JP7416883B2 - Chemical liquid, chemical liquid container - Google Patents

Description

The present invention relates to a drug solution and a drug solution container.

When manufacturing semiconductor devices through wiring formation processes including photolithography, pre-wetting liquid, resist liquid (resist film forming composition), developer, rinsing liquid, stripping liquid, chemical mechanical polishing (CMP) are used. A chemical solution containing water and/or an organic solvent is used as a slurry, a cleaning solution after CMP, or a diluent thereof.
In recent years, advances in photolithography technology have led to miniaturization of patterns. As a technique for pattern miniaturization, attempts have been made to form patterns using ultraviolet rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet), and the like as exposure light sources.
With the miniaturization of formed patterns, the above-mentioned chemical solutions used in this process are required to have further defect suppression properties.

As a chemical solution used in conventional pattern formation, Patent Document 1 describes ``A method for producing an organic treatment liquid for patterning a chemically amplified resist film that can reduce the generation of particles in pattern formation technology (paragraph [0010] )” are disclosed.

JP2015-084122A

On the other hand, in recent years, when a silicon substrate or a silicon substrate with a silicon oxide film (a silicon substrate whose surface is covered with a silicon oxide film) is brought into contact with a chemical solution, metal residues are formed on the silicon substrate or a silicon substrate with a silicon oxide film. There is a need for chemical solutions that are less likely to cause defects.
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 liquid medicine container.

As a result of intensive studies to solve the above problems, the present inventors found that the above problems could 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 in which the mass ratio of the content of titanium oxide particles to the content of titanium ions is 10 ⁰ to 10 ¹² .
(2) The chemical liquid according to (1), wherein the content of titanium ions is 0.10 to 100 mass ppt based on the total mass of the chemical liquid.
(3) The chemical solution according to (1) or (2), wherein the content of titanium oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the titanium component in the metal component.
(4) The chemical solution according to any one of (1) to (3), 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.
(5) The metal component contains iron ions,
The chemical liquid according to any one of (1) to (4), wherein the content of iron ions is 0.10 to 100 mass ppt based on the total mass of the chemical liquid.
(6) the metal component contains iron oxide particles,
The chemical solution according to any one of (1) to (5), wherein the content of 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.
(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% by mass or more and less than 98% by 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 iron oxide particles to the content of iron ions is 10 ⁰ to 10 ¹² .
(9) The metal component contains aluminum ions,
The chemical liquid according to any one of (1) to (8), wherein the content of aluminum ions is 0.10 to 100 mass ppt based on the total mass of the chemical liquid.
(10) The metal component contains aluminum oxide particles,
The chemical solution according to any one of (1) to (9), wherein the content of 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.
(11) The metal component contains aluminum oxide particles,
The chemical solution according to any one of (1) to (10), wherein the proportion of particles having a particle size of 0.5 to 17 nm among the aluminum oxide particles is 60% by mass or more and less than 98% by 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 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 particles having a particle size of 0.5 to 17 nm among the copper oxide particles is 60% by mass or more and less than 98% by 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) Furthermore, it contains organic impurities,
The chemical liquid according to any one of (1) to (15), wherein the content of organic impurities is 1000 to 100000 ppt by mass based on the total mass of the chemical liquid.
(17) The chemical solution according to any one of (1) to (16), wherein the water content based on the total mass of the drug solution is 500 mass ppb or less.
(18) The organic solvent is 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 drug solution according to any one of (1) to (17).
(19) A drug solution container containing a container and the drug solution according to any one of (1) to (18) housed in the container.

According to the present invention, it is possible to provide a chemical solution that is unlikely 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 liquid medicine container can be provided.

The present invention will be explained in detail below.
Although the description of the constituent elements described below may be made based on typical embodiments of the present invention, the present invention is not limited to such embodiments.
In this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as the lower limit and upper limit.
In addition, in the present invention, "ppm" means "parts-per-million (10 ^-6 )", "ppb" means "parts-per-billion (10 ^-9 )", and "ppt""parts-per-trillion (10 ^-12 )" and "ppq" mean "parts-per-quadrillion (10 ^-15 )".
In addition, in the description of groups (atomic groups) in the present invention, descriptions that do not indicate substituted or unsubstituted include groups containing a substituent as well as groups without a substituent, to the extent that the effects of the present invention are not impaired. Also includes. For example, the term "hydrocarbon group" includes not only a hydrocarbon group without a substituent (unsubstituted hydrocarbon group) but also a hydrocarbon group containing a substituent (substituted hydrocarbon group). This point also applies to each compound.
Moreover, "radiation" in the present invention means, for example, far ultraviolet rays, extreme ultraviolet (EUV), X-rays, or electron beams. Furthermore, in the present invention, light means actinic rays or radiation. Unless otherwise specified, "exposure" in the present invention includes not only exposure with deep ultraviolet rays, X-rays, EUV, etc., but also drawing with particle beams such as electron beams or ion beams.

Although the mechanism by which the above-mentioned problems are solved by the drug solution of the present invention is not necessarily clear, the inventor speculates about the mechanism as follows. Note that the following mechanisms are speculations, and even if the effect of the present invention is obtained by a different mechanism, it is included within the scope of the present invention.
The present inventors discovered that when a chemical solution contains titanium oxide particles and titanium ions, a silicon substrate or a silicon substrate with a silicon oxide film (hereinafter, these are It is known that the likelihood of metal residue defects (residues derived from metal components) occurring on substrates (also collectively referred to as "specific substrates") differs. More specifically, if the mass ratio is too large, in other words, if the proportion of titanium oxide particles is too large, it is considered that metal residue defects derived from titanium oxide particles tend to increase on a specific substrate. In addition, if the above mass ratio is too small, in other words, if the proportion of titanium ions is too large, redox reactions will easily proceed with other metal ions that are more base than titanium ions, and particles of other metals will (For example, oxide particles of other metals) increases, and it is considered that metal residue defects tend to increase on a specific substrate.

The chemical solution of the present invention is a chemical solution containing an organic solvent and a metal component, where the metal component contains titanium oxide particles and titanium ions, and the content of titanium oxide particles is smaller than the content of titanium ions. The mass ratio is 10 ⁰ to 10 ¹² .
Hereinafter, the components contained in the drug solution of the present invention will be explained in detail.

