Method for cleaning resist coating equipment, method for inspecting quality of resist composition, and method for producing resist composition

Abstract

To provide a cleaning method of resist coating equipment, which can suppress occurrence of defects in a resist film formed using resist coating equipment, the defects being derived from the resist coating equipment, and to provide a quality inspection method of a resist composition and a production method of a resist composition.SOLUTION: Provided is a cleaning method of resist coating equipment, comprising: step 1 of cleaning the resist coating equipment using solution A having an SP value of 16.0-21.5 MPa1 / 2; and step 2 of cleaning, after the step 1, the resist coating equipment using solution B having an SP value of more than 21.5 MPa1 / 2 and 30.0 MPa1 / 2 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for cleaning a resist coating apparatus, a method for inspecting the quality of a resist composition, and a method for producing a resist composition. [Background technology]

[0002] 2. Description of the Related Art In manufacturing processes for semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrated circuits), fine processing is carried out by lithography using a resist composition. Lithography methods include a method in which a coating film (resist film) of a resist composition is formed on the surface of a semiconductor substrate using a resist coating apparatus, and the resulting film is then exposed to light and then developed.

[0003] Resist compositions used in lithography often include compositions that contain a resin (acrylic resin) that has a structural unit derived from a (meth)acrylic acid ester in its main chain. For example, Patent Document 1 discloses a positive resist composition that contains a resin component (A) that has a specific functional group in an ester side chain portion and has a structural unit derived from a (meth)acrylic acid ester in its main chain, and whose alkali solubility increases under the action of acid, an acid generator component (B) that generates acid upon exposure, and an organic solvent (C). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-241385 A Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, as a quality control of a resist composition, a defect inspection method has been performed in which the resist composition is formed into a resist film and the quality of the resist composition is evaluated based on the number of defects in the resist film formed. The present inventors have investigated the above-mentioned quality control method of a resist composition, and have found that in addition to defects originating from the resist composition, defects presumably originating from the resist coating device used to form the resist film occur, making it impossible to strictly control the quality of the resist composition, and that there is room for further improvement in the quality control method of a resist composition.

[0006] In view of the above-mentioned circumstances, an object of the present invention is to provide a method for cleaning a resist coating apparatus that can suppress the occurrence of defects originating from the resist coating apparatus in a resist film formed using the resist coating apparatus. Another object of the present invention is to provide a method for inspecting the quality of a resist composition, and a method for producing a resist composition. [Means for solving the problem]

[0007] The present inventors have found that the above problems can be solved by the following configuration.

[0008] [1] A method for cleaning a resist coating device, comprising the steps of: 1 / 2 A step 1 of cleaning the resist coating apparatus using the solvent A, and after the step 1, the SP value is 21.5 MPa. 1 / 2 Over 30.0MPa 1 / 2 and step 2 of cleaning the resist coating apparatus using the following solvent B. [2] The SP value of the above solvent A is 18.5 to 21.5 MPa. 1 / 2 The method for cleaning a resist coating apparatus according to [1], [3] The method for cleaning the resist coating apparatus according to [1] or [2], wherein at least one of the solvent A and the solvent B contains one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents. [4] The method for cleaning a resist coating apparatus according to any one of [1] to [3], wherein the step 1 includes a step 1-1 of cleaning the resist coating apparatus with a solvent A1 contained in the solvent A, and a step 1-2 of cleaning the resist coating apparatus with a solvent A2 contained in the solvent A and having an SP value different from that of the solvent A1, after the step 1-1. [5] The method for cleaning a resist coating apparatus according to [4], wherein the SP value of the solvent A2 is higher than the SP value of the solvent A1. [6] The method for cleaning a resist coating apparatus according to [4] or [5], wherein the solvent A1 includes at least one selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents. [7] The method for cleaning the resist coating apparatus according to any one of [1] to [6], further comprising at least one step selected from the group consisting of a step X of filtering the solvent A used in the step 1 through a filter before the step 1, and a step Y of filtering the solvent B used in the step 2 through a filter before the step 2. [8] The method for cleaning the resist coating apparatus according to any one of [1] to [7], further comprising: a step 4 of coating at least one of the solvents used in the steps 1 and 2 onto the substrate using the resist coating apparatus; and a step 5 of measuring the number of defects on the substrate using a defect inspection apparatus after the step 4, wherein if the number of defects measured in the step 5 exceeds a reference value, at least one step selected from the group consisting of the steps 1 and 2 is carried out again. [9] A method for inspecting the quality of a resist composition, comprising: a resist film forming step of applying a resist composition onto a substrate using a resist coating apparatus that has been cleaned by the cleaning method according to any one of [1] to [8] to form a resist film; and a defect measuring step of measuring the number of defects in the resist film using a defect inspection apparatus.

[10] A method for producing a resist composition, comprising: carrying out a quality inspection of a resist composition in accordance with the quality inspection method according to [9]; and producing a resist composition in which the number of defects in a resist film is reduced, based on the results of the quality inspection.

[11] A method for producing an electronic device, comprising: forming a resist film on a substrate using the resist composition produced by the method according to

[10] ; and producing an electronic device using the resist film. Effect of the Invention

[0009] According to the present invention, there is provided a method for cleaning a resist coating apparatus, which can suppress the occurrence of defects originating from the resist coating apparatus in a resist film formed using the resist coating apparatus. Furthermore, according to the present invention, it is possible to provide a method for inspecting the quality of a resist composition, and a method for producing a resist composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present specification, the notation of groups (atomic groups) that does not indicate whether they are substituted or unsubstituted includes groups that have a substituent as well as groups that have no substituent. For example, an "alkyl group" includes not only an alkyl group that has no substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group). In addition, in the present specification, an "organic group" refers to a group that contains at least one carbon atom. As the substituent, unless otherwise specified, a monovalent substituent is preferred.

[0011] In this specification, "actinic rays" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV light: Extreme Ultraviolet), X-rays, and electron beams (EB). In this specification, "light" means actinic rays or radiation. In this specification, unless otherwise specified, "exposure" includes not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, but also drawing with particle beams such as electron beams and ion beams. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0012] In this specification, the bond direction of the divalent group is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "XYZ", Y may be -CO-O- or -O-CO-. In addition, the above compound may be "X-CO-OZ" or "XO-CO-Z".

[0013] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic. In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (hereinafter also referred to as "molecular weight distribution") (Mw / Mn) are defined as polystyrene-equivalent values ​​measured using a Gel Permeation Chromatography (GPC) apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: refractive index detector).

[0014] In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and specifically, is a value calculated using the following software package 1 based on a database of Hammett's substituent constants and known literature values. Software package 1:Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0015] The pKa can also be calculated by molecular orbital calculations. The specific method is to calculate the pKa of H in aqueous solution based on the thermodynamic cycle. + One method is to calculate the dissociation free energy. + The method of calculating the dissociation free energy can be, for example, calculated by DFT (density functional theory), but various other methods have been reported in the literature, and the method is not limited to these. There are several software programs that can perform DFT, such as Gaussian16.

[0016] In this specification, pKa refers to a value calculated based on a database of Hammett's substituent constants and known literature values ​​using the software package 1, as described above. However, when pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) is adopted. In this specification, pKa refers to "pKa in aqueous solution" as described above, but when the pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" will be used. "Solids" refers to the components that form the resist film, and does not include solvents. In addition, any component that forms the resist film is considered to be a solid even if it is in a liquid state. As used herein, the term "gallon" means "US fluid gallon" with one gallon equaling 3.785412 liters.

[0017] The method for cleaning a resist coating apparatus according to the present invention (hereinafter also referred to as "the present cleaning method") is to clean the resist coating apparatus by subjecting the apparatus to an SP value of 16.0 to 21.5 MPa. 1 / 2After step 1, the resist coating device is cleaned with solvent A having an SP value of 21.5 MPa. 1 / 2 Over 30.0MPa 1 / 2 and washing step 2 using the following solvent B. Although the detailed mechanism by which the cleaning method including the above steps 1 and 2 can suppress the occurrence of defects in the resist film originating from the resist coating apparatus is unclear, the present inventors presume it as follows.

[0018] The present inventors have found that one of the causes of defects occurring in a resist film may be the influence of residues derived from the resist composition adhering to a resist coating device. When a resist composition is applied to a substrate surface to form a resist film, a specific resist coating device is often used repeatedly. Then, while the application of the resist composition is repeated, residues of any of the components contained in the resist composition adhere to the inside of a pipe (hereinafter also referred to as a "resist line") through which the resist composition of the resist coating device passes. Therefore, it is desirable to clean the resist coating device so that the residues of the resist composition do not get mixed into the resist composition that passes through the resist line anew. In this cleaning method, the resist coating apparatus is cleaned using a solvent A that has a predetermined SP value and is relatively compatible with components such as a resin (e.g., a resin whose polarity increases under the action of an acid) that is the main component of the resist composition, and then the resist coating apparatus is cleaned using a solvent B that has a predetermined SP value higher than that of solvent A and is relatively compatible with a highly polar component such as a photoacid generator. Here, the cause of defects caused by the residue of the resist composition is the aggregation of highly polar components such as a photoacid generator. It is presumed that once the highly polar components aggregate, the aggregates become difficult to dissolve in the solvent, which may cause defects in the resist film. Therefore, the inventors presume that by first removing most of the attached residue using solvent A and then cleaning the remaining highly polar components using solvent B that is highly compatible with the highly polar components, it is possible to suppress the incorporation of the residue into a new resist composition and suppress the occurrence of defects in the resist film. Hereinafter, a superior effect of suppressing the occurrence of defects in a resist film will also be referred to as "the effect of the present invention is superior."

[0019] [Resist Coating Device] There are no particular limitations on the resist coating apparatus (hereinafter also simply referred to as "coating apparatus") to be cleaned by the present cleaning method, so long as it is an apparatus having the function of transporting a resist composition and applying the resist composition to the surface of a substrate. An example of a resist coating apparatus is an apparatus that includes a container that contains a resist composition, piping for transporting the resist composition, and a nozzle for discharging the resist composition.

[0020] The container is not particularly limited as long as it has a function of containing the resist composition. Examples of materials constituting the container include resin, glass, metal, and composites thereof. The material of the container can be arbitrarily selected depending on the type of resist composition to be contained. Examples of the container include known containers such as gallon bottles, coated bottles, etc. The gallon bottle may be made of a glass material or a material other than glass.

[0021] The pipe is a member that connects the container and the nozzle. The upstream end of the pipe may, for example, penetrate the top of the container and extend to the vicinity of the bottom of the container. The downstream end of the pipe is connected to the nozzle. The resist composition stored in the container is transferred to the nozzle through this pipe.

[0022] The method of transporting the resist composition inside the piping is not particularly limited, and as will be described later, the resist composition may be transported by introducing a gas into a container to pressurize the resist composition, or by discharging the resist composition using a pump. The piping may be provided with a pump for transporting the resist composition. Examples of the pump include an electric submersible pump, a diaphragm pump, and a centrifugal pump (such as a magnet pump).

[0023] The piping may be provided with a filter for filtering the resist composition in order to remove particles or gel components that may be contained in the resist composition. As the filter and the filter cartridge that houses the filter, known filters and filter cartridges can be used.

[0024] The resist composition transported through the pipe is then discharged onto a substrate through a nozzle. There are no particular limitations on the type of nozzle that the resist composition is equipped with, and any known nozzle capable of discharging the resist composition can be used.

[0025] The resist coating apparatus is not limited to the apparatus having the above configuration, and it is sufficient that the resist coating apparatus has at least a pipe for transporting the resist composition. The liquid-contacting parts (points that come into contact with the liquid) in the resist coating apparatus may be lined or coated with a resistant material such as glass or fluororesin.

[0026] [Method for cleaning resist coating device] This cleaning method is a method for cleaning a resist coating apparatus, and includes the following steps 1 and 2 in this order. Step 1: The coating device is set to a temperature of 16.0 to 21.5 MPa (SP value). 1 / 2 A step of washing with solvent A. Step 2: After step 1, the coating device is heated to a temperature of 21.5 MPa. 1 / 2 Over 30.0MPa 1 / 2 A process of washing with the following solvent B.

[0027] <Process 1> Step 1 is a step of cleaning the coating apparatus with the above-mentioned solvent A. As described above, it is presumed that by carrying out this step, most of the residues derived from the resist composition (e.g., residues derived from the resin) adhering to the coating apparatus can be removed.

[0028] Solvent A used in this process has an SP value of 16.0 to 21.5 MPa. 1 / 2There are no particular limitations on the solvent as long as it is within the range. Among them, the effect of the present invention is more excellent when the SP value is 18.5 to 21.5 MPa. 1 / 2 Preferred is a solvent in which The SP value of the present invention is calculated using the Fedors method described in "Properties of Polymers, Vol. 2, 1976 Publication." The calculation formula and parameters of each substituent used are shown in Table 1 below. SP value (Fedors method) = [(sum of cohesive energies of each substituent) / (sum of volumes of each substituent)] 0.5

[0029] [Table 1]

[0030] Solvent A is not particularly limited as long as it satisfies the above conditions, and examples thereof include amide-based solvents, alcohol-based solvents, ester-based solvents, glycol ether-based solvents (including glycol ether-based solvents having a substituent), ketone-based solvents, alicyclic ether-based solvents, aliphatic hydrocarbon-based solvents, aromatic ether-based solvents, and aromatic hydrocarbon-based solvents. In particular, solvent A preferably contains one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, glycol ether-based solvents, and ketone-based organic solvents, and more preferably contains one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents.

[0031] Tables 2 and 3 show specific examples of solvent A. In Table 2, the SP value is 16.0 MPa. 1 / 2 More than 18.5MPa 1 / 2 Table 3 lists solvent A with an SP value of 18.5 to 21.5 MPa. 1 / 2 Describe the solvent A.

[0032] [Table 2]

[0033] [Table 3]

[0034] [Table 4]

[0035] [Table 5]

[0036] [Table 6]

[0037] Examples of solvent A include, in addition to the solvents listed in Tables 2 and 3 above, 2,2,4-trimethylpentane, 2-methylpentane, and the like.

[0038] As the solvent A, only one type may be used, or a mixed solvent of two or more types of solvents may be used. The SP value of the mixed solvent is defined as the mass average value obtained by averaging the SP values ​​of each solvent based on the mixing ratio (mass ratio) of each solvent. The mass average SP value is 16.0 to 21.5 MPa 1 / 2 The mixed solvent can be used as solvent A.

[0039] In step 1, the coating apparatus is cleaned using a solvent A. In cleaning the coating apparatus, at least the portion of the coating apparatus that comes into contact with the resist composition when the resist composition is supplied (hereinafter also referred to as the "liquid-contacting portion") is cleaned with the solvent. More specifically, containers containing the respective solvents are installed in place of the container containing the resist composition in the above-mentioned resist coating apparatus, and the respective solvents are sent out in accordance with the above-mentioned transfer method and discharged from the nozzle, thereby cleaning the resist line of the coating apparatus.

[0040] The number of times the coating device is washed in step 1 is not particularly limited, and may be one or more times. In steps 1 to 3, when the coating device is washed continuously or intermittently using a solvent of the same type and composition, the number of washings is counted as "one time." That is, in step 1, washing may be performed only once using one type of solvent A, or washing may be performed two or more times using two or more solvents each different in type or composition.

[0041] In terms of achieving better effects of the present invention, it is preferable that step 1 at least includes step 1-1 of cleaning the resist coating apparatus with solvent A1 contained in solvent A, and, after step 1-1, step 1-2 of cleaning the resist coating apparatus with solvent A2 which is contained in solvent A and different from solvent A1.

[0042] Solvent A1 and solvent A2 have an SP value of 16.0 to 21.5 MPa. 1 / 2 Any solvents may be used as long as they are within the above range and are different from each other. In particular, in terms of achieving even better effects of the present invention, it is preferred that the SP value of solvent A2 is higher than the SP value of solvent A1.

[0043] Specific examples of solvent A1 and solvent A2 are the same as the specific examples of solvent A described above. In particular, solvent A1 and solvent A2 preferably contain one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, glycol ether-based solvents, and ketone-based organic solvents, and more preferably contain one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents.

[0044] During cleaning, a filter may be placed in the pipe through which the solvent A passes. By placing a filter, residues peeled off from the inside of the pipe by cleaning can be reliably removed without adhering to the inside of the pipe. Examples of the filter that can be used include the filter used in step X described below.

[0045] The liquid temperature of solvent A during washing is not particularly limited and may be, for example, 20° C. or higher. The upper limit of the liquid temperature of solvent A is appropriately selected based on the flash point of solvent A and safety considerations such as the heat resistance of the equipment. The amount of solvent used in one cleaning in step 1 is not particularly limited, and can be appropriately selected depending on the size of the coating device, the material of the liquid-contacting part, and the composition of the resist composition, and is, for example, 2 gallons or more, and preferably 4 gallons or more. The upper limit is not particularly limited, and the more the amount of solvent used, the better, but in terms of time and cost, it is, for example, 10 gallons or less. In step 1, the delivery of the solvent may be stopped and a period of time may be provided during which the liquid-contacting parts in the coating device are immersed in the solvent.

[0046] Solvent A is preferably filtered before use. That is, the present cleaning method preferably includes, before step 1, step X of filtering solvent A through a filter. When step 1 includes step 1-1 using the above-mentioned solvent A1 and step 1-2 using the above-mentioned solvent A2, it is preferable to carry out, as step X, a step of filtering the solvent A1 through a filter before step 1-1, and a step of filtering the solvent A2 through a filter before step 1-2.

