Treatment liquid and pattern forming method

Abstract

To provide a treatment liquid which enables pattern formation excellent in resolution when being used in at least one of development and cleaning (rinse) to a resist film, and is less likely to cause charging when being brought into contact with a fluorine-based resin, and a pattern formation method relating to the treatment liquid.SOLUTION: A treatment liquid is a treatment liquid for resist film patterning which is used in at least one of development and cleaning after exposure to a resist film obtained by an actinic ray-sensitive or radiation-sensitive composition, and contains a fluorine-based solvent having 3 to 5 carbon atoms, and an organic solvent other than the fluorine-based solvent having 3 to 5 carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a processing liquid for resist film patterning and a pattern forming method. More particularly, the present invention relates to a processing liquid and a pattern forming method used in semiconductor manufacturing processes such as ICs (Integrated Circuits), manufacturing circuit boards such as liquid crystal and thermal heads, and other photofabrication lithography processes. [Background technology]

[0002] Conventionally, in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrated Circuits), microfabrication has been performed by lithography using a photoresist composition. In recent years, with the increasing integration density of integrated circuits, there has been a demand for the formation of ultrafine patterns in the submicron and quarter-micron ranges. Accordingly, there has been a trend toward shorter exposure wavelengths, from g-line to i-line and then to KrF excimer laser light. Furthermore, in addition to excimer laser light, lithography using electron beams, X-rays, or EUV light (Extreme Ultra Violet) is also currently being developed. In such lithography, a film (resist film) is formed from an actinic ray- or radiation-sensitive composition (also referred to as a resist composition), and then the resulting film is developed with a developer and the developed film is washed with a rinse solution. For example, Patent Document 1 discloses a developer or rinse containing a predetermined organic solvent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-257379 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the increasing integration density of integrated circuits, there has been a demand for the formation of fine patterns (high-resolution patterns) using resist compositions. In the formation of such fine patterns, the distance between patterns decreases as the pattern size decreases, which causes a large capillary force, making it difficult to form high-quality patterns. The present inventors have found that when the treatment liquid specifically disclosed in Patent Document 1 (a fluorine-based solvent having 6 to 10 carbon atoms) is used, the desired effect cannot be obtained.

[0005] Furthermore, the inner walls of pipes used in semiconductor facilities and equipment are sometimes coated with fluororesins, such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers. If static electricity is generated when processing liquids are passed through such pipes, pinholes may form, leading to problems such as leakage.

[0006] The present invention has been made in view of the above points, and an object of the present invention is to provide a treatment liquid that, when used for at least one of developing and cleaning (rinsing) a resist film, enables pattern formation with excellent resolution and is less likely to become charged when it comes into contact with a fluorine-based resin. Another object of the present invention is to provide a pattern forming method using the above-mentioned treatment liquid. [Means for solving the problem]

[0007] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by the following configuration, and have thus completed the present invention.

[0008] (1) A treatment solution for resist film patterning, which is used to perform at least one of post-exposure development and washing of a resist film obtained from an actinic ray- or radiation-sensitive composition, A treatment liquid containing a fluorine-containing solvent having 3 to 5 carbon atoms and an organic solvent other than the fluorine-containing solvent having 3 to 5 carbon atoms. (2) The treatment liquid according to (1), wherein the organic solvent contains a hydrocarbon that may have a heteroatom. (3) The processing liquid according to (1) or (2), wherein the processing liquid is a rinse liquid. (4) The treatment liquid according to any one of (1) to (3), wherein the number of fluorine atoms contained in the fluorine-based solvent is at least twice the number of carbon atoms contained in the fluorine-based solvent. (5) The treatment liquid according to any one of (1) to (4), wherein the content of the fluorine-containing solvent is 10 to 80 mass % based on the total mass of the treatment liquid. (6) The treatment liquid according to any one of (1) to (5), wherein the fluorine-containing solvent comprises at least one selected from the group consisting of 2H,3H-decafluoropentane and 1H-undecafluoropentane. (7) The treatment liquid according to any one of (1) to (6), wherein the organic solvent comprises at least one solvent selected from the group consisting of ester-based solvents, ether-based solvents, alcohol-based solvents, ketone-based solvents, and hydrocarbon-based solvents. (8) The organic solvent includes an acyclic ester solvent, the acyclic ester solvent has 5 or more carbon atoms, The treatment liquid according to any one of (1) to (7), wherein the absolute value of the difference between the boiling point of the acyclic ester solvent and the boiling point of the fluorine-containing solvent is 50° C. or more. (9) The treatment liquid according to (8), wherein the organic solvent comprises at least one selected from the group consisting of isopropyl propionate, sec-butyl acetate, isoamyl formate, butyl acetate, diethyl carbonate, butyl butyrate, amyl butyrate, isobutyl butyrate, isobutyl acetate, tert-butyl acetate, isoamyl acetate, amyl acetate, hexyl acetate, 2-ethylbutyl acetate, amyl formate, hexyl formate, isohexyl formate, butyl propionate, isobutyl propionate, propyl propionate, hexyl propionate, ethyl butyrate, ethyl isobutyrate, hexyl butyrate, isobutyl isobutyrate, ethyl hexanoate, methyl n-octanoate, and ethyl n-octanoate. (10) The organic solvent includes an acyclic ether solvent, The acyclic ether solvent has 5 or more carbon atoms, The treatment liquid according to any one of (1) to (7), wherein the absolute value of the difference between the boiling point of the acyclic ether solvent and the boiling point of the fluorine-containing solvent is 50° C. or more. (11) The treatment liquid according to (10), wherein the organic solvent contains at least one selected from the group consisting of diisoamyl ether, amyl ether, diisoamyl ether, and amyl ether. (12) The organic solvent includes an acyclic alcohol solvent, The acyclic alcohol solvent has 7 or more carbon atoms, The treatment liquid according to any one of (1) to (7), wherein the absolute value of the difference between the boiling point of the acyclic alcohol solvent and the boiling point of the fluorine-containing solvent is 100° C. or more. (13) The treatment liquid according to (12), wherein the organic solvent comprises at least one selected from the group consisting of 2,6-dimethyl-4-heptanol, 3-octanol, 2-ethylhexanol, 1-octanol, 2-octanol, 3,5-dimethyl-1-hexyn-3-ol, 1-octyn-3-ol, 3,7-dimethyl-3-octanol, 3,5,5-trimethyl-1-hexanol, 3-ethyl-3-pentanol-4-methylpentanol, and 1-heptanol. (14) The organic solvent includes an acyclic ketone solvent, The acyclic ketone solvent has 5 or more carbon atoms, The treatment liquid according to any one of (1) to (7), wherein the absolute value of the difference between the boiling point of the acyclic ketone solvent and the boiling point of the fluorine-containing solvent is 50° C. or more. (15) The treatment liquid according to (14), wherein the organic solvent comprises at least one selected from the group consisting of diisobutyl ketone, 3-octanone, 2,4-dimethyl-3-pentanone, 2,6-dimethyl-4-heptanone, 5-nonanone, and 2,5-dimethyl-3-hexanone. (16) The treatment liquid according to any one of (1) to (7), wherein the organic solvent contains a hydrocarbon solvent having 7 or more carbon atoms. (17) The treatment liquid according to (16), wherein the organic solvent contains at least one selected from the group consisting of decane, mesitylene, undecane, nonanone, 3-methylnonanone, 4-methylnonanone, and 5-methylnonane. (18) The treatment liquid according to any one of (1) to (17), wherein the actinic ray- or radiation-sensitive composition contains a resin having a hydroxystyrene-based repeating unit. (19) a resist film forming step of forming a resist film using an actinic ray- or radiation-sensitive composition; an exposure step of exposing the resist film; A pattern forming method comprising a treatment step of treating the exposed resist film with the treatment liquid according to any one of (1) to (18). (20) a resist film forming step of forming a resist film using an actinic ray- or radiation-sensitive composition; an exposure step of exposing the resist film; a processing step of processing the exposed resist film, The processing steps are: a developing step of developing with a developer; a rinsing step of cleaning with a rinse liquid, A pattern forming method, wherein the rinse liquid is the treatment liquid according to any one of (1) to (18). (21) The pattern forming method according to (20), wherein the developer contains an ester-based solvent. (22) The pattern formation method according to (21), wherein the ester-based solvent comprises at least one selected from the group consisting of butyl acetate, isobutyl acetate, tert-butyl acetate, sec-butyl acetate, amyl acetate, isoamyl acetate, amyl formate, isoamyl formate, hexyl formate, amyl propionate, isoamyl propionate, isopropyl propionate, propyl propionate, ethyl butyrate, ethyl isobutyrate, diethyl carbonate, dibutyl carbonate, butyl butanoate, isobutyl isobutyrate, ethyl isovalerate, butyl isovalerate, propyl heptanoate, ethyl heptanoate, butyl hexanoate, propyl hexanoate, and ethyl 3-methylvalerate. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a processing liquid which, when used for at least one of developing and cleaning (rinsing) a resist film, enables pattern formation with excellent resolution and is less likely to be charged when in contact with a fluorine-based resin. Furthermore, according to the present invention, a pattern forming method relating to the above-mentioned treatment liquid can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1A to 1C are micrographs showing examples of patterns produced in Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] In the present specification, when a group (atomic group) is described without specifying whether it is substituted or unsubstituted, it encompasses both unsubstituted and substituted groups, unless it is contrary to the spirit of the present invention. For example, the term "alkyl group" encompasses not only unsubstituted alkyl groups (unsubstituted alkyl groups) but also substituted alkyl groups (substituted alkyl groups). Furthermore, the term "organic group" in the present specification refers to a group containing at least one carbon atom.

[0013] As used herein, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet light typified by excimer lasers, extreme ultraviolet light (EUV light: Extreme Ultraviolet), X-rays, and electron beams (EB). As used herein, "light" refers to actinic rays or radiation.

[0014] Unless otherwise specified, the term "exposure" in this specification includes exposure to the bright line spectrum of a mercury lamp, far ultraviolet light typified by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, as well as drawing with particle beams such as electron beams and ion beams.

[0015] 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.

[0016] The bonding direction of the divalent groups shown in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the general formula "XYZ", Y may be -CO-O- or -O-CO-. In addition, the compound may be "X-CO-OZ" or "XO-CO-Z".

[0017] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic.

[0018] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0019] In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (hereinafter also referred to as "molecular weight distribution") (Mw / Mn) of a resin 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).

[0020] In this specification, the boiling point means the boiling point at 1 atmosphere.

[0021] In this specification, an organic solvent means an organic compound that is liquid at 25°C. The types and contents of organic compounds contained in the treatment liquid are measured, for example, by DI-MS (direct injection mass chromatography).

[0022] [Processing liquid] The treatment liquid of the present invention is a treatment liquid for resist film patterning, which is used to perform at least one of development and washing on a resist film obtained from an actinic ray- or radiation-sensitive composition (hereinafter also referred to as a "resist composition"). A characteristic feature of the treatment liquid of the present invention is that it contains a fluorine-containing solvent having 3 to 5 carbon atoms (hereinafter also simply referred to as a "fluorine-containing solvent") and an organic solvent other than the fluorine-containing solvent having 3 to 5 carbon atoms (hereinafter also simply referred to as a "second solvent"). The present inventors have found that the use of a fluorine-containing solvent prevents charging when the treatment liquid comes into contact with a fluorine-containing resin. However, the use of a fluorine-containing solvent deteriorates resolution. Therefore, they have found that the use of an organic solvent other than a fluorine-containing solvent improves resolution while preventing charging.

[0023] In the treatment liquid, it is preferable to select a fluorine-based solvent having a boiling point lower than that of the second solvent. When the boiling point of the fluorine-containing solvent is lower than that of the second solvent, the fluorine-containing solvent is preferentially evaporated during drying after the treatment with the treatment liquid (e.g., rinsing treatment), and the concentration of the second solvent on the formed pattern increases, thereby maximizing the effect of the second solvent and more significantly suppressing pattern collapse, particularly in dense patterns.

[0024] The fluorine-containing solvent and the second solvent contained in the treatment liquid of the present invention will be described in detail below.

[0025] [Fluorinated solvents with 3 to 5 carbon atoms (fluorinated solvents)] The treatment liquid of the present invention contains a fluorine-based solvent. The fluorine-based solvent has 3 to 5 carbon atoms, preferably 4 to 5, and more preferably 5, in that the effects of the present invention are more excellent. A fluorine-based solvent is an organic solvent containing at least one fluorine atom in the molecule, and is preferably a hydrocarbon having 3 to 5 carbon atoms and having at least one fluorine atom.

[0026] The number of fluorine atoms contained in the fluorine-based solvent is preferably at least twice the number of carbon atoms contained in the fluorine-based solvent. There is no particular upper limit, but the number is preferably 3 times or less, and more preferably 2.5 times or less.

[0027] The fluorine-based solvent is preferably a compound represented by formula (a), more specifically, 2H,3H-decafluoropentane or 1H-undecafluoropentane.

[0028] [ka]

[0029] In formula (a), X 1 ~X 6 each independently represents a hydrogen atom or a fluorine atom. X 1 ~X 6 Among these, one or more represent a fluorine atom, preferably three or more represent a fluorine atom, and more preferably five or more represent a fluorine atom.

[0030] Y represents an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom. The alkylene group which may have a fluorine atom, represented by Y, may have a linear or branched chain structure, and among these, the alkylene group preferably has a linear structure. The alkylene group represented by Y has 1 to 3 carbon atoms, preferably 2 to 3 carbon atoms, and more preferably 3 carbon atoms. The alkylene group preferably contains fluorine atoms, and the alkylene group preferably contains 2 to 6 fluorine atoms, and more preferably 2 to 4 fluorine atoms.

[0031] The boiling point (°C) of the fluorine-based solvent is preferably 40°C or higher. There is no particular upper limit, but it is preferably 100°C or lower, more preferably 80°C or lower, and even more preferably 60°C or lower. The above boiling point is the boiling point at 1 atmosphere.

[0032] The fluorine-based solvents may be used alone or in combination of two or more.

[0033] The content of the fluorine-based solvent is not particularly limited, and is often 5 to 95% by mass relative to the total mass of the treatment liquid. In terms of better effects of the present invention, the content is preferably 10 to 80% by mass, more preferably 10 to 70% by mass, and even more preferably 10 to 50% by mass.

[0034] [Organic solvents other than fluorinated solvents with 3 to 5 carbon atoms (secondary solvents)] The treatment liquid of the present invention contains a second solvent. The second solvent may be any solvent other than a fluorine-containing solvent having 3 to 5 carbon atoms, and may be a solvent containing a fluorine atom or a solvent not containing a fluorine atom (a non-fluorine-containing solvent). A non-fluorine-containing solvent refers to an organic solvent that does not have a fluorine atom in its molecule. The second solvent preferably contains a hydrocarbon that may have a heteroatom. The heteroatom may be any atom other than carbon or hydrogen atoms, such as oxygen, nitrogen, and sulfur atoms.

[0035] The second solvent is preferably a non-fluorinated solvent. Examples of the second solvent include ester solvents, ether solvents, alcohol solvents, ketone solvents, and hydrocarbon solvents. The second solvent may have a linear, branched, or cyclic structure. Among these, in terms of achieving better effects of the present invention, the second solvent is preferably at least one selected from the group consisting of acyclic ester solvents, acyclic ether solvents, acyclic alcohol solvents, acyclic ketone solvents, and hydrocarbon solvents, and more preferably an acyclic ester solvent, an acyclic ether solvent, an acyclic alcohol solvent, or an acyclic ketone solvent.

[0036] <Ester-based solvent> The second solvent may contain an ester-based solvent. In this specification, the term "ester-based solvent" also includes carbonate-based solvents.

[0037] Examples of ester-based solvents include isopropyl propionate, sec-butyl acetate, isoamyl formate, butyl acetate, diethyl carbonate, butyl butyrate, amyl butyrate, isobutyl butyrate, isobutyl acetate, tert-butyl acetate, isoamyl acetate, amyl acetate, hexyl acetate, 2-ethylbutyl acetate, amyl formate, hexyl formate, isohexyl formate, butyl propionate, isobutyl propionate, propyl propionate, hexyl propionate, ethyl butyrate, ethyl isobutyrate, hexyl butyrate, isobutyl isobutyrate, ethyl hexanoate, methyl n-octanoate, ethyl n-octanoate, and methyl benzoate. Among these, in terms of more excellent effects of the present invention, at least one selected from the group consisting of isopropyl propionate, sec-butyl acetate, isoamyl formate, butyl acetate, diethyl carbonate, butyl butyrate, amyl butyrate, isobutyl butyrate, isobutyl acetate, tert-butyl acetate, isoamyl acetate, amyl acetate, hexyl acetate, 2-ethylbutyl acetate, amyl formate, hexyl formate, isohexyl formate, butyl propionate, isobutyl propionate, propyl propionate, hexyl propionate, ethyl butyrate, ethyl isobutyrate, hexyl butyrate, isobutyl isobutyrate, ethyl hexanoate, methyl n-octanoate, and ethyl n-octanoate is preferred. Isopropyl propionate, sec-butyl acetate, isoamyl formate, butyl acetate, diethyl carbonate, butyl butyrate, or amyl butyrate is more preferred.

[0038] The ester solvent may have a linear structure or a branched structure. The ester solvent may have a cyclic structure. In particular, it is preferable that the ester solvent does not have a cyclic structure, in order to obtain a more excellent effect of the present invention. In other words, it is preferable that the ester solvent is a non-cyclic ester solvent (an ester solvent having no cyclic structure). The ester solvent may have, for example, a linear alkyl group or a branched alkyl group. In particular, the ester-based solvent is preferably composed only of an ester bond and a linear or branched alkyl group, in terms of achieving better effects of the present invention.

[0039] The number of carbon atoms in the ester solvent is not particularly limited, but preferably is 5 or more. The upper limit is not particularly limited, but is preferably 15 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. The preferred range of the carbon number of the acyclic ester solvent is the same as the preferred range of the carbon number of the ester solvent described above.

[0040] The absolute value of the difference between the boiling point (°C) of the ester solvent and the boiling point (°C) of the fluorine-containing solvent is not particularly limited, but is preferably 50°C or higher. The upper limit is not particularly limited, but is preferably 200°C or lower, more preferably 150°C or lower, and even more preferably 120°C or lower. The above boiling points are those at 1 atmosphere. The preferred range of the absolute value of the difference between the boiling point of the acyclic ester solvent and the boiling point of the fluorine-containing solvent is the same as the preferred range of the absolute value of the difference between the boiling point of the ester solvent and the boiling point of the fluorine-containing solvent described above.

[0041] The ester solvents may be used alone or in combination of two or more.

[0042] <Ether-based solvents> The second solvent may include an ether-based solvent. Examples of the ether solvent include diisoamyl ether, amyl ether, diisoamyl ether, amyl ether, and anisole. Among these, diisoamyl ether, amyl ether, diisoamyl ether, or amyl ether is preferred as the ether solvent in terms of achieving the effects of the present invention more excellently.

[0043] The ether-based solvent may have a linear or branched structure. The ether-based solvent may have a cyclic structure. In particular, it is preferable that the ether-based solvent does not have a cyclic structure, in order to obtain a more excellent effect of the present invention. In other words, it is preferable that the ether-based solvent is a non-cyclic ether-based solvent (an ether-based solvent having no cyclic structure). The ether solvent may have, for example, a linear alkyl group or a branched alkyl group. In particular, the ether-based solvent is preferably composed only of an ether bond and a linear or branched alkyl group, in terms of achieving better effects of the present invention.