<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 term "organic solvent" refers to a liquid organic compound contained in an amount exceeding 10,000 ppm by mass per component based on the total mass of the chemical solution. That is, in this specification, a liquid organic compound contained in an amount exceeding 10,000 mass ppm based on the total mass of the chemical solution corresponds to an organic solvent.
Moreover, in this specification, liquid means being liquid at 25° C. and under 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, and still more preferably 99.90% by mass or more based on the total mass of the chemical solution. Preferably, more than 99.95% by weight is particularly preferred. The upper limit is less than 100% by mass.
The organic solvents may be used alone or in combination of two or more. When using two or more types of organic solvents, the total content is preferably within the above range.

The type of organic solvent is not particularly limited, and any known organic solvent can be used. Examples of organic solvents include alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, lactic acid alkyl esters, alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 10 carbon atoms), and monoketone compounds that may have a ring. (preferably having 4 to 10 carbon atoms), alkylene carbonate, alkoxy alkyl acetate, alkyl pyruvate, dialkyl sulfoxide, cyclic sulfone, dialkyl ether, monohydric alcohol, glycol, acetic alkyl ester, and N-alkylpyrrolidone. .

Examples of organic solvents include 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- One member selected from the group consisting of methylpyrrolidone, diethylene glycol, ethylene glycol, dipropylene glycol, propylene glycol, ethylene carbonate, sulfolane, cycloheptanone, 2-heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, and undecane. The above is preferable.
Examples of using two or more types of organic solvents include the combination of PGMEA and PGME, and the combination of PGMEA and PC.
Note that the type and content of the organic solvent in the chemical solution can be measured using a gas chromatograph mass spectrometer.

<Metal component>
The chemical solution contains metal components.
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 only need to contain metal atoms, and include, for example, metal oxide particles, metal nitride particles, and metal particles. Note that metal particles mean particles made of metal.

The metal component contained in the chemical solution includes titanium oxide particles and titanium ions.
The mass ratio of the content of titanium oxide particles to the content of titanium ions is 10 ⁰ to 10 ¹² , and metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. The above 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 content of titanium ions is not particularly limited, and is often 0.01 to 150 ppt by mass. Among them, the content of titanium ions should be 0.10 to 100 mass ppt based on the total mass of the chemical solution, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. is preferable, and 1.0 to 70 mass ppt is more preferable.

The content of titanium oxide particles is not particularly limited, and is often 1% by mass or more and less than 100% by mass with respect to the content of the titanium component in the metal component. Among them, the content of titanium oxide particles is lower than the content of titanium components in the metal components, in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably 5% by mass or more and less than 99% by mass, more preferably 30 to 90% by mass.
The titanium component is a component containing titanium atoms, and includes 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 only need to contain titanium atoms, and include, for example, titanium oxide particles, titanium nitride particles, and titanium particles. Note that the titanium particles mean particles made of metallic titanium.

Among the titanium oxide particles, the proportion of 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. Among the titanium oxide particles, the ratio of particles with a particle size of 0.5 to 17 nm is 60%, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably at least 98% by mass, and more preferably from 60 to 95% by mass.

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 based on the total mass of the chemical solution. Among them, the content of iron ions is 0.1 to 100 mass ppt based on the total mass of the chemical solution, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. is preferable, and 1.0 to 90 mass ppt is more preferable.

The metal component contained in the chemical solution may contain iron oxide particles.
The content of iron oxide particles is not particularly limited, and is often 1% by mass or more and less than 100% by mass with respect to the content of the iron component in the metal component. Among them, the content of iron oxide particles is lower than the content of iron components in the metal components, in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably 5% by mass or more and less than 99% by mass, more preferably 10 to 95% by mass.
The iron component is a component containing iron atoms, and includes iron-containing particles and iron ions. For example, when referring to the content of the iron component, it refers to the total content of the iron-containing particles and iron ions.
The iron-containing particles only need to contain iron atoms, and include, for example, iron oxide particles, iron nitride particles, and iron particles. Note that the iron particles mean particles made of metallic iron.

Among the iron oxide particles, the proportion of 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. Among them, the ratio of particles with a particle size of 0.5 to 17 nm among iron oxide particles is 60 nm, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably at least 98% by mass, and more preferably from 60 to 95% by mass.

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 from 10 ⁻² to 10 ¹⁴ . Among these, the above mass ratio is preferably 10 ⁰ to 10 ¹² , more preferably 10 ² to 10 ¹⁰ , in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. , 10 ³ to 10 ⁸ are more preferred, and 10 ³ to 10 ⁷ are particularly preferred.

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 based on the total mass of the chemical solution. Among them, the content of aluminum ions is 0.1 to 100 mass ppt based on the total mass of the chemical solution, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. is preferable, and 1.0 to 90 mass ppt is more preferable.

The metal component contained in the chemical solution may contain aluminum oxide particles.
The content of aluminum oxide particles is not particularly limited, and is often 1% by mass or more and less than 100% by mass with respect to the content of the aluminum component in the metal component. Among them, the content of aluminum oxide particles is lower than the content of aluminum component in the metal component in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably 5% by mass or more and less than 99% by mass, more preferably 10 to 95% by mass.
The aluminum component is a component containing an aluminum atom, and includes 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 only need to contain aluminum atoms, and include, for example, aluminum oxide particles, aluminum nitride particles, and aluminum particles. Note that the aluminum particles mean particles made of metal aluminum.

Among the aluminum oxide particles, the proportion of 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. Among them, the ratio of particles with a particle size of 0.5 to 17 nm among aluminum oxide particles is 60%, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably at least 98% by mass, and more preferably from 60 to 95% by mass.

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 from 10 ⁻² to 10 ¹⁴ . Among these, the above mass ratio is preferably 10 ⁰ to 10 ¹² , more preferably 10 ² to 10 ¹⁰ , in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. , 10 ³ to 10 ⁸ are more preferred, and 10 ³ to 10 ⁷ are particularly preferred.

The metal component contained in the chemical solution may contain other metal atomic components other than those mentioned above.
Other metal atoms include, for example, 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 copper oxide particles is not particularly limited, and is often 1% by mass or more and less than 100% by mass with respect to the content of the copper component in the metal component. Among them, the content of copper oxide particles is lower than the content of the copper component in the metal component in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably 5% by mass or more and less than 99% by mass, more preferably 10 to 95% by mass.
The copper component is a component containing copper atoms, and includes 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 only need to contain copper atoms, and include, for example, copper oxide particles, copper nitride particles, and copper particles. Note that the copper particles mean particles made of metallic copper.

Among the copper oxide particles, the proportion of 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. Among them, the ratio of particles with a particle size of 0.5 to 17 nm among copper oxide particles is 60 nm, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. It is preferably at least 98% by mass, and more preferably from 60 to 95% by mass.

