Amine compound, chemically amplified resist composition, and pattern forming method

Abstract

To provide a chemically amplified resist composition having high sensitivity for both positive and negative types, capable of improving LWR and CDU, a quencher used in the chemically amplified resist composition, and a patterning method using the chemically amplified resist composition.SOLUTION: The present invention provides an amine compound represented by the formula (1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an amine compound, 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 increasingly miniaturized. In particular, the expansion of the logic memory market due to the spread of smartphones is driving miniaturization. The most advanced miniaturization technology is mass production of 10nm node devices using double patterning with ArF immersion lithography, and preparations are underway for mass production of the 7nm node, also using double patterning, for the next generation. Extreme ultraviolet (EUV) lithography is a candidate for the next-generation 5nm node.

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

[0004] As miniaturization progresses and approaches the diffraction limit of light, the optical contrast decreases. This decrease in optical contrast leads to a decrease in the resolution of hole and trench patterns and a decrease in focus margin in positive resist films. While thickening resist films would restore the thickness of resist films used in previous generation devices, it requires even higher dimensional uniformity (CDU), which cannot be achieved with previous photoresist compositions. To prevent a decrease in resist pattern resolution due to the decrease in optical contrast 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, which contain an acid generator and generate acid upon irradiation with light or an electron beam (EB) to cause an acid-induced deprotection reaction, and for chemically amplified negative resist compositions, which cause an acid-induced polarity change reaction or crosslinking reaction, the addition of a quencher (acid diffusion controller) to control the diffusion of acid into unexposed areas and improve contrast has been very effective. For this reason, many amine quenchers have been proposed (Patent Documents 1 and 2).

[0006] The acid-labile groups used in (meth)acrylate polymers for ArF resist compositions undergo deprotection using a photoacid generator that generates sulfonic acid substituted with a fluorine atom at the α-position, but not with an acid generator that generates sulfonic acid or carboxylic acid not substituted with a fluorine atom at the α-position. When a sulfonium salt or iodonium salt that generates sulfonic acid substituted with a fluorine atom at the α-position is mixed with a sulfonium salt or iodonium salt that generates sulfonic acid not substituted with a fluorine atom at the α-position, the sulfonium salt or iodonium salt that generates 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 substituted with a fluorine atom at the α-position generated by light reverts to the sulfonium salt or iodonium salt through ion exchange, and 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 has been proposed that uses a sulfonium salt or iodonium salt that generates a carboxylic acid as a quencher (Patent Document 3).

[0007] Sulfonium salt-type and iodonium salt-type quenchers are photodegradable, similar to photoacid generators. This means that the amount of quencher decreases in exposed areas. Because acid is generated in exposed areas, reducing the amount of quencher increases the relative acid concentration, thereby improving contrast. However, acid diffusion in exposed areas cannot be suppressed, making acid diffusion control difficult. It has also been pointed out that quencher aggregation reduces the CDU of the resist pattern.

[0008] Sulfonium salt-type and iodonium salt-type quenchers absorb light with a wavelength of 193 nm, and therefore, when used in combination with sulfonium salt-type and iodonium salt-type acid generators, the transmittance of the resist film to this light decreases. As a result, the cross-sectional shape of the developed pattern becomes tapered, particularly in resist films with a thickness of 100 nm or more. A highly transparent quencher is required for resist films with a thickness of 100 nm or more, particularly 150 nm or more.

[0009] Lowering the post-exposure bake (PEB) temperature is effective in suppressing acid diffusion. However, this reduces dissolution contrast, which in turn leads to degradation of resolution and line edge roughness (LWR). A new concept resist composition that suppresses acid diffusion and achieves high contrast is needed. It is also necessary to improve the dimensional uniformity of the developed pattern by preventing aggregation of the quencher in the resist film and homogenizing its distribution.

