution. The "Fe oxide particle/Fe ion" column represents the mass ratio of the iron oxide particle content to the iron ion content. The "Fe ion amount (ppt by mass)" column represents the iron ion content (ppt by mass) relative to the total mass of the chemical solution. The "Al oxide particle/Al ion" column represents the mass ratio of the aluminum oxide particle content to the aluminum ion content. The "Al ion amount (ppt by mass)" column represents the aluminum ion content (ppt by mass) relative to the total mass of the chemical solution. The "Ti oxide particle ratio (% by mass)" column represents the titanium oxide particle content (% by mass) relative to the titanium component content in the metal component. The "Fe oxide particle ratio (% by mass)" column represents the iron oxide particle content (% by mass) relative to the iron component content in the metal component. The column "Ratio of Al oxide particles (mass %)" indicates the content (mass %) of aluminum oxide particles relative to the content of aluminum components in the metal components. The column "Ratio of Ti oxide particles of 0.5-17 nm (mass %)" indicates the content (mass %) of titanium oxide particles having a particle diameter of 0.5 to 17 nm. The column "Ratio of Fe oxide particles of 0.5-17 nm (mass %)" indicates the content (mass %) of iron oxide particles having a particle diameter of 0.5 to 17 nm. The column "Ratio of Al oxide particles of 0.5-17 nm (mass %)" indicates the content (mass %) of aluminum oxide particles having a particle diameter of 0.5 to 17 nm. The column "Ratio of Cu oxide particles (mass %)" indicates the content (mass %) of copper oxide particles relative to the content of copper components in the metal components. The column "Ratio of Cu oxide particles of 0.5-17 nm (mass %)" indicates the content (mass %) of copper oxide particles having a particle diameter of 0.5 to 17 nm. The "moisture content" column indicates the water content (mass ppb) in the chemical solution relative to the total mass of the chemical solution.
In addition, in Table 1, "E+number" represents "10 ^numbers ", for example, "3.5E+04" represents "3.5×10 ⁴ ".
In Table 1, ">99" means more than 99. "<1" means less than 1.
In Table 1, "<500 ppb" means less than 500 ppb by mass.

In Table 1, the data relating to each Example and Comparative Example are shown in each row of Table 1 [Part 1] <1> to <6>, Table 1 [Part 2] <1> to <6>, Table 1 [Part 3] <1> to <6>, and Table 1 [Part 4] <1> to <6>.
For example, in Example 1, as shown in Table 1 [Part 1] <1>, CyHe was used as the organic solvent, as shown in Table 1 [Part 1] <2>, Filter 2 was "IEX 15 nm", as shown in Table 1 [Part 1] <3>, Ti oxide particles/Ti ions in the chemical solution were 3.5E+04, as shown in Table 1 [Part 1] <4>, the amount of Al ions was 32 ppt by mass, as shown in Table 1 [Part 1] <5>, the ratio of Fe oxide particles of 0.5-17 nm was 81% by mass, and as shown in Table 1 [Part 1] <6>, "metal residue on Si" was "A". The same applies to the other Examples and Comparative Examples.

From the results shown in the table, it was confirmed that the chemical solution of the present invention can obtain the desired effects.
In particular, a comparison of Examples 1 to 8 confirmed that when the mass ratio of the titanium oxide particle content to the titanium ion content was 10 ¹ to 10 ¹⁰ , a more excellent effect was obtained.
Furthermore, it was confirmed from Examples 9 and 10 that when the mass ratio of the content of iron oxide particles to the content of iron ions was 10 ⁰ to 10 ¹² , a more excellent effect was obtained.
Furthermore, it was confirmed from Examples 11 and 12 that when the mass ratio of the content of aluminum oxide particles to the content of aluminum ions was 10 ⁰ to 10 ¹² , a more excellent effect was obtained.
Furthermore, from Examples 13 and 14 (34 and 35, 55 and 56, 76 and 77), it was confirmed that the effect was better when the content of titanium ions (or iron ions, aluminum ions) was 0.10 to 100 ppt by mass relative to the total mass of the chemical solution.
Furthermore, it was confirmed from Examples 16 and 17 (37 and 38, 58 and 59, 79 and 80) that the effect was superior when the content of titanium oxide particles (or iron oxide particles, aluminum oxide particles) was 5 mass % or more and less than 99 mass % relative to the content of titanium component in the metal component.
Furthermore, it was confirmed from Examples 18 and 19 (39 and 40, 60 and 61, 81 and 82) that the effect was superior when the proportion of particles having a particle size of 0.5 to 17 nm among the titanium oxide particles (or iron oxide particles, aluminum oxide particles) was 60 mass % or more and less than 98 mass %.
Furthermore, it was confirmed from Examples 20 and 21 (41 and 42, 62 and 63, 83 and 84) that the effect was superior when the content of organic impurities was 1,000 to 100,000 ppt by mass relative to the total mass of the chemical solution.