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 from 10 ⁻² to 10 ¹⁴ . Among these, the above mass ratio is preferably 10 ⁰ to 10 ¹² , more preferably 10 ² to 10 ¹⁰ , in that metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. , 10 ³ to 10 ⁸ are more preferred, and 10 ³ to 10 ⁷ are particularly preferred.

The metal component may be a metal component that is unavoidably included in each component (raw material) contained in the chemical solution, or a metal component that is unavoidably included during the production, storage, and/or transfer of the processing solution. , may be added intentionally.

The content of the metal component is not particularly limited, but it should be 10 to 500,000 mass based on the total mass of the chemical solution, since metal residue defects or composite residue defects described below are less likely to occur on the silicon substrate or silicon oxide film. ppt is preferred.

Note that the type and content 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 data analysis. Data analysis of the SP-ICP-MS method 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 its existing form. Therefore, the total mass of the metal-containing particles to be measured and the metal ions is quantified as the content of the metal component.

On the other hand, with the SP-ICP-MS method, the content of metal-containing particles can be measured. Therefore, by subtracting the content of metal-containing particles from the content of metal components in the sample, the content of metal ions in the sample can be calculated.
Examples of the equipment for the SP-ICP-MS method include Agilent 8800 triple quadrupole ICP-MS (inductively coupled plasma mass spectrometry, for semiconductor analysis, option #200) manufactured by Agilent Technologies, and described in Examples. It can be measured by the following method. As other devices other than the above, in addition to NexION 350S manufactured by PerkinElmer, Agilent 8900 manufactured by Agilent Technologies can also be used.

Note that 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-A No. 2009-188333 (hereinafter also referred to as "specific method") is used.
Here, the number of particles of 0.5 to 10 nm remaining on the substrate is counted by a specific method, and the converted value from SNP-ICP-MS of particles of 20 nm is used for the count. Here, 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 in SNP-ICP-MS, and the number of 20 nm titanium oxide particles remaining on the substrate calculated by a specific method is 1, the converted value becomes 10. In other words, if the number of 1 nm titanium oxide particles confirmed by the specific method is 100, it is calculated as 1000 particles (100 particles x 10) in the chemical solution based on 10 times the converted value. 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.
Although the content of organic impurities in the chemical solution is not particularly limited, it is preferably 1,000 to 100,000 ppt by mass based on the total mass of the chemical solution, since stain-like residue defects described below are less likely to occur on the silicon substrate.
Note that the organic impurity is an organic compound different from the organic solvent, and means an organic compound contained in a content of 10,000 mass ppm or less with respect to the total mass of the organic solvent. That is, in this specification, an organic compound contained in a content of 10,000 mass ppm or less based on the total mass of the organic solvent corresponds to an organic impurity and does not correspond to an organic solvent.
Organic impurities are often mixed into or added to a chemical solution during the process of purifying a substance 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. Water is not included in the above organic impurities.
The water is not particularly limited, and for example, distilled water, ion exchange water, pure water, etc. can be used.
Water may be added to the drug solution, or may be mixed into the drug solution unintentionally during the process of manufacturing the drug solution. Examples of cases where water is unintentionally mixed in the manufacturing process of a chemical solution include when water is contained in raw materials (e.g., organic solvents) used in the manufacturing process of the chemical solution, and when water is mixed in the manufacturing process of the chemical solution ( For example, contamination) etc., but are not limited to the above.

The content of water in the chemical solution is not particularly limited, but is preferably 2.0% by mass or less, more preferably 500 mass ppb or less based on the total mass of the chemical solution. The lower limit is not particularly limited, but may be 0% by mass. The water content in the chemical solution means the water content measured using a device based on the Karl Fischer water measurement method.

<Applications of chemical liquid>
The chemical solution of the present invention is preferably used for manufacturing semiconductor devices. Among these, it is preferable to manufacture semiconductor chips using the chemical solution of the present invention.
Specifically, in a semiconductor device manufacturing process that includes a lithography process, an etching process, an ion implantation process, a peeling process, etc., organic substances are treated after each process or before moving to the next process. Specifically, it is suitably used as a pre-wetting liquid, a developing liquid, a rinsing liquid, a polishing liquid, etc.
In addition, the chemical solution may also be used as a diluent (in other words, a solvent) for the resin contained in the composition for forming a resist film.

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

Among these, the chemical liquid is suitably used in a pre-wetting liquid, a developing liquid, a rinsing liquid, a polishing liquid, and a composition for forming a resist film. Among them, when applied to a pre-wet liquid, a developer, and a rinse liquid, more excellent effects are exhibited. In particular, when the exposure light source is EUV and it is applied to a pre-wet solution, a developer, and a rinse solution, more excellent effects are exhibited. Further, even when applied to a pipe cleaning liquid used for pipes used for transferring these liquids, even more excellent effects are exhibited.

<Method for producing chemical solution>
The method for producing the above chemical solution is not particularly limited, and any known production method can be used. Among these, the method for producing a chemical solution includes a filtration step in which a chemical solution is obtained by filtering a product to be purified containing an organic solvent using a filter, in that a chemical solution exhibiting better effects of the present invention can be obtained. preferable.

The substance to be purified used in the filtration process may be procured by purchase or the like, or may be obtained by reacting raw materials. The product to be purified preferably has a low content of impurities. Examples of commercial products of such products to be purified include commercial products called "high purity grade products."

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

(filtration process)
It is preferable that the method for producing a chemical solution of the present invention includes a filtration step of filtering the substance to be purified using a filter to obtain a drug solution. There are no particular restrictions on the method of filtering the object to be purified using a filter, but the method includes passing the object to be purified through a filter unit having a housing and a filter cartridge housed in the housing with or without pressure ( It is preferable to pass the liquid through.

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

It is preferable that the pore diameter of the filter is 5.0 nm or less, since the number of particles contained in the chemical solution can be more easily controlled. Hereinafter, a filter with a pore diameter of 5.0 nm or less will also be referred to as a "micropore filter."
Note that the micropore size filter may be used alone or in combination with a filter having another pore size. Among these, from the viewpoint of better productivity, it is preferable to use a filter with a larger pore diameter. That is, when two or more filters are used, it is preferable that at least one filter has a pore diameter of 5.0 nm or less. In this case, clogging of the micropore filter can be prevented by passing the product to be purified, which has been filtered in advance through a filter having a larger pore diameter, through the micropore filter.
That is, when using one filter, the pore diameter of the filter is preferably 5.0 nm or less, and when using two or more filters, the pore diameter of the filter having the smallest pore diameter is preferably 5.0 nm. The following are preferred.

