Chemical solution and method for manufacturing chemical solution

Abstract

An object of the present invention is to provide a chemical solution that has excellent defect suppression performance even when applied to a resist process using EUV exposure, and also to provide a method for producing the chemical solution. The chemical solution of the present invention contains an organic solvent and metal-containing particles containing metal atoms, and the metal-containing particles are metal nanoparticles with a particle diameter of 0.5 to 17 nm, and the number of particles contained per unit volume of the chemical solution is 1.0 × 10 1 ~1.0×10 9 pieces / cm 3 is.

Description

[Technical Field]

[0001] The present invention relates to a chemical solution and a method for producing the chemical solution. [Background technology]

[0002] During the manufacture of semiconductor devices through wiring formation processes including photolithography, chemical solutions containing water and / or organic solvents are used as pre-wet solutions, resist solutions (resist compositions), developers, rinse solutions, stripping solutions, chemical mechanical polishing (CMP) slurries, and post-CMP cleaning solutions, or as dilutions thereof. In recent years, advances in photolithography technology have led to advances in pattern miniaturization. One method for achieving this is to shorten the wavelength of the exposure light source, and attempts are being made to form patterns using even shorter wavelength light such as extreme ultraviolet (EUV) as the exposure light source, instead of conventionally used ultraviolet light, KrF excimer lasers, and ArF excimer lasers. The development of pattern formation using EUV or the like is progressing with a target resist pattern width of 10 to 15 nm, and the chemicals used in this process are being required to have even greater defect suppression performance.

[0003] As a method for producing a chemical solution used in conventional resist pattern formation, Patent Document 1 states, "A method for producing a resist composition used in a semiconductor device manufacturing process, in which a manufacturing device for the resist composition is washed with a cleaning solution, the cleaning solution is removed from the manufacturing device and spin-coated onto an evaluation substrate, and the change in defect density of defects of 100 nm or larger before and after coating on the evaluation substrate is 0.2 defects / cm. 2 and then producing a resist composition in a manufacturing apparatus." The document also describes that when a chemical solution (resist composition) produced by this method was used for ArF exposure, pattern defects and the like were suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-049395 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have found that when a pattern is formed by EUV exposure using a resist composition containing a chemical solution produced by the above-described production method, defects occur. Therefore, an object of the present invention is to provide a chemical solution that is less likely to cause defects when applied to a resist process using EUV exposure, in other words, that has excellent defect suppression performance when applied to a resist process using EUV exposure. Another object of the present invention is to provide a method for producing a chemical solution. [Means for solving the problem]

[0006] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[0007] [1] A chemical solution containing an organic solvent and metal-containing particles containing metal atoms, wherein the metal-containing particles are metal nanoparticles having a particle diameter of 0.5 to 17 nm, and the number of particles contained per unit volume of the chemical solution is 1.0 × 10 1 ~1.0×10 9 pieces / cm 3 That is, a chemical solution. [2] The chemical solution according to [1], wherein the particle size distribution based on the number of metal-containing particles has a maximum value in at least one range selected from the group consisting of a range of particle diameters less than 5 nm and a range of particle diameters greater than 17 nm. [3] The drug solution according to [2], wherein the particle size distribution has a maximum value in the range of particle sizes of 0.5 nm or more and less than 5 nm. [4] The chemical solution according to any one of [1] to [3], which is used in the manufacture of a semiconductor device. [5] The chemical solution according to any one of [1] to [4], wherein the metal nanoparticles are at least one selected from the group consisting of particles A consisting of simple metal atoms, particles B consisting of oxides of metal atoms, and particles C consisting of simple metal atoms and oxides of metal atoms. [6] The drug solution according to [5], wherein the ratio of the number of particles A contained to the sum of the number of particles B contained and the number of particles C contained per unit volume of the drug solution is less than 1.0. [7] The particle number ratio is 1.0×10 -1 The drug solution according to [5] or [6], which is as follows: [8] The chemical solution according to any one of [1] to [7], further containing an organic compound having a boiling point of 300°C or higher. [9] The chemical solution according to [8], wherein at least a portion of the metal nanoparticles are particles U containing an organic compound.

[10] At least a portion of the metal nanoparticles are particles U containing an organic compound and particles V containing no organic compound, and the ratio of the number of particles U to the number of particles V per unit volume of the chemical solution is 1.0 × 10 1 The drug solution according to [8] or [9] above.

[11] The chemical solution according to any one of [1] to

[10] , wherein the metal nanoparticles contain at least one type selected from the group consisting of metal nanoparticles containing Pb atoms and metal nanoparticles containing Ti atoms.

[12] The chemical solution according to any one of [1] to

[11] , wherein the metal nanoparticles contain metal nanoparticles containing Pb atoms and metal nanoparticles containing Ti atoms.

[13] The ratio of the number of metal nanoparticles containing Pb atoms to the number of metal nanoparticles containing Ti atoms per unit volume of the chemical solution is 1.0 × 10 -3 The drug solution according to any one of [1] to

[12] , wherein the value of the drug solution is 0.0 to 2.0.

[14] A method for producing the chemical solution according to any one of [1] to

[13] , comprising a filtration step of filtering a material to be purified containing an organic solvent using a filter to obtain the chemical solution.

[15] The method for producing a drug solution according to

[14] , wherein the filtration step is a multistage filtration step in which the material to be purified is passed through two or more types of filters that differ in at least one property selected from the group consisting of filter material, pore size, and pore structure.

[16] A method for producing a drug solution according to

[14] or

[15] , wherein, when one filter is used, the pore diameter of the filter is 5 nm or less, and when two or more filters are used, the pore diameter of the filter with the smallest pore diameter among the filters is 5 nm or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a chemical solution that has excellent defect suppression performance even when applied to a resist process using EUV exposure. Also, the present invention can provide a method for producing the chemical solution. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a typical example of a purification apparatus capable of carrying out a multistage filtration process. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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 the present invention, "ppm" stands for "parts-per-million (10 -6 ) and "ppb" stands for "parts-per-billion (10 -9 ) and "ppt" stands for "parts-per-trillion (10 -12 ) and "ppq" stands for "parts-per-quadrillion (10 -15 )" Furthermore, in the description of groups (atomic groups) in the present invention, when a notation does not specify whether they are substituted or unsubstituted, it encompasses both those that have no substituents and those that have substituents, as long as it does not impair the effects of the present invention. For example, the term "hydrocarbon group" encompasses not only hydrocarbon groups that have no substituents (unsubstituted hydrocarbon groups) but also hydrocarbon groups that have substituents (substituted hydrocarbon groups). This also applies to each compound. In the present invention, "radiation" refers to, for example, far ultraviolet, extreme ultraviolet (EUV), X-rays, or electron beams. In the present invention, "light" refers to actinic rays or radiation. Unless otherwise specified, "exposure" in the present invention includes not only exposure with far ultraviolet, X-rays, EUV, or the like, but also writing with particle beams such as electron beams or ion beams.

[0011] [Chemical solution] The chemical solution according to an embodiment of the present invention (hereinafter also referred to as "the chemical solution") is a chemical solution containing an organic solvent and metal-containing particles containing metal atoms, and the number of metal nanoparticles having a particle diameter of 0.5 to 17 nm contained in the chemical solution is 1.0 × 10 1 ~1.0×10 9 pieces / cm 3 It is a medicinal solution. Although the mechanism by which the present pharmaceutical solution solves the above problems is not entirely clear, the present inventors speculate that the mechanism is as follows: Note that the following mechanism is speculated, and even if the effects of the present invention are achieved by a different mechanism, it is still within the scope of the present invention.

[0012] This chemical solution contains metal nanoparticles with a particle size of 0.5 to 17 nm, and the number of particles contained in the chemical solution is 1.0 × 10 1 ~1.0×10 9 pieces / cm 3 One of the features is that it is controlled to In processes that use EUV exposure, there is a need to narrow the resist pattern spacing, pattern width, and pattern pitch, which is the sum of the width of a single periodically arranged pattern and the spacing between the patterns, as well as the spacing of the manufactured wiring, wiring width, and the wiring pitch, which is the sum of the width of a single periodically arranged wiring and the spacing between the wirings. Specifically, the pattern width and / or pattern spacing is often about 10 to 15 nm (in this case, the pattern pitch is often 20 to 30 nm). In such cases, the present inventors have found that it is necessary to control finer particles in units of their number, which has not been a major problem in conventional processes.

[0013] Among the above particles, metal-containing particles with a particle size of less than 0.5 nm tend to aggregate more easily, resulting in the formation of coarse particles. Therefore, they are often removed during the process (for example, by being washed away), and it is presumed that they do not have a significant impact on the defect suppression performance of the chemical solution. On the other hand, among the above particles, metal-containing particles with a particle diameter of more than 17 nm are sufficiently large compared to the required resist pitch, and therefore, as mentioned above, are likely to be removed during the process, and it is presumed that their impact on the defect suppression performance of the chemical solution is not significant.

[0014] It is estimated that metal nanoparticles with a particle diameter of 0.5 to 17 nm tend to be more difficult to remove from the substrate. 1 pieces / cm 3 If the above conditions are met, the metal nanoparticles are more likely to aggregate and are more likely to be removed during the process, and as a result, it is presumed that the chemical solution has excellent defect suppression performance. On the other hand, when the number of metal nanoparticles contained per unit volume of the chemical solution is 1.0 × 10 9 pieces / cm 3 It is presumed that if the content is below this level, the metal nanoparticles themselves are prevented from becoming the cause of defects, and as a result the chemical solution has excellent defect suppression performance. The content of metal nanoparticles in the chemical solution can be measured by the method described in the Examples, and the number of particles (number) per unit volume of the chemical solution of metal nanoparticles is calculated by rounding to two significant digits.

[0015] [Organic solvent] The chemical solution contains an organic solvent. The content of the organic solvent in the chemical solution is not particularly limited, but is generally preferably 98.0% by mass or more, more preferably 99.0% by mass or more, even more preferably 99.9% by mass or more, and particularly preferably 99.99% by mass or more, based on the total mass of the chemical solution. The upper limit is not particularly limited, but is often 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 in combination, the total content is preferably within the above range.

[0016] 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 is considered to be an organic solvent. In this specification, the term "liquid" means that the substance is liquid at 25°C and atmospheric pressure.

[0017] The type of the organic solvent is not particularly limited, and known organic solvents can be used. Examples of the organic solvent 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, and alkyl pyruvates. Furthermore, as the organic solvent, for example, those described in JP-A-2016-057614, JP-A-2014-219664, JP-A-2016-138219, and JP-A-2015-135379 may be used.

[0018] The organic solvent is preferably at least one selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monoethyl ether (PGME), propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl methoxypropionate, cyclopentanone, cyclohexanone (CHN), γ-butyrolactone, diisoamyl ether, butyl acetate (nBA), isoamyl acetate, isopropanol, 4-methyl-2-pentanol, dimethyl sulfoxide, n-methyl-2-pyrrolidone, diethylene glycol, ethylene glycol, dipropylene glycol, propylene glycol, ethylene carbonate, propylene carbonate (PC), sulfolane, cycloheptanone, 1-hexanol, decane, and 2-heptanone. Among these, CHN, PGMEA, PGME, nBA, PC, and mixtures thereof are preferred because they provide a chemical solution that exhibits the effects of the present invention more effectively. The organic solvents may be used alone or in combination of two or more. The type and content of the organic solvent in the chemical solution can be measured using a gas chromatograph mass spectrometer.