[0044] The number of carbon atoms in the ether solvent is not particularly limited, but is preferably 5 or more, more preferably 8 or more, and even more preferably 10 or more. The upper limit is not particularly limited, but is preferably 20 or less, more preferably 17 or less, and even more preferably 15 or less. The preferred range of the carbon number of the acyclic ether solvent is the same as the preferred range of the carbon number of the ether solvent described above.

[0045] The absolute value of the difference between the boiling point (°C) of the ether-based solvent and the boiling point (°C) of the fluorine-based solvent is not particularly limited, but is preferably 50°C or higher, more preferably 90°C or higher, and even more preferably over 105°C. There is no particular upper limit, but it is preferably 200°C or lower, more preferably 150°C or lower. The above boiling points are those at 1 atmosphere. The preferred range of the absolute value of the difference between the boiling point of the acyclic ether solvent and the boiling point of the fluorine-containing solvent is the same as the preferred range of the absolute value of the difference between the boiling point of the ether solvent and the boiling point of the fluorine-containing solvent described above.

[0046] The ether solvents may be used alone or in combination of two or more.

[0047] <Alcohol-based solvent> The second solvent may include an alcohol-based solvent.

[0048] Examples of alcohol-based solvents include 2,6-dimethyl-4-heptanol, 3-octanol, 2-ethylhexanol, 1-octanol, 2-octanol, 3,5-dimethyl-1-hexyn-3-ol, 1-octyn-3-ol, 3,7-dimethyl-3-octanol, 3,5,5-trimethyl-1-hexanol, 3-ethyl-3-pentanol-4-methylpentanol, and 1-heptanol. Among these, 2,6-dimethyl-4-heptanol or 3-octanol is preferred as the alcohol solvent in terms of achieving better effects of the present invention.

[0049] The alcohol-based solvent may have a linear or branched structure. The alcohol-based solvent may have a cyclic structure. In particular, it is preferable that the alcohol-based solvent does not have a cyclic structure, in that the effects of the present invention are more excellent. In other words, it is preferable that the alcohol-based solvent is an acyclic alcohol-based solvent (an alcohol-based solvent without a cyclic structure). The alcohol-based solvent may have, for example, a linear alkyl group or a branched alkyl group. In order to obtain a more excellent effect of the present invention, the alcohol-based solvent is preferably composed of only a hydroxyl group and a linear or branched alkyl group.

[0050] The number of carbon atoms in the alcohol-based solvent is not particularly limited, but is preferably 7 or more, more preferably 8 or more. The upper limit is not particularly limited, but is preferably 20 or less, more preferably 17 or less, and even more preferably 15 or less. The preferred range of the carbon number of the acyclic alcohol-based solvent is the same as the preferred range of the carbon number of the alcohol-based solvent described above.

[0051] The absolute value of the difference between the boiling point (°C) of the alcohol-based solvent and the boiling point (°C) of the fluorine-based solvent is not particularly limited, but is preferably 100°C or higher, more preferably 120°C or higher. There is no particular upper limit, but it is preferably 200°C or lower, more preferably 150°C or lower. The above boiling points are those at 1 atmosphere. The preferred range of the absolute value of the difference between the boiling point of the acyclic alcohol solvent and the boiling point of the fluorine-containing solvent is the same as the preferred range of the absolute value of the difference between the boiling point of the alcohol solvent and the boiling point of the fluorine-containing solvent described above.

[0052] The alcohol-based solvents may be used alone or in combination of two or more.

[0053] <Ketone-based solvents> The second solvent may include a ketone-based solvent.

[0054] Examples of ketone solvents include diisobutyl ketone, 3-octanone, 2,4-dimethyl-3-pentanone, 2,6-dimethyl-4-heptanone, 5-nonanone, and 2,5-dimethyl-3-hexanone. Among these, diisobutyl ketone, 3-octanone, or 2,4-dimethyl-3-pentanone is preferred as the ketone solvent in terms of achieving better effects of the present invention.

[0055] The ketone solvent may have a linear or branched structure. The ketone solvent may have a cyclic structure. In particular, it is preferable that the ketone solvent does not have a cyclic structure, in order to obtain better effects of the present invention. In other words, it is preferable that the ketone solvent is an acyclic ketone solvent (a ketone solvent without a cyclic structure). The ketone solvent may have, for example, a linear alkyl group or a branched alkyl group. In order to obtain a more excellent effect of the present invention, the ketone solvent is preferably composed of only a ketone bond and a linear or branched alkyl group.

[0056] The number of carbon atoms in the ketone solvent is not particularly limited, but is preferably 5 or more, more preferably 7 or more. The upper limit is not particularly limited, but is preferably 20 or less, more preferably 17 or less, and even more preferably 15 or less. The preferred range of the carbon number of the acyclic ketone solvent is the same as the preferred range of the carbon number of the ketone solvent described above.

[0057] The absolute value of the difference between the boiling point (°C) of the ketone solvent and the boiling point (°C) of the fluorine-containing solvent is not particularly limited, but is preferably 50°C or higher, more preferably 70°C or higher. There is no particular upper limit, but it is preferably 200°C or lower, more preferably 150°C or lower. The above boiling points are those at 1 atmosphere. The preferred range of the absolute value of the difference between the boiling point of the acyclic ketone solvent and the boiling point of the fluorine-containing solvent is the same as the preferred range of the absolute value of the difference between the boiling point of the ketone solvent and the boiling point of the fluorine-containing solvent described above.

[0058] The ketone solvents may be used alone or in combination of two or more.

[0059] <Hydrocarbon solvents> The second solvent may include a hydrocarbon solvent.

[0060] Examples of aromatic solvents include decane, mesitylene, undecane, nonanone, 3-methylnonanone, 4-methylnonanone, and 5-methylnonane. Among these, decane or mesitylene is preferred as the aromatic solvent in that the effects of the present invention are more excellent.

[0061] The hydrocarbon solvent may have a linear, branched, or cyclic structure. The hydrocarbon solvent may have, for example, a linear alkyl group, a branched alkyl group, an alicyclic group, or an aromatic group. Among these, the hydrocarbon solvent preferably has a linear alkyl group or an aromatic group, in terms of achieving better effects of the present invention. In order to obtain a more excellent effect of the present invention, the hydrocarbon solvent is preferably composed only of an aromatic ring, or a linear or branched alkyl group.

[0062] The number of carbon atoms in the hydrocarbon solvent is not particularly limited, but is preferably 7 or more, more preferably 8 or more. The upper limit is not particularly limited, but is preferably 20 or less, more preferably 17 or less, and even more preferably 15 or less.

[0063] The absolute value of the difference between the boiling point (°C) of the hydrocarbon solvent and the boiling point (°C) of the fluorine-containing solvent is not particularly limited, but is preferably 100°C or higher, more preferably 105°C or higher. There is no particular upper limit, but it is preferably 200°C or lower, more preferably 150°C or lower. The above boiling points are those at 1 atmosphere.

[0064] The hydrocarbon solvents may be used alone or in combination of two or more.

[0065] The content of the second solvent is not particularly limited, and is often 5 to 95% by mass relative to the total mass of the treatment liquid. In terms of better effects of the present invention, the content is preferably 20 to 90% by mass, more preferably 30 to 90% by mass, and even more preferably 50 to 90% by mass.

[0066] [Other ingredients] The treatment liquid of the present invention may contain other components in addition to those described above.

[0067] <Metal components> The treatment liquid may contain a metal component. Examples of the metal component include metal particles and metal ions, and for example, the content of the metal component refers to the total content of the metal particles and metal ions. The treatment liquid may contain either metal particles or metal ions, or may contain both.

[0068] Examples of metal atoms contained in the metal component include metal atoms selected from the group consisting of Ag, Al, As, Au, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, Ge, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sn, Sr, Ti, and Zn. The metal component may contain one type of metal atom or two or more types of metal atoms. The metal particles may be a simple substance or an alloy, or may exist in a form in which the metal is associated with an organic substance. The metal component may be a metal component that is inevitably contained in each component (raw material) contained in the treatment liquid, a metal component that is inevitably contained during the production, storage, and / or transportation of the treatment liquid, or a metal component that is intentionally added.

[0069] When the treatment liquid contains a metal component, the content of the metal component is preferably more than 0 mass ppt and not more than 1 mass ppm, more preferably more than 0 mass ppt and not more than 10 mass ppb, and even more preferably more than 0 mass ppt and not more than 10 mass ppt, relative to the total mass of the treatment liquid. The type and content of metal components in the treatment liquid can be measured by ICP-MS (inductively coupled plasma mass spectrometry).

[0070] <Ionic liquid> The treatment liquid of the present invention may contain the following ionic liquid. Note that when the treatment liquid contains an ionic liquid, the ionic liquid is not included in the fluorine-based solvent and the second solvent. The ionic liquid has, for example, an aromatic ion such as a pyridinium ion or an imidazolium ion, or an aliphatic amine ion such as a trimethylhexylammonium ion as a cation. - , CH3CO2 - , BF6 - , or PF6 - Inorganic ion systems such as (CF3SO2)2N - , CF3CO2 - , or CF3SO2 - and quaternary ammonium salt-based ionic liquids.

[0071] Commercially available ionic liquids include, for example, quaternary ammonium salt-based ionic liquids such as IL-P14 and IL-A2 (manufactured by Koei Chemical Industry Co., Ltd.); and Elegan SS-100 (manufactured by Nippon Oil & Fats Co., Ltd.). The ionic liquid may be used alone or in combination of two or more kinds.

[0072] When the treatment liquid of the present invention contains an ionic liquid, the content of the ionic liquid is preferably 0.5 to 15 mass %, more preferably 1 to 10 mass %, and even more preferably 1 to 5 mass %, relative to the total mass of the treatment liquid.

[0073] <Surfactant> The treatment liquid of the present invention may contain a surfactant. When the processing liquid contains a surfactant, the wettability of the processing liquid with respect to the resist film is improved, and development and / or rinsing proceeds more effectively. As the surfactant, the same surfactants that can be contained in the resist composition described below can be used. The surfactant may be used alone or in combination of two or more kinds. When the treatment liquid of the present invention contains a surfactant, the content of the surfactant is preferably 0.001 to 5 mass %, more preferably 0.005 to 2 mass %, and even more preferably 0.01 to 0.5 mass %, relative to the total mass of the treatment liquid.

[0074] <Antioxidants> The treatment liquid of the present invention may contain an antioxidant. The antioxidant is preferably an amine-based antioxidant or a phenol-based antioxidant. The antioxidants may be used alone or in combination of two or more. When the treatment liquid of the present invention contains an antioxidant, the content of the antioxidant is preferably 0.0001 to 1 mass %, more preferably 0.0001 to 0.1 mass %, and even more preferably 0.0001 to 0.01 mass %, relative to the total mass of the treatment liquid.

[0075] <Basic compounds> The treatment liquid of the present invention may contain a basic compound. Specific examples of the basic compound include the compounds exemplified below as acid diffusion controllers that can be contained in the resist composition. The basic compounds may be used alone or in combination of two or more. When the processing liquid of the present invention contains a basic compound, the content of the basic compound is preferably 10% by mass or less, and more preferably 0.5 to 5% by mass, based on the total mass of the processing liquid. In the present invention, the basic compounds may be used alone or in combination of two or more compounds having different chemical structures.

[0076] <Organic substances with a boiling point of 300°C or higher> When a processing liquid containing organic substances with a boiling point of 300°C or higher is applied to a semiconductor device manufacturing process, the organic substances with a high boiling point may remain without volatilizing, which may cause defects in the substrate. The organic matter with a boiling point of 300°C or higher is thought to be, for example, a resin component or plasticizer contained in a plastic material (e.g., an O-ring) used in a component of the manufacturing equipment, and is presumed to have leached into the liquid at some point during the manufacturing process. When the treatment liquid contains an organic substance having a boiling point of 300°C or higher, the content of the organic substance having a boiling point of 300°C or higher is preferably 0.001 to 50 mass ppm, more preferably 0.001 to 30 mass ppm, even more preferably 0.001 to 15 mass ppm, particularly preferably 0.001 to 10 mass ppm, and most preferably 0.001 to 1 mass ppm, relative to the total mass of the treatment liquid, from the viewpoint of suppressing defects in substrates when used in a semiconductor device manufacturing process.

[0077] It is preferable that the content of the organic substance having a boiling point of 300°C or higher is 30 mass ppm or less relative to the total mass of the treatment liquid, in order to prevent the organic substance from remaining on the substrate surface without volatilizing and causing defects when the treatment liquid is used as a developer and brought into contact with a substrate. It is further preferable that the content of the organic substance having a boiling point of 300°C or higher is 15 mass ppm or less relative to the total mass of the treatment liquid, in order to prevent the organic substance having a boiling point of 300°C or higher from remaining on the substrate even after a baking step, for example, when the treatment liquid is used as a developer and brought into contact with a substrate, thereby suppressing the cause of defects (poor development). Organic substances with a boiling point of 300°C or higher that may be contained in the treatment liquid include components such as dioctyl phthalate (DOP, boiling point 385°C) that elutes from O-rings, diisononyl phthalate (DINP, boiling point 403°C), dioctyl adipate (DOA, boiling point 335°C), dibutyl phthalate (DBP, boiling point 340°C), and ethylene propylene rubber (EPDM, boiling point 300-450°C).

[0078] As a method for keeping the content of organic substances having a boiling point of 300° C. or higher in the treatment liquid within the above range, the methods mentioned in the purification step described below can be mentioned.

[0079] [Pattern Forming Method] The present invention also relates to a pattern forming method using the above-mentioned treatment liquid. The pattern formation method is, for example, (i) a resist film forming step of forming a resist film using a resist composition; (ii) an exposure step of exposing the resist film to light; (iii) a treatment step of treating the exposed resist film with the treatment liquid.

[0080] Each step of the pattern forming method will be described below. As examples of the processing steps, the developing step and the rinsing step will be described.

[0081] <(i) Resist film forming process> The resist film forming step is a step of forming a resist film using a resist composition. When forming a resist film using the resist composition, for example, the components described below are dissolved in a solvent to prepare a resist composition, and after filtering as necessary, the resist composition is applied to a support (substrate) to form a resist film. 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 material is preferably polytetrafluoroethylene, polyethylene, or nylon.

[0082] The resist composition is applied onto a support (substrate) by a suitable application method such as a spinner. The coating film (coating film of the applied resist composition) is then dried to form a resist film. If necessary, various undercoating films (inorganic film, organic film, and anti-reflective film) may be formed below the resist film.

[0083] The support on which the resist film is formed is not particularly limited, and substrates that are generally used in the manufacturing process of semiconductors such as ICs, or circuit boards such as liquid crystal or thermal heads, as well as other lithography processes for photofabrication, can be used. Specific examples of the support include inorganic substrates such as silicon, SiO2, and SiN. The substrate includes a semiconductor substrate made of a single layer and a semiconductor substrate made of a multilayer. The material constituting the single-layer semiconductor substrate is not particularly limited, but is generally preferably silicon, silicon germanium, a III-V compound such as GaAs, or any combination thereof. The multi-layer semiconductor substrate may have any configuration, and may include, for example, exposed integrated circuit structures, such as interconnect features, such as metal lines and dielectric materials, on a semiconductor substrate such as silicon. Metals and alloys used in the interconnect structures include, but are not limited to, aluminum and copper, alloyed aluminum, copper, titanium, tantalum, cobalt, silicon, titanium nitride, tantalum nitride, and tungsten. The semiconductor substrate may also include layers such as interlayer dielectric layers, silicon oxide, silicon nitride, silicon carbide, and carbon-doped silicon oxide.

[0084] As a drying method, a method of drying by heating is generally used. The heating temperature is preferably 80 to 180°C, more preferably 80 to 150°C, even more preferably 80 to 140°C, and particularly preferably 80 to 130°C. The heating time is preferably from 30 to 1000 seconds, more preferably from 60 to 800 seconds, and even more preferably from 60 to 600 seconds.

[0085] The thickness of the resist film is generally 200 nm or less, and preferably 100 nm or less. For example, to resolve a 1:1 line and space pattern of 30 nm or less, the resist film preferably has a thickness of 50 nm or less. If the thickness is 50 nm or less, pattern collapse is less likely to occur when the developing step described below is applied, and better resolution performance can be obtained. The film thickness is preferably 15 to 70 nm, more preferably 15 to 65 nm, in terms of better etching resistance and resolution.

[0086] If necessary, a resist underlayer film (e.g., SOG (Spin On Glass), SOC (Spin On Carbon), and an anti-reflective film) may be formed between the resist film and the support. Known organic or inorganic materials can be appropriately used as the material for the resist underlayer film. A protective film (top coat) may be formed on the resist film. Known materials can be used as the protective film. For example, protective film-forming compositions disclosed in U.S. Patent Application Publication No. 2007 / 0178407, U.S. Patent Application Publication No. 2008 / 0085466, U.S. Patent Application Publication No. 2007 / 0275326, U.S. Patent Application Publication No. 2016 / 0299432, U.S. Patent Application Publication No. 2013 / 0244438, and International Patent Application Publication No. 2016 / 157988A are suitable. Protective film-forming compositions preferably contain the acid diffusion controller described above. Alternatively, an upper layer film may be formed based on the description in paragraphs

[0072] to

[0082] of JP-A-2014-059543. The thickness of the protective film is preferably from 10 to 200 nm, more preferably from 20 to 100 nm, and even more preferably from 40 to 80 nm.

[0087] <(ii) Exposure process> In the pattern forming method, the exposure method in the (ii) exposure step may be immersion exposure. The pattern formation method preferably includes a (iv) pre-baking (PB: Pre-Bake, hereinafter also referred to as "post-coating bake") step prior to the (ii) exposure step. The pattern formation method preferably includes a (v) post-exposure bake (PEB) step after the (ii) exposure step and before the (iii) development step. The pattern formation method may include the exposure step (ii) multiple times. The pattern formation method may include the (iv) pre-heating step multiple times. The pattern formation method may include the post-exposure baking step (v) multiple times.

[0088] In the pattern forming method, (ii) the exposure step can be carried out by a generally known method.

[0089] The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C in both (iv) the pre-baking step and (v) the post-exposure baking step. The heating time is preferably from 30 to 1000 seconds, more preferably from 60 to 800 seconds, and even more preferably from 60 to 600 seconds in both the (iv) pre-baking step and the (v) post-exposure baking step. Heating can be carried out by means provided in the exposure device and the development device, and may also be carried out using a hot plate or the like.

[0090] The wavelength of the light source used in the exposure step is not limited, and examples include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV light), X-rays, and electron beams. Among these, far ultraviolet light is preferred, and its wavelength is preferably 250 nm or less, more preferably 220 nm or less, and even more preferably 1 to 200 nm. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), X-rays, EUV (13 nm), and electron beams. KrF excimer laser, ArF excimer laser, EUV, or electron beams are preferred, and EUV or electron beams are more preferred.

[0091] <(iii) Step of treating the exposed film> (iii) The step of treating the exposed film usually includes (vi) a developing step (developing step) of developing with a developer, and (vii) a rinsing step (rinsing step) of rinsing with a rinse solution. The processing liquid of the present invention may be used as a developer in the development step or as a rinse liquid in the rinse step, and is particularly preferably used as a rinse liquid in the rinse step. When the processing liquid of the present invention is used as a rinsing liquid in the rinsing step, it is preferable to use a processing liquid other than the processing liquid of the present invention as a developer in the developing step.

[0092] (Development process) The developing step is a step of developing the exposed resist film with a developer.

[0093] Examples of development methods include a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is piled up on the surface of the substrate by surface tension and left to stand for a certain period of time (puddle method), a method in which the developer is sprayed onto the surface of the substrate (spray method), and a method in which the developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispensing nozzle is scanned at a constant speed (dynamic dispense method). After the development step, a step of stopping the development while replacing the solvent with another solvent may be carried out. The development time 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, more preferably from 15 to 35°C.