[0010] Amine quenchers that undergo polarity change due to acid catalysts have been proposed. Patent documents 4 and 5 propose amine quenchers with acid-labile groups. These quenchers generate carboxylic acids through acid-induced deprotection of tertiary esters with a carbonyl group on the nitrogen atom side, improving alkali solubility. However, in this case, the molecular weight on the nitrogen atom side cannot be increased, resulting in low acid diffusion control ability and minimal contrast improvement. Patent document 6 proposes a quencher that generates an amino group through acid-induced deprotection of a tert-butoxycarbonyl group. This mechanism generates the quencher upon exposure, which has the opposite effect of enhancing contrast. Contrast is improved by a mechanism in which the quencher disappears or the quenching ability decreases upon exposure or acid exposure. Patent document 7 proposes a quencher in which an amine compound forms a ring with an acid to form a lactam structure. The strong-basic amine compound converts to a weak-basic lactam compound, changing the acid activity and improving contrast. Although the application of these amine quenchers has been confirmed to improve performance to a certain extent, it is still insufficient to achieve a high level of control over acid diffusion, and the development of quenchers with even better acid diffusion control capabilities is desired. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 3751518 [Patent Document 2] Patent No. 4320520 [Patent Document 3] International Publication No. 2008 / 066011 [Patent Document 4] Patent No. 4044741 [Patent Document 5] Japanese Patent Application Laid-Open No. 2012-008550 [Patent Document 6] Patent No. 3790649 [Patent Document 7] Patent No. 5617799 Summary of the Invention [Problem to be solved by the invention]

[0012] In acid-catalyzed chemically amplified resist compositions, it is desirable to develop a quencher that can improve the LWR of line patterns and the CDU of hole patterns while also improving sensitivity. To achieve this, it is necessary to further reduce the diffusion distance of the acid and simultaneously improve contrast, which are contradictory properties that need to be improved.

[0013] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a chemically amplified resist composition that has high sensitivity and can improve LWR and CDU, whether it is a positive or negative resist composition, a quencher for use in the chemically amplified resist composition, and a pattern formation method that uses the chemically amplified resist composition. [Means for solving the problem]

[0014] There has been a need for the development of an amine quencher that has good sensitivity, adequately controlled acid diffusion, excellent solvent solubility, and is effective in suppressing pattern collapse.

[0015] As a result of extensive research to achieve the above object, the present inventors have found that by using an amine compound having a specific structure as a quencher, it is possible to obtain a chemically amplified resist composition which improves LWR and CDU, provides high contrast, excellent resolution, a wide process margin, and further suppresses swelling during development, making it extremely effective for precise microfabrication, and thus completed the present invention.