[0019] [Metal-containing particles] The chemical solution contains metal-containing particles that contain metal atoms. Although a preferred embodiment of the method for producing the present chemical solution will be described later, the present chemical solution can generally be produced by purifying a material to be purified that contains the organic solvent and impurities as already described. The metal-containing particles may be intentionally added during the production process of the chemical solution, may be originally contained in the material to be purified, or may be transferred (so-called contamination) from a chemical solution production device or the like during the production process of the chemical solution.

[0020] The metal atoms are not particularly limited, but examples thereof include Fe atoms, Al atoms, Cr atoms, Ni atoms, Pb atoms, Zn atoms, and Ti atoms. Among these, by strictly controlling the content of metal-containing particles containing at least one selected from the group consisting of Fe atoms, Al atoms, Pb atoms, Zn atoms, and Ti atoms in the chemical solution, better defect suppression performance is likely to be obtained, and by strictly controlling the content of metal-containing particles containing at least one selected from the group consisting of Pb atoms and Ti atoms in the chemical solution, even better defect suppression performance is likely to be obtained. That is, the metal atom is preferably at least one selected from the group consisting of Fe atoms, Al atoms, Cr atoms, Ni atoms, Pb atoms, Zn atoms, and Ti atoms, more preferably at least one selected from the group consisting of Fe atoms, Al atoms, Pb atoms, Zn atoms, and Ti atoms, and even more preferably at least one selected from the group consisting of Pb atoms and Ti atoms, and it is particularly preferable that the metal-containing particle contains both Pb atoms and Ti atoms. The metal-containing particles may contain one type of the above metal atom alone or two or more types in combination.

[0021] The particle diameter of the metal-containing particles is not particularly limited, but for example, in chemical solutions used to manufacture semiconductor devices, the content of particles having a particle diameter of about 0.1 to 100 nm in the chemical solution is often subject to control. In particular, according to the research of the present inventors, it has been found that, in particular, in a chemical solution used in an EUV exposure photoresist process, a chemical solution having excellent defect suppression performance can be easily obtained by controlling the content of metal-containing particles (hereinafter also referred to as "metal nanoparticles") having a particle diameter of 0.5 to 17 nm in the chemical solution. As already explained, in an EUV exposure photoresist process, fine resist spacing, resist width, and resist pitch are often required. In such cases, it is required to control the number of finer particles, which has not been a major problem in conventional processes.

[0022] The particle size distribution based on the number of metal-containing particles is not particularly limited, but it is preferable that the particle size distribution has a maximum value in at least one selected from the group consisting of a particle size range of less than 5 nm and a particle size range of more than 17 nm, in order to obtain a chemical solution having better effects of the present invention. In other words, it is preferable that the particle diameter does not have a maximum value in the range of 5 to 17 nm. By not having a maximum value in the range of 5 to 17 nm, the chemical solution has better defect suppression performance, particularly better bridge defect suppression performance. Bridge defect suppression performance refers to defects evaluated by the method described in the examples. Furthermore, in order to obtain a chemical solution having even better effects of the present invention, it is more preferable that the particle size distribution based on number has a maximum value in the particle size range of 0.5 nm or more and less than 5 nm. As a result, the chemical solution has even better ability to suppress bridge defects.

[0023] <Metal nanoparticles> Metal nanoparticles refer to metal-containing particles with a particle diameter of 0.5 to 17 nm. The number of metal nanoparticles contained per unit volume of the chemical solution is 1.0 x 10 1 ~1.0×10 9 pieces / cm 3 The number of particles contained in this solution is 1.0 × 10 2 pieces / cm 3 More than 1.0×10 is preferable. 3 pieces / cm 3 More preferably, 1.0×10 6 pieces / cm 3 Less than 1.0 x 10 is preferable. 5 pieces / cm 3 The following is preferable: 1.x10 4 pieces / cm 3 The following is even more preferred: The number of metal nanoparticles contained per unit volume of the chemical solution is 1.0 x 10 2 ~1.0×10 6 pieces / cm 3 In this case, the chemical solution has better defect suppression performance.

[0024] The metal atoms contained in the metal nanoparticles are not particularly limited, but are the same as the atoms already described as the metal atoms contained in the metal-containing particles. Among these, in order to obtain a chemical solution having a more excellent effect of the present invention, the metal atoms are preferably at least one selected from the group consisting of Pb atoms and Ti atoms, and it is more preferable that the metal nanoparticles contain both Pb atoms and Ti atoms. In other words, it is preferable that the metal nanoparticles contain at least one selected from the group consisting of metal nanoparticles containing Pb atoms (hereinafter also referred to as "Pb nanoparticles") and metal nanoparticles containing Ti atoms (hereinafter also referred to as "Ti nanoparticles"), and it is more preferable that they contain both Pb nanoparticles and Ti nanoparticles. The metal nanoparticles containing both Pb atoms and Ti atoms typically refer to a form in which the chemical solution contains both metal nanoparticles containing Pb atoms and metal nanoparticles containing Ti atoms.

[0025] The particle number ratio (Pb / Ti) of Pb nanoparticles and Ti nanoparticles contained in the chemical solution is not particularly limited, but is generally 1.0 × 10 -4 ~3.0 is preferred, 1.0 × 10 -3 ~2.0 is more preferable, and 1.0 × 10 -2 Pb / Ti is more preferably 1.0×10 to 1.5. -3 When the viscosity is 2.0 or less, the chemical solution has a better effect of the present invention, in particular, a better ability to suppress bridge defects. The present inventors have found that Pb nanoparticles and Ti nanoparticles are likely to associate with each other, for example, when a chemical solution is applied to a wafer, and this is likely to cause defects (particularly bridge defects) during development of a resist film. Pb / Ti is 1.0×10 -3 Surprisingly, when the ratio is 0.01 to 2.0, the occurrence of defects is more easily suppressed. In this specification, Pb / Ti, A / (B+C) described later, and U / V described later are calculated by rounding off to two significant digits.

[0026] Metal nanoparticles may contain metal atoms, and their form is not particularly limited. Examples include simple metal atoms, compounds containing metal atoms (hereinafter also referred to as "metal compounds"), and composites thereof. Metal nanoparticles may also contain multiple metal atoms. When metal nanoparticles contain multiple metals, the metal atom with the highest content (atm%) of the multiple metals is the main component. Therefore, when Pb nanoparticles are used, it means that when multiple metals are contained, Pb atoms are the main component of the multiple metals.

[0027] The composite is not particularly limited, but examples thereof include so-called core-shell type particles having a simple metal atom and a metal compound that covers at least a part of the simple metal atom, solid solution particles containing a metal atom and other atoms, eutectic particles containing a metal atom and other atoms, aggregate particles of a simple metal atom and a metal compound, aggregate particles of different types of metal compounds, and metal compounds whose composition changes continuously or intermittently from the particle surface toward the center.

[0028] The atoms other than the metal atom contained in the metal compound are not particularly limited, but examples thereof include carbon atoms, oxygen atoms, nitrogen atoms, hydrogen atoms, sulfur atoms, and phosphorus atoms, among which oxygen atoms are preferred. The form in which the metal compound contains oxygen atoms is not particularly limited, but an oxide of the metal atom is more preferred.

[0029] In order to obtain a chemical solution having a more excellent effect of the present invention, it is preferable that the metal nanoparticles consist of at least one type selected from the group consisting of particles consisting of simple metal atoms (particles A), particles consisting of oxides of metal atoms (particles B), and particles consisting of simple metal atoms and oxides of metal atoms (particles C). The relationship between the number of particles A, the number of particles B, and the number of particles C in the number of metal nanoparticles contained per unit volume of the chemical solution is not particularly limited. However, in order to obtain a chemical solution having a more excellent effect of the present invention, the ratio of the number of particles A to the total number of particles B and the number of particles C (hereinafter also referred to as "A / (B+C)") is preferably 1.5 or less, more preferably less than 1.0, and more preferably 2.0 × 10 -1 More preferably, 1.0 x 10 -1 The following is particularly preferred: 1.0 x 10 -3 More than 1.0×10 is preferable. -2 The above is more preferable. When A / (B+C) is less than 1.0, the chemical solution has better bridge defect suppression performance, better pattern width uniformity performance, and better stain defect suppression performance. Also, A / (B+C) is 0.1 (1.0 × 10 -1 ) or less, the chemical solution has better residue defect suppression performance.

[0030] [Other ingredients] The chemical solution may contain other components in addition to those mentioned above, such as organic compounds other than organic solvents (particularly organic compounds with a boiling point of 300° C. or higher), water, and resins.

[0031] <Organic compounds other than organic solvents> The chemical solution may contain an organic compound other than an organic solvent (hereinafter also referred to as a "specific organic compound"). In this specification, a specific organic compound means a compound that is different from the organic solvent contained in the chemical solution and that is contained in an amount of 10,000 ppm by mass or less relative to the total mass of the chemical solution. In other words, in this specification, an organic compound that is contained in an amount of 10,000 ppm by mass or less relative to the total mass of the chemical solution is considered to be a specific organic compound, but not an organic solvent. In addition, when multiple types of organic compounds are contained in a chemical solution and each organic compound is contained in an amount of 10,000 mass ppm or less as described above, each of the organic compounds falls under the category of a specific organic compound.

[0032] The specific organic compound may be added to the chemical solution, or may be unintentionally mixed in during the manufacturing process of the chemical solution. Examples of cases where the specific organic compound is unintentionally mixed in during the manufacturing process of the chemical solution include, but are not limited to, when the specific organic compound is contained in a raw material (e.g., an organic solvent) used in manufacturing the chemical solution, or when the specific organic compound is mixed in during the manufacturing process of the chemical solution (e.g., contamination).

[0033] The content of the specific organic compound in the chemical solution can be measured using a GCMS (gas chromatography mass spectrometry).

[0034] The number of carbon atoms in the specific organic compound is not particularly limited, but in order for the chemical solution to have a better effect of the present invention, it is preferably 8 or more, more preferably 12 or more. The upper limit of the number of carbon atoms is not particularly limited, but it is preferably 30 or less.

[0035] The specific organic compound may be, for example, a by-product produced in the synthesis of an organic solvent and / or an unreacted raw material (hereinafter also referred to as "by-products, etc."). Examples of the by-products include compounds represented by the following formulae I to V.

[0036] [ka]

[0037] In Formula I, R1 and R2 each independently represent an alkyl group or a cycloalkyl group, or are bonded to each other to form a ring.

[0038] The alkyl group or cycloalkyl group represented by R1 and R2 is preferably an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 6 to 12 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 6 to 8 carbon atoms.

[0039] The ring formed by bonding R1 and R2 to each other is a lactone ring, preferably a 4- to 9-membered lactone ring, more preferably a 4- to 6-membered lactone ring.