[0094] As the developer, the above-mentioned processing solution may be used, or other developers may be used. In addition to development using a processing solution, development using an alkaline developer may also be carried out (so-called double development).

[0095] Other developers Other developers (developers other than the processing solution of the present invention) will be described below. The vapor pressure of the organic solvent used in the developer (the overall vapor pressure in the case of a mixed solvent) is preferably 5 kPa or less, more preferably 3 kPa or less, and even more preferably 2 kPa or less at 20° C. By setting the vapor pressure of the organic solvent to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, improving the temperature uniformity within the substrate surface and, as a result, improving the dimensional uniformity within the substrate surface. The organic solvent used in the developer is not particularly limited, but examples thereof include ester-based solvents, ketone-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

[0096] The developer preferably contains one or more solvents selected from the group consisting of ketone-based solvents, ester-based solvents, alcohol-based solvents, and ether-based solvents.

[0097] Examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, tert-butyl acetate, sec-butyl acetate, pentyl acetate, propyl acetate, isopropyl acetate, amyl acetate (pentyl acetate), isoamyl acetate (isopentyl acetate, 3-methylbutyl acetate), 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate (PGMEA; also known as 1-methoxy-2-acetoxypropane), ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, and diethylene glycol monoethyl ether. teracetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3- Methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, amyl formate, isoamyl formate, hexyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, diethyl carbonate, dibutyl carbonate, butyl butanoate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate,Ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, amyl propionate, isoamyl propionate, hexyl propionate, ethyl butyrate, ethyl isobutyrate, butyl butyrate, isobutyl butyrate, pentyl butyrate, hexyl butyrate, isobutyl isobutyrate, ethyl isovalerate, butyl isovalerate, propyl valerate, isopropyl valerate, butyl valerate, pentyl valerate, ethyl hexanoate, propyl hexanoate, hexanoate Examples of the hydroxypropyl methyl ester include butyl hexanoate, isobutyl hexanoate, methyl heptanoate, ethyl heptanoate, propyl heptanoate, cyclohexyl acetate, cycloheptyl acetate, 2-ethylhexyl acetate, cyclopentyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, and ethyl 3-methylvalerate. Of these, butyl acetate, isobutyl acetate, tert-butyl acetate, sec-butyl acetate, amyl acetate, isoamyl acetate, amyl formate, isoamyl formate, hexyl formate, amyl propionate, isoamyl propionate, isopropyl propionate, propyl propionate, ethyl butyrate, ethyl isobutyrate, diethyl carbonate, dibutyl carbonate, butyl butanoate, isobutyl isobutyrate, ethyl isovalerate, butyl isovalerate, propyl heptanoate, ethyl heptanoate, butyl hexanoate, propyl hexanoate, or ethyl 3-methylvalerate is preferred.

[0098] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, and γ-butyrolactone. Of these, 2-heptanone is preferred.

[0099] Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-decanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and 3- Methyl-3-pentanol, cyclopentanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 5-methyl-2-hexanol, 4-methyl-2-hexanol, 4,5-dimethyl-2-hexal, 6-methyl-2 Examples of the solvent include alcohols (monohydric alcohols) such as 1-heptanol, 7-methyl-2-octanol, 8-methyl-2-nonal, 9-methyl-2-decanol, and 3-methoxy-1-butanol; glycol solvents such as ethylene glycol, diethylene glycol, and triethylene glycol; and glycol ether solvents containing hydroxyl groups such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME; also known as 1-methoxy-2-propanol), diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethylbutanol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and propylene glycol monophenyl ether. Among these, glycol ether solvents are preferred.

[0100] Examples of the ether solvent include, in addition to the above-mentioned glycol ether solvents containing a hydroxyl group, glycol ether solvents not containing a hydroxyl group, such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; aromatic ether solvents, such as anisole and phenetole; dioxane, tetrahydrofuran, tetrahydropyran, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, 1,4-dioxane, and isopropyl ether. Among these, glycol ether solvents and aromatic ether solvents, such as anisole, are preferred.

[0101] Examples of amide solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone.

[0102] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as pentane, hexane, octane, nonane, decane, dodecane, undecane, hexadecane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane, and perfluoroheptane; and aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene, and dipropylbenzene. In addition, unsaturated hydrocarbon solvents can also be used as the hydrocarbon solvent, and examples thereof include unsaturated hydrocarbon solvents such as octene, nonene, decene, undecene, dodecene, and hexadecene. The number of double bonds or triple bonds in the unsaturated hydrocarbon solvent is not particularly limited, and they may be located at any position in the hydrocarbon chain. In addition, when the unsaturated hydrocarbon solvent has a double bond, it may contain a mixture of cis and trans isomers. The aliphatic hydrocarbon solvent may be a mixture of compounds having the same carbon number but different structures. For example, when decane is used as the aliphatic hydrocarbon solvent, the aliphatic hydrocarbon solvent may contain compounds having the same carbon number but different structures, such as 2-methylnonane, 2,2-dimethyloctane, 4-ethyloctane, and isooctane. The compound having the same carbon number but different structure may contain only one type, or may contain multiple types as described above.

[0103] As the developer, an ester solvent having 6 or more carbon atoms (preferably 6 to 14, more preferably 6 to 12, and even more preferably 6 to 10) and 2 or less heteroatoms is preferred, as this can further suppress swelling of the resist film when EUV light and electron beams are used in the exposure step described above. The heteroatom may be any atom other than carbon and hydrogen atoms, and examples thereof include oxygen atoms, nitrogen atoms, sulfur atoms, etc. The number of heteroatoms is preferably 2 or less. Specific examples of ester solvents having 6 or more carbon atoms and 2 or less heteroatoms are preferably those selected from the group consisting of butyl acetate, amyl acetate, isoamyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, heptyl propionate, butyl butanoate, butyl isobutanoate, and isobutyl isobutanoate, with isoamyl acetate or butyl isobutanoate being more preferred.

[0104] When EUV light and electron beams are used in the exposure step described above, in order to further suppress swelling of the resist film, a mixed solvent of an ester solvent and a hydrocarbon solvent, or a mixed solvent of a ketone solvent and a hydrocarbon solvent may be used as the developer instead of the ester solvent having 6 or more carbon atoms and 2 or less heteroatoms described above.

[0105] In the mixed solvent, the content of the hydrocarbon solvent is not particularly limited since it depends on the solubility of the resist film in the solvent, and the required amount may be determined by appropriate preparation.

[0106] In the mixed solvent of an ester solvent and a hydrocarbon solvent, isoamyl acetate is preferred as the ester solvent, and saturated hydrocarbon solvents (e.g., octane, nonane, decane, dodecane, undecane, and hexadecane) are preferred as the hydrocarbon solvent because they allow for easy adjustment of the solubility of the resist film.

[0107] In the mixed solvent of a ketone solvent and a hydrocarbon solvent, examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, 2,5-dimethyl-4-hexanone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate, with diisobutyl ketone or 2,5-dimethyl-4-hexanone being preferred. As the hydrocarbon solvent, saturated hydrocarbon solvents (such as octane, nonane, decane, dodecane, undecane, and hexadecane) are preferred because they allow for easy adjustment of the solubility of the resist film.

[0108] The developer may contain a mixture of two or more of the above solvents, or may contain water or a solvent other than the above solvents. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, and even more preferably less than 10% by mass, and particularly preferably substantially no water. The content of the organic solvent in the organic developer is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass, based on the total mass of the developer.

[0109] The developer may contain an appropriate amount of a known surfactant, if necessary.

[0110] The content of the surfactant is usually from 0.001 to 5% by mass, preferably from 0.005 to 2% by mass, and more preferably from 0.01 to 0.5% by mass, based on the total amount of the developer.

[0111] The developer may contain a basic compound. Specific examples of the basic compound include the compounds exemplified below as acid diffusion controllers that can be contained in the resist composition.

[0112] As the organic solvent used as the developer, in addition to the above-mentioned ester-based solvents, solvents represented by the following general formula (S1) or (S2) are also preferred. As the ester solvent, a solvent represented by general formula (S1) is more preferable, alkyl acetate is further preferable, and butyl acetate, amyl acetate (pentyl acetate) or isoamyl acetate (isopentyl acetate) is particularly preferable.

[0113] RC(=O)-O-R' General formula (S1)

[0114] In general formula (S1), R and R' each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxyl group, an alkoxycarbonyl group, a carboxyl group, a hydroxyl group, a cyano group, or a halogen atom. R and R' may bond to each other to form a ring. The alkyl group, alkoxyl group, and alkoxycarbonyl group represented by R and R' preferably have 1 to 15 carbon atoms, and the cycloalkyl group preferably has 3 to 15 carbon atoms. The alkyl group, cycloalkyl group, alkoxyl group, and alkoxycarbonyl group represented by R and R', as well as the ring formed by bonding R and R' together, may have a substituent. The substituent is not particularly limited, and examples thereof include a hydroxyl group, a group containing a carbonyl group (e.g., an acyl group, an aldehyde group, an alkoxycarbonyl, etc.), and a cyano group. Of these, R and R' are preferably a hydrogen atom or an alkyl group.

[0115] Examples of the solvent represented by general formula (S1) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, and ethyl 2-hydroxypropionate.

[0116] Of these, unsubstituted alkyl groups are preferred as R and R'. The solvent represented by general formula (S1) is preferably an alkyl acetate, more preferably butyl acetate, amyl acetate (pentyl acetate) or isoamyl acetate (isopentyl acetate), and even more preferably isoamyl acetate.

[0117] When the developer contains a solvent represented by general formula (S1), the developer may further contain one or more other organic solvents (hereinafter also referred to as "co-solvents"). The co-solvents are not particularly limited as long as they can be mixed with the solvent represented by general formula (S1) without separation, and examples thereof include solvents selected from the group consisting of ester solvents other than the solvent represented by general formula (S1), ketone solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. The solvent may be one kind or two or more kinds, but it is preferable to use one kind in order to obtain stable performance. When the developer is a mixed solvent of the solvent represented by general formula (S1) and one kind of co-solvent, the mass ratio of the content of the solvent represented by general formula (S1) to the co-solvent [mass content of solvent represented by general formula (S1) / mass content of co-solvent] is usually 20 / 80 to 99 / 1, preferably 50 / 50 to 97 / 3, more preferably 60 / 40 to 95 / 5, and even more preferably 60 / 40 to 90 / 10.

[0118] As the organic solvent used as the developer, a solvent represented by the following general formula (S2) is also preferred.

[0119] R''-C(=O)-O-R'''-O-R'''' General formula (S2)

[0120] In general formula (S2), R" and R"" each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxyl group, an alkoxycarbonyl group, a carboxyl group, a hydroxyl group, a cyano group, or a halogen atom. R" and R"" may be bonded to each other to form a ring. R'' and R'''' are preferably a hydrogen atom or an alkyl group. The alkyl group, alkoxyl group, and alkoxycarbonyl group represented by R'' and R'''' preferably have 1 to 15 carbon atoms, and the cycloalkyl group preferably has 3 to 15 carbon atoms. R''' represents an alkylene group or a cycloalkylene group, preferably an alkylene group. The alkylene group represented by R''' preferably has 1 to 10 carbon atoms, and the cycloalkylene group represented by R''' preferably has 3 to 10 carbon atoms. The alkylene group represented by R''' may have an ether bond in the alkylene chain. The alkyl group, cycloalkyl group, alkoxyl group, and alkoxycarbonyl group represented by R" and R"", the alkylene group and cycloalkylene group represented by R"", and the ring formed by bonding R" and R"" together may have a substituent. The substituent is not particularly limited, and examples thereof include a hydroxyl group, a group containing a carbonyl group (e.g., an acyl group, an aldehyde group, and an alkoxycarbonyl), and a cyano group.

[0121] Examples of the solvent represented by general formula (S2) include propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methyl-3-methoxypropionate, ethyl-3- Examples of suitable alkoxylated esters include methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, ethyl methoxyacetate, ethyl ethoxyacetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, and 4-methyl-4-methoxypentyl acetate. Among these, propylene glycol monomethyl ether acetate is preferred. Among these, it is preferable that R″ and R′″ are unsubstituted alkyl groups and R′″ is an unsubstituted alkylene group, it is more preferable that R″ and R′″ are either a methyl group or an ethyl group, and it is even more preferable that R″ and R′″ are methyl groups.

[0122] When the developer contains a solvent represented by general formula (S2), the developer may further contain one or more co-used solvents. The co-used solvents are not particularly limited as long as they can be mixed with the solvent represented by general formula (S2) without separation, and examples thereof include solvents selected from the group consisting of ester solvents other than the solvent represented by general formula (S2), ketone solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. The solvent may be one kind or two or more kinds, but it is preferable to use one kind in order to obtain stable performance. When the developer is a mixed solvent of the solvent represented by general formula (S2) and one kind of co-solvent, the mass ratio of the content of the solvent represented by general formula (S2) to the co-solvent [mass content of solvent represented by general formula (S2) / mass content of co-solvent] is usually 20 / 80 to 99 / 1, preferably 50 / 50 to 97 / 3, more preferably 60 / 40 to 95 / 5, and even more preferably 60 / 40 to 90 / 10.

[0123] As the organic solvent used as the developer, an ether solvent containing one or more aromatic rings is also preferred, a solvent represented by the following general formula (S3) is more preferred, and anisole is even more preferred.

[0124] [ka]

[0125] In general formula (S3), R S represents an alkyl group. The alkyl group preferably has 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0126] As the developer (other developer), a water-based alkaline developer may be used.

[0127] (Rinse process) The rinsing step is a step of cleaning (rinsing) with a rinse liquid after the developing step.

[0128] In the rinsing step, the developed substrate is washed using the above-mentioned rinse solution. The cleaning method is not particularly limited, and examples that can be used include a method in which a rinse solution is continuously discharged onto a substrate rotating at a constant speed (rotary discharge method), a method in which a substrate is immersed for a certain period of time in a tank filled with a rinse solution (dip method), and a method in which a rinse solution is sprayed onto the surface of the substrate (spray method). Among these, it is preferable to perform the cleaning method by the rotary discharge method, and then rotate the substrate at a rotation speed of 2000 to 4000 rpm after cleaning to remove the rinse solution from the substrate. The rinsing time is preferably from 10 to 300 seconds, more preferably from 10 to 180 seconds, and even more preferably from 20 to 120 seconds. The temperature of the rinse liquid is preferably 0 to 50°C, more preferably 15 to 35°C.

[0129] As the rinse liquid, the above-mentioned treatment liquid may be used, or other rinse liquids may be used. Other rinsing liquids include, for example, the other developers mentioned above and water.

[0130] After the development process or the rinsing process, the developer or rinsing liquid adhering to the pattern can be removed using a supercritical fluid. Furthermore, after the development treatment, rinsing treatment, or treatment with a supercritical fluid, a drying treatment may be carried out to remove the solvent remaining in the pattern. The drying temperature is preferably 40 to 160°C, more preferably 50 to 150°C, and even more preferably 50 to 110°C. The drying time is preferably from 15 to 300 seconds, more preferably from 15 to 180 seconds.

[0131] In the pattern forming method according to the present invention, the processing liquid of the present invention is used as at least one of the developer and the rinse, and it is particularly preferred that the processing liquid of the present invention is used as the rinse.

[0132] For example, when pattern formation is carried out using an ester-based solvent as the developer in the development step and the treatment liquid of the present invention as the rinse liquid in the rinse step, it is preferable to leave an interval of 1 second or more between the supply of the developer and the rinse liquid to the exposed resist film. By leaving an interval of a predetermined time or more between the supply of the developer and the rinse liquid, deterioration of the solubility of the unexposed regions of the exposed resist film can be suppressed and an increase in defects due to solvent shock can be suppressed.

[0133] In addition, in general, the developer and rinse solution are collected in a common waste solution tank through piping after use. In this case, if an ester-based solvent is used as the developer in the developing step and the treatment solution of the present invention is used as the rinse solution in the rinsing step, the resist dissolved in the developer may precipitate and adhere to the back surface of the substrate, the side surface of the piping, etc., and may contaminate the equipment. To solve the above problem, there is a method of passing the solvent that dissolves the resist through the piping again.The method of passing the solvent through the piping can be exemplified by a method of washing the backside and sides of the substrate with the solvent that dissolves the resist after cleaning with the rinse liquid, or by a method of passing the solvent that dissolves the resist through the piping without contacting the resist. The solvent passed through the pipe is not particularly limited as long as it can dissolve the resist, and examples thereof include the organic solvents used as the developer described above. Specific examples include propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether propionate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-heptanone, ethyl lactate, 1-propanol, and acetone. Among these, PGMEA, PGME, and cyclohexanone are preferred.

[0134] Other methods for solving the above problems include adjusting the ratio of the amounts of the developer and rinse liquid flowing through the pipes after use to a ratio that does not cause resist precipitation in the waste liquid that is flowed through the pipes to a waste liquid tank after use, and mixing a solvent that is highly soluble in resist with the developer and rinse liquid that are flowed through the pipes after use.Specific methods include, for example, continuously supplying an organic solvent that has a higher SP value than the fluorine-containing solvent and / or second solvent contained in the processing liquid of the present invention to the backside of the wafer during the developing step and rinsing step, thereby suppressing resist precipitation and sedimentation in the waste liquid that is flowed through the pipes to a waste liquid tank after use.

[0135] Furthermore, it is also preferable that the developer and rinse liquid are stored in separate waste liquid tanks after use. For example, when pattern formation is performed using an ester-based solvent as the developer in the development step and the treatment liquid of the present invention as the rinse liquid in the rinse step, if the developer and the treatment liquid are collected in a common waste liquid tank through piping after use, components contained in the resist composition, such as resin dissolved in the developer, may precipitate (precipitate and solidify), causing contamination of the equipment. Specifically, the precipitated components may clog the waste liquid piping and contaminate the treatment chamber. To solve the above problem, it is preferable to store the developer and the rinse liquid in separate waste liquid tanks by switching piping or by switching treatment chambers after use. Furthermore, it is preferable to rinse the treatment chamber with a solvent having a higher SP value than the fluorine-based solvent contained in the treatment liquid of the present invention after treatment in order to remove resist components that may adhere to the treatment chamber.

[0136] [Resist Composition] Next, the resist composition to be used in combination with the treatment liquid of the present invention may be, for example, a so-called chemically amplified resist composition containing a resin, a photoacid generator, and / or an acid diffusion controller, or a molecular resist composition containing a low-molecular-weight phenolic compound instead of a resin, or a metal resist composition containing a metal oxide-based compound, or a main-chain scission resist composition in which the polymer main chain is scissed upon exposure to reduce the molecular weight. The resist composition may be a negative resist composition or a positive resist composition. A chemically amplified resist composition, which is one type of resist composition that can be used in combination with the treatment liquid of the present invention, will be described in detail below. In the following description, the chemically amplified resist composition may be simply referred to as the resist composition.

[0137] <Resin (A)> The resist composition contains a resin that decomposes under the action of an acid to increase its polarity (hereinafter, also referred to as an "acid-decomposable resin" or "resin (A)"). That is, in the pattern formation method, typically, when an alkaline developer is used as the developer, a positive pattern is preferably formed, and when an organic developer is used as the developer, a negative pattern is preferably formed. The resin (A) generally contains a group that decomposes under the action of an acid to increase its polarity (hereinafter also referred to as an "acid-decomposable group"), and preferably contains a repeating unit having an acid-decomposable group.

[0138] <Repeating unit having an acid-decomposable group> 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 that decomposes under the action of an acid to generate a polar group. The polarity of a resin having this repeating unit increases under the action of an acid, increasing its solubility in alkaline developers and decreasing its solubility in organic solvents. 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 phosphate 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 alcoholic hydroxyl groups. Of 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.