Although there are no particular restrictions on the form in which two or more types of filters having different pore diameters are sequentially used, examples include a method in which the filter units described above are sequentially arranged along the pipe line through which the product to be purified is transferred. At this time, if you try to keep the flow rate of the product to be purified per unit time constant throughout the pipeline, a larger pressure may be applied to a filter with a smaller pore diameter than a filter with a larger pore diameter. . In this case, a pressure regulating valve, a damper, etc. may be placed between the filters to keep the pressure applied to the filter with a small pore diameter constant, or a filter unit containing the same filter may be placed along the pipe. It is preferable to increase the filtration area by arranging them in parallel. 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 any known material can be used as the filter material. Specifically, when the resin is a polyamide such as nylon (for example, 6-nylon and 6,6-nylon); polyolefin such as polyethylene and polypropylene; polystyrene; polyimide; polyamideimide; poly(meth)acrylate; Polymers such as polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylene propene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride Examples include fluorocarbon; polyvinyl alcohol; polyester; cellulose; cellulose acetate.
Among them, nylon (among them, 6,6-nylon is preferable), polyolefin (among them polyethylene is preferable), and polyethylene, because they have better solvent resistance and the resulting chemical solution has better defect suppression performance. At least one selected from the group consisting of (meth)acrylate and polyfluorocarbon (among them, polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA) are preferred) is preferred. These polymers can be used alone or in combination of two or more.
In addition to resin, diatomaceous earth, glass, etc. may also be used.
In addition, polymers (nylon grafted UPE, etc.), which are made by graft copolymerizing a polyamide (for example, nylon-6 or nylon-6,6, etc.) to a polyolefin (such as UPE (ultra-high molecular weight polyethylene) described below), are also used as filters. It can also be used as a material.

Further, the filter may be a surface-treated filter. The surface treatment method is not particularly limited, 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 the surface of the filter is rendered hydrophilic. The water contact angle on the surface of the filter that has been made hydrophilic by plasma treatment is not particularly limited, but the static contact angle at 25°C measured with a contact angle meter is preferably 60° or less, more preferably 50° or less, More preferably, the angle is 30° or less.

As the chemical modification treatment, a method of introducing an ion exchange group into the filter is preferred.
That is, as a filter, a filter having an ion exchange group is preferable.
Examples of ion exchange groups include cation exchange groups and anion exchange groups, examples of cation exchange groups include sulfonic acid groups, carboxy groups, phosphoric acid groups, etc., and examples of anion exchange groups include quaternary ammonium groups. Can be mentioned. The method for introducing the ion exchange group into the filter is not particularly limited, but includes a method in which a compound containing an ion exchange group and a polymerizable group is reacted with the filter to form a graft.

The method for introducing the ion exchange group is not particularly limited, but the filter is irradiated with ionizing radiation (α rays, β rays, γ 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, a polymer obtained by polymerizing this monomer is grafted onto the filter. Ion exchange groups can be introduced into the polymer by catalytically reacting the produced polymer with a compound containing an anion exchange group or a cation exchange group.

Further, the filter may be configured by combining a woven fabric or non-woven fabric in which ion-exchange groups are formed by radiation graft polymerization with a conventional glass wool, woven fabric, or non-woven filter medium.

When a filter having an ion exchange group is used, the content of metal-containing particles and metal ions in the chemical solution can be easily controlled within a desired range. The material constituting the filter having an ion exchange group is not particularly limited, but includes 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 diameter of the filter having an ion exchange group is not particularly limited, but is preferably 1 to 30 nm, more preferably 5 to 20 nm. The filter having an ion exchange group may also serve as the filter having the minimum pore size described above, or may be used separately from the filter having the minimum pore size. Among them, the filtration process uses a filter that has an ion exchange group and a filter that does not have an ion exchange group and has the smallest pore size, since it is possible to obtain a chemical solution that exhibits the better effects of the present invention. is preferred.
The material for the filter having the minimum pore diameter described above is not particularly limited, but from the viewpoint of solvent resistance etc., it is generally preferable to use at least one member selected from the group consisting of polyfluorocarbons and polyolefins, and polyolefins are preferred. More preferred.

Therefore, as the filter used in the filtration step, two or more types of filters made of different materials may be used. For example, filters made of polyolefin, polyfluorocarbon, polyamide, and materials with ion exchange groups introduced into these materials may be used. You may use two or more types selected from the group consisting of:

- 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 a filter means the pore size distribution, the positional distribution of pores in the filter, the shape of pores, etc., and is typically controlled by the filter manufacturing method. It is possible.
For example, a porous membrane can be obtained by sintering a powder such as a resin, and a fibrous membrane can be obtained by forming by a method such as electrospinning, electroblowing, or melt blowing. These have different pore structures.

A "porous membrane" is a membrane that retains components in the object to be purified, such as gels, particles, colloids, cells, and polyoligomers, but components that are substantially smaller than the pores pass through the pores. means. Retention of components in the product to be purified by a porous membrane may depend on operating conditions, such as surface velocity, surfactant use, pH, and combinations thereof, and the pore size of the porous membrane; It may depend on the structure and the size and structure of the particles to be removed (hard particles or gels, etc.).

If the product to be purified contains negatively charged particles, a polyamide filter acts as a non-sieving membrane to remove such particles. Typical non-sieving membranes include, but are not limited to, nylon membranes, such as nylon-6 membranes and nylon-6,6 membranes.
As used herein, "non-sieving" retention mechanisms refer to retention caused by mechanisms such as obstruction, diffusion, and adsorption that are not related to filter pressure drop or pore size.

Non-sieving retention includes retention mechanisms such as obstruction, diffusion, and adsorption that remove particles to be removed in the purified product regardless of filter pressure drop or filter pore size. Adsorption of particles to the filter surface can be mediated by, for example, intermolecular van der Waals forces and electrostatic forces. A jamming effect occurs when particles moving through a non-sieving membrane layer with a serpentine path cannot change direction quickly enough to avoid contacting the non-sieving membrane. Particle transport by diffusion arises primarily from random or Brownian motion of small particles, which creates a certain probability that the particles will collide with the filter media. Non-sieving retention mechanisms can become active when there is no repulsive force between the particles and the filter.

