Drug solution, and method for manufacturing the drug solution

Abstract

The present invention aims to provide a chemical solution that exhibits excellent defect suppression performance even when applied to a resist process using EUV exposure. It also aims to provide a method for producing the chemical solution. [Solution] The present invention provides a chemical solution containing an organic solvent and metal-containing particles containing metal atoms, wherein the number of metal nanoparticles with a particle diameter of 0.5 to 17 nm per unit volume of the chemical solution is 1.0 × 10 1 ~1.0×10 9 pieces / cm 3 That is the case.

Description

[Technical Field]

[0001] This invention relates to a drug solution and a method for producing a drug solution. [Background technology]

[0002] In the manufacturing of semiconductor devices by wiring formation processes including photolithography, chemical solutions containing water and / or organic solvents are used as pre-wetting solutions, resist solutions (resist compositions), developers, rinse solutions, stripping solutions, chemical mechanical polishing (CMP) slurries, and post-CMP cleaning solutions, or as diluents thereof. In recent years, advances in photolithography technology have led to the miniaturization of patterns. One method used to miniaturize patterns is to shorten the wavelength of the exposure light source. Instead of conventionally used exposure light sources such as ultraviolet light, KrF excimer lasers, and ArF excimer lasers, attempts are being made to form patterns using even shorter wavelengths such as EUV (extreme ultraviolet). The pattern formation processes described above using EUV and other methods are being developed with a target resist pattern width of 10-15 nm, and the chemicals used in these processes require even greater defect suppression capabilities.

[0003] Regarding conventional methods for manufacturing chemical solutions used in resist pattern formation, Patent Document 1 describes a method for manufacturing a resist composition used in the semiconductor device manufacturing process, comprising cleaning a resist composition manufacturing apparatus with a cleaning solution, removing the cleaning solution from the manufacturing apparatus and rotating it onto an evaluation substrate, and determining that the change in defect density for defects of size 100 nm or larger on the evaluation substrate before and after coating is 0.2 defects / cm². 2 A method for producing a resist composition is described, characterized by washing until the following conditions are met, and then producing the resist composition using a manufacturing apparatus. The above document states that when ArF exposure was performed using a chemical solution (resist composition) produced by this method, pattern defects and the like were suppressed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-049395 [Overview of the project] [Problems that the invention aims to solve]

[0005] The inventors of the present invention have found that when a pattern is formed by EUV exposure using a resist composition containing the chemical solution produced by the above manufacturing method, defects occur. Therefore, the object of the present invention is to provide a chemical solution that is less prone to generating defects when applied to a resist process by EUV exposure, in other words, a chemical solution that has excellent defect suppression performance when applied to a resist process by EUV exposure. Furthermore, the present invention also aims to provide a method for producing a drug solution. [Means for solving the problem]

[0006] As a result of diligent research to solve the above problems, the 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 number of metal nanoparticles with a particle diameter of 0.5 to 17 nm per unit volume of the chemical solution is 1.0 × 10 1 ~1.0×10 9 pieces / cm 3 It is a chemical solution. [2] The drug 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 size less than 5 nm and a range of particle size 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 size of 0.5 nm or more and less than 5 nm. [4] A chemical solution described in any of [1] to [3] used in the manufacture of semiconductor devices. [5] The drug solution according to any one of [1] to [4], wherein the metal nanoparticles consist of at least one selected from the group consisting of particles A consisting of elemental metal atoms, particles B consisting of oxides of metal atoms, and particles C consisting of elemental metal atoms and oxides of metal atoms. [6] The drug solution according to [5], wherein the ratio of the number of particles A to the sum of the number of particles B and C per unit volume of the drug solution is less than 1.0. [7] The number ratio of contained particles is 1.0 × 10 -1 The drug solution described in [5] or [6] below. [8] Furthermore, the chemical solution according to any one of [1] to [7] contains an organic compound having a boiling point of 300°C or higher. [9] The drug solution according to [8], wherein at least a portion of the metal nanoparticles is particle U containing an organic compound.

[10] At least a portion of the metal nanoparticles are particles U containing an organic compound and particles V not containing an organic compound, and the ratio of the number of particles U to the number of particles V per unit volume of the drug solution is 1.0 × 10 1 The above is the drug solution described in [8] or [9].

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

[10] , 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.

[12] A drug solution according to any one of [1] to

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

[13] The ratio of the number of Pb-containing metal nanoparticles to the number of Ti-containing metal nanoparticles per unit volume of the drug solution is 1.0 × 10 -3 A drug solution described in any of [1] to

[12] , with a value of ~2.0.

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

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

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

[14] , wherein the filtration step is a multi-stage filtration step in which the crude product is passed through two or more filters, at least one of which is different in terms of the filter material, pore diameter, and pore structure.

[16] The method for producing a chemical 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 having the smallest pore diameter among the filters is 5 nm or less. [Effect of the Invention]

[0008] According to the present invention, it is possible to provide a chemical solution having excellent defect suppression performance even when applied to a resist process using EUV exposure. Further, the present invention can provide a method for producing a chemical solution. [Brief Description of the Drawings]

[0009] [Figure 1] It is a schematic diagram showing a typical example of a purification apparatus capable of performing a multi-stage filtration step. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In the present invention, "ppm" means "parts-per-million (10 -6 )", "ppb" means "parts-per-billion (10 -9 )", "ppt" means "parts-per-trillion (per trillion (10 -12 )", and "ppq" means "parts-per-quadrillion (10 -15 )". Furthermore, in the notation of groups (atomic groups) in this invention, the notation that does not specify substitution or unsubstituted includes both substituted and unsubstituted groups, to the extent that it does not impair the effects of the present invention. For example, "hydrocarbon group" includes not only unsubstituted hydrocarbon groups but also substituted hydrocarbon groups. The same applies to each compound. Furthermore, in this invention, "radiation" means, for example, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, or electron beams. Also, in this invention, "light" means active light or radiation. In this invention, unless otherwise specified, "exposure" includes not only exposure with far ultraviolet light, X-rays, or EUV, but also drawing with particle beams such as electron beams or ion beams.

[0011] [Medicinal solution] A 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, wherein the number of metal nanoparticles with a particle diameter of 0.5 to 17 nm in the chemical solution is 1.0 × 10⁻¹⁶ 1 ~1.0×10 9 pieces / cm 3 It is a chemical solution. The mechanism by which this drug solution solves the above problems is not entirely clear, but the inventors speculate on the mechanism as follows. Note that the following mechanism is speculative, and even if the effects of the present invention are obtained by a different mechanism, it is still within the scope of the present invention.

[0012] This drug solution contains metal nanoparticles with a particle size of 0.5 to 17 nm, with a total particle count of 1.0 × 10⁻⁶ 1 ~1.0×10 9 pieces / cm 3 One of its distinguishing features is that it was controlled to that extent. In processes where EUV exposure is applied, it is required to reduce the pattern spacing, pattern width, and the pitch of the pattern (the sum of the width and spacing of a single pattern when these are arranged periodically), as well as the spacing, width, and pitch of the wiring produced (the sum of the width and spacing of a single wiring when these are arranged periodically). Specifically, the pattern width and / or pattern spacing are often around 10-15 nm (in this case, the pattern pitch is often 20-30 nm). In such cases, the inventors have found that it is necessary to control even finer particles on a number-by-number basis, which was not much of a problem in conventional processes.

[0013] Of the particles mentioned above, metal-containing particles with a particle diameter of less than 0.5 nm tend to aggregate more easily, often forming coarser particles. Therefore, they are often removed during the process (for example, by being washed away), and it is presumed that their impact on the defect suppression performance of the chemical solution is not very significant. On the other hand, metal-containing particles with a particle diameter exceeding 17 nm are sufficiently large compared to the required resist pitch, and are therefore often removed during the process, similar to the above, and are presumed to have little impact on the defect suppression performance of the chemical solution.

[0014] It is presumed that metal nanoparticles with a particle size of 0.5 to 17 nm tend to be more difficult to remove from the substrate. The number of metal nanoparticles contained per unit volume of the chemical solution is 1.0 × 10⁻⁶. 1 pieces / cm 3 As a result, metal nanoparticles tend to aggregate easily and are more readily removed during the process, and it is presumed that the chemical solution will have excellent defect suppression performance. On the other hand, the number of metal nanoparticles contained per unit volume of the drug solution is 1.0 × 10⁻⁶ 9 pieces / cm 3 The following conditions are met: the metal nanoparticles themselves are suppressed from causing defects, and as a result, the chemical solution is presumed to have excellent defect suppression performance. The amount of metal nanoparticles in the drug solution can be measured by the method described in the examples, and the number of metal nanoparticles per unit volume of the drug solution is rounded to two significant figures.