[0139] Examples of the leaving group that is eliminated by the action of an acid include groups represented by 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)

[0140] 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 groups of Rx1 to Rx3 are preferably alkyl groups having 1 to 5 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 groups of Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and 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 ring formed by combining two of Rx1 to Rx3 is preferably a cycloalkyl 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, a group having a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. In the group represented by formula (Y1) or formula (Y2), 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.

[0141] In formula (Y3), R 36 ~R 38 R each independently represents a hydrogen atom or a monovalent organic group. 37 and R 38 may be bonded to each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. R 36 is also preferably a hydrogen atom. The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom and / or a group having a heteroatom such as a carbonyl group. For example, the alkyl group, cycloalkyl group, aryl group, and aralkyl group may have one or more methylene groups replaced with a heteroatom such as an oxygen atom and / or a group having a heteroatom such as a carbonyl group. Also, R 38 may bond with another substituent on the main chain of the repeating unit to form a ring. 38The group formed by bonding together the repeating unit and another substituent carried by the main chain of the repeating unit is preferably an alkylene group such as a methylene group.

[0142] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0143] [ka]

[0144] Here, L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group combining these (for example, a group combining an alkyl group and an aryl group). M represents a single bond or a divalent linking group. Q represents an alkyl group which may contain a heteroatom, a cycloalkyl group which may contain a heteroatom, an aryl group which may contain a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group combining these (for example, a group combining an alkyl group and a cycloalkyl group). In the alkyl group and cycloalkyl group, for example, one of the methylene groups may be replaced with a heteroatom such as an oxygen atom or a group having a heteroatom such as a carbonyl group. Preferably, one of L1 and L2 is a hydrogen atom, and the other is an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkylene group and an aryl group are combined. 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 pattern miniaturization, L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Examples of secondary alkyl groups include an isopropyl group, a cyclohexyl group, or a norbornyl group, and examples of tertiary alkyl groups include a tert-butyl group or an adamantane group. In these embodiments, Tg (glass transition temperature) and activation energy are increased, thereby ensuring film strength and suppressing fogging.

[0145] 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 preferably an aryl group.

[0146] From the viewpoint of excellent acid decomposition property of the repeating unit, when a non-aromatic ring is directly bonded to the polar group (or a residue thereof) in the leaving group protecting the polar group, it is also preferable that the ring atom in the non-aromatic ring adjacent to the ring atom directly bonded to the polar group (or a residue thereof) does not have a halogen atom such as a fluorine atom as a substituent.

[0147] Other leaving groups that are eliminated by the action of an acid include a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, and a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0148] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (A).

[0149] [ka]

[0150] 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-, hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, etc.), and linking groups in which a plurality of these groups are linked together. Among these, 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 is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0151] 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 is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. The alkyl group may contain a heteroatom other than a halogen atom, such as an oxygen atom.

[0152] 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. Among these, examples of the leaving group include groups represented by formulae (Z1) to (Z4). Formula (Z1):-C(Rx 11 )(Rx12 )(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)

[0153] In formulas (Z1) and (Z2), Rx 11 ~Rx 13 Rx each independently represents an alkyl group (linear or branched) which may have a fluorine atom or an iodine atom, a cycloalkyl group (monocyclic or polycyclic) which may have a fluorine atom or an iodine atom, an alkenyl group (linear or branched) which may have a fluorine atom or an iodine atom, or an aryl group (monocyclic or polycyclic) which may have a fluorine atom or an iodine atom. 11 ~Rx 13 When all of Rx are alkyl groups (linear or branched), 11 ~Rx 13 At least two of these are preferably methyl groups. Rx 11 ~Rx 13 are the same as Rx1 to Rx3 in (Y1) and (Y2) described above, except that they may have a fluorine atom or an iodine atom, and have the same definitions and preferred ranges as the alkyl group, cycloalkyl group, alkenyl group, and aryl group.

[0154] In formula (Z3), R 136 ~R 138 R each independently represents a hydrogen atom or a monovalent organic group 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 organic group 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, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, for example, one of the methylene groups may be replaced with a heteroatom such as an oxygen atom or a group having a heteroatom such as a carbonyl group. Also, R 138 may bond with another substituent on the main chain of the repeating unit to form a ring. In this case, R 138 The group formed by bonding together the repeating unit and another substituent carried by the main chain of the repeating unit is preferably an alkylene group such as a methylene group.

[0155] Formula (Z3) is preferably a group represented by the following formula (Z3-1).

[0156] [ka]

[0157] where L 11 and L 12each 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).

[0158] 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.

[0159] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (AI).

[0160] [ka]

[0161] 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 monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group).

[0162] The alkyl group represented by Xa1, which may have a substituent, is, for example, a methyl group or -CH2-R 11 Examples of such groups include groups represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, 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, with an alkyl group having 3 or less carbon atoms being preferred, and a methyl group being more preferred. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0163] 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, where 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.

[0164] 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 groups of Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, or polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and 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 also preferably a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, etc. Among these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is preferred. 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, a group having a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. In the repeating unit represented by general formula (AI), for example, Rx1 is a methyl group or an ethyl group, and Rx2 and Rx3 are bonded to form the above-mentioned cycloalkyl group.

[0165] 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).The number of carbon atoms in the substituent is preferably 8 or less.

[0166] 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).

[0167] The content of the repeating units having an acid-decomposable group is preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and particularly preferably 30 mol% or more, based on the total repeating units in the resin (A). There is no upper limit, but it is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less.

[0168] Specific examples of repeating units having an acid-decomposable group are shown below, but the present invention is not limited thereto. In the formula, Xa1 represents H, CH3, CF3, or CH2OH, and Rxa and Rxb each represent a linear or branched alkyl group having 1 to 5 carbon atoms.

[0169] [ka]

[0170] [ka]

[0171] [ka]

[0172] [ka]

[0173] [ka]

[0174] The resin (A) may contain repeating units other than the repeating units mentioned above. For example, the resin (A) may contain at least one repeating unit selected from the group consisting of the following Group A and / or at least one repeating unit selected from the group consisting of the following Group B: Group A: A group consisting of the following repeating units (20) to (29). (20) A repeating unit having an acid group, as described below (21) A repeating unit having a fluorine atom or an iodine atom, as described below. (22) A repeating unit having a lactone group, a sultone group, or a carbonate group, as described below. (23) A repeating unit having a photoacid generating group, which will be described later (24) A repeating unit represented by the following general formula (V-1) or the following general formula (V-2) (25) A repeating unit represented by formula (A) described below (26) A repeating unit represented by formula (B) described below (27) A repeating unit represented by formula (C) described below (28) A repeating unit represented by formula (D) described below (29) A repeating unit represented by formula (E) described below Group B: A group consisting of the following repeating units (30) to (32). (30) A repeating unit having at least one group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group, as described below. (31) A repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposition, which will be described later (32) A repeating unit represented by general formula (III) described below, which does not have either a hydroxyl group or a cyano group.

[0175] When the resist composition is used for EUV exposure or electron beam exposure, the resin (A) preferably has at least one repeating unit selected from the group consisting of Group A above. Furthermore, when the resist composition is used for EUV exposure or electron beam exposure, it is also preferable that the resin (A) contains at least one of a fluorine atom and an iodine atom. When the resin (A) contains both a fluorine atom and an iodine atom, the resin (A) may have one repeating unit containing both a fluorine atom and an iodine atom, or the resin (A) may contain both a repeating unit containing a fluorine atom and a repeating unit containing an iodine atom. Furthermore, when the resist composition is used for EUV exposure or electron beam exposure, the resin (A) preferably has a repeating unit having an aromatic group. When the resist composition is used for ArF exposure, the resin (A) preferably contains at least one repeating unit selected from the group consisting of Group B above. Furthermore, when the resist composition is used for ArF exposure, it is preferable that the resin (A) contains neither fluorine atoms nor silicon atoms. Furthermore, when the composition is used for ArF applications, it is preferable that the resin (A) does not have an aromatic group.

[0176] <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 13 or less. The acid group is preferably, for example, a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group. In addition, one or more (preferably one to two) fluorine atoms of the hexafluoroisopropanol group may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). The -C(CF3)(OH)-CF2- thus formed is also preferred as an acid group. In addition, one or more fluorine atoms may be substituted with a group other than a fluorine atom to form a ring containing -C(CF3)(OH)-CF2-. The repeating unit having an acid group is preferably a repeating unit different from the repeating unit having a structure in which a polar group is protected with a leaving group that is released by the action of an acid, and a repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later.

[0177] The repeating unit having an acid group may have a fluorine atom or an iodine atom.

[0178] The repeating unit having an acid group is preferably a repeating unit represented by formula (B).

[0179] [ka]

[0180] R3 represents a hydrogen atom or a monovalent organic group which may have a fluorine atom or an iodine atom. The monovalent organic group optionally having 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 optionally having a fluorine atom or an iodine atom, a cycloalkyl group optionally having a fluorine atom or an iodine atom, an aryl group optionally having a fluorine atom or an iodine atom, or a group formed by combining these.

[0181] 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.

[0182] L2 represents a single bond or an ester group. L3 represents an (n+m+1)-valent aromatic hydrocarbon ring group or an (n+m+1)-valent alicyclic hydrocarbon ring group. Examples of the aromatic hydrocarbon ring group include a benzene ring group and a naphthalene ring group. The alicyclic hydrocarbon ring group may be monocyclic or polycyclic, and examples thereof include cycloalkyl ring groups. R6 represents a hydroxyl group or a fluorinated alcohol group (preferably a hexafluoroisopropanol group). When R6 is a hydroxyl group, L3 is preferably an (n+m+1)-valent aromatic hydrocarbon ring group. R7 represents a halogen atom, such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. m represents an integer of 1 or more, 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. It is preferable that (n+m+1) is an integer of 1 to 5.

[0183] The repeating unit having an acid group is also preferably a repeating unit represented by the following general formula (I).

[0184] [ka]

[0185] 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 combines with the group to form a ring, it represents an (n+2)-valent aromatic ring group. n represents an integer of 1 to 5.

[0186] R in general formula (I) 41 , R42 , and R 43 The alkyl group is preferably an alkyl group having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, or a dodecyl group, more preferably an alkyl group having 8 or less carbon atoms, and even more preferably an alkyl group having 3 or less carbon atoms.

[0187] R in general formula (I) 41 , R 42 , and R 43 The cycloalkyl group may be monocyclic or polycyclic, and among these, monocyclic cycloalkyl groups having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group, are preferred. R in general formula (I) 41 , R 42 , and R 43 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. 41 , R 42 , and R 43 The alkyl group contained in the alkoxycarbonyl group of the above R 41 , R 42 , and R 43 The same alkyl groups as those in the above are preferred.

[0188] Preferred examples of the substituent in each of the above groups include an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, a urethane group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group, a thioether group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a cyano group, and a nitro group. The number of carbon atoms in the substituent is preferably 8 or less.

[0189] Ar4 represents an (n+1)-valent aromatic ring group. When n is 1, the divalent aromatic ring group 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 a divalent 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. The aromatic ring group may have a substituent.

[0190] Specific examples of the (n+1)-valent aromatic ring group when n is an integer of 2 or greater include groups obtained by removing any (n-1) hydrogen atoms from the above-mentioned specific examples of the divalent aromatic ring group. The (n+1)-valent aromatic ring group may further have a substituent.

[0191] Examples of the substituent that the alkyl group, cycloalkyl group, alkoxycarbonyl group, alkylene group, and (n+1)-valent aromatic ring group may have include, for example, R 41 , R 42 , and R 43 Examples of the alkyl group include the alkyl groups listed above, alkoxy groups such as methoxy, ethoxy, hydroxyethoxy, propoxy, hydroxypropoxy, and butoxy groups; and aryl groups such as phenyl groups. -CONR represented by X4 64 -(R 64 represents a hydrogen atom or an alkyl group) 64 Examples of the alkyl group include alkyl groups having 20 or less carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, hexyl, 2-ethylhexyl, octyl, and dodecyl groups, and alkyl groups having 8 or less carbon atoms are preferred. X4 is preferably a single bond, -COO- or -CONH-, more preferably a single bond or -COO-.

[0192] 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, more preferably a benzene ring group, a naphthalene ring group, or a biphenylene ring group. The repeating unit represented by general formula (I) preferably has a hydroxystyrene structure, and Ar4 is preferably a benzene ring group.

[0193] The repeating unit represented by general formula (1) is preferably a repeating unit represented by the following general formula (1).

[0194] [ka]

[0195] 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 combine with each other to form a ring. R is preferably a hydrogen atom. a represents an integer of 1 to 3. b represents an integer of 0 to (5-a).

[0196] In particular, the resin contained in the resist composition preferably has a hydroxystyrene-based repeating unit. An example of a hydroxystyrene repeating unit is a repeating unit in which A represents a hydrogen atom in the above general formula (1).

[0197] Examples of repeating units having an acid group are shown below: wherein a represents 1 or 2.

[0198] [ka]

[0199] [ka]

[0200] [ka]

[0201] Among the above repeating units, the repeating units specifically described below are preferred: In the formula, R represents a hydrogen atom or a methyl group, and a represents 2 or 3.

[0202] [ka]

[0203] [ka]

[0204] The content of repeating units having an acid group (preferably hydroxystyrene repeating units) is preferably 5 mol% or more, and more preferably 10 mol% or more, based on the total repeating units in the resin (A). There is no particular upper limit, but it is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less.

[0205] <Repeating unit having a fluorine atom or an iodine atom> The resin (A) may have a repeating unit having a fluorine atom or an iodine atom in addition to the above-mentioned repeating unit having an acid-decomposable group and repeating unit having an acid group. The repeating unit having a fluorine atom or an iodine atom is preferably different from other types of repeating units belonging to Group A, such as the repeating unit having a lactone group, a sultone group, or a carbonate group and the repeating unit having a photoacid-generating group, which will be described later.

[0206] The repeating unit having a fluorine atom or an iodine atom is preferably a repeating unit represented by formula (C).

[0207] [ka]

[0208] L5 represents a single bond or an ester group. R9 represents a hydrogen atom or an alkyl group which may have a fluorine atom or an iodine atom. R 10 represents a hydrogen atom, 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 formed by combining these.

[0209] Examples of repeating units having a fluorine atom or an iodine atom are shown below.

[0210] [ka]

[0211] The content of repeating units having fluorine atoms or iodine atoms is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on the total repeating units in the resin (A), and the upper limit is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less. As described above, the repeating units having a fluorine atom or an iodine atom do not include <<repeating units having an acid-decomposable group>> and <<repeating units having an acid group>>. Therefore, the content of the repeating units having a fluorine atom or an iodine atom also refers to the content of repeating units having a fluorine atom or an iodine atom excluding <<repeating units having an acid-decomposable group>> and <<repeating units having an acid group>>.

[0212] The total content of repeating units containing at least one of a fluorine atom and an iodine atom in the repeating units of the resin (A) is preferably 20 mol% or more, more preferably 30 mol% or more, and even more preferably 40 mol% or more, based on the total repeating units of the resin (A). There is no particular upper limit, but it is, for example, 100 mol% or less. Examples of the repeating unit containing at least one of a fluorine atom and an iodine atom include a repeating unit having a fluorine atom or an iodine atom and an acid-decomposable group, a repeating unit having a fluorine atom or an iodine atom and an acid group, and a repeating unit having a fluorine atom or an iodine atom.

[0213] <Repeating unit having a lactone group, a sultone group, or a carbonate group> The resin (A) may have a repeating unit having at least one selected from the group consisting of a lactone group, a sultone group, and a carbonate group (hereinafter, also collectively referred to as a "repeating unit having a lactone group, a sultone group, or a carbonate group"). It is also preferred that the repeating unit having a lactone group, a sultone group, or a carbonate group does not have an acid group such as a hexafluoropropanol group.

[0214] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or the sultone structure is preferably a 5- to 7-membered cyclic lactone structure or a 5- to 7-membered cyclic sultone structure. Among these, a 5- to 7-membered cyclic lactone structure to which another ring structure is fused in the form of a bicyclo structure or a spiro structure, or a 5- to 7-membered cyclic sultone structure to which another ring structure is fused in the form of a bicyclo structure or a spiro structure, is more preferred. Resin (A) preferably has a repeating unit having a lactone structure represented by any one of the following general formulas (LC1-1) to (LC1-21), or a lactone group or sultone group formed by abstracting one or more hydrogen atoms from a ring member atom of a sultone structure represented by any one of the following general formulas (SL1-1) to (SL1-3). Furthermore, the lactone group or sultone group may be directly bonded to the main chain, for example, the ring atoms of the lactone group or sultone group may constitute the main chain of the resin (A).

[0215] [ka]

[0216] The lactone structure or sultone structure portion may have a substituent (Rb2). Preferred examples of the substituent (Rb2) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a hydroxyl group, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or greater, multiple Rb2s may be different from each other, or multiple Rb2s may be bonded to form a ring.

[0217] Examples of repeating units having a group having a lactone structure represented by any of general formulas (LC1-1) to (LC1-21) or a sultone structure represented by any of general formulas (SL1-1) to (SL1-3) include repeating units represented by the following general formula (AI):

[0218] [ka]

[0219] In general formula (AI), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group of Rb0 may have include a hydroxyl group and a halogen atom. Examples of the halogen atom of Rb0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb0 is preferably a hydrogen atom or a methyl group. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group combining these. Among these, a single bond or a linking group represented by -Ab1-CO2- is preferred. Ab1 represents a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, and is preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group. V represents a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any of the general formulae (LC1-1) to (LC1-21), or a group obtained by removing one hydrogen atom from a ring member atom of a sultone structure represented by any of the general formulae (SL1-1) to (SL1-3).

[0220] When optical isomers exist in the repeating unit having a lactone group or a sultone group, any optical isomer may be used. Furthermore, one optical isomer may be used alone, or multiple optical isomers may be used in combination. When one optical isomer is primarily used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

[0221] The carbonate group is preferably a cyclic carbonate ester group. The repeating unit having a cyclic carbonate group is preferably a repeating unit represented by the following general formula (A-1).

[0222] [ka]

[0223] In general formula (A-1), R A 1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group). n represents an integer of 0 or greater. R A 2 represents a substituent. When n is 2 or more, multiple R A 2 may be the same or different. A represents a single bond or a divalent linking group. The divalent linking group is preferably an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group formed by combining these groups. Z represents an atomic group which forms a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula.

[0224] Examples of repeating units having a lactone group, a sultone group, or a carbonate group are shown below.

[0225] [ka]

[0226] [ka]

[0227] [ka]

[0228] The content of repeating units having a lactone group, a sultone group, or a carbonate group is preferably 1 mol% or more, more preferably 5 mol% or more, based on the total repeating units in the resin (A). There is no upper limit, but it is preferably 65 mol% or less, more preferably 30 mol% or less, even more preferably 25 mol% or less, and particularly preferably 20 mol% or less.

[0229] <Repeating unit having a photoacid-generating group> The resin (A) may contain, as a repeating unit other than those mentioned above, a repeating unit having a group that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as a "photoacid-generating group"). In this case, the repeating unit having this photoacid generating group can be considered to be a compound that generates an acid when irradiated with actinic rays or radiation (hereinafter also referred to as a "photoacid generator") as described below. An example of such a repeating unit is a repeating unit represented by the following general formula (4).

[0230] [ka]

[0231] R 41 represents a hydrogen atom or a methyl group. 41 represents a single bond or a divalent linking group. 42 represents a divalent linking group. 40 represents a structural moiety that is decomposed by irradiation with actinic rays or radiation to generate an acid in the side chain.

[0232] Examples of repeating units having a photoacid generating group are shown below.