[0040] It is preferable that R1 and R2 satisfy the relationship such that the compound represented by formula I has 8 or more carbon atoms.

[0041] In Formula II, R3 and R4 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, or a cycloalkenyl group, or are bonded to each other to form a ring, provided that R3 and R4 are not both hydrogen atoms.

[0042] The alkyl group represented by R3 and R4 is, for example, preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms.

[0043] The alkenyl group represented by R3 and R4 is, for example, preferably an alkenyl group having 2 to 12 carbon atoms, more preferably an alkenyl group having 2 to 8 carbon atoms.

[0044] The cycloalkyl group represented by R3 and R4 is preferably a cycloalkyl group having 6 to 12 carbon atoms, more preferably a cycloalkyl group having 6 to 8 carbon atoms.

[0045] The cycloalkenyl group represented by R3 and R4 is, for example, preferably a cycloalkenyl group having 3 to 12 carbon atoms, more preferably a cycloalkenyl group having 6 to 8 carbon atoms.

[0046] The ring formed by bonding R3 and R4 to each other is a cyclic ketone structure, which may be a saturated cyclic ketone or an unsaturated cyclic ketone. This cyclic ketone is preferably a 6- to 10-membered ring, more preferably a 6- to 8-membered ring.

[0047] It is preferable that R3 and R4 satisfy the relationship such that the number of carbon atoms in the compound represented by formula II is 8 or more.

[0048] In formula III, R5 represents an alkyl group or a cycloalkyl group.

[0049] The alkyl group represented by R5 is preferably an alkyl group having 6 or more carbon atoms, more preferably an alkyl group having 6 to 12 carbon atoms, and even more preferably an alkyl group having 6 to 10 carbon atoms. The alkyl group may have an ether bond in the chain, or may have a substituent such as a hydroxy group.

[0050] The cycloalkyl group represented by R5 is preferably a cycloalkyl group having 6 or more carbon atoms, more preferably a cycloalkyl group having 6 to 12 carbon atoms, and even more preferably a cycloalkyl group having 6 to 10 carbon atoms.

[0051] In formula IV, R6 and R7 each independently represent an alkyl group or a cycloalkyl group, or are bonded to each other to form a ring.

[0052] The alkyl group represented by R6 and R7 is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms.

[0053] The cycloalkyl group represented by R6 and R7 is preferably a cycloalkyl group having 6 to 12 carbon atoms, more preferably a cycloalkyl group having 6 to 8 carbon atoms.

[0054] The ring formed by R6 and R7 bonding to each other is a cyclic ether structure, which is preferably a 4- to 8-membered ring, and more preferably a 5- to 7-membered ring.

[0055] It is preferable that R6 and R7 satisfy the relationship such that the number of carbon atoms in the compound represented by formula IV is 8 or more.

[0056] In Formula V, R8 and R9 each independently represent an alkyl group or a cycloalkyl group, or are bonded to each other to form a ring, and L represents a single bond or an alkylene group.

[0057] The alkyl group represented by R8 and R9 is, for example, preferably an alkyl group having 6 to 12 carbon atoms, more preferably an alkyl group having 6 to 10 carbon atoms.

[0058] The cycloalkyl group represented by R8 and R9 is preferably a cycloalkyl group having 6 to 12 carbon atoms, more preferably a cycloalkyl group having 6 to 10 carbon atoms.

[0059] The ring formed by R8 and R9 bonding to each other is a cyclic diketone structure, which is preferably a 6- to 12-membered ring, and more preferably a 6- to 10-membered ring.

[0060] The alkylene group represented by L is, for example, preferably an alkylene group having 1 to 12 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms. R8, R9 and L satisfy the relationship that the compound represented by formula V has 8 or more carbon atoms. Although not particularly limited, when the organic solvent is an amide compound, an imide compound, or a sulfoxide compound, in one embodiment, examples thereof include amide compounds, imide compounds, and sulfoxide compounds having 6 or more carbon atoms. In addition, examples of the specific organic compound include the following compounds.

[0061] [ka]

[0062] [ka]

[0063] Examples of specific organic compounds include antioxidants such as dibutylhydroxytoluene (BHT), distearyl thiodipropionate (DSTP), 4,4'-butylidenebis-(6-t-butyl-3-methylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), and antioxidants described in JP 2015-200775 A; unreacted raw materials; structural isomers and by-products generated during the production of organic solvents; and leachates from components constituting organic solvent production equipment (for example, plasticizers leachate from rubber components such as O-rings).

[0064] In addition, specific organic compounds include dioctyl phthalate (DOP), bis(2-ethylhexyl) phthalate (DEHP), bis(2-propylheptyl) phthalate (DPHP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBzP), diisodecyl phthalate (DIDP), diisooctyl phthalate (DIOP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dihexyl phthalate, diisononyl phthalate (DINP), tris(2-ethylhexyl) trimellitate (TEHTM), tris(n-octyl-) trimellitate n-decyl) (ATM), bis(2-ethylhexyl) adipate (DEHA), monomethyl adipate (MMAD), dioctyl adipate (DOA), dibutyl sebacate (DBS), dibutyl maleate (DBM), diisobutyl maleate (DIBM), azelaic acid esters, benzoic acid esters, terephthalates (e.g., dioctyl terephthalate (DEHT)), 1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH), epoxidized vegetable oils, sulfonamides (e.g., N-(2-hydroxypropyl)benzenesulfonamide (HP BSA), N-(n-butyl)benzenesulfonamide (BBSA-NBBS)), organic phosphate esters (e.g., tricresyl phosphate (TCP), tributyl phosphate (TBP)), acetylated monoglycerides, triethyl citrate (TEC), acetyl triethyl citrate (ATEC), tributyl citrate (TBC), acetyl tributyl citrate (ATBC), trioctyl citrate (TOC), acetyl trioctyl citrate (ATOC), trihexyl citrate (THC), acetyl trihexyl citrate (ATHC), epoxidized soybean oil, ethylene propylene rubber, polybutene, addition polymers of 5-ethylidene-2-norbornene, and polymeric plasticizers exemplified below are also included. These specific organic compounds are presumed to be mixed into the product or chemical solution from filters, piping, tanks, O-rings, containers, etc. that come into contact with them during the purification process. In particular, compounds other than alkylolefins are associated with the occurrence of bridge defects.

[0065] [ka]

[0066] (organic compounds with a boiling point of 300°C or higher) The chemical solution may contain, among specific organic compounds, organic compounds with a boiling point of 300°C or higher (high-boiling organic compounds). When the chemical solution contains organic compounds with a boiling point of 300°C or higher, the boiling point is high and they are difficult to volatilize during the photolithography process. Therefore, in order to obtain a chemical solution with excellent defect suppression performance, it is necessary to strictly control the content and form of the high-boiling organic compounds in the chemical solution. Examples of such high-boiling organic compounds that have been confirmed include dioctyl phthalate (boiling point 385°C), diisononyl phthalate (boiling point 403°C), dioctyl adipate (boiling point 335°C), dibutyl phthalate (boiling point 340°C), and ethylene propylene rubber (boiling point 300 to 450°C).

[0067] The present inventors have found that when a high-boiling organic compound is contained in a chemical solution, it can take various forms. Examples of the form in which the high-boiling organic compound exists in the chemical solution include particles in which particles made of metal atoms or metal compounds and particles of the high-boiling organic compound are aggregated; particles having particles made of metal atoms or metal compounds and a high-boiling organic compound arranged so as to cover at least a portion of the particles; particles formed by coordinate bonding of metal atoms and a high-boiling organic compound; etc.

[0068] Among these, metal nanoparticles (particles U) containing an organic compound (preferably a high-boiling organic compound) are listed as a form that has a significant effect on the defect suppression performance of the chemical solution. The present inventors have found that by controlling the number of particles U contained per unit volume of the chemical solution, the defect suppression performance of the chemical solution can be dramatically improved. Although the reason for this is not entirely clear, particles U tend to have a relatively low surface free energy compared to metal nanoparticles (particles V) that do not contain an organic compound (preferably, a high-boiling organic compound). Such particles U are less likely to remain on a substrate treated with a chemical solution, and even if they do remain, they are more likely to be removed when the substrate comes into contact with the chemical solution again. For example, when a chemical solution is used as a developer and rinse, particles U are less likely to remain on the substrate during development and are more likely to be removed by rinsing, etc. In other words, as a result, both the organic compound (preferably, a high-boiling organic compound) and the particles containing metal atoms are more likely to be removed. Furthermore, since resist films are generally water-repellent, it is presumed that particles U, which have a lower surface energy, are less likely to remain on the substrate.

[0069] The ratio of the number of particles U to the number of particles V per unit volume of the liquid medicine is 10 (1.0 × 10) in order to obtain a liquid medicine having a more excellent effect of the present invention. 1 ) or more is preferable, and 1.0 × 10 2 Preferably, it is 50 or less, more preferably 35 or less, and particularly preferably 25 or less.

[0070] <Water> The chemical solution may contain water. The water is not particularly limited, and examples thereof include distilled water, ion-exchanged water, and pure water. Water is not included in the organic impurities. 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 manufacturing the chemical solution, or when water is mixed during the manufacturing process of the chemical solution (e.g., contamination).

[0071] The water content in the chemical solution is not particularly limited, but is generally preferably 0.05 to 2.0 mass % relative to the total mass of the chemical solution. The water content in the chemical solution refers to the water content measured using an apparatus that employs the Karl Fischer water content determination method as the measurement principle.

[0072] <Resin> The chemical solution may further contain a resin. A preferred resin is a resin P having a group that decomposes under the action of an acid to generate a polar group. A more preferred resin is a resin having a repeating unit represented by formula (AI) described below, which is a resin whose solubility in a developer primarily composed of an organic solvent decreases under the action of an acid. A resin having a repeating unit represented by formula (AI) described below has a group that decomposes under the action of an acid to generate an alkali-soluble group (hereinafter also referred to as an "acid-decomposable group"). Examples of the polar group include an alkali-soluble group, such as a carboxy group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a phenolic hydroxyl group, and a sulfo group.

[0073] In the acid-decomposable group, the polar group is protected by a group that is detached by an acid (acid-detachable group). Examples of the acid-detachable group include -C(R 36 )(R 37 )(R 38 ), -C(R 36 )(R 37 )(OR 39 ), and -C(R 01 )(R 02 )(OR 39 ) etc.

[0074] In the formula, R 36 ~R 39 R each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. 36 and R 37 may be bonded to each other to form a ring.

[0075] R 01 and R 02each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

[0076] The resin P whose solubility in a developer containing an organic solvent as its main component decreases due to the action of an acid will be described in detail below.

[0077] (Formula (AI): Repeating unit having an acid-decomposable group) Resin P preferably contains a repeating unit represented by formula (AI).

[0078] [ka]

[0079] In formula (AI), Xa1 represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Ra1 to Ra3 each independently represent an alkyl group (straight-chain or branched) or a cycloalkyl group (monocyclic or polycyclic). Two of Ra1 to Ra3 may be bonded to form a cycloalkyl group (monocyclic or polycyclic).

