Chemically amplified resist composition and pattern forming method

Abstract

To provide a chemically amplified resist composition which exhibits high sensitivity, improved LWR and CDU, and excellent resolution regardless of whether it is positive or negative, and a pattern forming method using the same.SOLUTION: The chemically amplified resist composition contains (A) a base polymer and (B) a quencher comprising an amine compound represented by the following formula (1). The base polymer contains a polymer P containing a repeating unit a having a structural moiety which is decomposed by irradiation with KrF excimer laser light, ArF excimer laser light, an electron beam or extreme ultraviolet rays to generate an acid.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a chemically amplified resist composition and a pattern forming method. [Background technology]

[0002] As LSIs become more highly integrated and faster, pattern rules are becoming finer at a rapid pace. In particular, the expansion of the logic memory market due to the spread of smartphones is driving miniaturization. The most advanced miniaturization technology is the mass production of 10nm node devices using double patterning with ArF immersion lithography, and preparations are underway for the mass production of 7nm node devices using double patterning for the next generation. Extreme ultraviolet (EUV) lithography is being considered as a candidate for the next-generation 5nm node.

[0003] While logic devices are becoming more miniaturized, flash memory devices have become devices with stacked gates called 3D-NAND, and the capacity is increasing by increasing the number of layers. As the number of layers increases, the hard masks used to process them become thicker, and the photoresist film also becomes thicker. The resist for logic devices is becoming thinner, while the resist for 3D-NAND is becoming thicker.

[0004] As miniaturization progresses and approaches the diffraction limit of light, the contrast of light decreases. This decrease in contrast of light causes a decrease in the resolution of hole and trench patterns and a decrease in focus margin in positive resist films. Increasing the thickness of resist films will restore the film thickness of resist films used for previous generation devices, but higher dimensional uniformity (CDU) is required, which cannot be met with previous photoresist compositions. In order to prevent a decrease in the resolution of resist patterns due to a decrease in the contrast of light caused by smaller dimensions, or to improve CDU when thickening resist films, attempts are being made to improve the dissolution contrast of resist films.

[0005] For chemically amplified positive resist compositions in which an acid generator is added and an acid is generated by irradiation with light or an electron beam (EB) to cause a deprotection reaction by the acid, and for chemically amplified negative resist compositions in which a polarity change reaction or a crosslinking reaction by the acid is caused, the addition of a quencher (acid diffusion control agent) for the purpose of controlling the diffusion of the acid to the unexposed area and improving the contrast has been very effective. For this reason, many amine quenchers have been proposed (Patent Documents 1 and 2). However, since the amine quencher is partially volatilized during post-exposure baking (PEB), it is not possible to appropriately control the acid diffusion. It has also been considered to prevent volatilization by applying an amine compound having a long-chain alkyl group or a bulky structure, but in that case, the amine compound has a highly liposoluble structure, which inhibits solubility in an alkaline developer and impairs resolution.

[0006] Various quenchers of onium salt type, instead of amine structure, have also been developed. The acid labile group used in the (meth)acrylate polymer for the ArF resist composition undergoes a deprotection reaction by using a photoacid generator that generates a sulfonic acid substituted with a fluorine atom at the α-position, but the deprotection reaction does not proceed with an acid generator that generates a sulfonic acid or carboxylic acid not substituted with a fluorine atom at the α-position. When a sulfonium salt or iodonium salt that generates a sulfonic acid not substituted with a fluorine atom at the α-position is mixed with a sulfonium salt or iodonium salt that generates a sulfonic acid not substituted with a fluorine atom at the α-position, the sulfonium salt or iodonium salt that generates a sulfonic acid not substituted with a fluorine atom at the α-position undergoes ion exchange with the sulfonic acid not substituted with a fluorine atom at the α-position. The sulfonic acid generated by light and substituted with a fluorine atom at the α-position is reverted to a sulfonium salt or iodonium salt by ion exchange, so the sulfonium salt or iodonium salt of the sulfonic acid or carboxylic acid not substituted with a fluorine atom at the α-position functions as a quencher. A resist composition having such a function has been proposed (Patent Document 3).

[0007] This photodegradable onium salt type quencher has been highly effective in improving line width roughness (LWR) and CDU. However, these materials have a photosensitive structure, and absorb light with a wavelength of 193 nm in ArF lithography, for example, which reduces the transmittance of the resist film. This causes the cross-sectional shape of the pattern to become tapered in the case of a positive resist composition. In addition, the photodegradable onium salt type quencher reduces the resolution because the photodecomposition product inhibits the solubility of the developer. For these reasons, it is no longer possible to take the approach of increasing the amount of the quencher to increase the acid diffusion control ability.

[0008] A technique for incorporating a photoacid generator into a base polymer is also effective as a method for controlling acid diffusion. For example, a sulfonium salt having a partially fluorinated alkane sulfonate anion as a polymerizable unit has been disclosed (Patent Document 4). However, in the ultra-miniaturization generation of 10 nm node or less, even the use of such a technique has not yet satisfied LWR or CDU. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2001-194776 A [Patent Document 2] JP 2002-226470 A [Patent Document 3] International Publication No. 2008 / 066011 [Patent Document 4] JP 2008-133448 A Summary of the Invention [Problem to be solved by the invention]

[0010] It is desirable to develop a chemically amplified resist composition that uses an acid as a catalyst, which can improve the LWR of a line pattern and the CDU of a hole pattern, while also improving resolution performance. To achieve this, it is necessary to further reduce the diffusion distance of the acid and at the same time improve the contrast, which are two contradictory properties.

[0011] The present invention has been made in consideration of the above circumstances, and has an object to provide a chemically amplified resist composition which has high sensitivity, improved LWR and CDU, and excellent resolution, whether positive or negative, and a pattern formation method using the same. [Means for solving the problem]

[0012] Means for Solving the Problems The present inventors have conducted extensive research in order to achieve the above object, and as a result have found that by using a specific polymer and an amine compound as a quencher, a chemically amplified resist composition can be obtained which has improved LWR and CDU, high contrast, excellent resolution, and a wide process margin, and have thus completed the present invention.

[0013] That is, the present invention provides the following chemically amplified resist composition and pattern forming method. 1. A chemically amplified resist composition comprising (A) a base polymer and (B) a quencher comprising an amine compound represented by the following formula (1): The chemically amplified resist composition comprises a polymer P, wherein the base polymer comprises a repeating unit a having a structural moiety that decomposes upon irradiation with KrF excimer laser light, ArF excimer laser light, EB or EUV to generate an acid. [ka] (In the formula, m is an integer of 0 to 10. R N1 and R N2are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with halogen atoms, and -CH2- constituting the hydrocarbyl group may be substituted with -O- or -C(=O)-. N1 and R N2 may be bonded to each other to form a ring together with the nitrogen atom to which they are attached, and the ring may contain -O- or -S-. N1 and R N2 cannot simultaneously become a hydrogen atom. X L is a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. L a1 is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond. Ring R R1 is a (m+1)-valent heterocyclic group having 2 to 20 carbon atoms and having a lactone structure, lactam structure, sultone structure or sultam structure. R 11 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. When m is 2 or more, each R 11 may be the same or different, and there may be two or more R 11 are combined together to form R R1 It may form a ring with the above atoms.) 2. The chemically amplified resist composition according to 1, wherein the repeating unit a is represented by the following formula (a1) or (a2): [ka] (In the formula, R A is a hydrogen atom or a methyl group. R B is a hydrogen atom, a methyl group, or a trifluoromethyl group. X 1 is a phenylene group or a naphthylene group. X 2 is -O- or -N(H)-. Y Lis a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. R f1 and R f2 each independently represents a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms. n is an integer from 0 to 3. Za + is an onium cation. 3. The chemically amplified resist composition according to 1, wherein the repeating unit a is represented by the following formula (a3): [ka] (In the formula, R C is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. L is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Af is a hydrogen atom or a trifluoromethyl group. k is 0 or 1, provided that when L is a single bond, k is 0. Zb + is an onium cation. 4. The chemically amplified resist composition according to any one of 1 to 3, wherein the polymer P further contains a repeating unit represented by the following formula (b1) or (b2): [ka] (In the formula, R C each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y 1 is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OY 11 - and Y 11 is an alkanediyl group having 1 to 10 carbon atoms which may contain a hydroxy group, an ether bond, an ester bond or a lactone ring, or a phenylene group or naphthylene group. Y 2 is a single bond or *-C(=O)-O-. * indicates a bond to a carbon atom in the main chain. AL 1 and A.L. 2 are each independently an acid labile group. R 1 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. a is an integer from 0 to 4. 5. The chemically amplified resist composition according to any one of 1 to 4, wherein the polymer P further contains a repeating unit represented by the following formula (c1) or (c2): [ka] (In the formula, R C each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A p is a hydrogen atom, or a polar group containing at least one structure selected from a hydroxy group, a cyano group, a carbonyl group, a carboxy group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (-C(=O)-OC(=O)-). Y 3 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. R 2 represents a halogen atom, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylcarbonyl group having 2 to 20 carbon atoms which may contain a heteroatom. b is an integer from 1 to 4; c is an integer from 0 to 4, provided that 1≦b+c≦5. 6. Any of the chemically amplified resist compositions according to 1 to 5, further comprising a photoacid generator. 7. The chemically amplified resist composition according to any one of 1 to 6, further comprising a quencher other than the amine compound represented by formula (1). 8. Any one of the chemically amplified resist compositions according to 1 to 7, further comprising a surfactant. 9. A pattern forming method comprising the steps of forming a resist film on a substrate using any one of the chemically amplified resist compositions according to 1 to 8, exposing the resist film to KrF excimer laser light, ArF excimer laser light, EB or EUV, and developing the exposed resist film using a developer. Effect of the Invention

[0014] The chemically amplified resist composition of the present invention has a high acid diffusion controllability, and therefore is excellent in LWR and CDU, and is capable of constructing a high-resolution pattern profile. [Brief description of the drawings]

[0015] [Figure 1] 1 is a 1H-NMR spectrum of compound Q-1 obtained in Synthesis Example 1-1. [Diagram 2] 1 is a 1H-NMR spectrum of compound Q-2 obtained in Synthesis Example 1-2. [Diagram 3] 1 is a 1H-NMR spectrum of compound Q-3 obtained in Synthesis Example 1-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The chemically amplified resist composition of the present invention contains, as essential components, (A) a base polymer containing a specific polymer, and (B) an amine compound having a specific structure.

[0017] [(A) Base polymer] The base polymer of the component (A) contains a polymer P containing a repeating unit a having a structural portion that decomposes upon irradiation with KrF excimer laser light, ArF excimer laser light, EB or EUV (hereinafter, these are also collectively referred to as high energy rays) to generate an acid. The structural portion that is sensitized by high energy rays to generate an acid is not particularly limited, but examples thereof include nonionic compounds such as nitrobenzylsulfonate, imide sulfonate, oxime sulfonate, diazosulfone, arylsulfonate, β-ketosulfonate, and N-arylsulfonimide, and ionic compounds such as sulfonium salts and iodonium salts. For such photoacid generating portions, see Tomotaka Tsuchiyama, Journal of Photopolymer Science Technology, Vol. 33, No.1, 2020, p15-26.