[0047] The type of filter used in step X is not particularly limited, and any known filter may be used. The pore size of the filter is preferably 0.20 μm or less, more preferably 0.10 μm or less, even more preferably 0.05 μm or less, and most preferably 0.01 μm or less.

[0048] Examples of the material of the filter used in step X include fluororesins such as polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, polyvinylidene fluoride, and ethylenetetrafluoroethylene copolymer, polyolefin resins such as polypropylene and polyethylene, polyamide resins such as nylon 6 and nylon 66, and polyimide resins (examples of the polyimide filter include the polyimide filters described in JP 2017-064711 A and JP 2017-064712 A), and it is preferable that the filter contains a fluororesin. The filter may be washed in advance with an organic solvent. Also preferred is a filter with reduced elution such as that disclosed in JP2016-201426A.

[0049] When filtering with a filter, multiple filters may be connected in series or parallel. When multiple filters are used, filters with different pore sizes and / or materials may be used in combination. When filtering with a filter, circulating filtration may be performed. As a method of circulating filtration, for example, a method disclosed in JP-A-2002-062667 is preferable. After the above-mentioned filtration, impurities may be further removed from the solvent A using an adsorbent.

[0050] <Process 2> Step 2 is a step of cleaning the coating apparatus using solvent B after step 1. It is presumed that by carrying out this step, residues derived from highly polar components such as a photoacid generator, among the residues derived from the resist composition adhering to the coating apparatus, can be more effectively removed.

[0051] Solvent B used in this process has an SP value of 21.5 MPa. 1 / 2 Over 30.0MPa 1 / 2 There are no particular limitations as long as the solvent falls within the following range. In particular, the solvent should have an SP value of 21.5 MPa. 1 / 2 Over 25.0MPa 1 / 2 Preferred are solvents which are:

[0052] Solvent B is not particularly limited as long as it satisfies the above conditions, and examples thereof include amide-based solvents, alcohol-based solvents, ester-based solvents, glycol ether-based solvents (including glycol ether-based solvents having a substituent), ketone-based solvents, alicyclic ether-based solvents, aliphatic hydrocarbon-based solvents, aromatic ether-based solvents, and aromatic hydrocarbon-based solvents. In particular, solvent B preferably contains one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, glycol ether-based solvents, and ketone-based organic solvents, and more preferably contains one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents.

[0053] Specific examples of the solvent B are shown in Table 4.

[0054] [Table 7]

[0055] As the solvent B, only one type may be used, or a mixed solvent of two or more types of solvents may be used.

[0056] The combination of solvent A and solvent B is not particularly limited, but in terms of better effects of the present invention, it is preferable that at least one of solvent A and solvent B contains one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents, and it is more preferable that both solvent A and solvent B contain one or more selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents.

[0057] In step 2, the coating device is cleaned using solvent B. The method, number of times, and conditions (liquid temperature, amount used, etc.) for cleaning the coating device in step 2, including preferred embodiments thereof, may be the same as those in step 1 above.

[0058] Solvent B is preferably filtered through a filter before use. That is, the present cleaning method preferably includes, before step 2, step Y of filtering solvent B through a filter. The filter may be the one described in step X. The filter used in the step Y preferably contains a fluororesin. The procedure for step Y may be the same as that described for step X.

[0059] <Other processes> This cleaning method may include steps other than step 1 and step 2, and may further include, for example, step 3 of cleaning the coating apparatus with solvent C having an SP value different from both solvent A and solvent B. That is, solvent C has an SP value of 16.0 MPa. 1 / 2 Solvents with an SP value of less than 30.0 MPa 1 / 2 The solvent is either

[0060] There are no particular limitations on the solvent C as long as it has the above-mentioned SP value. Table 5 shows specific examples of solvent C.

[0061] [Table 8]

[0062] As the solvent C, only one type may be used, or a mixed solvent of two or more types of solvents may be used.

[0063] In step 3, the coating device is cleaned using solvent C. The method, number of times, and conditions (liquid temperature, amount used, etc.) for cleaning the coating device in step 3, including preferred embodiments thereof, may be the same as those in step 1 above. The solvent C is preferably filtered through a filter before use. In other words, when the present cleaning method includes step 3, the present cleaning method preferably includes, before step 3, step Z of filtering the solvent C used in step 3 through a filter. The filters used include those described in step X. The filter used in step Z preferably contains a fluororesin. The procedure for step Z may be the same as that described for step X.

[0064] The present cleaning method preferably further comprises at least one step selected from the group consisting of the above-mentioned step X and the above-mentioned step Y, and more preferably comprises both the step X and the step Y. When the method includes step 3, it is preferable to carry out at least one step selected from the group consisting of step X, step Y, and step Z, and it is more preferable to carry out all of step X, step Y, and step Z.

[0065] In each cleaning step (step 1, step 2, and step 3), the solvent used for cleaning may be recovered to confirm the amount of components derived from the residue contained in the solvent. The confirmation method is not particularly limited, and can be selected depending on the component to be specified. Examples of the confirmation method include evaluation of remaining solvent by GC (gas chromatography), evaluation of the amount of remaining low molecular components by UV (ultraviolet) irradiation evaluation, evaluation of the amount of remaining polymer by GPC (gel permeation chromatography), evaluation of the number of contained particles by a liquid particle counter, evaluation of the metal content by ICP-MS (inductively coupled plasma mass spectrometry), and evaluation by applying a cleaning solvent to a wafer and performing a defect inspection.

[0066] <Process 4, Process 5> In particular, in the present cleaning method, it is preferable to carry out the following steps 4 and 5 after carrying out each cleaning step. Step 4: A step of applying at least one of the solvents used in steps 1 and 2 (or steps 1 to 3) onto the substrate using a resist application device. Step 5: After step 4, a step of measuring the number of defects on the substrate using a defect inspection device. If the number of defects measured in step 5 exceeds a reference value, it is preferable to carry out at least one step selected from the group consisting of steps 1 and 2 (or steps 1 to 3) again. The above steps 4 and 5 make it possible to confirm the results of removing residues from inside the coating apparatus by the cleaning step using the solvent to be measured. Furthermore, by repeatedly performing at least one of steps 1 and 2 (or steps 1 to 3) (more preferably both steps 1 and 2 (or all steps 1 to 3)) until the number of defects measured in step 5 falls below a reference value, it is possible to more reliably suppress the occurrence of defects in the resist film formed using the resist composition to be next coated using the coating apparatus.

[0067] The substrate used in step 4 may be a substrate used in the manufacture of integrated circuit devices, and is preferably a silicon wafer. The inspection accuracy is further improved by reducing the number of defects (preferably the number of defects with a size of 19 nm or more) on the substrate before applying step 4 to 1.20 / cm 2 The substrate is preferably 0.75 particles / cm or less. 2 More preferably, the substrate has a lower limit of 0.00 particles / cm. 2 That's all. The number of defects on the substrate before it is subjected to step 4 and the number of defects on the substrate in step 5 can be measured using a defect inspection device (for example, a dark-field defect inspection device SP5 manufactured by KLA Tencor Corporation).

[0068] The application of the solvent in step 4 is carried out using the application device, which has already been described. The amount of the solvent supplied (coating amount) to the substrate is preferably 0.2 to 10.0 mL / s, more preferably 0.5 to 3.0 mL / s The time for supplying the solvent is preferably 3 to 300 seconds, more preferably 5 to 60 seconds. In step 4, after the solvent is applied onto the substrate, the substrate is preferably dried. An example of a drying method is a method of drying by heating. Heating can be performed by a means provided in a normal exposure machine and / or a developing machine, and may be performed using a hot plate or the like. The heating temperature is preferably 80 to 250°C, more preferably 80 to 140°C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds. In one embodiment, heating at 100°C for 60 seconds is preferred.

[0069] The number of defects on the substrate coated with the solvent in step 5 is measured using a defect inspection device. The size of the defects to be measured is not particularly limited, but it is preferable to measure the number of defects having a size of 19 nm or more in terms of better inspection accuracy. By carrying out the above step 5, the number of defects present on the substrate after application of the solvent is measured.

[0070] When comparing the number of defects measured in step 5 with a standard value, it is preferable to use the increase in the number of defects calculated by subtracting the number of defects present on the substrate before the solvent was applied in step 4, which was previously measured, from the number of defects measured in step 5, as the number of defects caused by the solvent used for cleaning for the comparison. The reference value in step 5 is set appropriately depending on conditions such as the configuration of the resist coating equipment, the composition of the resist composition, and the precision required for the resist pattern to be formed. When the number of defects measured in step 5 (preferably the number of defects caused by the solvent calculated by the above method) is large, it suggests the possibility that residues adhering to the liquid-contacting parts of the coating device remain. If residues remain, they may be mixed into new resist composition supplied by the coating device, causing defects in the formed resist film.

[0071] Therefore, when the number of defects exceeds the reference value, it is preferable to repeat at least one step selected from the group consisting of steps 1 and 2 (or steps 1 to 3). Of these, it is more preferable to repeat both steps 1 and 2. It is preferable to perform the above steps 1 and 2 (or steps 1 to 3) again on the coating apparatus, and then perform the above steps 4 and 5 again. It is more preferable to repeat either steps 1 and 2 (or steps 1 to 3), and steps 4 and 5 until the number of defects measured in step 5 falls below the reference value.

[0072] The present cleaning method is preferably carried out in a clean room. The cleanliness level is preferably class 6 or less, more preferably class 5 or less, and even more preferably class 4 or less, according to the international standard ISO 14644-1.

[0073] The resist coating apparatus cleaned by the present cleaning method is used to coat a substrate surface with a resist composition. Hereinafter, the resist composition used in the resist coating apparatus cleaned by the present cleaning method will be described, followed by a method of coating the resist composition by the resist coating apparatus.

[0074] [Composition of the resist composition] There are no particular limitations on the components contained in the resist composition, but it is preferable for the composition to contain a resin (preferably a resin whose polarity increases under the action of an acid), a photoacid generator, and a solvent. The components contained in the resist composition will be described in detail below.

[0075] <Resin> The resist composition may contain a resin. The resin is preferably a resin whose polarity increases under the action of an acid (hereinafter also referred to as "resin (A)"). It is preferable that the resin does not have a repeating unit having a silicon atom, but has a repeating unit derived from a monomer having a (meth)acrylic group.

[0076] The resin (A) preferably has a repeating unit (Aa) having an acid-decomposable group (hereinafter also simply referred to as "repeating unit (Aa)"). The acid decomposable group refers to a group that decomposes under the action of an acid to generate a polar group. The acid decomposable group preferably has a structure in which a polar group is protected by a leaving group that is released under the action of an acid. That is, the resin (A) has a repeating unit (Aa) that has a group that decomposes under the action of an acid to generate a polar group. The resin having this repeating unit (Aa) has increased polarity under the action of an acid, and its solubility in an alkaline developer increases and its solubility in an organic solvent decreases.

[0077] The polar group is preferably an alkali-soluble group, and examples thereof include acidic groups such as a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (alkylsulfonyl)(alkylcarbonyl)imide group, a bis(alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imide group, a bis(alkylsulfonyl)methylene group, a bis(alkylsulfonyl)imide group, a tris(alkylcarbonyl)methylene group, and a tris(alkylsulfonyl)methylene group, as well as an alcoholic hydroxyl group. Among these, the polar group is preferably a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

[0078] Examples of the leaving group which is eliminated by the action of an acid include groups represented by the formulae (Y1) to (Y4). Formula (Y1):-C(Rx1)(Rx2)(Rx3) Formula (Y2):-C(=O)OC(Rx1)(Rx2)(Rx3) Formula (Y3):-C(R 36 )(R 37 )(OR 38 ) Formula (Y4):-C(Rn)(H)(Ar)

[0079] In formula (Y1) and formula (Y2), Rx1 to Rx3 each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), or an aryl group (monocyclic or polycyclic). When all of Rx1 to Rx3 are alkyl groups (linear or branched), it is preferable that at least two of Rx1 to Rx3 are methyl groups. In particular, it is preferable that Rx1 to Rx3 each independently represent a linear or branched alkyl group, and it is more preferable that Rx1 to Rx3 each independently represent a linear alkyl group. Two of Rx1 to Rx3 may be bonded to form a monocycle or polycycle. The alkyl group of Rx1 to Rx3 is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. As the cycloalkyl group of Rx1 to Rx3, a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, and a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are preferable. The aryl group of Rx1 to Rx3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. The alkenyl group of Rx1 to Rx3 is preferably a vinyl group. The cycloalkyl group formed by combining two of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms. In the cycloalkyl group formed by combining two of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, or a group having a heteroatom such as a carbonyl group. In the group represented by formula (Y1) or formula (Y2), for example, it is preferable that Rx1 is a methyl group or an ethyl group, and Rx2 and Rx3 are bonded to form the above-mentioned cycloalkyl group. When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the alkyl group, cycloalkyl group, alkenyl group, aryl group represented by Rx1 to Rx3, and the ring formed by bonding two of Rx1 to Rx3 further have a fluorine atom or an iodine atom as a substituent.

[0080] In formula (Y3), R 36 ~R 38 R each independently represents a hydrogen atom or a monovalent substituent. 37 and R 38 may be bonded to each other to form a ring. Examples of the monovalent substituent include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. R 36 It is also preferred that is a hydrogen atom.

[0081] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0082] [ka]

[0083] Here, L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining these (for example, a group formed by combining an alkyl group with an aryl group). M represents a single bond or a divalent linking group. Q represents an alkyl group which may have a heteroatom, a cycloalkyl group which may have a heteroatom, an aryl group which may have a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group combining these (for example, a group combining an alkyl group and a cycloalkyl group). The alkyl and cycloalkyl groups may, for example, have one of the methylene groups replaced with a heteroatom such as an oxygen atom or a group containing a heteroatom such as a carbonyl group. It is preferable that one of L1 and L2 is a hydrogen atom, and the other is an alkyl group, a cycloalkyl group, an aryl group, or a combination of an alkylene group and an aryl group. At least two of Q, M and L1 may be bonded to form a ring (preferably a 5- or 6-membered ring). From the viewpoint of fine patterning, L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Examples of secondary alkyl groups include isopropyl, cyclohexyl, and norbornyl groups, and examples of tertiary alkyl groups include tert-butyl and adamantane ring groups. In these embodiments, Tg (glass transition temperature) and activation energy are high, so that the film strength is ensured and fogging can be suppressed.

[0084] In formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is more preferably an aryl group.

[0085] The repeating unit (Aa) is also preferably a repeating unit represented by formula (A).

[0086] [ka]

[0087] L1 represents a divalent linking group which may have a fluorine atom or an iodine atom, R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom, and R2 represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom, provided that at least one of L1, R1, and R2 has a fluorine atom or an iodine atom. L1 represents a divalent linking group which may have a fluorine atom or an iodine atom. Examples of the divalent linking group which may have a fluorine atom or an iodine atom include -CO-, -O-, -S-, -SO-, -SO2-, a hydrocarbon group which may have a fluorine atom or an iodine atom (e.g., an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, etc.), and a linking group in which a plurality of these are linked together. Among these, in terms of the effect of the present invention being more excellent, L1 is preferably -CO- or -arylene group-alkylene group having a fluorine atom or an iodine atom-. The arylene group is preferably a phenylene group. The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkylene group having a fluorine atom or an iodine atom is not particularly limited, but in terms of better effects of the present invention, it is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0088] R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. The alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom is not particularly limited, but in terms of better effects of the present invention, it is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. The alkyl group may have a heteroatom other than the halogen atom, such as an oxygen atom.

[0089] R2 represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom. The leaving group includes groups represented by the formulae (Z1) to (Z4). Formula (Z1):-C(Rx 11 )(Rx 12 )(Rx 13 ) Formula (Z2):-C(=O)OC(Rx 11 )(Rx 12 )(Rx 13 ) Formula (Z3):-C(R 136 )(R 137 )(OR 138 ) Formula (Z4):-C(Rn1)(H)(Ar1)

[0090] In formula (Z1) and formula (Z2), Rx 11 ~Rx 13 Each of Rx independently represents an alkyl group (linear or branched) which may have a fluorine atom or an iodine atom, or a cycloalkyl group (monocyclic or polycyclic) which may have a fluorine atom or an iodine atom. 11 ~Rx 13 When all of are alkyl groups (linear or branched), Rx 11 ~Rx 13 At least two of these are preferably methyl groups. Rx 11 ~Rx 13 are the same as Rx1 to Rx3 in the above-mentioned formulas (Y1) and (Y2), except that they may have a fluorine atom or an iodine atom, and have the same definitions and preferred ranges as the alkyl group and cycloalkyl group.

[0091] In formula (Z3), R 136 ~R 138 R each independently represents a hydrogen atom or a monovalent substituent which may have a fluorine atom or an iodine atom. 137 and R 138may be bonded to each other to form a ring. Examples of the monovalent substituent which may have a fluorine atom or an iodine atom include an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, an aralkyl group which may have a fluorine atom or an iodine atom, and groups which combine these (for example, a group which combines an alkyl group and a cycloalkyl group). The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom in addition to a fluorine atom and an iodine atom. That is, the alkyl group, cycloalkyl group, aryl group, and aralkyl group may have, for example, one methylene group replaced with a heteroatom such as an oxygen atom or a group having a heteroatom such as a carbonyl group.

[0092] Formula (Z3) is preferably a group represented by the following formula (Z3-1).