[0015] [Organic solvents] The chemical solution contains an organic solvent. While there are no particular restrictions on the content of the organic solvent in the chemical solution, it is generally preferable to have 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 preferable 99.99% by mass or more, relative to the total mass of the chemical solution. There are no particular upper limits, but it is often less than 100% by mass. Organic solvents may be used individually or in combination of two or more. When using two or more organic solvents in combination, it is preferable that their total content be within the above range.

[0016] In this specification, an 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 above-mentioned 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 above-mentioned chemical solution is considered an organic solvent. In this specification, "liquid" means that the substance is in a liquid state at 25°C and atmospheric pressure.

[0017] The type of organic solvent is not particularly limited, and known organic solvents can be used. Examples of organic solvents include alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate, alkyl alkoxypropionate, cyclic lactone (preferably having 4 to 10 carbon atoms), monoketone compounds which may have a ring (preferably having 4 to 10 carbon atoms), alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate. Furthermore, as organic solvents, for example, those described in Japanese Patent Publication No. 2016-057614, Japanese Patent Publication No. 2014-219664, Japanese Patent Publication No. 2016-138219, and Japanese Patent Publication No. 2015-135379 may be used.

[0018] As the organic solvent, 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 is preferred. Among these, CHN, PGMEA, PGME, nBA, PC, and mixtures thereof are preferred in that they yield a chemical solution with superior effects according to the present invention. Furthermore, organic solvents may be used individually or in combination of two or more types. The type and content of organic solvents in the chemical solution can be measured using a gas chromatograph-mass spectrometer.

[0019] [Metal-containing particles] This drug solution contains metal-containing particles that contain metal atoms. The preferred method for manufacturing this chemical solution will be described later, but generally, this chemical solution can be manufactured by purifying a material containing the organic solvent and impurities already described. Metal-containing particles may be intentionally added during the manufacturing process of the chemical solution, may be originally contained in the material to be purified, or may be transferred (so-called contamination) from the chemical solution manufacturing equipment during the manufacturing process of the chemical solution.

[0020] While there are no particular limitations on the metal atoms, examples include Fe atoms, Al atoms, Cr atoms, Ni atoms, Pb atoms, Zn atoms, and Ti atoms. In particular, strictly controlling the content of metal-containing particles in the chemical solution that contain at least one selected from the group consisting of Fe atoms, Al atoms, Pb atoms, Zn atoms, and Ti atoms tends to yield better defect suppression performance, and strictly controlling the content of metal-containing particles in the chemical solution that contain at least one selected from the group consisting of Pb atoms and Ti atoms tends to yield even better defect suppression performance. In other words, 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, 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 particles contain either Pb atoms or Ti atoms. Furthermore, the metal-containing particles may contain one type of metal atom alone, or two or more types in combination.

[0021] There are no particular restrictions on the particle size of metal-containing particles, but for example, in chemical solutions used for semiconductor device manufacturing, the content of particles with a particle size of approximately 0.1 to 100 nm in the chemical solution is often the target of control. In particular, the inventors' research has shown that, especially in chemical solutions applied to EUV lithography photoresist processes, controlling the content of metal-containing particles (hereinafter also referred to as "metal nanoparticles") with a particle size of 0.5 to 17 nm in the chemical solution makes it easier to obtain a chemical solution with excellent defect suppression performance. As already explained, in EUV lithography photoresist processes, fine resist spacing, resist width, and resist pitch are often required. In such cases, it is necessary to control even finer particles on a number-by-number basis, which was not much of a problem in conventional processes.

[0022] While there are no particular limitations on the particle size distribution based on the number of metal-containing particles, it is preferable to have a maximum value in at least one of the ranges selected from the group consisting of particle size less than 5 nm and particle size greater than 17 nm, in order to obtain a drug solution that exhibits superior effects of the present invention. In other words, it is preferable that the particle size 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 superior defect suppression performance, in particular, superior 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 with even better effects of the present invention, it is even more preferable that the particle size distribution based on the number of particles has a maximum value in the range of particle size between 0.5 nm and less than 5 nm. As a result, the chemical solution has an even better ability to suppress bridge defects.

[0023] <Metal nanoparticles> Metal nanoparticles refer to metal-containing particles with a particle size of 0.5 to 17 nm. The number of metal nanoparticles per unit volume of the drug solution is 1.0 × 10⁻⁶ 1 ~1.0×10 9 pieces / cm 3 Therefore, in terms of having a superior effect of the present invention, the number of particles contained is 1.0 × 10 2 pieces / cm 3 The above is preferable, 1.0 × 10 3 pieces / cm 3 The above is more preferable, 1.0 × 10 6 pieces / cm 3 The following is preferable: 1.0 × 10 5 pieces / cm 3 The following is more preferable: 1. × 10 4 pieces / cm 3 The following is even more preferable. The number of metal nanoparticles contained per unit volume of the drug solution is 1.0 × 10⁻⁶ 2 ~1.0×10 6 pieces / cm 3 Therefore, the chemical solution has superior defect suppression performance.

[0024] The metal atoms contained in the metal nanoparticles are not particularly limited, but are the same as those described earlier for metal atoms contained in metal-containing particles. In particular, in order to obtain a drug solution having a better effect of the present invention, at least one selected from the group consisting of Pb atoms and Ti atoms is preferred as the metal atom, and it is more preferable for the metal nanoparticles to contain both Pb atoms and Ti atoms. In other words, it is preferable for the metal nanoparticles to 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 for them to contain both Pb nanoparticles and Ti nanoparticles. A typical example of metal nanoparticles containing both Pb and Ti atoms is a form in which the drug solution contains both Pb-containing metal nanoparticles and Ti-containing metal nanoparticles.

[0025] The particle number ratio (Pb / Ti) of Pb nanoparticles and Ti nanoparticles in the drug solution is not particularly limited, but generally it is 1.0 × 10⁻⁶. -4 ~3.0 is preferred, and 1.0 × 10 -3 ~2.0 is more preferable, 1.0 × 10 -2 ~1.5 is even more preferable. Pb / Ti is 1.0 × 10 -3 When the value is ~2.0, the chemical solution exhibits superior effects of the present invention, particularly superior bridge defect suppression performance. The inventors have found that Pb nanoparticles and Ti nanoparticles tend to associate with each other, for example, when a chemical solution is applied to a wafer, and are likely to cause defects (particularly bridge defects) during the development of the resist film. Pb / Ti is 1.0 × 10 -3 Surprisingly, when the ratio is ~2.0, the occurrence of defects is more easily suppressed. In this specification, Pb / Ti, A / (B+C) and U / V (described later) are rounded to two significant figures.

[0026] Metal nanoparticles only need to contain metal atoms, and their form is not particularly limited. Examples include individual metal atoms, compounds containing metal atoms (hereinafter also referred to as "metal compounds"), and composites thereof. Furthermore, metal nanoparticles may contain multiple metal atoms. When metal nanoparticles contain multiple metals, the metal atom with the highest content (atm%) among the multiple metals is considered the main component. Therefore, when referring to Pb nanoparticles, if multiple metals are present, it means that Pb atoms are the main component among the multiple metals.

[0027] The composite is not particularly limited, but examples include so-called core-shell type particles having a single metal atom and a metal compound covering at least a portion of the single metal atom, solid solution particles containing metal atoms and other atoms, eutectic particles containing metal atoms and other atoms, aggregate particles of single metal atoms and metal compounds, 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 metal atoms contained in the metal compound are not particularly limited, but examples include carbon atoms, oxygen atoms, nitrogen atoms, hydrogen atoms, sulfur atoms, and phosphorus atoms, with oxygen atoms being preferred. The form in which the metal compound contains oxygen atoms is not particularly limited, but oxides of metal atoms are more preferred.

[0029] In order to obtain a drug solution having a superior effect of the present invention, it is preferable that the metal nanoparticles consist of at least one selected from the group consisting of particles made of elemental metal atoms (particle A), particles made of oxides of metal atoms (particle B), and particles made of elemental metal atoms and oxides of metal atoms (particle C). While there are no particular limitations on the relationship between the number of particles A, B, and C contained in the number of metal nanoparticles per unit volume of the drug solution, in order to obtain a drug solution with superior effects of the present invention, the ratio of the number of particles A to the sum of the number of particles B and C (hereinafter also referred to as "A / (B+C)") is preferably 1.5 or less, more preferably less than 1.0, and 2.0 × 10⁻⁶. -1 The following is even more preferable: 1.0 × 10 -1 The following are particularly preferred: 1.0 × 10 -3 The above is preferable, 1.0 × 10 -2 The above is preferable. When A / (B+C) is less than 1.0, the chemical solution exhibits superior bridge defect suppression performance, superior pattern width uniformity performance, and stain defect suppression performance. Also, A / (B+C) is 0.1 (1.0 × 10 -1 If the value is below this, the chemical solution will have superior residue defect suppression performance.