[0016] That is, the present invention provides the following amine compound, chemically amplified resist composition, and pattern forming method. 1. An amine compound represented by the following formula (1): [ka] (In the formula, n1 is an integer of 0 or 1. n2 is an integer of 1 to 3. n3 is an integer of 1 to 4. n4 is an integer of 0 to 4. However, when n1=0, n2+n3+n4≦5, and when n1=1, n2+n3+n4≦7. n5 is an integer of 1 to 3. R AL is an acid labile group formed with the adjacent oxygen atom. R F is a fluorine atom, a fluorine atom-containing saturated hydrocarbyl group having 1 to 6 carbon atoms, a fluorine atom-containing saturated hydrocarbyloxy group having 1 to 6 carbon atoms, or a fluorine atom-containing saturated hydrocarbylthio group having 1 to 6 carbon atoms. When n3≧2, each R F may be the same as or different from each other. R F and -OR AL are attached to adjacent carbon atoms. R 1 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. L A is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond. X L is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom. R N1 is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with halogen atoms, and -CH2- of the hydrocarbyl group may be substituted with -O- or -C(=O)-. N1 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 cannot be hydrogen atoms at the same time.) 2.R AL is a group represented by the following formula (AL-1) or (AL-2): [ka] (In the formula, R 2 , R 3 and R 4 are each independently a hydrocarbyl group having 1 to 12 carbon atoms, in which some of the -CH2- groups in the hydrocarbyl group may be substituted with -O- or -S-, and when the hydrocarbyl group contains an aromatic ring, some or all of the hydrogen atoms in the aromatic ring may be substituted with a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms which may contain a halogen atom, or an alkoxy group having 1 to 4 carbon atoms which may contain a halogen atom. 2 and R 3 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and some of the -CH2- in the ring may be substituted with -O- or -S-. R 5 and R 6 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms. 7 is a hydrocarbyl group having 1 to 20 carbon atoms, and —CH2— in the hydrocarbyl group may be substituted with —O— or —S—. 6 and R 7 and are bonded to each other and the carbon atom and L B may form a heterocyclic group having 3 to 20 carbon atoms together, and some of the -CH2- groups contained in the heterocyclic group may be substituted with -O- or -S-. L B is —O— or —S—. m1 is 0 or 1. m2 is 0 or 1. * represents a bond to the adjacent -O-.) 3. An amine compound of 1 or 2, which is represented by the following formula (1A): [ka] (In the formula, R AL , R F , R 1 , R N1 , X L and n1 to n5 are the same as above.) 4. The amine compound of 3, which is represented by the following formula (1B): [ka] (In the formula, R AL , R F , R 1 , X L and n1 to n4 are the same as above. Ring R N2 represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms formed together with the nitrogen atom in the formula, and one —CH2— contained in the ring may be substituted with —O— or —S—. 5. A chemically amplified resist composition containing a quencher consisting of an amine compound according to any one of 1 to 4. 6. A chemically amplified resist composition according to 5, comprising a base polymer containing a repeating unit represented by the following formula (a1) or (a2): [ka] (In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X 1 is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX 11 -, and the phenylene group or naphthylene group may be substituted with a halogen atom or an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom. 11 is a saturated hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the saturated hydrocarbylene group may contain a hydroxy group, an ether bond, an ester bond or a lactone ring. X 2 is a single bond or *-C(=O)-O-. * indicates a bond to a carbon atom in the main chain. R 11 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. AL 1 and AL 2 are each independently an acid labile group. a is an integer from 0 to 4. 7. The chemically amplified resist composition of 6, wherein the base polymer further contains a repeating unit represented by the following formula (b1) or (b2): [ka] (In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y 1 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. R 21 is a group having 1 to 20 carbon atoms and containing at least one structure selected from a hydrogen atom, a hydroxy group other than a phenolic 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)-). R 22 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. b is an integer from 1 to 4, and c is an integer from 0 to 4, provided that 1≦b+c≦5. 8. The chemically amplified resist composition of 6 or 7, wherein the base polymer further comprises at least one repeating unit selected from the group consisting of repeating units represented by the following formulae (c1) to (c4): [ka] (In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 is a single bond or a phenylene group. Z 2 is *-C(=O)-OZ 21 -, *-C(=O)-NH-Z 21 -or*-OZ 21 -It is. Z 21represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a divalent group obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. Z 3 is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OZ 31 -It is. Z 31 is an aliphatic hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the aliphatic hydrocarbylene group may contain a hydroxy group, an ether bond, an ester bond, or a lactone ring. Z 4 is a single bond or **-Z 41 -C(=O)-O-. Z 41 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Z 5 represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-C(=O)-OZ 51 -, *-C(=O)-N(H)-Z 51 -or*-OZ 51 -It is. Z 51 represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. * represents a bond to a carbon atom in the main chain. ** represents Z 3 Represents a bond with . R 31 and R 32 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 31 and R 32 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached. L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonate ester bond, a carbonate bond or a carbamate bond. Rf1 and Rf 2 are each independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, provided that all Rf 5 and Rf 6 cannot simultaneously become a hydrogen atom. M - is a non-nucleophilic counterion. A + is an onium cation. d is an integer from 0 to 3. 9. The chemically amplified resist composition according to any one of 5 to 8, further comprising an organic solvent. 10. The chemically amplified resist composition of any one of 5 to 9, further comprising a photoacid generator. 11. The chemically amplified resist composition of any one of 5 to 10, further comprising a quencher other than the amine compound represented by formula (1). 12. The resist composition according to any one of 5 to 11, further comprising a surfactant. 13. A pattern forming method comprising the steps of forming a resist film on a substrate using any one of the chemically amplified resist compositions of 5 to 12, exposing the resist film to high-energy rays, and developing the exposed resist film using a developer. 14. The pattern formation method of 13, wherein the high-energy radiation is KrF excimer laser light, ArF excimer laser light, EB, or EUV having a wavelength of 3 to 15 nm. [Effects of the Invention]

[0017] The amine compound of the present invention functions well as a quencher in a resist composition and is characterized by high sensitivity. Furthermore, because the compound contains an acid labile group, the exposed area is decomposed by acid, resulting in a change in polarity and improved dissolution contrast. As a result, LWR and CDU are improved, and a high-resolution pattern profile with excellent rectangularity can be constructed. Furthermore, the novel amine compound of the present invention suppresses swelling of the resist pattern during alkaline development, enabling the formation of a pattern that is resistant to collapse. This makes it possible to provide a resist composition using the novel amine compound of the present invention, which is excellent for forming fine patterns, and a pattern formation method using the resist composition. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a 1H-NMR / DMSO-d6 spectrum of intermediate In-1 of Example 1-1. [Figure 2] 1 is a 19F-NMR / DMSO-d6 spectrum of intermediate In-1 of Example 1-1. [Figure 3] 1 is a 1H-NMR / DMSO-d6 spectrum of intermediate In-2 in Example 1-1. [Figure 4] 1 is a 19F-NMR / DMSO-d6 spectrum of intermediate In-2 in Example 1-1. [Figure 5] 1 is a 1H-NMR / DMSO-d6 spectrum of amine compound AQ-1 of Example 1-1. [Figure 6] 1 is a 19F-NMR / DMSO-d6 spectrum of amine compound AQ-1 of Example 1-1. DETAILED DESCRIPTION OF THE INVENTION