[0018] The structural moiety of the repeating unit a that generates an acid is preferably an ionic structural moiety, more preferably an ionic structural moiety containing a sulfonium salt or an iodonium salt. This ionic structural moiety may have a cationic moiety incorporated in a side chain of the polymer P, or an anionic moiety incorporated in a side chain of the polymer P. From the viewpoint of suppressing acid diffusion, however, a structure in which an anionic moiety is incorporated in a side chain of the polymer P is preferred.

[0019] The repeating unit a is preferably one represented by the following formula (a1) or (a2). [ka]

[0020] In formulas (a1) and (a2), R A R is a hydrogen atom or a methyl group. B is a hydrogen atom, a methyl group, or a trifluoromethyl group. 1 is a phenylene group or a naphthylene group. 2 is -O- or -N(H)-.

[0021] In formulas (a1) and (a2), Y L is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a single bond or a heteroatom. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkanediyl groups having 1 to 20 carbon atoms, such as a methanediyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; a cyclopentanediyl group, and a cyclohexanediyl group. cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms, such as a norbornanediyl group or an adamantanediyl group; arylene groups having 6 to 20 carbon atoms, such as a phenylene group, a methylphenylene group, an ethylphenylene group, an n-propylphenylene group, an isopropylphenylene group, an n-butylphenylene group, an isobutylphenylene group, a sec-butylphenylene group, a tert-butylphenylene group, a naphthylene group, a methylnaphthylene group, an ethylnaphthylene group, an n-propylnaphthylene group, an isopropylnaphthylene group, an n-butylnaphthylene group, an isobutylnaphthylene group, a sec-butylnaphthylene group or a tert-butylnaphthylene group; and groups obtained by combining these. In addition, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- constituting the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbylene group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0022] In formulas (a1) and (a2), R f1 and R f2 are each independently a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and preferably a fluorine atom or a trifluoromethyl group. n is an integer of 0 to 3.

[0023] In the formulas (a1) and (a2), Za + is an onium cation. The onium cation is preferably a sulfonium cation or an iodonium cation.

[0024] The sulfonium cation includes those represented by the following formula (Z1). [ka]

[0025] In formula (Z1), R Z1 , R Z2 and R Z3 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. Z1 , R Z2 and R Z3 Any two of R may be bonded to each other to form a ring together with the sulfur atom to which they are attached. Z1 , R Z2 and R Z3 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a tert-pentyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, or an n-decyl group; a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclopentylbutyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a cyclohexylbutyl group, a norbornyl group, a tricyclo[5.2.1.0 2,6]Cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as decanyl group, adamantyl group, and adamantylmethyl group; aryl groups having 6 to 20 carbon atoms, such as phenyl group, naphthyl group, and anthracenyl group; and groups obtained by combining these. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom, such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH2- constituting the hydrocarbyl group may be substituted with a group containing a heteroatom, such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0026] Specific examples of the sulfonium cation include triphenylsulfonium cation, 4-hydroxyphenyldiphenylsulfonium cation, bis(4-hydroxyphenyl)phenylsulfonium cation, tris(4-hydroxyphenyl)sulfonium cation, 4-tert-butoxyphenyldiphenylsulfonium cation, bis(4-tert-butoxyphenyl)phenylsulfonium cation, tris(4-tert-butoxyphenyl)sulfonium cation, 3-tert-butoxyphenyldiphenylsulfonium cation, bis(3-tert-butoxyphenyl)phenylsulfonium cation, tris(3-tert-butoxyphenyl)sulfonium cation, 3,4-di-tert-butoxyphenyldiphenylsulfonium cation, bis(3,4-di-tert-butoxyphenyl)phenylsulfonium cation, tris(3,4-di-tert-butoxyphenyl)sulfonium cation, diphenyl(4-thiophenoxyphenyl)sulfonium cation, 4-tert-butoxycarbonylmethyloxyphenyldiphenylsulfonium cation, tris(4-tert-butoxycarbonylmethyloxyphenyl)sulfonium cation, (4-tert-butoxyphenyl)bis(4-dimethylaminophenyl)sulfonium cation, tris(4-dimethylaminophenyl)sulfonium cation, 2-naphthyldiphenylsulfonium cation, (4-hydroxy-3,5-dimethylphenyl)diphenylsulfonium cation, (4-n-hexyloxy-3,5-dimethylphenyl)diphenylsulfonium cation, dimethyl(2-naphthyl)sulfonium cation, 4-hydroxyphenyldimethylsulfonium cation, 4-methoxyphenyldimethylsulfonium cation, trimethylsulfonium cation, 2-oxocyclohexylcyclohexylmethylsulfonium cation, trinaphthylsulfonium cation, tribenzylsulfonium cation, diphenylmethylsulfonium cation, dimethylphenylsulfonium cation, 2-oxo-2-phenylethylthiacyclopentanium cation, diphenyl-2-thienylsulfonium cation, 4-n-butoxynaphthyl-1-thiacyclopentanium cation, 2-n-butoxynaphthyl-1-thiacyclopentanium cation, 4-methoxynaphthyl-1-thiacyclopentanium cation, 2-methoxynaphthyl-1-thiacyclopentanium cation, and the like. Preferred examples include triphenylsulfonium cation, 4-tert-butylphenyldiphenylsulfonium cation, 4-tert-butoxyphenyldiphenylsulfonium cation, tris(4-tert-butylphenyl)sulfonium cation, tris(4-tert-butoxyphenyl)sulfonium cation, and dimethylphenylsulfonium cation.

[0027] Other specific examples of the sulfonium cation include those represented by the following formula: [ka]

[0028] The iodonium cation includes those represented by the following formula (Z2). [ka]

[0029] In formula (Z2), R Z4 and R Z5 R is each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. Z4and R Z5 Specifically, R Z1 , R Z2 and R Z3 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0030] Specific examples of the iodonium cation include diphenyliodonium cation, bis(4-methylphenyl)iodonium cation, bis(4-ethylphenyl)iodonium cation, bis(4-tert-butylphenyl)iodonium cation, bis(4-(1,1-dimethylpropyl)phenyl)iodonium cation, bis(4-methoxyphenyl)iodonium cation, 4-methoxyphenylphenyliodonium cation, 4-tert-butoxyphenylphenyliodonium cation, 4-acryloyloxyphenylphenyliodonium cation, and 4-methacryloyloxyphenylphenyliodonium cation.

[0031] Regarding the repeating unit a, specific examples of a structure in which an anion is incorporated in the side chain of a polymer include those described in paragraphs

[0046] to

[0065] of JP2011-70033A, but are not limited to these.

[0032] The repeating unit a is also preferably one represented by the following formula (a3). [ka]

[0033] In formula (a3), R C is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0034] In formula (a3), L is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a single bond or a heteroatom. The hydrocarbylene group having 1 to 20 carbon atoms represented by L may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include Y LExamples of the hydrocarbylene group represented by the formula (I) include the same as those exemplified above.

[0035] In formula (a3), Af is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group.

[0036] k is 0 or 1, provided that when L is a single bond, k is 0.

[0037] Examples of the anion of the repeating unit represented by formula (a3) ​​include, but are not limited to, those shown below. In the following formula, R C is the same as above. [ka]

[0038] [ka]

[0039] In formula (a3), Zb + is an onium cation. The onium cation is preferably a sulfonium cation or an iodonium cation, and more preferably a sulfonium cation. The sulfonium cation may be one represented by formula (Z1), and the iodonium cation may be one represented by formula (Z2).

[0040] Specific examples of the repeating unit represented by formula (a3) ​​include any combination of the specific examples of the anion and the specific examples of the sulfonium cation represented by formula (Z1) or the specific examples of the iodonium cation represented by formula (Z2).

[0041] The method for synthesizing monomer a corresponding to the repeating unit a is not particularly limited, but examples thereof include a synthesis method in which an acid anion having a polymerizable unsaturated bond corresponding to the repeating unit is exchanged for a halide of a known onium salt.

[0042] More specifically, a metal ion salt (e.g., sodium ion, potassium ion, etc.) or an ammonium salt (ammonium, triethylammonium salt, etc.) of an acid having a polymerizable unsaturated bond corresponding to the repeating unit and an onium salt having a halogen ion (chloride ion, bromide ion, iodide ion, etc.) are stirred in the presence of water or methanol to carry out an anion exchange reaction, and the mixture is separated and washed with an organic solvent such as dichloromethane, chloroform, ethyl acetate, methyl isobutyl ketone, tetrahydroxyfuran, etc. and water, thereby synthesizing the target monomer a.

[0043] Alternatively, the compound can be synthesized by stirring in the presence of an organic solvent that can be separated from water, such as dichloromethane, chloroform, ethyl acetate, methyl isobutyl ketone, or tetrahydroxyfuran, and water to carry out an anion exchange reaction, followed by separation and washing with water.

[0044] The polymer P preferably further has a repeating unit that is decomposed by the action of an acid to generate an alkali-soluble group. As such a repeating unit, the one represented by the following formula (b1) (hereinafter also referred to as repeating unit b1) or the one represented by the following formula (b2) (hereinafter also referred to as repeating unit b2) is preferable. [ka]

[0045] In formulas (b1) and (b2), R C Y each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OY 11 - and Y 11 Y is an alkanediyl group having 1 to 10 carbon atoms which may contain a hydroxy group, an ether bond, an ester bond or a lactone ring, or a phenylene group or a naphthylene group. 2 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. AL1 and A.L. 2 are each independently an acid labile group.

[0046] In formula (b2), R 1 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 11 Examples of the hydrocarbyl group having 1 to 20 carbon atoms include the same as those exemplified above. a is an integer of 0 to 4, and preferably 0 or 1.

[0047] Y in formula (b1) 1 Examples of structures in which R is changed include, but are not limited to, those shown below. A and A.L. 1 is the same as above. [ka]

[0048] [ka]

[0049] A polymer containing the repeating unit b1 is decomposed by the action of an acid to produce a carboxy group, and becomes alkali-soluble.

[0050] AL 1 and A.L. 2 The acid labile group represented by the formula (I) is not particularly limited, but preferred examples include groups selected from the following formulae (L1) to (L4), tertiary hydrocarbyl groups having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, trialkylsilyl groups in which each alkyl group has 1 to 6 carbon atoms, carbonyl groups, and saturated hydrocarbyl groups having 4 to 20 carbon atoms and containing an ether bond or an ester bond. [ka] (In the formula, * represents a bond.)

[0051] In formula (L1), R L01 and R L02 is a hydrogen atom or a saturated hydrocarbyl group having 1 to 18 carbon atoms. The saturated hydrocarbyl group may be linear, branched or cyclic, and specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-octyl and 2-ethylhexyl groups; and cyclic saturated hydrocarbyl groups such as cyclopentyl, cyclohexyl, norbornyl, tricyclodecanyl, tetracyclododecanyl and adamantyl groups. The saturated hydrocarbyl group preferably has 1 to 10 carbon atoms.

[0052] R L03 is a hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and may contain a group containing a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic, but is preferably a saturated hydrocarbyl group. In addition, some or all of the hydrogen atoms of the saturated hydrocarbyl group may be substituted with a hydroxy group, a saturated hydrocarbyloxy group, an oxo group, an amino group, a saturated hydrocarbylamino group, or the like, and some of the -CH2- constituting the saturated hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom. Examples of the saturated hydrocarbyl group include L01 and R L02 Examples of the saturated hydrocarbyl group represented by the formula (I) include the same as those mentioned above. Examples of the substituted saturated hydrocarbyl group include the groups shown below. [ka] (In the formula, * represents a bond.)