[0030] [Other ingredients] The chemical solution may contain other components besides those mentioned above. Examples of other components include organic compounds other than organic solvents (especially 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 organic compounds other than organic solvents (hereinafter also referred to as "specified organic compounds"). In this specification, a specified organic compound means an organic compound different from the organic solvent contained in the chemical solution, and which 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 contained in an amount of 10,000 ppm by mass or less relative to the total mass of the chemical solution is considered a specified organic compound and not an organic solvent. Furthermore, if multiple types of organic compounds are contained in the chemical solution, and each organic compound is present in an amount of 10,000 ppm by mass or less as described above, then each of them will be considered a specific organic compound.

[0032] Specific organic compounds may be added to the chemical solution, or they may be unintentionally mixed in 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, cases in which the specific organic compound is contained in the raw materials used in the manufacture of the chemical solution (e.g., organic solvents), or is mixed in during the manufacturing process of the chemical solution (e.g., contamination).

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

[0034] While there are no particular restrictions on the number of carbon atoms in the specific organic compound, a number of 8 or more is preferred, and 12 or more is more preferred, in that the chemical solution exhibits superior effects of the present invention. Furthermore, while there are no particular restrictions on the upper limit of the number of carbon atoms, 30 or less is preferred.

[0035] Examples of specific organic compounds include by-products generated during the synthesis of organic solvents, and / or unreacted raw materials (hereinafter also referred to as "by-products, etc."). Examples of the above-mentioned by-products include compounds represented by the following formulas I to V.

[0036] [ka]

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

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

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

[0040] Furthermore, it is preferable that R1 and R2 satisfy the relationship 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. However, R3 and R4 cannot both be hydrogen atoms.

[0042] The alkyl groups represented by R3 and R4 are preferably alkyl groups having 1 to 12 carbon atoms, and more preferably alkyl groups having 1 to 8 carbon atoms.

[0043] The alkenyl groups represented by R3 and R4 are preferably alkenyl groups having 2 to 12 carbon atoms, and more preferably alkenyl groups having 2 to 8 carbon atoms.

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

[0045] The cycloalkenyl groups represented by R3 and R4 are preferably cycloalkenyl groups having 3 to 12 carbon atoms, and more preferably cycloalkenyl groups having 6 to 8 carbon atoms.

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

[0047] Furthermore, it is preferable that R3 and R4 satisfy the relationship that the compound represented by formula II has 8 or more carbon atoms.

[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 described above may have an ether linkage in its chain, and may also have substituents such as a hydroxyl 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 they are bonded to each other to form a ring.

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

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

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

[0055] Furthermore, it is preferable that R6 and R7 satisfy the relationship that the compound represented by formula IV has 8 or more carbon atoms.

[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. L represents a single bond or an alkylene group.

[0057] The alkyl groups represented by R8 and R9 are preferably alkyl groups having 6 to 12 carbon atoms, and more preferably alkyl groups having 6 to 10 carbon atoms.

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

[0059] The ring formed by the bonding of R8 and R9 is a cyclic diketone structure. This cyclic diketone structure 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 preferably an alkylene group having 1 to 12 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms. Furthermore, R8, R9, and L satisfy the condition that the compound represented by formula V has 8 or more carbon atoms. While not particularly limited, if the organic solvent is an amide compound, imide compound, or sulfoxide compound, then in one form, examples include amide compounds, imide compounds, and sulfoxide compounds having 6 or more carbon atoms. Furthermore, specific organic compounds include, for example, the following compounds.

[0061] [ka]

[0062] [ka]

[0063] Furthermore, specific organic compounds include dibutylhydroxytoluene (BHT), distearylthiodipropionate (DSTP), 4,4'-butylidenebis-(6-t-butyl-3-methylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), and antioxidants such as those described in Japanese Patent Publication No. 2015-200775; unreacted raw materials; structural isomers and by-products generated during the production of organic solvents; and elutes from components of organic solvent production equipment (for example, plasticizers eluted 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), and 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 ester, benzoic acid ester, terephthalate (e.g., dioctyl terephthalate (DEHT)), 1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH), epoxidized vegetable oil, sulfonamide (e.g., N-(2-hydroxypropyl)benzenesulfonamide (HP) Examples include BSA, N-(n-butyl)benzenesulfonamide (BBSA-NBBS), organophosphate esters (e.g., tricresyl phosphate (TCP), tributyl phosphate (TBP)), acetylated monoglycerides, triethyl citrate (TEC), triethyl acetyl citrate (ATEC), tributyl citrate (TBC), tributyl acetyl citrate (ATBC), trioctyl citrate (TOC), trioctyl acetyl citrate (ATOC), trihexyl citrate (THC), trihexyl acetyl citrate (ATHC), epoxidized soybean oil, ethylene propylene rubber, polybutene, addition polymers of 5-ethylidene-2-norbornene, and polymeric plasticizers as exemplified below. These specific organic compounds are presumed to be introduced into the purified product or chemical solution from filters, pipes, tanks, O-rings, and containers that come into contact with the product 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 organic compounds with a boiling point of 300°C or higher (high-boiling point organic compounds) among the specified organic compounds. When the chemical solution contains organic compounds with a boiling point of 300°C or higher, they have a high boiling point and are less likely 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 point organic compounds in the chemical solution. Examples of such high-boiling-point organic compounds include dioctyl phthalate (boiling point 385°C), diisononyl phthalate (boiling point 403°C), dioctyl adipicate (boiling point 335°C), dibutyl phthalate (boiling point 340°C), and ethylene propylene rubber (boiling point 300-450°C).

[0067] The inventors have found that high-boiling-point organic compounds can exist in various forms when contained in a chemical solution. Examples of forms in which high-boiling-point organic compounds exist in a chemical solution include: particles formed by the aggregation of particles consisting of metal atoms or metal compounds and high-boiling-point organic compound particles; particles having particles consisting of metal atoms or metal compounds and high-boiling-point organic compounds arranged to cover at least a portion of the above particles; and particles formed by the coordination bonding of metal atoms and high-boiling-point organic compounds.

[0068] In particular, metal nanoparticles (particle U) containing organic compounds (preferably high-boiling point organic compounds) have a significant impact on the defect suppression performance of the chemical solution. The inventors have found that controlling the number of particles U per unit volume of the chemical solution dramatically improves the defect suppression performance of the chemical solution. Although the reason is not entirely clear, particle U tends to have a relatively lower surface free energy compared to metal nanoparticles (particle V) that do not contain organic compounds (preferably high-boiling point organic compounds). Such particle U is less likely to remain on the substrate treated with the chemical solution, and even if it does remain, it is easily removed when it comes into contact with the chemical solution again. For example, when the chemical solution is used as a developer and rinse solution, particle U is even less likely to remain on the substrate during development, and is even easier to remove by rinsing. In other words, as a result, both organic compounds (preferably high-boiling point organic compounds) and particles containing metal atoms are easier to remove. Furthermore, since resist films are generally water-repellent, it is presumed that particles U, which have lower surface energy, are less likely to remain on the substrate.

[0069] In terms of the ratio of the number of particles U to the number of particles V per unit volume of the drug solution, a drug solution exhibiting the superior effects of the present invention can be obtained, which is 10 (1.0 × 10). 1 ) Preferably 1.0 × 10 2 The following are preferred, more preferably 50 or less, even more preferably 35 or less, and particularly preferred 25 or less.

[0070] <Water> The above chemical solution may contain water. The type of water is not particularly limited; for example, distilled water, deionized water, and pure water can be used. Note that water is not included in the above organic impurities. Water may be added to the chemical solution, or it may be unintentionally mixed into the chemical solution during the manufacturing process. Examples of unintentional mixing during the manufacturing process include, but are not limited to, cases where water is contained in the raw materials used in the manufacture of the chemical solution (e.g., organic solvents), or where it is mixed during the manufacturing process (e.g., contamination).

[0071] The water content in the above-mentioned chemical solution is not particularly limited, but generally, 0.05 to 2.0% by mass of the total mass of the chemical solution is preferred. The water content in the chemical solution refers to the water content measured using an apparatus that uses the Karl Fischer moisture metering method as its measurement principle.

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

[0073] In acid-degradable groups, the polar group is protected by a group that is eliminated by acid (an acid-leaving group). Examples of acid-leaving groups include -C(R 36 )(R 37 )(R 38 ), -C(R 36 )(R 37 )(OR 39 ), and -C(R 01 )(R 02 )(OR 39 Examples include:

[0074] In the formula, R 36 ~R 39 Each of these independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. 36 and R 37 These elements may be joined together to form a ring.

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

[0076] The following details resin P, whose solubility in developing solutions primarily composed of organic solvents decreases due to the action of acid.

[0077] (Formula (AI): Repeating unit having an acid-degradable group) The resin P preferably contains repeating units represented by formula (AI).

[0078] [ka]

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

[0080] Examples of alkyl groups that may have substituents, represented by Xa1, include a methyl group and -CH2-R 11 The group represented by R is an example. 11 This 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 divalent linking groups for T include alkylene groups, -COO-Rt- groups, and -O-Rt- groups. In the formula, 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, and more preferably a -CH2- group, a -(CH2)2- group, or a -(CH2)3- group.