[0080] Examples of the alkyl group represented by Xa1, which may have a substituent, include a methyl group and -CH2-R 11 Examples of such groups include groups represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

[0081] Examples of the divalent linking group for T include an alkylene group, a -COO-Rt- group, and a -O-Rt- group, where Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH2- group, a -(CH2)2- group, or a -(CH2)3- group.

[0082] The alkyl groups Ra1 to Ra3 are preferably those having 1 to 4 carbon atoms.

[0083] The cycloalkyl groups of Ra1 to Ra3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group or a cyclohexyl group, or polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. The cycloalkyl group formed by combining two of Ra1 to Ra3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms.

[0084] In the cycloalkyl group formed by combining two of Ra1 to Ra3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, or a group having a heteroatom such as a carbonyl group.

[0085] In the repeating unit represented by formula (AI), for example, Ra1 is a methyl group or an ethyl group, and Ra2 and Ra3 are bonded to form the above-mentioned cycloalkyl group.

[0086] Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxy group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms), and the like, preferably having 8 or less carbon atoms.

[0087] The content of the repeating unit represented by formula (AI) is preferably from 20 to 90 mol %, more preferably from 25 to 85 mol %, and even more preferably from 30 to 80 mol %, based on all repeating units in the resin P.

[0088] (Repeating unit having a lactone structure) Furthermore, the resin P preferably contains a repeating unit Q having a lactone structure.

[0089] The repeating unit Q having a lactone structure preferably has a lactone structure in the side chain, and more preferably is a repeating unit derived from a (meth)acrylic acid derivative monomer. The repeating unit Q having a lactone structure may be used alone or in combination of two or more kinds, but it is preferred to use one kind alone. The content of the repeating unit Q having a lactone structure relative to all repeating units in the resin P is preferably from 3 to 80 mol %, more preferably from 3 to 60 mol %.

[0090] The lactone structure is preferably a 5- to 7-membered lactone structure, and more preferably a structure in which another ring structure is condensed with the 5- to 7-membered lactone structure to form a bicyclo structure or a spiro structure. The lactone structure preferably has a repeating unit having a lactone structure represented by any one of the following formulas (LC1-1) to (LC1-17): The lactone structure is preferably a lactone structure represented by formula (LC1-1), formula (LC1-4), formula (LC1-5), or formula (LC1-8), and more preferably a lactone structure represented by formula (LC1-4).

[0091] [ka]

[0092] The lactone structure portion may have a substituent (Rb2). Preferred examples of the substituent (Rb2) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxy group, a halogen atom, a hydroxyl group, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or greater, multiple substituents (Rb2) may be the same or different, and multiple substituents (Rb2) may be bonded to each other to form a ring.

[0093] (Repeating unit having a phenolic hydroxyl group) Furthermore, the resin P may contain a repeating unit having a phenolic hydroxyl group. Examples of the repeating unit having a phenolic hydroxyl group include a repeating unit represented by the following general formula (I).

[0094] [ka]

[0095] During the ceremony, R 41 , R 42 and R 43 each independently represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. 42 may be bonded to Ar4 to form a ring, in which case R 42 represents a single bond or an alkylene group.

[0096] X4 is a single bond, -COO-, or -CONR 64 - represents R 64 represents a hydrogen atom or an alkyl group. L4 represents a single bond or an alkylene group. Ar4 represents an (n+1)-valent aromatic ring group, R 42 When it combines with the group to form a ring, it represents an (n+2)-valent aromatic ring group. n represents an integer of 1 to 5.

[0097] R in general formula (I) 41 , R 42 and R 43 The alkyl group is preferably an alkyl group having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, or a dodecyl group, which may have a substituent, more preferably an alkyl group having 8 or less carbon atoms, and even more preferably an alkyl group having 3 or less carbon atoms.

[0098] R in general formula (I) 41 , R 42 and R 43 The cycloalkyl group may be monocyclic or polycyclic, and is preferably a monocyclic cycloalkyl group having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, or a cyclohexyl group, which may have a substituent.

[0099] R in general formula (I) 41 , R 42 and R 43 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, with a fluorine atom being preferred.

[0100] R in general formula (I) 41 , R 42 and R 43 The alkyl group contained in the alkoxycarbonyl group of the above R 41 , R 42 and R 43 The same alkyl groups as those in the above are preferred.

[0101] Examples of the substituent in each of the above groups include an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amido group, a ureido group, a urethane group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group, a thioether group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a cyano group, and a nitro group, and the number of carbon atoms in the substituent is preferably 8 or less.

[0102] Ar4 represents an (n+1)-valent aromatic ring group. When n is 1, the divalent aromatic ring group may have a substituent, and examples thereof include arylene groups having 6 to 18 carbon atoms, such as a phenylene group, a tolylene group, a naphthylene group, and an anthracenylene group, and aromatic ring groups containing a heterocycle, such as thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0103] Specific examples of the (n+1)-valent aromatic ring group when n is an integer of 2 or greater include groups obtained by removing any (n-1) hydrogen atoms from the above-mentioned specific examples of the divalent aromatic ring group. The (n+1)-valent aromatic ring group may further have a substituent.

[0104] Examples of the substituent that the above-mentioned alkyl group, cycloalkyl group, alkoxycarbonyl group, alkylene group, and (n+1)-valent aromatic ring group may have include, for example, R 41 , R 42 and R 43 alkoxy groups such as a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, and a butoxy group; and aryl groups such as a phenyl group.

[0105] -CONR represented by X4 64 -(R 64 represents a hydrogen atom or an alkyl group. 64 Examples of the alkyl group include alkyl groups having 20 or less carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, hexyl, 2-ethylhexyl, octyl, and dodecyl groups, which may have a substituent, and alkyl groups having 8 or less carbon atoms are more preferred.

[0106] X4 is preferably a single bond, -COO- or -CONH-, more preferably a single bond or -COO-.

[0107] The alkylene group in L4 is preferably an alkylene group having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group, which may have a substituent.

[0108] Ar4 is preferably an aromatic ring group having 6 to 18 carbon atoms which may have a substituent, and more preferably a benzene ring group, a naphthalene ring group or a biphenylene ring group.

[0109] The repeating unit represented by general formula (I) preferably has a hydroxystyrene structure, that is, Ar4 is preferably a benzene ring group.

[0110] The content of repeating units having a phenolic hydroxyl group relative to all repeating units in the resin P is preferably from 0 to 50 mol %, more preferably from 0 to 45 mol %, and even more preferably from 0 to 40 mol %.

[0111] (Repeating unit containing an organic group having a polar group) Resin P may further contain a repeating unit containing an organic group having a polar group, particularly a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group, which improves substrate adhesion and developer affinity. The alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group, and the polar group is preferably a hydroxyl group or a cyano group.

[0112] When the resin P contains a repeating unit containing an organic group having a polar group, the content thereof is preferably 1 to 50 mol %, more preferably 1 to 30 mol %, still more preferably 5 to 25 mol %, and particularly preferably 5 to 20 mol %, based on the total repeating units in the resin P.

[0113] (Repeating unit represented by general formula (VI)) Resin P may contain a repeating unit represented by the following general formula (VI).

[0114] [ka]

[0115] In general formula (VI), R 61 , R 62 and R 63 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. 62 may be bonded to Ar6 to form a ring, in which case R 62 represents a single bond or an alkylene group. X6 is a single bond, -COO-, or -CONR 64 - represents R 64 represents a hydrogen atom or an alkyl group. L6 represents a single bond or an alkylene group. Ar6 represents an (n+1)-valent aromatic ring group, R 62 When it combines with the group to form a ring, it represents an (n+2)-valent aromatic ring group. When n≧2, each Y2 independently represents a hydrogen atom or a group which is eliminated by the action of an acid, provided that at least one Y2 represents a group which is eliminated by the action of an acid. n represents an integer of 1 to 4.

[0116] As the group Y2 which is eliminated by the action of an acid, a structure represented by the following general formula (VI-A) is preferred.

[0117] [ka]

[0118] L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining an alkylene group with an aryl group. M represents a single bond or a divalent linking group. Q represents an alkyl group, a cycloalkyl group which may contain a heteroatom, an aryl group which may contain a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, or an aldehyde group. At least two of Q, M and L1 may be bonded to form a ring (preferably a 5- or 6-membered ring).

[0119] The repeating unit represented by the above general formula (VI) is preferably a repeating unit represented by the following general formula (3).

[0120] [ka]

[0121] In general formula (3), Ar3 represents an aromatic ring group. R3 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, an acyl group, or a heterocyclic group. M3 represents a single bond or a divalent linking group. Q3 represents an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group. At least two of Q3, M3 and R3 may be bonded to form a ring.

[0122] The aromatic ring group represented by Ar3 is the same as Ar6 in the above general formula (VI) when n is 1, and is preferably a phenylene group or a naphthylene group, more preferably a phenylene group.

[0123] (Repeating unit having a silicon atom in the side chain) Resin P may further contain a repeating unit having a silicon atom in the side chain. Examples of repeating units having a silicon atom in the side chain include (meth)acrylate repeating units having a silicon atom and vinyl repeating units having a silicon atom. The repeating unit having a silicon atom in the side chain is typically a repeating unit having a group having a silicon atom in the side chain, and examples of the group having a silicon atom include a trimethylsilyl group, a triethylsilyl group, a triphenylsilyl group, a tricyclohexylsilyl group, a tristrimethylsiloxysilyl group, a tristrimethylsilylsilyl group, a methylbistrimethylsilylsilyl group, a methylbistrimethylsiloxysilyl group, a dimethyltrimethylsilylsilyl group, a dimethyltrimethylsiloxysilyl group, and cyclic or linear polysiloxanes such as those shown below, or cage, ladder, or random silsesquioxane structures. In the formula, R and R 1 Each independently represents a monovalent substituent. * represents a bond.

[0124] [ka]

[0125] Preferred examples of repeating units having the above group include repeating units derived from an acrylate compound or methacrylate compound having the above group, and repeating units derived from a compound having the above group and a vinyl group.

[0126] When the resin P has the repeating unit having a silicon atom in the side chain, the content thereof is preferably 1 to 30 mol %, more preferably 5 to 25 mol %, and even more preferably 5 to 20 mol %, based on the total repeating units in the resin P.

[0127] The weight-average molecular weight of Resin P, as measured by GPC (Gel Permeation Chromatography) in terms of polystyrene, is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 5,000 to 15,000. By setting the weight-average molecular weight to 1,000 to 200,000, it is possible to prevent deterioration in heat resistance and dry etching resistance, and also to prevent deterioration in developability and deterioration in film-formability due to an increase in viscosity.

[0128] The dispersity (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0.

[0129] In the chemical solution, the content of the resin P is preferably 50 to 99.9 mass % of the total solid content, and more preferably 60 to 99.0 mass %. In addition, in the chemical solution, one type of resin P may be used, or a plurality of types may be used in combination.

[0130] Other components contained in the chemical solution (e.g., acid generator, basic compound, quencher, hydrophobic resin, surfactant, solvent, etc.) can all be known ones. Examples of other components include components contained in actinic ray-sensitive or radiation-sensitive resin compositions described in JP 2013-195844 A, JP 2016-057645 A, JP 2015-207006 A, WO 2014 / 148241 A, JP 2016-188385 A, and JP 2017-219818 A.