[0093] [ka]

[0094] Here, L 11 and L 12 each independently represents a hydrogen atom; an alkyl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom; a cycloalkyl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom; an aryl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom; or a group combining these (for example, a group combining an alkyl group and a cycloalkyl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom). M1 represents a single bond or a divalent linking group. Q1 represents an alkyl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom; a cycloalkyl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom; an aryl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom; an amino group; an ammonium group; a mercapto group; a cyano group; an aldehyde group; or a group combining these (for example, a group combining an alkyl group and a cycloalkyl group which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom).

[0095] In formula (Z4), Ar1 represents an aromatic ring group which may have a fluorine atom or an iodine atom. Rn1 represents an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. Rn1 and Ar1 may be bonded to each other to form a non-aromatic ring.

[0096] The repeating unit (Aa) is also preferably a repeating unit represented by formula (AI).

[0097] [ka]

[0098] In general formula (AI), Xa1 represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Rx1 to Rx3 each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), or an aryl group (monocyclic or polycyclic). However, when all of Rx1 to Rx3 are alkyl groups (linear or branched), it is preferable that at least two of Rx1 to Rx3 are methyl groups. Two of Rx1 to Rx3 may be bonded to form a cycloalkyl group (monocyclic or polycyclic).

[0099] The alkyl group represented by Xa1, which may have a substituent, is, for example, a methyl group or -CH2-R 11 Examples of the group represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group or a monovalent substituent, and examples thereof include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0100] Examples of the divalent linking group for T include an alkylene group, an aromatic ring group, a -COO-Rt- group, and a -O-Rt- group, in which Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH2- group, a -(CH2)2- group, or a -(CH2)3- group.

[0101] The alkyl group of Rx1 to Rx3 is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The cycloalkyl group of Rx1 to Rx3 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. The aryl group of Rx1 to Rx3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. The alkenyl group of Rx1 to Rx3 is preferably a vinyl group. The cycloalkyl group formed by combining two of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, and is preferably a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. Among them, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is preferable. In the cycloalkyl group formed by combining two of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, or a group having a heteroatom such as a carbonyl group. In the repeating unit represented by general formula (AI), for example, Rx1 is preferably a methyl group or an ethyl group, and Rx2 and Rx3 are bonded to form the above-mentioned cycloalkyl group.

[0102] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms), etc. The number of carbon atoms in the substituent is preferably 8 or less.

[0103] The repeating unit represented by general formula (AI) is preferably an acid-decomposable (meth)acrylic acid tertiary alkyl ester repeating unit (a repeating unit in which Xa1 represents a hydrogen atom or a methyl group and T represents a single bond).

[0104] The resin (A) may have one type of repeating unit (Aa) alone, or may have two or more types. The content of the repeating unit (Aa) (the total content when two or more kinds of repeating units (Aa) are present) is preferably 15 to 80 mol %, more preferably 20 to 70 mol %, based on the total repeating units in the resin (A).

[0105] The resin (A) preferably has, as the repeating unit (Aa), at least one repeating unit selected from the group consisting of repeating units represented by the following general formulas (A-VIII) to (A-XII).

[0106] [ka]

[0107] In general formula (A-VIII), R5 represents a tert-butyl group or a -CO-O-(tert-butyl) group. In formula (A-IX), R6 and R7 each independently represent a monovalent substituent. Examples of the monovalent substituent include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. In formula (AX), p represents 1 to 5, and is preferably 1 or 2. In the general formulae (AX) to (A-XII), R8 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R9 represents an alkyl group having 1 to 3 carbon atoms. In general formula (A-XII), R 10 represents an alkyl group having 1 to 3 carbon atoms or an adamantyl group.

[0108] (Repeating unit having an acid group) The resin (A) may have a repeating unit having an acid group. The acid group is preferably an acid group having a pKa of not more than 13. The acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and even more preferably 5 to 10, as described above. When the acid decomposable resin has an acid group with a pKa of 13 or less, the content of the acid group in the acid decomposable resin is not particularly limited, but is often 0.2 to 6.0 mmol / g. Among them, 0.8 to 6.0 mmol / g is preferable, 1.2 to 5.0 mmol / g is more preferable, and 1.6 to 4.0 mmol / g is even more preferable. If the content of the acid group is within the above range, development proceeds well, and the formed pattern shape is excellent, and the resolution is also excellent. The acid group is preferably, for example, a carboxyl group, a hydroxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, or a sulfonamide group. In addition, the above hexafluoroisopropanol group is preferably a group in which one or more (preferably one or two) fluorine atoms are substituted with a group other than a fluorine atom. Examples of such groups include a group containing -C(CF3)(OH)-CF2-. The above group containing -C(CF3)(OH)-CF2- may be a ring group containing -C(CF3)(OH)-CF2-. The repeating unit having an acid group is preferably a repeating unit represented by the following formula (B).

[0109] [ka]

[0110] R3 represents a hydrogen atom, or a monovalent substituent which may have a fluorine atom or an iodine atom. The monovalent substituent which may have a fluorine atom or an iodine atom is preferably a group represented by -L4-R8. L4 represents a single bond or an ester group. R8 may be an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, or a group which combines these.

[0111] R4 and R5 each independently represent a hydrogen atom, a fluorine atom, an iodine atom, or an alkyl group which may have a fluorine atom or an iodine atom.

[0112] L2 represents a single bond or an ester group. L3 represents an aromatic hydrocarbon ring group having a valence of (n+m+1) or an alicyclic hydrocarbon ring group having a valence of (n+m+1). Examples of the aromatic hydrocarbon ring group include a benzene ring group and a naphthalene ring group. Examples of the alicyclic hydrocarbon ring group include a monocyclic or polycyclic ring group, such as a cycloalkyl ring group. R6 represents a hydroxyl group or a fluorinated alcohol group (preferably a hexafluoroisopropanol group). When R6 is a hydroxyl group, L3 is preferably an aromatic hydrocarbon ring group having a valence of (n+m+1). R7 represents a halogen atom, including a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. m represents an integer of 1 or more. m is preferably an integer of 1 to 3, and more preferably an integer of 1 to 2. n represents an integer of 0 or greater than 1. n is preferably an integer of 1 to 4. Incidentally, (n+m+1) is preferably an integer of 1 to 5.

[0113] As the repeating unit having an acid group, a repeating unit represented by the following general formula (I) is also preferred.

[0114] [ka]

[0115] In general formula (I), R 41 , R 42 and R 43 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. 42 may be bonded to Ar4 to form a ring, in which case R 42 represents a single bond or an alkylene group. 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 bonds with the ring, it represents an (n+2)-valent aromatic ring group. n represents an integer of 1 to 5.

[0116] R in general formula (I) 41 , R 42 , and R 43 As the alkyl group, an alkyl group having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, or a dodecyl group, is preferable, an alkyl group having 8 or less carbon atoms is more preferable, and an alkyl group having 3 or less carbon atoms is even more preferable.

[0117] R in general formula (I) 41 , R 42 , and R 43 The cycloalkyl group may be a monocyclic or polycyclic group, and among these, a monocyclic cycloalkyl group having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group, is preferred. R in general formula (I) 41 , R 42 , and R 43 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. R in general formula (I) 41 , R 42 , and R 43 The alkyl group contained in the alkoxycarbonyl group of R 41 , R 42 , R 43 The same alkyl groups as those in the above are preferred.

[0118] Ar4 represents an aromatic ring group having a valence of (n+1). When n is 1, the divalent aromatic ring group may have a substituent, and is preferably an arylene group having 6 to 18 carbon atoms, such as a phenylene group, a tolylene group, a naphthylene group, or an anthracenylene group, or an aromatic ring group containing a heterocycle, such as a thiophene ring, a furan ring, a pyrrole ring, a benzothiophene ring, a benzofuran ring, a benzopyrrole ring, a triazine ring, an imidazole ring, a benzimidazole ring, a triazole ring, a thiadiazole ring, or a thiazole ring.

[0119] Specific examples of the (n+1)-valent aromatic ring group when n is an integer of 2 or more include groups obtained by removing any (n-1) hydrogen atoms from the above-mentioned specific examples of the divalent aromatic ring group. The (n+1)-valent aromatic ring group may further have a substituent.

[0120] 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 R 41 , R 42 , and R 43 Examples of the alkyl group include the alkyl groups listed above, alkoxy groups such as a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, and a butoxy group; and aryl groups such as a phenyl group. -CONR represented by X4 64 -(R 64 represents a hydrogen atom or an alkyl group) 64 Examples of the alkyl group include alkyl groups having 20 or less carbon atoms, such as 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, and an alkyl group having 8 or less carbon atoms is preferred. X4 is preferably a single bond, -COO- or -CONH-, more preferably a single bond or -COO-.

[0121] The alkylene group in L4 is preferably an alkylene group having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group. Ar4 is preferably an aromatic ring group having 6 to 18 carbon atoms, and more preferably a benzene ring group, a naphthalene ring group, or a biphenylene ring group.

[0122] Specific examples of the repeating unit represented by formula (I) are shown below, but the present invention is not limited thereto. In the formula, a represents 1 or 2.

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] (Repeating unit (A-1) derived from hydroxystyrene) The resin (A) preferably has a repeating unit (A-1) derived from hydroxystyrene as a repeating unit having an acid group. An example of the repeating unit (A-1) derived from hydroxystyrene is a repeating unit represented by the following general formula (1).

[0127] [ka]

[0128] In general formula (1), A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group. R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group, or an aryloxycarbonyl group, and when there are a plurality of R, they may be the same or different. When there are a plurality of R, they may be combined together to form a ring. R is preferably a hydrogen atom. a represents an integer of 1 to 3, and b represents an integer of 0 to (5-a).

[0129] The repeating unit (A-1) is preferably a repeating unit represented by the following general formula (AI).

[0130] [ka]

[0131] The resist composition containing the resin (A) having the repeating unit (A-1) is preferably used for KrF exposure, EB exposure, or EUV exposure. In this case, the content of the repeating unit (A-1) is preferably 30 to 100 mol %, more preferably 40 to 100 mol %, and even more preferably 50 to 100 mol %, based on the total repeating units in the resin (A).

[0132] (Repeating unit (A-2) having at least one structure selected from the group consisting of a lactone structure, a sultone structure, a carbonate structure, and a hydroxyadamantane structure) The resin (A) may have a repeating unit (A-2) having at least one structure selected from the group consisting of a lactone structure, a carbonate structure, a sultone structure, and a hydroxyadamantane structure.

[0133] The lactone structure or sultone structure in the repeating unit having a lactone structure or a sultone structure is not particularly limited, but is preferably a 5- to 7-membered ring lactone structure or a 5- to 7-membered ring sultone structure, and more preferably a 5- to 7-membered ring lactone structure to which another ring structure is condensed in the form of a bicyclo structure or a spiro structure, or a 5- to 7-membered ring sultone structure to which another ring structure is condensed in the form of a bicyclo structure or a spiro structure. Examples of the repeating unit having a lactone structure or a sultone structure include the repeating units described in paragraphs 0094 to 0107 of WO 2016 / 136354.

[0134] The resin (A) may have a repeating unit having a carbonate structure. The carbonate structure is preferably a cyclic carbonate ester structure. Examples of the repeating unit having a carbonate structure include the repeating units described in paragraphs 0106 to 0108 of WO 2019 / 054311.

[0135] The resin (A) may have a repeating unit having a hydroxyadamantane structure. Examples of the repeating unit having a hydroxyadamantane structure include the repeating unit represented by the following general formula (AIIa).

[0136] [ka]

[0137] In general formula (AIIa), R1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. R2c to R4c each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R2c to R4c represents a hydroxyl group. It is preferable that one or two of R2c to R4c are a hydroxyl group, and the remaining are hydrogen atoms.

[0138] (Repeating units having fluorine or iodine atoms) The resin (A) may have a repeating unit having a fluorine atom or an iodine atom. Examples of the repeating unit having a fluorine atom or an iodine atom include the repeating units described in paragraphs 0080 to 0081 of JP2019-045864A.

[0139] (Repeating unit having a photoacid generating group) The resin (A) may contain, as a repeating unit other than the above, a repeating unit having a group that generates an acid upon irradiation with radiation. An example of such a repeating unit is a repeating unit represented by the following formula (4).

[0140] [ka]

[0141] R 41 represents a hydrogen atom or a methyl group. 41 represents a single bond or a divalent linking group. 42 R represents a divalent linking group. 40 represents a structural portion that is decomposed by irradiation with actinic rays or radiation to generate an acid in the side chain. Examples of the repeating unit having a photoacid generating group are shown below.

[0142] [ka] JPEG0007654430000024.jpg4240

[0143] Other examples of the repeating unit represented by formula (4) include the repeating units described in paragraphs

[0094] to

[0105] of JP2014-041327A and the repeating unit described in paragraph

[0094] of WO2018 / 193954A.

[0144] The content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 2 mol% or more, based on the total repeating units in the acid-decomposable resin, and the upper limit is preferably 20 mol% or less, more preferably 10 mol% or less, and even more preferably 5 mol% or less. Examples of the repeating unit having a photoacid generating group include the repeating units described in paragraphs 0092 to 0096 of JP2019-045864A.

[0145] (Repeating unit having an alkali-soluble group) The resin (A) may have a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulfonylimide group, and an aliphatic alcohol group substituted at the α-position with an electron-withdrawing group (for example, a hexafluoroisopropanol group), with the carboxyl group being preferred. When the resin (A) contains a repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. Examples of the repeating unit having an alkali-soluble group include a repeating unit having an alkali-soluble group bonded directly to the main chain of a resin, such as a repeating unit of acrylic acid or methacrylic acid, or a repeating unit having an alkali-soluble group bonded to the main chain of a resin via a linking group, which may have a monocyclic or polycyclic cyclic hydrocarbon structure. The repeating unit having an alkali-soluble group is preferably a repeating unit derived from acrylic acid or methacrylic acid.

[0146] (Repeating unit having neither an acid-decomposable group nor a polar group) The resin (A) may further have a repeating unit having neither an acid-decomposable group nor a polar group. The repeating unit having neither an acid-decomposable group nor a polar group preferably has an alicyclic hydrocarbon.

[0147] Examples of the repeating unit having neither an acid-decomposable group nor a polar group include the repeating units described in paragraphs

[0236] to

[0237] of U.S. Patent Application Publication No. 2016 / 0026083 and the repeating unit described in paragraph

[0433] of U.S. Patent Application Publication No. 2016 / 0070167.

[0148] In addition to the above repeating structural units, the resin (A) may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like.

[0149] (Characteristics of Resin (A)) It is preferable that all of the repeating units of the resin (A) are derived from a compound having an ethylenically unsaturated bond. In particular, it is preferable that all of the repeating units of the resin (A) are derived from a (meth)acrylate monomer (a monomer having a (meth)acrylic group). In this case, any of the following resins can be used: one in which all of the repeating units are derived from a methacrylate monomer, one in which all of the repeating units are derived from an acrylate monomer, or one in which all of the repeating units are derived from a methacrylate monomer and an acrylate monomer. It is preferable that the repeating units derived from an acrylate monomer are 50 mol % or less of the total repeating units in the resin (A).

[0150] When the resist composition is for argon fluoride (ArF) exposure, from the viewpoint of the transmittance of ArF light, it is preferable that the resin (A) does not substantially have an aromatic group. More specifically, the repeating unit having an aromatic group is preferably 5 mol % or less, more preferably 3 mol % or less, based on the total repeating units of the resin (A), and ideally, it is 0 mol %, that is, it is even more preferable that the resin (A) has no repeating units having an aromatic group. Furthermore, when the resist composition is for ArF exposure, the resin (A) preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure, and preferably contains neither fluorine atoms nor silicon atoms.

[0151] When the resist composition is for krypton fluoride (KrF) exposure, EB exposure, or EUV exposure, the resin (A) preferably has a repeating unit having an aromatic hydrocarbon group, and more preferably has a repeating unit having a phenolic hydroxyl group. Examples of the repeating unit having a phenolic hydroxyl group include the repeating unit (A-1) derived from hydroxystyrene and a repeating unit derived from hydroxystyrene (meth)acrylate. Furthermore, when the resist composition is for KrF exposure, EB exposure, or EUV exposure, it is also preferable that the resin (A) has a repeating unit having a structure in which the hydrogen atom of a phenolic hydroxyl group is protected with a group (leaving group) that decomposes and leaves under the action of an acid. When the resist composition is for KrF exposure, EB exposure, or EUV exposure, the content of repeating units having an aromatic hydrocarbon group contained in the resin (A) is preferably 30 to 100 mol %, more preferably 40 to 100 mol %, and even more preferably 50 to 100 mol %, based on all repeating units in the resin (A).

[0152] The resin (A) can be synthesized according to a conventional method (for example, radical polymerization). The weight average molecular weight (Mw) of the resin (A) is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 5,000 to 15,000. By making the weight average molecular weight (Mw) of the resin (A) 1,000 to 200,000, it is possible to prevent deterioration of heat resistance and dry etching resistance, and further to prevent deterioration of developability and deterioration of film formability due to high viscosity. The weight average molecular weight (Mw) of the resin (A) is a polystyrene equivalent value measured by the above-mentioned GPC method. The polydispersity (molecular weight distribution) of the resin (A) is usually 1 to 5, preferably 1 to 3, and more preferably 1.1 to 2.0. The smaller the polydispersity, the better the resolution and resist shape, and further the smoother the sidewalls of the pattern and the better the roughness.