[0233] [ka]

[0234] [ka]

[0235] Other examples of the repeating unit represented by general formula (4) include the repeating units described in paragraphs

[0094] to

[0105] of JP-A No. 2014-041327.

[0236] The content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 5 mol% or more, based on the total repeating units in the resin (A), and the upper limit is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less.

[0237] <Repeating unit represented by general formula (V-1) or the following general formula (V-2)> The resin (A) may have a repeating unit represented by the following general formula (V-1) or the following general formula (V-2). The repeating units represented by the following general formula (V-1) and the following general formula (V-2) are preferably repeating units different from the repeating units described above.

[0238] [ka]

[0239] During the ceremony, R6 and R7 each independently represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. The alkyl group is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. n3 represents an integer of 0 to 6. n4 represents an integer of 0 to 4. X 4 is a methylene group, an oxygen atom, or a sulfur atom. Examples of the repeating unit represented by formula (V-1) or (V-2) are shown below.

[0240] [ka]

[0241] <Repeating units for reducing main chain mobility> Resin (A) preferably has a high glass transition temperature (Tg) from the viewpoint of suppressing excessive diffusion of generated acid or pattern collapse during development. Tg is preferably higher than 90°C, more preferably higher than 100°C, even more preferably higher than 110°C, and particularly preferably higher than 125°C. Note that an excessively high Tg leads to a decrease in the dissolution rate in a developer, so Tg is preferably 400°C or lower, more preferably 350°C or lower. In this specification, the glass transition temperature (Tg) of a polymer such as resin (A) is calculated by the following method. First, the Tg of each homopolymer consisting of only each repeating unit contained in the polymer is calculated using the Bicerano method. Hereinafter, the calculated Tg is referred to as the "Tg of the repeating unit." Next, the mass proportion (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg for each mass proportion is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and these are summed to obtain the Tg (°C) of the polymer. The Bicerano method is described in, for example, Prediction of Polymer Properties, Marcel Dekker Inc., New York (1993). Calculation of Tg by the Bicerano method can be performed using polymer property estimation software MDL Polymer (MDL Information Systems, Inc.).

[0242] In order to increase the Tg of the resin (A) (preferably to make the Tg exceed 90°C), it is preferable to reduce the mobility of the main chain of the resin (A). Methods for reducing the mobility of the main chain of the resin (A) include the following methods (a) to (e). (a) Introduction of bulky substituents into the main chain (b) Introduction of multiple substituents into the main chain (c) Introduction of a substituent group that induces interactions between resins (A) near the main chain (d) Main chain formation in a cyclic structure (e) Linking of cyclic structures to the main chain The resin (A) preferably has a repeating unit that exhibits a homopolymer Tg of 130° C. or higher. The repeating units exhibiting a homopolymer Tg of 130° C. or higher are not particularly limited as long as they are repeating units exhibiting a homopolymer Tg of 130° C. or higher as calculated by the Bicerano method. Depending on the type of functional group in the repeating units represented by formulas (A) to (E) described below, they may be considered as repeating units exhibiting a homopolymer Tg of 130° C. or higher.

[0243] (Repeating unit represented by formula (A)) One example of a specific means for achieving the above (a) is to introduce a repeating unit represented by formula (A) into resin (A).

[0244] [ka]

[0245] Formula (A), R A represents a group having a polycyclic structure. x represents a hydrogen atom, a methyl group, or an ethyl group. The group having a polycyclic structure is a group having a plurality of ring structures, and the plurality of ring structures may or may not be condensed. Specific examples of the repeating unit represented by formula (A) include the following repeating units.

[0246] [ka]

[0247] [ka]

[0248] [ka]

[0249] In the above formula, R represents a hydrogen atom, a methyl group, or an ethyl group. Ra represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR''' or -COOR''': R''' represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. Furthermore, a hydrogen atom bonded to a carbon atom in the group represented by Ra may be substituted with a fluorine atom or an iodine atom. R' and R" each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR'" or -COOR''': R'" represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. A hydrogen atom bonded to a carbon atom in the group represented by R' and R" may be substituted with a fluorine atom or an iodine atom. L represents a single bond or a divalent linking group. Examples of the divalent linking group include —COO—, —CO—, —O—, —S—, —SO—, —SO2-, an alkylene group, a cycloalkylene group, an alkenylene group, and linking groups in which a plurality of these groups are linked together. m and n each independently represent an integer of equal to or greater than 0. There are no particular upper limits for m and n, but they are often 2 or less, and more often 1 or less.

[0250] (Repeating unit represented by formula (B)) One example of a specific means for achieving the above (b) is a method of introducing a repeating unit represented by formula (B) into resin (A).

[0251] [ka]

[0252] In formula (B), R b1 ~R b4 each independently represents a hydrogen atom or an organic group, R b1 ~R b4 At least two of these represent organic groups. In addition, when at least one of the organic groups is a group in which a ring structure is directly linked to the main chain in the repeating unit, the types of the other organic groups are not particularly limited. Furthermore, when none of the organic groups has a ring structure directly linked to the main chain in the repeating unit, at least two of the organic groups are substituents having three or more constituent atoms excluding hydrogen atoms.

[0253] Specific examples of the repeating unit represented by formula (B) include the following repeating units.

[0254] [ka]

[0255] In the above formula, each R independently represents a hydrogen atom or an organic group, such as an optionally substituted alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. Each R' independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR" or -COOR: R" is an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. Furthermore, a hydrogen atom bonded to a carbon atom in the group represented by R' may be substituted with a fluorine atom or an iodine atom. m represents an integer of 0 or greater. There is no particular upper limit to m, but it is often 2 or less, and more often 1 or less.

[0256] (Repeating unit represented by formula (C)) One example of a specific means for achieving the above (c) is to introduce a repeating unit represented by formula (C) into resin (A).

[0257] [ka]

[0258] In formula (C), R c1 ~R c4 each independently represents a hydrogen atom or an organic group, R c1 ~R c4 At least one of the groups has a hydrogen-bonding hydrogen atom within three atoms from the main chain carbon. In particular, in order to induce interaction between the main chains of the resin (A), it is preferable to have a hydrogen-bonding hydrogen atom within two atoms (closer to the main chain).

[0259] Specific examples of the repeating unit represented by formula (C) include the following repeating units.

[0260] [ka]

[0261] In the above formula, R represents an organic group, which may have a substituent, such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, or an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms). R' represents a hydrogen atom or an organic group. Examples of the organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. The hydrogen atom in the organic group may be substituted with a fluorine atom or an iodine atom.

[0262] (Repeating unit represented by formula (D)) One example of a specific means for achieving the above (d) is to introduce a repeating unit represented by formula (D) into resin (A).

[0263] [ka]

[0264] In formula (D), "cylic" represents a group that forms a main chain with a cyclic structure. The number of atoms constituting the ring is not particularly limited.

[0265] Specific examples of the repeating unit represented by formula (D) include the following repeating units.

[0266] [ka]

[0267] In the above formula, each R independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR" or -COOR: R" represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. Furthermore, a hydrogen atom bonded to a carbon atom in the group represented by R may be substituted with a fluorine atom or an iodine atom. In the above formula, each R' independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR" or -COOR): R" represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. Furthermore, a hydrogen atom bonded to a carbon atom in the group represented by R' may be substituted with a fluorine atom or an iodine atom. m represents an integer of 0 or greater. There is no particular upper limit to m, but it is often 2 or less, and more often 1 or less.

[0268] (Repeating unit represented by formula (E)) One example of a specific means for achieving the above (e) is to introduce a repeating unit represented by formula (E) into resin (A).

[0269] [ka]

[0270] In formula (E), each Re independently represents a hydrogen atom or an organic group, such as an optionally substituted alkyl group, cycloalkyl group, aryl group, aralkyl group, or alkenyl group. "Cylic" refers to a cyclic group containing carbon atoms in the main chain. There are no particular restrictions on the number of atoms contained in the cyclic group.

[0271] Specific examples of the repeating unit represented by formula (E) include the following repeating units.

[0272] [ka]

[0273] [ka]

[0274] In the above formula, each R independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR" or -COOR: R" represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. Furthermore, a hydrogen atom bonded to a carbon atom in the group represented by R may be substituted with a fluorine atom or an iodine atom. R' each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR" or -COOR: R" represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group may each have a substituent. Furthermore, a hydrogen atom bonded to a carbon atom in the group represented by R' may be substituted with a fluorine atom or an iodine atom. m represents an integer of 0 or greater. There is no particular upper limit to m, but it is often 2 or less, and more often 1 or less. In addition, in formula (E-2), formula (E-4), formula (E-6), and formula (E-8), two Rs may be bonded to each other to form a ring.

[0275] The content of the repeating unit represented by formula (E) is preferably 5 mol % or more, more preferably 10 mol % or more, based on the total repeating units in the resin (A), and the upper limit is preferably 60 mol % or less, more preferably 55 mol % or less.

[0276] <<Repeating Unit Having at Least One Group Selected from a Lactone Group, a Sultone Group, a Carbonate Group, a Hydroxyl Group, a Cyano Group, and an Alkali-Soluble Group>> The resin (A) may have a repeating unit having at least one type of group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group. Examples of the repeating unit having a lactone group, a sultone group, or a carbonate group contained in the resin (A) include the repeating units described above in <<Repeating Units Having a Lactone Group, a Sultone Group, or a Carbonate Group>>. The preferred content is also as described above in <<Repeating Units Having a Lactone Group, a Sultone Group, or a Carbonate Group>>.

[0277] The resin (A) may contain a repeating unit having a hydroxyl group or a cyano group, which improves the adhesion to the substrate and the affinity for the developer. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The repeating unit having a hydroxyl group or a cyano group preferably does not have an acid-decomposable group. Examples of the repeating unit having a hydroxyl group or a cyano group include repeating units represented by the following general formulae (AIIa) to (AIId).

[0278] [ka]

[0279] In general formulae (AIIa) to (AIId), R 1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. R 2c ~R 4c each independently represents a hydrogen atom, a hydroxyl group, or a cyano group. 2c ~R 4c At least one of R represents a hydroxyl group or a cyano group. 2c ~R 4c Among these, one or two are hydroxyl groups and the rest are hydrogen atoms. More preferably, R 2c ~R 4c Of these, two are hydroxyl groups and the rest are hydrogen atoms.

[0280] The content of repeating units having a hydroxyl group or a cyano group is preferably 5 mol% or more, more preferably 10 mol% or more, based on the total repeating units in the resin (A), and the upper limit is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less.

[0281] Specific examples of repeating units having a hydroxyl group or a cyano group are listed below, but the present invention is not limited to these.

[0282] [ka]

[0283] 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 (e.g., a hexafluoroisopropanol group) substituted at the α-position with an electron-withdrawing group, with a carboxyl group being preferred. When the resin (A) contains a repeating unit having an alkali-soluble group, the resolution in contact hole applications is improved. Examples of repeating units having an alkali-soluble group include repeating units in which the alkali-soluble group is directly bonded to the main chain of the resin, such as repeating units based on acrylic acid and methacrylic acid, and repeating units in which the alkali-soluble group is bonded to the main chain of the resin via a linking group, which may have a monocyclic or polycyclic hydrocarbon structure. The repeating unit having an alkali-soluble group is preferably a repeating unit derived from acrylic acid or methacrylic acid.

[0284] The content of the repeating unit having an alkali-soluble group is preferably 0 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, based on the total repeating units in the resin (A).The upper limit is preferably 20 mol% or less, more preferably 15 mol% or less, and even more preferably 10 mol% or less.

[0285] Specific examples of repeating units having an alkali-soluble group are shown below, but the present invention is not limited thereto: In the specific examples, Rx represents H, CH3, CH2OH, or CF3.

[0286] [ka]

[0287] As a repeating unit having at least one type of group selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group, a repeating unit having at least two selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group is preferred, a repeating unit having a cyano group and a lactone group is more preferred, and a repeating unit having a structure in which a cyano group is substituted on a lactone structure represented by general formula (LC1-4) is even more preferred.

[0288] <Repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposition> Resin (A) may have an alicyclic hydrocarbon structure and a repeating unit that does not exhibit acid decomposition. This reduces the elution of low-molecular-weight components from the resist film into the immersion liquid during immersion exposure. Examples of such repeating units include repeating units derived from 1-adamantyl(meth)acrylate, diamantyl(meth)acrylate, tricyclodecanyl(meth)acrylate, and cyclohexyl(meth)acrylate.

[0289] <Repeating unit represented by general formula (III) having neither a hydroxyl group nor a cyano group> The resin (A) may have a repeating unit represented by general formula (III) that does not have either a hydroxyl group or a cyano group.

[0290] [ka]

[0291] In general formula (III), R5 represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group. Ra represents a hydrogen atom, an alkyl group, or a -CH2-O-Ra2 group, where Ra2 represents a hydrogen atom, an alkyl group, or an acyl group.

[0292] The cyclic structure of R5 includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include a cycloalkyl group having 3 to 12 carbon atoms (more preferably 3 to 7 carbon atoms) and a cycloalkenyl group having 3 to 12 carbon atoms.

[0293] Polycyclic hydrocarbon groups include ring-assembled hydrocarbon groups and bridged cyclic hydrocarbon groups. Examples of the bridged cyclic hydrocarbon ring include a bicyclic hydrocarbon ring, a tricyclic hydrocarbon ring, and a tetracyclic hydrocarbon ring, etc. The bridged cyclic hydrocarbon ring also includes a fused ring in which multiple 5- to 8-membered cycloalkane rings are fused. The bridged cyclic hydrocarbon group may be a norbornyl group, an adamantyl group, a bicyclooctanyl group, or a tricyclo[5,2,1,0 2,6 ]decanyl group is preferred, and norbornyl or adamantyl group is more preferred.

[0294] The alicyclic hydrocarbon group may have a substituent, and examples of the substituent include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, and an amino group protected with a protecting group. The halogen atom is preferably a bromine atom, a chlorine atom, or a fluorine atom. The alkyl group is preferably a methyl group, an ethyl group, a butyl group, or a t-butyl group. The alkyl group may further have a substituent, and the substituent may be a halogen atom, an alkyl group, a hydroxyl group protected by a protecting group, or an amino group protected by a protecting group.

[0295] Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms. The substituted methyl group is preferably a methoxymethyl group, a methoxythiomethyl group, a benzyloxymethyl group, a t-butoxymethyl group, or a 2-methoxyethoxymethyl group. The substituted ethyl group is preferably a 1-ethoxyethyl group or a 1-methyl-1-methoxyethyl group. The acyl group is preferably an aliphatic acyl group having 1 to 6 carbon atoms, such as a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, or a pivaloyl group. The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 1 to 4 carbon atoms.

[0296] The content of repeating units represented by general formula (III) which have neither a hydroxyl group nor a cyano group is preferably from 0 to 40 mol %, more preferably from 0 to 20 mol %, based on all repeating units in the resin (A). Specific examples of the repeating unit represented by general formula (III) are listed below, but the present invention is not limited to these: In the formula, Ra represents H, CH3, CH2OH, or CF3.

[0297] [ka]

[0298] <Other repeating units> Furthermore, the resin (A) may have a repeating unit other than the repeating units described above. For example, the resin (A) may have a repeating unit selected from the group consisting of a repeating unit having an oxathiane ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantoin ring group. Examples of such repeating units are shown below.

[0299] [ka]

[0300] 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.

[0301] It is also preferable that all of the repeating units of the resin (A) are (meth)acrylate repeating units (especially when the composition is used for ArF applications). In this case, any of the repeating units in which all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are a mixture of methacrylate repeating units and acrylate repeating units can be used, and it is preferable that the acrylate repeating units account for 50 mol % or less of all the repeating units.

[0302] The resin (A) can be synthesized by a conventional method (for example, radical polymerization). The weight-average molecular weight of the resin (A), as calculated as polystyrene by the GPC method, is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 5,000 to 15,000. By adjusting the weight-average molecular weight of the resin (A) to 1,000 to 200,000, deterioration in heat resistance and dry etching resistance can be further suppressed. In addition, deterioration in developability and deterioration in film-formability due to increased viscosity can be further suppressed. The polydispersity (molecular weight distribution) of the resin (A) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The smaller the polydispersity, the better the resolution and resist shape, and the smoother the sidewalls of the resist pattern.

[0303] 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 composition. The solid content refers to the components in the composition excluding the solvent, and any components other than the solvent are considered to be solids even if they are liquid components. The resin (A) may be used alone or in combination of two or more.

[0304] <Compounds that generate acid when exposed to actinic rays or radiation (photoacid generators)> The chemically amplified resist composition preferably contains a compound that generates an acid when exposed to actinic rays or radiation (hereinafter also referred to as a "photo acid generator (PAG)"). The photoacid generator may be in the form of a low molecular weight compound, or may be incorporated into a part of a polymer, or may be in the form of a low molecular weight compound and a form of being incorporated into a part of a polymer in combination. When the photoacid generator is in the form of a low molecular weight compound, the molecular weight of the photoacid generator is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less. When the photoacid generator 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 is preferably in the form of a low molecular weight compound. The photoacid generator is not particularly limited as long as it is a known compound, but is preferably a compound that generates an organic acid, such as at least one of sulfonic acid, bis(alkylsulfonyl)imide, and tris(alkylsulfonyl)methide, upon irradiation with actinic rays or radiation, preferably electron beams or extreme ultraviolet rays. More preferred are compounds represented by the following general formula (ZI), (ZII), and (ZIII).

[0305] [ka]

[0306] In the above general formula (ZI), R 201 , R 202、 and R 203 each independently represents an organic group. R 201 , R 202 , and R 203 The organic group as the aryl group preferably has 1 to 30 carbon atoms, and more preferably has 1 to 20 carbon atoms. Also, R 201 ~R 203Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. 201 ~R 203 Among these, examples of groups formed by combining two of them include alkylene groups (for example, butylene and pentylene groups). Z - represents a non-nucleophilic anion (an anion with a significantly reduced ability to undergo nucleophilic reactions).

[0307] Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0308] The aliphatic moiety in the aliphatic sulfonate anion and the aliphatic carboxylate anion may be an alkyl group or a cycloalkyl group, and preferred examples include linear or branched alkyl groups having 1 to 30 carbon atoms and cycloalkyl groups having 3 to 30 carbon atoms.

[0309] The aromatic group in the aromatic sulfonate anion and aromatic carboxylate anion is preferably an aryl group having a carbon number of 6 to 14. Examples include a phenyl group, a tolyl group, and a naphthyl group.

[0310] The alkyl group, cycloalkyl group, and aryl group may have a substituent. Specific examples include a nitro group, a halogen atom such as a fluorine atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms), an acyl group (preferably having 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), an alkylsulfonyl group (preferably having 1 to 15 carbon atoms), an alkyliminosulfonyl group (preferably having 1 to 15 carbon atoms), an aryloxysulfonyl group (preferably having 6 to 20 carbon atoms), an alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), a cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), an alkyloxyalkyloxy group (preferably having 5 to 20 carbon atoms), and a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms). The aryl group and ring structure of each group may further include an alkyl group (preferably having 1 to 15 carbon atoms) as a substituent.

[0311] The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 7 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylbutyl group.

[0312] An example of the sulfonylimide anion is a saccharin anion.

[0313] The alkyl group in the bis(alkylsulfonyl)imide anion or tris(alkylsulfonyl)methide anion is preferably an alkyl group having 1 to 5 carbon atoms. Examples of the substituent on these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, an aryloxysulfonyl group, and a cycloalkylaryloxysulfonyl group, and a fluorine atom or an alkyl group substituted with a fluorine atom is preferred. Furthermore, the alkyl groups in the bis(alkylsulfonyl)imide anion may be bonded to each other to form a ring structure, which increases the acid strength.