[0131] [Chemical use] The chemical solutions according to the above embodiments are preferably used in the manufacture of semiconductor devices, and more preferably used to form fine patterns with a node of 10 nm or less (for example, processes including pattern formation using EUV). The chemical liquid according to the above embodiment is more preferably used as a chemical liquid (pre-wet liquid, developer, rinse liquid, resist liquid solvent, stripper liquid, etc.) used in a resist process in which the pattern width and / or pattern spacing is 17 nm or less (preferably 15 nm or less, more preferably 12 nm or less) and / or the resulting wiring width and / or wiring spacing is 17 nm or less, in other words, for manufacturing a semiconductor device manufactured using a resist film in which the pattern width and / or pattern spacing is 17 nm or less.

[0132] Specifically, in the manufacturing process of semiconductor devices, which includes a lithography process, an etching process, an ion implantation process, a stripping process, etc., the liquid is used to treat organic substances after each process or before moving to the next process, and is suitably used as a pre-wet liquid, a developer, a rinse liquid, a stripping liquid, etc. For example, it can also be used to rinse the edge line of a semiconductor substrate before and after resist coating. The chemical liquid can also be used as a diluent for the resin contained in the resist liquid, or as a solvent contained in the resist liquid. The chemical liquid may also be diluted with other organic solvents and / or water.

[0133] Furthermore, the chemical solution can be used for purposes other than the manufacture of semiconductor devices, and can also be used as a developer for polyimide, resist for sensors, resist for lenses, etc., and as a rinse solution. The chemical liquid can also be used as a solvent for medical or cleaning purposes, and is particularly suitable for cleaning containers, pipes, and substrates (e.g., wafers, glass, etc.).

[0134] In particular, this chemical solution exhibits excellent effects when applied to pre-wet solutions, developer solutions, and rinse solutions in pattern formation using EUV (extreme ultraviolet) rays.

[0135] [Method of manufacturing chemical solution] The method for producing the chemical solution is not particularly limited, and any known production method can be used. Among them, in order to obtain a chemical solution having a more excellent effect of the present invention, the method for producing the chemical solution preferably includes a filtration step of filtering a material to be purified containing an organic solvent using a filter to obtain the chemical solution.

[0136] The material to be purified used in the filtration step is procured by purchase or the like, and obtained by reacting raw materials. As the material to be purified, it is preferable to use the metal-containing particles and / or those with a low content of impurities, as already explained. Examples of commercially available products of such materials to be purified include those called "high-purity grade products."

[0137] The method for reacting raw materials to obtain a product to be purified (typically, a product to be purified containing an organic solvent) is not particularly limited, and known methods can be used. For example, there is a method for reacting one or more raw materials in the presence of a catalyst to obtain an organic solvent. More specifically, examples of such methods include 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(C2H5)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); and a method of reacting lactic acid and ethanol to obtain ethyl lactate.

[0138] <Filtration process> The method for producing a chemical solution according to an embodiment of the present invention includes a filtration step of filtering the material to be purified using a filter to obtain a chemical solution. The method for filtering the material to be purified using a filter is not particularly limited, but it is preferable to pass the material to be purified (liquid) through a filter unit having a housing and a cartridge filter housed in the housing, with or without pressure.

[0139] Filter pore size The pore size of the filter is not particularly limited, and filters having pore sizes commonly used for filtering materials to be purified can be used. In particular, the pore size of the filter is preferably 200 nm or less, more preferably 20 nm or less, even more preferably 10 nm or less, particularly preferably 5 nm or less, and most preferably 3 nm or less, because this makes it easier to control the number of particles having a particle size of 0.5 to 17 nm contained in the drug solution within 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 and pore size distribution of a filter refer to the pore size and pore size distribution determined by the bubble point of isopropanol (IPA) or HFE-7200 ("Novec 7200", manufactured by 3M, hydrofluoroether, C4F9OC2H5).

[0140] A filter with a pore size of 5.0 nm or less is preferable because it is easier to control the number of particles with a particle size of 0.5 to 17 nm contained in the drug solution. Hereinafter, a filter with a pore size of 5 nm or less will also be referred to as a "micropore filter." The micropore filter may be used alone or in combination with a filter having a different pore size. From the viewpoint of superior productivity, it is preferable to use the micropore filter in combination with a filter having a larger pore size. In this case, clogging of the micropore filter can be prevented by passing the purified product, which has been previously filtered through a filter having a larger pore size, through the micropore filter. 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.

[0141] The sequential use of two or more filters with different pore sizes is not particularly limited, but may include the method of sequentially arranging the filter units described above along the pipeline through which the purified product is transported. In this case, if the flow rate per unit time of the purified product is to be constant throughout the entire pipeline, filter units with smaller pore sizes may be subjected to greater pressure than filter units with larger pore sizes. In this case, it is preferable to arrange a pressure control valve and a damper between the filter units to constant the pressure applied to the filter units with smaller pore sizes, or to arrange filter units containing the same filter in parallel along the pipeline to increase the filtration area. This allows for more stable control of the number of particles of 0.5 to 17 nm contained in the drug solution.

[0142] Filter material The filter material is not particularly limited, and known filter materials can be used. Specific examples of resins include polyamides such as 6-nylon and 6,6-nylon; polyolefins such as polyethylene and polypropylene; polystyrene; polyimide; polyamideimide; poly(meth)acrylate; 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 (especially 6,6-nylon), polyolefins (especially polyethylene), poly(meth)acrylate, and polyfluorocarbons (especially polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA)) is preferred, as they have superior solvent resistance and the resulting chemical solution exhibits superior defect suppression performance. These polymers may 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.

[0143] The filter may also be surface-treated. The surface treatment method is not particularly limited, and known methods can be used. Examples of surface treatment methods include chemical modification treatment, plasma treatment, hydrophobic treatment, coating, gas treatment, and sintering.

[0144] Plasma treatment is preferred because it hydrophilizes the filter surface. The water contact angle on the filter surface hydrophilized 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, and even more preferably 30° or less.

[0145] As the chemical modification treatment, a method of introducing ion exchange groups into the substrate is preferred. That is, the filter is preferably one in which ion exchange groups are introduced into the substrate, using any of the materials listed above as the substrate. Typically, a filter including a substrate having ion exchange groups on its surface is preferred. The surface-modified substrate is not particularly limited, and in terms of ease of production, one in which ion exchange groups are introduced into the above polymer is preferred.

[0146] Examples of the ion exchange group include a sulfonic acid group, a carboxyl group, and a phosphate group as a cation exchange group, and a quaternary ammonium group as an anion exchange group. The method for introducing the ion exchange group into the polymer is not particularly limited, but includes a method in which a compound having an ion exchange group and a polymerizable group is reacted with the polymer to typically perform grafting.

[0147] The method for introducing ion exchange groups is not particularly limited. For example, fibers of the above resins are irradiated with ionizing radiation (α-rays, β-rays, γ-rays, X-rays, electron beams, etc.) to generate active moieties (radicals) in the resin. The irradiated resin is then immersed in a monomer-containing solution to graft polymerize the monomer onto the substrate. As a result, the monomer is bonded to the polyolefin fiber as a graft-polymerized side chain. The resin having this generated polymer as a side chain is then contact-reacted with a compound having an anion exchange group or a cation exchange group, thereby introducing ion exchange groups into the graft-polymerized side chain polymer, yielding the final product.

[0148] The filter may also be constructed by combining a woven or nonwoven fabric on which ion exchange groups have been formed by radiation graft polymerization with a conventional filtering material such as glass wool, woven or nonwoven fabric.

[0149] The use of a filter having ion exchange groups makes it easy to control the content of metal atom-containing particles in the chemical solution within a desired range. The material of the filter having ion exchange groups is not particularly limited, but examples include polyfluorocarbons and polyolefins with ion exchange groups introduced therein, and polyfluorocarbons with ion exchange groups introduced therein are more preferred. The pore size of the filter having ion exchange groups is not particularly limited, but is preferably 1 to 30 nm, more preferably 5 to 20 nm. The filter having ion exchange groups may also serve as the filter having the smallest pore size described above, or may be used separately from the filter having the smallest pore size. In particular, in order to obtain a chemical solution having a more excellent effect of the present invention, it is preferable that the filtration step uses a filter having ion exchange groups and a filter having the smallest pore size but not having ion exchange groups in combination. 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.

[0150] Furthermore, when the filter material is polyamide (particularly nylon), the content of high-boiling point organic compounds and particles U in the chemical solution can be more easily controlled, and in particular, the content of particles U in the chemical solution can be even more easily controlled. Therefore, it is preferable to use two or more filters made of different materials as the filters used in the filtration process, and it is more preferable to use two or more filters selected from the group consisting of polyolefins, polyfluorocarbons, polyamides, and those into which ion exchange groups have been introduced.

[0151] ·Porous 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 refers to 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 filter manufacturing method. For example, porous membranes can be obtained by sintering powders of resins or the like, and fibrous membranes can be obtained by methods such as electrospinning, electroblowing, and meltblowing, each of which has a different pore structure.

[0152] By "porous membrane" is meant a membrane that retains components of a product to be purified, such as gels, particles, colloids, cells, and poly-oligomers, while allowing components substantially smaller than the pores to pass through the pores. The retention of components of a product by a porous membrane can depend on operating conditions, such as face velocity, the use of surfactants, pH, and combinations thereof, and can also depend on the pore size and structure of the porous membrane and the size and structure of the particles to be removed (e.g., hard particles or gels).

[0153] When the product to be purified contains particles U (which may be in gel form) as impurities, particles containing high-boiling organic compounds are often negatively charged, and polyamide filters function as non-sieving membranes to remove such particles. Typical non-sieving membranes include nylon membranes such as nylon-6 membranes and nylon-6,6 membranes, but are not limited to these. It is noted that "non-sieving" retention mechanisms, as used herein, refer to retention that occurs through mechanisms such as obstruction, diffusion, and adsorption that are not related to the pressure drop or pore size of the filter.

[0154] Non-sieving retention includes retention mechanisms such as obstruction, diffusion, and adsorption, which remove target particles in the product, regardless of the filter's pressure drop or pore size. Particle adsorption to the filter surface can be mediated, for example, by intermolecular van der Waals and electrostatic forces. The obstruction effect occurs when particles moving through a non-sieving membrane layer with a tortuous path cannot change direction quickly enough to avoid contact with the non-sieving membrane. Diffusion-based particle transport results primarily from the random or Brownian motion of small particles, which creates a certain probability of particle collision with the filter material. Non-sieving retention mechanisms can be active when there is no repulsive force between the particle and the filter.

[0155] UPE (ultra-high molecular weight polyethylene) filters are typically sieving membranes, meaning membranes that capture particles primarily through sieving retention mechanisms or membranes optimized for capturing particles through sieving retention mechanisms. 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 can be 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.

[0156] The material of the fiber layer is not particularly limited as long as it is a polymer capable of forming a fiber layer. Examples of polymers include polyamides. Examples of polyamides include nylon 6 and nylon 6,6. The polymer forming the fiber membrane may be poly(ether sulfone). 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).