[0019] [Amine compounds] The amine compound of the present invention is represented by the following formula (1): [ka]

[0020] In formula (1), n1 is an integer of 0 or 1. When n1=1, it represents a naphthalene ring, but from the viewpoint of solvent solubility, n1=0, which is a benzene ring, is preferable. n2 is an integer of 1 to 3. From the viewpoint of procurement of starting materials, n2 is preferably 1. n3 is an integer of 1 to 4. When n3≧2, each R F may be the same or different. n4 is an integer of 0 to 4. However, when n1=0, n2+n3+n4≦5, and when n1=1, n2+n3+n4≦7. n5 is an integer of 1 to 3, preferably 1 or 2.

[0021] In formula (1), R AL is an acid labile group formed together with the adjacent oxygen atom. The acid labile group is preferably one represented by the following formula (AL-1) or (AL-2). [ka]

[0022] In formula (AL-1), R 2 , R 3 and R 4 are each independently a hydrocarbyl group having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, in which some of the -CH2- groups in the hydrocarbyl group may be substituted with -O- or -S-, and when the hydrocarbyl group contains an aromatic ring, some or all of the hydrogen atoms in the aromatic ring may be substituted with a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms which may contain a halogen atom, or an alkoxy group having 1 to 4 carbon atoms which may contain a halogen atom.

[0023] R 2 , R 3 and R 4The hydrocarbyl group having 1 to 12 carbon atoms 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 12 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, norbornylmethyl, adamantyl, adamantylmethyl, and tricyclo[5.2.1.0]. 2,6 ]decyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 cyclic saturated hydrocarbyl groups having 3 to 12 carbon atoms, such as a dodecyl group; alkenyl groups having 2 to 12 carbon atoms, such as a vinyl group, allyl group, propenyl group, butenyl group, pentenyl group, and hexenyl group; alkynyl groups having 2 to 12 carbon atoms, such as an ethynyl group, propynyl group, butynyl group, pentynyl group, and hexynyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 12 carbon atoms, such as a cyclopentenyl group and cyclohexenyl group; aryl groups having 6 to 12 carbon atoms, such as a phenyl group, naphthyl group, and indanyl group; aralkyl groups having 7 to 12 carbon atoms, such as a benzyl group, 1-phenylethyl group, and 2-phenylethyl group; and groups obtained by combining these.

[0024] Also, R 2 and R 3 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. The ring formed in this case includes a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a norbornane ring, an adamantane ring, a tricyclo[5.2.1.0 2,6 ] decane ring, tetracyclo[6.2.1.1 3,6 .0 2,7]dodecane ring, etc. In addition, a part of -CH2- in the ring may be substituted with -O- or -S-. However, R 2 and R 3 When they do not bond to each other to form a ring, at least one of them has a ring structure, preferably an alicyclic structure having 3 to 30 carbon atoms or an aromatic ring structure having 6 to 30 carbon atoms.

[0025] In formula (AL-1), m1 is 0 or 1. * represents a bond to the adjacent —O—.

[0026] In formula (AL-2), R 5 and R 6 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms. 5 and R 6 The hydrocarbyl group having 1 to 10 carbon atoms represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 2 , R 3 and R 4 Among the examples of the hydrocarbyl group having 1 to 12 carbon atoms represented by the following formula, those having 1 to 10 carbon atoms can be mentioned.

[0027] In formula (AL-2), R 7is a hydrocarbyl group having 1 to 20 carbon atoms, in which -CH2- may be substituted with -O- or -S-. 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, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl groups; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, norbornylmethyl, adamantyl, adamantylmethyl, and tricyclo[5.2.1.0] groups. 2,6 ]decyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 ]Cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as a dodecyl group; alkenyl groups having 2 to 20 carbon atoms, such as a vinyl group, a propenyl group, a butenyl group, a pentenyl group, or a hexenyl group; alkynyl groups having 2 to 20 carbon atoms, such as an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, or a hexynyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopentenyl group, a cyclohexenyl group, or a norbornenyl group; phenyl group, a methylphenyl group, an ethylphenyl group, an n-propylphenyl group, an isopropyl Examples include aryl groups having 6 to 20 carbon atoms such as a phenyl group, an n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, and a tert-butylnaphthyl group; aralkyl groups having 7 to 20 carbon atoms such as a benzyl group and a phenethyl group; and groups obtained by combining these. 6 and R 7 and are bonded to each other and the carbon atom and L Bmay form a heterocyclic group having 3 to 20 carbon atoms together, and some of the -CH2- in the heterocyclic group may be substituted with -O- or -S-.