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

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

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

[0085] The repeating unit represented by formula (AI) preferably has, for example, Ra1 being a methyl group or an ethyl group, and Ra2 and Ra3 being bonded to form the aforementioned cycloalkyl group.

[0086] Each of the above groups may have substituents, and examples of substituents include alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbon atoms), with a preferred number of carbon atoms being 8 or less.

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

[0088] (Repeating units with a lactone structure) Furthermore, it is preferable that the resin P contains repeating units Q having a lactone structure.

[0089] The repeating unit Q having a lactone structure preferably has a lactone structure in its 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 types, but it is preferable to use it alone. The content of repeating units Q having a lactone structure is preferably 3 to 80 mol%, and more preferably 3 to 60 mol%, relative to the total number of repeating units in resin P.

[0090] As for the lactone structure, a lactone structure with 5 to 7 members is preferred, and a structure in which other ring structures are fused to the 5 to 7 member lactone structure in the form of a bicyclo or spiro structure is more preferred. The lactone structure is preferably a repeating unit having a lactone structure represented by any of the following formulas (LC1-1) to (LC1-17). The lactone structure is preferably represented by formula (LC1-1), formula (LC1-4), formula (LC1-5), or formula (LC1-8), and more preferably by formula (LC1-4).

[0091] [ka]

[0092] The lactone structure may have substituents (Rb2). Preferred substituents (Rb2) include C1-C8 alkyl groups, C4-C7 cycloalkyl groups, C1-C8 alkoxy groups, C2-C8 alkoxycarbonyl groups, carboxyl groups, halogen atoms, hydroxyl groups, cyano groups, and acid-degradable groups. n2 represents an integer from 0 to 4. When n2 is 2 or greater, the multiple substituents (Rb2) may be the same or different, and the multiple substituents (Rb2) may bond to each other to form a ring.

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

[0094] [ka]

[0095] During the ceremony, R 41 , R 42 and R 43 Each of these independently represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. However, R 42 It may also 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 another element to form a ring, it represents an (n+2) valent aromatic ring group. n represents an integer between 1 and 5.

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

[0098] R in general formula (I) 41 , R 42 and R 43 The cycloalkyl group may be monocyclic or polycyclic. Preferably, the cycloalkyl group is 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 substituents.

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

[0100] R in general formula (I) 41 , R 42 and R 43 The alkyl group included in the alkoxycarbonyl group is the above R 41 , R 42 and R 43 A alkyl group similar to the one in the example is preferred.

[0101] Examples of substituents on each of the above groups include alkyl groups, cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, cyano groups, and nitro groups, 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, for example, an arylene group having 6 to 18 carbon atoms such as a phenylene group, a tolylene group, a naphthylene group, and an anthracenylene group, and an aromatic ring group 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 more include a group formed by removing (n - 1) arbitrary 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 in the general formula (I) 41 , R 42 and R 43 mentioned alkyl groups; alkoxy groups such as methoxy group, ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group, and butoxy group; aryl groups such as phenyl group.

[0105] The alkyl group of -CONR 64 -(R 64 represents a hydrogen atom or an alkyl group.) represented by X4 includes 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, and a dodecyl group, which may have a substituent, and an alkyl group having 8 or less carbon atoms is more preferable.

[0106] As X4, a single bond, -COO- or -CONH- is preferable, and a single bond or -COO- is more preferable.

[0107] ​​In L4, the alkylene group is preferably a C1-C8 alkylene group such as a methylene group, ethylene group, propylene group, butylene group, hexylene group, or octylene group, which may have substituents.

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

[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 phenolic hydroxyl groups is preferably 0 to 50 mol%, more preferably 0 to 45 mol%, and even more preferably 0 to 40 mol%, relative to the total repeating units in resin P.

[0111] (Repeating units containing organic groups with polar groups) The resin P may further contain repeating units containing an organic group having a polar group, in particular repeating units having an alicyclic hydrocarbon structure substituted with a polar group. This improves substrate adhesion and developer affinity. Preferred alicyclic hydrocarbon structures substituted with polar groups include adamantyl groups, diamantyl groups, or norbornane groups. Preferred polar groups are hydroxyl groups or cyano groups.

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

[0113] (The repeating unit represented by general formula (VI)) The resin P may contain repeating units represented by the following general formula (VI).

[0114] [Chemical formula]

[0115] In the 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. However, R 62 may be bonded to Ar6 to form a ring, and in that case, R 62 represents a single bond or an alkylene group. X6 represents a single bond, -COO-, or -CONR 64 -. 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, and when bonded to R<( 62 to form a ring, it represents an (n + 2)-valent aromatic ring group. When n ≥ 2, Y2 each independently represents a hydrogen atom or a group that can be eliminated by the action of an acid. However, at least one of Y2 represents a group that can be eliminated by the action of an acid. n represents an integer from 1 to 4.

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

[0117] [Chemical formula]

[0118] L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group combining an alkylene group and 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 joined to form a ring (preferably a 5-membered or 6-membered ring).

[0119] The repeating unit represented by the above general formula (VI) is preferably the 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, alkyl group, cycloalkyl group, aryl group, aralkyl group, alkoxy group, acyl group, or heterocyclic group. M3 represents a single bond or a divalent linking group. Q3 represents an alkyl group, cycloalkyl group, aryl group, or heterocyclic group. Q3, M3, and at least two of R3 may be bonded together to form a ring.

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

[0123] (A repeating unit having silicon atoms in its side chains) The resin P may further contain repeating units having silicon atoms in their side chains. Examples of repeating units having silicon atoms in their side chains include (meth)acrylate repeating units having silicon atoms and vinyl repeating units having silicon atoms. A repeating unit having silicon atoms in its side chain is typically a repeating unit having a group having silicon atoms in its side chain. Examples of groups having silicon atoms include trimethylsilyl group, triethylsilyl group, triphenylsilyl group, tricyclohexylsilyl group, tritrimethylsiloxysilyl group, tritrimethylsilylsilyl group, methylbistrimethylsiloxysilyl group, methylbistrimethylsiloxysilyl group, dimethyltrimethylsiloxysilyl group, and cyclic or linear polysiloxanes, or cage-type, ladder-type, or random-type silsesquioxane structures as shown below. In the formula, R and R 1 Each of the symbols independently represents a monovalent substituent. * represents a bond.

[0124] [ka]

[0125] As repeating units having the above-mentioned group, for example, repeating units derived from acrylate compounds or methacrylate compounds having the above-mentioned group, or repeating units derived from compounds having the above-mentioned group and a vinyl group are preferred.

[0126] When the resin P has repeating units having silicon atoms in the side chains, the content is preferably 1 to 30 mol%, more preferably 5 to 25 mol%, and even more preferably 5 to 20 mol%, relative to the total repeating units in the resin P.

[0127] The weight-average molecular weight of resin P is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 5,000 to 15,000, as polystyrene equivalent values ​​determined by GPC (Gel permeation chromatography). By setting the weight-average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, as well as deterioration of developability and deterioration of film-forming properties due to increased viscosity.

[0128] The degree of dispersion (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 resin P is preferably 50 to 99.9% by mass, and more preferably 60 to 99.0% by mass, of the total solid content. Furthermore, in the chemical solution, resin P may be used alone or in combination of multiple types.

[0130] Other components contained in the chemical solution (e.g., acid generators, basic compounds, quenchers, hydrophobic resins, surfactants, and solvents) can all be those that are known. Examples of other components include those contained in photosensitive or radiation-sensitive resin compositions described in Japanese Patent Publication No. 2013-195844, Japanese Patent Publication No. 2016-057645, Japanese Patent Publication No. 2015-207006, International Publication No. 2014 / 148241, Japanese Patent Publication No. 2016-188385, and Japanese Patent Publication No. 2017-219818, etc.

[0131] [Uses of the chemical solution] The chemical solution according to the above embodiment is preferably used in the manufacture of semiconductor devices. In particular, it is more preferably used to form fine patterns with a node of 10 nm or less (for example, in a process including pattern formation using EUV). The chemical solution according to the above embodiment is more preferably used as a chemical solution (pre-wetting solution, developer, rinse solution, solvent for the resist solution, and stripping solution, 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, it is more preferably used for the manufacture of semiconductor devices manufactured using a resist film with a pattern width and / or pattern spacing of 17 nm or less.

[0132] Specifically, in semiconductor device manufacturing processes including lithography, etching, ion implantation, and stripping, it is used to treat organic matter after each process or before moving to the next process. Specifically, it is preferably used as a pre-wetting solution, developer, rinse solution, and stripping solution. For example, it can also be used to rinse the edge lines of semiconductor substrates before and after resist coating. Furthermore, the above chemical solution can also be used as a diluent for the resin contained in the resist solution, or as a solvent contained in the resist solution. It may also be diluted with other organic solvents and / or water.