[0157] The method for producing the fiber membrane is not particularly limited, and known methods can be used, such as electrospinning, electroblowing, and meltblowing.

[0158] The pore structure of the porous membrane (for example, a porous membrane containing UPE, PTFE, etc.) is not particularly limited, and examples of the pore shape include lace-like, string-like, and node-like. The pore size distribution in the porous membrane and the distribution of its positions within the membrane are not particularly limited. The size distribution may be narrower and the distribution positions within the membrane may be symmetrical. Alternatively, the size distribution may be wider and the distribution positions within the membrane may be asymmetrical (the above membrane is also referred to as an "asymmetric porous membrane"). In an asymmetric porous membrane, the pore size varies within the membrane, and typically, the pore size increases from one surface of the membrane to the other. In this case, the surface with more pores with larger pore sizes is referred to as the "open side," and the surface with more pores with smaller pore sizes is also referred to as the "tight side." Asymmetric porous membranes include, for example, membranes in which the size of the pores is smallest at a certain position within the thickness of the membrane (also called "hourglass shape").

[0159] With asymmetric porous membranes, the primary side can have larger pore size, in other words the primary side is open, creating a pre-filtration effect.

[0160] 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 these, ultra-high molecular weight polyethylene is preferred as a material for the porous membrane. Ultra-high molecular weight polyethylene refers to thermoplastic polyethylene with an extremely long chain, and preferably has a molecular weight of one million or more, typically 2 to 6 million.

[0161] The filters used in the filtration step preferably include two or more filters with different pore structures, and more preferably include a porous membrane filter and a fiber membrane filter. Specifically, it is preferable to use a nylon fiber membrane filter and a UPE porous membrane filter in combination.

[0162] As described above, the filtration step according to an embodiment of the present invention is preferably a multistage filtration step in which the material to be purified is passed through two or more types of filters that differ in at least one property selected from the group consisting of filter material, pore size, and pore structure.

[0163] (multi-stage filtration process) The multistage filtration process can be carried out using a known purification apparatus. Figure 1 is a schematic diagram showing a typical example of a purification apparatus capable of carrying out the multistage filtration process. The purification apparatus 10 has a production tank 11, a filtration device 16, and a filling device 13, and the above-mentioned respective units are connected by a pipeline 14. Filtration device 16 has filter units 12(a) and 12(b) connected by a pipeline 14. An adjustment valve 15(a) is disposed in the pipeline between filter units 12(a) and 12(b). Although FIG. 1 illustrates a case where the number of filter units is two, three or more filter units may be used.

[0164] In Fig. 1, the product to be purified is stored in production tank 11. Next, a pump (not shown) disposed in pipeline 14 is operated, and the product to be purified is sent from production tank 11 through pipeline 14 to filtration device 16. The direction of transfer of the product to be purified in purification device 10 is indicated by F1 in Fig. 1.

[0165] Filtration device 16 is composed of filter units 12(a) and 12(b) connected by a pipeline 14, and each of the two filter units houses a cartridge filter having filters that differ in at least one type selected from the group consisting of pore size, material, and pore structure. Filtration device 16 has the function of filtering the product to be purified that is supplied through the pipeline. There are no particular restrictions on the filters housed in each filter unit, but it is preferable that the filter with the smallest pore size be housed in filter unit 12(b).

[0166] As the pump operates, the product is supplied to filter unit 12(a) and filtered. The product filtered by filter unit 12(a) is depressurized by regulating valve 15(a) as needed, and is supplied to filter unit 12(b) and filtered.

[0167] The refining device does not necessarily have to have regulating valve 15(a). Even if regulating valve 15(a) is provided, its position does not have to be on the upstream side of filter unit 12(b) and may be on the upstream side of filter unit 12(a). Furthermore, a device other than a regulating valve may be used to adjust the supply pressure of the product to be purified. Examples of such a device include a damper.

[0168] In addition, in the filtration device 16, each filter forms a cartridge filter, but the filters that can be used in the purification method according to this embodiment are not limited to the above-mentioned form. For example, the product to be purified may be passed through a filter formed in a flat plate shape.

[0169] Furthermore, in the above-mentioned purification apparatus 10, the purified product after filtering through filter unit 12(b) is transferred to filling device 13 and stored in a container. However, the filtration apparatus for carrying out the above-mentioned purification method is not limited to this, and may be configured so that the purified product filtered through filter unit 12(b) is returned to production tank 11 and passed through filter units 12(a) and 12(b) again. This type of filtration method is called circulating filtration. In purifying a purified product by circulating filtration, at least one of two or more types of filters is used two or more times. In this specification, the operation of returning the filtered purified product filtered through each filter unit to the production tank is counted as one circulation cycle. The number of circulation times may be appropriately selected depending on the components in the product to be purified.

[0170] The material of the liquid-contacting parts of the above-mentioned purification device (meaning the inner wall surfaces, etc., that may come into contact with the product to be purified and the chemical solution) is not particularly limited, but it is preferable that they be formed from at least one material selected from the group consisting of non-metallic materials and electropolished metallic materials (hereinafter, these will be collectively referred to as "corrosion-resistant materials"). For example, when the liquid-contacting parts of a production tank are formed from a corrosion-resistant material, this means that the production tank itself is made of a corrosion-resistant material, or the inner wall surfaces, etc., of the production tank are coated with a corrosion-resistant material.

[0171] The non-metallic material is not particularly limited, and known materials 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, tetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluorochloroethylene-ethylene copolymer resin, vinylidene fluoride resin, trifluorochloroethylene copolymer resin, and vinyl fluoride resin.

[0172] The metal material is not particularly limited, and known materials can be used. The metal material may be, for example, a metal material having a total chromium and nickel content of more than 25 mass% relative to the total mass of the metal material, with a content of 30 mass% or more being preferred. There is no particular upper limit to the total chromium and nickel content in the metal material, but it is preferably 90 mass% or less. Examples of metal materials include stainless steel and nickel-chromium alloys.

[0173] 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 preferred, and an austenitic stainless steel containing 8% or more by mass of nickel is 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).

[0174] 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 preferred. Examples of nickel-chromium alloys include Hastelloy (trade name, the same applies hereinafter), Monel (trade name, the same applies hereinafter), and Inconel (trade name, the same applies hereinafter), etc. More specific 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%), etc. Furthermore, the nickel-chromium alloy may further contain boron, silicon, tungsten, molybdenum, copper, cobalt, and the like in addition to the above alloy, as required.

[0175] The method for electrolytically polishing a metal material is not particularly limited, and any known method can be used, such as those described in paragraphs 0011 to 0014 of JP 2015-227501 A and paragraphs 0036 to 0042 of JP 2008-264929 A.

[0176] It is believed that electrolytic polishing of metal materials results in a higher chromium content in the surface passive layer than in the parent phase, and therefore, it is believed that the use of a refining device with wetted parts made of electrolytically polished metal materials makes it difficult for metal-containing particles to leak into the product being refined. The metal material may be buffed. The buffing method is not particularly limited, and known methods can be used. The size of the abrasive grains used for the buffing finish is not particularly limited, but #400 or smaller is preferred, as this tends to reduce the surface irregularities of the metal material. The buffing is preferably performed before electrolytic polishing.

[0177] <Other processes> The method for producing a chemical solution according to the embodiment of the present invention is not particularly limited as long as it includes a filtration step, and may further include steps other than the filtration step, such as a distillation step, a reaction step, and a static elimination step.

[0178] (Distillation process) The distillation step is a step of distilling a material to be purified containing an organic solvent to obtain a distilled material to be purified. The method for distilling the material to be purified is not particularly limited, and known methods can be used. A typical example is a method in which a distillation column is placed on the upstream side of the purification apparatus already described, and the distilled material to be purified 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 described.

[0179] (Reaction step) The reaction step is a step in which raw materials are reacted to produce a product to be purified that contains an organic solvent as a reaction product. The method for producing the product to be purified is not particularly limited, and known methods can be used. A typical example is a method in which a reaction vessel is placed on the upstream side of the production tank (or distillation column) of the purification apparatus already described, and the reactant is introduced into the production tank (or distillation column). In this case, the liquid-contacting parts of the reaction vessel are not particularly limited, but are preferably made of the corrosion-resistant materials already described.

[0180] (static elimination process) The charge removal step is a step of removing static electricity from the material to be purified, thereby reducing 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, such as contacting the product to be purified with a conductive material. The contact time for contacting 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 second. Examples of conductive materials include stainless steel, gold, platinum, diamond, and glassy carbon. As a method for bringing the material to be purified into contact with the 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.

[0181] It is preferable that the purification of the target substance, including the opening of containers, cleaning of containers and equipment, storage of solutions, and analysis, be all performed in a clean room. The clean room is preferably a clean room with a cleanliness 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.

[0182] The storage temperature of the drug solution is not particularly limited, but a storage temperature of 4°C or higher is preferred, as this makes it more difficult for impurities contained in trace amounts in the drug solution to be eluted, resulting in better effects of the present invention.

[0183] [Medicinal solution container] The drug solution produced by the above purification method may be stored in a container until use. Such a container and the chemical solution (or resist composition) contained therein are collectively referred to as a chemical solution container. The chemical solution is taken out of the stored chemical solution container and used.

[0184] The container for storing the chemical solution is preferably one that is highly clean inside and has little elution of impurities, and is intended 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.

[0185] As the 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 drug solution. Examples of such containers include the container described in JP 2015-123351 A.

[0186] The liquid-contacting portion of the container is preferably made of the corrosion-resistant material or glass described above. In order to obtain a more excellent 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 more preferably that the entire liquid-contacting portion is made of the above material. [Example]

[0187] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment 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 construed as being limited by the following examples.

[0188] 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 clean rooms meeting ISO Class 2 or 1 standards. To improve measurement accuracy, when measuring the content of organic impurities and the content of metal atoms that are below the detection limit in normal measurements, the chemical solutions were concentrated to 1 / 100th their volume and the content was calculated by converting it to the concentration of the solution before concentration. Note that the surfaces of the equipment used for purification, as well as tools such as filters and containers, that came into contact with the chemical solutions were thoroughly washed with chemical solutions that had been purified using the same method before use.

[0189] [Purification of Chemical Solution 1] A commercially available product containing cyclohexanone (CHN) as an organic solvent was prepared and filtered using a purification system similar to that shown in Figure 1, except that it had four filter units arranged in series along a pipeline, a filtration device without an adjustment valve, and a pipeline through which the filtered product could be returned to the production tank after being filtered by the most downstream filter unit, to produce a chemical solution. Each filter unit had the following filters arranged from the upstream side (referred to as filters 1 to 4 in Table 1). Polypropylene filter (pore size: 200 nm, porous membrane, indicated as "PP" in the table) Polyfluorocarbon filter with ion exchange groups (pore size: 20 nm, fiber membrane made of a polymer of PTFE and PES (polyethylene sulfonic acid), indicated as "IEX" in the table) Nylon filter (pore size: 10 nm, fiber membrane, listed as "Nylon" in the table) UPE filter (pore size: 3 nm, porous membrane, indicated as "UPE" in the table) The purified product that had passed through the four filter units was returned to the production tank, and this process was repeated eight times to obtain a drug solution.

