Method for manufacturing a resist composition

Abstract

The present invention provides a method for manufacturing a resist composition in which impurities are further reduced and the occurrence of defects in the resist film can be suppressed. [Solution] A method for manufacturing a resist composition, comprising: manufacturing a resist composition using a manufacturing apparatus equipped with a filter including a filter; removing the filter from the manufacturing apparatus; cleaning the manufacturing apparatus from which the filter has been removed using a cleaning solution; analyzing the cleaning solution used in the cleaning step; and attaching another filter to the manufacturing apparatus from which the filter has been removed, and manufacturing a resist composition, wherein, before the manufacturing step, the cleaning step and the analysis step are each performed at least once until the concentration of the resist composition components contained in the cleaning solution in the analysis step is less than 300 ppb.

Description

Technical Field

[0001] The present invention relates to a method for producing a resist composition. Background Art

[0002] In lithography technology, for example, a method is used in which a resist film made of a resist material is formed on a substrate, the resist film is subjected to selective exposure, and then development processing is performed, thereby forming a resist pattern of a predetermined shape on the resist film.

[0003] In the manufacture of semiconductor devices and liquid crystal display devices, pattern miniaturization and multilayering of substrates have been progressing rapidly due to advances in lithography technology. With the progress of miniaturization of resist patterns, along with improvement of various lithographic properties, resist materials are also required to suppress the occurrence of defects in resist films. Along with this, there is an increasing demand for removing foreign substances (impurities) mixed into resist compositions. In particular, impurities contained in a resist composition may cause the occurrence of defects. Therefore, control of the concentration of impurities contained in a resist composition is considered important.

[0004] For example, Patent Document 1 discloses a method for producing a purified resist composition in which metal impurities contained in the resist composition are reduced and problems such as pattern collapse are less likely to occur, and in order to obtain a purified resist composition produced by said production method, etc., a method for producing a purified resist composition is described, which includes step (i) of filtering the resist composition through a filter having a porous structure in which adjacent spherical cells communicate with each other. Prior Art Documents Patent Documents

[0005] Patent Document 1 Japanese Patent No. 7195418 Summary of the Invention Problems to be Solved by the Invention

[0006] In recent years, with the further miniaturization of patterns and the multilayering of substrates, the demand for reducing impurities in resist compositions has become even stricter in semiconductor manufacturing processes. Therefore, there is a greater need than ever for technologies that can suppress defect occurrence in resist films. The present invention has been made in view of the above circumstances, and aims to provide a method for producing a resist composition in which impurities are further reduced and the occurrence of defects in the resist film can be suppressed. [Means for solving the problem]

[0007] Through their investigations, the inventors have found that conventional cleaning methods result in insufficient cleaning of the resist composition manufacturing equipment. As a result, organic components originating from previous resist composition manufacturing lots remain in the equipment and contaminate the next resist composition, making it difficult to manufacture a resist composition that can suppress the occurrence of defects. Furthermore, the possibility of organic components originating from previous manufacturing lots contaminating the next resist composition can lead to problems such as a significant decrease in the efficiency of factor analysis when problems occur. This invention was made in view of the above circumstances, and the present invention was completed by finding that a method for producing a resist composition can be obtained in which impurities in the resist composition are further reduced and the occurrence of defects in the resist film is suppressed.

[0008] In other words, one aspect of the present invention includes a disassembly step of disassembling and removing some components of the manufacturing apparatus after manufacturing a resist composition using the manufacturing apparatus, A cleaning step in which the other components of the manufacturing apparatus from which some of the aforementioned components have been removed are cleaned using a cleaning solution, An analysis step in which the cleaning solution used in the cleaning step is taken out and analyzed, A manufacturing process for manufacturing a resist composition, comprising attaching the aforementioned components to the manufacturing apparatus from which the aforementioned components have been removed, A method for producing a resist composition having the following characteristics: Prior to the manufacturing process, the washing process and the analysis process are each performed at least once until the concentration of the resist composition components contained in the washing solution in the analysis process is less than 300 ppb. This is a method for manufacturing a resist composition. [Effects of the Invention]

[0009] According to the method for producing a resist composition of the present invention, impurities in the resist composition can be reduced, and the occurrence of defects in the resist film can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of a manufacturing apparatus used in the present invention. [Figure 2] Figure 2 is a schematic diagram illustrating the cleaning process according to an embodiment of the present invention. [Figure 3] Figure 3 is a schematic diagram illustrating a cleaning process according to another embodiment of the present invention. [Modes for carrying out the invention]

[0011] In this specification and in the claims, "mass%" and "weight%" are synonymous, "parts by mass" and "parts by weight" are synonymous, and "mass ratio" and "weight ratio" are synonymous.

[0012] [Method for manufacturing a resist composition] A method for manufacturing a resist composition according to an embodiment of the present invention includes a disassembly step of disassembling and removing some components of the manufacturing apparatus after manufacturing the resist composition using the manufacturing apparatus, A cleaning step in which the other components of the manufacturing apparatus from which some of the aforementioned components have been removed are cleaned using a cleaning solution, An analysis step in which the cleaning solution used in the cleaning step is taken out and analyzed, A manufacturing process for manufacturing a resist composition, comprising attaching the aforementioned components to the manufacturing apparatus from which the aforementioned components have been removed, A method for producing a resist composition comprising: Prior to said production step, said washing step and said analysis step are each performed at least once until the component concentration of said resist composition contained in said washing liquid in said analysis step is less than 300 ppb.