[0133] Furthermore, the above chemical solution can be used for purposes other than the manufacture of semiconductor devices, and can also be used as a developer for polyimide, sensor resists, lens resists, etc., as well as a rinsing solution. Furthermore, the above-mentioned chemical solution can also be used as a solvent for medical or cleaning purposes. In particular, it can be suitably used for cleaning containers, piping, and substrates (e.g., wafers and glass).

[0134] In particular, this chemical solution exhibits superior effects when applied to pre-wetting solutions, developer solutions, and rinsing solutions in pattern formation using EUV (extreme ultraviolet) light.

[0135] [Method for manufacturing chemical solutions] The method for producing the above-mentioned chemical solution is not particularly limited, and known production methods can be used. In particular, in order to obtain a chemical solution having a more superior effect of the present invention, it is preferable that the method for producing the chemical solution includes a filtration step in which the substance to be purified containing an organic solvent is filtered using a filter to obtain the chemical solution.

[0136] The material to be purified used in the filtration process is procured by purchase or obtained by reacting raw materials. It is preferable to use a material with a low content of metal-containing particles and / or impurities, as previously described. Examples of commercially available materials of this type include those referred to as "high-purity grade products."

[0137] The method for reacting raw materials to obtain a product to be purified (typically a product containing an organic solvent) is not particularly limited, and known methods can be used. For example, one method involves reacting one or more raw materials in the presence of a catalyst to obtain an organic solvent. More specifically, examples include: a method of obtaining butyl acetate by reacting acetic acid and n-butanol in the presence of sulfuric acid; a method of obtaining 1-hexanol by reacting ethylene, oxygen, and water in the presence of Al(C2H5)3; a method of obtaining 4-methyl-2-pentanol by reacting cis-4-methyl-2-pentene in the presence of Ipc2BH (Diisopinocampheylborane); a method of obtaining PGMEA (propylene glycol 1-monomethyl ether 2-acetate) by reacting propylene oxide, methanol, and acetic acid in the presence of sulfuric acid; a method of obtaining IPA (isopropyl alcohol) by reacting acetone and hydrogen in the presence of copper oxide, zinc oxide, and aluminum oxide; a method of obtaining ethyl lactate by reacting lactic acid and ethanol; and so on.

[0138] <Filtration process> A method for producing a pharmaceutical solution according to an embodiment of the present invention includes a filtration step of filtering the substance to be purified using a filter to obtain a pharmaceutical solution. There are no particular limitations on the method of filtering the substance to be purified using a filter, but it is preferable to pass the substance to be purified through a filter unit having a housing and a cartridge filter housed in the housing, under or without pressure.

[0139] • Filter pore size There are no particular restrictions on the pore size of the filter, and filters with 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, especially preferably 5 nm or less, and most preferably 3 nm or less, as it allows for easy control of the number of particles with a particle size of 0.5 to 17 nm contained in the chemical solution within a desired range. There are no particular restrictions on the lower limit, 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 points of isopropanol (IPA) or HFE-7200 ("Novec 7200", manufactured by 3M, hydrofluoric acid ether, C4F9OC2H5).

[0140] A filter with a pore size of 5.0 nm or less is preferable because it allows for easier control of the number of particles with a particle size of 0.5 to 17 nm contained in the chemical solution. Hereinafter, filters with a pore size of 5 nm or less will also be referred to as "micropore filters." The micropore filter may be used alone or in combination with filters of other pore sizes. In particular, from the viewpoint of superior productivity, it is preferable to use it in combination with a filter with a larger pore size. In this case, clogging of the micropore filter can be prevented by passing the purified material, which has been filtered beforehand using a filter with a larger pore size, through the micropore filter. In other words, when using one filter, the pore size is preferably 5.0 nm or less, and when using two or more filters, the pore size of the filter with the smallest pore size is preferably 5.0 nm or less.

[0141] There are no particular limitations on the configuration in which two or more filters with different pore sizes are used sequentially, but one method is to arrange the filter units described above in order along the pipeline through which the substance to be purified is transported. In this case, if the flow rate of the substance to be purified per unit time is to be kept constant throughout the pipeline, the filter units with smaller pore sizes may experience greater pressure compared to the filter units with larger pore sizes. In this case, it is preferable to place pressure regulating valves and dampers between the filter units to keep the pressure on the filter units with smaller pore sizes constant, or to arrange filter units containing the same filters in parallel along the pipeline to increase the filtration area. By doing so, the number of particles of 0.5 to 17 nm contained in the chemical solution can be controlled more stably.

[0142] Filter materials The material of the filter is not particularly limited, and any known material can be used. Specifically, if it is a resin, examples include polyamides such as 6-nylon and 6,6-nylon; polyolefins such as polyethylene and polypropylene; polystyrene; polyimide; polyamide-imide; poly(meth)acrylate; polyfluorocarbons such as polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride; polyvinyl alcohol; polyester; cellulose; cellulose acetate, etc. Among these, at least one selected from the group consisting of nylon (6,6-nylon is preferred), polyolefin (polyethylene is preferred), poly(meth)acrylate, and polyfluorocarbon (polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA) are preferred) is preferred because it has better solvent resistance and the resulting chemical solution has better defect suppression performance. These polymers can be used individually or in combination of two or more. In addition to resin, diatomaceous earth and glass may also be used.

[0143] Furthermore, the filter may 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, plasma treatment, hydrophobic treatment, coating, gas treatment, and sintering.

[0144] Plasma treatment is preferred because it makes the filter surface hydrophilic. There are no particular limitations on the water contact angle on the surface of the filter that has been hydrophilicized by plasma treatment, but the static contact angle at 25°C measured with a contact angle meter is preferably 60° or less, more preferably 50° or less, and even more preferably 30° or less.

[0145] As for the chemical modification treatment, a method of introducing ion exchange groups into the substrate is preferred. In other words, as a filter, it is preferable to use one of the materials listed above as a base material and to introduce ion exchange groups into the base material. Typically, a filter containing a base material having ion exchange groups on its surface is preferred. The surface-modified base material is not particularly limited, but it is preferable to introduce ion exchange groups into the polymer mentioned above because it is easier to manufacture.

[0146] Examples of ion exchange groups include sulfonic acid groups, carboxyl groups, and phosphate groups as cation exchange groups, and quaternary ammonium groups as anion exchange groups. There are no particular limitations on the method of introducing ion exchange groups into a polymer, but a typical method involves grafting by reacting a compound having both an ion exchange group and a polymerizable group with the polymer.

[0147] There are no particular restrictions on the method of introducing ion exchange groups, but the resin fibers described above are irradiated with ionizing radiation (alpha rays, beta rays, gamma rays, X-rays, and electron beams, etc.) to generate active parts (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, a product is produced in which this monomer is bonded to the polyolefin fibers as graft polymerized side chains. By contacting the resin having these generated polymers as side chains with a compound having anion exchange groups or cation exchange groups, ion exchange groups are introduced into the graft polymerized side chain polymers to obtain the final product.

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

[0149] Using a filter with ion exchange groups makes it easier to control the content of metal atom-containing particles in the chemical solution within a desired range. The material of the filter with ion exchange groups is not particularly limited, but examples include polyfluorocarbons and polyolefins into which ion exchange groups have been introduced, with polyfluorocarbons into which ion exchange groups have been introduced being more preferred. The pore size of the filter having ion exchange groups is not particularly limited, but 1 to 30 nm is preferred, and 5 to 20 nm is more preferred. The filter having ion exchange groups may also serve as the filter having the smallest pore size as described above, or it may be used separately from the filter having the smallest pore size. In particular, in order to obtain a chemical solution with the superior effects of the present invention, the filtration step is preferably a configuration in which a filter having ion exchange groups and a filter without ion exchange groups but having the smallest pore size are used in combination. The material for the filter having the minimum pore size as described above is not particularly limited, but from the viewpoint of solvent resistance and other factors, at least one selected from the group consisting of polyfluorocarbon and polyolefin is generally preferred, and polyolefin is more preferred.

[0150] Furthermore, if the filter material is polyamide (especially nylon), the content of high-boiling point organic compounds and particle U in the chemical solution can be controlled more easily, and in particular, the content of particle U in the chemical solution can be controlled even more easily. Therefore, it is preferable to use two or more filters made of different materials 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 to which ion exchange groups have been introduced.

[0151] • Filter pore structure The pore structure of the filter is not particularly limited and can 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 pores in the filter, and the shape of the pores, etc., and is typically controllable by the filter manufacturing method. For example, porous films can be obtained by sintering powders such as resin, and fibrous films can be obtained by methods such as electrospinning, electroblowing, and meltblowing. These films each have different pore structures.

[0152] A "porous membrane" refers to a membrane that retains components in the material being purified, such as gels, particles, colloids, cells, and polyoligomers, but allows components substantially smaller than the pores to pass through. The retention of components in the material being purified by a porous membrane may depend on operating conditions, such as face velocity, use of surfactants, pH, and combinations thereof, and may also depend on the pore size and structure of the porous membrane, as well as the size and structure (hard particles or gel, etc.) of the particles to be removed.