[0190] [Purification of chemical solutions 2 to 30] Chemical solutions 2 to 30 were obtained by purifying a material to be purified containing an organic solvent listed in Table 1 under the conditions listed in Table 1. Each chemical solution was obtained by passing the material to be purified through each filter listed in Table 1, in order from the first filter to the fourth filter (a chemical solution with a blank filter column indicates that the filter was not used. For example, chemical solution 2 was passed through the first filter to the fourth filter), and repeating this process the number of times listed in the "circulation count." The materials listed in Table 1 were procured from different lots, and therefore the components other than the organic solvent initially contained in each material may differ.

[0191] The abbreviations in Table 1 represent the following: PGMEA / PGME (7:3): A 7:3 (v / v) mixture of PGMEA and PGME nBA: n-butyl acetate ·iAA: Isoamyl acetate MIBC: Methyl isobutyl carbinol IPA: Isopropanol PC / PGMEA (1:9): A 1:9 (v / v) mixture of PC and PGMEA EL: Ethyl lactate IEX / 10nm: IEX filter with pore size of 10nm PTFE: Polytetrafluoroethylene filter (porous membrane) UPE: Ultra-high molecular weight polyethylene filter (porous membrane) Nylon: Nylon filter (fiber membrane)

[0192] [Table 1]

[0193] [Evaluation of the number of particles with diameters of 0.5 to 17 nm contained in a drug solution] The content (number of particles contained) of particles with a particle diameter of 0.5 to 17 nm in the drug solution was measured by the following method. First, a certain amount of chemical solution was applied to a silicon substrate to form a substrate with a chemical solution layer, and the surface of the substrate with the chemical solution layer was scanned with a laser beam to detect scattered light. This allowed the location and particle size of defects present on the surface of the substrate with the chemical solution layer to be identified. Next, elemental analysis was performed using EDX (energy dispersive X-ray) analysis based on the defect locations to examine the composition of the defects. This method was used to determine the number of metal nanoparticles, Pb nanoparticles, and Ti nanoparticles on the substrate, and this was used to calculate the number of particles contained per unit volume of the chemical solution (particles / cm). 3 The particle size distribution of the metal nanoparticles was also determined by the above method. Similarly, the composition of the metal nanoparticles (elemental metal and oxide of metal atoms) and the state of association with high-boiling organic compounds were also identified. The analysis was performed using a combination of KLA-Tencor's wafer inspection system "SP-5" and Applied Materials' fully automated defect review and classification system "SEMVision G6." The presence or absence of high-boiling-point organic compounds was also measured using gas chromatography mass spectrometry.

[0194] In addition, for samples in which particles of the desired particle size could not be detected due to the resolution of the measuring device, etc., the method described in paragraphs 0015 to 0067 of JP 2009-188333 A was used for detection. That is, SiO X A chemical solution layer was then formed on the SiO X A composite layer having a layer and a chemical solution layer applied thereon was dry-etched, the resulting protrusions were irradiated with light, scattered light was detected, the volume of the protrusions was calculated from the scattered light, and the particle diameter was calculated from the volume of the protrusions. Table 2 shows the measurement results for each chemical solution and the particle number ratio calculated based on the measurement results.

[0195] In Table 2, the abbreviations in the particle size distribution represent particles with particle sizes in the following ranges. "Less than 0.5": Metal-containing particles with a particle size of less than 0.5 nm "0.5-3": Metal nanoparticles with a particle size of 0.5 nm or more and less than 3 nm "3-5": Metal nanoparticles with a particle size of 3 nm or more and less than 5 nm "5-17": Metal nanoparticles with a particle size of 5 nm or more and 17 nm or less

[0196] [Table 2]

[0197] [Table 3]

[0198] Table 2 is divided into Table 2 (Part 1) and Table 2 (Part 2). The measurement results for each chemical solution are listed in the corresponding rows of the two tables. For example, in Chemical Solution 1, cyclohexanone is used as the organic solvent, and the number of particles containing metal nanoparticles is 1.0 x 10 4 pieces / cm 3 The particle size distribution (number %) of the metal-containing particles is as follows: 20% of the metal-containing particles have a particle size of less than 0.5 nm; 50% of the metal nanoparticles have a particle size of 0.5 nm or more but less than 3 nm; 20% of the metal nanoparticles have a particle size of 3 nm or more but less than 5 nm; and 10% of the metal nanoparticles have a particle size of 5 nm or more but less than 17 nm. Particle A accounts for 2% of the total metal nanoparticles by number, and the total of particle B and particle C accounts for 98%. A / (B+C) is 2.0×10 -2 It contains a high-boiling organic compound, and the particle U accounts for 94% of the total metal nanoparticles, and particle V accounts for 6% of the total number of particles, with a U / V ratio of 1.6 × 10 1 Among the metal nanoparticles, Pb nanoparticles are 1.3 × 10 2 pieces / cm 3 and Ti nanoparticles are 5.4 × 10 2 pieces / cm 3 and Pb / Ti is 2.4×10 -1 The other chemical solutions are listed in the table in the same manner as Chemical Solution 1.

[0199] [Example 1] The prepared chemical solution 1 was used as a pre-wet solution to evaluate the defect suppression performance. The resist compositions used were as follows:

[0200] [Resist Composition 1] Resist composition 1 was obtained by mixing the components in the following ratio. ·Resin (A-1): 0.77g Acid generator (B-1): 0.03g Basic compound (E-3): 0.03g PGMEA: 67.5g EL:75g

[0201] <Resin (A) etc.> (Synthesis Example 1) Synthesis of Resin (A-1) A 2-L flask was charged with 600 g of cyclohexanone and purged with nitrogen at a flow rate of 100 mL / min for one hour. Subsequently, 4.60 g (0.02 mol) of polymerization initiator V-601 (Wako Pure Chemical Industries, Ltd.) was added, and the internal temperature was raised to 80°C. Next, the following monomers and 4.60 g (0.02 mol) of polymerization initiator V-601 (Wako Pure Chemical Industries, Ltd.) were dissolved in 200 g of cyclohexanone to prepare a monomer solution. The monomer solution was added dropwise to the flask heated to 80°C over 6 hours. After completion of the dropwise addition, the mixture was allowed to react at 80°C for an additional 2 hours. 4-Acetoxystyrene 48.66g (0.3mol) 1-Ethylcyclopentyl methacrylate 109.4g (0.6mol) Monomer 1 22.2g (0.1mol)

[0202] [ka]

[0203] The reaction solution was cooled to room temperature and added dropwise to 3 L of hexane to precipitate the polymer. The filtered solid was dissolved in 500 mL of acetone and added dropwise again to 3 L of hexane. The filtered solid was dried under reduced pressure to obtain 160 g of 4-acetoxystyrene / 1-ethylcyclopentyl methacrylate / monomer 1 copolymer (A-1).

[0204] 10 g of the polymer obtained above, 40 mL of methanol, 200 mL of 1-methoxy-2-propanol, and 1.5 mL of concentrated hydrochloric acid were added to a reaction vessel, heated to 80°C, and stirred for 5 hours. The reaction solution was allowed to cool to room temperature and added dropwise to 3 L of distilled water. The filtered solid was dissolved in 200 mL of acetone and added dropwise again to 3 L of distilled water. The filtered solid was dried under reduced pressure to obtain Resin (A-1) (8.5 g). The weight-average molecular weight (Mw) measured by gel permeation chromatography (GPC) (solvent: THF (tetrahydrofuran)) in terms of standard polystyrene was 11,200, and the molecular weight dispersity (Mw / Mn) was 1.45. The composition and other details are shown in Table 3 below.

[0205] [Table 4]

[0206] <Photoacid generator (B)> The photoacid generator used was as follows:

[0207] [ka]

[0208] <Basic Compound (E)> The following basic compounds were used:

[0209] [ka]

[0210] (Residue defect suppression performance, bridge defect suppression performance, and stain defect suppression performance) The chemicals were evaluated for their ability to suppress residue defects, bridge defects, and stain defects using the following methods. 3S " was used. First, AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 200°C for 60 seconds to form a resist underlayer film with a thickness of 20 nm. A pre-wet liquid (chemical solution 1) was applied thereon, and then resist composition 1 was applied thereon and baked at 100°C for 60 seconds (PB: prebake) to form a resist film with a thickness of 30 nm.

[0211] This resist film was exposed to light using an EUV exposure system (manufactured by ASML; NXE3350, NA 0.33, Dipole 90°, outer sigma 0.87, inner sigma 0.35) through a reflective mask with a pitch of 20 nm and a pattern width of 15 nm. It was then baked at 85°C for 60 seconds (PEB: Post Exposure Bake). It was then developed with an organic solvent-based developer for 30 seconds and rinsed for 20 seconds. The wafer was then rotated at 2000 rpm for 40 seconds to form a line-and-space pattern with a pitch of 20 nm and a pattern line width of 15 nm.

[0212] An image of the above pattern was obtained, and the obtained image was analyzed using the above-mentioned analytical device to measure the number of residues in the unexposed area per unit area (referred to as "residue defect suppression performance" in Table 4) and the number of bridge-like defects between patterns (number of bridge defects, referred to as "bridge defect suppression performance" in Table 4). In addition, EDX (energy dispersive X-ray analysis) was performed at the coordinates where defects were detected. Defects in which no metal atoms were detected were defined as stain-like defects and counted (referred to as "stain defect suppression performance" in Table 4). The results were evaluated according to the following criteria and are shown in Table 4. In the evaluation criteria below, "number of defects" refers to the number of residue defects, the number of bridge defects, and the number of stain-like defects, respectively.

[0213] AA: Fewer than 30 defects. A: The number of defects was more than 30 but less than 60. B: The number of defects was 60 or more but less than 90. C: The number of defects was 90 or more but less than 120. D: The number of defects was 120 or more but less than 150. E: The number of defects was 150 or more but less than 180. F: The number of defects was 180 or more.

[0214] (Uniformity of pattern width) An image of the above pattern was acquired and analyzed using the above-mentioned analyzer to determine LWR (Line Width Roughness). That is, when observing the pattern from above, the distance from the center to the edge of the pattern was measured at an arbitrary point, and the measurement variation was evaluated using 3σ. The results were evaluated according to the following criteria and used to evaluate the uniformity of the pattern width. The results are shown in Table 4.

[0215] AA:3σ was less than 1.5 nm. A: 3σ was greater than or equal to 1.5 nm and less than 1.8 nm. B: 3σ was 1.8 nm or more and less than 2.2 nm. C:3σ was 2.2 nm or more and less than 2.5 nm. D:3σ was greater than or equal to 2.5 nm and less than 2.8 nm. E:3σ was greater than or equal to 2.8 nm and less than 3.1 nm. F:3σ was 3.1 nm or more.

[0216] [Examples 2 to 21 and Examples 23 to 28] The performance of each chemical solution in suppressing residue defects, bridge defects, stain defects, and pattern width uniformity was evaluated in the same manner as above, except that chemical solutions 2 to 21 and chemical solutions 23 to 28 were used instead of chemical solution 1. The results are shown in Table 4.