[0028] In formula (AL-2), L B is —O— or —S—.

[0029] In formula (AL-2), m2 is 0 or 1. * represents a bond to the adjacent —O—.

[0030] Examples of the acid labile group represented by formula (AL-1) include, but are not limited to, the following: In the following formula, * represents a bond to the adjacent —O—. [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] [ka]

[0040] [ka]

[0041] Examples of the acid labile group represented by formula (AL-2) include, but are not limited to, the following: In the following formula, * represents a bond to the adjacent —O—. [ka]

[0042] [ka]

[0043] In formula (1), R F is a fluorine atom, a fluorine atom-containing saturated hydrocarbyl group having 1 to 6 carbon atoms, a fluorine atom-containing saturated hydrocarbyloxy group having 1 to 6 carbon atoms, or a fluorine atom-containing saturated hydrocarbylthio group having 1 to 6 carbon atoms. Of these, a fluorine atom or a fluorine atom-containing saturated hydrocarbyl group having 1 to 6 carbon atoms is particularly preferred. As the fluorine atom-containing saturated hydrocarbyl group having 1 to 6 carbon atoms, a trifluoromethyl group is preferred. When n3≧2, each R F may be the same as or different from each other.

[0044] In formula (1), R F and -OR ALare bonded to adjacent carbon atoms. Specifically, when n2 and n3 are 1, R F and -OR AL are bonded to adjacent carbon atoms. When at least one of n2 and n3 is 2, at least one R F and -OR AL are bonded to adjacent carbon atoms. AL The acidity of the phenols produced by elimination of the acid labile groups from the compound is improved, and the solubility in an alkaline developer and the swelling suppressing effect are improved.

[0045] In formula (1), R 1is 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, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, and 4-methyl Examples of such groups include saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups. Of these, aryl groups are preferred. Furthermore, 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 -CH- groups of 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 cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, 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.

[0046] When n4≧2, multiple R 1 However, they may be bonded to each other to form a ring together with the carbon atoms on the aromatic ring to which they are bonded. The ring is preferably a 5-membered ring or a 6-membered ring.

[0047] In formula (1), RN1 is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with halogen atoms, and -CH2- of the hydrocarbyl group may be substituted with -O- or -C(=O)-. N1 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 cannot simultaneously become a hydrogen atom.

[0048] R N1 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, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl; saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups.

[0049] Also, two R N1 The ring that can be formed by bonding 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, -CH- in these nitrogen-containing heterocycles may be substituted with -O- or -S-.

[0050] In formula (1), L Ais a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond. Of these, a single bond, an ether bond or an ester bond is preferred, and an ether bond or an ester bond is more preferred.

[0051] In formula (1), X L is a hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom, and is preferably a hydrocarbylene group having 1 to 10 carbon atoms. L Specific examples of the formula include, but are not limited to, the following: In the formula, * represents L A and represents the bond to the nitrogen atom. [ka]

[0052] [ka]

[0053] [ka]

[0054] 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 preferable.

[0055] Examples of the amine compound represented by formula (1) include, but are not limited to, the following: AL and R F This does not apply if and are placed next to each other. [ka]

[0056]

change

[0057]

change

[0058]

change

[0059]

change

[0060]

change

[0061]

change

[0062]

change

[0063]

change

[0064]

change

[0065]

change

[0066]

change

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] The amine compound of the present invention can be produced, for example, according to the following scheme. [ka] (In the formula, n1~n5, R AL , R F , R 1 , L A , X L and R N1 is the same as above. X hal is a chlorine atom, a bromine atom, or an iodine atom.

[0073] 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.

[0074] The synthesis can be carried out by a known organic synthesis method. For example, intermediate In-A is dissolved in a polar aprotic solvent such as acetone, acetonitrile, dimethylformamide, or dimethyl sulfoxide, and a primary or secondary amine is added to the solution 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 or quaternary ammonium iodide. Examples of the alkali metal iodide include sodium iodide and potassium iodide. Examples of the quaternary ammonium iodide include tetraethylammonium iodide and benzyltrimethylammonium iodide. The reaction temperature is preferably in the range from room temperature to the boiling point of the solvent used. From the viewpoint of yield, it is desirable to monitor the reaction by gas chromatography (GC) or silica gel thin-layer chromatography (TLC) to complete the reaction, but the reaction time is usually about 30 minutes to 20 hours. The amine compound represented by formula (1) can be obtained from the reaction mixture by a conventional aqueous work-up. The obtained amine compound can be purified, if necessary, by conventional methods such as chromatography or recrystallization.