[0053] R L01 , R L02 and R L03Any two of R may be bonded to each other to form a ring together with the carbon atom or the carbon atom and oxygen atom to which they are bonded. When a ring is formed, R L01 , R L02 and R L03 are each independently an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms.

[0054] In formula (L2), R L04 is a tertiary hydrocarbyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trialkylsilyl group in which each alkyl group has 1 to 6 carbon atoms, a carbonyl group, a saturated hydrocarbyl group containing an ether bond or an ester bond and having 4 to 20 carbon atoms, or a group represented by formula (L1). x is an integer of 0 to 6.

[0055] R L04 The tertiary hydrocarbyl group represented by the formula (I) may be branched or cyclic, and specific examples thereof include tert-butyl, tert-pentyl, 1,1-diethylpropyl, 2-cyclopentylpropan-2-yl, 2-cyclohexylpropan-2-yl, 2-(bicyclo[2.2.1]heptan-2-yl)propan-2-yl, 2-(adamantan-1-yl)propan-2-yl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, and 2-ethyl-2-adamantyl. The trialkylsilyl group includes trimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. Examples of the saturated hydrocarbyl group containing a carbonyl group, an ether bond or an ester bond include a 3-oxocyclohexyl group, a 4-methyl-2-oxooxan-4-yl group, and a 5-methyl-2-oxooxolan-5-yl group.

[0056] In formula (L3), R L05is an optionally substituted saturated hydrocarbyl group having 1 to 8 carbon atoms or an optionally substituted aryl group having 6 to 20 carbon atoms. The optionally substituted saturated hydrocarbyl group may be linear, branched or cyclic, and specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl and n-hexyl groups; cyclic saturated hydrocarbyl groups such as cyclopentyl and cyclohexyl groups; and groups in which some or all of the hydrogen atoms have been substituted with a hydroxy group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a carboxy group, a saturated hydrocarbylcarbonyl group having 1 to 6 carbon atoms, an oxo group, an amino group, a saturated hydrocarbylamino group having 1 to 6 carbon atoms, a cyano group, a mercapto group, a saturated hydrocarbylthio group having 1 to 6 carbon atoms, a sulfo group or the like. Examples of the optionally substituted aryl group include a phenyl group, a methylphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, and groups in which some or all of the hydrogen atoms of these groups have been substituted with a hydroxy group, a saturated hydrocarbyloxy group having 1 to 10 carbon atoms, a carboxy group, a saturated hydrocarbylcarbonyl group having 1 to 10 carbon atoms, an oxo group, an amino group, a saturated hydrocarbylamino group having 1 to 10 carbon atoms, a cyano group, a mercapto group, a saturated hydrocarbylthio group having 1 to 10 carbon atoms, a sulfo group, or the like.

[0057] In formula (L3), y is 0 or 1; z is an integer of 0 to 3; and 2y+z=2 or 3.

[0058] In formula (L4), R L06 is an optionally substituted saturated hydrocarbyl group having 1 to 8 carbon atoms or an optionally substituted aryl group having 6 to 20 carbon atoms. Specific examples of the optionally substituted saturated hydrocarbyl group and the optionally substituted aryl group include R L05 Examples of the compound represented by the formula (I) include the same compounds as those exemplified above.

[0059] R L07 ~R L16are each independently a hydrogen atom or an optionally substituted hydrocarbyl group having 1 to 15 carbon atoms. The hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic, although a saturated hydrocarbyl group is preferred. Examples of the hydrocarbyl group include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl; cyclic saturated hydrocarbyl groups such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, and cyclohexylbutyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with a hydroxy group, a saturated hydrocarbyloxy group having 1 to 10 carbon atoms, a carboxy group, a saturated hydrocarbyloxycarbonyl group having 1 to 10 carbon atoms, an oxo group, an amino group, a saturated hydrocarbylamino group having 1 to 10 carbon atoms, a cyano group, a mercapto group, a saturated hydrocarbylthio group having 1 to 10 carbon atoms, or a sulfo group. L07 ~R L16 Two selected from these may be bonded to each other to form a ring together with the carbon atom to which they are bonded (for example, R L07 and R L08 , R L07 and R L09 , R L07 and R L10 , R L08 and R L10 , R L09 and R L10 , R L11 and R L12 , R L13 and R L14 In this case, the group participating in the ring formation is a hydrocarbylene group having 1 to 15 carbon atoms. Examples of the hydrocarbylene group include those obtained by removing one hydrogen atom from the above-mentioned examples of the hydrocarbyl group. L07 ~R L16 may bond to adjacent carbon atoms without any intermediate bond to form a double bond (for example, R L07 and R L09 , RL09 and R L15 , R L13 and R L15 , R L14 and R L15 etc.).

[0060] Among the acid labile groups represented by formula (L1), linear or branched ones include the groups shown below, but are not limited to these. [ka] (In the formula, * represents a bond.)

[0061] Among the acid labile groups represented by formula (L1), examples of cyclic groups include a tetrahydrofuran-2-yl group, a 2-methyltetrahydrofuran-2-yl group, a tetrahydropyran-2-yl group, and a 2-methyltetrahydropyran-2-yl group.

[0062] Examples of the acid labile group represented by formula (L2) include a tert-butoxycarbonyl group, a tert-butoxycarbonylmethyl group, a tert-pentyloxycarbonyl group, a tert-pentyloxycarbonylmethyl group, a 1,1-diethylpropyloxycarbonyl group, a 1,1-diethylpropyloxycarbonylmethyl group, a 1-ethylcyclopentyloxycarbonyl group, a 1-ethylcyclopentyloxycarbonylmethyl group, a 1-ethyl-2-cyclopentenyloxycarbonyl group, a 1-ethyl-2-cyclopentenyloxycarbonylmethyl group, a 1-ethoxyethoxycarbonylmethyl group, a 2-tetrahydropyranyloxycarbonylmethyl group, and a 2-tetrahydrofuranyloxycarbonylmethyl group.

[0063] Examples of the acid labile group represented by formula (L3) include a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a 1-n-propylcyclopentyl group, a 1-isopropylcyclopentyl group, a 1-n-butylcyclopentyl group, a 1-sec-butylcyclopentyl group, a 1-cyclohexylcyclopentyl group, a 1-(4-methoxy-n-butyl)cyclopentyl group, a 1-methylcyclohexyl group, a 1-ethylcyclohexyl group, a 3-methyl-1-cyclopenten-3-yl group, a 3-ethyl-1-cyclopenten-3-yl group, a 3-methyl-1-cyclohexen-3-yl group, and a 3-ethyl-1-cyclohexen-3-yl group.

[0064] As the acid labile group represented by formula (L4), groups represented by the following formulae (L4-1) to (L4-4) are particularly preferred. [ka]

[0065] In the formulae (L4-1) to (L4-4), ** represents the bonding position and bonding direction. L41 are each independently a hydrocarbyl group having 1 to 10 carbon atoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic, but is preferably a saturated hydrocarbyl group. Examples of the hydrocarbyl group include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, and n-hexyl groups; and cyclic saturated hydrocarbyl groups such as cyclopentyl and cyclohexyl groups.

[0066] The groups represented by formulae (L4-1) to (L4-4) may have stereoisomers (enantiomers or diastereomers), and formulae (L4-1) to (L4-4) represent all of these stereoisomers. When the acid labile group is a group represented by formula (L4), it may contain multiple stereoisomers.

[0067] For example, formula (L4-3) represents one or a mixture of two selected from groups represented by the following formulae (L4-3-1) and (L4-3-2). [ka] (In the formula, R L41 and ** are the same as above.)

[0068] Moreover, the formula (L4-4) represents one or a mixture of two or more selected from the groups represented by the following formulae (L4-4-1) to (L4-4-4). [ka] (In the formula, R L41 and ** are the same as above.)

[0069] Formulae (L4-1) to (L4-4), (L4-3-1), (L4-3-2), and (L4-4-1) to (L4-4-4) are also intended to represent their enantiomers and mixtures of enantiomers.

[0070] In addition, the bonding directions of the formulae (L4-1) to (L4-4), (L4-3-1), (L4-3-2), and (L4-4-1) to (L4-4-4) are on the exo side of the bicyclo[2.2.1]heptane ring, respectively, thereby realizing high reactivity in the acid-catalyzed elimination reaction (see JP 2000-336121 A). In the production of a monomer having a tertiary exo-saturated hydrocarbyl group having a bicyclo[2.2.1]heptane skeleton as a substituent, a monomer substituted with an endo-alkyl group represented by the following formulae (L4-1-endo) to (L4-4-endo) may be included, but in order to realize good reactivity, the exo ratio is preferably 50 mol% or more, and more preferably 80 mol% or more. [ka] (In the formula, R L41 and ** are the same as above.)

[0071] Examples of the acid labile group represented by formula (L4) include, but are not limited to, the groups shown below. [ka] (In the formula, ** is the same as above.)

[0072] Also, AL 1 and A.L. 2 Among the acid labile groups represented by the formula (I), the tertiary hydrocarbyl group having 4 to 20 carbon atoms, the trialkylsilyl group in which each alkyl group has 1 to 6 carbon atoms, and the saturated hydrocarbyl group having 4 to 20 carbon atoms and containing a carbonyl group, an ether bond or an ester bond are each represented by the formula (I): L04 Examples of the examples are similar to those given in the description of .

[0073] Examples of the repeating unit b1 include, but are not limited to, those shown below. In the following formula, R C is the same as above. [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] These specific examples are Y 1is a single bond, but Y 1 Even when Y is other than a single bond, it can be combined with a similar acid labile group. 1 Specific examples of when is other than a single bond are as described above.

[0079] A polymer containing the repeating unit b2 is decomposed by the action of an acid to generate a hydroxyl group, similar to the repeating unit b1, and becomes soluble in an alkali. Examples of the repeating unit b2 include, but are not limited to, those shown below. In the following formula, R C is the same as above. [ka]

[0080] [ka]

[0081] It is preferable that the polymer P further contains a repeating unit represented by the following formula (c1) (hereinafter also referred to as repeating unit c1) or a repeating unit represented by the following formula (c2) (hereinafter also referred to as repeating unit c2). [ka]

[0082] In formula (c1) or (c2), R C are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. p is a hydrogen atom, or a polar group containing at least one structure selected from a hydroxyl group, a cyano group, a carbonyl group, a carboxyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (-C(=O)-OC(=O)-). 3 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. R 2is a halogen atom, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylcarbonyl group having 2 to 20 carbon atoms which may contain a heteroatom. b is an integer of 1 to 4. c is an integer of 0 to 4, with the proviso that 1≦b+c≦5.

[0083] Examples of the repeating unit c1 include, but are not limited to, those shown below. In the following formula, R C is the same as above. [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091]

change

[0092]

change

[0093]

change

[0094]

change

[0095]

change

[0096]

change

[0097]

change

[0098]

change

[0099]

change

[0100]

change

[0101] Examples of the repeating unit c2 include, but are not limited to, those shown below. In the following formula, R C is the same as above. [ka]

[0102] [ka]

[0103] As the repeating unit c1 or c2, in ArF lithography, those having a lactone ring as a polar group are particularly preferred, while in KrF lithography, EB lithography and EUV lithography, those having a phenol moiety are preferred.