[0153] When the purified product contains particulate matter U (which may be in gel form) as an impurity, particles containing high-boiling point organic compounds are often negatively charged, and polyamide filters function as non-sieving membranes to remove such particles. Typical non-sieving membranes include, but are not limited to, nylon membranes such as nylon-6 membranes and nylon-6,6 membranes. Furthermore, the term "non-sieve" retention mechanism used herein refers to retention resulting from the pressure drop of the filter or from mechanisms such as interference, diffusion, and adsorption, which are not related to the pore size.

[0154] Non-sieve retention includes retention mechanisms such as interference, diffusion, and adsorption that remove target particles from the purified material, regardless of the filter's pressure drop or pore size. Adsorption of particles to the filter surface can be mediated, for example, by intermolecular van der Waals forces and electrostatic forces. Interference occurs when particles moving through a non-sieve film layer with a meandering path cannot change direction quickly enough to avoid contact with the non-sieve film. Particle transport by diffusion mainly arises from the random motion or Brownian motion of small particles, creating a certain probability of collision between particles and the filter material. Non-sieve retention mechanisms can be active when there is no repulsive force between the particles and the filter.

[0155] UPE (ultra-high molecular weight polyethylene) filters are typically sieve membranes. A sieve membrane is a membrane that primarily captures particles via a sieve-holding mechanism, or a membrane optimized for capturing particles via a sieve-holding mechanism. Typical examples of sieving membranes include, but are not limited to, polytetrafluoroethylene (PTFE) membranes and UPE membranes. The "sieve retention mechanism" refers to the retention of particles that are to be removed because their size exceeds the pore diameter of the porous membrane. Sieve retention can be improved by forming a filter cake (an aggregation of particles to be removed on the membrane surface). The filter cake effectively functions as 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 film may also be poly(ethersulfone). When the fiber film is on the primary side of the porous film, it is preferable that the surface energy of the fiber film is higher than that of the polymer material of the porous film on the secondary side. An example of such a combination is when the material of the fiber film is nylon and the porous film is polyethylene (UPE).

[0157] The method for manufacturing the fiber film is not particularly limited, and known methods can be used. Examples of methods for manufacturing the fiber film include electrospinning, electroblowing, and meltblowing.

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

[0159] By using an asymmetric porous membrane and making the primary side a larger pore size, or in other words, making the primary side an open side, a pre-filtration effect can be produced.

[0160] The porous membrane may contain thermoplastic polymers such as PESU (polyethersulfone), PFA (perfluoroalkoxyalkane, a copolymer of tetrafluoroethylene and perfluoroalkoxyalkane), polyamide, and polyolefin, or it may contain polytetrafluoroethylene, etc. Among these, ultra-high molecular weight polyethylene is preferred as the material for porous membranes. Ultra-high molecular weight polyethylene refers to thermoplastic polyethylene with extremely long chains, and its molecular weight is over one million, typically preferably between 2 and 6 million.

[0161] It is preferable to use two or more filters with different pore structures in the filtration process, and it is more preferable to have 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 process according to the embodiment of the present invention is preferably a multi-stage filtration process in which the material to be purified is passed through two or more filters, each having at least one different characteristic selected from the group consisting of filter material, pore size, and pore structure.

[0163] (Multi-stage filtration process) The multi-stage 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 a multi-stage filtration process. The purification apparatus 10 has a production tank 11, a filtration device 16, and a filling device 13, and each of these units is connected by a pipeline 14. The filtration device 16 has filter units 12(a) and 12(b) connected by a pipeline 14. A control valve 15(a) is located in the pipeline between the filter units 12(a) and 12(b). Note that while Figure 1 illustrates the case with two filter units, three or more filter units may be used.

[0164] In Figure 1, the material to be purified is stored in the manufacturing tank 11. Next, a pump (not shown) located in the pipeline 14 is activated, and the material to be purified is sent from the manufacturing tank 11 through the pipeline 14 to the filtration device 16. The direction of transfer of the material to be purified within the purification device 10 is indicated by F1 in Figure 1.

[0165] The filtration device 16 consists of filter units 12(a) and 12(b) connected by a pipeline 14. Each of the two filter units houses a cartridge filter having at least one different filter selected from the group consisting of pore size, material, and pore structure. The filtration device 16 has the function of filtering the material to be purified supplied through the pipeline. There are no particular limitations 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] When the pump is activated, the material to be purified is supplied to the filter unit 12(a) and filtered. The material filtered in the filter unit 12(a) is depressurized as needed by the control valve 15(a), supplied to the filter unit 12(b), and filtered.

[0167] Furthermore, the purification apparatus does not necessarily have to have the control valve 15(a). Also, even if it does have the control valve 15(a), its position does not necessarily have to be on the primary side of the filter unit 12(b), but it may be on the primary side of the filter unit 12(a). Furthermore, devices other than control valves may be used to adjust the supply pressure of the product to be refined. Examples of such components include dampers.

[0168] Furthermore, although each filter in the filtration device 16 forms a cartridge filter, the filters that can be used in the purification method according to this embodiment are not limited to the above configuration. For example, the material to be purified may be passed through a filter formed in the shape of a flat plate.

[0169] Furthermore, in the purification apparatus 10 described above, the filtered material to be purified after passing through the filter unit 12(b) is transferred to the filling apparatus 13 and placed in a container. However, the filtration apparatus for carrying out the above purification method is not limited to the above, and may be configured to return the filtered material to be purified after passing through the filter unit 12(b) to the manufacturing tank 11 and pass it through the filter unit 12(a) and filter unit 12(b) again. The above filtration method is called recirculation filtration. In the purification of the material to be purified by recirculation filtration, at least one of two or more filters is used two or more times. In this specification, the operation of returning the filtered material to be purified after filtering by each filter unit to the manufacturing tank is counted as one recirculation. The number of cycles should be appropriately selected depending on the components of the product being purified.

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

[0171] The above 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, trifluoroethylene chloride-ethylene copolymer resin, vinylidene fluoride resin, trifluoroethylene chloride copolymer resin, and vinyl fluoride resin.

[0172] The above-mentioned metal material is not particularly limited, and known materials can be used. Examples of metallic materials include those in which the combined content of chromium and nickel exceeds 25% by mass of the total mass of the metallic material, with 30% by mass or more being preferred. There is no particular upper limit on the combined content of chromium and nickel in the metallic material, but 90% by mass or less is preferred. Examples of metallic materials include stainless steel and nickel-chromium alloys.

[0173] There are no particular limitations on the stainless steel, and known stainless steels can be used. Among these, alloys containing 8% by mass or more nickel are preferred, and austenitic stainless steels containing 8% by mass or more nickel are more preferred. Examples of austenitic stainless steels include SUS (Steel Use Stainless) 304 (8% by mass Ni content, 18% by mass Cr content), SUS304L (9% by mass Ni content, 18% by mass Cr content), SUS316 (10% by mass Ni content, 16% by mass Cr content), and SUS316L (12% by mass Ni content, 16% by mass Cr content).

[0174] The nickel-chromium alloy is not particularly limited, and any known nickel-chromium alloy can be used. Among these, a nickel-chromium alloy with a nickel content of 40-75% by mass and a chromium content of 1-30% by mass is preferred. Examples of nickel-chromium alloys include Hastelloy (trade name, same hereinafter), Monel (trade name, same hereinafter), and Inconel (trade name, same hereinafter). More specifically, examples include Hastelloy C-276 (Ni content 63% by mass, Cr content 16% by mass), Hastelloy-C (Ni content 60% by mass, Cr content 17% by mass), and Hastelloy C-22 (Ni content 61% by mass, Cr content 22% by mass). Furthermore, the nickel-chromium alloy may, if necessary, contain boron, silicon, tungsten, molybdenum, copper, and cobalt in addition to the alloys mentioned above.

[0175] The method for electropolishing the metal material is not particularly limited, and known methods can be used. For example, the methods described in paragraphs 0011 to 0014 of Japanese Patent Publication No. 2015-227501 and paragraphs 0036 to 0042 of Japanese Patent Publication No. 2008-264929 can be used.

[0176] It is presumed that, due to electropolishing, the chromium content in the passive layer of the metal material surface becomes higher than the chromium content in the matrix phase. Therefore, it is presumed that using a refining apparatus in which the wetted parts are made from electropolished metal material will make it less likely for metal-containing particles to leak into the refined material. 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 finishing the buffing is not particularly limited, but #400 or smaller is preferred as it tends to reduce surface irregularities of the metal material. It is preferable that buffing be 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. Examples of steps other than the filtration step include a distillation step, a reaction step, and an electrostatic removal step.