[0075] The above-mentioned production method is merely an example, and the method for producing the amine compound of the present invention is not limited to this.

[0076] The structural feature of the amine compound of the present invention is that it has an acid labile group bonded to a hydroxy group on an aromatic ring and a fluorine atom-containing substituent, which are bonded to adjacent carbon atoms. The acid labile group in the exposed region undergoes a deprotection reaction with the generated acid, generating an aromatic hydroxyl group. This improves the contrast between the exposed and unexposed regions. The adjacent fluorine atom-containing substituent not only improves the solubility in resist solvents, but also increases the acidity of the aromatic hydroxyl group generated in the exposed region due to its electron-withdrawing properties. When the resist film is developed with an alkaline developer after exposure, the affinity between the generated aromatic hydroxyl group and the alkaline developer is improved, thereby effectively removing the exposed region with the developer. Furthermore, the aromatic hydroxyl group adjacent to the fluorine atom-containing substituent is thought to attract less alkaline developer to the unexposed region than a carboxyl group due to the water-repellent effect of the fluorine atom, thereby reducing swelling caused by the alkaline developer. This prevents the resist pattern from collapsing in the unexposed region. Due to these synergistic effects, when the amine compound of the present invention is used, it is possible to form a pattern that has high dissolution contrast, excellent LWR of a line pattern, and CDU of a hole pattern, and is resistant to pattern collapse, making it ideal as a positive resist composition.

[0077] [Chemically amplified resist composition] The chemically amplified resist composition of the present invention contains, as an essential component, a quencher (A) consisting of an amine compound represented by formula (1). In the present invention, the quencher is 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.

[0078] In the chemically amplified resist composition of the present invention, the content of the quencher (A) 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 (B) base polymer described below. A content of the (A) quencher within this range is preferable because it provides good sensitivity and resolution and is unlikely to cause problems with foreign matter after development of the resist film or during stripping. The (A) quenchers may be used alone or in combination of two or more.

[0079] [(B) Base polymer] The chemically amplified resist composition of the present invention may contain a base polymer (B). The base polymer (B) contains a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the following formula (a2) (hereinafter also referred to as repeating unit a2). [ka]

[0080] In formulas (a1) and (a2), R A are each independently 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)-OX 11 -, and the phenylene group or naphthylene group may be substituted with a halogen atom or an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom. 11 is a saturated hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the saturated hydrocarbylene group may contain a hydroxy group, an ether bond, an ester bond, or a lactone ring. 2 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. AL 1 and AL 2 are each independently an acid labile group.

[0081] In formula (a2), R 11is 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 1 Examples of the hydrocarbyl group having 1 to 20 carbon atoms represented by the following formula include the same as those exemplified above.

[0082] In formula (a2), a is an integer of 0 to 4, and is preferably 0 or 1.

[0083] X in formula (a1) 1 Examples of structures in which R is changed include, but are not limited to, those shown below. A and AL 1 is the same as above. [ka]

[0084] [ka]

[0085] A polymer containing the repeating unit a1 is decomposed by the action of an acid to produce a carboxyl group, and becomes alkali-soluble.

[0086] AL 1 and AL 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.)

[0087] In formula (L1), R L01 and RL02 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, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-octyl, and 2-ethylhexyl; and cyclic saturated hydrocarbyl groups such as cyclopentyl, cyclohexyl, norbornyl, tricyclodecanyl, tetracyclododecanyl, and adamantyl. As the saturated hydrocarbyl group, one having 1 to 10 carbon atoms is preferred.

[0088] 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- of 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 R 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.)

[0089] R L01 , R L02 and R L03 Any two of the R may be bonded to each other to form a ring together with the carbon atom or carbon atom and oxygen atom to which they are bonded. L01 , R L02 and R L03are each independently an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms.

[0090] 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 having 4 to 20 carbon atoms and containing an ether bond or an ester bond, or a group represented by formula (L1): x is an integer of 0 to 6.

[0091] 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. Examples of the trialkylsilyl group include 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.

[0092] 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, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, and n-hexyl; cyclic saturated hydrocarbyl groups such as cyclopentyl and cyclohexyl; 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.

[0093] In formula (L3), y is 0 or 1, z is an integer of 0 to 3, and 2y+z=2 or 3.

[0094] 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.