[0104] The polymer P may further contain other repeating units than those described above. For example, substituted acrylic esters such as methyl methacrylate, methyl crotonate, dimethyl maleate, and dimethyl itaconate; unsaturated carboxylic acids such as maleic acid, fumaric acid, and itaconic acid; norbornene, norbornene derivatives, tetracyclo[6.2.1.1 3,6 .0 2,7 ] The copolymer may contain repeating units derived from cyclic olefins such as dodecene derivatives; unsaturated acid anhydrides such as itaconic anhydride; or other monomers.

[0105] The weight average molecular weight (Mw) of the polymer P is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. If Mw is within this range, sufficient etching resistance is obtained, and there is no risk of a decrease in resolution due to the inability to ensure a difference in dissolution rate before and after exposure. In the present invention, Mw is a value measured in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0106] When the molecular weight distribution (Mw / Mn) of the polymer P is broad, low molecular weight and high molecular weight polymers are present, which may result in foreign matter being found on the pattern or deterioration of the pattern shape after exposure. Therefore, since the effect of Mw / Mn tends to become greater as the pattern rule becomes finer, in order to obtain a chemically amplified resist composition that is suitable for use with fine pattern dimensions, it is preferable that the Mw / Mn of the polymer has a narrow distribution of 1.0 to 2.0.

[0107] To synthesize the polymer P, for example, a monomer that provides the repeating unit described above may be polymerized in an organic solvent by adding a radical polymerization initiator and heating the resulting mixture.

[0108] An example of a method for synthesizing the polymer P includes a method in which one or more monomers having an unsaturated bond are polymerized by adding a radical initiator in an organic solvent and heating. Examples of organic solvents used in the polymerization reaction include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ethene (MEK), propylene glycol monomethyl ether acetate (PGMEA), and γ-butyrolactone (GBL). Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The amount of these initiators added is preferably 0.01 to 25 mol% based on the total amount of monomers to be polymerized. The reaction temperature is preferably 50 to 150° C., more preferably 60 to 100° C. The reaction time is preferably 2 to 24 hours, more preferably 2 to 12 hours from the viewpoint of production efficiency.

[0109] The polymerization initiator may be added to the monomer solution and then fed to the reaction vessel, or an initiator solution may be prepared separately from the monomer solution and then fed to the reaction vessel independently. Since there is a possibility that the polymerization reaction proceeds due to radicals generated from the initiator during the waiting time, resulting in the formation of a super-polymer, it is preferable to prepare the monomer solution and the initiator solution independently and dropwise feed them from the viewpoint of quality control. The acid labile group introduced into the monomer may be used as is, or may be protected or partially protected after polymerization. In addition, a known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol may be used in combination to adjust the molecular weight. In this case, the amount of these chain transfer agents added is preferably 0.01 to 20 mol% based on the total amount of monomers to be polymerized.

[0110] When hydroxystyrene or hydroxyvinylnaphthalene is copolymerized, hydroxystyrene or hydroxyvinylnaphthalene may be polymerized by heating with another monomer in an organic solvent after adding a radical polymerization initiator, or acetoxystyrene or acetoxyvinylnaphthalene may be used and, after polymerization, the acetoxy group may be deprotected by alkaline hydrolysis to give polyhydroxystyrene or hydroxypolyvinylnaphthalene.

[0111] As the base for the alkaline hydrolysis, ammonia water, triethylamine, etc. can be used. The reaction temperature is preferably −20 to 100° C., more preferably 0 to 60° C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0112] The amount of each monomer in the monomer solution may be appropriately set so as to obtain the preferred content ratio of the repeating units described above.

[0113] The polymer obtained by the above-mentioned production method may be a reaction solution obtained by a polymerization reaction as a final product, or a powder obtained through a purification process such as a reprecipitation method in which a polymerization solution is added to a poor solvent to obtain a powder may be treated as a final product. However, from the viewpoint of work efficiency and quality stabilization, it is preferable to treat the polymer solution obtained by dissolving the powder obtained by the purification process in a solvent as a final product. Specific examples of the solvent to be used in this case include ketones such as cyclohexanone and methyl-2-n-pentyl ketone, alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol, ketoalcohols such as diacetone alcohol (DAA), propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, and propylene glycol. Examples of the solvent include ethers such as dimethyl ether and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono tert-butyl ether acetate; lactones such as GBL; high-boiling alcohol solvents such as diethylene glycol, propylene glycol, glycerin, 1,4-butanediol, and 1,3-butanediol; and mixed solvents thereof.

[0114] The concentration of the polymer in the polymer solution is preferably from 0.01 to 30% by mass, more preferably from 0.1 to 20% by mass.

[0115] The reaction solution or polymer solution is preferably filtered through a filter, which is effective in stabilizing the quality since it can remove foreign matter or gel that may cause defects.

[0116] The material of the filter used in the filter filtration includes fluorocarbon, cellulose, nylon, polyester, and hydrocarbon materials, but in the filtration process of the chemically amplified resist composition, a filter formed of a fluorocarbon, so-called Teflon (registered trademark), a hydrocarbon such as polyethylene or polypropylene, or nylon is preferred. The pore size of the filter can be appropriately selected according to the target cleanliness, but is preferably 100 nm or less, more preferably 20 nm or less. In addition, these filters may be used alone, or multiple filters may be used in combination. The filtration method may be to pass the solution through only once, but it is more preferable to circulate the solution and perform filtration multiple times. The filtration process can be performed in any order and number of times in the polymer production process, but it is preferable to filter the reaction solution after the polymerization reaction, the polymer solution, or both.

[0117] In the polymer P, the content of each repeating unit can be, for example, within the following ranges (mol %), but is not limited thereto. (I) one or more kinds of repeating units a are contained in an amount of 1 to 50%, preferably 5 to 40%, more preferably 5 to 30%, (II) one or more of the repeating units b1 or b2 is 30 to 99 mol %, more preferably 35 to 95 mol %, and still more preferably 40 to 90 mol %, (III) one or more of the repeating units c1 or c2, preferably 0 to 80 mol %, more preferably 5 to 70 mol %, and even more preferably 10 to 60 mol %, (IV) One or more repeating units derived from other monomers, preferably 0 to 80 mol %, more preferably 0 to 70 mol %, and even more preferably 0 to 50 mol %.

[0118] The polymer P may be used alone or in combination of two or more different polymers having different composition ratios, Mw and / or Mw / Mn. The base polymer (A) may contain a hydrogenated ring-opening metathesis polymer in addition to the polymer P, and the polymer described in JP-A-2003-66612 may be used.

[0119] [(B) Amine compound] The chemically amplified resist composition of the present invention contains (B) a quencher consisting of an amine compound represented by the following formula (1): In the present invention, the quencher refers to a material that traps the acid generated by the photoacid generator in the chemically amplified resist composition, thereby preventing the acid from diffusing into unexposed areas and forming a desired pattern. [ka]

[0120] In the formula (1), m is an integer of 0 to 10.

[0121] In formula (1), R N1 and R N2 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with halogen atoms, and -CH2- constituting the hydrocarbyl group may be substituted with -O- or -C(=O)-. N1 and R N2 may be bonded to each other to form a ring together with the nitrogen atom to which they are attached, and the ring may contain -O- or -S-. N1 and R N2 cannot simultaneously become a hydrogen atom.

[0122] R N1 and R N2The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl groups; cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl groups; cyclic unsaturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl groups; and groups obtained by combining these groups.

[0123] R N1 and R N2 The ring that may be formed by bonding to each other together with the nitrogen atom to which they are bonded is preferably an alicyclic ring, and examples thereof include, but are not limited to, an aziridine ring, an azetidine ring, a pyrrolidine ring, a piperidine ring, etc. In addition, -CH2- constituting these nitrogen-containing heterocycles may be substituted with -O- or -S-.

[0124] In formula (1), X L is a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. Specific examples thereof include, but are not limited to, those shown below. In the following formulas, * represents L a1 and represents a bond to a nitrogen atom. [ka]

[0125] [ka]

[0126] [ka]

[0127] Of these, X L -0~X L -22 and X L -47~X L -49 is preferred, X L -0~X L -17 is more preferred.

[0128] In formula (1), L a1 is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond. Among these, a single bond, an ether bond or an ester bond is preferred, and an ether bond or an ester bond is more preferred.

[0129] In formula (1), ring R R1 is a (m+1)-valent heterocyclic group having 2 to 20 carbon atoms and a lactone structure, lactam structure, sultone structure or sultam structure. The heterocyclic group may be either a single ring or a condensed ring, but is preferably a condensed ring from the viewpoints of raw material procurement and increasing the boiling point of the compound.

[0130] Specific examples of the heterocyclic group where m=0 include, but are not limited to, the groups shown below. In the following formula, * represents L a1 Represents a bond with . [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] In formula (1), R 11 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6 ]Cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as decanyl group, adamantyl group, and adamantylmethyl group; aryl groups having 6 to 20 carbon atoms, such as phenyl group, naphthyl group, and anthracenyl group; and groups obtained by combining these. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom, such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH2- constituting the hydrocarbyl group may be substituted with a group containing a heteroatom, such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a carbamate bond, an amide bond, an imide bond, a lactone ring, a sultone ring, a thiolactone ring, a lactam ring, a sultam ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0135] When m is 2 or more, R is 2 or more 11 may be the same or different, and there may be two or more R 11 are combined together to form R R1In this case, the ring may be formed together with the atoms forming R. Examples of the ring formed in this case include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, and an adamantane ring. R1 Two R's bonded to the same atom form 11 may be bonded to each other to form a ring, forming a spiro ring.

[0136] The amine compound represented by formula (1) is preferably one represented by the following formula (1A). [ka] (In the formula, m, L , L a1 , R R1 and R 11 is the same as above.)

[0137] In formula (1A), ring R R2 is an alicyclic hydrocarbon group having 3 to 20 carbon atoms formed together with the nitrogen atom in the formula, and -CH2- contained in the ring may be substituted with -O- or -S-. R2 is preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms in which --CH2-- contained in the ring is substituted with --O-- or --S--.

[0138] Examples of the amine compound represented by formula (1) include, but are not limited to, the following: [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] [ka]

[0149] [ka]

[0150] The amine compound represented by formula (1) can be produced, for example, according to the following scheme. [ka] (In the formula, R N1 , R N2 , m, X L , L a1 , RR1 and R 11 is the same as above. X hal is a chlorine atom, a bromine atom, or an iodine atom.

[0151] That is, the amine compound represented by formula (1) can be synthesized by a substitution reaction between an intermediate In-A, which can be synthesized by a known synthesis method, and a primary or secondary amine.

[0152] The synthesis can be carried out by a known organic synthesis method. Specifically, intermediate In-A is dissolved in a polar aprotic solvent such as acetone, acetonitrile, dimethylformamide, or dimethylsulfoxide, and a primary or secondary amine is added to carry out the reaction. hal When is a chlorine atom or a bromine atom, the reaction can be accelerated by adding a catalytic amount of an alkali metal iodide. Examples of the alkali metal iodide include sodium iodide and potassium iodide. The reaction temperature is preferably in the range from room temperature to the boiling point of the solvent used. The reaction time is usually about 30 minutes to 20 hours, although it is desirable to follow the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC) to complete the reaction in terms of yield. The amine compound represented by formula (1) can be obtained by carrying out a normal aqueous work-up from the reaction mixture. The obtained amine compound can be purified according to a normal method such as chromatography or recrystallization, if necessary.