[0013] Through the washing step, other members of the production apparatus from which some members have been removed can be washed. Residues of the resist composition produced before the washing step (hereinafter sometimes referred to as a first resist composition) are removed from the production apparatus, thereby preventing the residues from being mixed into the resist composition produced subsequently (hereinafter sometimes referred to as a second resist composition), and a high-purity resist composition can be obtained. It is preferable that some members of the production apparatus disassembled and removed in the disassembling step are separately washed using a cleaning liquid. By washing the production apparatus after removing some members, organic components derived from previous production lots can be prevented from being mixed into the subsequently produced resist composition, and a high-purity resist composition can be obtained. Furthermore, by performing the washing step and the analysis step each at least once until the component concentration of the first resist composition contained in the washing liquid in the analysis step is less than 300 ppb, a high-purity resist composition can be obtained. In addition, since it can be confirmed that polymer components, which were conventionally difficult to remove from production apparatuses, have been sufficiently removed, mixing of residues of the first resist composition produced before the washing step can be efficiently prevented.

[0014] <Disassembling Step> The method for producing a resist composition according to an embodiment of the present invention comprises, after producing a resist composition using a production apparatus, a disassembling step of disassembling and removing some members of said production apparatus. Some members refer to members that can be disassembled and removed (disassemblable) among the members constituting the production apparatus, and may be all or part of the disassemblable members.

[0015] In the disassembling step, after producing a first resist composition using a production apparatus, some members of the production apparatus are disassembled and removed. Said some members are members that can be disassembled and removed from among the members constituting the production apparatus as described above, and examples thereof include piping, filters, pumps, and the like. For example, in the case of the production apparatus illustrated in FIG. 1, the supply pipe 110, the pump 151, the filter 140, and the circulation pipe 109 can be disassembled and removed. Members that can be disassembled and removed may be washed with a cleaning liquid in the washing step described later.

[0016] (Resist Composition) The resist composition according to the embodiment of the present invention is not particularly limited as long as it can form a resist film, and examples thereof include resist compositions containing a polymer and an organic solvent. Further, as one embodiment of the resist composition, there can be mentioned a resist composition containing, as polymers, a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of a known acid, an acid generator component (B) (hereinafter also referred to as "component (B)") that generates an acid upon exposure, and an organic solvent component (S) (hereinafter also referred to as "component (S)"). The resist composition may further contain, as an optional component, at least one compound (E) (hereinafter also referred to as "component (E)") selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and derivatives thereof. In addition, the resist composition may further contain, as optional components, an acid diffusion control component (D) (hereinafter referred to as "component (D)") and a fluorine-based additive component as a hydrophobic resin (hereinafter referred to as "component (F)").

[0017] The component (A) is not particularly limited, and those conventionally proposed as base components for resist compositions can be used.

[0018] Examples of component (A) include polyester resins, polyamide resins, polyurethane resins, epoxy resins, phenolic resins, acrylic resins, polyvinyl acetate resins, cellulose resins, styrene resins, hydroxystyrene resins, or copolymers thereof. (A) For example, the base components described in Japanese Patent Publication No. 2025-178097, International Publication No. 2024 / 053689, Japanese Patent Publication No. 2023-010711, and Japanese Patent Publication No. 2004-43777 can be used as components. (A) More specifically, it is preferable that the component (A) contains a constituent unit (a1) which has an acid-degradable group whose polarity increases with the action of an acid, and a constituent unit (a10) which contains a hydroxystyrene skeleton. Furthermore, it may also contain a constituent unit (a2) which contains any of a lactone-containing cyclic group, a -SO2--containing cyclic group, or a carbonate-containing cyclic group, a constituent unit (a3) ​​which contains a polar group-containing aliphatic hydrocarbon group, and a constituent unit (a4) which contains an acid-nondissociable aliphatic cyclic group.

[0019] (B) The component is not particularly limited, and any acid generators previously proposed for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts; oximesulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators, among many others. (B) For example, the acid generators described in Japanese Patent Publication No. 2025-063109, Japanese Patent Publication No. 2023-010711, and International Publication No. 2023 / 162552 can be used as component (B).

[0020] Furthermore, the (S) component can be any solvent that can dissolve each component used to form a homogeneous solution, and any solvent can be appropriately selected from those conventionally known as solvents for chemically amplified resist compositions.

[0021] Component (S) can be any substance capable of dissolving the polymer, such as lactones, ketones, polyhydric alcohols; compounds having ester bonds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or compounds having ether bonds such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME)]; cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents, dimethyl sulfoxide, etc.

[0022] Component (D) acts as an acid diffusion control component that traps the acid generated by exposure in the resist composition. Component (D) is not particularly limited, and any acid diffusion control agent previously proposed for chemically amplified resist compositions can be used. (D) For example, an acid diffusion control agent described in Japanese Patent Publication No. 2025-178097 can be used as component (D).

[0023] Component (F) is used to impart water repellency to the resist film and, by being used as a separate resin from component (A), improves lithography properties. As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used.