The chemical solution of Example 22 (100 L) was used to wash a container (EP-SUS) and various devices used in <Purification Procedure>, and then the chemical solution of Example 22 separately prepared was passed through the above-mentioned washed devices and recovered in the washed container, thereby obtaining a solution A in the container.
In addition, the chemical solution (100 L) of Example 38 was used to wash a container (EP-SUS) and various devices used in <Purification Procedure>, and then the chemical solution of Example 22, which had been separately prepared, was passed through the above-mentioned washed devices and recovered in the washed container, thereby obtaining a solution B in the container.
When "metal residue defects on Si" were evaluated using solutions A and B, solution A gave better results.

Example (EUV Exposure)
First, resist composition 1 was obtained by mixing the components in the following ratio.
・Resin (A-1): 0.77g
Photoacid generator (B-1): 0.03 g
Basic compound (E-3): 0.03 g
PGMEA (commercially available, high purity grade): 67.5 g
Ethyl lactate (commercially available, high purity grade): 75g

Resin (A-1)
As the resin (A-1), the following resin was used.

Photoacid generator (B-1)
As the photoacid generator (B-1), the following compound was used.

Basic compound (E-3)
As the basic compound (E-3), the following compound was used.

(Pattern formation and evaluation)
First, resist composition 1 was applied onto a silicon wafer having a diameter of 300 mm, and baked (prebake: PB) at 100° C. for 60 seconds to form a resist film having a thickness of 30 nm.

This resist film was exposed through a reflective mask using an EUV exposure machine (manufactured by ASML; NXE3350, NA 0.33, Dipole 90°, outer sigma 0.87, inner sigma 0.35). Then, it was heated at 85° C. for 60 seconds (PEB: Post Exposure Bake). Next, a developer (butyl acetate/manufactured by FETW) was sprayed for 30 seconds by the spray method to develop, and a rinse solution was discharged onto the silicon wafer for 20 seconds by the spin coating method to rinse. Next, the silicon wafer was rotated at a rotation speed of 2000 rpm for 40 seconds to form a line-and-space pattern with a space width of 20 nm and a pattern line width of 15 nm.
The rinsing solutions used were the same as those used in Example 44. When the above-mentioned various evaluations were carried out, the desired effects with the same tendencies as those shown in Table 1 were obtained.

Claims (21)