[0095] 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, but is preferably a saturated hydrocarbyl group. Examples of the hydrocarbyl group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-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 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 atoms 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 intervening 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.).

[0096] Among the acid labile groups represented by formula (L1), linear or branched groups include, but are not limited to, the groups shown below. [ka] (In the formula, * represents a bond.)

[0097] 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.

[0098] 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.

[0099] 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.

[0100] As the acid labile group represented by formula (L4), groups represented by the following formulae (L4-1) to (L4-4) are particularly preferred. [ka]

[0101] In formulas (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, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, and n-hexyl; and cyclic saturated hydrocarbyl groups such as cyclopentyl and cyclohexyl.

[0102] 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), multiple stereoisomers may be included.

[0103] For example, formula (L4-3) represents a mixture of one or two types 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.)

[0104] Furthermore, formula (L4-4) represents one or a mixture of two or more selected from 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.)

[0105] Formulas (L4-1) to (L4-4), (L4-3-1), (L4-3-2), and formulas (L4-4-1) to (L4-4-4) also represent their enantiomers and mixtures of enantiomers.

[0106] The bonds in formulae (L4-1) to (L4-4), (L4-3-1), (L4-3-2), and (L4-4-1) to (L4-4-4) are exo-oriented relative to the bicyclo[2.2.1]heptane ring, thereby achieving high reactivity in acid-catalyzed elimination reactions (see JP 2000-336121 A). In the production of monomers containing a tertiary exo-saturated hydrocarbyl group as a substituent having a bicyclo[2.2.1]heptane skeleton, monomers substituted with endo-alkyl groups represented by the following formulae (L4-1-endo) to (L4-4-endo) may be included. To achieve good reactivity, the exo-alkyl 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.)

[0107] 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.)

[0108] Also, AL 1 and AL 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), (II), (III), (IV ... L04 Examples of the above-mentioned examples are the same as those given in the explanation of the above.

[0109] Examples of the repeating unit a1 include, but are not limited to, those shown below. A is the same as above. [ka]

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] These specific examples are X 1is a single bond, but X 1 When X 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.

[0115] Polymers containing the repeating unit a2, like the repeating unit a1, are decomposed by the action of an acid to produce a hydroxyl group, and become alkali-soluble. Examples of the repeating unit a2 include, but are not limited to, the following. In the following formula, R A is the same as above. [ka]

[0116] [ka]

[0117] The base polymer preferably further contains a repeating unit represented by the following formula (b1) (hereinafter also referred to as repeating unit b1) or a repeating unit represented by the following formula (b2) (hereinafter also referred to as repeating unit b2). [ka]

[0118] In formulas (b1) and (b2), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. R 21 R is a group having 1 to 20 carbon atoms and containing at least one structure selected from a hydrogen atom, a hydroxy group other than a phenolic 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)-). 22is a hydrocarbyl group having 1 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, provided that 1≦b+c≦5.

[0119] Examples of the repeating unit b1 include, but are not limited to, those shown below. A is the same as above. [ka]

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] [ka]

[0135] [ka]

[0136] [ka]

[0137] Examples of the repeating unit b2 include, but are not limited to, those shown below. A is the same as above. [ka]

[0138] [ka]

[0139] As the repeating unit b1 or b2, those having a lactone ring as a polar group are particularly preferred for ArF lithography, and those having a phenol moiety are preferred for KrF lithography, EB lithography and EUV lithography.

[0140] The base polymer may further contain a repeating unit represented by any one of the following formulas (c1) to (c4) (hereinafter also referred to as repeating units c1 to c4, respectively). These are units that function as a photoacid generator, and when a base polymer containing these is used, the incorporation of the photoacid generator (D), which will be described later, may be omitted. [ka]

[0141] In formulas (c1) to (c4), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 is a single bond or a phenylene group. 2 is *-C(=O)-OZ 21 -, *-C(=O)-NH-Z 21 -or*-OZ 21 -It is. Z 21 Z is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a divalent group obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. 3 is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OZ 31 -It is. Z 31is an aliphatic hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the aliphatic hydrocarbylene group may contain a hydroxy group, an ether bond, an ester bond, or a lactone ring. 4 is a single bond or **-Z 41 -C(=O)-O-. Z 41 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. 5 represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-C(=O)-OZ 51 -, *-C(=O)-N(H)-Z 51 -or*-OZ 51 -It is. Z 51 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. * represents a bond to a carbon atom in the main chain. ** represents a bond to a carbon atom in the main chain. Z 3 Represents a bond with .