[0153] In the resist composition, the content of the resin (A) is preferably from 50 to 99.9 mass %, and more preferably from 60 to 99.0 mass %, based on the total solid content of the resist composition. The resin (A) may be used alone or in combination of two or more kinds. In this specification, the term "solid content" refers to components that can constitute a resist film, excluding the solvent. Even if the above components are in a liquid state, they are considered to be solid contents.

[0154] <Photoacid generator (B)> The resist composition may contain a photoacid generator (B). There are no particular limitations on the photoacid generator (B) as long as it is a compound that generates an acid when irradiated with radiation. The photoacid generator (B) may be in the form of a low molecular weight compound, or may be incorporated into a part of a polymer. In addition, the form of a low molecular weight compound and the form of being incorporated into a part of a polymer may be used in combination. When the photoacid generator (B) is in the form of a low molecular weight compound, the weight average molecular weight (Mw) is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less. When the photoacid generator (B) is in a form in which it is incorporated into a part of a polymer, it may be incorporated into a part of the resin (A) or into a resin different from the resin (A). In the present invention, the photoacid generator (B) is preferably in the form of a low molecular weight compound. The photoacid generator (B) is not particularly limited as long as it is a known compound, but is preferably a compound that generates an organic acid upon irradiation with radiation, and more preferably a photoacid generator having a fluorine atom or iodine atom in the molecule. Examples of the organic acid include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimide acids, bis(alkylsulfonyl)imide acids, and tris(alkylsulfonyl)methide acids.

[0155] The volume of the acid generated by the photoacid generator (B) is not particularly limited. However, in order to suppress the diffusion of the acid generated by exposure to the non-exposed area and to improve the resolution, it is preferable that the volume of the acid be 240 Å or less. 3 More than 305 Å is preferable. 3 More preferably, 350 Å or more 3 More preferably, 400 Å or more. 3 From the viewpoint of sensitivity or solubility in a coating solvent, the volume of the acid generated by the photoacid generator (B) is preferably 1,500 Å or less. 3 Preferably less than 1000 Å 3 Less than 700 Å is more preferable. 3 The following is even more preferred: The volume values ​​are calculated using "WinMOPAC" manufactured by Fujitsu Ltd. In calculating the volume values, first, the chemical structure of the acid in each example is input, then, using this structure as the initial structure, the most stable conformation of each acid is determined by molecular force field calculation using the MM (Molecular Mechanics)3 method, and then, the "accessible volume" of each acid can be calculated by performing molecular orbital calculations using the PM (Parameterized Model number)3 method for these most stable conformations.

[0156] The structure of the acid generated by the photoacid generator (B) is not particularly limited, but in terms of suppressing the diffusion of the acid and improving the resolution, it is preferable that the interaction between the acid generated by the photoacid generator (B) and the resin (A) is strong. From this point of view, when the acid generated by the photoacid generator (B) is an organic acid, it is preferable that it further has a polar group in addition to organic acid groups such as a sulfonic acid group, a carboxylic acid group, a carbonylsulfonylimide acid group, a bissulfonylimide acid group, and a trisulfonylmethide acid group. Examples of the polar group include an ether group, an ester group, an amide group, an acyl group, a sulfo group, a sulfonyloxy group, a sulfonamide group, a thioether group, a thioester group, a urea group, a carbonate group, a carbamate group, a hydroxyl group, and a mercapto group. The number of polar groups possessed by the generated acid is not particularly limited, and is preferably 1 or more, and more preferably 2 or more. However, from the viewpoint of suppressing excessive development, the number of polar groups is preferably less than 6, and more preferably less than 4.

[0157] Among these, in terms of obtaining a more excellent effect of the present invention, the photoacid generator (B) is preferably a photoacid generator having an anion moiety and a cation moiety. Examples of the photoacid generator (B) include the photoacid generators described in paragraphs 0144 to 0173 of JP2019-045864A.

[0158] The content of the photoacid generator (B) is not particularly limited, but in terms of providing better effects for the present invention, it is preferably 5 to 50 mass %, more preferably 10 to 40 mass %, and even more preferably 10 to 35 mass %, relative to the total solid content of the resist composition. The photoacid generator (B) may be used alone or in combination of two or more. When two or more photoacid generators (B) are used in combination, the total amount thereof is preferably within the above range.

[0159] The resist composition may contain, as the photoacid generator (B), the specific photoacid generators defined by the compounds (I) and (II).

[0160] (Compound (I)) Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing a first acidic moiety derived from the structural moiety X and a second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation. Structural part X: Anion part A1 - and cationic moiety M1 +and a structural portion that forms a first acidic site represented by HA1 upon irradiation with actinic rays or radiation. Structural site Y: Anionic site A2 - and cationic moiety M2 + and a structural portion that forms a second acidic site represented by HA2 upon exposure to actinic rays or radiation. However, compound (I) satisfies the following condition I.

[0161] Condition I: In the compound (I), the cationic moiety M1 in the structural moiety X + and the cationic moiety M2 in the structural moiety Y. + H + The compound PI, which is replaced by the cationic moiety M1 in the structural moiety X, + H + The acid dissociation constant a1 derived from the acidic moiety represented by HA1, which is replaced by the cationic moiety M2 in the structural moiety Y + H + and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0162] Condition I will be explained in more detail below. When compound (I) is, for example, a compound that generates an acid having one of the first acidic site derived from the structural site X and one of the second acidic site derived from the structural site Y, compound PI corresponds to a "compound having HA1 and HA2." More specifically, the acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI are determined as follows: - The pKa at which the compound has "A1 and HA2" is the acid dissociation constant a1, and the above "A1 - and HA2” is “A1 - and A2 - The pKa at which the compound becomes "a compound having the formula (I)" is the acid dissociation constant a2.

[0163] When the compound (I) is a compound that generates an acid having, for example, two of the first acidic sites derived from the structural site X and one of the second acidic sites derived from the structural site Y, the compound PI corresponds to a "compound having two HA1s and one HA2". When the acid dissociation constant of such a compound PI is determined, when the compound PI becomes a "compound having one A1 - and one HA1 and one HA2", the acid dissociation constant, and "one A1 - and one HA1 and one HA2" becomes "two A1s - and one HA2", the acid dissociation constant corresponds to the above-mentioned acid dissociation constant a1. Further, when "two A1s - and one HA2" becomes "two A1s - and A2 - having a compound", the acid dissociation constant corresponds to the acid dissociation constant a2. That is, in the case of such a compound PI, when there are a plurality of acid dissociation constants derived from the acidic site represented by HA1 in which the cation site M1 + in the structural site X is replaced by H + , the value of the acid dissociation constant a2 is larger than the largest value among the plurality of acid dissociation constants a1. When the acid dissociation constant when the compound PI becomes a "compound having one A1 - and one HA1 and one HA2" is aa, and "one A1 - and one HA1 and one HA2" becomes "two A1s - and one HA2", when the acid dissociation constant is ab, the relationship between aa and ab satisfies aa < ab.

[0164] The acid dissociation constant a1 and the acid dissociation constant a2 are determined by the method for measuring the acid dissociation constant described above. The above compound PI corresponds to the acid generated when the compound (I) is irradiated with actinic rays or radiation. When the compound (I) has two or more structural sites X, the structural sites X may be the same or different from each other. Also, two or more of the above A1s - , and two or more of the above M1s+ may be the same or different. In addition, in the compound (I), the above A1 - and A2 above - , and the above M1 + and M2 above + may be the same or different, but the above A1 - and A2 above - are preferably different from each other.

[0165] In order to obtain a more excellent LWR performance of the pattern to be formed, the difference between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 in the compound PI is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. The upper limit of the difference between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is not particularly limited, but is, for example, 16 or less.

[0166] In order to obtain a pattern with better LWR performance, the acid dissociation constant a2 in the compound PI is, for example, not more than 20, and preferably not more than 15. The lower limit of the acid dissociation constant a2 is preferably not less than −4.0.

[0167] In order to obtain a pattern with better LWR performance, the acid dissociation constant a1 of the compound PI is preferably not more than 2.0, and more preferably not more than 0. The lower limit of the acid dissociation constant a1 is preferably not less than −20.0.

[0168] Anion site A1 - and anion site A2 - is a structural moiety containing a negatively charged atom or atomic group, and examples thereof include structural moieties selected from the group consisting of the following formulae (AA-1) to (AA-3) and formulae (BB-1) to (BB-6). Anionic moiety A1 - As the anion moiety A2, those capable of forming an acidic moiety with a small acid dissociation constant are preferred, and among them, any of the formulae (AA-1) to (AA-3) is preferred. -As the anion site A1 - It is preferable that the compound is capable of forming an acidic site having a larger acid dissociation constant than the compound represented by the formula (BB-1) to the formula (BB-6), and is preferably selected from any of the formulae (AA-1) to (AA-3) and (BB-1) to (BB-6). In the following formulae (AA-1) to (AA-3) and (BB-1) to (BB-6), * indicates a bonding position. In formula (AA-2), R A R represents a monovalent organic group. A Examples of the monovalent organic group represented by the formula (I) include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0169] [ka] JPEG0007654430000026.jpg21139

[0170] In addition, the cationic moiety M1 + and cationic moiety M2 + is a structural moiety containing a positively charged atom or atomic group, and examples thereof include an organic cation having a monovalent charge. The organic cation is not particularly limited, but M in formula (Ia-1) described later is 11 + and M 12 + The organic cations may be the same as those represented by the following formula:

[0171] The specific structure of compound (I) is not particularly limited, and examples thereof include compounds represented by formulae (Ia-1) to (Ia-5) described below. First, the compound represented by formula (Ia-1) will be described below. The compound represented by formula (Ia-1) is as follows.

[0172] M 11 + A 11 - -L1-A 12 - M 12 + (Ia-1)

[0173] Compound (Ia-1) is capable of converting HA to HA when irradiated with actinic rays or radiation. 11 -L1-A 12 It produces the acid represented by H.

[0174] In formula (Ia-1), M 11 + and M 12 + each independently represents an organic cation. A 11 - and A 12 - each independently represents a monovalent anionic functional group. L1 represents a divalent linking group. M 11 + and M 12 + may be the same or different. A 11 - and A 12 - may be the same or different, but are preferably different from each other. In the above formula (Ia-1), M 11 + and M 12 + The organic cation represented by H + Compound PIa (HA 11 -L1-A 12 In H), A 12 The acid dissociation constant a2 derived from the acidic site represented by H is HA 11 The acid dissociation constant a1 derived from the acidic moiety represented by formula (Ia-1) is larger than the acid dissociation constant a1 derived from the acidic moiety represented by formula (Ia-1). The preferred values ​​of the acid dissociation constant a1 and the acid dissociation constant a2 are as described above. The acid generated from the compound PIa and the compound represented by formula (Ia-1) upon irradiation with actinic rays or radiation is the same. Also, M 11 + , M 12 + , A 11 - , A 12 -At least one of L1 and L2 may have an acid-decomposable group as a substituent.

[0175] In formula (Ia-1), M1 + and M2 + The organic cation represented by the formula (I) is as described later.

[0176] A 11 - The monovalent anionic functional group represented by the formula (I) is the above-mentioned anionic moiety A1 - Also, A is intended to mean a monovalent radical containing 12 - The monovalent anionic functional group represented by the above-mentioned anionic moiety A2 - is intended to mean a monovalent radical comprising: A 11 - and A 12 - The monovalent anionic functional group represented by the formula (AA-1) to (AA-3) and the formula (BB-1) to (BB-6) is preferably a monovalent anionic functional group containing an anionic moiety, and more preferably a monovalent anionic functional group selected from the group consisting of the formula (AX-1) to (AX-3) and the formula (BX-1) to (BX-7). 11 - Among them, the monovalent anionic functional group represented by formula (AX-1) to (AX-3) is preferable. 12 - Of the monovalent anionic functional groups represented by the formulae (BX-1) to (BX-7), monovalent anionic functional groups represented by the formulae (BX-1) to (BX-6) are preferred, and monovalent anionic functional groups represented by the formulae (BX-1) to (BX-7) are more preferred.

[0177] [ka]

[0178] In formulas (AX-1) to (AX-3), R A1 and R A2each independently represents a monovalent organic group. * represents a bonding site.

[0179] R A1 Examples of the monovalent organic group represented by the formula (I) include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0180] R A2 The monovalent organic group represented by the formula (I) is preferably a linear, branched, or cyclic alkyl group, or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and further preferably 1 to 6 carbon atoms. The alkyl group may have a substituent. The substituent is preferably a fluorine atom or a cyano group, more preferably a fluorine atom. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group.

[0181] The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may have a substituent. The substituent is preferably a fluorine atom, an iodine atom, a perfluoroalkyl group (for example, preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or a cyano group, and more preferably a fluorine atom, an iodine atom, or a perfluoroalkyl group.

[0182] In formulas (BX-1) to (BX-4) and (BX-6), R B represents a monovalent organic group. * represents the bonding position. R B The monovalent organic group represented by the formula (I) is preferably a linear, branched, or cyclic alkyl group, or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and further preferably 1 to 6 carbon atoms. The alkyl group may have a substituent. The substituent is not particularly limited, but is preferably a fluorine atom or a cyano group, more preferably a fluorine atom. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group. In addition, the carbon atom that is the bonding position in the alkyl group (for example, in the case of formulas (BX-1) and (BX-4), the carbon atom that is directly bonded to -CO- in the alkyl group in the formula corresponds, in the case of formulas (BX-2) and (BX-3), the carbon atom that is directly bonded to -SO2- in the alkyl group in the formula corresponds, and in the case of formula (BX-6), the carbon atom that is directly bonded to N in the alkyl group in the formula corresponds - In the case where R 1 has a substituent, the substituent is preferably a fluorine atom or a cyano group. In addition, the alkyl group may have a carbon atom substituted with a carbonyl carbon.

[0183] The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may have a substituent. The substituent is preferably a fluorine atom, an iodine atom, a perfluoroalkyl group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), a cyano group, an alkyl group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), an alkoxy group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or an alkoxycarbonyl group (e.g., preferably having 2 to 10 carbon atoms, more preferably having 2 to 6 carbon atoms), and more preferably a fluorine atom, an iodine atom, a perfluoroalkyl group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group.

[0184] In formula (Ia-1), the divalent linking group represented by L1 is not particularly limited, and may be -CO-, -NR-, -CO-, -O-, -S-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), a divalent aliphatic heterocyclic group (having at least one N atom, O atom, S atom, or Se atom in the ring structure), or Examples of R include a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, preferably a 5- to 7-membered ring, more preferably a 5- to 6-membered ring, divalent aromatic heterocyclic group (a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, preferably a 5- to 7-membered ring, more preferably a 5- to 6-membered ring), divalent aromatic hydrocarbon ring group (a 6- to 10-membered ring, more preferably a 6-membered ring), and a divalent linking group combining a plurality of these. The above R includes a hydrogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but for example, an alkyl group (preferably having 1 to 6 carbon atoms) is preferable. The alkylene group, the cycloalkylene group, the alkenylene group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon ring group may have a substituent, such as a halogen atom (preferably a fluorine atom).

[0185] The divalent linking group represented by L1 is preferably a divalent linking group represented by formula (L1).

[0186] [ka]

[0187] In formula (L1), L 111 represents a single bond or a divalent linking group. L 111The divalent linking group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -NH-, -O-, -SO-, -SO2-, an alkylene group which may have a substituent (preferably having 1 to 6 carbon atoms, and may be either linear or branched), a cycloalkylene group which may have a substituent (preferably having 3 to 15 carbon atoms), an aryl group which may have a substituent (preferably having 6 to 10 carbon atoms), and a divalent linking group which is a combination of a plurality of these. The substituent is not particularly limited, and examples thereof include a halogen atom, etc. p represents an integer of 0 to 3, and preferably an integer of 1 to 3. v represents an integer of 0 or 1. Each Xf1 independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. In addition, the alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Each Xf2 independently represents a hydrogen atom, an alkyl group which may have a fluorine atom as a substituent, or a fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, and more preferably 1 to 4. Among these, Xf2 preferably represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and more preferably a fluorine atom or a perfluoroalkyl group. Among them, Xf1 and Xf2 are each preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, and more preferably a fluorine atom or CF3. In particular, it is further preferable that both Xf1 and Xf2 are fluorine atoms. * indicates the bond position. L in formula (Ia-1) 11 represents a divalent linking group represented by formula (L1), L in formula (L1) 111 The bond (*) on the side of the A 12 - It is preferred to combine with

[0188] (Ia-1) 11 + and M12 + Preferred forms of the organic cation represented by the formula (I) will be described in detail. M 11 + and M 12 + Each of the organic cations represented by the formula (ZaI) (cation (ZaI)) or the organic cation represented by the formula (ZaII) (cation (ZaII)) is preferably independently an organic cation represented by the formula (ZaI) (cation (ZaII)).

[0189] [ka]

[0190] In the above formula (ZaI), R 201 , R 202 , and R 203 each independently represents an organic group. R 201 , R 202 , and R 203 The carbon number of the organic group represented by R is usually 1 to 30, and preferably 1 to 20. 201 ~R 203 Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. 201 ~R 203 Examples of groups formed by combining two of these include alkylene groups (such as butylene and pentylene groups) and -CH2-CH2-O-CH2-CH2-.

[0191] Suitable embodiments of the organic cation in formula (ZaI) include the cation (ZaI-1), cation (ZaI-2), an organic cation represented by formula (ZaI-3b) (cation (ZaI-3b)), and an organic cation represented by formula (ZaI-4b) (cation (ZaI-4b)), which will be described later.