[0153] The above-mentioned production method is merely an example, and the production method of the amine compound is not limited thereto.

[0154] In the chemically amplified resist composition of the present invention, the content of the quencher (B) consisting of an amine compound represented by formula (1) is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, relative to 80 parts by mass of the base polymer (A). If the content of the quencher (B) is within the above range, the sensitivity and resolution are good, and there is no risk of problems with foreign matter occurring after development of the resist film or during stripping, which is preferable. The quencher (B) may be used alone or in combination of two or more types.

[0155] The chemically amplified resist composition of the present invention is characterized by containing (A) polymer P and (B) an amine compound represented by formula (1), which realizes a chemically amplified resist composition with small LWR, excellent CDU, and high resolution. Although the reason for this is not clear, the following reasons are thought to be the case.

[0156] Polymer P has a structural portion incorporated therein that generates acid upon exposure. This significantly suppresses acid diffusion, improving LWR and CDU. Furthermore, the amine compound represented by formula (1) has a heterocyclic structural portion such as a highly polar lactone, lactam, sultone, or sultam. The highly polar heterocyclic structure increases the boiling point of the molecule, thereby suppressing the volatilization of the amine compound during the heating process after application of the resist composition.

[0157] Examples of high boiling point amine compounds include those having a long chain alkyl group and those having an aromatic group such as benzimidazole or 2,6-diisopropylaniline. However, in either case, the solubility in an alkaline developer is poor. Therefore, for example, when used as a positive resist composition for alkaline development, a poorly soluble portion is generated in the exposed area, causing a deterioration in resolution. On the other hand, since the amine compound represented by formula (1) has a high polarity structure, it not only has a high boiling point but also has excellent solubility in an alkaline developer, and can reliably dissolve the exposed area, thereby providing a chemically amplified resist composition with excellent resolution. On the other hand, since it is poorly soluble in an organic solvent, when it is applied as a negative resist composition for organic solvent development, it promotes the insolubilization of the exposed area. As a result, the contrast is increased and the resolution is improved, as in the case of a positive resist composition for alkaline development. Although the onium salt type quencher (for example, that described in International Publication No. 2008 / 066011) has a salt structure and therefore volatilization during baking is suppressed, the resolution is still insufficient from the viewpoint of developer solubility.

[0158] In this way, it is speculated that by combining polymer P, which can highly control acid diffusion, with an amine compound having a specific structure that contributes to improving resolution, it is possible to construct a chemically amplified resist composition that achieves significantly improved LWR, CDU, and resolution.

[0159] [(C) Organic solvent] The chemically amplified resist composition of the present invention may further contain an organic solvent (C). The organic solvent of component (C) is not particularly limited as long as it is capable of dissolving the above-mentioned and below-mentioned components. Examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketoalcohols such as DAA; PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monoethyl ether; and the like, as described in paragraphs

[0144] and

[0145] of JP-A-2008-111103. Examples of suitable solvents include ethers such as propylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono tert-butyl ether acetate; lactones such as GBL; and mixed solvents thereof. When an acetal-based acid labile group is used, a high-boiling alcohol solvent, specifically diethylene glycol, propylene glycol, glycerin, 1,4-butanediol, 1,3-butanediol, and the like, can also be added to accelerate the deprotection reaction of the acetal.

[0160] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA and mixed solvents thereof are preferred.

[0161] In the chemically amplified resist composition of the present invention, the content of the organic solvent (C) is preferably 200 to 5,000 parts by mass, and more preferably 400 to 3,000 parts by mass, relative to 80 parts by mass of the base polymer (A). The organic solvent (C) may be used alone or in combination of two or more kinds.

[0162] [(D) Photoacid generator] The chemically amplified resist composition of the present invention contains a photoacid generating site in the polymer P, and may further contain a photoacid generator (D) as an additive. The photoacid generator is not particularly limited as long as it is a compound that generates an acid upon irradiation with high energy rays. Suitable photoacid generators include photoacid generators such as sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxydicarboximide, O-arylsulfonyloximes, and O-alkylsulfonyloximes. Examples of these photoacid generators include those described in paragraphs

[0102] to

[0113] of JP 2007-145797 A.

[0163] As the photoacid generator, a sulfonium salt represented by the following formula (2) is also preferable. [ka]

[0164] In formula (2), R 101 ~R 103 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 101 , R 102 and R 103 Any two of R may be bonded to each other to form a ring together with the sulfur atom to which they are attached. 101 ~R 103 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R Z1 , R Z2 and R Z3 Examples of the hydrocarbyl group having 1 to 20 carbon atoms and optionally containing a heteroatom, represented by the following formula: In addition, examples of the cation of the sulfonium salt represented by formula (2) include the same as those exemplified as the sulfonium cation represented by formula (Z1).

[0165] In formula (2), Xa - is an anion selected from the following formulas (2A) to (2D). [ka]

[0166] In formula (2A), R fa is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. Examples of the anion represented by formula (2A) include a nonafluorobutanesulfonate anion, a partially fluorinated sulfonate anion described in paragraphs

[0247] to

[0251] of JP-A No. 2012-189977, a partially fluorinated sulfonate anion described in paragraphs

[0261] to

[0265] of JP-A No. 2013-101271, and a partially fluorinated sulfonate anion described in paragraphs

[0261] to

[0265] of JP-A No. 2013-101271.

[0167] As the anion represented by formula (2A), one represented by the following formula (2A') is particularly preferred. [ka]

[0168] In formula (2A'), R HF is a hydrogen atom or a trifluoromethyl group.

[0169] In formula (2A'), R 111 R is a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. 111 The heteroatom that may be contained in is preferably an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom, and more preferably an oxygen atom. The hydrocarbyl group is preferably one having 6 to 30 carbon atoms in order to obtain high resolution in fine pattern formation.

[0170] R 111The hydrocarbyl group having 1 to 30 carbon atoms and represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, a nonyl group, an undecyl group, a tridecyl group, a pentadecyl group, a heptadecyl group, and an icosyl group; a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-adamantylmethyl group, a norbornyl group, and a nonyl group. Examples of the alkyl group include cyclic saturated hydrocarbyl groups having 3 to 30 carbon atoms, such as a carboxymethyl group, a tricyclodecanyl group, a tetracyclododecanyl group, a tetracyclododecanylmethyl group, and a dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups having 2 to 30 carbon atoms, such as an allyl group and a 3-cyclohexenyl group; aryl groups having 6 to 30 carbon atoms, such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group; aralkyl groups having 7 to 30 carbon atoms, such as a benzyl group and a diphenylmethyl group; and groups obtained by combining these.

[0171] In addition, some or all of the hydrogen atoms of these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH2- constituting these groups may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of hydrocarbyl groups containing heteroatoms include tetrahydrofuryl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 5-hydroxy-1-adamantyl, 5-tert-butylcarbonyloxy-1-adamantyl, 4-oxatricyclo[4.2.1.0]phenyl, 4-phenylpropanediyl ... 3,7 ]nonane-5-one-2-yl group, 3-oxocyclohexyl group, and the like.

[0172] The synthesis of a sulfonium salt having an anion represented by formula (2A') is described in detail in JP-A-2007-145797, JP-A-2008-106045, JP-A-2009-7327, JP-A-2009-258695, and the like.

[0173] Examples of the anion represented by formula (2A) include, but are not limited to, those shown below: In the following formula, Ac is an acetyl group. [ka]

[0174] [ka]

[0175] [ka]

[0176] [ka]

[0177] In formula (2B), R fb1 and R fb2 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula R include the same as those exemplified above. fb1 and R fb2 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 are bonded to each other and the group to which they are bonded (-CF2-SO2-N - -SO2-CF2-) may form a ring, in which case, R fb1 and R fb2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0178] In formula (2C), R fc1 , R fc2 and R fc3 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 111 Examples of the hydrocarbyl group represented by the formula R include the same as those exemplified above. fc1 , R fc2 and R fc3 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2are bonded to each other and the groups to which they are bonded (-CF2-SO2-C - -SO2-CF2-) may form a ring, in which case, R fb1 and R fb2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0179] In formula (2D), R fd is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Hydrocarbyl The group is R 112 Examples of the above-mentioned examples are the same as those mentioned in the description of the above.

[0180] The synthesis of the sulfonium salt having the anion represented by formula (2D) is described in detail in JP-A-2010-215608.

[0181] Examples of the anion represented by formula (2D) include, but are not limited to, those shown below. [ka]

[0182] [ka]

[0183] Although the photoacid generator having the anion represented by formula (2D) does not have a fluorine atom at the α-position of the sulfo group, it has two trifluoromethyl groups at the β-position, and therefore has sufficient acidity to cleave the acid labile group in the base polymer, and can therefore be used as a photoacid generator.

[0184] As the photoacid generator (D), a compound represented by the following formula (3) is also preferred. [ka]

[0185] In formula (3), R 201 and R 202 R is each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 203 is a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. 201 , R 202 and R 203 Any two of these may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. G is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a hetero atom. L x is a divalent linking group.

[0186] R 201 and R 202 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl and 2-ethylhexyl groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, norbornyl, oxanorbornyl and tricyclo[5.2.1.0]. 2,6] cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms such as decanyl group and adamantyl group; aryl groups having 6 to 30 carbon atoms such as phenyl group and naphthyl group; and groups obtained by combining these. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH2- constituting the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like. Of these, R 201 and R 202 is preferably an aryl group in which a hydrogen atom may be substituted.

[0187] R 203The hydrocarbylene group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkanediyl groups having 1 to 20 carbon atoms, such as a methanediyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; a cyclopentanediyl group, and a cyclohexanediyl group. cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms, such as a norbornanediyl group or an adamantanediyl group; arylene groups having 6 to 20 carbon atoms, such as a phenylene group, a methylphenylene group, an ethylphenylene group, an n-propylphenylene group, an isopropylphenylene group, an n-butylphenylene group, an isobutylphenylene group, a sec-butylphenylene group, a tert-butylphenylene group, a naphthylene group, a methylnaphthylene group, an ethylnaphthylene group, an n-propylnaphthylene group, an isopropylnaphthylene group, an n-butylnaphthylene group, an isobutylnaphthylene group, a sec-butylnaphthylene group or a tert-butylnaphthylene group; and groups obtained by combining these. In addition, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- constituting the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbylene group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. 203 is preferably an aryl group in which a hydrogen atom may be substituted.

[0188] The hydrocarbylene group represented by G may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 203 Examples of the hydrocarbylene group represented by the formula (I) include the same as those exemplified above. In addition, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH2- constituting the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the hydrocarbylene group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like. Among these, G is preferably a methanediyl group or a methanediyl group in which a hydrogen atom is substituted with a fluorine atom or a trifluoromethyl group.

[0189] L x Examples of the divalent linking group represented by the formula (I) include an ether bond, an ester bond, a thioether bond, a sulfinic acid ester bond, a sulfonic acid ester bond, a carbonate bond, and a carbamate bond.

[0190] Examples of photoacid generators represented by formula (3) include those shown below, and include the same ones as those exemplified as photoacid generators represented by formula (3) in JP2018-062503A.