[0024] When a resist film is formed using the resist composition and selective exposure is performed on the resist film, acid is generated in the exposed areas of the resist film. The solubility of component (A) in the developer changes due to the action of this acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0025] In this disclosure, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition. Furthermore, the resist composition according to the embodiment of the present invention may be used for an alkaline development process in which an alkaline developer is used for the development process during resist pattern formation, or for a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development process. In other words, the resist composition according to the embodiment of the present invention may be a "positive-type resist composition for alkaline development processes" that forms a positive-type resist pattern in an alkaline development process, or a "negative-type resist composition for solvent development processes" that forms a negative-type resist pattern in a solvent development process.

[0026] The above-mentioned positive-type resist composition and negative-type resist composition are not particularly limited, and known compositions can be used, such as KrF resist, ArF resist, EUV resist, EB resist, etc. For example, resist compositions described in Japanese Patent Publication No. 2021-21773, Japanese Patent Publication No. 2019-159323, Japanese Patent Publication No. 2021-92759, Japanese Patent Publication No. 2021-92659, Japanese Patent Publication No. 2017-37108, Japanese Patent Publication No. 2017-37300, Japanese Patent Publication No. 2020-90628, etc. can be used.

[0027] (Preparation of the first resist composition) In this process, the first resist composition is manufactured using a manufacturing apparatus. There are no particular restrictions on the method for manufacturing the first resist composition, but the components constituting the first resist composition are introduced into the manufacturing apparatus, and other components are mixed in as needed. The mixing of the components constituting the first resist composition can be carried out under known conditions. It is preferable to use an unused filter for the filtration filter of the manufacturing apparatus used to manufacture the first resist composition. Details of the manufacturing apparatus will be described later.

[0028] (manufacturing equipment) The manufacturing apparatus used in the embodiments of the present invention is not particularly limited as long as it is capable of producing a resist composition. The manufacturing apparatus may include, for example, a preparation tank, piping, a pump, a filter (including a filter), a supply port, and a valve. Examples of detachable components in the manufacturing apparatus used in embodiments of the present invention include piping, filters, pumps, and the like. Figure 1 is a schematic diagram showing one embodiment of a manufacturing apparatus used in an embodiment of the present invention. The manufacturing apparatus 100 includes a filter 140 and a tank 101, the tank 101 having a supply port 161 for supplying resist composition material. The tank 101 and the filter 140, which includes a filter, are connected by a supply pipe 110, allowing fluid (resist composition, cleaning solution, etc.) to be transferred between the tank 101 and the filter 140. A pump 151 is located in the supply pipe 110.

[0029] In Figure 1, the manufacturing apparatus 100 includes a tank 101 and a filter 140, but the manufacturing apparatus that can be used in the method for manufacturing a resist composition according to the embodiment of the present invention is not limited to this.

[0030] In the manufacturing apparatus 100, the resist composition material supplied to the manufacturing apparatus 100 from the supply port 161 flows into the filter 140 via the tank 101, valve 132, and pump 151. The fluid discharged from the filter 140 is collected in the tank 101 via valve 131. The manufacturing apparatus 100 may also include a valve 133 for discharging the manufactured resist composition to the outside. The resist composition produced by the manufacturing apparatus 100 can be stored in the container 102 as the final product. The resist composition filtered by the filter 140 can be stored in the container 102 via a circulation pipe 109 connecting the filter 140 and the tank 101, by switching valves 131 and 133 provided in the circulation pipe 109.

[0031] <Washing Process> The cleaning step in the embodiment of the present invention includes cleaning the other components of the manufacturing apparatus (hereinafter sometimes simply referred to as the manufacturing apparatus), from which some components have been removed, using a cleaning solution.

[0032] Other components of the manufacturing apparatus refer to components of the manufacturing apparatus that are not disassembled, and these non-disassemblable components may include both disassemblable and non-disassemblable components. It is preferable to disassemble detachable components and remove them as separate parts, but even if a component is detachable, components that are directly connected to non-detachable components, or components surrounding non-detachable components, may be cleaned without being disassembled as other components.

[0033] In the process of cleaning other components using a cleaning solution (hereinafter sometimes referred to as the non-disassembly cleaning process), it is preferable that all of the internal wetted parts of the other components of the manufacturing apparatus are cleaned using the cleaning solution. The other components cleaned in the non-disassembly cleaning process are those that were not removed in the disassembly process. These other components may include components that can be disassembled and removed, but since it is preferable to disassemble and clean components that can be disassembled and removed, it is preferable to clean components that cannot be disassembled and removed or that are difficult to disassemble and remove as other components in the non-disassembly cleaning process. Examples of other components include a fixed preparation tank and surrounding piping, a product filling valve, fixed piping, an in-line measuring device, and the like.

[0034] There are no particular restrictions on the cleaning method in the non-disassembly cleaning process, and known methods can be used. An example of cleaning in the cleaning process will be explained using Figures 1 and 2. For example, in the case of the manufacturing apparatus illustrated in Figure 1, the supply pipe 110, pump 151, filter 140, and circulation pipe 109 are disassembled and removed in the disassembly process, and the other components of the manufacturing apparatus, such as the tank 101, valve 132, valve 131, and valve 133, are cleaned in the cleaning process. Other components of the manufacturing apparatus may be cleaned individually, or they may be cleaned in groups of non-disassemblable parts. Figure 2 is a schematic diagram illustrating the cleaning process according to an embodiment of the present invention. For example, as shown in Figure 2, in the disassembly process described above, the supply pipe 110, pump 151, filter 140, and circulation pipe 109 can be disassembled and removed, and the valves 131 and 133, which are other components of the manufacturing apparatus, can be cleaned separately as non-disassemblable parts (1) 171, and the tank 101 and valve 132 as non-disassemblable parts (2) 172.