[0217] [Comparative Examples 1 and 2] Residue defect suppression performance, bridge defect suppression performance, stain defect suppression performance, and pattern width uniformity performance were evaluated in the same manner as above, except that chemical solutions 29 and 30 were used instead of chemical solution 1. The results are shown in Table 4.

[0218] [Example 22] The performance of suppressing residue defects, suppressing bridge defects, suppressing stain defects, and uniformity of pattern width of chemical solution 22 were evaluated in the same manner as above, except that no pre-wet liquid was used and chemical solution 22 was used as the developer. The results are shown in Table 4.

[0219] [Table 5]

[0220] [Example 29] Resist composition 2, which is a chemical solution, was obtained using the same method and ingredients as for resist composition 1, except that 67.5 g of PGMEA and 75 g of EL in resist composition 1 were replaced with 67.5 g of PGMEA and 75 g of EL purified by the purification method for chemical solution 1 described in Example 1.

[0221] Next, for resist composition 2, the number of particles with diameters of 0.5 to 17 nm contained in the chemical solution was evaluated using the same method as above, and it was found to be approximately the same as in Example 1. In addition, a pattern was formed using the same method as in Example 1, except that resist composition 2 was used and no pre-wet liquid was used. The residue defect suppression performance, bridge defect suppression performance, pattern width uniformity performance, and stain defect suppression performance were investigated, and the results were similar to those of Example 1.

[0222] From the results in Table 4, it can be seen that the chemical solutions described in Examples 1 to 21 and Examples 23 to 28, when used as pre-wetting solutions, had excellent residue defect suppression performance, excellent bridge defect suppression performance, excellent pattern width uniformity performance, and excellent stain defect suppression performance. Furthermore, from the results of Table 4, it was found that the chemical solution described in Example 22, when used as a developer, had excellent residue defect suppression performance, excellent bridge defect suppression performance, excellent pattern width uniformity performance, and excellent stain defect suppression performance.

[0223] Furthermore, the chemical solution of Example 29, as a resist solution, had excellent performance in suppressing residue defects, excellent performance in suppressing bridge defects, excellent performance in uniformity of pattern width, and excellent performance in suppressing stain defects.

[0224] Chemical solution 1, which had a maximum particle size in the range of 0.5 nm or more and less than 5 nm, had better residue defect suppression performance, better bridge defect suppression performance, better pattern width uniformity performance, and better stain defect suppression performance than chemical solution 8. Furthermore, chemical solution 1 had even better bridge defect suppression performance than chemical solution 9.

[0225] Compared to chemical solution 10, chemical solution 1, in which A / (B+C) is less than 1.0, had better residue defect suppression performance, better bridge defect suppression performance, better pattern width uniformity performance, and better stain defect suppression performance.

[0226] A / (B+C) is 1.0×10 -1 Compared to chemical solution 12, chemical solution 1 below had better residue defect suppression performance, better bridge defect suppression performance, better pattern width uniformity performance, and better stain defect suppression performance.

[0227] U / V is 1.0×10 1 Compared to chemical solution 16, chemical solution 1 had better residue defect suppression performance, better bridge defect suppression performance, better pattern width uniformity performance, and better stain defect suppression performance.

[0228] Pb / Ti is 1.0×10 -3Chemical solution 1, which has a refractive index of ∼2.0, had better residue defect suppression performance, better bridge defect suppression performance, better pattern width uniformity performance, and better stain defect suppression performance than chemical solution 17 and chemical solution 20. [Explanation of symbols]

[0229] 10 Purification equipment 11 Production Tank 12(a), 12(b) Filter unit 13 Filling equipment 14 Conduit 15(a) Regulating valves 16 Filtration equipment

Claims

1. an organic solvent; metal-containing particles containing metal atoms measurable by an energy dispersive X-ray analyzer; A chemical solution containing Among the metal-containing particles, the number of metal nanoparticles having a particle diameter of 0.5 to 17 nm contained per unit volume of the chemical solution is 6.0×10 3 to 8.5×10 6 particles / cm ３ and the metal nanoparticles are at least one type selected from the group consisting of particles A consisting of a simple substance of the metal atom, particles B consisting of an oxide of the metal atom, and particles C consisting of a simple substance of the metal atom and an oxide of the metal atom; a ratio of the number of particles A contained per unit volume of the chemical solution to the total number of particles B contained and the number of particles C contained per unit volume of the chemical solution is 1.0 × 10 -1 or less; the organic solvent is selected from the group consisting of cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, n-butyl acetate, isoamyl acetate, methyl isobutyl carbinol, isopropanol, ethyl lactate, and propylene carbonate; It is applied to the resist process by exposure, A chemical solution used for pre-wetting. The particle size is determined by the following method 1 or method 2. Method 1: The chemical solution is applied to a silicon substrate to form a substrate with a chemical solution layer, the surface of the substrate with the chemical solution layer is scanned with a laser beam, scattered light is detected, particle diameters are identified, and elemental analysis is performed by energy dispersive X-ray analysis to identify the target particles. Method 2: A SiOx layer is formed on a substrate by a CVD method, then a chemical solution layer is formed using the chemical solution so as to cover the SiOx layer, then a composite layer having the SiOx layer and the chemical solution layer is dry-etched, the resulting protrusions are irradiated with light and scattered light is detected, the volume of the protrusions is calculated from the scattered light, the particle diameter of the particles is identified from the volume of the protrusions, and elemental analysis is performed by energy dispersive X-ray analysis to identify the target particles.

2. An organic solvent, metal-containing particles containing at least one metal atom selected from the group consisting of Fe atoms, Al atoms, Cr atoms, Ni atoms, Pb atoms, Zn atoms, and Ti atoms; A chemical solution containing Among the metal-containing particles, the number of metal nanoparticles having a particle diameter of 0.5 to 17 nm contained per unit volume of the chemical solution is 6.0×10 3 to 8.5×10 6 particles / cm 3 ; the metal nanoparticles are at least one type selected from the group consisting of particles A consisting of a simple substance of the metal atom, particles B consisting of an oxide of the metal atom, and particles C consisting of a simple substance of the metal atom and an oxide of the metal atom; a ratio of the number of particles A contained per unit volume of the chemical solution to the total number of particles B contained and the number of particles C contained per unit volume of the chemical solution is 1.0 × 10 -1 or less; the organic solvent is selected from the group consisting of cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, n-butyl acetate, isoamyl acetate, methyl isobutyl carbinol, isopropanol, ethyl lactate, and propylene carbonate; It is applied to the resist process by exposure, A chemical solution used for pre-wetting. The particle size is determined by the following method 1 or method 2. Method 1: The chemical solution is applied to a silicon substrate to form a substrate with a chemical solution layer, the surface of the substrate with the chemical solution layer is scanned with a laser beam, scattered light is detected, particle diameters are identified, and elemental analysis is performed by energy dispersive X-ray analysis to identify the target particles. Method 2: A SiOx layer is formed on a substrate by a CVD method, then a chemical solution layer is formed using the chemical solution so as to cover the SiOx layer, then a composite layer having the SiOx layer and the chemical solution layer is dry-etched, the resulting protrusions are irradiated with light and scattered light is detected, the volume of the protrusions is calculated from the scattered light, the particle diameter of the particles is identified from the volume of the protrusions, and elemental analysis is performed by energy dispersive X-ray analysis to identify the target particles.

3. An organic solvent, metal-containing particles containing at least one metal atom selected from the group consisting of Pb atoms and Ti atoms; A chemical solution containing Among the metal-containing particles, the number of metal nanoparticles having a particle diameter of 0.5 to 17 nm contained per unit volume of the chemical solution is 6.0×10 3 to 8.5×10 6 particles / cm 3 ; the metal nanoparticles are at least one type selected from the group consisting of particles A consisting of a simple substance of the metal atom, particles B consisting of an oxide of the metal atom, and particles C consisting of a simple substance of the metal atom and an oxide of the metal atom; a ratio of the number of particles A contained per unit volume of the chemical solution to the total number of particles B contained and the number of particles C contained per unit volume of the chemical solution is 1.0 × 10 -1 or less; the organic solvent is selected from the group consisting of cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, n-butyl acetate, isoamyl acetate, methyl isobutyl carbinol, isopropanol, ethyl lactate, and propylene carbonate; It is applied to the resist process by exposure, A chemical solution used for pre-wetting. The particle size is determined by the following method 1 or method 2. Method 1: The chemical solution is applied to a silicon substrate to form a substrate with a chemical solution layer, the surface of the substrate with the chemical solution layer is scanned with a laser beam, scattered light is detected, particle diameters are identified, and elemental analysis is performed by energy dispersive X-ray analysis to identify the target particles. Method 2: A SiOx layer is formed on a substrate by a CVD method, then a chemical solution layer is formed using the chemical solution so as to cover the SiOx layer, then a composite layer having the SiOx layer and the chemical solution layer is dry-etched, the resulting protrusions are irradiated with light and scattered light is detected, the volume of the protrusions is calculated from the scattered light, the particle diameter of the particles is identified from the volume of the protrusions, and elemental analysis is performed by energy dispersive X-ray analysis to identify the target particles.

4. 4. The chemical solution according to claim 1, wherein a particle size distribution based on the number of the metal-containing particles has a maximum value in at least one range selected from the group consisting of a particle size range of less than 5 nm and a particle size range of more than 17 nm.

5. The drug solution according to claim 4 , wherein the particle size distribution has a maximum value in a particle size range of 0.5 nm or more and less than 5 nm.

6. The chemical solution according to any one of claims 1 to 5, which is used in the manufacture of semiconductor devices.

7. The chemical solution according to any one of claims 1 to 6, further comprising an organic compound having a boiling point of 300°C or higher.

8. The chemical solution according to any one of claims 1 to 7, wherein the metal nanoparticles contain at least one selected from the group consisting of metal nanoparticles containing Pb atoms and metal nanoparticles containing Ti atoms.

9. 9. The chemical solution according to claim 1, wherein the metal nanoparticles contain metal nanoparticles containing Pb atoms and metal nanoparticles containing Ti atoms.

10. The ratio of the number of metal nanoparticles containing Pb atoms to the number of metal nanoparticles containing Ti atoms per unit volume of the chemical solution is 1.0 × 10 －３ The drug solution according to any one of claims 1 to 9, wherein the viscosity is 2.0 or less.

11. A method for producing the chemical solution according to any one of claims 1 to 10, comprising a filtration step of filtering a material to be purified containing an organic solvent using a filter to obtain the chemical solution.

12. 12. The method for producing a chemical solution according to claim 11, wherein the filtration step is a multistage filtration step in which the product to be purified is passed through two or more types of filters that differ in at least one property selected from the group consisting of filter material, pore size, and pore structure.

13. 13. The method for producing a chemical solution according to claim 11 or 12, wherein, when one filter is used, the pore diameter of the filter is 5 nm or less, and when two or more filters are used, the pore diameter of the filter having the smallest pore diameter among the filters is 5 nm or less.

Images