UPE (ultra high molecular weight polyethylene) filters are typically sieve membranes. Sieve membrane refers to a membrane that primarily traps particles through a sieve retention mechanism, or a membrane that is optimized for trapping particles through a sieve retention mechanism.
Typical examples of sieve membranes include, but are not limited to, polytetrafluoroethylene (PTFE) membranes and UPE membranes.
Note that the term "sieve retention mechanism" refers to the retention of results due to the particles to be removed being larger than the pore diameter of the porous membrane. Sieve retention is improved by forming a filter cake (agglomeration of particles to be removed at the surface of the membrane). 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 that can form a fiber membrane. Examples of the polymer include polyamide. Examples of the polyamide include nylon 6 and nylon 6,6. The polymer forming the fiber membrane may be poly(ether sulfone). When the fibrous membrane is on the primary side of the porous membrane, the surface energy of the fibrous membrane is preferably higher than the polymer of which the porous membrane is on the secondary side. Such a combination includes, for example, a case where the fiber membrane material is nylon and the porous membrane is 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 (for example, a porous membrane containing UPE, PTFE, etc.) is not particularly limited, but the shape of the pores may include, for example, a lace shape, a string shape, a node shape, etc. It will be done.
The size distribution of pores in the porous membrane and the distribution of their positions in the membrane are not particularly limited. The size distribution may be smaller and the distribution position in the film may be symmetrical. Alternatively, the size distribution may be larger and the distribution position within the membrane may be asymmetric (the above membrane is also referred to as an "asymmetric porous membrane"). In asymmetric porous membranes, the pore size varies throughout the membrane, typically increasing in pore size from one surface of the membrane to the other surface of the membrane. At this time, the surface on the side with many large pores is called the "open side", and the surface on the side with many small pores is also called the "tight side".
Examples of asymmetric porous membranes include membranes in which the size of pores is smallest at a certain position within the thickness of the membrane (this is also referred to as an "hourglass shape").

By using an asymmetric porous membrane with larger sized pores on the primary side, in other words, when the primary side is open, a pre-filtration effect can be created.

The porous membrane may include thermoplastic polymers such as PESU (polyether sulfone), PFA (perfluoroalkoxyalkane, copolymer of tetrafluoroethylene and perfluoroalkoxyalkane), polyamide, and polyolefin. , polytetrafluoroethylene, etc.
Among these, ultra-high molecular weight polyethylene is preferred as the material for the porous membrane. Ultra-high molecular weight polyethylene refers to thermoplastic polyethylene with extremely long chains, with a molecular weight of 1 million or more, typically 2 to 6 million being preferred.

As the filter used in the filtration step, two or more types of filters having different pore structures may be used, and a porous membrane filter and a fibrous 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.

Further, it is preferable to thoroughly wash the filter before use.
When using an unwashed filter (or a filter that has not been sufficiently washed), impurities contained in the filter are likely to be introduced into the chemical solution.

As described above, in the filtration process according to the embodiment of the present invention, a purified product is passed through two or more types of filters that differ in at least one type selected from the group consisting of filter material, pore size, and pore structure. It may be a multi-stage filtration process.
Further, the product to be purified may be passed through the same filter multiple times, or may be passed through multiple filters of the same type.

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

There are no particular restrictions on the material of the liquid-contacted parts of the purification equipment used in the filtration process (meaning the inner wall surface, etc. that may come into contact with the product to be purified and the chemical solution), but non-metallic materials (fluorine resins, etc.) are not particularly limited. etc.) and electrolytically polished metal materials (stainless steel, etc.) (hereinafter, these are also collectively referred to as "corrosion-resistant materials"). For example, when the wetted parts of a production tank are made of a corrosion-resistant material, it means that the production tank itself is made of a corrosion-resistant material, or that the inner wall surface of the production tank is coated with a corrosion-resistant material. Can be mentioned.

The non-metallic material is not particularly limited, and known materials can be used.
Examples of nonmetallic materials include polyethylene resin, polypropylene resin, polyethylene-polypropylene resin, and fluorine-based resins (e.g., tetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene - Hexafluoropropylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluorochloroethylene-ethylene copolymer resin, vinylidene fluoride resin, trifluorochloride ethylene copolymer resin, and vinyl fluoride resin etc.), but is not limited thereto.

The metal material is not particularly limited, and known materials can be used.
Examples of the metal material include metal materials in which the total content of chromium and nickel is more than 25% by mass based on the total mass of the metal material, and among them, 30% by mass or more is more preferable. The upper limit of the total content of chromium and nickel in the metal material is not particularly limited, but is generally preferably 90% by mass or less.
Examples of the metal material include stainless steel and nickel-chromium alloy.

The stainless steel is not particularly limited, and any known stainless steel can be used. Among these, alloys containing 8% by mass or more of nickel are preferred, and austenitic stainless steels containing 8% by mass or more of nickel are more preferred. 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 these, a nickel-chromium alloy having a nickel content of 40 to 75% by mass and a chromium content of 1 to 30% by mass is preferred.
Examples of the nickel-chromium alloy include Hastelloy (trade name, the same below), Monel (trade name, the same below), and Inconel (trade name, the same below). More specifically, Hastelloy C-276 (Ni content 63% by mass, Cr content 16% by mass), Hastelloy-C (Ni content 60% by mass, Cr content 17% by mass), and Hastelloy C- No. 22 (Ni content: 61% by mass, Cr content: 22% by mass).
Further, the nickel-chromium alloy may further contain boron, silicon, tungsten, molybdenum, copper, cobalt, etc. in addition to the above-mentioned alloys, if necessary.

The method for electrolytically polishing a metal material is not particularly limited, and any known method can be used. For example, the methods described in paragraphs [0011] to [0014] of JP2015-227501A and paragraphs [0036] to [0042] of JP2008-264929A can be used.

It is presumed that the chromium content in the passive layer on the surface of the metal material is greater than the chromium content in the matrix due to electrolytic polishing. Therefore, it is presumed that if a refining device in which the liquid contact part is made of an electrolytically polished metal material is used, metal-containing particles are less likely to flow out into the object to be purified.
Note that the metal material may be buffed. The buffing method is not particularly limited, and any known method can be used. The size of the abrasive grains used for finishing buff polishing is not particularly limited, but it is preferably #400 or less because it tends to reduce the unevenness on the surface of the metal material. Note that buffing is preferably performed before electrolytic polishing.

(Other processes)
The method for producing a chemical solution may further include steps other than the filtration step. Examples of processes other than the filtration process include a distillation process, a reaction process, and a static elimination process.

(distillation process)
The distillation process is a process in which a purified product containing an organic solvent is distilled to obtain a distilled purified product. The method for distilling the product to be purified is not particularly limited, and any known method can be used. Typically, there is a method in which a distillation column is placed on the primary side of a purification device used for the filtration process, and the distilled product to be purified is introduced into a production tank.
At this time, the liquid contact part of the distillation column is not particularly limited, but it is preferably formed of the corrosion-resistant material described above.