[0035] The non-disassemblable parts (1) 171 may be cleaned by, for example, attaching cleaning pipes 201 to valves 131 and 133 and cleaning them with a cleaning solution. For example, a tank 202 filled with cleaning solution may be connected to the pipe 201, and the cleaning solution may be transferred to clean the inside of valves 131 and 133. The tank 202 filled with cleaning solution may be pressurized to any pressure for the transfer of the cleaning solution. For pressurization, an inert gas such as nitrogen gas may be used.

[0036] After cleaning the non-disassemblable parts (1) 171, the cleaning solution can be discharged to waste liquid tanks 211 and 212 using cleaning pipes 201, etc., in the direction of liquid flow indicated by the arrows. In addition, disassemblable components can be disassembled and discharged. In this case, the number of cleaning cycles is defined as the point at which the entire amount of cleaning solution supplied to the non-disassemblable part (1) 171 has been discharged. The term "total amount" refers to 90% or more by volume of the supplied cleaning solution, with 95% or more by volume being more preferable.

[0037] Figure 3 is a schematic diagram illustrating a cleaning process according to another embodiment. For example, as shown in Figure 3, a cleaning pipe 201 and a pump (not shown) may be attached to valves 131 and 133, and cleaning may be performed using a cleaning solution. Furthermore, a tank 202 filled with cleaning solution may be connected, and the cleaning solution may be transferred by a pump (not shown) to clean the inside of valves 131 and 133. The cleaning solution may be circulated within the non-disassemblable part (1) 171 and the cleaning pipe 201 for cleaning (hereinafter also referred to as "circulation cleaning").

[0038] After cleaning the non-disassemblable parts (1) 171, the cleaning solution can be discharged by disassembling the detachable components or by discharging it from the outlet of the tank 202 or from each valve (valve 131, valve 133). In this case as well, the number of cleaning cycles is defined as the point at which the entire amount of cleaning solution supplied into the non-disassemblable part (1) 171 has been discharged.

[0039] For example, the non-disassemblable parts (2) 172 may be cleaned by attaching cleaning pipes 205 to the valve 132 and tank 101 and cleaning them with a cleaning solution. A pump 251 may be attached to the cleaning pipes 205 to allow the cleaning solution to flow through.

[0040] The non-disassemblable part (2) 172 may be cleaned by supplying cleaning fluid into the non-disassemblable part (2) 172 from the supply port 161 of the tank 101. There are no particular restrictions on the amount of cleaning fluid supplied, but it is preferable to supply an amount sufficient to thoroughly clean the wetted parts of the tank 101 in the non-disassemblable part (2) 172. The amount of cleaning solution used for one cleaning cycle is preferably 1 volume% or more, more preferably 3 volume% or more, and even more preferably 5 volume% or more, relative to the capacity of tank 101, in addition to the amount that completely fills the piping. Furthermore, the amount of cleaning solution used is preferably 30 volume% or less, more preferably 20 volume% or less, and even more preferably 15 volume% or less, relative to the capacity of tank 101, in addition to the amount that completely fills the piping. The cleaning solution according to the embodiment of the present invention will be described later.

[0041] By cleaning while transferring the cleaning solution, the components of the resist composition adhering to the supply piping 110 around the tank 101, and to the wetted parts of the tank 101, valve 132, etc., can be efficiently dispersed and / or more efficiently dissolved by the cleaning solution, thereby cleaning the manufacturing equipment.

[0042] There are no particular limitations on the method of cleaning the inside of the tank 101 using the cleaning solution, but one example is to clean it by rotating the stirring blades (not shown) provided in the tank 101. There are no particular limitations on the time for cleaning the tank with the cleaning solution, and it can be appropriately selected depending on the material of the wetted parts of the tank 101, the type of resist composition to be manufactured, etc. Generally, a cleaning time of 0.1 seconds to 48 hours is preferred for cleaning the tank.

[0043] The cleaning solution may be circulated within the non-disassemblable parts (2) 172 and the cleaning pipes 205 for cleaning. An example of circulating cleaning of the non-disassemblable part (2) 172 will be explained using Figure 2. First, the cleaning fluid supplied into the non-disassemblable part (2) 172 from the supply port 161 of the tank 101 flows in the direction of the fluid flow indicated by the arrow in Figure 2, passes through the cleaning pipe 205, and flows into the tank 101. At this time, a pump 251 and a valve (not shown) may be provided, and the pump 251 may be operated. The cleaning fluid supplied to the tank 101 returns to the tank 101 again (circulates) via the valve 132 and the cleaning pipe 205. After cleaning the non-disassemblable parts (2) 172, the cleaning solution can be discharged by disassembling the detachable components or by discharging it from the tank's outlet or valve. While transferring the cleaning fluid supplied into the non-disassemblable part (2) 172, the valve 132 may be opened and the pump 251 operated to circulate the cleaning fluid multiple times within the non-disassemblable part (2) 172 through the cleaning piping 205 and the tank 101, after which the cleaning fluid may be discharged from an outlet (not shown) provided in the tank 101. In this case as well, the number of cleaning cycles is defined as the point at which the entire amount of cleaning solution supplied to the non-disassemblable part (2) 172 has been discharged.