a resist film forming step of forming a resist film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition;
an exposure step of exposing the resist film to light;
a developing step of developing the exposed resist film to form a resist pattern,
at least one selected from the group consisting of a developing solution used in the developing step, a pre-wetting solution used in pre-wetting the substrate before the resist film forming step, and a rinsing solution used in rinsing the substrate having the resist pattern after the developing step is a chemical solution containing an organic solvent and a metal component,
The metal component contains titanium oxide particles and titanium ions,
a mass ratio of the content of the titanium oxide particles to the content of the titanium ions is 10 ¹ to 10 ⁷ ;
The content of the titanium ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution. The pattern forming method according to claim 1, wherein the content of the titanium oxide particles is 5% by mass or more and less than 99% by mass relative to the content of the titanium component in the metal component. The pattern forming method according to claim 1 or 2, wherein the proportion of particles having a particle size of 0.5 to 17 nm among the titanium oxide particles is 60% by mass or more and less than 98% by mass. The metal component contains iron ions,
4. The pattern formation method according to claim 1, wherein the content of the iron ions is 0.10 to 100 ppt by mass with respect to the total mass of the chemical solution. the metal component comprises iron oxide particles;
5. The pattern formation method according to claim 1, wherein the content of the iron oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the iron component in the metal component. the metal component comprises iron oxide particles;
6. The pattern formation method according to claim 1, wherein a ratio of particles having a particle diameter of 0.5 to 17 nm to the iron oxide particles is 60% by mass or more and less than 98% by mass. The metal component contains iron oxide particles and iron ions,
7. The pattern formation method according to claim 1, wherein a mass ratio of a content of said iron oxide particles to a content of said iron ions is ^10.sup.0 to ^10.sup.12 . The metal component contains aluminum ions,
8. The pattern formation method according to claim 1, wherein the content of the aluminum ions is 0.10 to 100 ppt by mass with respect to the total mass of the chemical solution. the metal component contains aluminum oxide particles;
9. The pattern formation method according to claim 1, wherein the content of the aluminum oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the aluminum component in the metal component. the metal component contains aluminum oxide particles;
The chemical solution according to any one of claims 1 to 9, wherein a ratio of particles having a particle diameter of 0.5 to 17 nm among the aluminum oxide particles is 60 mass % or more and less than 98 mass %. The metal component contains aluminum oxide particles and aluminum ions,
11. The pattern formation method according to claim 1, wherein a mass ratio of a content of said aluminum oxide particles to a content of said aluminum ions is ^10.sup.0 to ^10.sup.12 . The metal component contains copper oxide particles,
The pattern forming method according to any one of claims 1 to 11, wherein the content of the copper oxide particles is 5 mass % or more and less than 99 mass % with respect to the content of the copper component in the metal component. The metal component contains copper oxide particles,
The pattern formation method according to any one of claims 1 to 12, wherein a ratio of particles having a particle diameter of 0.5 to 17 nm to the copper oxide particles is 60 mass % or more and less than 98 mass %. The metal component contains copper oxide particles and copper ions,
14. The pattern formation method according to claim 1, wherein a mass ratio of a content of said copper oxide particles to a content of said copper ions is ^10.sup.0 to ^10.sup.12 . a resist film forming step of forming a resist film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition;
an exposure step of exposing the resist film to light;
a developing step of developing the exposed resist film to form a resist pattern,
at least one selected from the group consisting of a developing solution used in the developing step, a pre-wetting solution used in pre-wetting the substrate before the resist film forming step, and a rinsing solution used in rinsing the substrate having the resist pattern after the developing step is a chemical solution containing an organic solvent and a metal component,
the metal component contains titanium oxide particles, titanium ions, iron ions, iron oxide particles, aluminum ions, aluminum oxide particles, copper oxide particles, and copper ions;
a mass ratio of the content of the titanium oxide particles to the content of the titanium ions is 10 ⁰ to 10 ⁷ ;
The content of the titanium ion is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution,
The content of the iron ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution,
the content of the iron oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the iron component in the metal component,
The content of the aluminum ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution,
the content of the aluminum oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the aluminum component in the metal component,
The content of the copper oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the copper component in the metal component,
A pattern forming method, wherein a mass ratio of a content of the copper oxide particles to a content of the copper ions is 10 ⁰ to 10 ¹² . In addition, it contains organic impurities,
16. The pattern formation method according to claim 1, wherein the content of the organic impurities is 1,000 to 100,000 ppt by mass with respect to the total mass of the chemical solution. The pattern formation method according to any one of claims 1 to 16, wherein the content of water relative to the total mass of the chemical solution is 500 mass ppb or less. The pattern formation method according to any one of claims 1 to 17, wherein the organic solvent includes at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclohexanone, ethyl lactate, propylene carbonate, isopropanol, 4-methyl-2-pentanol, butyl acetate, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl methoxypropionate, cyclopentanone, γ-butyrolactone, diisoamyl ether, isoamyl acetate, dimethyl sulfoxide, N-methylpyrrolidone, diethylene glycol, ethylene glycol, dipropylene glycol, propylene glycol, ethylene carbonate, sulfolane, cycloheptanone, 2-heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, and undecane. the organic solvent is butyl acetate;
The pattern formation method according to any one of claims 1 to 18, wherein the developer is the chemical solution. a resist film forming step of forming a resist film on a substrate using an actinic ray-sensitive or radiation-sensitive resin composition;
an exposure step of exposing the resist film to light;
a developing step of developing the exposed resist film to form a resist pattern,
The developer used in the developing step is a chemical solution containing an organic solvent and a metal component,
the organic solvent is butyl acetate;
The metal component contains titanium oxide particles and titanium ions,
a mass ratio of the content of the titanium oxide particles to the content of the titanium ions is 10 ⁰ to 10 ⁷ ;
The content of the titanium ions is 0.10 to 100 ppt by mass relative to the total mass of the chemical solution. the organic solvent comprises at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, cyclohexanone, ethyl lactate, propylene carbonate, isopropanol, 4-methyl-2-pentanol, propylene glycol monopropyl ether, methyl methoxypropionate, cyclopentanone, γ-butyrolactone, diisoamyl ether, isoamyl acetate, dimethyl sulfoxide, N-methylpyrrolidone, diethylene glycol, ethylene glycol, dipropylene glycol, propylene glycol, ethylene carbonate, sulfolane, cycloheptanone, 2-heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, and undecane;
The pattern formation method according to any one of claims 1 to 18, wherein the pre-wet liquid or the rinsing liquid is the chemical liquid.