(Reaction process)
The reaction step is a step of reacting raw materials to produce a purified product containing an organic solvent as a reactant. The method for producing the product to be purified is not particularly limited, and any known method can be used. Typically, there is a method in which a reaction tank is placed on the primary side of a production tank (or distillation column) of a purification device used for the filtration process, and a reactant is introduced into the production tank (or distillation column).
At this time, the liquid contact part of the production tank is not particularly limited, but it is preferably formed of the corrosion-resistant material described above.

(static elimination process)
The static elimination process is a process in which static electricity is removed from the object to be purified to reduce the charged potential of the object to be purified.
The static elimination method is not particularly limited, and any known static elimination method can be used. Examples of the static elimination method include a method of bringing the object to be purified into contact with a conductive material.
The contact time for bringing the product to be purified into contact 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. Conductive materials include stainless steel, gold, platinum, diamond, and glassy carbon.
Examples of methods for bringing the substance to be purified into contact with the conductive material include a method in which a grounded mesh made of a conductive material is placed inside the conduit and the substance to be purified is passed through the mesh.

It is preferable that all of the accompanying purification of the product, such as opening of containers, cleaning of containers and equipment, storage of solutions, and analysis, be performed 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 ISO 14644-1:2015 defined by the International Organization for Standardization. Specifically, it is preferable to satisfy any of ISO class 1, ISO class 2, ISO class 3, and ISO class 4, more preferably to satisfy ISO class 1 or ISO class 2, and it is more preferable to satisfy ISO class 1. is even more preferable.

The storage temperature of the chemical solution is not particularly limited, but the storage temperature is preferably 4° C. or higher, since impurities etc. contained in trace amounts of the drug solution are more difficult to elute, and as a result, better effects of the present invention can be obtained.

<Medical solution container>
The chemical solution produced by the above purification method may be stored in a container until used.
Such a container and the medicinal solution contained in the container are collectively referred to as a medicinal solution container. The medicinal solution is taken out and used from the stored medicinal solution container.

As a container for storing the above-mentioned chemical solution, it is preferable that the inside of the container has a high degree of cleanliness and that there is little elution of impurities for use in semiconductor device manufacturing.
Specific examples of containers that can be used include, but are not limited to, the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industries.

As a container, use a multi-layer bottle with a 6-layer structure made of 6 types of resin on the inner wall of the container, or a multi-layer bottle with a 7-layer structure made of 6 types of resin, in order to prevent contamination of the drug solution. is also preferable. Examples of these containers include the containers described in JP-A No. 2015-123351.

The wetted parts of this container may be made of the corrosion-resistant material described above (preferably electropolished stainless steel or fluororesin) or glass. In order to obtain better effects of the present invention, it is preferable that 90% or more of the area of the liquid contacting part be made of the above material, and it is more preferable that the entire liquid contact part be made of the above material.

The porosity in 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.
Note that the porosity is calculated according to equation (1).
Formula (1): Porosity = {1-(volume of chemical solution in container/container volume of container)}×100
The container volume has the same meaning as the internal volume (capacity) of the container.
By setting the porosity within this range, storage stability can be ensured by limiting contamination such as impurities.

The present invention will be explained in more detail below based on Examples. The materials, amounts used, proportions, processing details, processing procedures, etc. 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 construed as being limited by the Examples shown below.

Further, in preparing the chemical solutions of Examples and Comparative Examples, handling of containers, preparation of chemical solutions, filling, storage, and analysis measurements were all performed in a clean room meeting ISO class 2 or 1.

(filter)
The following filters were used.
・“Purasol SN 200nm”: UPE membrane (material) manufactured by Entegris, pore size 200nm
・"PP 200nm": Polypropylene filter, manufactured by Entegris, pore size 200nm
・“Purasol SP 200nm”: UPE membrane (material) manufactured by Entegris, pore size 200nm
・"Octolex 5nm": Nylon filter graft made by UPE, made by Entegris, pore size 5nm
・"IEX 15nm": Ion exchange resin filter, manufactured by Entegris, pore size 15nm
・"IEX 16nm": Ion exchange resin filter, manufactured by Entegris, pore size 16nm
・"IEX 50nm": Ion exchange resin filter, manufactured by Entegris, pore size 50nm
・"IEX 200nm": Ion exchange resin filter, manufactured by Entegris, pore size 200nm
・"PTFE 5nm": Polytetrafluoroethylene filter, manufactured by Entegris, pore size 5nm
・"PTFE 7nm": Polytetrafluoroethylene filter, manufactured by Entegris, pore size 7nm
・"PTFE 10nm": Polytetrafluoroethylene filter, manufactured by Entegris, pore size 10nm
・"PTFE 20nm": Polytetrafluoroethylene filter, manufactured by Entegris, pore size 20nm
・"Nylon 5nm": Nylon filter, manufactured by Pall, pore size 5nm
・"UPE 1nm": Ultra-high molecular weight polyethylene filter, manufactured by Pall, pore size 1nm
・“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>
For producing the chemical solutions of Examples and Comparative Examples, the following organic solvents were used as substances 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, for "Raw material 1" to "Raw material 8" in the table, the organic solvents used in each example and comparative example were purchased from the following manufacturers. express something.
"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 chemical solution.
・EP-SUS: Container whose wetted part is electropolished stainless steel ・PFA: Container whose wetted part is coated with perfluoroalkoxyalkane The filling rate of the chemical solution in each container is 95% by volume ( The porosity was 5% by volume).
The filling rate is determined by the following formula.
Filling rate = (volume of drug solution in container/volume of container) x 100

<Purification procedure>
One type selected from the above-mentioned products to be purified was subjected to the distillation purification treatment described in Table 1.
In addition, "Yes-1" in the "Distillation purification" column in the table indicates that vacuum distillation was performed using a distillation column (theoretical plate number: 15), and "Yes-2" indicates that the distillation column (theoretical plate number: 15) was carried out. 30 plates) represents that vacuum distillation was carried out twice, and "Y-3" indicates that vacuum distillation was carried out using a distillation column (theoretical plate number: 8 plates).

Next, the purified product by distillation is stored in a storage tank, and the purified product stored in the storage tank is passed through filters 1 to 5 listed in Table 1 in this order to be filtered and stored. stored in a tank.
Next, the material to be purified stored in the storage tank is filtered through filters 6 to 7 listed in Table 1, and the material to be purified after filtering through filter 7 is circulated to the upstream side of filter 6 and filtered again. Circulating filtration treatment was carried out by filtering at 6 to 7 filters.
After the circulation filtration process, the chemical solution was placed in the container.
Note that in Examples 85 to 88, water was added to the chemical solution so that the water content became a predetermined value.