[0192] First, the cation (ZaI-1) will be described. The cation (ZaI-1) is R201 ~R 203 is an arylsulfonium cation, in which at least one of the groups is an aryl group. The arylsulfonium cation is R 201 ~R 203 may all be aryl groups, or R 201 ~R 203 A part of the group may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group. Also, R 201 ~R 203 is an aryl group, and R 201 ~R 203 The remaining two of R may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. 201 ~R 203 Examples of groups formed by combining two of these groups include alkylene groups in which one or more methylene groups may be substituted with oxygen atoms, sulfur atoms, ester groups, amide groups, and / or carbonyl groups (e.g., butylene groups, pentylene groups, or -CH2-CH2-O-CH2-CH2-). Examples of arylsulfonium cations include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

[0193] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure with an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The alkyl group or cycloalkyl group that the arylsulfonium cation has as necessary is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.

[0194] R 201 ~R 203 The substituents which the aryl group, alkyl group and cycloalkyl group may have are each independently preferably an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 14 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom (e.g., fluorine, iodine), a hydroxyl group, a carboxyl group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, a phenylthio group and the like. The above-mentioned substituent may further have a substituent if possible. For example, it is also preferred that the above-mentioned alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group. It is also preferable that the above-mentioned substituents are combined in any desired manner to form an acid-decomposable group. The acid-decomposable group is intended to be a group that is decomposed by the action of an acid to generate an acid group, and is preferably a structure in which an acid group is protected by a leaving group that is eliminated by the action of an acid. The acid group and the leaving group are as described above.

[0195] Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is R in formula (ZaI). 201 ~R 203 are each independently a cation representing an organic group having no aromatic ring, where the aromatic ring includes an aromatic ring containing a heteroatom. R 201 ~R 203The organic group having no aromatic ring as the aromatic ring generally has 1 to 30 carbon atoms, and preferably has 1 to 20 carbon atoms. R 201 ~R 203 are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and further preferably a linear or branched 2-oxoalkyl group.

[0196] R 201 ~R 203 Examples of the alkyl group and cycloalkyl group include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups). R 201 ~R 203 may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. Also, R 201 ~R 203 It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0197] Next, the cation (ZaI-3b) will be described. The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0198] [ka]

[0199] In the formula (ZaI-3b), R 1c ~R 5ceach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. R 6c and R 7c each independently represents a hydrogen atom, an alkyl group (such as a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. R x and R y each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group. Also, R 1c ~R 7c , and R x and R y It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0200] R 1c ~R 5c Any two or more of the following, R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y may be bonded to each other to form a ring, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the ring include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocycles, and polycyclic condensed rings formed by combining two or more of these rings. Examples of the ring include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.

[0201] R 1c ~R 5c Any two or more of the following, R 6c and R 7c , and Rx and R y Examples of the group formed by bonding include alkylene groups such as butylene and pentylene, in which the methylene group may be substituted with a heteroatom such as an oxygen atom. R 5c and R 6c , and R 5c and R x The group formed by bonding is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.

[0202] R 1c ~R 5c , R 6c , R 7c , R x , R y , and R 1c ~R 5c Any two or more of the following, R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y The ring formed by bonding with each other may have a substituent.

[0203] Next, the cation (ZaI-4b) will be described. The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0204] [ka]

[0205] In the formula (ZaI-4b), l represents an integer of 0 to 2. r represents an integer of 0 to 8. R 13represents a hydrogen atom, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group having a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R 14 represents a hydroxyl group, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R 14 When a plurality of these are present, each independently represents the above group such as a hydroxyl group. R 15 Each of R independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. 15 may be bonded to each other to form a ring. 15 When R are bonded to each other to form a ring, the ring structure may contain heteroatoms such as oxygen atoms or nitrogen atoms. 15 are preferably alkylene groups and bonded to each other to form a ring structure. 15 The ring formed by bonding with each other may have a substituent.

[0206] In formula (ZaI-4b), R 13 , R 14 , and R 15 The alkyl group is linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like. Also, R 13 ~R 15 , and R x and R yIt is also preferred that each of the substituents independently form an acid-decomposable group by any combination of the substituents.

[0207] Next, formula (ZaII) will be described. In formula (ZaII), R 204 and R 205 each independently represents an aryl group, an alkyl group, or a cycloalkyl group. R 204 and R 205 The aryl group of R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. 204 and R 205 The aryl group may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, etc. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. R 204 and R 205 The alkyl group and cycloalkyl group are preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (for example, a cyclopentyl group, a cyclohexyl group, or a norbornyl group).

[0208] R 204 and R 205 The aryl group, alkyl group, and cycloalkyl group in R may each independently have a substituent. 204 and R 205 Examples of the substituent that the aryl group, alkyl group, and cycloalkyl group may have include an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 15 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group. 204 and R 205 It is also preferred that the substituents independently form an acid-decomposable group by any combination of the substituents.

[0209] Next, the compounds represented by formulas (Ia-2) to (Ia-4) will be described.

[0210] [ka]

[0211] In formula (Ia-2), A 21a - and A 21b - Each independently represents a monovalent anionic functional group. 21a - and A 21b - The monovalent anionic functional group represented by the formula (I) is the above-mentioned anionic moiety A1 - A is intended to include a monovalent radical comprising 21a - and A 21b - The monovalent anionic functional group represented by the formula (AX-1) to (AX-3) is not particularly limited, and examples thereof include monovalent anionic functional groups selected from the group consisting of the above-mentioned formulas (AX-1) to (AX-3). A 22 - represents a divalent anionic functional group. 22 - The divalent anionic functional group represented by the above-mentioned anionic moiety A2 - A divalent radical containing 22 - Examples of the divalent anionic functional group represented by the formula (BX-8) to (BX-11) shown below can be mentioned.

[0212] [ka]

[0213] M 21a + , M 21b + , and M 22 +Each independently represents an organic cation. 21a + , M 21b + , and M 22 + As the organic cation represented by the formula: + The same definition and preferred embodiments are also the same. L 21 and L 22 each independently represents a divalent organic group.

[0214] In addition, in the above formula (Ia-2), M 21a + , M 21b + , and M 22 + The organic cation represented by H + In compound PIa-2, A is replaced by 22 The acid dissociation constant a2 derived from the acidic site represented by H is A 21a Acid dissociation constants a1-1 and A 21b It is larger than the acid dissociation constant a1-2 derived from the acidic site represented by H. Note that the acid dissociation constant a1-1 and the acid dissociation constant a1-2 correspond to the above-mentioned acid dissociation constant a1. In addition, A 21a - and A 21b - may be the same or different. 21a + , M 21b + , and M 22 + may be the same or different from each other. Also, M 21a + , M 21b + , M 22 + , A 21a - , A 21b - , L 21 , and L 22 At least one of may have an acid-decomposable group as a substituent.

[0215] In formula (Ia-3), A 31a - and A 32 - Each independently represents a monovalent anionic functional group. 31a - The definition of the monovalent anionic functional group represented by the formula (Ia-2) is as follows: 21a - and A 21b - The same definition and preferred embodiments are also the same. A 32 - The monovalent anionic functional group represented by the above-mentioned anionic moiety A2 - A is intended to include a monovalent radical comprising 32 - The monovalent anionic functional group represented by the formula (BX-1) to (BX-7) is not particularly limited, and examples thereof include monovalent anionic functional groups selected from the group consisting of the above-mentioned formulas (BX-1) to (BX-7). A 31b - represents a divalent anionic functional group. 31b - The divalent anionic functional group represented by the formula (I) is the above-mentioned anionic moiety A1 - A divalent radical containing 31b - Examples of the divalent anionic functional group represented by the formula (AX-4) below include divalent anionic functional groups represented by the formula (AX-4) below.

[0216] [ka]

[0217] M 31a + , M 31b + , and M 32 + Each independently represents a monovalent organic cation. 31a + , M 31b + , and M32 + As the organic cation, the above-mentioned M1 + The same definition and preferred embodiments are also the same. L 31 and L 32 each independently represents a divalent organic group.

[0218] In addition, in the above formula (Ia-3), M 31a + , M 31b + , and M 32 + The organic cation represented by H + In compound PIa-3, A is replaced by 32 The acid dissociation constant a2 derived from the acidic site represented by H is A 31a The acid dissociation constants a1-3 and A2 derived from the acidic site represented by H 31b It is larger than the acid dissociation constant a1-4 derived from the acidic site represented by H. The acid dissociation constant a1-3 and the acid dissociation constant a1-4 correspond to the above-mentioned acid dissociation constant a1. In addition, A 31a - and A 32 - may be the same or different. 31a + , M 31b + , and M 32 + may be the same or different from each other. Also, M 31a + , M 31b + , M 32 + , A 31a - , A 32 - , L 31 , and L 32 At least one of them may have an acid-decomposable group as a substituent.

[0219] In formula (Ia-4), A 41a - , A 41b- , and A 42 - Each independently represents a monovalent anionic functional group. 41a - and A 41b - The definition of the monovalent anionic functional group represented by the formula (Ia-2) is as follows: 21a - and A 21b - Also, A 42 - The definition of the monovalent anionic functional group represented by the formula (Ia-3) is as follows: 32 - The same definition and preferred embodiments are also the same. M 41a + , M 41b + , and M 42 + each independently represents an organic cation. L 41 represents a trivalent organic group.

[0220] In addition, in the above formula (Ia-4), M 41a + , M 41b + , and M 42 + The organic cation represented by H + In compound PIa-4, A is replaced by 42 The acid dissociation constant a2 derived from the acidic site represented by H is A 41a The acid dissociation constants a1-5 and A2 derived from the acidic site represented by H 41b It is larger than the acid dissociation constant a1-6 derived from the acidic site represented by H. The acid dissociation constant a1-5 and the acid dissociation constant a1-6 correspond to the above-mentioned acid dissociation constant a1. In addition, A 41a - , A 41b - , and A 42 - may be the same or different. 41a + , M41b + , and M 42 + may be the same or different from each other. Also, M 41a + , M 41b + , M 42 + , A 41a - , A 41b - , A 42 - , and L 41 At least one of them may have an acid-decomposable group as a substituent.

[0221] L in formula (Ia-2) 21 and L 22 and L in formula (Ia-3). 31 and L 32 The divalent organic group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -NR-, -O-, -S-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), a divalent aliphatic heterocyclic group (preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring), a divalent aromatic heterocyclic group (preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring), a divalent aromatic hydrocarbon ring group (preferably a 6- to 10-membered ring, and even more preferably a 6-membered ring), and a divalent organic group formed by combining a plurality of these groups. The above R may be a hydrogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably, for example, an alkyl group (preferably having 1 to 6 carbon atoms). The alkylene group, the cycloalkylene group, the alkenylene group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon ring group may have a substituent, such as a halogen atom (preferably a fluorine atom).

[0222] L in formula (Ia-2) 21 and L 22 and L in formula (Ia-3). 31 and L 32 The divalent organic group represented by the formula (L2) is also preferably, for example, a divalent organic group represented by the following formula (L2).

[0223] [ka]

[0224] In formula (L2), q represents an integer of 1 to 3. * represents a bonding position. Each Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. In addition, the alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF3. In particular, it is further preferable that both Xf are fluorine atoms.

[0225] L A represents a single bond or a divalent linking group. L A The divalent linking group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -O-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), a divalent aromatic hydrocarbon ring group (preferably a 6- to 10-membered ring, more preferably a 6-membered ring), and a divalent linking group formed by combining a plurality of these. The alkylene group, the cycloalkylene group, and the divalent aromatic hydrocarbon ring group may have a substituent, for example, a halogen atom (preferably a fluorine atom).

[0226] Examples of the divalent organic group represented by formula (L2) include *-CF2-*, *-CF2-CF2-*, *-CF2-CF2-CF2-*, *-Ph-O-SO2-CF2-*, *-Ph-O-SO2-CF2-CF2-*, and *-Ph-O-SO2-CF2-CF2-CF2-*, *-Ph-OCO-CF2-*, etc. Ph is a phenylene group which may have a substituent, and is preferably a 1,4-phenylene group. The substituent is not particularly limited, but is preferably an alkyl group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), an alkoxy group (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or an alkoxycarbonyl group (e.g., preferably having 2 to 10 carbon atoms, more preferably having 2 to 6 carbon atoms). L in formula (Ia-2) 21 and L 22 When represents a divalent organic group represented by formula (L2), L in formula (L2) A The bond (*) on the side of the A 21a - and A 21b - It is preferred to combine with In addition, L in formula (Ia-3) 31 and L 32 When represents a divalent organic group represented by formula (L2), L in formula (L2) A The bond (*) on the side of the A 31a - and A 32 - It is preferred to combine with

[0227] L in formula (Ia-4) 41 The trivalent organic group represented by the formula (L3) is not particularly limited, and examples thereof include trivalent organic groups represented by the formula (L3) below.

[0228] [ka]

[0229] In formula (L3), L B represents a trivalent hydrocarbon ring group or a trivalent heterocyclic group. * represents the bonding position.

[0230] The hydrocarbon ring group may be an aromatic hydrocarbon ring group or an aliphatic hydrocarbon ring group. The number of carbon atoms contained in the hydrocarbon ring group is preferably 6 to 18, more preferably 6 to 14. The heterocyclic group may be an aromatic heterocyclic group or an aliphatic heterocyclic group. The heterocycle is preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring. L B Among them, a trivalent hydrocarbon ring group is preferable, and a benzene ring group or an adamantane ring group is more preferable. The benzene ring group or the adamantane ring group may have a substituent. The substituent is not particularly limited, and examples thereof include a halogen atom (preferably a fluorine atom).

[0231] In addition, in formula (L3), L B1 ~L B3 Each of L independently represents a single bond or a divalent linking group. B1 ~L B3The divalent linking group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -NR-, -O-, -S-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), a divalent aliphatic heterocyclic group (preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring), a divalent aromatic heterocyclic group (preferably a 5- to 10-membered ring having at least one N atom, O atom, S atom, or Se atom in the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring), a divalent aromatic hydrocarbon ring group (preferably a 6- to 10-membered ring, and even more preferably a 6-membered ring), and a divalent linking group formed by combining a plurality of these groups. The above R may be a hydrogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably, for example, an alkyl group (preferably having 1 to 6 carbon atoms). The alkylene group, the cycloalkylene group, the alkenylene group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon ring group may have a substituent, such as a halogen atom (preferably a fluorine atom). L B1 ~L B3 Of the above, the divalent linking group represented by the formula (I) is preferably -CO-, -NR-, -O-, -S-, -SO-, -SO2-, an alkylene group which may have a substituent, or a divalent linking group formed by combining a plurality of these.

[0232] L B1 ~L B3 Of the divalent linking groups represented by formula (L3-1), a divalent linking group represented by formula (L3-2) is more preferable.

[0233] [ka]

[0234] In formula (L3-1), L B11represents a single bond or a divalent linking group. L B11 The divalent linking group represented by the formula (I) is not particularly limited, and examples thereof include -CO-, -O-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched) that may have a substituent, and a divalent linking group that is a combination of a plurality of these. The substituent is not particularly limited, and examples thereof include a halogen atom. r represents an integer of 1 to 3. Xf has the same meaning as Xf in the above formula (L2), and the preferred embodiments are also the same. * indicates the bond position.

[0235] L B1 ~L B3 Examples of the divalent linking group represented by the formula include *-O-*, *-O-SO2-CF2-*, *-O-SO2-CF2-CF2-*, *-O-SO2-CF2-CF2-CF2-*, and *-COO-CH2-CH2-*. L in formula (Ia-4) 41 contains a divalent organic group represented by formula (L3-1), and the divalent organic group represented by formula (L3-1) and A 42 - When the bond is bonded to the carbon atom, the bond (*) on the carbon atom side shown in formula (L3-1) is A in formula (Ia-4). 42 - It is preferred to combine with

[0236] Next, the compound represented by formula (Ia-5) will be described.

[0237] [ka]

[0238] In formula (Ia-5), A 51a - , A 51b - , and A 51c - Each independently represents a monovalent anionic functional group. 51a- , A 51b - , and A 51c - The monovalent anionic functional group represented by the formula (I) is the above-mentioned anionic moiety A1 - A is intended to include a monovalent radical comprising 51a - , A 51b - , and A 51c - The monovalent anionic functional group represented by the formula (AX-1) to (AX-3) is not particularly limited, and examples thereof include monovalent anionic functional groups selected from the group consisting of the above-mentioned formulas (AX-1) to (AX-3). A 52a - and A 52b - represents a divalent anionic functional group. 52a - and A 52b - The divalent anionic functional group represented by the above-mentioned anionic moiety A2 - A divalent radical containing 22 - Examples of the divalent anionic functional group represented by the formula (BX-8) to (BX-11) include divalent anionic functional groups selected from the group consisting of the above-mentioned formulas (BX-8) to (BX-11).

[0239] M 51a + , M 51b + , M 51c + , M 52a + , and M 52b + Each independently represents an organic cation. 51a + , M 51b + , M 51c + , M 52a + , and M 52b + As the organic cation represented by the formula: + The same definition and preferred embodiments are also the same. L 51 and L 53 Each of L independently represents a divalent organic group. 51 and L 53 The divalent organic group represented by the formula (Ia-2) is 21 and L 22 The same definition and preferred embodiments are also the same. L 52 represents a trivalent organic group. 52 The trivalent organic group represented by the formula (Ia-4) is 41 The same definition and preferred embodiments are also the same.