[0178] (Distillation process) The distillation process involves distilling the material to be purified, which contains an organic solvent, to obtain the distilled material. The method of distilling the material to be purified is not particularly limited, and known methods can be used. Typically, a distillation column is placed on the primary side of the purification apparatus already described, and the distilled material to be purified is introduced into a production tank. In this case, there are no particular restrictions on the wetted parts of the distillation column, but it is preferable that they be formed from the corrosion-resistant materials described above.

[0179] (Reaction process) The reaction step is a process of reacting raw materials to produce a product to be purified, which contains an organic solvent as a reactant. There are no particular limitations on the method of producing the product to be purified, and known methods can be used. Typically, a method is to place the reaction vessel on the primary side of the production tank (or distillation column) of the purification apparatus described above, and introduce the reactant into the production tank (or distillation column). In this case, there are no particular restrictions on the wetted parts of the reaction vessel, but it is preferable that they be formed from the corrosion-resistant materials described above.

[0180] (static elimination process) The static elimination process is a process that reduces the charge potential of the material to be purified by removing static electricity from it. The method of static elimination is not particularly limited, and known static elimination methods can be used. One example of a static elimination method is to bring the object to be purified into contact with a conductive material. The contact time for bringing the material to be refined into contact with the conductive material is preferably 0.001 to 60 seconds, more preferably 0.001 to 1 second, and even more preferably 0.01 to 0.1 seconds. Examples of conductive materials include stainless steel, gold, platinum, diamond, and glassy carbon. One method for bringing the material to be purified into contact with a conductive material is to place a grounded mesh made of a conductive material inside a conduit and pass the material to be purified through it.

[0181] The purification of the product to be purified, including all associated steps such as opening containers, cleaning containers and equipment, filling solutions, and analysis, is preferably carried out in a cleanroom. The cleanroom should preferably be a cleanroom with a cleanliness level of Class 4 or higher as defined by the international standard ISO 14644-1:2015 established by the International Organization for Standardization. Specifically, it is preferable that the cleanroom 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] While there are no particular restrictions on the storage temperature of the chemical solution, a storage temperature of 4°C or higher is preferable because it makes it less likely for trace amounts of impurities contained in the chemical solution to leach out, resulting in superior effects of the present invention.

[0183] [Chemical solution container] The chemical solution produced by the purification method described above may be stored in a container until use. Such a container, along with the chemical solution (or resist composition) contained within it, is collectively called a chemical solution container. The chemical solution is taken out of the stored chemical solution container and used.

[0184] As the container for storing the above chemical solution, for semiconductor device manufacturing applications, a container with a high cleanliness inside and little elution of impurities is preferable. Specific examples of usable containers include the "Clean Bottle" series manufactured by Asahi Kasei Chemicals Corporation and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd., but are not limited thereto.

[0185] As the container, for the purpose of preventing contamination of impurities into the chemical solution, it is also preferable to use a multilayer bottle having a six-layer structure of the inner wall of the container with six types of resins or a multilayer bottle having a seven-layer structure of six types of resins. Examples of such containers include the containers described in Japanese Patent Application Laid-Open No. 2015-123351.

[0186] The liquid contact part of this container is preferably made of the corrosion-resistant material or glass already described. In terms of obtaining a more excellent effect of the present invention, it is preferable that 90% or more of the area of the liquid contact part is made of the above material, and it is more preferable that the entire liquid contact part is made of the above material.

Examples

[0187] The present invention will be described in more detail based on the following examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0188] Furthermore, in preparing the chemical solutions for the examples and comparative examples, the handling of containers, preparation, filling, storage, and analytical measurements were all carried out in a cleanroom meeting ISO Class 2 or 1 standards. To improve measurement accuracy, when measuring organic impurities and metal atoms below the detection limit in normal measurements, the chemical solution was concentrated to 1 / 100th of its original volume for measurement, and the content was calculated by converting it back to the concentration of the solution before concentration. The equipment used for purification, as well as filters and containers, were thoroughly washed with a chemical solution purified using the same method on the surfaces that came into contact with the chemical solution before use.

[0189] [Purification of chemical solution 1] A commercially available product containing cyclohexanone (CHN) as an organic solvent was prepared, and the chemical solution was produced by filtration using a purification apparatus similar to that shown in Figure 1, except that it had a filtration system with four filter units arranged in series along a pipeline and no control valve, and a pipeline that allowed the filtered product to be returned to the production tank after filtration by the downstreammost filter unit. Each filter unit had the following filters arranged from the primary side. (These are listed 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 of polymer of PTFE and PES (polyethylene sulfonic acid), indicated as "IEX" in the table). • Nylon filter (pore size: 10 nm, fiber membrane; indicated as "Nylon" in the table.) • UPE filter (pore size: 3nm, porous membrane; indicated as "UPE" in the table.) The purified material passed through the four filter units described above was returned to the manufacturing tank, and this process was repeated eight times to obtain the chemical solution.

[0190] [Purification of chemical solutions 2-30] Chemical solutions 2 to 30 were obtained by purifying the product containing the organic solvent listed in Table 1 under the conditions listed in Table 1. Each chemical solution was obtained by passing the product to be purified through the filters listed in Table 1, from the first filter to the fourth filter in order (a blank filter column indicates that the filter was not used for that chemical solution; for example, chemical solution 2 was passed through the first to fourth filters), and repeating this process the number of times indicated in "Number of Circulations". Please note that the purified materials listed in Table 1 were procured from different lots. Therefore, the components other than the organic solvents initially contained in each purified 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: Methylisobutylcarbinol IPA: Isopropanol • PC / PGMEA (1:9): A 1:9 (v / v) mixture of PC and PGMEA. • EL: Ethyl lactate • IEX / 10nm: IEX filter with a pore size of 10nm • PTFE: Polytetrafluoroethylene filter (a porous membrane) • UPE: Ultra-high molecular weight polyethylene filter (a porous membrane). • Nylon: A filter made of nylon (a fibrous membrane).

[0192] [Table 1]

[0193] [Evaluation of the number of particles with a particle size of 0.5 to 17 nm contained in the drug solution] The content (number of particles) of particles with a particle size 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. The surface of the substrate with the chemical solution layer was scanned with laser light, and scattered light was detected. 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 location of the defects to determine the composition of the defects. Using this method, the number of metal nanoparticles, Pb nanoparticles, and Ti nanoparticles on the substrate was determined, and this was used to determine the number of particles per unit volume of the chemical solution (particles / cm³). 3 The particle size distribution of metal nanoparticles was also determined using the same method as described above. Similarly, the composition of the metal nanoparticles (elemental metal and oxides of metal atoms) and their association state with high-boiling point organic compounds were also identified. For the analysis, a combination of KLA-Tencor's SP-5 wafer inspection system and Applied Materials' SEMVision G6 fully automated defect review and classification system was used. The presence or absence of high-boiling point organic compounds was measured using gas chromatography-mass spectrometry.

[0194] Furthermore, for samples where particles of the desired particle size could not be detected due to limitations in the resolution of the measuring device, detection was performed using the method described in paragraphs 0015 to 0067 of Japanese Patent Publication No. 2009-188333. Specifically, SiO was deposited onto a substrate by CVD (chemical vapor deposition). X A layer was formed, and then a chemical solution layer was formed to cover the above layer. Next, the above 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, the scattered light was detected, the volume of the protrusions was calculated from the scattered light, and the particle size was calculated from the volume of the protrusions. Table 2 shows the measurement results for each chemical solution, as well as the particle count ratios calculated based on these results.

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

[0196] [Table 2]

[0197] [Table 3]

[0198] Note that Table 2 is described separately as Table 2 (Part 1) and Table 2 (Part 2). The measurement results of each chemical solution are described in the corresponding rows of the above two tables. For example, for Chemical Solution 1, cyclohexanone is used as the organic solvent, the number of contained particles of metal nanoparticles is 1.0×10 4 per cm 3 , and as the particle size distribution (number %) based on the number of metal-containing particles, metal-containing particles with a particle size of less than ired as 20%, metal nanoparticles with a particle size of 0.5 nm or more and less than 3 nm are 50%, metal nanoparticles with a particle size of 3 nm or more and less than 5 nm are 20%, and metal nanoparticles with a particle size of 5 nm or more and ired as 10% are included. Particle A is 2% based on the number with respect to the total of metal nanoparticles, and the total of Particle B and Particle C is included as 98%, and A / (B + C) is 2.0×10 -2 , it contains a high-boiling organic compound, and based on the number, Particle U is 94% and Particle V is 6% with respect to the total of metal nanoparticles, and U / V is 1.6×10 1 . Among the metal nanoparticles, the number of Pb nanoparticles is 1.3×10 2 per cm 3 , the number of Ti nanoparticles is 5.4×10 2 per cm 3 , and Pb / Ti is 2.4×10 -1 . For other chemical solutions, they are described in the table in the same manner as Chemical Solution 1.