[0314] Other non-nucleophilic anions include, for example, phosphorus fluorides (e.g., PF6 - ), boron fluorides (e.g., BF4 - ), and antimony fluorides (e.g., SbF6 - ) etc.

[0315] Preferred non-nucleophilic anions include aliphatic sulfonate anions in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, aromatic sulfonate anions substituted with a fluorine atom or a group having a fluorine atom, bis(alkylsulfonyl)imide anions in which an alkyl group is substituted with a fluorine atom, and tris(alkylsulfonyl)methide anions in which an alkyl group is substituted with a fluorine atom. More preferred non-nucleophilic anions include perfluoroaliphatic sulfonate anions (preferably having 4 to 8 carbon atoms) and benzenesulfonate anions having a fluorine atom, and even more preferred are nonafluorobutanesulfonate anions, perfluorooctanesulfonate anions, pentafluorobenzenesulfonate anions, and 3,5-bis(trifluoromethyl)benzenesulfonate anions.

[0316] From the viewpoint of acid strength or sensitivity, the pKa of the generated acid is preferably −1 or less.

[0317] In addition, as a preferred embodiment of the non-nucleophilic anion, an anion represented by the following general formula (AN1) can also be mentioned.

[0318] [ka]

[0319] In the formula, each Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. R 1 and R 2 each independently represents a hydrogen atom, a fluorine atom, or an alkyl group, and when there are a plurality of R 1 and R 2 may be the same or different. L represents a divalent linking group, and when a plurality of L's are present, they may be the same or different. A represents a cyclic organic group. x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

[0320] General formula (AN1) will be explained in more detail. The number of carbon atoms in the alkyl group substituted with a fluorine atom of Xf is preferably 1 to 10, more preferably 1 to 4. Furthermore, the alkyl group substituted with a fluorine atom of Xf is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Specific examples of Xf include a fluorine atom, CF3, C2F5, C3F7, C4F9, CH2CF3, CH2CH2CF3, CH2C2F5, CH2CH2C2F5, CH2C3F7, CH2CH2C3F7, CH2C4F9, and CH2CH2C4F9. Of these, a fluorine atom or CF3 is preferred. It is particularly preferred that both Xf's are fluorine atoms.

[0321] R 1 and R 2The alkyl group in R may have a substituent (preferably a fluorine atom), and preferably has 1 to 4 carbon atoms. 1 and R 2 The alkyl group in R is preferably a perfluoroalkyl group having 1 to 4 carbon atoms. 1 and R 2 Specific examples of the alkyl group having the substituent include CF3, C2F5, C3F7, C4F9, and C5F 11 , C6F 13 , C7F 15 , C8F 17 , CH2CF3, CH2CH2CF3, CH2C2F5, CH2CH2C2F5, CH2C3F7, CH2CH2C3F7, CH2C4F9, and CH2CH2C4F9. Of these, CF3 is preferred. R 1 and R 2 is preferably a fluorine atom or CF3.

[0322] x is preferably 1 to 10, and more preferably 1 to 5. y is preferably 0 to 4, and 0 is more preferable. z is preferably 0 to 5, and more preferably 0 to 3. The divalent linking group for L is not particularly limited, and examples thereof include -COO-, -OCO-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene groups, cycloalkylene groups, alkenylene groups, and linking groups in which multiple of these groups are linked together. Among these, linking groups having a total of 12 or less carbon atoms are preferred. Furthermore, -COO-, -OCO-, -CO-, or -O- are preferred, and -COO- or -OCO- are more preferred.

[0323] In the above general formula (AN1), as a combination of partial structures other than A, SO 3- -CF2-CH2-OCO-, SO 3- -CF2-CHF-CH2-OCO-, SO 3- -CF2-COO-, SO 3- -CF2-CF2-CH2- and SO 3- -CF2-CH(CF3)-OCO- is preferred.

[0324] The cyclic organic group of A is not particularly limited as long as it has a cyclic structure, and examples thereof include an alicyclic group, an aryl group, and a heterocyclic group (including not only those having aromaticity but also those not having aromaticity). The alicyclic group may be monocyclic or polycyclic, and is preferably a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, or a cyclooctyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. Among these, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, are preferred from the viewpoint of suppressing in-film diffusibility in a post-exposure baking step and improving MEEF (mask error enhancement factor). The aryl group includes a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Examples of the heterocyclic group include those derived from a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Among these, those derived from a furan ring, a thiophene ring, or a pyridine ring are preferred.

[0325] Furthermore, examples of the cyclic organic group include lactone structures, and specific examples include lactone structures represented by the following general formulae (LC1-1) to (LC1-17).

[0326] [ka]

[0327] The cyclic organic group may have a substituent, and examples of the substituent include an alkyl group (which may be linear, branched, or cyclic and preferably has 1 to 12 carbon atoms), a cycloalkyl group (which may be monocyclic, polycyclic, or spirocyclic and preferably has 3 to 20 carbon atoms), an aryl group (which preferably has 6 to 14 carbon atoms), a hydroxy group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonate ester group. The carbon constituting the cyclic organic group (the carbon contributing to ring formation) may be a carbonyl carbon. The above substituents correspond to Rb2 in the above general formulae (LC1-1) to (LC1-17). In the above general formulae (LC1-1) to (LC1-17), n2 represents an integer of 0 to 4. When n2 is 2 or greater, multiple Rb2 may be the same or different, and multiple Rb2 may be bonded to form a ring.

[0328] In general formula (ZI), R 201 , R 202 , and R 203 Examples of the organic group include an aryl group, an alkyl group, and a cycloalkyl group. R 201 , R 202 , and R 203 Among these, it is preferable that at least one is an aryl group, and it is more preferable that all three are aryl groups. The aryl group may be a phenyl group, a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue. 201 ~R 203The alkyl group and cycloalkyl group are preferably a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. These groups may further have a substituent. Examples of the further substituent include a nitro group, a halogen atom such as a fluorine atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms), an acyl group (preferably having 2 to 12 carbon atoms), and an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), but are not limited thereto.

[0329] Next, general formulae (ZII) and (ZIII) will be explained. In general formulas (ZII) and (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group, or a cycloalkyl group. R 204 ~R 207 The aryl group in R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. 204 ~R 207 The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, a sulfur atom, etc. Examples of the skeleton of the aryl group having a heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. R 204 ~R 207The alkyl group and cycloalkyl group in the formula (I) are preferably linear or branched alkyl groups having 1 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups).

[0330] R 204 ~R 207 The aryl group, alkyl group, and cycloalkyl group in R may have a substituent. 204 ~R 207 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.

[0331] In addition, in general formula (ZII), Z - represents a non-nucleophilic anion. Specifically, in general formula (ZI), Z - The preferred embodiment is also the same as that described above.

[0332] Specific examples of general formulas (ZI) to (ZIII) are shown below, but the invention is not limited thereto.

[0333] [ka]

[0334] In the present invention, the photoacid generator is a compound that can be used to form a film having a volume of 130 Å by irradiation with an electron beam or extreme ultraviolet light, from the viewpoint of suppressing the diffusion of the acid generated by exposure to the non-exposed area and improving the resolution. 3 A compound that generates an acid (more preferably a sulfonic acid) with a volume of 190 Å or more. 3 It is more preferable that the compound generates an acid (more preferably a sulfonic acid) having a volume of 270 Å or more. 3It is more preferable that the compound is a compound that generates an acid (more preferably a sulfonic acid) having a volume of 400 Å or more. 3 However, from the viewpoint of sensitivity and solubility in a coating solvent, the above volume is preferably 2000 Å or more. 3 Preferably, it is 1500 Å or less. 3 It is even more preferable that the volume is less than 1 / 2 Å. The above volume values ​​were determined using "WinMOPAC" manufactured by Fujitsu Limited. First, the chemical structure of the acid in each example is input, and then the most stable conformation of each acid is determined by molecular force field calculation using the MM3 method using this structure as the initial structure. Then, the "accessible volume" of each acid can be calculated by performing molecular orbital calculations using the PM3 method for these most stable conformations. Note that 1 Å means 0.1 nm. In the present invention, photoacid generators that generate the acids exemplified below upon irradiation with actinic rays or radiation are preferred. Note that some of the examples include calculated values ​​for volume (unit: Å). 3 ) The calculated value here is the volume of the acid with a proton bonded to the anion portion.

[0335] [ka]

[0336] [ka]

[0337] [ka]

[0338] Examples of photoacid generators include those described in paragraphs

[0368] to

[0377] of JP 2014-41328 A and paragraphs

[0240] to

[0262] of JP 2013-228681 A (corresponding paragraphs of U.S. Patent Application Publication No. 2015 / 004533 A).

[0339] ) are incorporated herein by reference, the contents of which are hereby incorporated by reference. Preferred specific examples include, but are not limited to, the following compounds:

[0339] [ka]

[0340] [ka]

[0341] [ka]

[0342] [ka]

[0343] The photoacid generators can be used singly or in combination of two or more. The content of the photoacid generator in the resist composition is preferably 0.1 to 50 mass %, more preferably 5 to 50 mass %, and even more preferably 8 to 40 mass %, based on the total solid content of the composition. In particular, a higher content of the photoacid generator is preferable to achieve both high sensitivity and high resolution during exposure to electron beams or extreme ultraviolet rays. From the above viewpoints, the content is preferably 10 to 40 mass %, and more preferably 10 to 35 mass %.

[0344] <Solvent> A solvent can be used when preparing the resist composition by dissolving the above-mentioned components. Examples of solvents that can be used include organic solvents such as alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cyclic lactones having 4 to 10 carbon atoms, monoketone compounds having 4 to 10 carbon atoms that may contain a ring, alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates.

[0345] Examples of alkylene glycol monoalkyl ether carboxylates include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate. Examples of alkylene glycol monoalkyl ethers include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

[0346] Examples of alkyl lactate esters include methyl lactate, ethyl lactate, propyl lactate, and butyl lactate. Examples of alkyl alkoxypropionates include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate.

[0347] Examples of cyclic lactones having 4 to 10 carbon atoms include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-octanoic lactone, and α-hydroxy-γ-butyrolactone.

[0348] Examples of monoketone compounds having 4 to 10 carbon atoms and which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 2 3-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-hexen-2-one, 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcycloheptanone, and 3-methylcycloheptanone.

[0349] Alkylene carbonates include, for example, propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate. Examples of alkoxy alkyl acetates include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2-(2-ethoxyethoxy)ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-2-propyl acetate. Alkyl pyruvates include, for example, methyl pyruvate, ethyl pyruvate, and propyl pyruvate. Among these, the solvent is preferably one having a boiling point of 130° C. or higher at room temperature and normal pressure. Specific examples include cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, 2-(2-ethoxyethoxy)ethyl acetate, and propylene carbonate.

[0350] The above solvents may be used alone or in combination of two or more.

[0351] In the present invention, the organic solvent may be a mixed solvent obtained by mixing a solvent containing a hydroxyl group in its structure with a solvent not containing a hydroxyl group. Examples of solvents containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and ethyl lactate. Of these, propylene glycol monomethyl ether and ethyl lactate are preferred. Examples of solvents not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N,N-dimethylacetamide, and dimethyl sulfoxide. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and 2-heptanone are more preferred. The mass ratio of the content of the hydroxyl-containing solvent to the hydroxyl-free solvent [mass content of the hydroxyl-containing solvent / mass content of the hydroxyl-free solvent] is preferably 1 / 99 to 99 / 1, more preferably 10 / 90 to 90 / 10, and even more preferably 20 / 80 to 60 / 40. From the viewpoint of coating uniformity, the mass of the hydroxyl-free solvent in the mixed solvent is preferably 50 mass% or more.

[0352] The solvent is preferably a mixed solvent of two or more kinds containing propylene glycol monomethyl ether acetate, and a combination of γ-butyl lactone and butyl acetate is more preferred.

[0353] As the solvent, for example, the solvents described in paragraphs

[0013] to

[0029] of JP-A-2014-219664 can also be used.

[0354] <Acid diffusion control agent> The resist composition preferably contains an acid diffusion controller in order to reduce changes in performance over time from exposure to heating.

[0355] The acid diffusion controller may be, for example, a basic compound. Examples of basic compounds include compounds having structures represented by the following formulae (A1) to (E1).

[0356] [ka]

[0357] R in general formulas (A1) and (E1) 200 , R 201 , and R 202 may be the same or different and represent a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (preferably having 6 to 20 carbon atoms). 201 and R 202 may be bonded to each other to form a ring.

[0358] The alkyl group having the above substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms. R 203 , R 204 , R 205 , and R 206 may be the same or different and represent an alkyl group having 1 to 20 carbon atoms. The alkyl groups in the general formulae (A1) and (E1) are preferably unsubstituted.

[0359] Examples of compounds having a structure represented by general formulas (A1) to (E1) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, as well as compounds having an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure, or a pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, and aniline derivatives having a hydroxyl group and / or an ether bond.

[0360] Compounds having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Compounds having a diazabicyclo structure include 1,4-diazabicyclo[2,2,2]octane, 1,5-diazabicyclo[4,3,0]non-5-ene, and 1,8-diazabicyclo[5,4,0]undec-7-ene. Compounds having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, and sulfonium hydroxides having a 2-oxoalkyl group. Specific examples include triphenylsulfonium hydroxide, tris(t-butylphenyl)sulfonium hydroxide, bis(t-butylphenyl)iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. Compounds having an onium carboxylate structure include compounds having an onium hydroxide structure in which the anion moiety is carboxylate, such as acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Compounds having a trialkylamine structure include tri(n-butyl)amine and tri(n-octyl)amine. Examples of the aniline compound include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline. Examples of alkylamine derivatives having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris(methoxyethoxyethyl)amine. Examples of the aniline derivatives having a hydroxyl group and / or an ether bond include N,N-bis(hydroxyethyl)aniline.

[0361] Further examples of the basic compound include amine compounds having a phenoxy group and ammonium salt compounds having a phenoxy group.

[0362] The amine compound may be a primary, secondary, or tertiary amine compound, and is preferably an amine compound having at least one alkyl group bonded to the nitrogen atom. The amine compound is more preferably a tertiary amine compound. As long as the amine compound has at least one alkyl group (preferably having 1 to 20 carbon atoms) bonded to the nitrogen atom, a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 6 to 12 carbon atoms) may be bonded to the nitrogen atom in addition to the alkyl group. The amine compound preferably has an oxygen atom in the alkyl chain to form an oxyalkylene group. The number of oxyalkylene groups in the molecule is one or more, preferably 3 to 9, and more preferably 4 to 6. Of these, the oxyalkylene group is preferably an oxyethylene group (-CH2CH2O-) or an oxypropylene group (-CH(CH3)CH2O- or -CH2CH2CH2O-), and more preferably an oxyethylene group.

[0363] The ammonium salt compound may be a primary, secondary, tertiary, or quaternary ammonium salt compound, and is preferably an ammonium salt compound having at least one alkyl group bonded to the nitrogen atom. In the ammonium salt compound, as long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to the nitrogen atom, a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 6 to 12 carbon atoms) may be bonded to the nitrogen atom in addition to the alkyl group. The ammonium salt compound preferably has an oxygen atom in the alkyl chain to form an oxyalkylene group. The number of oxyalkylene groups in the molecule is one or more, preferably 3 to 9, and more preferably 4 to 6. Of these, the oxyalkylene group is preferably a (-CH2CHO-) group or an oxypropylene group (-CH(CH3)CHO- or CH2CH2CHO-), and more preferably an oxyethylene group. Examples of anions of ammonium salt compounds include halogen atoms, sulfonates, borates, and phosphates. Among these, halogen atoms or sulfonates are preferred. Examples of halogen atoms include chloride, bromide, and iodide. Examples of sulfonates include organic sulfonates having 1 to 20 carbon atoms. Examples of organic sulfonates include alkyl sulfonates and aryl sulfonates having 1 to 20 carbon atoms. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, an alkoxy group, an acyl group, and an aryl group. Examples of alkyl sulfonates include methanesulfonate, ethanesulfonate, butanesulfonate, hexanesulfonate, octane sulfonate, benzyl sulfonate, trifluoromethanesulfonate, pentafluoroethanesulfonate, and nonafluorobutanesulfonate. Examples of aryl groups of aryl sulfonates include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, naphthalene ring, and anthracene ring may have a substituent, and the substituent is preferably a linear or branched alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the linear or branched alkyl group and the cycloalkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-hexyl group, and a cyclohexyl group. Other examples of the substituent include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a nitro group, an acyl group, and an acyloxy group.

[0364] An amine compound having a phenoxy group or an ammonium salt compound having a phenoxy group is an amine compound or an ammonium salt compound having a phenoxy group at the end opposite to the nitrogen atom of the alkyl group of the amine compound or the ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. The substitution position of the substituent may be any of the 2nd to 6th positions. The number of substituents may be any within the range of 1 to 5.

[0365] It is preferable that at least one oxyalkylene group is present between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups in the molecule is one or more, preferably 3 to 9, and more preferably 4 to 6. Of these, the oxyalkylene group is preferably an oxyethylene group (-CH2CHO-) or an oxypropylene group (-CH(CH3)CHO- or -CH2CH2CHO-), and more preferably an oxyethylene group.

[0366] A phenoxy group-containing amine compound can be obtained by heating a primary or secondary amine having a phenoxy group to react with a haloalkyl ether, adding an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide, or tetraalkylammonium, and then extracting with an organic solvent such as ethyl acetate or chloroform. Alternatively, it can be obtained by heating a primary or secondary amine to react with a haloalkyl ether having a phenoxy group at its terminal, adding an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide, or tetraalkylammonium, and then extracting with an organic solvent such as ethyl acetate or chloroform.

[0367] (Compound (PA) that has a proton-accepting functional group and decomposes upon irradiation with actinic rays or radiation to generate a compound in which the proton-accepting property is reduced or lost, or which has changed from a proton-accepting property to an acidic compound) The composition according to the present invention may further contain, as an acid diffusion controller, a compound that has a proton-accepting functional group and that decomposes upon irradiation with actinic rays or radiation to reduce or eliminate its proton-accepting properties or to generate a compound that has changed from proton-accepting properties to acidic properties (hereinafter, also referred to as compound (PA)).

[0368] The proton acceptor functional group refers to a group capable of electrostatically interacting with a proton or a functional group having electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether, or a functional group having a nitrogen atom with an unshared electron pair that does not contribute to π-conjugation. The nitrogen atom with an unshared electron pair that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure represented by the following general formula:

[0369] [ka]

[0370] Preferred partial structures of the proton acceptor functional group include, for example, a crown ether structure, an azacrown ether structure, a primary to tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure.

[0371] When irradiated with actinic rays or radiation, the compound (PA) decomposes to generate a compound in which its proton acceptor property is reduced or eliminated, or which has changed from proton acceptor property to acidic. Here, the reduction or elimination of proton acceptor property, or the change from proton acceptor property to acidic property, refers to a change in proton acceptor property resulting from the addition of a proton to a proton acceptor functional group. Specifically, when a proton adduct is formed from the compound (PA) having a proton acceptor functional group and a proton, the equilibrium constant in the chemical equilibrium decreases.

[0372] Specific examples of the compound (PA) include the following compounds: Further specific examples of the compound (PA) can be cited, for example, those described in paragraphs

[0421] to

[0428] of JP 2014-041328 A and paragraphs

[0108] to

[0116] of JP 2014-134686 A, the contents of which are incorporated herein by reference.

[0373] [ka]

[0374] [ka]

[0375] [ka]

[0376] The acid diffusion controller may be used alone or in combination of two or more. The content of the acid diffusion controller is preferably from 0.001 to 10 mass %, and more preferably from 0.005 to 5 mass %, relative to the total solid content of the resist composition.