[0191] In the chemically amplified resist composition of the present invention, the content of the photoacid generator (D) is preferably 0 to 40 parts by mass, more preferably 0 to 20 parts by mass, relative to 80 parts by mass of the base polymer (A). If the content of the photoacid generator is within the above range, the resolution is good and there is no risk of problems with foreign matter occurring after resist development or during stripping, which is preferable. The photoacid generator (D) may be used alone or in combination of two or more kinds.

[0192] [(E) Other quenchers] The chemically amplified resist composition of the present invention may contain (E) a quencher other than the amine compound represented by formula (1) (hereinafter also referred to as "other quencher"). Examples of the other quencher of component (E) include onium salts represented by the following formula (4-1) or (4-2). [ka]

[0193] In formula (4-1), R 301 represents a hydrogen atom or a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom, except for those in which the hydrogen atom bonded to the carbon atom at the α-position of the sulfo group is substituted with a fluorine atom or a fluoroalkyl group.

[0194] R 301 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl and n-decyl groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorbornyl and tricyclo[5.2.1.0]. 2,6]Cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms, such as decanyl group and adamantyl group; aryl groups having 6 to 40 carbon atoms, such as phenyl group, naphthyl group and anthracenyl group; and groups obtained by combining these. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom, such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH2- constituting the hydrocarbyl group may be substituted with a group containing a heteroatom, such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0195] In formula (4-2), R 302 is a hydrogen atom or a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. 301 In addition to the specific examples of the substituents given above, examples thereof include fluorinated alkyl groups such as a trifluoromethyl group and a trifluoroethyl group, and fluorinated aryl groups such as a pentafluorophenyl group and a 4-trifluoromethylphenyl group.

[0196] Examples of the anion of the onium salt represented by formula (4-1) include, but are not limited to, those shown below. [ka]

[0197] [ka]

[0198] Examples of the anion of the onium salt represented by formula (4-2) include, but are not limited to, those shown below. [ka]

[0199] [ka]

[0200] In formulas (4-1) and (4-2), Mq + is an onium cation. The onium cation is preferably one represented by the following formula (4A), (4B) or (4C). [ka]

[0201] In formulas (4A) to (4C), R 311 ~R 319 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. 311 and R 312 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached, R 316 and R 317 and may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. Z1 , R Z2 and R Z3 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0202] Mq + Specific examples of the onium cation represented by the formula (I) include, but are not limited to, those shown below. [ka]

[0203] [ka]

[0204] [ka]

[0205] Specific examples of the onium salt represented by formula (4-1) or (4-2) include any combination of the above-mentioned anions and cations. These onium salts can be easily prepared by ion exchange reaction using known organic chemical methods. For ion exchange reaction, refer to, for example, JP-A-2007-145797.

[0206] The onium salt represented by formula (4-1) or (4-2) functions as a quencher in the chemically amplified resist composition of the present invention. This is because each counter anion of the onium salt is a conjugate base of a weak acid. The weak acid here means an acidity that cannot deprotect the acid labile group of the acid labile group-containing unit contained in the base polymer. The onium salt represented by formula (4-1) or (4-2) functions as a quencher when used in combination with an onium salt-type photoacid generator having a conjugate base of a strong acid such as a sulfonic acid whose α-position is fluorinated as a counter anion. That is, when an onium salt that generates a strong acid such as a sulfonic acid whose α-position is fluorinated and an onium salt that generates a weak acid such as a sulfonic acid or carboxylic acid that is not substituted with fluorine are mixed and used, when the strong acid generated from the photoacid generator by irradiation with high energy rays collides with an onium salt having an unreacted weak acid anion, the weak acid is released by salt exchange to generate an onium salt having a strong acid anion. In this process, the strong acid is exchanged for a weaker acid with a lower catalytic activity, and the acid appears to be deactivated, thereby enabling control of acid diffusion.

[0207] Here, when the photoacid generator that generates a strong acid is an onium salt, the strong acid generated by irradiation with high energy rays can be exchanged for a weak acid as described above, but on the other hand, it is considered that the weak acid generated by irradiation with high energy rays collides with the onium salt that generates the unreacted strong acid and is unlikely to undergo salt exchange. This is due to the phenomenon that the onium cation is more likely to form an ion pair with the anion of the strong acid.

[0208] When the onium salt represented by formula (4-1) or (4-2) is contained as the (E) other quencher, the content is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 80 parts by mass of the (A) base polymer. If the content of the onium salt is within the above range, the resolution is good and the sensitivity is not significantly reduced, which is preferable. The onium salt represented by formula (4-1) or (4-2) may be used alone or in combination of two or more kinds.

[0209] [(F) Surfactant] The chemically amplified resist composition of the present invention may further contain a surfactant (F). The surfactant of the component (F) is preferably a surfactant that is insoluble or poorly soluble in water and soluble in an alkaline developer, or a surfactant that is insoluble or poorly soluble in water and an alkaline developer. Examples of such surfactants include those described in JP-A-2010-215608 and JP-A-2011-16746.

[0210] Among the surfactants described in the above publication, preferred surfactants that are insoluble or poorly soluble in water and alkaline developers include FC-4430 (manufactured by 3M), Surflon (registered trademark) S-381 (manufactured by AGC Seimi Chemical Co., Ltd.), Olfine (registered trademark) E1004 (manufactured by Nissin Chemical Industry Co., Ltd.), KH-20, KH-30 (manufactured by AGC Seimi Chemical Co., Ltd.), and an oxetane ring-opening polymer represented by the following formula (surf-1): [ka]

[0211] Here, R, Rf, A, B, C, m, and n apply only to formula (surf-1), regardless of the above description. R is a divalent to tetravalent aliphatic group having 2 to 5 carbon atoms. Examples of the aliphatic group include divalent ones such as ethylene group, 1,4-butylene group, 1,2-propylene group, 2,2-dimethyl-1,3-propylene group, and 1,5-pentylene group, and examples of trivalent or tetravalent ones include the following: [ka] (In the formula, the dashed lines represent bonds and are partial structures derived from glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol, respectively.)

[0212] Among these, a 1,4-butylene group, a 2,2-dimethyl-1,3-propylene group, and the like are preferable.

[0213] Rf is a trifluoromethyl group or a pentafluoroethyl group, preferably a trifluoromethyl group. m is an integer of 0 to 3, n is an integer of 1 to 4, and the sum of n and m is the valence of R, which is an integer of 2 to 4. A is 1. B is an integer of 2 to 25, preferably an integer of 4 to 20. C is an integer of 0 to 10, preferably 0 or 1. The order of each constitutional unit in the formula (surf-1) is not specified, and they may be bonded in blocks or randomly. The production of a partially fluorinated oxetane ring-opening polymer surfactant is described in detail in the specification of U.S. Pat. No. 5,650,483.

[0214] A surfactant that is insoluble or poorly soluble in water and soluble in an alkaline developer has a function of reducing water penetration and leaching by being oriented on the surface of the resist film when a resist protective film is not used in ArF immersion lithography. Therefore, it is useful for suppressing the elution of water-soluble components from the resist film and reducing damage to the exposure device, and is also useful because it is soluble during alkaline aqueous solution development after exposure and PEB, and is unlikely to become a foreign matter that causes defects. Such surfactants are insoluble or poorly soluble in water and soluble in an alkaline developer, and are polymer-type surfactants, also called hydrophobic resins, and are particularly preferred for their high water repellency and improved water slipping properties.

[0215] Such polymeric surfactants include those containing at least one repeating unit selected from those represented by any of the following formulas (5A) to (5E). [ka]

[0216] In formulas (5A) to (5E), R D is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 1 R is -CH2-, -CH2CH2-, -O- or two -H separated from each other. s1 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms. s2 R is a single bond or a linear or branched hydrocarbylene group having 1 to 5 carbon atoms. s3 R are each independently a hydrogen atom, a hydrocarbyl group or a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, or an acid labile group. s3 When R is a hydrocarbyl group or a fluorinated hydrocarbyl group, an ether bond or a carbonyl group may be present between the carbon-carbon bonds. s4 is a (u+1)-valent hydrocarbon group or fluorinated hydrocarbon group having 1 to 20 carbon atoms. u is an integer of 1 to 3. s5 each independently represents a hydrogen atom or -C(=O)-OR s7 R is a group represented by the formula: s7 R is a fluorinated hydrocarbyl group having 1 to 20 carbon atoms. s6 is a hydrocarbyl group or a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, and an ether bond or a carbonyl group may be present between the carbon-carbon bonds.

[0217] R s1 The hydrocarbyl group represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclobutyl group, an n-pentyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an adamantyl group, a norbornyl group, etc. Among these, those having 1 to 6 carbon atoms are preferred.

[0218] R s2 The hydrocarbylene group represented by the formula (I) may be any of linear, branched, and cyclic, and specific examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group.

[0219] R s3 or R s6 The hydrocarbyl group represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include an alkyl group, an alkenyl group and an alkynyl group, with an alkyl group being preferred. s1 In addition to the examples of the hydrocarbyl group represented by the formula (I), examples of the hydrocarbyl group represented by the formula (I) include an n-undecyl group, an n-dodecyl group, a tridecyl group, a tetradecyl group, and a pentadecyl group. s3 or R s6 Examples of the fluorinated hydrocarbyl group represented by the formula (1) include groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbyl group described above have been substituted with fluorine atoms. As described above, an ether bond or a carbonyl group may be present between these carbon-carbon bonds.

[0220] R s3 Examples of the acid labile group represented by the formula (L1) to (L4) include the groups represented by the formulas (L1) to (L4) above, tertiary hydrocarbyl groups having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, trialkylsilyl groups in which each alkyl group has 1 to 6 carbon atoms, and oxoalkyl groups having 4 to 20 carbon atoms.

[0221] R s4 The (u+1)-valent hydrocarbon group or fluorinated hydrocarbon group represented by the formula (1) may be linear, branched, or cyclic, and specific examples thereof include groups obtained by further eliminating u hydrogen atoms from the above-mentioned hydrocarbyl group or fluorinated hydrocarbyl group.

[0222] R s7The fluorinated hydrocarbyl group represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include those in which some or all of the hydrogen atoms of the hydrocarbyl group have been substituted with fluorine atoms. Specific examples thereof include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoro-1-propyl group, a 3,3,3-trifluoro-2-propyl group, a 2,2,3,3-tetrafluoropropyl group, a 1,1,1 ,3,3,3-hexafluoroisopropyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl group, 2-(perfluorobutyl)ethyl group, 2-(perfluorohexyl)ethyl group, 2-(perfluorooctyl)ethyl group, and 2-(perfluorodecyl)ethyl group.

[0223] Examples of the repeating unit represented by any one of formulas (5A) to (5E) include, but are not limited to, those shown below. In the following formula, R D is the same as above. [ka]

[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227] [ka]

[0228] The polymer surfactant may further contain other repeating units than the repeating units represented by formulae (5A) to (5E). Examples of the other repeating units include repeating units obtained from methacrylic acid and α-trifluoromethylacrylic acid derivatives. In the polymer surfactant, the content of the repeating units represented by formulae (5A) to (5E) in the total repeating units is preferably 20 mol % or more, more preferably 60 mol % or more, and even more preferably 100 mol %.

[0229] The Mw of the polymer surfactant is preferably from 1,000 to 500,000, and more preferably from 3,000 to 100,000. The Mw / Mn is preferably from 1.0 to 2.0, and more preferably from 1.0 to 1.6.