[0044] The number of washes, wash time, and amount of wash solution used can be arbitrarily set according to the resin composition, solvent composition, viscosity, etc., contained in the first resist composition manufactured before the wash process.

[0045] The number of washes should be such that, in the analysis step described later, it is detected that the component concentration of the resist composition in the washing solution is less than 300 ppb. In other words, in the embodiment of the present invention, washing is repeated until it is detected that the component concentration of the resist composition in the washing solution is less than 300 ppb. Regarding the specific number of washes, for example, two or more washes are preferable, and three or more washes are more preferable. There is no particular upper limit on the number of washes, but from the viewpoint of reducing manufacturing time and manufacturing costs, 20 washes or less is preferable, 10 washes or less is more preferable, and 5 washes or less is even preferable. Washing two or more times makes it easier to obtain a resist composition with better defect suppression performance.

[0046] (Disassembly and cleaning) The cleaning process may also include a step of cleaning components that can be further disassembled and removed with a cleaning solution. In the disassembly process described above, some of the components removed during the disassembly process may be cleaned with a cleaning solution during the cleaning process (hereinafter sometimes referred to as disassembly cleaning). For disassembly and cleaning, it is preferable to perform spray cleaning, rinsing, or swishing cleaning of the disassembled manufacturing equipment components using a wash bottle filled with cleaning solution. Alternatively, it is preferable to perform immersion cleaning by soaking the components in a container, cleaning tank, etc. By disassembling and cleaning components that can be removed, the connection points of the components can be thoroughly cleaned, thereby improving the cleanliness of the manufacturing equipment.

[0047] The disassembly and cleaning time and the amount of cleaning solution used can be arbitrarily set according to the resin composition, solvent composition, viscosity, etc., contained in the first manufactured resist composition before the cleaning process. In disassembly and cleaning, shower washing of components is preferably carried out until no organic components can be visually confirmed to be attached. There are no particular time constraints, but for example, the shower washing time is preferably 10 seconds or more, more preferably 20 seconds or more, and even more preferably 30 seconds or more. Furthermore, from the viewpoint of manufacturing time and manufacturing cost, the shower washing time is preferably 10 minutes or less, more preferably 8 minutes or less, and even more preferably 5 minutes or less.

[0048] (Cleaning solution) The cleaning solution used in the cleaning step in the embodiments of the present invention is not particularly limited, and known cleaning solutions can be used. Examples of cleaning solutions include alcohols; ether-based organic solvents such as alkylene glycol monoalkyl ether carboxylates and alkylene glycol monoalkyl ethers; ketone-based organic solvents such as cyclic lactones (preferably having 4 to 10 carbon atoms) and monoketone compounds that may have a ring (preferably having 4 to 10 carbon atoms); and ester-based organic solvents such as alkyl lactate, alkyl alkoxypropionate, alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.

[0049] The cleaning solution may include alcohols such as propanol (IPA), butanol (nBA), iAA (isoamyl acetate), and MIBC (methyl isobutylcarbinol); glycol-based organic solvents such as PGME (propylene glycol monomethyl ether) and PGMEA (propylene glycol monomethyl ether acetate); hydrocarbon-based organic solvents such as CyHe (cyclohexane); and DBCPN (cyclopentanone). It is preferable to contain at least one selected from the group consisting of ether-based organic solvents such as dimethylacetal, EL (ethyl lactate), and HBM (methyl 2-hydroxyisobutyrate); ester-based organic solvents such as GBL (γ-butyrolactone); and ketone-based organic solvents such as DMSO (dimethyl sulfoxide), EC (ethylene carbonate), PC (propylene carbonate), NMP (1-methyl-2-pyrrolidone), MAK (2-heptanone), cyclopentanone, cyclohexanone, acetone, and MEK (methyl ethyl ketone). It is more preferable to contain at least one selected from the group consisting of PGMEA, NMP, PGME, nBA, GBL, MIBC, EL, DMSO, MAK (2-heptanone), cyclohexanone, acetone, and MEK. The cleaning solution may be used individually or in combination of two or more types.

[0050] In addition to the above, other examples of cleaning solutions include alcohols such as methanol, ethanol, methoxyethanol, butoxyethanol, methoxypropanol, and ethoxypropanol; glycol-based organic solvents such as dipropylene glycol monomethyl ether, dipropylene glycol, and ethylene glycol monobutyl ether; ketone-based organic solvents such as MIBK (methyl isobutyl ketone) and DIBK (diisobutyl ketone); ether-based organic solvents such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ester-based organic solvents such as ethyl acetate and ethyl cellosolve acetate; aromatic compounds such as benzene, toluene, and xylene; and chlorinated hydrocarbons such as dichloromethane, dichloroethane, dichloroethylene, and trichloroethylene.

[0051] Furthermore, a solution containing water added to the above-mentioned organic solvent may be used as the cleaning solution. Adding water can facilitate the cleaning of water-soluble organic impurities that are difficult to remove with cleaning using only the organic solvent.

[0052] The cleaning solution preferably contains at least one selected from the group consisting of glycol-based organic solvents, ester-based organic solvents, lactone-based organic solvents, and ketone-based organic solvents, more preferably a glycol-based organic solvent, and may also contain propylene glycol monomethyl ether acetate.