[0377] The ratio of the photoacid generator and acid diffusion controller used in the resist composition is preferably photoacid generator / acid diffusion controller (molar ratio) = 2.5 to 300. From the viewpoint of achieving superior effects of the present invention, a molar ratio of 2.5 or more is preferred, and from the viewpoint of suppressing degradation of resolution due to thickening of the resist pattern over time after exposure until heat treatment, a molar ratio of 300 or less is preferred. The photoacid generator / acid diffusion controller (molar ratio) is more preferably 5.0 to 200, and even more preferably 7.0 to 150.

[0378] As the acid diffusion controller, for example, compounds described in paragraphs

[0140] to

[0144] of JP-A No. 2013-011833 (amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc.) can be used.

[0379] <Hydrophobic resin> The resist composition may contain a hydrophobic resin in addition to the resin (A). The hydrophobic resin is preferably designed to be unevenly distributed on the surface of the resist film, but unlike surfactants, it does not necessarily have to have a hydrophilic group in its molecule, and it does not necessarily have to contribute to uniform mixing of polar and non-polar substances. The effects of adding a hydrophobic resin include control of the static / dynamic contact angle of the resist film surface with water and suppression of outgassing.

[0380] From the viewpoint of uneven distribution in the film surface layer, the hydrophobic resin preferably has one or more of a fluorine atom, a silicon atom, and a CH3 partial structure contained in a side chain portion of the resin, and more preferably has two or more of these. Furthermore, the hydrophobic resin preferably contains a hydrocarbon group having 5 or more carbon atoms. These groups may be contained in the main chain of the resin or may be substituted on the side chain.

[0381] When the hydrophobic resin 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.

[0382] When the hydrophobic resin contains a fluorine atom, it is preferable that the hydrophobic resin has, as a partial structure having a fluorine atom, 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 has been substituted with a fluorine atom, and may further have a substituent other than a fluorine atom. The fluorine atom-containing cycloalkyl group 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 phenyl and naphthyl groups 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 repeating units having a fluorine atom or a silicon atom include those exemplified in paragraph

[0519] of US2012 / 0251948A1.

[0383] As described above, the hydrophobic resin also preferably contains 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 the CH3 partial structures possessed by an ethyl group, a propyl group, and the like. On the other hand, methyl groups directly bonded to the main chain of the hydrophobic resin (for example, α-methyl groups of repeating units having a methacrylic acid structure) are not included in the CH3 partial structure of the present invention because they have little contribution to the uneven distribution of the hydrophobic resin on the surface due to the influence of the main chain.

[0384] For details regarding hydrophobic resins, please refer to the descriptions in paragraphs

[0348] to

[0415] of JP 2014-010245 A, the contents of which are incorporated herein by reference.

[0385] In addition, as the hydrophobic resin, resins described in JP-A No. 2011-248019, JP-A No. 2010-175859, and / or JP-A No. 2012-032544 can also be preferably used.

[0386] <Surfactant> The resist composition may further contain a surfactant. By including a surfactant, it becomes possible to form a pattern with good sensitivity and resolution, poor adhesion, and fewer development defects when using an exposure light source with a wavelength of 250 nm or less, particularly 220 nm or less. As the surfactant, it is particularly preferable to use a fluorine-based and / or silicon-based surfactant. Examples of fluorine-based and / or silicone-based surfactants include those described in paragraph

[0276] of U.S. Patent Application Publication No. 2008 / 0248425. Other examples include F-TOP 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.); Troisol S-366 (manufactured by Troy Chemical Co., Ltd.); GF-300 or GF-150 (manufactured by Toa Gosei Chemical Co., Ltd.). Other examples of usable surfactants include FTOP EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802, and EF601 (manufactured by JEMCO Corporation); PF636, PF656, PF6320, and PF6520 (manufactured by OMNOVA); and FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D, and 222D (manufactured by NEOS Corporation). Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicone surfactant.

[0387] In addition to the known surfactants listed above, the surfactant may be synthesized using a fluoroaliphatic compound produced by the telomerization method (also called the telomer method) or the oligomerization method (also called the oligomer method). Specifically, a polymer having a fluoroaliphatic group derived from the fluoroaliphatic compound may be used as the surfactant. The fluoroaliphatic compound can be synthesized, for example, by the method described in JP 2002-090991 A. Additionally, surfactants other than fluorine-based and / or silicone-based surfactants described in paragraph

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

[0388] The surfactants may be used alone or in combination of two or more.

[0389] When the resist composition contains a surfactant, the content thereof is preferably from 0 to 2 mass %, more preferably from 0.0001 to 2 mass %, and even more preferably from 0.0005 to 1 mass %, relative to the total solid content of the composition.

[0390] <Other additives> The chemically amplified resist composition may further contain a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1000 or less, or an alicyclic or aliphatic compound containing a carboxyl group).

[0391] The resist composition may further comprise a dissolution inhibiting compound. Here, the "dissolution inhibiting compound" is a compound with a molecular weight of 3000 or less that is decomposed by the action of an acid and has a reduced solubility in an organic developer.

[0392] [Method for producing treatment liquid] The treatment liquid of the present invention is preferably subjected to the following purification step in order to bring the contents of metal components and organic substances with a boiling point of 300° C. or higher into desired ranges.

[0393] <Purification process> The purification step may be carried out at any time. Examples of the purification step include the following purification treatments I to IV. That is, the purification process I is a process in which the raw materials used in the production of the organic solvent contained in the treatment liquid are purified before the organic solvent is produced. The purification treatment II is a treatment for purifying the organic solvent contained in the treatment liquid during and / or after its production. The purification process III is a process in which each component is purified before mixing two or more organic solvents during the production of the treatment liquid. The purification process IV is a process in which two or more organic solvents are mixed together during the production of the treatment liquid, and then the mixture is purified. As described above, purification is preferably carried out to obtain the desired treatment solution. Purification may be carried out by mixing the individual organic solvents after purifying them, or by mixing the organic solvents together and then purifying them. In particular, the method of blending purified organic solvents is preferred because it allows the production of a constant blend ratio of organic solvents. Each of the purification treatments I to IV may be carried out only once, or may be carried out two or more times. In addition, the organic solvent to be used may be purchased as a high-purity grade product (especially one with a low content of the above-mentioned organic impurities, metal impurities, water, etc.), and may be further subjected to the purification treatment described below before use.

[0394] An example of the purification process will be described below. In the following description, the object of purification in the purification process will be simply referred to as the "liquid to be purified." Examples of the purification process include a first ion exchange process in which an ion exchange process is performed on the liquid to be purified, a dehydration process in which the liquid to be purified after the first ion exchange process is dehydrated, a distillation process in which the liquid to be purified after the dehydration process is distilled, a second ion exchange process in which an ion exchange process is performed on the liquid to be purified after the distillation process, and an organic impurity removal process in which organic impurities are removed from the liquid to be purified after the second ion exchange process, in this order. Note that the above purification process will be described below as an example, but the purification method for preparing the treatment liquid of the present invention is not limited to this. For example, a dehydration process in which the liquid to be purified is dehydrated may first be performed, followed by a distillation process in which the liquid to be purified after the dehydration process is distilled, a first ion exchange process in which an ion exchange process is performed on the liquid to be purified, and an organic impurity removal process in which organic impurities are removed from the liquid to be purified after the second ion exchange process, in this order.

[0395] The first ion exchange treatment can remove ionic components (for example, metal components) from the liquid to be purified. The first ion exchange treatment uses a first ion exchange means such as an ion exchange resin. The ion exchange resin may be a single bed of a cation exchange resin or an anion exchange resin, a double bed of a cation exchange resin and an anion exchange resin, or a mixed bed of a cation exchange resin and an anion exchange resin. In order to reduce the amount of water eluted from the ion exchange resin, it is preferable to use a dry resin that contains as little water as possible. Commercially available dry resins include Organo Corporation's 15JS-HG·DRY (trade name, dry cation exchange resin, moisture content 2% or less) and MSPS2-1·DRY (trade name, mixed bed resin, moisture content 10% or less).

[0396] The dehydration treatment can remove water from the liquid to be purified. Furthermore, when a zeolite (particularly, a molecular sieve (product name) manufactured by Union Showa Co., Ltd.) is used in the dehydration treatment, olefins can also be removed. Examples of dehydration means used in the dehydration treatment include a dehydration membrane, a water adsorbent that is insoluble in the liquid to be purified, an aeration replacement device using a dry inert gas, and a heating or vacuum heating device. When a dehydrating membrane is used, membrane dehydration is performed by pervaporation (PV) or vapor permeation (VP). The dehydrating membrane is configured, for example, as a water-permeable membrane module. The dehydrating membrane can be made of a polymeric material such as polyimide, cellulose, or polyvinyl alcohol, or an inorganic material such as zeolite. The water adsorbent is added to the liquid to be purified. Examples of the water adsorbent include zeolite, diphosphorus pentoxide, silica gel, calcium chloride, sodium sulfate, magnesium sulfate, anhydrous zinc chloride, fuming sulfuric acid, and soda lime.

[0397] The distillation process can remove impurities dissolved from the dehydration membrane, metal components in the purified liquid that are difficult to remove by the first ion exchange process, fine particles (including metal components in the form of fine particles), and water in the purified liquid. The distillation means is, for example, a single-stage distillation apparatus. Impurities are concentrated in the distillation apparatus by the distillation process, and in order to prevent some of the concentrated impurities from leaking out, the distillation means is preferably provided with a means for periodically or constantly discharging some of the liquid in which the impurities are concentrated to the outside.

[0398] The second ion exchange treatment can remove impurities that have accumulated in the distillation apparatus and that have leaked out. It can also remove eluates from pipes made of stainless steel (SUS) or the like that are used as liquid delivery lines. Examples of the second ion exchange means include a tower-shaped vessel filled with an ion exchange resin and an ion adsorption membrane. Among these, the ion adsorption membrane is preferred because it allows treatment at a high flow rate. An example of the ion adsorption membrane is Neosepta (trade name, manufactured by Astom Corporation).

[0399] Each of the above-mentioned treatments is preferably carried out in a sealed state and in an inert gas atmosphere that reduces the possibility of water being mixed into the liquid to be purified. Furthermore, to minimize the incorporation of moisture, each treatment is preferably carried out in an inert gas atmosphere with a dew point temperature of −70° C. or lower. This is because, in an inert gas atmosphere at −70° C. or lower, the moisture concentration in the gas phase is 2 ppm by mass or lower, reducing the possibility of moisture being mixed into the liquid to be purified.

[0400] In addition to the above-mentioned treatments, examples of the purification step include the adsorption purification treatment of metal components using silicon carbide, as described in International Publication No. WO2012 / 043496.

[0401] According to the organic impurity removal treatment, it is possible to remove high-boiling organic impurities (including organic substances with a boiling point of 300° C. or higher) that are contained in the purified liquid after the distillation treatment and are difficult to remove by the distillation treatment. The organic impurity removal means can be implemented, for example, by an organic impurity adsorption member equipped with an organic impurity adsorption filter capable of adsorbing organic impurities. The organic impurity adsorption member is usually configured to include the organic impurity adsorption filter and a substrate to which the impurity adsorption filter is fixed. From the viewpoint of improving the adsorption performance of organic impurities, it is preferable that the organic impurity adsorption filter has an organic skeleton on its surface that can interact with organic impurities (in other words, the surface is modified with an organic skeleton that can interact with organic impurities). Note that, as an example of having an organic skeleton on its surface that can interact with organic impurities, an organic skeleton that can interact with the organic impurities is provided on the surface of a substrate that constitutes the organic impurity adsorption filter described below. Examples of organic skeletons that can interact with organic impurities include chemical structures that react with organic impurities to capture the organic impurities in an organic impurity adsorption filter. More specifically, when the organic impurities include dioctyl phthalate, diisononyl phthalate, dioctyl adipate, or dibutyl phthalate, the organic skeleton may be a benzene ring skeleton. When the organic impurities include ethylene propylene rubber, the organic skeleton may be an alkylene skeleton. When the organic impurities include n-long-chain alkyl alcohol (a structural isomer when 1-long-chain alkyl alcohol is used as a solvent), the organic skeleton may be an alkyl group. Examples of the substrate (material) that constitutes the organic impurity adsorption filter include activated carbon-supported cellulose, diatomaceous earth, nylon, polyethylene, polypropylene, polystyrene, and fluororesin. Furthermore, the organic impurity removal filter may also be a filter in which activated carbon is fixed to a nonwoven fabric, as described in JP-A-2002-273123 and JP-A-2013-150979.

[0402] Furthermore, the organic impurity removal process is not limited to the above-described embodiment using an organic impurity adsorption filter capable of adsorbing organic impurities, but may be, for example, an embodiment in which the organic impurities are physically trapped. Organic impurities with a relatively high boiling point of 250°C or higher are often coarse (e.g., compounds with 8 or more carbon atoms), and therefore it is possible to physically trap them using a filter with a pore size of about 1 nm. For example, if dioctyl phthalate is included as an organic impurity, the structure of dioctyl phthalate is larger than 10 Å (= 1 nm). Therefore, if an organic impurity removal filter with a pore size of 1 nm is used, dioctyl phthalate cannot pass through the filter pores. In other words, dioctyl phthalate is physically captured by the filter and removed from the purified liquid. In this way, organic impurities can be removed not only by chemical interaction but also by physical removal methods. In this case, however, a filter with a pore size of 3 nm or more is used as the "filtering member" described below, and a filter with a pore size of less than 3 nm is used as the "organic impurity removal filter."

[0403] The purification step may further include, for example, purification treatment V and purification treatment VI, which will be described later. Purification treatment V and purification treatment VI may be performed at any time, for example, after purification treatment IV. The purification process V is a filtering process using a metal ion adsorbent for the purpose of removing metal ions. The purification step VI is a filtration step to remove coarse particles. The purification process V and purification process VI will be described below.

[0404] In the purification process VI, an example of a means for removing metal ions is filtering using a metal ion adsorption member equipped with a metal ion adsorption filter. The metal ion adsorption member is configured to include at least one metal ion adsorption filter, and may also be configured to include a plurality of metal ion adsorption filters stacked together depending on the desired purification level. The metal ion adsorption member is usually configured to include the metal ion adsorption filter and a substrate to which the metal ion adsorption filter is fixed. The metal ion adsorption filter has a function of adsorbing metal ions in the liquid to be purified, and is preferably an ion-exchangeable filter. Here, the metal ions to be adsorbed are not particularly limited, but are preferably Fe, Cr, Ni, and Pb, as they are likely to cause defects in semiconductor devices. The metal ion adsorption filter preferably has acid groups on its surface, such as sulfo groups and carboxyl groups, in order to improve the metal ion adsorption performance. Examples of the substrate (material) that constitutes the metal ion adsorption filter include cellulose, diatomaceous earth, nylon, polyethylene, polypropylene, polystyrene, and fluororesin.

[0405] In one embodiment of the purification process VI, the filtering means is a filtering element equipped with a filter having a particle size of 20 nm or less. By adding the filter to the liquid to be purified, particulate impurities can be removed from the liquid to be purified. Here, "particulate impurities" include particles such as dust, dirt, organic solids, and inorganic solids contained as impurities in the raw materials used in the production of the liquid to be purified, as well as particles of dust, dirt, organic solids, and inorganic solids introduced as contaminants during the purification of the liquid to be purified. These particles ultimately remain undissolved in the liquid to be purified. Furthermore, "particulate impurities" also include colloidal impurities containing metal atoms. The metal atoms are not particularly limited, but when the content of at least one metal atom selected from the group consisting of Na, K, Ca, Fe, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, and Pb (preferably Fe, Cr, Ni, and Pb) is particularly low (for example, when the content of each of the above metal atoms in the purified liquid is 1000 mass ppt or less), impurities containing these metal atoms are likely to form colloids. It is often difficult to remove colloidal impurities using the metal ion adsorbent. Therefore, colloidal impurities can be effectively removed by using a filter with a particle size of 20 nm or less (for example, a microfiltration membrane with a pore size of 20 nm or less). Particulate impurities have a size that can be removed by a filter with a particle size exclusion diameter of 20 nm or less, specifically particles with a diameter of 20 nm or more. In this specification, particulate impurities are sometimes referred to as "coarse particles." In particular, the particle removal diameter of the filter is preferably 1 to 15 nm, and more preferably 1 to 12 nm. A particle removal diameter of 15 nm or less allows for the removal of finer particulate impurities, and a particle removal diameter of 1 nm or more improves the filtration efficiency of the liquid to be purified. Here, the particle size refers to the minimum size of particles that can be removed by the filter. For example, if the particle size of a filter is 20 nm, it can remove particles with a diameter of 20 nm or more. Examples of materials for the filter include 6-nylon, 6,6-nylon, polyethylene, polypropylene, polystyrene, and fluororesin.

[0406] The filtering element may further include a filter with a particle removal size of 50 nm or more (e.g., a microfiltration membrane for removing fine particles with a pore size of 50 nm or more). When fine particles are present in the liquid to be purified in addition to colloidal impurities, particularly colloidal impurities containing metal atoms such as iron or aluminum, filtering the liquid to be purified using a filter with a particle removal size of 50 nm or more (e.g., a microfiltration membrane for removing fine particles with a pore size of 50 nm or more) before filtering using a filter with a particle removal size of 20 nm or less (e.g., a microfiltration membrane with a pore size of 20 nm or less) improves the filtration efficiency of the filter with a particle removal size of 20 nm or less (e.g., a microfiltration membrane with a pore size of 20 nm or less), and further improves the ability to remove coarse particles.

[0407] The liquid to be purified obtained by each of these treatments can be used to prepare the treatment liquid of the present invention, or can be used as the treatment liquid of the present invention itself. Although the above-described example of the purification process shows a case where all of the treatments are performed, the present invention is not limited to this, and each of the treatments may be performed alone or in combination. Furthermore, each of the treatments may be performed once or multiple times.

[0408] In addition to the above-mentioned purification process, other methods for adjusting the contents of organic substances, metal components, and water with a boiling point of 300°C or higher contained in the treatment liquid to the desired range include storing the raw materials of the organic solvent that constitutes the treatment liquid, or the treatment liquid itself, in a container that minimizes the elution of impurities. Another method is to line the inner walls of "pipes" during the production of the treatment liquid with a fluororesin to prevent the elution of metal components from the "pipes".

[0409] [Container (storage container)] The processing solution of the present invention can be filled into any container for storage, transportation, and use, as long as corrosiveness and other issues do not pose a problem. The container is preferably one that is highly clean inside and allows little elution of impurities for semiconductor applications. Specific examples of containers that can be used include, but are not limited to, the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd. The inner wall of this container (the liquid-contacting part that comes into contact with the solution inside the container) is preferably made of a non-metallic material. The non-metallic material is more preferably at least one selected from the group consisting of polyethylene resin, polypropylene resin, polyethylene-polypropylene resin, tetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), trifluorochloroethylene-ethylene copolymer (ECTFE), vinylidene fluoride resin (PVDF), trifluorochloroethylene copolymer (PCTFE), and polyvinyl fluoride resin (PVF). In particular, when a container having an inner wall made of a fluororesin is used among the above, the occurrence of the problem of elution of ethylene or propylene oligomers can be suppressed compared to when a container having an inner wall made of a polyethylene resin, a polypropylene resin, or a polyethylene-polypropylene resin is used. A specific example of such a container whose inner wall is made of a fluorine-based resin is FluoroPure PFA composite drum manufactured by Entegris, Inc. In addition, containers described on page 4 or the like of JP-A-3-502677, page 3 or the like of WO 2004 / 016526 pamphlet, and pages 9 and 16 or the like of WO 99 / 046309 pamphlet can also be used. When the inner wall is made of a non-metallic material, it is preferable that the elution of organic components in the non-metallic material into the processing liquid is suppressed.