[0230] The method for synthesizing the polymeric surfactant includes a method in which a monomer containing an unsaturated bond that gives the repeating units represented by formulas (5A) to (5E) and other repeating units as necessary is heated in an organic solvent with the addition of a radical initiator to polymerize. Examples of the organic solvent used during polymerization include toluene, benzene, THF, diethyl ether, and dioxane. Examples of the polymerization initiator include AIBN, 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. The reaction temperature is preferably 50 to 100°C. The reaction time is preferably 4 to 24 hours. The acid labile group introduced into the monomer may be used as it is, or may be protected or partially protected after polymerization.

[0231] When synthesizing the polymeric surfactant, a known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol may be used to adjust the molecular weight. In this case, the amount of the chain transfer agent added is preferably 0.01 to 10 mol% based on the total moles of the monomers to be polymerized.

[0232] When the chemically amplified resist composition of the present invention contains a surfactant (F), the content is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 80 parts by mass of the base polymer (A). If the surfactant (F) content is 0.1 part by mass or more, the receding contact angle between the resist film surface and water is sufficiently improved, and if it is 50 parts by mass or less, the dissolution rate of the resist film surface in the developer is low, and the height of the formed fine pattern is sufficiently maintained. The surfactant (F) may be used alone or in combination of two or more kinds.

[0233] [Pattern formation method] The pattern forming method of the present invention includes the steps of forming a resist film on a substrate using the above-mentioned chemically amplified resist composition, exposing the resist film to KrF excimer laser light, ArF excimer laser light, EB or EUV, and developing the exposed resist film using a developer.

[0234] The substrate may be, for example, a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0235] The resist film can be formed, for example, by applying the chemically amplified resist composition by a method such as spin coating to a film thickness of 0.05 to 2 μm, and then pre-baking this on a hot plate, preferably at 60 to 150° C. for 1 to 10 minutes, more preferably at 80 to 140° C. for 1 to 5 minutes.

[0236] When KrF excimer laser light, ArF excimer laser light, or EUV is used for exposing the resist film, a mask for forming a desired pattern is used, and the exposure amount is preferably 1 to 200 mJ / cm. 2 , more preferably 10 to 100 mJ / cm 2When EB is used, the exposure dose is preferably 1 to 300 μC / cm 2 , either directly or through a mask for forming a desired pattern. 2 , more preferably 10 to 200 μC / cm 2 Irradiate so that

[0237] In addition to the usual exposure method, the immersion method can be used in which a liquid with a refractive index of 1.0 or more is placed between the resist film and the projection lens. In this case, a water-insoluble protective film can also be used.

[0238] The water-insoluble protective film is used to prevent elution from the resist film and to increase the water sliding property of the film surface, and is roughly divided into two types. One is an organic solvent stripping type that needs to be stripped before alkaline aqueous solution development by an organic solvent that does not dissolve the resist film, and the other is an alkaline aqueous solution soluble type that is soluble in an alkaline developer and removes the protective film together with removing the soluble part of the resist film. The latter is based on a polymer having a 1,1,1,3,3,3-hexafluoro-2-propanol residue that is insoluble in water and soluble in an alkaline developer, and is preferably a material dissolved in an alcohol-based solvent having 4 or more carbon atoms, an ether-based solvent having 8 to 12 carbon atoms, or a mixed solvent thereof. The above-mentioned water-insoluble and alkaline developer-soluble surfactant can also be dissolved in an alcohol-based solvent having 4 or more carbon atoms, an ether-based solvent having 8 to 12 carbon atoms, or a mixed solvent thereof.

[0239] After the exposure, PEB may be performed, for example, by heating on a hot plate at preferably 60 to 150° C. for 1 to 5 minutes, more preferably 80 to 140° C. for 1 to 3 minutes.

[0240] Development can be carried out, for example, using a developer of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of preferably 0.1 to 5 mass %, more preferably 2 to 3 mass %, for preferably 0.1 to 3 minutes, more preferably 0.5 to 2 minutes, by a conventional method such as a dip method, a puddle method, a spray method, etc. The exposed area dissolves by development, and a target pattern is formed on the substrate.

[0241] As a means for forming a pattern, after forming a resist film, a pure water rinse (post soak) may be performed to extract an acid generator and the like from the film surface or to wash away particles, or a rinse (post soak) may be performed to remove water remaining on the film after exposure.

[0242] Furthermore, the pattern may be formed by a double patterning method. Examples of the double patterning method include a trench method in which a 1:3 trench pattern is processed by a first exposure and etching, and a 1:3 trench pattern is formed by a second exposure with a shifted position to form a 1:1 pattern, and a line method in which a first base with a 1:3 isolated leave pattern is processed by a first exposure and etching, and a second base with a 1:3 isolated leave pattern formed under the first base is processed by a second exposure with a shifted position to form a 1:1 pattern with half the pitch.

[0243] In the pattern forming method of the present invention, negative tone development can also be carried out by using an organic solvent as the developer instead of the alkaline aqueous solution to dissolve the unexposed areas.

[0244] The organic solvent development may be carried out using the following developing solutions: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, propyl cyclohexanone ... Examples of the organic solvent that can be used include methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents may be used alone or in combination of two or more. EXAMPLES

[0245] The present invention will be specifically described below with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. The apparatuses used are as follows. IR: Thermo Fisher Scientific NICOLET 6700 · 1 H-NMR: ECA-500 manufactured by JEOL Ltd.

[0246] [1] Synthesis of amine compounds [Synthesis Example 1-1] Synthesis of Q-1 (1) Synthesis of intermediate In-1 [ka]

[0247] In a nitrogen atmosphere, raw material M-1 (61.7 g) and chloroacetyl chloride (54.2 g) were dissolved in THF (400 g) in a reaction vessel. The reaction system was cooled to below 10°C, and a solution consisting of pyridine (37.3 g) and THF (40 g) was added. After the dropwise addition, the mixture was aged for 12 hours at an internal temperature of 20°C. After the aging, the reaction system was cooled, and saturated sodium bicarbonate water (440 g) was added dropwise to stop the reaction. Then, diisopropyl ether (880 g) was added to perform crystallization, and the precipitated crystals were filtered and dried under reduced pressure to obtain intermediate In-1 as white crystals (yield 91.1 g, 99%).

[0248] (2) Synthesis of Q-1 [ka] Under a nitrogen atmosphere, intermediate In-1 (91.1 g), sodium iodide (6.0 g), and acetone (320 g) were charged into a reaction vessel, and morpholine (41.8 g) was added dropwise at room temperature. After the dropwise addition, the mixture was aged for 24 hours while heating under reflux. After confirming the disappearance of intermediate In-1 by TLC, the reaction solution was cooled to room temperature, and the reaction was stopped with saturated sodium bicarbonate water (160 g). Then, acetone was distilled off using an evaporator. After distillation, methylene chloride (480 g) was added to extract the target product and the liquids were separated. The obtained organic layer was washed four times with water (160 g) and once with saturated saline (160 g). The organic layer was separated and concentrated, and the residue was purified using a silica gel column to obtain Q-1 as an oil (yield 91.3 g, 71%).

[0249] The IR spectrum data of Q-1 is shown below. The nuclear magnetic resonance spectrum ( 1 H-NMR / DMSO-d6) is shown in Figure 1. IR(D-ATR): ν= 2988, 2973, 2941, 2892, 2863, 2800, 2694, 1781, 1743, 1451, 1412, 1402, 1360, 1339, 1301, 1292, 1277, 1240, 1208, 1196, 1183, 1169, 1121, 1101, 1070, 1041, 1020, 1009, 994, 959, 905, 891, 867, 837, 809, 789, 737, 715, 643, 589, 549, 484, 436 cm -1 .

[0250] [Synthesis Example 1-2] Synthesis of Q-2 [ka]

[0251] Q-2 was synthesized (yield: 11.9 g, 70%) in the same manner as in Synthesis Example 1-1, except that raw material M-1 was changed to raw material M-2.

[0252] The IR spectrum data of Q-2 is shown below. The nuclear magnetic resonance spectrum ( 1 H-NMR / DMSO-d6) is shown in Figure 2. IR(D-ATR): ν= 3029, 2980, 2935, 2907, 2860, 2843 2751, 2684, 1786, 1745, 1460, 1445, 1413, 1375, 1360, 1339, 1328, 1320, 1296, 1278, 1244, 1234, 1191, 1180, 1159, 1146, 1112, 1071, 1045, 1037, 1026, 990, 963, 935, 905, 898, 873, 862, 855, 807, 740, 704, 651, 639, 584, 522, 446, 438 cm -1 .

[0253] [Synthesis Example 1-3] Synthesis of Q-3 [ka]

[0254] Q-3 was synthesized (yield: 23.3 g, 90%) in the same manner as in Synthesis Example 1-1, except that raw material M-1 was changed to raw material M-3.

[0255] The IR spectrum data of Q-3 is shown below. The nuclear magnetic resonance spectrum ( 1 H-NMR / DMSO-d6) is shown in Figure 3. IR(D-ATR): ν= 2967, 2932, 2854, 2696, 2432, 1789, 1775, 1765, 1642, 1453, 1426, 1404, 1375, 1333, 1300, 1279, 1230, 1205, 1181, 1162, 1116, 1073, 1036, 1013, 999, 960, 918, 891, 868, 814, 709, 662, 632, 589, 548, 515, 459 cm -1 .

[0256] [2] Synthesis of base polymer The base polymer used in the chemically amplified resist composition was synthesized by the method described below. The Mw of the resulting polymer was measured in terms of polystyrene by GPC using THF as the solvent.

[0257] [Synthesis Example 2-1] Synthesis of Polymer P-1 Under a nitrogen atmosphere, 2.8 g of triphenylsulfonium 1,1,3,3,3-pentafluoro-2-methacryloyloxypropane-1-sulfonate and 3-ethyl-3-exo-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecyl 12.3g, 4,8-dioxatricyclo[4.2.1.0 3,79.0 g of 5-nonan-2-yl, 2.4 g of 3-hydroxy-1-adamantyl methacrylate, and 0.9 g of dimethyl 2,2'-azobis(isobutyrate) were dissolved in 72.8 g of methyl ethyl ketone to prepare a solution. The solution was added dropwise to 20.7 g of methyl ethyl ketone stirred at 80° C. under a nitrogen atmosphere over 4 hours. After the addition was completed, the mixture was stirred for 2 hours while maintaining the temperature at 80° C., and then cooled to room temperature, and the polymerization solution was added dropwise to 400 g of hexane. The precipitated solid was filtered and washed twice with a mixed solvent of 45 g of methyl ethyl ketone and 195 g of hexane, and then vacuum dried at 50° C. for 20 hours to obtain a white powdery polymer P-1. The yield was 25.2 g, and the yield was 95%. When analyzed by GPC, the Mw of the polymer P-1 was 8,200 and the Mw / Mn was 1.58. [ka]

[0258] [Synthesis Examples 2-2 to 2-6] Synthesis of Polymers P-2 to P-6 Polymers P-2 to P-6 were synthesized in the same manner as in Synthesis Example 2-1, except that the types and mixing ratios of the monomers were changed. The types and introduction ratios of the repeating units of polymers P-1 to P-6 are shown in Table 1 below.