[0053] The cleaning time and the amount of cleaning solution used can be arbitrarily set according to the resin composition, solvent composition, viscosity, etc., contained in the first resist composition manufactured before the cleaning process.

[0054] <Analysis process> The analysis step in the embodiment of the present invention is the step of taking out the cleaning solution used in the cleaning step and analyzing it. There are no particular restrictions on the method of extracting the cleaning solution, but for example, after the cleaning process is completed, the drained cleaning solution can be taken into a sample container and extracted. The cleaning solution may be partially or entirely extracted. If only a portion is extracted, the remaining cleaning solution in the manufacturing equipment can be reused in further cleaning processes.

[0055] In the analysis step of the embodiment of the present invention, the cleaning solution is collected from the cleaning solution used in the cleaning step. The collected cleaning solution is analyzed without concentration. The analysis may include a step to increase the concentration of the resist composition components contained in the cleaning solution before analysis (concentration step), but it is preferable to analyze without concentration in order to shorten the analysis time and prevent contamination by other components. By performing the analysis without concentration, contamination by other components can be prevented. If there is a possibility of impurities being mixed into the resist composition being manufactured, problems may arise such as a significant decrease in the efficiency of factor analysis when problems occur.

[0056] The method for analyzing the component concentrations of the resist composition contained in the cleaning solution is not particularly limited and includes, for example, liquid chromatography, gas chromatography, Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-Vis). In this embodiment, it is preferable to perform the analysis of the component concentrations of the resist composition in the analysis step using a liquid chromatography method, as this allows for highly sensitive detection. In other words, it is preferable to analyze the washing solution using liquid chromatography in the analysis process. The component concentrations of the resist composition contained in the washing solution can be analyzed using known methods such as liquid chromatography, gas chromatography, Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-Vis).

[0057] In the method for producing a resist composition according to an embodiment of the present invention, prior to the manufacturing process described later, the washing step and the analysis step are each performed at least once until the concentration of the resist composition components contained in the washing solution in the analysis step is less than 300 ppb. If the concentration of the components of the first resist composition contained in the cleaning solution during the analysis step is greater than 300 ppb, the cleaning step is performed again. After performing the further cleaning step at least once, the cleaning step and analysis step are repeated until the concentration of the components of the first resist composition contained in the cleaning solution removed from the manufacturing apparatus is 300 ppb or less. Once the concentration of the components of the first resist composition contained in the cleaning solution is less than 300 ppb, the manufacturing step for producing the second resist composition can be initiated. The concentration of the components of the first resist composition contained in the cleaning solution is preferably 250 ppb or less, more preferably 200 ppb or less, even more preferably 150 ppb or less, even more preferably 130 ppb or less, and particularly preferably 120 ppb or less, and most preferably substantially absent (below the detection limit of the measuring device). According to the method for producing a resist composition that includes the above steps, a resist composition having excellent defect suppression performance can be obtained.

[0058] (Components of the resist composition contained in the cleaning solution) The components of the first resist composition contained in the cleaning solution that are analyzed in the analysis step are components different from the organic solvent contained in the cleaning solution, and are intended to be the components that make up the first resist composition manufactured before cleaning, and the reaction products of each component, with a particular emphasis on organic components. Specifically, the components of the resist composition that are analyzed in the analysis step include the above-mentioned base material component (A) (hereinafter also referred to as "component (A)"), acid generator component (B) (hereinafter also referred to as "component (B)"), organic solvent component (S) (hereinafter also referred to as "component (S)"), compound (E) (hereinafter also referred to as "component (E)"), acid diffusion control component (D) (hereinafter referred to as "component (D)"), fluorine-based additive component (hereinafter referred to as "component (F)"), etc.

[0059] When manufacturing a new second resist composition, if organic components different from those specified in the design are mixed in, it is anticipated that unintended aggregation or reaction of components may occur in the second resist composition, leading to the occurrence of defects.

[0060] <Manufacturing process for the second resist composition> The manufacturing process in the embodiment of the present invention is a process of manufacturing a resist composition by attaching some components to a manufacturing apparatus from which some components have been removed.

[0061] In this process, a second resist composition is manufactured using a cleaned manufacturing apparatus. There are no particular restrictions on the method for preparing the second resist composition, but the components constituting the second resist composition are introduced into the manufacturing apparatus, and other components are mixed in as needed. The mixing of the components constituting the second resist composition can be carried out under known conditions. The second resist composition produced in this process may be the same as the first resist composition produced before the cleaning process, and the second resist composition produced in this process and the first resist composition produced before the cleaning process may have the same or different compositions.

[0062] Some of the components attached in this process may be those that were removed in the disassembly process described above and then cleaned separately, or unused components may be used. Of the components, it is preferable to use an unused filter. Since it is difficult to remove organic impurities from used filters even after repeated cleaning processes, using an unused filter prevents the contamination of the second resist composition with impurities, thereby obtaining a high-purity resist composition.

[0063] <Other processes> The method for producing the resist composition described above may include other steps, within the scope of achieving the effects of the present invention. These other steps are not particularly limited, but examples include a step in the cleaning step to remove residual cleaning solution from the inside or surface of the component using compressed gas, an ultrasonic cleaning step for the disassemblable component, and a calibration step and a data analysis step in the analysis step.