[0410] In addition to the above-mentioned non-metallic materials, quartz or a metallic material (more preferably, an electrolytically polished metallic material; in other words, an electrolytically polished metallic material) is also preferably used for the inner wall of the container. The above-mentioned metal material (particularly the metal material used to produce the electropolished metal material) preferably contains more than 25 mass % of chromium relative to the total mass of the metal material, and examples thereof include stainless steel. The chromium content in the metal material is more preferably 30 mass % or more relative to the total mass of the metal material, and although there is no particular upper limit, it is generally preferably 90 mass % or less.

[0411] The stainless steel is not particularly limited, and any known stainless steel can be used. Among these, alloys containing 8% or more by mass of nickel are preferred, and austenitic stainless steels containing 8% or more by mass of nickel are more preferred. Examples of austenitic stainless steels include SUS (Steel Use Stainless) 304 (Ni content 8% by mass, Cr content 18% by mass), SUS304L (Ni content 9% by mass, Cr content 18% by mass), SUS316 (Ni content 10% by mass, Cr content 16% by mass), and SUS316L (Ni content 12% by mass, Cr content 16% by mass).

[0412] The method for electrolytically polishing a metal material is not particularly limited, and any known method can be used, such as those described in paragraphs

[0011] to

[0014] of JP 2015-227501 A and paragraphs

[0036] to

[0042] of JP 2008-264929 A.

[0413] It is presumed that electrolytic polishing of a metal material results in a higher chromium content in the surface passive layer than in the parent phase, and therefore metal components are less likely to leak into the solution from the inner wall coated with the electrolytically polished metal material, making it possible to obtain a solution with reduced metal components (metal impurities). The metal material is preferably buffed. The buffing method is not particularly limited, and known methods can be used. The size of the abrasive grains used for the buffing finish is not particularly limited, but #400 or smaller is preferred because it tends to reduce the surface irregularities of the metal material. It is preferable that the buffing be carried out before the electrolytic polishing. The metal material may also be processed by one or a combination of two or more of multiple stages of buffing using different grit sizes of abrasive grains, acid cleaning, and magnetic fluid polishing.

[0414] In the present invention, an entity having the container and the treatment liquid contained in the container is also referred to as a solution container.

[0415] It is preferable that the inside of these containers be cleaned before filling them with the treatment liquid. The effects of the present invention are significantly achieved when the liquid used for cleaning is the treatment liquid of the present invention itself or an organic solvent contained in the treatment liquid of the present invention. After production, the treatment liquid of the present invention may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored. The gallon bottle may be made of glass or other materials.

[0416] To prevent changes in the components of the treatment solution during storage, the container may be filled with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. Gases with low moisture content are particularly preferred. During transportation and storage, the solution may be kept at room temperature, but the temperature may be controlled to a range of -20°C to 20°C to prevent deterioration.

[0417] [Clean room] It is preferable that the manufacturing of the processing solution of the present invention, handling including opening and / or cleaning of the storage container, filling of the processing solution, processing analysis, and measurement are all carried out in a clean room. The clean room preferably meets the clean room standard of ISO 14644-1. It is preferable that the clean room meets any of ISO (International Organization for Standardization) Class 1, ISO Class 2, ISO Class 3, and ISO Class 4, more preferably ISO Class 1 or ISO Class 2, and even more preferably ISO Class 1. In the examples described below, the manufacturing of the processing solution, handling including opening and / or cleaning of the storage container, filling of the processing solution, processing analysis, and measurement were carried out in a Class 2 clean room.

[0418] [Static elimination process] The preparation and purification of the treatment liquid or the organic solvent contained in the treatment liquid of the present invention may further include a charge removal step, which is a step of removing charge from at least one selected from the group consisting of raw materials, reactants, and purified products (hereinafter referred to as "purified products, etc.") to reduce the charged potential of the purified products, etc. The method for removing static electricity is not particularly limited, and any known method can be used, for example, a method in which the purified liquid or the like is brought into contact with a conductive material. The contact time for the purified liquid or the like with the conductive material is preferably 0.001 to 60 seconds, more preferably 0.001 to 1 second, and even more preferably 0.01 to 0.1 second. Examples of conductive materials include stainless steel, gold, platinum, diamond, and glassy carbon. As a method for bringing the purified liquid or the like into contact with a conductive material, for example, a grounded mesh made of a conductive material is placed inside the pipeline and the purified liquid or the like is passed through it.

[0419] The neutralization step may be carried out at any time from the supply of raw materials to the filling of the purified product, and is preferably carried out before at least one step selected from the group consisting of a raw material supply step, a reaction step, a solution preparation step, a purification step, a filtration step, and a filling step, and more preferably before the purified product is poured into a container used in each of the above steps. This makes it possible to prevent impurities from the container from being mixed into the purified product. [Example]

[0420] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0421] [Actinic ray- or radiation-sensitive composition (resist composition)] An actinic ray- or radiation-sensitive composition (resist composition) was prepared using the materials shown below.

[0422] <Resin (A)> (Synthesis Example 1): Synthesis of Resin (A-1) Cyclohexanone (600 g) was placed in a 2 L flask, and the atmosphere was replaced with nitrogen at a flow rate of 100 mL / min for 1 hour. Then, a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) (4.60 g (0.02 mol)) was added to the flask, and the internal temperature of the flask was raised to 80°C. Next, 4-acetoxystyrene (48.66 g (0.3 mol)), 1-ethylcyclopentyl methacrylate (109.4 g (0.6 mol)), Monomer 1 (22.2 g (0.1 mol)), and polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) (4.60 g (0.02 mol)) were dissolved in cyclohexanone (200 g) to prepare a monomer solution. The monomer solution was added dropwise over 6 hours to the flask, which had been heated to an internal temperature of 80° C. After the addition was completed, the reaction was continued at an internal temperature of 80° C. for an additional 2 hours.

[0423] [ka]

[0424] The reaction solution (contents of the flask) was cooled to room temperature and then added dropwise to hexane (3 L) to obtain a mixture in which a polymer precipitated. The mixture was filtered to obtain a solid (filtered residue). The obtained solid (filtered residue) was dissolved in acetone (500 ml) and added dropwise again to hexane (3 L), and a solid (filtered residue) was obtained again in the same manner as above. The obtained solid was dried under reduced pressure to obtain 4-acetoxystyrene / 1-ethylcyclopentyl methacrylate / monomer 1 copolymer (A-1a) (160 g).

[0425] The copolymer (A-1a) (10 g), methanol (40 ml), 1-methoxy-2-propanol (200 ml), and concentrated hydrochloric acid (1.5 ml) were added to an empty flask in a reaction vessel, and the reaction solution (contents of the flask) was heated to 80 °C and stirred for 5 hours. The reaction solution was allowed to cool to room temperature and then added dropwise to distilled water (3 L) to obtain a mixed solution. The mixed solution was filtered to obtain a solid (filtered residue). The obtained solid (filtered residue) was dissolved in acetone (200 ml) and added dropwise again to distilled water (3 L), and a solid (filtered residue) was obtained again in the same manner as above. The obtained solid was dried under reduced pressure to obtain resin (A-1) (8.5 g). The weight-average molecular weight of resin (A-1) was 10,800, and the molecular weight dispersity (Mw / Mn) was 1.55.

[0426] (Synthesis Example 2): Synthesis of Resin (A-2) Resin (A-2) was synthesized in the same manner as in Synthesis Example 1, except that the monomer used was changed. The composition ratio (molar ratio) of each repeating unit in the resin was: 1 Calculation was performed using H-NMR (Nuclear Magnetic Resonance) measurements.

[0427] The table below shows the resins used in the resist compositions. In the table, the "Composition ratio (molar ratio)" column indicates the content (composition ratio (molar ratio)) of each repeating unit constituting each resin. The content of each repeating unit shown in the "Structure" column corresponds, from left to right, to the value shown in the "Composition ratio (molar ratio)" column.

[0428] [Table 1]

[0429] <Photoacid generator> The following components were used as photoacid generators:

[0430] [ka]

[0431] <Basic compounds (acid diffusion controllers)> The following components were used as basic compounds.

[0432] [ka]

[0433] <Solvent> The following components were used as the solvent: C-1: Propylene glycol monomethyl ether acetate C-2: Propylene glycol C-3: Ethyl lactate

[0434] <Preparation of Resist Composition> Each component shown in Table 2 below was dissolved in the solvent shown in the table in the proportions shown in the table. The resulting mixture was filtered using a polyethylene filter with a pore size of 0.03 μm to obtain resist compositions 1 and 2.

[0435] [Table 2]

[0436] [test] [Simple Resolution Performance Evaluation: EB Exposure Evaluation: Examples A to E and Comparative Examples A to E] A resist pattern was formed using the following procedure, using resist composition 1 shown in Table 2. Details of the resist pattern formation conditions are shown in Tables 3 and 4. In both EB and EUV exposure, the resist film is ionized by exposure, generating secondary electrons, which then decompose the photoacid generator to generate acid. Therefore, even if EB exposure is used as a simple exposure evaluation instead of EUV exposure, results similar to those of EUV exposure can be reproduced.

[0437] <Pattern Creation> (Application of resist composition and post-application baking) An organic film-forming composition (product name: AL412, manufactured by Brewer Science) was applied to a 6-inch silicon wafer and baked at 205°C for 60 seconds to form an organic film with a thickness of 20 nm. Resist composition 1 shown in Table 2 was applied thereon and baked at 120°C for 60 seconds (post-application bake) to form a resist film with a thickness of 60 nm.

[0438] (exposure) The resist film on the wafer (wafer with resist film) on which the resist film had been formed as described above was exposed using an electron beam irradiation device (G100 manufactured by Elionix Co., Ltd.; acceleration voltage 100 keV, beam current 100 pA) to form a line and space pattern (length 0.2 mm, number of lines drawn 45) with a half pitch of 22 nm at each exposure dose listed in Table 3. Specifically, exposure was performed at each exposure dose corresponding to each shot number in Table 3 shown below. The resist film was exposed (shot) at each exposure dose, and the resist film exposed at each exposure dose was subjected to the subsequent steps. The exposure amounts in Table 3 are set in order of shot number at equal logarithmic intervals. Even when the sensitivity of the resist films used for evaluation differs, it is possible to compare resolution performance by comparing the number of shots that ultimately resulted in resolution without problems (the number of exposure doses that resulted in resolution without problems).

[0439] [Table 3]

[0440] (Post Exposure Bake) After exposure, the wafer was removed from the electron beam irradiation device and immediately heated on a hot plate at a temperature of 110° C. for 60 seconds (post-exposure bake).

[0441] (Developing process) Using a shower-type developing apparatus (ADE3000S manufactured by ACTES Corporation), the wafer was rotated at 50 rpm while butyl acetate (23°C) was sprayed onto the wafer as a developer at a flow rate of 200 mL / min for 10 seconds to perform development.

[0442] (Rinse process) Thereafter, while rotating the wafer at 50 rpm, a rinse treatment was performed by discharging the treatment liquid (23°C) shown in Tables 4 to 8 onto the wafer at a flow rate of 200 mL / min for 5 seconds, and finally, the wafer was dried by rotating at high speed of 2000 rpm for 60 seconds.

[0443] <Evaluation> The patterns obtained were evaluated for the following items. Detailed results are shown in Tables 4 to 8.

[0444] (resolution) The resolution of the 22 nm line and space pattern at each exposure dose was observed using a scanning electron microscope (S-9260 manufactured by Hitachi, Ltd.) The number of shots that resolved without any problems at each exposure dose was counted to evaluate the resolution. FIG. 1 shows micrographs of patterns formed by exposure with the exposure doses of shot numbers 3 to 10 in Example A-1 and Comparative Example A-1. In Comparative Example A-1, it was determined that resolution was achieved without problems only when exposed with the exposure amount of shot number 4. In other words, in Comparative Example A-1, the number of shots (number of resolved frames) that were resolved without problems was 1. In contrast, in Example 1, it was determined that resolution was achieved without problems when exposed with the exposure doses of shot numbers 4 to 8. In other words, in Example A-1, the number of shots (number of resolved frames) that were able to be resolved without problems was 5. Based on the same criteria, the number of resolved frames was also determined for the other Examples and Comparative Examples. Evaluation was made using the following evaluation criteria. A: 5 or more B: 4 C: 3 D: 2 E: 1 or less

[0445] (Shape (film loss in exposed area)) The shape of a pattern with a line width of 22 nm at an irradiation dose showing the above sensitivity was observed using a scanning electron microscope (S-4800 manufactured by Hitachi, Ltd.), and the shape of the obtained pattern was evaluated according to the following criteria. It can be determined that the closer the pattern shape is to a rectangle, the more effectively the film loss is suppressed, and the more severe the deterioration of the pattern shape, the greater the film loss. A: Rectangle B: Slight deterioration in shape C: Significantly deteriorated shape or no resolution

[0446] (Bridge defect) The resolution of the 22 nm line and space pattern at each exposure dose was observed using a scanning electron microscope (S-9260 manufactured by Hitachi, Ltd.) The number of residual defects at the maximum exposure dose at which the pattern could be resolved without collapse was counted and evaluated according to the following criteria. A: 3 or less B: 4~10 pieces C: 11~15 pieces D: 16~30 pieces E: 31 or more

[0447] (Charging property) PFA piping (inner diameter 4 mm, outer diameter 6 mm, Nichias Naflon (R) The rinse solution was passed through the inside of the pipe at a flow rate of 0.5 L / min. The potential on the surface of the pipe was measured using a digital electrostatic potential meter (KSD-2000, manufactured by Kasuga Electric Co., Ltd.). Evaluation was based on the following criteria. (ESD risk assessment criteria) A: 500mV or less B: More than 500mV and less than 1000mV C: More than 1000mV and less than 5000mV D: More than 5000mV and less than 7500mV E: More than 7500mV

[0448] [Table 4]

[0449] [Table 5]

[0450] [Table 6]

[0451] [Table 7]

[0452] [Table 8]

[0453] [Table 9]

[0454] In the table, "boiling point difference between two solvents" means the value calculated by the following formula (Bp). Formula (Bp) "Boiling point difference between two solvents (℃)" = |Boiling point of fluorinated solvent (℃) - Boiling point of second solvent (℃)| The boiling point is the boiling point at 1 atmosphere. In Tables 4 to 8, the "skeleton" column indicates whether the second solvent has a linear structure, a branched structure, or a cyclic structure. The term "cyclic" means that the second solvent has a cyclic structure. The term "branched" means that the second solvent has a branched alkyl group and does not have a cyclic structure. The term "linear" means that the second solvent has a linear alkyl group and does not have a cyclic structure or a branched alkyl group.

[0455] <Result> The results shown in Tables 4 to 8 confirm that the desired effects can be obtained when the treatment liquid of the present invention is used as a rinse liquid.

[0456] Comparison of Examples A-1 to A-3 with Examples A-4 to A-5 etc. confirmed that a more excellent effect is achieved when the content of the fluorine-based solvent is 10 to 80 mass % relative to the total mass of the treatment liquid. The above effect can also be seen from a comparison of Examples B-1 to B-5, a comparison of Examples C-1 to C-5, a comparison of Examples D-1 to D-5, and a comparison of Examples E-1 to E-5.

[0457] Comparison of Examples A-2 and A-24 with Examples A-22 and A-44 confirmed that when the organic solvent was a non-cyclic ester solvent, the effect was superior. Furthermore, a comparison of Examples B-9 and B-18 with Examples B-2 and B-11 confirmed that when the organic solvent was an acyclic ether solvent, the effect was superior.

[0458] A comparison of Examples A-1, B-1, C-1, D-1 and E-1 confirmed that the effect was better when an ester-based solvent, an ether-based solvent, an alcohol-based solvent or a ketone-based solvent was used as the second solvent.

[0459] Comparison of Examples A-2, A-6, A-8, A-11, A-16, A-20, and A-21 confirmed that when the carbon number of the ester solvent is 8 or less, the effect is superior.

[0460] Example F-1 A pattern was formed by following the same procedure as in Example A-1, except that resist composition 2 was used instead of resist composition 1. The resolution was evaluated as C, the film loss in exposed areas was evaluated as B, the bridge defects were evaluated as A, and the charging property was evaluated as A. From the above results, it was confirmed that a more excellent effect can be obtained when the resin has a hydroxystyrene-based repeating unit.

[0461] The processing solution of the present invention can obtain the desired effects not only when used as a rinse solution as described above, but also when used as a developer. Specifically, in Example 1, even when the developer was changed to a mixed solution of butyl acetate and 2H,3H-decafluoropentane in a volume ratio of 3:2 (butyl acetate:2H,3H-decafluoropentane), a similar pattern was obtained.

Claims

1. A treatment solution for resist film patterning, which is used to perform at least one of development and washing after exposure of a resist film obtained from an actinic ray- or radiation-sensitive composition, The solvent contains a fluorine-containing solvent having 3 to 5 carbon atoms and an organic solvent other than the fluorine-containing solvent having 3 to 5 carbon atoms, The treatment liquid contains at least one organic solvent selected from the group consisting of isopropyl propionate, sec-butyl acetate, isoamyl formate, butyl acetate, diethyl carbonate, butyl butyrate, diisoamyl ether, amyl ether, anisole, 2,6-dimethyl-4-heptanol, 3-octanol, diisobutyl ketone, 3-octanone, 2,4-dimethyl-3-pentanone, and mesitylene.

2. The processing solution according to claim 1 , wherein the processing solution is a rinse solution.

3. 2. The treatment liquid according to claim 1, wherein the number of fluorine atoms contained in the fluorine-based solvent is at least twice the number of carbon atoms contained in the fluorine-based solvent.

4. 4. The treatment liquid according to claim 1, wherein the content of the fluorine-based solvent is 10 to 80% by mass relative to the total mass of the treatment liquid.

5. 2. The treatment liquid according to claim 1, wherein the fluorine-based solvent comprises at least one selected from the group consisting of 2H,3H-decafluoropentane and 1H-undecafluoropentane.

6. The treatment liquid according to claim 1 , which does not contain an alcohol-based solvent.

7. The treatment liquid according to any one of claims 1 to 6, wherein the actinic ray- or radiation-sensitive composition contains a resin having a hydroxystyrene-based repeating unit.

8. a resist film forming step of forming a resist film using the actinic ray- or radiation-sensitive composition; an exposure step of exposing the resist film to light; A pattern forming method comprising: a treatment step of treating the exposed resist film with the treatment liquid according to any one of claims 1 to 7.

9. a resist film forming step of forming a resist film using the actinic ray- or radiation-sensitive composition; an exposure step of exposing the resist film to light; a processing step of processing the exposed resist film, The processing step comprises: a developing step of developing with a developer; a rinsing step of cleaning with a rinse liquid, A pattern forming method, wherein the rinse liquid is the treatment liquid according to any one of claims 1 to 7.

10. The pattern formation method according to claim 9 , wherein the developer contains an ester-based solvent.

11. 11. The pattern formation method according to claim 10, wherein the ester-based solvent comprises at least one selected from the group consisting of butyl acetate, isobutyl acetate, tert-butyl acetate, sec-butyl acetate, amyl acetate, isoamyl acetate, amyl formate, isoamyl formate, hexyl formate, amyl propionate, isoamyl propionate, isopropyl propionate, propyl propionate, ethyl butyrate, ethyl isobutyrate, diethyl carbonate, dibutyl carbonate, butyl butanoate, isobutyl isobutyrate, ethyl isovalerate, butyl isovalerate, propyl heptanoate, ethyl heptanoate, butyl hexanoate, propyl hexanoate, and ethyl 3-methylvalerate.

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