[0259] [Table 1]

[0260] In Table 1, the repeating units are as follows. [ka]

[0261] [3] Preparation of chemically amplified resist composition [Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-8] The amine compounds (Q-1 to Q-3), comparative quenchers (QA to QF), base polymers (P-1 to P-6), photoacid generator (PAG-X) and alkali-soluble surfactant (SF-1) were dissolved in a solvent containing 0.01 mass % of surfactant A (Omnova) in the compositions shown in Table 2 below to prepare solutions, which were then filtered through a 0.2 μm Teflon (registered trademark) type filter to prepare chemically amplified resist compositions (R-01 to R-24).

[0262] [Table 2]

[0263] In Table 2, the solvent, alkali-soluble surfactant SF-1, photoacid generator PAG-X, and comparative quenchers QA to QF are as follows. Solvent: PGMEA (propylene glycol monomethyl ether acetate) GBL (γ-butyrolactone)

[0264] Alkaline-soluble surfactant SF-1: Poly(2,2,3,3,4,4,4-heptafluoro-1-isobutyl-1-butyl methacrylate)-9-(2,2,2-trifluoro-1-trifluoromethylethyloxycarbonyl)-4-oxatricyclo[4.2.1.0 3,7 ]nonane-5-on-2-yl) [ka] Mw=7,700, Mw / Mn=1.82

[0265] Photoacid generator: PAG-X [ka]

[0266] Comparison quencher: QA~QF [ka]

[0267] Surfactant A: 3-methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane-tetrahydrofuran-2,2-dimethyl-1,3-propanediol copolymer (Omnova) [ka] a:(b+b'):(c+c')=1:4-7:0.01-1 (molar ratio) Mw=1,500

[0268] [4] Evaluation of chemically amplified resist compositions: ArF lithography evaluation [Examples 2-1 to 2-4, Comparative Examples 2-1 to 2-3] Each chemically amplified resist composition (R-01 to R-03, R-13, R-17 to R-19) was spin-coated onto a silicon wafer and a trilayer process substrate having a 200 nm-thick spin-on carbon film ODL-50 (carbon content: 80% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. and a 35 nm-thick silicon-containing spin-on hard mask SHB-A940 (silicon content: 43% by mass) formed thereon. The substrate was then baked at 100°C for 60 seconds using a hot plate to produce a 90 nm-thick resist film. This was subjected to immersion exposure through a mask using an ArF excimer laser immersion scanner (Nikon Corporation, NSR-610C, NA 1.30, σ 0.98 / 0.74, dipole aperture 90 degrees, s-polarized illumination) while changing the exposure dose. Water was used as the immersion liquid. It was then baked (PEB) for 60 seconds at the temperature shown in Table 3 below. After PEB, it was developed using butyl acetate for 30 seconds and then rinsed with diisoamyl ether. The mask was a halftone phase shift mask with a transmittance of 6%, and the design on the mask had a pattern of 45 nm lines / 90 nm pitch (actual dimensions on the mask were 4 times larger due to 1 / 4 reduced projection exposure). The dimensions of the trench pattern formed in the light shielding portion were observed with a critical dimension SEM (CG-4000) manufactured by Hitachi High-Technologies Corporation, and the sensitivity, LWR, and collapse limit were evaluated according to the following methods. The results are shown in Table 3.

[0269] [Sensitivity evaluation] The optimum exposure dose (Eop, mJ / cm) for the trench width dimension of 45 nm 2 ) was calculated and used as the sensitivity.

[0270] [LWR rating] In the trench pattern obtained by irradiation at Eop, the trench width was measured in a 200 nm range with 10 nm intervals, and the triple value (3σ) of the standard deviation (σ) was calculated as LWR (nm). The smaller this value, the smaller the roughness and the more uniform the space width pattern.

[0271] [Collapse limit evaluation] By reducing the exposure dose, the trench dimensions are enlarged and the line dimensions are reduced, but the maximum trench width at which the lines do not collapse is determined and taken as the collapse limit (nm). The larger the value, the higher the collapse resistance, which is preferable.

[0272] [Table 3]

[0273] The results shown in Table 3 indicate that the chemically amplified resist composition of the present invention has good sensitivity and is also excellent in LWR and collapse limit, demonstrating that the chemically amplified resist composition of the present invention is suitable as a material for ArF immersion lithography.

[0274] [5] Evaluation of chemically amplified resist compositions: EUV lithography evaluation (1) [Examples 3-1 to 3-12, Comparative Examples 3-1 to 3-5] Each chemically amplified resist composition (R-04 to R-12, R-14 to R-16, R-20 to R-24) was spin-coated on a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. was formed to a thickness of 20 nm, and the substrate was pre-baked at 100°C for 60 seconds using a hot plate to produce a resist film with a thickness of 40 nm. A 22 nm line and space (LS) 1:1 pattern was exposed using an EUV scanner NXE3300 (NA 0.33, σ 0.9, 90-degree dipole illumination) manufactured by ASML, and then PEB was performed on a hot plate for 60 seconds at the temperature listed in Table 4 below, and development was performed for 30 seconds with a 2.38% by mass TMAH aqueous solution to form a pattern.

[0275] The formed LS pattern was observed with a critical dimension SEM (CG-5000) manufactured by Hitachi High-Tech Corp., and the sensitivity, LWR and limiting resolution were evaluated according to the following methods. The results are shown in Table 4.

[0276] [Sensitivity evaluation] The optimal exposure dose Eop (mJ / cm) for obtaining an LS pattern with a space width of 22 nm and a pitch of 44 nm 2 ) was calculated and used as the sensitivity.

[0277] [LWR rating] For the LS pattern obtained by irradiation at Eop, the dimensions were measured at 10 points in the longitudinal direction of the space width, and the three times standard deviation (σ) (3σ) was calculated from the results, and this was taken as LWR. The smaller this value, the smaller the roughness and the more uniform the space width pattern that can be obtained.

[0278] [Limiting resolution evaluation] The minimum line width (nm) of the LS pattern separated at Eop was defined as the limiting resolution.

[0279] [Table 4]

[0280] The results shown in Table 4 demonstrate that the chemically amplified resist composition of the present invention exhibits good sensitivity, excellent limiting resolution, and excellent LWR in the formation of an LS pattern by EUV lithography.

[0281] [6] Evaluation of chemically amplified resist compositions: EUV lithography evaluation (2) [Examples 4-1 to 4-12, Comparative Examples 4-1 to 4-5] Each chemically amplified resist composition (R-04 to R-12, R-14 to R-16, R-20 to R-24) was spin-coated on a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. was formed to a thickness of 20 nm, and the resist film was pre-baked for 60 seconds at 105°C using a hot plate to produce a resist film with a thickness of 50 nm. This was exposed using an EUV scanner NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, a hole pattern mask with a pitch of 40 nm on the wafer and a +20% bias), and PEB was performed on a hot plate at the temperature shown in Table 5 below for 60 seconds, and development was performed for 30 seconds with a 2.38% by mass TMAH aqueous solution to obtain a hole pattern.

[0282] The formed hole pattern was observed with a critical dimension SEM (CG-6300) manufactured by Hitachi High-Tech Corp., and the sensitivity and CDU were evaluated according to the following methods. The results are shown in Table 5.

[0283] [Sensitivity evaluation] The optimal exposure dose Eop (mJ / cm) for obtaining a hole pattern with a dimension of 40 nm 2 ) was calculated and used as the sensitivity.

[0284] [CDU Rating] The dimensions of 50 hole patterns obtained by irradiation at Eop were measured, and the three times standard deviation (σ) (3σ) was calculated from the results and used as CDU. The smaller this value, the better the dimensional uniformity of the hole pattern.

[0285] [Table 5]

[0286] The results shown in Table 5 demonstrate that the chemically amplified resist composition of the present invention has good sensitivity and excellent CDU in the formation of a hole pattern by EUV lithography.

Claims

1. A chemically amplified resist composition comprising: (A) a base polymer; and (B) a quencher comprising an amine compound represented by the following formula (1): The chemically amplified resist composition comprises a polymer P, the base polymer including a repeating unit a having a structural moiety that decomposes upon irradiation with KrF excimer laser light, ArF excimer laser light, an electron beam, or extreme ultraviolet light to generate an acid, the repeating unit a being represented by the following formula (a1), (a2), or (a3): 【Chemistry 1】 (In the formula, m is an integer from 0 to 10. R N1 and R N2 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with halogen atoms, and —CH 2 - may be replaced by -O- or -C(=O)-. N1 and R N2 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and the ring may contain -O- or -S-. N1 and R N2 cannot simultaneously become a hydrogen atom. X L is a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. L a1 is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond. Ring R R1 is a (m+1)-valent heterocyclic group having 2 to 20 carbon atoms and having a lactone structure, lactam structure, sultone structure or sultam structure. R 11 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. When m is 2 or more, each R 11 may be the same or different, and there may be two or more R 11 are bonded to each other and bonded to R R1 It may form a ring together with the above atoms.) 【Chemistry 2】 (In the formula, R A is a hydrogen atom or a methyl group. R B is a hydrogen atom, a methyl group or a trifluoromethyl group. X 1 is a phenylene group or a naphthylene group. X 2 is --O-- or --N(H)--. Y L is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. R f1 and R f2 each independently represent a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms. n is an integer from 0 to 3. Za + is an onium cation. 【Chemistry 3】 (In the formula, R C is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. L is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Af is a hydrogen atom or a trifluoromethyl group. k is 0 or 1, provided that k is 0 when L is a single bond. Zb + is an onium cation.

2. R N1 and R N2 2. The chemically amplified resist composition according to claim 1, wherein the ring formed by bonding together with the nitrogen atom to which they are bonded may contain --O--.

3. 3. The chemically amplified resist composition according to claim 1, wherein the polymer P further comprises a repeating unit represented by the following formula (b1) or (b2): 【Chemistry 4】 (In the formula, R C each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y 1 is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-O-Y 11 - and Y 11 is an alkanediyl group having 1 to 10 carbon atoms which may contain a hydroxy group, an ether bond, an ester bond or a lactone ring, or a phenylene group or naphthylene group. Y 2 is a single bond or *-C(=O)-O-. * indicates a bond to a carbon atom in the main chain. A.L. 1 and A.L. 2 are each independently an acid labile group. R 1 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. a is an integer from 0 to 4.

4. 4. The chemically amplified resist composition according to claim 1, wherein the polymer P further comprises a repeating unit represented by the following formula (c1) or (c2): 【Chemistry 5】 (In the formula, R C each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A p is a hydrogen atom, or a polar group containing at least one structure selected from a hydroxy group, a cyano group, a carbonyl group, a carboxy group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (-C(=O)-O-C(=O)-). Y 3 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. R 2 represents a halogen atom, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylcarbonyl group having 2 to 20 carbon atoms which may contain a heteroatom. b is an integer from 1 to 4. c is an integer from 0 to 4, provided that 1≦b+c≦5.

5. The chemically amplified resist composition according to any one of claims 1 to 4, further comprising a photoacid generator.

6. 6. The chemically amplified resist composition according to claim 1, further comprising a quencher other than the amine compound represented by formula (1).

7. 7. The chemically amplified resist composition according to claim 1, further comprising a surfactant.

8. A pattern forming method comprising the steps of: forming a resist film on a substrate using the chemically amplified resist composition according to any one of claims 1 to 7; exposing the resist film to KrF excimer laser light, ArF excimer laser light, an electron beam or extreme ultraviolet light; and developing the exposed resist film using a developer.

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