[0064] According to the method for manufacturing a resist composition according to the embodiment of the present invention described above, it is possible to manufacture a resist composition with further reduced organic impurities. For example, by forming a resist film using this resist composition, defect occurrence can be suppressed, and the electrical properties of semiconductor devices and the like can be improved and stabilized.

[0065] [Defect suppression performance] A resist composition produced by the method for producing a resist composition according to an embodiment of the present invention can form a resist film that suppresses defect occurrence. The defect suppression performance (defect suppression performance) of the resist composition according to the embodiment of the present invention can be evaluated by measuring the number of defects in the resist film on a substrate (support) formed with the resist composition. The defect suppression performance (defect suppression performance) of the resist composition according to the embodiment of the present invention can also be evaluated by measuring the number of defects on a pattern formed by exposing the resist film to a predetermined light source and developing it with a predetermined developer. Pattern defects can be evaluated using known methods.

[0066] The defect suppression performance of a resist composition obtained by a method for manufacturing a resist composition according to an embodiment of the present invention is determined more specifically by forming a resist film on a support using the resist composition of the above embodiment and measuring the number of defects in the resist film on the support. For example, when a silicon wafer with a diameter of 300 mm is used as the support, the number of defects per silicon wafer is preferably less than 150, and more preferably less than 100. The resist film can be formed by known methods.

[0067] The various materials used in the resist compositions of the embodiments described above (for example, resist solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) are preferably free from impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0068] As for the method of measuring the number of defects, methods commonly used for measuring the number of defects on a substrate can be used. Specifically, examples include measuring the number of defects using defect inspection equipment such as the KLA-Tencor dark-field defect inspection system "SP-5 (product name)".

[0069] While fewer defects are preferable for optimal performance, it is practically difficult to eliminate extremely small defects entirely. However, it is preferable that the number of defects larger than 50 nm be less than 150, more preferably less than 100, and even more preferably less than 70. The above criteria can be appropriately selected depending on the application of the resist composition, i.e., the pattern shape, line width, layout, etc.

[0070] As described above, the method for producing a resist composition according to the embodiment of the present invention reduces impurities in the resist composition and makes it possible to produce a resist composition that is excellent in suppressing the occurrence of defects in the resist film. [Examples]

[0071] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0072] <Synthesis of polymer compound A-1>

[0073] A polymer compound was synthesized by radical polymerization using monomers that derive the constituent units of polymer compound (A)-1 shown below, in a predetermined molar ratio. For the obtained polymer compound, the carbon-13 nuclear magnetic resonance spectrum ( 13 The copolymerization composition ratio (molar ratio of each constituent unit in the polymer compound) of the polymer compound, determined by 13C-NMR, and the weight-average molecular weight (Mw) and molecular weight dispersion (Mw / Mn) in terms of standard polystyrene, determined by GPC measurement, are also shown.

[0074] [ka]

[0075] [Examples 1-4] <Preparation of Resist Composition 1> Using a resist composition manufacturing apparatus equipped with a filter including a filtration filter as shown in Figure 1, a preparation tank, piping, a pump, and a valve, the components shown in Table 1 were mixed and dissolved in the preparation tank, sensitivity and viscosity were adjusted by a predetermined method, and then the resist composition 1 was prepared (manufactured) by circulating it through the apparatus and filtering it with the filter.

[0076] [Table 1]

[0077] In Table 1, each abbreviation has the following meaning. The numbers in brackets [] in Table 1 indicate the amount of each component, and the unit of the amount is parts by mass.

[0078] (A)-1: A base component consisting of a polymer compound represented by the above chemical formula (A)-1. (B)-1: An acid generating agent component consisting of the compound represented by the following chemical formula (B)-1. (D)-1: An acid diffusion control agent component consisting of the compound represented by the following chemical formula (D)-1. (E)-1: Salicylic acid (S)-1: A mixed solvent in a mass ratio of propylene glycol monomethyl ether acetate (PGMEA) / propylene glycol monomethyl ether (PGME) = 20 / 80.

[0079] [ka]

[0080] <Cleaning of resist composition manufacturing equipment and analysis of cleaning solution> After removing some components from the manufacturing equipment, such as the supply piping, pump, filter, and circulation piping, shower cleaning (disassembly cleaning) was performed using a wash bottle filled with cleaning solution. In addition, cleaning pipes were connected to the non-disassemblable parts (1) (valve and surrounding circulation piping) and (2) (tank, valve and surrounding supply piping) in Figure 2, respectively, and the inside was cleaned by passing or circulating cleaning solution through them (circulation cleaning). The specific procedure is as follows.

[0081] (a) Cleaning of disassembled parts (a-1) Some components of the resist composition manufacturing apparatus were disassembled and removed, including a portion of the supply piping, a pump, a filter, and circulation piping. (a-2) The supply piping, pump, filter, and circulation piping that could be individually disassembled were further disassembled. The filter was removed from the filter and discarded as it would not be reused. (a-3) The inside and connecting parts of the disassembled components were individually shower-cleaned using a wash bottle or similar container filled with cleaning solution. (b) Cleaning of non-disassemblable parts (1) (valves and surrounding piping) (b-1) The washing solution was prepared by filling a pressurized container with it. (b-2) A pressurized container filled with cleaning solution and cleaning piping were connected to the non-disassemblable part (1). (b-3) By pressurizing the pressurized container, the cleaning solution was passed through the non-disassemblable part (1). The inside was cleaned by opening and closing the valves, and the cleaning solution was discharged from each valve. The discharged cleaning solution was discarded. (b-4) After the predetermined amount of cleaning solution was discharged, the cleaning solution was taken out from the filling valve and analyzed. (c) Cleaning of non-disassemblable parts (2) (fixed preparation tank and surrounding piping) (c-1) A predetermined amount of cleaning solution was poured into a fixed preparation tank. (c-2) Cleaning piping and a pump were connected to the non-disassemblable part (1). (c-3) The cleaning solution was circulated and the area was cleaned. (c-4) After circulating the cleaning solution, it was extracted and analyzed.