[0240] In addition, in the above formula (Ia-5), M 51a + , M 51b + , M 51c + , M 52a + , and M 52b + The organic cation represented by H + In compound PIa-5, A is replaced by 52a The acid dissociation constants a2-1 and A2-1 derived from the acidic site represented by H 52b The acid dissociation constant a2-2 derived from the acidic site represented by H is A 51a Acid dissociation constant a1-1, A 51b The acid dissociation constants a1-2 and A 51c It is larger than the acid dissociation constant a1-3 derived from the acidic site represented by H. The acid dissociation constants a1-1 to a1-3 correspond to the above-mentioned acid dissociation constant a1, and the acid dissociation constants a2-1 and a2-2 correspond to the above-mentioned acid dissociation constant a2. In addition, A 51a - , A 51b - , and A 51c - may be the same or different. 52a - and A 52b - may be the same or different. 51a+ , M 51b + , M 51c + , M 52a + , and M 52b + may be the same or different from each other. Also, M 51b + , M 51c + , M 52a + , M 52b + , A 51a - , A 51b - , A 51c - , L 51 , L 52 , and L 53 At least one of them may have an acid-decomposable group as a substituent.

[0241] (Compound (II)) Compound (II) is a compound having two or more of the above structural moieties X and one or more of the following structural moieties Z, and is a compound that generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z when irradiated with actinic rays or radiation. Structural site Z: A non-ionic site capable of neutralizing an acid

[0242] In compound (II), the definition of the structural moiety X and A1 - and M1 + The definition of the structural moiety X in the compound (I) and A1 - and M1 + The definition and preferred embodiments are also the same as those of the above.

[0243] In the compound (II), the cationic moiety M1 in the structural moiety X + H + In the compound PII, the cationic moiety M1 in the structural moiety X is replaced by + H +The preferred range of the acid dissociation constant a1 derived from the acidic site represented by HA1 in which the acid dissociation constant a1 is substituted with HA1 is the same as the acid dissociation constant a1 in the above compound PI. In addition, when compound (II) is, for example, a compound that generates an acid having two of the first acidic sites derived from the structural site X and the structural site Z, compound PII corresponds to a "compound having two HA1s." When the acid dissociation constant of this compound PII is calculated, it is considered that compound PII has "one A1 - and one HA1" and the acid dissociation constant when "a compound having one A1 - and one HA1" is a "compound with two A1 - The acid dissociation constant at which the compound becomes "a compound having the formula (I)" corresponds to the acid dissociation constant a1.

[0244] The acid dissociation constant a1 can be determined by the above-mentioned method for measuring an acid dissociation constant. The above compound PII corresponds to an acid generated when compound (II) is irradiated with actinic rays or radiation. The two or more structural moieties X may be the same or different. - , and two or more of the above M1 + may be the same or different.

[0245] The nonionic site capable of neutralizing an acid in the structural site Z is not particularly limited, and is preferably, for example, a site containing a functional group having an electron or a group capable of electrostatically interacting with a proton. Examples of functional groups having a group or electrons capable of electrostatically interacting with a proton include functional groups having a macrocyclic structure such as cyclic polyether, or functional groups having a nitrogen atom having an unshared electron pair that does not contribute to π conjugation. The nitrogen atom having an unshared electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula:

[0246] [ka]

[0247] Examples of the partial structure of the functional group having a group or electron capable of electrostatically interacting with a proton include a crown ether structure, an azacrown ether structure, a primary to tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure. Among these, a primary to tertiary amine structure is preferable.

[0248] Compound (II) is not particularly limited, and examples thereof include compounds represented by the following formula (IIa-1) and formula (IIa-2).

[0249] [ka]

[0250] In the above formula (IIa-1), A 61a - and A 61b - Each of A in the above formula (Ia-1) 11 - The same definition and preferred embodiments are also the same. 61a + and M 61b + Each of them represents M in the above formula (Ia-1). 11 + The same definition and preferred embodiments are also the same. In the above formula (IIa-1), L 61 and L 62 Each of these has the same definition as L1 in the above formula (Ia-1), and the preferred embodiments are also the same.

[0251] In formula (IIa-1), R 2X R represents a monovalent organic group. 2X The monovalent organic group represented by the formula (I) is not particularly limited, and examples thereof include an alkyl group (preferably having 1 to 10 carbon atoms, which may be linear or branched), a cycloalkyl group (preferably having 3 to 15 carbon atoms), or an alkenyl group (preferably having 2 to 6 carbon atoms), in which -CH2- may be substituted with one or a combination of two or more selected from the group consisting of -CO-, -NH-, -O-, -S-, -SO-, and -SO2-. The alkylene group, the cycloalkylene group, and the alkenylene group may have a substituent. The substituent is not particularly limited, but examples thereof include a halogen atom (preferably a fluorine atom).

[0252] In addition, in the above formula (IIa-1), M 61a + and M 61b + The organic cation represented by H + In the compound PIIa-1, A is replaced by 61a The acid dissociation constants a1-7 and A 61b The acid dissociation constant a1-8 derived from the acidic site represented by H corresponds to the above-mentioned acid dissociation constant a1. In the compound (IIa-1), the cationic moiety M in the structural moiety X 61a + and M 61b + H + Compound PIIa-1, which is substituted with HA 61a -L 61 -N(R 2X )-L 62 -A 61b The compound PIIa-1 corresponds to H. In addition, the compound PIIa-1 and the acid generated from the compound represented by formula (IIa-1) upon irradiation with actinic rays or radiation are the same. Also, M 61a + , M 61b + , A 61a - , A 61b - , L 61 , L 62 , and R 2X At least one of them may have an acid-decomposable group as a substituent.

[0253] In the above formula (IIa-2), A 71a - , A 71b - , and A 71c -Each of A in the above formula (Ia-1) 11 - The same definition and preferred embodiments are also the same. 71a + , M 71b + , M 71c + Each of them represents M in the above formula (Ia-1). 11 + The same definition and preferred embodiments are also the same. In the above formula (IIa-2), L 71 , L 72 , and L 73 Each of these has the same definition as L1 in the above formula (Ia-1), and the preferred embodiments are also the same.

[0254] In addition, in the above formula (IIa-2), M 71a + , M 71b + , M 71c + The organic cation represented by H + In the compound PIIa-2, A is replaced by 71a The acid dissociation constants a1-9, A, derived from the acidic sites represented by H 71b The acid dissociation constants a1-10 and A 71c The acid dissociation constant a1-11 derived from the acidic site represented by H corresponds to the above-mentioned acid dissociation constant a1. In the compound (IIa-1), the cationic moiety M in the structural moiety X 71a + , M 71b + , M 71c + H + Compound PIIa-2, which is substituted with HA 71a -L 71 -N(L 73 -A 71c H)-L 72 -A 71b The compound PIIa-2 corresponds to H. In addition, the compound PIIa-2 and the acid generated from the compound represented by formula (IIa-2) upon irradiation with actinic rays or radiation are the same. Also, M 71a+ , M 71b + , M 71c + , A 71a - , A 71b - , A 71c - , L 71 , L 72 , and L 73 At least one of them may have an acid-decomposable group as a substituent.

[0255] Examples of the organic cation and other moieties that the specific photoacid generator may have are given below. The organic cation is, for example, M in the compounds represented by formulae (Ia-1) to (Ia-5). 11 + , M 12 + , M 21a + , M 21b + , M 22 + , M 31a + , M 31b + , M 32 + , M 41a + , M 41b + , M 42 + M 51a + , M 51b + , M 51c + , M 52a + , or M 52b + It can be used as. The other moiety is, for example, M in the compounds represented by formulae (Ia-1) to (Ia-5). 11 + , M 12 + , M 21a + , M 21b + , M22 + , M 31a + , M 31b + , M 32 + , M 41a + , M 41b + , M 42 + M 51a + , M 51b + , M 51c + , M 52a + , and M 52b + It can be used as other parts. The organic cations shown below and other moieties can be appropriately combined and used as specific photoacid generators.

[0256] First, examples of organic cations that the specific photoacid generator may have will be given.

[0257] [ka]

[0258] [ka]

[0259] [ka]

[0260] Next, examples of moieties other than the organic cation that the specific photoacid generator may have will be given.

[0261] [ka]

[0262] [ka]

[0263] The molecular weight of the specific photoacid generator is preferably from 100 to 10,000, more preferably from 100 to 2,500, and even more preferably from 100 to 1,500.

[0264] When the resist composition contains a specific photoacid generator, its content (the total content of compounds (I) and (II)) is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total solid content of the resist composition. The upper limit is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. The specific photoacid generator may be used alone or in combination of two or more. When two or more types are used, the total content is preferably within the above-mentioned suitable content range.

[0265] (Compound (III)) The resist composition may contain the following compound (III) as the photoacid generator (B). Compound (III) is a compound having two or more structural moieties X shown below, and generates two acidic moieties derived from the structural moieties X shown below when irradiated with actinic rays or radiation. Structural part X: Anion part A1 - and cationic moiety M1 + and a structural portion that forms an acidic site represented by HA1 upon irradiation with actinic rays or radiation.

[0266] The two or more structural moieties X contained in the compound (III) may be the same or different. - , and two or more of the above M1 + may be the same or different.

[0267] In compound (III), the definition of the structural moiety X and A1 - and M1 + The definition of the structural moiety X in the compound (I) and A1 - and M1 +The definition and preferred embodiments are also the same as those of the above.

[0268] The photoacid generator is "M + X - It is preferable that the compound is represented by M + represents an organic cation. The organic cation is preferably a cation represented by the above formula (ZaI) (cation (ZaI)) or a cation represented by the above formula (ZaII) (cation (ZaII)).

[0269] <Acid diffusion control agent (C)> The resist composition may contain an acid diffusion controller (C). The acid diffusion controller (C) traps the acid generated from the photoacid generator (B) etc. upon exposure and acts as a quencher to suppress the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid. Examples of the acid diffusion controller (C) that can be used include a basic compound (CA), a basic compound (CB) whose basicity is reduced or eliminated by irradiation with radiation, an onium salt (CC) that is a relatively weak acid compared to the photoacid generator (B), a low molecular weight compound (CD) that has a nitrogen atom and a group that is released by the action of an acid, and an onium salt compound (CE) that has a nitrogen atom in the cation moiety. In the resist composition, a known acid diffusion control agent can be appropriately used.For example, the known compounds disclosed in paragraphs

[0627] to

[0664] of US Patent Application Publication No. 2016 / 0070167, paragraphs

[0095] to

[0187] of US Patent Application Publication No. 2015 / 0004544, paragraphs

[0403] to

[0423] of US Patent Application Publication No. 2016 / 0237190, and paragraphs

[0259] to

[0328] of US Patent Application Publication No. 2016 / 0274458 can be suitably used as the acid diffusion control agent (C).

[0270] Examples of the basic compound (CA) include the repeating units described in paragraphs 0188 to 0208 of JP2019-045864A.

[0271] In the resist composition, an onium salt (CC) that is a relatively weak acid compared to the photoacid generator (B) can be used as the acid diffusion controller (C). When a photoacid generator (B) is used in combination with an onium salt that generates an acid that is weaker than the acid generated by the photoacid generator (B), when the acid generated by the photoacid generator (B) collides with an onium salt having an unreacted weak acid anion upon irradiation with actinic rays or radiation, the weak acid is released by salt exchange to generate an onium salt having a strong acid anion. In this process, the strong acid is exchanged for a weak acid with a lower catalytic activity, and the acid appears to be deactivated, thereby controlling acid diffusion.

[0272] Examples of onium salts that are relatively weak acids compared to the photoacid generator (B) include the onium salts described in paragraphs 0226 to 0233 of JP2019-070676A.

[0273] When the resist composition contains an acid diffusion controller (C), the content of the acid diffusion controller (C) (the total content when multiple types are present) is preferably 0.1 to 10.0 mass %, and more preferably 0.1 to 5.0 mass %, based on the total solid content of the resist composition. In the resist composition, the acid diffusion controller (C) may be used alone or in combination of two or more kinds.

[0274] <Hydrophobic resin (D)> The resist composition may contain a hydrophobic resin (D) that is different from the above resin (A). The hydrophobic resin (D) is preferably designed so as to be unevenly distributed on the surface of the resist film. However, unlike a surfactant, it does not necessarily have to have a hydrophilic group in the molecule, and does not necessarily have to contribute to uniformly mixing the polar and non-polar substances. The effects of adding the hydrophobic resin (D) include control of the static and dynamic contact angles of water on the resist film surface, and suppression of outgassing.

[0275] From the viewpoint of uneven distribution on the membrane surface layer, the hydrophobic resin (D) preferably has one or more of "fluorine atoms", "silicon atoms", and "CH3 partial structures contained in the side chain portion of the resin", and more preferably has two or more of them. In addition, the hydrophobic resin (D) preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on the side chain.

[0276] When the hydrophobic resin (D) contains a fluorine atom and / or a silicon atom, the fluorine atom and / or the silicon atom in the hydrophobic resin may be contained in the main chain or in the side chain of the resin.

[0277] When the hydrophobic resin (D) has a fluorine atom, the partial structure having a fluorine atom is preferably an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom. The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably having 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have a substituent other than a fluorine atom. The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have a substituent other than a fluorine atom. Examples of aryl groups having a fluorine atom include aryl groups such as a phenyl group and a naphthyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the aryl group may further have a substituent other than a fluorine atom. Examples of the repeating unit having a fluorine atom or a silicon atom include those exemplified in paragraph 0519 of US Patent Application Publication No. 2012 / 0251948.

[0278] As described above, the hydrophobic resin (D) also preferably has a CH3 partial structure in the side chain portion. Here, the CH3 partial structure possessed by the side chain portion in the hydrophobic resin includes a CH3 partial structure having an ethyl group, a propyl group, or the like. On the other hand, a methyl group directly bonded to the main chain of the hydrophobic resin (D) (e.g., an α-methyl group of a repeating unit having a methacrylic acid structure) is not included in the CH3 partial structure in the present invention because it contributes little to the surface uneven distribution of the hydrophobic resin (D) due to the influence of the main chain.

[0279] For the hydrophobic resin (D), the disclosure of paragraphs 0348 to 0415 of JP2014-010245A can be referred to, the contents of which are incorporated herein by reference.

[0280] As the hydrophobic resin (D), the resins described in JP-A-2011-248019, JP-A-2010-175859, and JP-A-2012-032544 can also be preferably used.

[0281] When the resist composition contains a hydrophobic resin (D), the content of the hydrophobic resin (D) is preferably from 0.01 to 20 mass %, and more preferably from 0.1 to 15 mass %, based on the total solid content of the resist composition.

[0282] <Surfactant (E)> The resist composition may contain a surfactant (E). By containing the surfactant (E), it is possible to form a pattern with excellent adhesion and fewer development defects. As the surfactant (E), a fluorine-based and / or silicon-based surfactant is preferred. Examples of fluorine-based and / or silicon-based surfactants include those described in paragraph 0276 of the specification of U.S. Patent Application Publication No. 2008 / 0248425. Other examples include EFTOP EF301 or EF303 (manufactured by Shin-Akita Chemical Industry Co., Ltd.); Fluorad FC430, 431 or 4430 (manufactured by Sumitomo 3M Limited); Megafac F171, F173, F176, F189, F113, F110, F177, F120 or R08 (manufactured by DIC Corporation); Surflon S-382, SC101, 102, 103, 104, 105 or 106 (manufactured by Asahi Glass Co., Ltd.); Troysol S-366 (manufactured by Troy Chemical Co., Ltd.); GF-300 or GF-150 (manufactured by Toagosei Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105 or 106 (manufactured by Asahi Glass Co., Ltd.), Troysol S-366 (manufactured by Troy Chemical Co., Ltd.), GF-300 or GF-150 (manufactured by Toagosei Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105 or 106 (manufactured by Asahi Glass ...66 (manufact Flon S-393 (manufactured by Seimi Chemical Co., Ltd.); F-top EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802 or EF601 (manufactured by JEMCO Co., Ltd.); PF636, PF656, PF6320 or PF6520 (manufactured by OMNOVA Co., Ltd.); KH-20 (manufactured by Asahi Kasei Co., Ltd.); FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D or 222D (manufactured by Neos Co., Ltd.) may also be used. In addition, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

[0283] In addition to the above-mentioned known surfactants, the surfactant (E) may be synthesized using a fluoroaliphatic compound produced by telomerization method (also called telomer method) or oligomerization method (also called oligomer method).Specifically, a polymer having a fluoroaliphatic group derived from the fluoroaliphatic compound may be used as the surfactant (E).The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-090991, for example. The polymer having a fluoroaliphatic group is preferably a copolymer of a monomer having a fluoroaliphatic group and a (poly(oxyalkylene)) acrylate and / or a (poly(oxyalkylene)) methacrylate, and may be irregularly distributed or block copolymerized. The poly(oxyalkylene) group may be a poly(oxyethylene) group, a poly(oxypropylene) group, or a poly(oxybutylene) group, and may also be a unit having alkylenes of different chain lengths within the same chain length, such as poly(block linkage of oxyethylene, oxypropylene, and oxyethylene) or poly(block linkage of oxyethylene and oxypropylene). Furthermore, the copolymer of a monomer having a fluoroaliphatic group and a (poly(oxyalkylene)) acrylate (or methacrylate) may be not only a binary copolymer, but also a ternary or higher copolymer in which two or more different monomers having a fluoroaliphatic group and two or more different (poly(oxyalkylene)) acrylates (or methacrylates) are simultaneously copolymerized. For example, commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (manufactured by DIC Corporation), and C6F 13 and copolymers of an acrylate (or methacrylate) having a C3F7 group, a (poly(oxyethylene)) acrylate (or methacrylate) and a (poly(oxypropylene)) acrylate (or methacrylate). In addition, surfactants other than the fluorine-based and / or silicone-based surfactants described in paragraph

[0280] of the specification of US Patent Application Publication No. 2008 / 0248425 may be used.