In addition, in the series of purification processes described above, the liquid-contact parts of various devices (for example, distillation columns, piping, storage tanks, etc.) with which the product to be purified comes into contact are made of electrolytically polished stainless steel.

The content of organic components and metal components in the chemical solution was measured by the method shown below.

<Content of metal components>
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 for the analysis.
- Syngistix nano application module dedicated to "SP-ICP-MS" - Syngistix for ICP-MS software However, since metal-containing particles of 10 nm or less cannot be measured with SP-ICP-MS, the above-mentioned identification method was used.

<Content of organic impurities>
The content of organic impurities in various 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 liquid or rinse liquid]
The defect suppression ability of the produced chemical solution when used as a pre-wetting solution or a rinsing solution was evaluated by the method shown below.
First, a chemical solution is spin-discharged onto a silicon substrate with a diameter of 300 mm or a silicon substrate with a silicon oxide film (a silicon substrate whose surface is covered with a silicon oxide film) with a diameter of 300 mm, and while rotating the substrate, it is applied to the surface of the substrate. Then, 0.5 cc of each chemical solution was discharged. The substrate was then spun dry. Next, using a wafer inspection device "SP-5" manufactured by KLA-Tencor, the number of defects present on the substrate after the chemical solution was applied was measured (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 spot-like residue defects. A metal residue defect is a residue derived from a metal component, a composite residue defect is a residue derived from a composite of an organic substance and a metal component, and a stain-like residue defect is a residue derived from an organic substance.
In addition, if both "metal residue on Si" and "metal residue on _SiO2 " are "D" or more, it is suitably used as a pre-wetting liquid or a rinsing liquid.

<Individual evaluation (metal residue defect, composite residue defect, stain-like residue defect)>
A: The number of corresponding defects was 20 or less per board.
B: The number of corresponding defects was more than 20/substrate and less than 50/substrate.
C: The number of corresponding defects was more than 50/substrate and less than 100/substrate.
D: The number of corresponding defects was more than 100/substrate and less than 150/substrate.
E: The number of corresponding defects exceeded 150/substrate.

[Developer]
The produced chemical solution was evaluated when used as a developer by the method shown below.
First, a resist pattern was formed by the following operations.
The actinic ray-sensitive or radiation-sensitive resin composition described below is applied to a silicon substrate with a diameter of 300 mm or a silicon substrate with a silicon oxide film with a diameter of 300 mm, and prebaked (PB) is performed at 100 ° C. for 60 seconds. , a resist film with a thickness of 150 nm was formed.

(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 value written in each repeating unit means mol%): 100 parts by mass

Photoacid generator shown below: 8 parts by mass

Quencher shown below: 5 parts by mass (mass ratio was 0.1:0.3:0.3:0.2 from left to right). Note that among the quenchers listed below, the polymer type quencher has a weight average molecular weight (Mw) of 5,000. Moreover, the numerical value described in each repeating unit means a molar ratio.

Hydrophobic resin shown below: 4 parts by mass (mass ratio was 0.5:0.5 from left to right.) Among the hydrophobic resins shown below, the hydrophobic resin on the left has a weight average molecular weight. (Mw) is 7,000, and the weight average molecular weight (Mw) of the hydrophobic resin on the right is 8,000. In addition, in each hydrophobic resin, the numerical value described in each repeating unit means a 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/cm ² using an ArF excimer laser scanner (Numerical Aperture: 0.75). Thereafter, it was heated at 120°C for 60 seconds. Next, each developing solution (chemical solution) was paddled for 30 seconds for development. Next, the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds to form a negative resist pattern. Thereafter, the obtained negative resist pattern was heated at 200° C. for 300 seconds. Through the above steps, an L/S pattern (average pattern width: 45 nm) with a line/space ratio of 1:1 was obtained.
In the space portion of the obtained sample, the presence or absence of the above-mentioned metal residue defect, composite residue defect, and spot-like residue defect was evaluated according to the above method.

In addition, in each Example, the difference in pressure between each filter was 0.01 to 0.03 MPa.
In Table 1, "Application 1" in the "Application" column means that the above test was conducted using the chemical solution described in each Example and Comparative Example as a pre-wetting solution and a rinsing solution. "Application 2" in the "Application" column means that the above test was conducted using the chemical solution described in each Example and Comparative Example as a developer.
In the table, "Metal residue on Si" indicates the evaluation result of metal residue defects on silicon substrate, and "Composite residue on Si" indicates the evaluation result of compound residue defect on silicon substrate. "Spot-like residue on Si" shows the evaluation results for spot-like residue defects on silicon substrate, and "Metal residue on SiO ₂ " shows the evaluation results for spot-like residue defects on silicon substrate with silicon oxide film. "Composite residue on _SiO2 " shows the evaluation results of composite residue defects on a silicon substrate with a silicon oxide film.

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

In Table 1, the data related to each example and comparative example are Table 1 [Part 1] <1> to <6>, Table 1 [Part 2] <1> to <6>, Table 1 [Part 3] <1> to <6> and each row of 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, and as shown in Table 1 [Part 1] <2>, the filter 2 was '', as shown in Table 1 [Part 1] <3>, the Ti oxide particles/Ti ions in the chemical solution are 3.5E+04, and as shown in Table 1 [Part 1] <4>, the Al ions The amount is 32 mass ppt, and as shown in Table 1 [Part 1] <5>, the proportion of 0.5-17 nm oxidized Fe particles is 81% by mass, and as shown in Table 1 [Part 1] <6>. As shown, "metal residue on Si" is "A". The same applies to other Examples and Comparative Examples.

From the results shown in the table, it was confirmed that the chemical solution of the present invention can achieve the desired effects.
In particular, by comparing Examples 1 to 8, it was confirmed that the effect is more excellent when the mass ratio of the content of titanium oxide particles to the content of titanium ions is 10 ¹ to 10 ¹⁰ .
Furthermore, from Examples 9 and 10, it was confirmed that the effect was more excellent when the mass ratio of the content of iron oxide particles to the content of iron ions was 10 ⁰ to 10 ¹² .
Further, from Examples 11 and 12, it was confirmed that the effect is more excellent when the mass ratio of the content of aluminum oxide particles to the content of aluminum ions is 10 ⁰ to 10 ¹² .
Further, from Examples 13 and 14 (34 and 35, 55 and 56, 76 and 77), the content of titanium ions (or iron ions, aluminum ions) was 0.10 to 100% based on the total mass of the chemical solution. It was confirmed that the effect is more excellent when the mass is ppt.
Furthermore, from Examples 16 and 17 (37 and 38, 58 and 59, 79 and 80), the content of titanium oxide particles (or iron oxide particles, aluminum oxide particles) is the same as the content of titanium component in the metal component. It was confirmed that the effect is more excellent when the content is 5% by mass or more and less than 99% by mass.
In addition, from Examples 18 and 19 (39 and 40, 60 and 61, 81 and 82), it was found that among titanium oxide particles (or iron oxide particles, aluminum oxide particles), particles with a particle size of 0.5 to 17 nm It was confirmed that the effect is more excellent when the ratio is 60% by mass or more and less than 98% by mass.
Further, from Examples 20 and 21 (41 and 42, 62 and 63, 83 and 84), the effect is more excellent when the content of organic impurities is 1000 to 100000 ppt by mass based on the total mass of the chemical solution. was confirmed.