[0199] [Example 1] The defect suppression performance was evaluated using chemical solution 1, prepared as described above, as a pre-wetting solution. The resist compositions used are as follows:

[0200] [Resist composition 1] Resist composition 1 was obtained by mixing each component in the following composition. ·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) 600 g of cyclohexanone was placed in a 2 L flask and nitrogen was purged at a flow rate of 100 mL / min for one hour. Then, 4.60 g (0.02 mol) of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the temperature was raised to 80°C. Next, the monomers listed below and 4.60 g (0.02 mol) of polymerization initiator V-601 (manufactured by 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 the addition was complete, the reaction was continued at 80°C for another 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 and 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) on a standard polystyrene basis, determined by gel permeation chromatography (GPC) (solvent: THF (tetrahydrofuran)), was 11200, and the molecular weight dispersion (Mw / Mn) was 1.45. The composition and other details are shown in Table 3 below.

[0205] [Table 4]

[0206] <Photoacid Generator (B)> The following were used as photoacid generators.

[0207] [ka]

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

[0209] [ka]

[0210] (Performance in suppressing residue defects, bridge defects, and stain-like defects) The residue defect suppression performance, bridge defect suppression performance, and stain defect suppression performance of the chemical solution were evaluated using the following methods. The test was conducted using SOKUDO's coater developer "RF" 3S They used "". First, AL412 (manufactured by Brewer Science) was coated onto a silicon wafer and baked at 200°C for 60 seconds to form a 20 nm thick resist underlayer film. A pre-wetting solution (chemical solution 1) was then applied on top of that, and resist composition 1 was coated on top of that. A bake (PB: Prebake) was performed at 100°C for 60 seconds to form a 30 nm thick resist film.

[0211] This resist film was exposed using an EUV lithography machine (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. The film was then heated at 85°C for 60 seconds (PEB: Post Exposure Bake). Next, it was developed with an organic solvent-based developer for 30 seconds and rinsed for 20 seconds. Finally, the wafer was 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] Images of the above patterns were acquired, and the obtained images were analyzed using the above analytical apparatus to measure the number of residues in the unexposed areas per unit area (labeled "Residue Defect Suppression Performance" in Table 4) and the number of bridge-like defects between patterns (Bridge Defects, labeled "Bridge Defect Suppression Performance" in Table 4). In addition, defects in which no metal atoms were detected were defined as stain-like defects and measured as a result of EDX (Energy Dispersive X-ray Analysis) at the coordinates where defects were detected (labeled "Stain-like 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: The number of defects was less than 30. A: The number of defects was between 30 and 60. B: The number of defects was between 60 and 90. C: The number of defects was between 90 and 120. D: The number of defects was between 120 and 150. E: The number of defects was between 150 and 180. F: The number of defects was 180 or more.

[0214] (Uniformity of pattern width) Images of the above pattern were acquired, and the obtained images were analyzed using the above-described analytical device to determine the LWR (Line Width Roughness). Specifically, when observing from the top of the pattern, the distance from the center of the pattern to the edge was observed at arbitrary points, and the measurement variability was evaluated using 3σ. The results were evaluated according to the following criteria to assess the uniformity performance of the pattern width. The results are shown in Table 4.

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

[0216] [Examples 2-21 and 23-28] Except for using chemical solutions 2-21 and 23-28 instead of chemical solution 1, the residue defect suppression performance, bridge defect suppression performance, stain defect suppression performance, and pattern width uniformity performance of each chemical solution were evaluated in the same manner as described above. The results are shown in Table 4.

[0217] [Comparative Examples 1 and 2] Except for using chemical solutions 29 and 30 instead of chemical solution 1, the performance of suppressing residue defects, suppressing bridge defects, suppressing stain-like defects, and uniformity of pattern width were evaluated in the same manner as described above. The results are shown in Table 4.

[0218] [Example 22] Except for not using a pre-wetting solution and using chemical solution 22 as the developer, the residue defect suppression performance, bridge defect suppression performance, stain defect suppression performance, and pattern width uniformity performance of chemical solution 22 were evaluated in the same manner as described above. The results are shown in Table 4.

[0219] [Table 5]

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

[0221] Next, the number of particles with a particle size of 0.5 to 17 nm contained in the chemical solution of resist composition 2 was evaluated using the same method as described above, and it was found to be about the same as in Example 1. Furthermore, when patterns were formed using the same method as in Example 1, except that resist composition 2 was used and a pre-wetting solution was not used, the residual defect suppression performance, bridge defect suppression performance, pattern width uniformity performance, and stain-like defect suppression performance were investigated, and the results were the same as in Example 1.

[0222] The results in Table 4 show that the chemical solutions described in Examples 1-21 and 23-28, when used as pre-wetting solutions, exhibited excellent residue defect suppression performance, excellent bridge defect suppression performance, excellent pattern width uniformity performance, and excellent stain-like defect suppression performance. Furthermore, the results in Table 4 show that the chemical solution described in Example 22, when used as a developer, exhibited 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, exhibited excellent residue defect suppression performance, excellent bridge defect suppression performance, excellent pattern width uniformity performance, and excellent stain-like defect suppression performance.

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

[0225] Chemical solution 1, in which A / (B+C) was less than 1.0, exhibited superior residue defect suppression performance, superior bridge defect suppression performance, superior pattern width uniformity performance, and superior stain-like defect suppression performance compared to chemical solution 10.

[0226] A / (B+C) = 1.0 × 10 -1 Chemical solution 1, described below, exhibited superior residue defect suppression performance, superior bridge defect suppression performance, superior pattern width uniformity performance, and superior stain-like defect suppression performance compared to chemical solution 12.

[0227] U / V is 1.0 x 10 1 Compared to chemical solution 16, chemical solution 1 exhibited superior performance in suppressing residue defects, superior performance in suppressing bridge defects, superior uniformity of pattern width, and superior performance in suppressing stain-like defects.

[0228] Pb / Ti is 1.0 × 10 -3Chemical solution 1, with a value of ~2.0, exhibited superior residue defect suppression performance, superior bridge defect suppression performance, superior pattern width uniformity performance, and superior stain-like defect suppression performance compared to chemical solutions 17 and 20. [Explanation of symbols]

[0229] 10 Purification equipment 11 Manufacturing Tanks 12(a), 12(b) Filter Unit 13 Filling equipment 14 Conduit 15(a) Regulating valve 16 Filtration device

Claims

1. Organic solvents and Metal-containing particles containing metal atoms measurable by an energy-dispersive X-ray analyzer, A chemical solution containing, a resist composition containing, Of the aforementioned metal-containing particles, the number of metal nanoparticles with a particle size of 0.5 to 17 nm per unit volume of the drug solution is 6.0 × 10 ３ ~8.5 x 10 ６ pieces / cm ３ And, The metal nanoparticles consist of at least one selected from the group consisting of particles A, which are composed of the elemental metal atom; particles B, which are composed of the oxide of the elemental metal atom; and particles C, which are composed of the elemental metal atom and the oxide of the elemental metal atom. The ratio of the number of particles A to the sum of the number of particles B and C per unit volume of the aforementioned chemical solution is 1.0 × 10 －１ The following is: Resist composition. The particle size is determined by either Method 1 or Method 2 below. 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 laser light, scattered light is detected to determine the particle size, and elemental analysis is performed by energy-dispersive X-ray spectroscopy to identify the target particles. Method 2: A SiOx layer is formed on a substrate by CVD, then a chemical solution layer is formed using the chemical solution so as to cover the SiOx layer, and then the composite layer having the SiOx layer and the chemical solution layer is dry-etched. Light is irradiated onto the resulting protrusions, scattered light is detected, the volume of the protrusions is calculated from the scattered light, the particle size of the particles is determined from the volume of the protrusions, and elemental analysis is performed by energy-dispersive X-ray analysis to identify the target particles.

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

3. The resist composition according to claim 2, wherein the particle size distribution has a maximum value in the range of particle size of 0.5 nm or more and less than 5 nm.

4. A resist composition according to any one of claims 1 to 3, used in the manufacture of semiconductor devices.

5. Furthermore, the resist composition according to any one of claims 1 to 4 contains an organic compound having a boiling point of 300°C or higher.

6. The resist composition according to claim 5, wherein at least a portion of the metal nanoparticles is particle U containing the organic compound.

7. At least a portion of the metal nanoparticles, Particles U containing the aforementioned organic compound, and Particles V that do not contain the aforementioned organic compound, The ratio of the number of particles U to the number of particles V per unit volume of the aforementioned chemical solution is 1.0 × 10 １ The resist composition according to claim 5 or 6.

8. The resist composition 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. The resist composition according to any one of claims 1 to 8, wherein the metal nanoparticles include metal nanoparticles containing Pb atoms and metal nanoparticles containing Ti atoms.

10. The ratio of the number of Pb-containing metal nanoparticles to the number of Ti-containing metal nanoparticles per unit volume of the aforementioned chemical solution is 1.0 × 10⁻⁶. －３ A resist composition according to any one of claims 1 to 9, wherein the value is ~2.0.

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