[0284] These surfactants (E) may be used alone or in combination of two or more.

[0285] The content of the surfactant (E) is preferably from 0.0001 to 2 mass %, and more preferably from 0.0005 to 1 mass %, based on the total solid content of the resist composition.

[0286] <Solvent (F)> The resist composition may contain a solvent (F). When the resist composition is an EUV resist composition, the solvent (F) preferably contains at least one selected from the group consisting of (M1) propylene glycol monoalkyl ether carboxylate and (M2) propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. In this case, the solvent may further contain components other than the components (M1) and (M2). A solvent containing component (M1) or (M2) is preferably used in combination with the above-mentioned resin (A), because this improves the coatability of the resist composition and enables the formation of a pattern with fewer development defects.

[0287] Furthermore, when the resist composition is a resist composition for use with ArF, examples of the solvent (F) include organic solvents such as alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds which may contain a ring (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates.

[0288] The content of the solvent (F) in the resist composition is preferably determined so that the solids concentration is 0.5 to 40 mass %. In particular, the solid content is preferably 10% by mass or more in terms of obtaining superior effects of the present invention.

[0289] <Other additives> The resist composition may further contain a crosslinker, an alkali-soluble resin, a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that enhances solubility in a developer.

[0290] The moisture content in the resist composition is not particularly limited, but is preferably 0.10% by mass or less. There is no particular lower limit to the moisture content, but it is often 0.01% by mass or more. The water content in the resist composition can be measured using a Karl Fischer water content analyzer.

[0291] The resist composition can also be suitably used as an EUV light photosensitive composition. EUV light has a wavelength of 13.5 nm, which is shorter than ArF light (wavelength 193 nm) and the like, and therefore the number of incident photons is smaller when exposed at the same sensitivity. Therefore, the effect of "photon shot noise," which is the stochastic variation in the number of photons, is large, leading to deterioration of LER and bridge defects. One way to reduce photon shot noise is to increase the exposure dose to increase the number of incident photons, but this is a trade-off with the demand for higher sensitivity.

[0292] When the value A calculated by the following formula (1) is high, the resist film formed from the resist composition has high absorption efficiency of EUV light and electron beams, which is effective in reducing photon shot noise. The value A represents the absorption efficiency of EUV light and electron beams by mass of the resist film. Formula (1): A=([H]×0.04+[C]×1.0+[N]×2.1+[O]×3.6+[F]×5.6+[S]×1.5+[I]×39.5) / ([H]×1+[C]×12+[N]×14+[O]×16+[F]×19+[S]×32+[I]×127) The value A is preferably 0.120 or more. Although there is no particular upper limit, if the value A is too large, the EUV light and electron beam transmittance of the resist film decreases, the optical image profile in the resist film deteriorates, and as a result, it becomes difficult to obtain a good pattern shape, so the value A is preferably 0.240 or less, and more preferably 0.220 or less.

[0293] In formula (1), [H] represents the molar ratio of hydrogen atoms derived from all solid contents to all atoms of all solid contents in the resist composition, [C] represents the molar ratio of carbon atoms derived from all solid contents to all atoms of all solid contents in the resist composition, [N] represents the molar ratio of nitrogen atoms derived from all solid contents to all atoms of all solid contents in the resist composition, [O] represents the molar ratio of oxygen atoms derived from all solid contents to all atoms of all solid contents in the resist composition, [F] represents the molar ratio of fluorine atoms derived from all solid contents to all atoms of all solid contents in the resist composition, [S] represents the molar ratio of sulfur atoms derived from all solid contents to all atoms of all solid contents in the resist composition, and [I] represents the molar ratio of iodine atoms derived from all solid contents to all atoms of all solid contents in the resist composition. For example, when the resist composition contains a resin (acid decomposable resin) whose polarity increases under the action of acid, a photoacid generator, an acid diffusion controller, and a solvent, the resin, the photoacid generator, and the acid diffusion controller correspond to the solid content. That is, the total atoms of the total solid content correspond to the total of all atoms derived from the resin, all atoms derived from the photoacid generator, and all atoms derived from the acid diffusion controller. For example, [H] represents the molar ratio of hydrogen atoms derived from the total solid content to all atoms of the total solid content, and based on the above example, [H] represents the molar ratio of the total of hydrogen atoms derived from the resin, the photoacid generator, and the acid diffusion controller to the total of all atoms derived from the resin, the photoacid generator, and the acid diffusion controller.

[0294] The A value can be calculated by calculating the ratio of the number of atoms contained when the structure and content of the components of the total solid content in the resist composition are known. Even when the components are unknown, the ratio of the number of atoms contained in the resist composition can be calculated by an analytical method such as elemental analysis of the resist film obtained by evaporating the solvent component of the resist composition.

[0295] [Method for producing resist composition] There are no particular limitations on the method for producing the resist composition, and one example is a method in which the various components that make up the resist composition are added to a stirring tank equipped with a stirring means and mixed to produce the resist composition. The components of the resist composition added to the stirring tank are as already explained.

[0296] The procedure for adding the above components to the stirring tank is not particularly limited. For example, various components may be added through a material inlet of a mixing vessel. When adding various components, the components may be added sequentially or all at once. When adding one component, it may be added in multiple batches. When the components are added sequentially to the stirring tank, the order of addition is not particularly limited.

[0297] When components other than the solvent are added to the stirring tank, the components may be dissolved in the solvent and then added to the stirring tank as a solution. In this case, the solution may be filtered through a filter before being added to the stirring tank in order to remove insoluble matters in the solution. In addition, when the solvent is introduced into the stirring tank, the solvent may be filtered through a filter before being introduced into the stirring tank. The filter used in the above step may be the filter used in the step X described above.

[0298] In producing the resist composition, it is preferable to stir and mix the mixture of the components. There are no particular limitations on the method for stirring and mixing, and known stirring means such as a stirring blade may be used. The temperature of the mixture to be stirred and mixed is not particularly limited, but is preferably 15 to 32°C, more preferably 20 to 24°C. There are no particular limitations on the stirring and mixing time, but from the standpoint of the balance between the uniformity of the resulting resist composition and productivity, a stirring and mixing time of 1 to 48 hours is preferred.

[0299] The method for transferring the resist composition from the stirring tank to the piping is not particularly limited, and examples of the method include a transfer method that utilizes gravity, a method that applies pressure from the liquid surface side of the resist composition, a method that creates negative pressure on the piping side, and a combination of two or more of these methods. In the case of applying pressure from the liquid surface side of the resist composition, there are a method utilizing the flow pressure generated by the liquid transfer and a method applying pressure using a gas. The liquid flow pressure is preferably generated by, for example, a pump (such as a liquid delivery pump or a circulation pump). Examples of the pump include a rotary pump, a diaphragm pump, a metering pump, a chemical pump, a plunger pump, a bellows pump, a gear pump, a vacuum pump, an air pump, and a liquid pump, and other suitable commercially available pumps. There is no particular limitation on the location where the pump is disposed. The gas used for pressurization is preferably a gas that is inactive or non-reactive with the resist composition, and specific examples thereof include nitrogen and rare gases such as helium and argon. When pressurizing using a gas, it is preferable that the pressure on the pipe side is not reduced and is atmospheric pressure. The method of creating a negative pressure on the piping side is preferably to reduce the pressure by using a pump, and more preferably to reduce the pressure to a vacuum.

[0300] The produced resist composition may be subjected to a filtration treatment. The filtration treatment may be a method of filtering the resist composition through a filter. Using a production apparatus in which a filter is provided on a circulation pipe, circulation filtration may be performed by passing the produced resist composition through the filter multiple times.

[0301] The filter may be the filter used for filtration described in step X. The pressure difference (pressure difference between the upstream side and downstream side) applied to the filter is preferably 200 kPa or less, more preferably 100 kPa or less. In addition, when filtering with the filter, it is preferable that the change in the pressure difference during filtering is small. When filtering, the linear velocity is 3 to 150 L / (hr m 2), and 5 to 120 L / (hr m 2 ) is more preferable, and 10 to 100 L / (hr m 2 ) is more preferred.

[0302] The resist composition produced in the stirring tank may be stored in a predetermined container. Examples of the container include a bloom-treated glass container and a container that has been treated so that the liquid-contacting part is made of a fluororesin. When the resist composition is contained in a container, the space in the container (the area in the container not occupied by the resist composition) may be replaced with a predetermined gas. The gas is preferably a gas that is inactive or non-reactive with the resist composition, and examples of the gas include nitrogen and rare gases such as helium and argon. Before the resist composition is placed in the container, a degassing process may be carried out to remove dissolved gases from the resist composition. Examples of the degassing method include ultrasonic treatment and defoaming treatment.

[0303] <Quality inspection of resist composition> The produced resist composition is applied to a member such as a substrate using a resist coating apparatus that has been cleaned by this cleaning method, and is used to produce a resist film. In order to confirm the effect of the present cleaning method in suppressing the occurrence of defects in a resist film, it is preferable to carry out a quality inspection of the resist composition, which includes a resist film formation step in which a resist composition is applied onto a substrate using a resist coating apparatus cleaned by the present cleaning method to form a resist film, and a defect measurement step in which the number of defects in the formed resist film is measured using a defect inspection apparatus.

[0304] The cleaning method, resist coating apparatus, substrate for inspection, and resist composition used in the above quality inspection are as described above. The resist film forming step of coating the resist composition on the substrate to form a resist film is as described below as step A in the section [Formation of resist film and resist pattern]. The above defect measuring step can be carried out according to a known method for measuring defects in a resist film. There are no particular limitations on the size of defects present in the resist film to be measured, and for example, the number of defects having a size of 40 nm or more is measured. The number of defects present in the resist film can be measured using a defect inspection device (for example, a dark-field defect inspection device SP5 manufactured by KLA Tencor Corporation).

[0305] The more residues adhering to the liquid-contacting parts of the coating apparatus are removed by the cleaning method performed on the coating apparatus, the fewer the number of defects in the resist film measured by the quality inspection. Therefore, the quality inspection can confirm the residue removal performance of the cleaning method performed on the coating apparatus. The cleaning method according to the present invention has the effect of efficiently reducing the amount of residues derived from the resist composition adhering to the inside of the coating apparatus in a short period of time and further suppressing the occurrence of defects in the resist film.

[0306] As a method for producing a resist composition, it is preferable to produce a resist composition in which the number of defects in the resist film is reduced according to the results of the quality inspection after carrying out the above-mentioned quality inspection. That is, if the result of carrying out the above-mentioned quality inspection shows that the number of defects in the measured resist film is equal to or less than a predetermined reference value, it is preferable to produce a resist composition according to a production method that can obtain that result. This is because a resist composition with excellent quality can be produced. The above reference value can be set appropriately depending on conditions such as the configuration of the resist coating equipment, the formulation of the resist composition, and the precision required for the resist pattern to be formed.

[0307] [Formation of resist film and resist pattern] The resist composition is used, for example, for forming a resist film and a resist pattern. The method for forming a resist film using the resist composition is not particularly limited, and examples thereof include a method having a step of forming a resist film on a substrate using the resist composition.

[0308] There are no particular limitations on the procedure for forming a resist pattern using the resist composition, but it is preferable for the method to include the following steps. Step A: A step of applying a resist composition onto a substrate using the resist coating apparatus to form a resist film. Step B: A step of exposing the resist film to light Step C: A step of developing the exposed resist film using a developer to form a pattern. The procedures for each of the above steps will be described in detail below.

[0309] <Process A: Resist film formation process> Step A is a step of applying a resist composition onto a substrate using a resist coating apparatus to form a resist film. The resist coating apparatus and the resist composition are as already explained.

[0310] Before coating, the resist composition may be filtered as necessary, and is preferably filtered. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon. The above filter is preferably installed on the piping of the resist coating device.

[0311] There are no particular limitations on the substrate to which the resist composition is applied, so long as it is a substrate used in the manufacture of integrated circuit elements, and examples thereof include silicon wafers and silicon wafers coated with silicon dioxide. The resist composition is applied onto the surface of the substrate from the nozzle of the resist coating device. There are no particular limitations on the coating method, and coating means such as a spinner or a coater can be used, with spin coating using a spinner being preferred.

[0312] After coating the resist composition, the coating may be dried to form a resist film. If necessary, various undercoats (inorganic films, organic films, or anti-reflective films) may be formed under the resist film. The drying method includes a method of heating the substrate having the coating film (pre-baking: PB). Heating can be performed by a means provided in a normal exposure machine and / or a developing machine, and may also be performed using a hot plate or the like. The heating temperature is preferably from 80 to 150°C, and more preferably from 80 to 140°C. The heating time is preferably from 30 to 1000 seconds, and more preferably from 40 to 800 seconds.

[0313] There are no particular limitations on the thickness of the resist film, but in the case of a resist film for KrF exposure, the thickness is preferably from 0.2 to 12 μm, and more preferably from 0.3 to 5 μm. In the case of a resist film for ArF exposure or EUV exposure, the thickness is preferably from 30 to 700 nm, more preferably from 40 to 400 nm, and even more preferably from 40 to 200 nm. The thickness of the resist film can be adjusted by controlling conditions such as the formulation and viscosity of the resist composition, as well as the temperature of the resist composition to be applied and the rotation speed of the spin coater.

[0314] A top coat may be formed on the resist film using a top coat composition. It is preferable that the top coat composition does not mix with the resist film and can be applied uniformly onto the resist film. The thickness of the top coat is preferably from 10 to 200 nm, more preferably from 20 to 100 nm. The top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, the top coat can be formed based on the description in paragraphs 0072 to 0082 of JP2014-059543A.

[0315] <Process B: Exposure process> Step B is a step of exposing the resist film to light. The exposure method may be a method in which the formed resist film is irradiated with radiation through a predetermined mask. Examples of the radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and EB (Electron Beam), preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, and even more preferably 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), EUV (13 nm), X-rays, and EB.

[0316] After exposure, it is preferable to perform baking (post-exposure bake: PEB) before development. The heating temperature is preferably from 80 to 150°C, and more preferably from 80 to 140°C. The heating time is preferably from 10 to 1000 seconds, and more preferably from 10 to 180 seconds. Heating can be carried out by a means provided in a normal exposure machine and / or a developing machine, and may also be carried out using a hot plate or the like. This step is also referred to as post-exposure bake.

[0317] <Process C: Development process> Step C is a step of developing the exposed resist film with a developer to form a pattern.

[0318] Development methods include a method in which the substrate is immersed in a tank filled with developer for a certain period of time (dip method), a method in which the developer is piled up on the substrate surface by surface tension and left to stand for a certain period of time (paddle method), a method in which the developer is sprayed onto the substrate surface (spray method), and a method in which the developer is continuously dispensed by scanning a developer dispensing nozzle at a constant speed over a substrate rotating at a constant speed (dynamic dispense method). After the developing step, a step of stopping the development while replacing the solvent with another solvent may be carried out. The development time is not particularly limited as long as the resin in the unexposed area is sufficiently dissolved, and is preferably from 10 to 300 seconds, more preferably from 20 to 120 seconds. The temperature of the developer is preferably from 0 to 50°C, and more preferably from 15 to 35°C.

[0319] The developer may be an alkaline developer or an organic solvent developer. As the alkaline developer, it is preferable to use an alkaline aqueous solution containing an alkali. In particular, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt, typically tetramethylammonium hydroxide (TMAH). The alkaline developer may contain an appropriate amount of alcohol, surfactant, etc. The alkaline concentration of the alkaline developer is usually 0.1 to 20 mass %. The pH of the alkaline developer is usually 10.0 to 15.0.

[0320] The organic solvent developer is a developer that contains an organic solvent. Examples of the organic solvent used in the organic solvent developer include known organic solvents, such as ester-based solvents, ketone-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

[0321] <Other processes> The above pattern formation method preferably includes, after step C, a step of washing with a rinsing liquid. The rinse liquid used in the rinse step following the step of developing with a developer may be, for example, pure water, to which an appropriate amount of a surfactant may be added. A suitable amount of a surfactant may be added to the rinse solution.

[0322] Furthermore, the substrate may be etched using the formed pattern as a mask. That is, the substrate (or the underlayer film and the substrate) may be processed using the pattern formed in step C as a mask to form a pattern on the substrate. The method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, but a method of forming a pattern on the substrate by dry etching the substrate (or the underlayer film and the substrate) using the pattern formed in step C as a mask is preferred. The dry etching may be a single-stage etching or a multi-stage etching. When the etching is a multi-stage etching, each stage of the etching may be the same process or different processes. Any known method can be used for the etching, and various conditions, etc. are appropriately determined depending on the type or use of the substrate, etc. For example, etching can be performed according to the method described in "Chapter 4 Etching" of "Semiconductor Processing Textbook, Fourth Edition, Published in 2007, Publisher: SEMI Japan." Among them, oxygen plasma etching is preferable as the dry etching.

[0323] The various materials used in the present cleaning method and resist composition (e.g., solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppb or less, even more preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Mo, Zr, Pb, Ti, V, W, and Zn.