[0082] For cleaning the decomposition parts, acetone was used, and for cleaning the non-decomposition parts, propylene glycol monomethyl ether acetate (PGMEA) was used. For cleaning the decomposition parts, a shower wash was performed using a wash bottle filled with acetone until no organic components could be visually confirmed to be attached. For cleaning the non-decomposition parts (1), PGMEA was used in excess of 500 volume% relative to the capacity of the filling valve and surrounding piping. For cleaning the non-decomposition parts (2), PGMEA was added in an amount of 5 volume% relative to the capacity of the fixed preparation tank, and the inside was circulated for 10 minutes to clean. Of the above cleaning process, the procedure [(b-1) to (b-3)] was repeated for non-disassemblable parts (1), and the procedure [(c-1) to (c-3)] was repeated for the number of times (number of cleaning cycles) indicated in Table 2 for non-disassemblable parts (2). After each cleaning cycle was completed, the used cleaning solution was collected in a glass bottle, and the content of organic components in the cleaning solution was measured and calculated using the analytical method described below.

[0083] (Analysis process) The amount of organic components contained in the washing solution after washing was measured using a liquid chromatography system manufactured by Thermo Fisher Scientific. A combination of ultrapure water and an organic solvent was used as the mobile phase. The results are shown in Table 2.

[0084] <Preparation of Resist Composition 2> After the cleanliness of the manufacturing apparatus was confirmed through the above process, a new filter was installed, and using the cleaned resist composition manufacturing apparatus, the components shown in Table 1 were mixed and dissolved to prepare (manufacture) resist composition 2, which had the same composition as resist composition 1. The preparation (manufacturing) was carried out using the same procedure as for resist composition 1.

[0085] <Resist film formation> Using Tokyo Electron's "CLEAN TRACK LITHIUS Pro Z (product name)," the resist composition prepared in <Preparation of Resist Composition 2> was rotary coated onto a 300 mm diameter silicon wafer (hereinafter referred to as "wafer") at 1500 rpm, and then the wafer was dried to form a resist film.

[0086] <Evaluation of defect suppression performance of resist compositions> The defect suppression performance of the resist film formed by the above-described <formation of resist film> was evaluated using the following method. The number of defects in the resist film on this wafer was measured using KLA-Tencor's "SP-5 (product name)" and evaluated according to the following evaluation criteria. The measurement was limited to defects with a size of 50 nm or larger. The results are shown in Table 2. A: Less than 30 defects B: Number of defects is 30 or more, but less than 70. C: Number of defects is 70 or more, but less than 100. D: Number of defects is 100 or more

[0087] [Comparative Examples 1 and 2] The same procedure as in Example 1 was followed, except that the resist composition was manufactured by circulating cleaning the inside of the manufacturing equipment with a cleaning solution the number of times shown in Table 2 (stationary cleaning) without disassembly and cleaning.

[0088] [Table 2]

[0089] These results showed a correlation between the concentration of organic components in the cleaning solution and the number of defects in the resist film formed by the resist composition, confirming that the cleanliness of the manufacturing equipment affects the quality of the resist composition. It was found that by controlling the concentration of organic components in the cleaning solution to less than 300 ppb, it is possible to suppress the number of defects in the resist film formed by the resist composition to less than 100. [Explanation of symbols]

[0090] 100 Manufacturing equipment 101, 202 tanks 102 Container 109 Circulation piping 110 Supply piping 131, 132, 133 valves 140 Filtration Machine 151, 251 pumps 161 Supply port 171 Non-degradable site (1) 172 Non-degradable site (2) 201, 205 Cleaning pipes 211, 212 Waste liquid tanks

Claims

1. A disassembly step of disassembling and removing some components, including the filter, from the manufacturing apparatus after manufacturing a resist composition using a manufacturing apparatus equipped with a filter, A cleaning step in which the other components of the manufacturing apparatus from which some of the aforementioned components have been removed are cleaned using a cleaning solution, An analysis step in which the cleaning solution used in the cleaning step is taken out and analyzed, A manufacturing process for manufacturing a resist composition, comprising attaching the aforementioned components to the manufacturing apparatus from which the aforementioned components have been removed, A method for producing a resist composition having the following characteristics: In the manufacturing process described above, the filter included in the filter attached to the manufacturing apparatus is an unused filter. Prior to the manufacturing process, the washing process and the analysis process are each performed at least once until the concentration of the resist composition components contained in the washing solution in the analysis process is less than 300 ppb. A method for producing a resist composition.

2. In the analysis step described above, the washing solution is analyzed using liquid chromatography. A method for producing the resist composition according to claim 1.

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