After cleaning the container (EP-SUS) and various devices used in the <purification procedure> using the chemical solution (100 L) of Example 22, the separately prepared chemical solution of Example 22 was poured into the cleaned device. The solution was collected in a washed container to obtain solution A in the container.
In addition, after cleaning the container (EP-SUS) and various devices used in the <purification procedure> using the chemical solution (100 L) of Example 38, the separately prepared chemical solution of Example 22 was poured into the cleaned device. The solution was collected in a washed container to obtain solution B in the container.
When evaluating "metal residue defects on Si" using solution A and solution B, better results were obtained with solution A.

<Example (EUV exposure)>
First, resist composition 1 was obtained by mixing each component in the following composition.
・Resin (A-1): 0.77g
・Photoacid generator (B-1): 0.03g
・Basic compound (E-3): 0.03g
・PGMEA (commercial product, high purity grade): 67.5g
・Ethyl lactate (commercial product, high purity grade): 75g

・Resin (A-1)
The following resin was used as the resin (A-1).

・Photoacid generator (B-1)
The following compound was used as the photoacid generator (B-1).

・Basic compound (E-3)
The following compound was used as the basic compound (E-3).

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

This resist film was exposed to light 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). Thereafter, it was heated (PEB: Post Exposure Bake) at 85° C. for 60 seconds. Next, a developing solution (butyl acetate/manufactured by FETW) was sprayed for 30 seconds using a spray method for development, and a rinsing solution was sprayed onto the silicon wafer for 20 seconds using a spin coating method to rinse the silicon wafer. Subsequently, 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.
As the rinsing liquid, the chemical solution used in Example 44 described above was used. In addition, when the above-mentioned various evaluations were carried out, the desired effects with the same tendency as in Table 1 were obtained.

Claims (22)

A chemical solution containing an organic solvent and a metal component,
The metal component contains titanium oxide particles and titanium ions,
A chemical solution, wherein the 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 mass ppt with respect to the total mass of the chemical solution,
A chemical solution used in pre-wet solution, developer solution, or rinse solution. The chemical solution according to claim 1, wherein the content of the titanium oxide particles is 5% by mass or more and less than 99% by mass with respect to the content of the titanium component in the metal component. The chemical solution 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,
The chemical liquid according to any one of claims 1 to 3, wherein the iron ion content is 0.10 to 100 mass ppt based on the total mass of the chemical liquid. the metal component contains iron oxide particles,
The chemical solution according to any one of claims 1 to 4, 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 contains iron oxide particles,
The chemical solution according to any one of claims 1 to 5, wherein the proportion of particles having a particle size of 0.5 to 17 nm among 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,
The chemical solution according to any one of claims 1 to 6, 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 . the metal component contains aluminum ions,
The chemical solution according to any one of claims 1 to 7, wherein the content of the aluminum ion is 0.10 to 100 mass ppt based on the total mass of the chemical solution. The metal component contains aluminum oxide particles,
The chemical solution according to any one of claims 1 to 8, 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 the proportion of particles having a particle size of 0.5 to 17 nm among the aluminum oxide particles is 60% by mass or more and less than 98% by mass. The metal component contains aluminum oxide particles and aluminum ions,
The chemical solution according to any one of claims 1 to 10, wherein the mass ratio of the content of the aluminum oxide particles to the content of the aluminum ions is 10 ⁰ to 10 ¹² . The metal component contains copper oxide particles,
The chemical solution according to any one of claims 1 to 11, 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. The metal component contains copper oxide particles,
The chemical solution according to any one of claims 1 to 12, wherein the proportion of particles having a particle size of 0.5 to 17 nm among the copper oxide particles is 60% by mass or more and less than 98% by mass. The metal component contains copper oxide particles and copper ions,
The chemical solution according to any one of claims 1 to 13, wherein the mass ratio of the content of the copper oxide particles to the content of the copper ions is 10 ⁰ to 10 ¹² . 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 oxide ions,
The mass ratio of the content of the titanium oxide particles to the content of the titanium ions is 10 ⁰ ~10 ⁷ A medicinal liquid,
The content of the titanium ions is 0.10 to 100 mass ppt with respect to the total mass of the chemical solution,
The content of the iron ions is 0.10 to 100 mass ppt with respect 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 based on 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,
The mass ratio of the content of the copper oxide particles to the content of the copper ions is 10 ⁰ ~10 ¹² and
A chemical solution used in pre-wet solution, developer solution, or rinse solution. Furthermore, it contains organic impurities,
The chemical solution according to any one of claims 1 to 15 , wherein the content of the organic impurity is 1,000 to 100,000 ppt by mass based on the total mass of the chemical solution. The chemical solution according to any one of claims 1 to 16 , wherein the content of water based on the total mass of the chemical solution is 500 mass ppb or less. The organic solvent is 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 - The drug solution according to any one of claims 1 to 17 , comprising one or more selected from the group consisting of heptanone, butyl butyrate, isobutyl isobutyrate, isoamyl ether, and undecane. the organic solvent is butyl acetate,
The chemical solution according to any one of claims 1 to 18 , which is used in a developer. 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,
The mass ratio of the content of the titanium oxide particles to the content of the titanium ions is 10 ⁰ ~10 ⁷ A medicinal liquid,
The content of the titanium ions is 0.10 to 100 mass ppt with respect to the total mass of the chemical solution,
A chemical solution used in developer. The organic solvent is propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, cyclohexanone, ethyl lactate, propylene carbonate, isopropanol, 4-methyl-2-pentanol, propylene glycol monopropyl ether, methyl methoxyprokionate, 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, isobutyric acid Contains one or more selected from the group consisting of isobutyl, isoamyl ether, and undecane,
The chemical solution according to any one of claims 1 to 18, which is used as a pre-wetting solution or a rinsing solution. A drug solution container comprising a container and the drug solution according to any one of claims 1 to 21 accommodated in the container.