[0324] An example of a method for removing impurities such as metals from the various materials is filtration using a filter. The filter pore size is preferably 0.20 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 μm or less. The filter material is preferably a fluororesin such as polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA), a polyolefin resin such as polypropylene and polyethylene, or a polyamide resin such as nylon 6 and nylon 66. The filter may be washed in advance with an organic solvent. In the filter filtration step, a plurality of or a plurality of types of filters may be connected in series or parallel. When a plurality of types of filters are used, filters having different pore sizes and / or materials may be used in combination. In addition, various materials may be filtered a plurality of times, and the step of filtering a plurality of times may be a circulating filtration step. As the circulating filtration step, for example, a method as disclosed in JP-A-2002-062667 is preferable. As the filter, one with reduced elution such as that disclosed in JP2016-201426A is preferable. In addition to filtration, impurities may be removed using an adsorbent, or a combination of filtration and an adsorbent may be used. As the adsorbent, a known adsorbent may be used, for example, an inorganic adsorbent such as silica gel or zeolite, or an organic adsorbent such as activated carbon. As the metal adsorbent, for example, those disclosed in JP 2016-206500 A may be used. In addition, methods for reducing impurities such as metals contained in the various materials include selecting raw materials with low metal contents as raw materials constituting the various materials, filtering the raw materials constituting the various materials, or performing distillation under conditions that suppress contamination as much as possible by lining or coating the inside of the apparatus with fluororesin, etc. The preferred conditions for filtering the raw materials constituting the various materials are the same as those described above. In order to prevent the inclusion of impurities, the various materials described above are preferably stored in containers such as those described in U.S. Patent Application Publication No. 2015 / 0227049, Japanese Patent Application Publication No. 2015-123351, and Japanese Patent Application Publication No. 2017-013804. The various materials may be used after diluting with a solvent used in the resist composition.

[0325] [Electronic device manufacturing] The resist film and resist pattern formed using the resist composition may be used in the manufacture of electronic devices. Preferred embodiments of the electronic device include those installed in electric and electronic equipment (home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment, etc.). EXAMPLES

[0326] The present invention will be described in more detail below with reference to the following examples. The materials, amounts, ratios, processing contents, processing 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 interpreted as being limited by the following examples.

[0327] [Raw materials] <Resin (A)> In the examples and comparative examples, resins A-1 and A-2 were used as the resin (A). Both resins A-1 and A-2 were synthesized based on known techniques. The structures of resins A-1 and A-2 are shown below, along with the composition ratio (molar ratio), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit in resin A-2. The composition ratio (molar ratio) of each repeating unit in resin A-1 was "60 / 30 / 10" from the left, and the weight average molecular weight (Mw) of resin A-1 was 23,000, and the dispersity (Mw / Mn) was 1.51. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of resins A-1 and A-2, and resin D-1 described later are polystyrene equivalent values ​​measured by the above-mentioned GPC method (carrier: tetrahydrofuran (THF)). The composition ratio (mol %) of the repeating units in each resin is as follows: 13 Measurements were performed using C-NMR (Nuclear Magnetic Resonance).

[0328] [ka]

[0329] <Photoacid generator (B)> The structures of compounds B-1 and B-2 used as the photoacid generator (B) in the examples and comparative examples are shown below.

[0330] [ka]

[0331] <Acid diffusion control agent (C)> In the examples and comparative examples, the following compounds C-1 and C-2 were used as acid diffusion controllers.

[0332] [ka]

[0333] C-2: Dicyclohexylmethylamine

[0334] <Hydrophobic resin (D)> In the examples and comparative examples, the following resin D-1 was used as the hydrophobic resin (D). Resin D-1 was synthesized based on a known technique. The structure of Resin D-1, the composition ratio (molar ratio) of each repeating unit, the weight average molecular weight (Mw), and the dispersity (Mw / Mn) are as follows:

[0335] [ka]

[0336] <Surfactant (E)> The surfactants used in the examples and comparative examples are shown below. E-1: Megafac F176 (DIC Corporation)

[0337] <Solvent (F)> The solvents used in the examples and comparative examples are shown below. PGMEA: Propylene glycol monomethyl ether acetate

[0338] [Preparation of resist composition] The following operations were carried out in a class 6 (class notation according to the international unified standard ISO 14644-1) clean room with a temperature of 22.0° C., humidity of 58%, and atmospheric pressure of 102.6 kPa, to produce a resist composition.

[0339] <Resist composition ArF-1> A resist composition ArF-1 was prepared by mixing the components shown below. ·Resin A-1 (acid decomposable resin (A)) 1,267g Compound B-1 (photoacid generator (B)) 101g Compound C-1 (acid diffusion control agent (C)) 22g Compound D-1 (hydrophobic resin (D)) 10g PGMEA (solvent (F)) 38,600g

[0340] The resist composition ArF-1 prepared by the above procedure was subjected to two different filtration treatments, as described below, to prepare two resist compositions, ArF-1A and ArF-1B.

[0341] (Resist composition ArF-1A) Resist composition ArF-1 (18,000 g) was filtered through a polyethylene filter having a pore size of 100 nm manufactured by Entegris to obtain resist composition ArF-1A.

[0342] (Resist composition ArF-1B) Resist composition ArF-1 (18,000 g) was filtered through a polyethylene filter having a pore size of 3 nm manufactured by Entegris to obtain resist composition ArF-1B.

[0343] <Resist composition KrF-1> Resist composition KrF-1 was prepared by mixing the components shown below. Resin A-2 (acid-decomposable resin (A)) 3,914g Compound B-2 (photoacid generator (B)) 80g Compound C-2 (acid diffusion control agent (C)) 4g Compound E-1 (Surfactant (E)) 2g PGMEA (solvent (F)) 36,000g

[0344] The resist composition KrF-1 prepared by the above procedure was subjected to two different filtration treatments as described below, thereby preparing two resist compositions, KrF-1A and KrF-1B.

[0345] (Resist composition KrF-1A) Resist composition KrF-1 (18,000 g) was filtered through a polyethylene filter having a pore size of 200 nm manufactured by Entegris to obtain resist composition KrF-1A.

[0346] (Resist composition KrF-1B) Resist composition KrF-1 (18,000 g) was filtered through a polyethylene filter having a pore size of 20 nm manufactured by Entegris to obtain resist composition KrF-1B.

[0347] [Examples 1 to 10 and Comparative Examples 1 to 8 (Cleaning of Resist Coating Equipment)] Table 6 shows the cleaning methods for the resist coating apparatus carried out in each of the examples and comparative examples. In the table, the "Solvent" columns for "Process 1" and "Process 2" indicate the solvent used to clean the resist coating equipment in each process. In the examples and comparative examples, the resist coating equipment was cleaned in the order of "Step 1" and then "Step 2". However, if a solvent is not listed in each column (if it is marked "-"), it means that the step was not performed. Also, in examples 1 to 5, in which two types of solvents are used as "Step 1", it means that the step of cleaning the resist coating equipment with the solvent listed on the left (Step 1-1) was performed, and then the step of cleaning the resist coating equipment with the solvent listed on the right (Step 1-2) was performed.

[0348] In the table, "PGMEA" represents propylene glycol monomethyl ether acetate, "PGME" represents propylene glycol monomethyl ether, and "mixed solvent A1" represents a mixed solvent of PGMEA and PGME (PGMEA / PGME=30 / 70 (mass ratio)). In the table, the "SP value" column indicates the SP value (unit: MPa) of the solvent listed in the column to the left. 1 / 2 ) is shown. In the examples and comparative examples, each solvent was filtered using a 3 nm polyethylene filter manufactured by Entegris before being used to clean a resist coating device. The filtration procedure was based on the method described in JP 2016-075920 A.

[0349] [Table 9]

[0350] 〔evaluation〕 For each of the cleaning methods of the examples and comparative examples, the cleaning ability of the resist coating device was evaluated by the following method.

[0351] <Examples A-1 to A-10, Comparative Examples A-1 to A-8> First, a gallon bottle filled with 1 gallon of the above resist composition ArF-1A as "pre-cleaned resist" was connected to the resist line of a coater of a resist coating device (Tokyo Electron Co., Ltd. "Clean Track ACT12") (hereinafter, also simply referred to as "coating device"). (Note that, when connecting, a dummy capsule was used without connecting a filter to the connecting pipe.) Next, a dummy dispense was performed in which the resist composition filled in the gallon bottle was discharged from the tip of the resist nozzle of the coater through the resist line. This allowed all of the resist composition to pass through the resist line of the coater.

[0352] Next, the resist line of the coating device was cleaned by the cleaning method shown in Table 7 below. In each process, 2 gallons of each solvent listed in the table above were prepared and used. In each process, first, a dummy dispense was performed in which 1 gallon of solvent was pumped from a gallon bottle to the tip of the resist nozzle to clean the resist line of the coating device. Next, a dummy dispense was performed in which the remaining 1 gallon of solvent was pumped by nitrogen pressure to clean the resist line of the coating device.

[0353] In the cleaning of the resist line, in the dummy dispense of the second gallon (liquid delivery by nitrogen pressure) in the last process of each cleaning method, the entire amount of solvent was not discharged, but some of the solvent was left and the dummy dispense was stopped. Next, the remaining solvent was discharged from the resist nozzle of the coating device at a flow rate of 1 mL / s for 10 seconds onto the surface of a 12-inch (300 mm) diameter silicon wafer. After that, the silicon wafer with the solvent coated on its surface was baked at 100°C for 60 seconds. Taking the cleaning method of Example 1 as an example, first, step 1-1 was performed to clean the resist line using 2 gallons of butyl acetate, then step 1-2 was performed to clean the resist line using 2 gallons of cyclohexanone, and finally step 2 was performed to clean the resist line using 2 gallons of γ-butyrolactone. In step 2 of Example 1, 1 gallon of γ-butyrolactone was pumped to perform a dummy dispense, and then most of the 1 gallon of γ-butyrolactone was pumped under nitrogen pressure to perform a dummy dispense, and then the remaining small amount of γ-butyrolactone was applied to the silicon wafer. Then, the silicon wafer coated with γ-butyrolactone was baked as described above.

[0354] For the silicon wafers obtained by the above procedure, a dark-field defect inspection device SP5 manufactured by KLA Tencor Corporation was used to measure the number of defects (defect count) having a size of 19 nm or more present on the surface of the silicon wafer. The number of defects on the surface of the silicon wafer used in the evaluation test was measured using the above inspection device before applying the solvent. In addition, in the measurement of the number of defects on the silicon wafer surface and the measurement of the number of defects on the resist film surface described later, the number of defects was measured on concentric circles of the silicon wafer with an area of ​​660 cm. 2 The area within the circle was used as the measurement area. Based on the number of defects increased by the application of the solvent, which was derived from the number of defects measured before and after the application of the solvent, the cleaning performance of each cleaning method of the examples and comparative examples was evaluated according to the following criteria. The evaluation results are shown in Table 7 as "Solvent Defect Evaluation".

[0355] (Evaluation criteria (solvent defect evaluation)) A: The increase in the number of defects on the silicon wafer surface is less than 200. B: The increase in the number of defects on the silicon wafer surface is 200 or more and less than 300. C: The increase in the number of defects on the silicon wafer surface is 300 or more and less than 400. D: The increase in the number of defects on the silicon wafer surface is 400 or more and less than 500. E: The number of defects on the silicon wafer surface increases by 500 or more.

[0356] Next, the resist line of the coating device that had been cleaned by the above method was connected to a gallon bottle filled with 1 gallon of the above resist composition ArF-1B as the "cleaned resist" (when connecting, no filter was connected to the connecting piping, and a dummy capsule was used). A dummy dispense was performed by discharging 0.5 gallons of the resist composition ArF-1B from the tip of the resist nozzle of the coater through the resist line. Next, the resist composition ArF-1B was discharged from the resist nozzle of the coating device at a flow rate of 1 mL / s for 3 seconds onto the surface of the silicon wafer coated with the solvent, and then baked at 100° C. for 60 seconds to form a resist film on the surface of the silicon wafer. At this time, the thickness of the formed resist film was adjusted to 100 nm.

[0357] For the silicon wafers obtained by the above procedure, the number of defects (defect count) having a size of 40 nm or more present on the surface of the resist film was measured using a dark-field defect inspection device SP5 manufactured by KLA Tencor Corporation. Based on the measurement results of the number of defects on the resist film surface, the cleaning performance of each cleaning method of the examples and comparative examples was evaluated according to the following criteria. The evaluation results are shown in Table 7 as "resist defect evaluation". In this evaluation of the number of defects on the resist film surface, since the pre-cleaning resist and the post-cleaning resist used in each example and each comparative example are the same, it is possible to perform a relative evaluation of the cleaning performance of the cleaning method of each example and each comparative example. In other words, the smaller the number of defects measured on the resist film surface, the better the cleaning performance of the cleaning method carried out is, compared to when the number of defects is large.

[0358] (Evaluation criteria (resist defect evaluation)) A: The number of defects on the resist film surface is less than 20. B: The number of defects on the resist film surface is 20 or more and less than 40. C: The number of defects on the resist film surface is 40 or more and less than 70. D: The number of defects on the resist film surface is 70 or more and less than 100. E: The number of defects on the resist film surface is 100 or more.

[0359] Table 7 below shows the resist line cleaning methods used in Examples A-1 to A-10 and Comparative Examples A-1 to A-8, the resist compositions used, and the evaluation results of solvent defects and resist defects.

[0360] [Table 10]

[0361] <Examples K-1 to K-10, Comparative Examples K-1 to K-8> The cleaning methods of the examples and comparative examples were evaluated according to the methods described in Examples A-1 to A-10 and Comparative Examples A-1 to A-8, except that the above resist composition KrF-1A and resist composition KrF-1B were used as the "pre-cleaned resist" and the "post-cleaned resist", respectively, the coating film formed using the post-cleaned resist was baked at 130°C for 60 seconds to form a resist film with a thickness of 400 nm, and the number of defects (defect count) having a size of 100 nm or more present on the surface of the resist film was measured. Table 8 below shows the resist line cleaning methods, resist compositions used, and the evaluation results of solvent defects and resist defects in Examples K-1 to K-10 and Comparative Examples K-1 to K-8.

[0362] [Table 11]

[0363] As shown in Tables 7 and 8, it was confirmed that the cleaning method of the present invention can obtain the desired effects.

[0364] In particular, from a comparison of Examples 6 to 10, the SP value of the solvent A used in step 1 was 18.5 to 21.5 MPa. 1 / 2 It has been confirmed that the effect of the present invention is more excellent when Furthermore, a comparison of Examples 1 to 8 confirmed that the effects of the present invention are more excellent when steps 1-1 and 1-2 are carried out in step 1 using solvents A each having a different SP value. Furthermore, a comparison of Examples 1 to 5 confirmed that the effects of the present invention were even more excellent when the SP value of the solvent A2 used in step 1-2 was higher than the SP value of the solvent A1 used in step 1-1.

Claims

1. A method for cleaning a resist coating apparatus, comprising the steps of: SP value: 16.0 to 21.5 MPa １／２ a step 1 of cleaning the resist coating apparatus using the solvent A; After step 1, the SP value is 21.5 MPa. １／２ Over 30.0MPa １／２ and a step 2 of cleaning the resist coating apparatus using a solvent B as follows: the resist coating apparatus is an apparatus having a function of transferring a resist composition and applying the resist composition to a surface of a substrate, The resist composition comprises a resin whose polarity increases under the action of an acid, a photoacid generator, and a solvent.

2. The SP value of the solvent A is 18.5 to 21.5 MPa. １／２ 2. The method for cleaning a resist coating apparatus according to claim 1,

3. 3. The method for cleaning a resist coating apparatus according to claim 1, wherein at least one of the solvent A and the solvent B contains at least one selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents.

4. The process 1 includes a process 1-1 of cleaning the resist coating apparatus using a solvent A1 contained in the solvent A; After the step 1-1, a step 1-2 is included in the solvent A and is for cleaning the resist coating apparatus using a solvent A2 having a different SP value from the solvent A1. The method for cleaning a resist coating apparatus according to any one of claims 1 to 3.

5. 5. The method for cleaning a resist coating apparatus according to claim 4, wherein the SP value of the solvent A2 is higher than the SP value of the solvent A1.

6. 6. The method for cleaning a resist coating apparatus according to claim 4, wherein the solvent A1 includes at least one selected from the group consisting of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents.

7. The method further comprises at least one step selected from the group consisting of a step X of filtering the solvent A used in the step 1 through a filter before the step 1, and a step Y of filtering the solvent B used in the step 2 through a filter before the step 2. The method for cleaning a resist coating apparatus according to any one of claims 1 to 6.

8. a step 4 of applying at least one of the solvents used in the steps 1 and 2 onto the substrate using the resist application device; After the step 4, a step 5 of measuring the number of defects on the substrate using a defect inspection device, If the number of defects measured in step 5 exceeds the reference value, at least one step selected from the group consisting of step 1 and step 2 is carried out again. The method for cleaning a resist coating apparatus according to any one of claims 1 to 7.

9. a resist film forming step of applying a resist composition onto a substrate using a resist coating apparatus cleaned by the cleaning method according to any one of claims 1 to 8 to form a resist film; and a defect measuring step of measuring the number of defects in the resist film using a defect inspection device.

10. A method for producing a resist composition, comprising: carrying out a quality inspection of a resist composition in accordance with the quality inspection method according to claim 9; and producing a resist composition having a reduced number of defects in a resist film, depending on results obtained by the quality inspection.

11. A method for producing an electronic device, comprising: forming a resist film on a substrate using the resist composition produced by the method according to claim 10; and producing an electronic device using the resist film.

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