[0142] In formula (c1), R 31 and R 32 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 31 and R 32 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached.

[0143] R 31 and R 32The 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, isobutyl, sec-butyl, and tert-butyl; saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Of these, aryl groups are preferred. Furthermore, 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 -CH- groups of 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 lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0144] Examples of the cation of the repeating unit c1 include, but are not limited to, the following: A is the same as above. [ka]

[0145] [ka]

[0146] In formula (c1), M - is a non-nucleophilic counter ion. Examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion; fluoroalkylsulfonate ions such as triflate ion, 1,1,1-trifluoroethanesulfonate ion and nonafluorobutanesulfonate ion; arylsulfonate ions such as tosylate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion and 1,2,3,4,5-pentafluorobenzenesulfonate ion; alkylsulfonate ions such as mesylate ion and butanesulfonate ion; imide ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion and bis(perfluorobutylsulfonyl)imide ion; and methide ions such as tris(trifluoromethylsulfonyl)methide ion and tris(perfluoroethylsulfonyl)methide ion.

[0147] Other examples of the non-nucleophilic counter ion include a sulfonate anion represented by the following formula (c1-1) in which the α-position is substituted with a fluorine atom, and a sulfonate anion represented by the following formula (c1-2) in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group. [ka]

[0148] In formula (c1-1), R 33 is a hydrogen atom or a hydrocarbyl group, and the hydrocarbyl group may contain an ether bond, an ester bond, a carbonyl group, a lactone ring, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A') described below. 111 Examples include those similar to those exemplified in the explanation of .

[0149] In formula (c1-2), R 34is a hydrogen atom, a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbyl carbonyl group having 6 to 20 carbon atoms, and the hydrocarbyl group and the hydrocarbyl carbonyl group may contain an ether bond, an ester bond, a carbonyl group, or a lactone ring. The hydrocarbyl moiety of the hydrocarbyl group and the hydrocarbyl carbonyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A') described below. 111 Examples include those similar to those exemplified in the explanation of .

[0150] Specific examples of the sulfonate anion represented by the non-nucleophilic counter ion include, but are not limited to, those shown below. 35 represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms, and Ac represents an acetyl group. [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] [ka]

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] In formula (c2), Z 41 Examples of the hydrocarbylene group having 1 to 20 carbon atoms and optionally containing a hetero atom, represented by the following, include, but are not limited to, the following: [ka] (In the formula, the dashed lines represent bonds.)

[0159] In formulas (c2) and (c3), L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonate ester bond, a carbonate bond or a carbamate bond.

[0160] In formulas (c2) and (c3), Rf 1 and Rf 2 are each independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, but are preferably all fluorine atoms in order to increase the acid strength of the generated acid. 3 and Rf 4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, but in order to improve solvent solubility, it is preferable that at least one of them is a trifluoromethyl group. 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, provided that all Rf 5 and Rf 6 and are not simultaneously hydrogen atoms. d is an integer of 0 to 3, and is particularly preferably 1.

[0161] Examples of the anion of the repeating unit represented by formula (c2) include, but are not limited to, those shown below. A is the same as above. [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] Specific examples of the anion of the repeating unit represented by formula (c3) include, but are not limited to, those shown below. A is the same as above. [ka]

[0166] [ka]

[0167] Specific examples of the anion of the repeating unit represented by formula (c4) include, but are not limited to, those shown below. A is the same as above. [ka]

[0168] In formulas (c2), (c3) and (c4), A +is an onium cation. Examples of the onium cation include a sulfonium cation, an iodonium cation, and an ammonium cation. The onium cation is preferably a sulfonium cation or an iodonium cation, and more preferably a sulfonium cation represented by the following formula (c5) or an iodonium cation represented by the following formula (c6). [ka]

[0169] In formulas (c5) and (c6), R 36 ~R 40are each independently 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, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Of these, aryl groups are preferred. Furthermore, 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 -CH- groups of 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 lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0170] R 36 and R 37 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, examples of the sulfonium cation represented by formula (c5) include those represented by the following formulas: [ka] (In the formula, the dashed line indicates R 38 )

[0171] Examples of the sulfonium cation represented by formula (c5) include, but are not limited to, those shown below. [ka]

[0172] [ka]

[0173] [ka]

[0174] [ka]

[0175] [ka]

[0176] [ka]

[0177] [ka]

[0178] [ka]

[0179] [ka]

[0180] [ka]

[0181]

change

[0182]

change

[0183]

change

[0184]

change

[0185]

change

[0186]

change

[0187]

change

[0188]

change

[0189]

change

[0190]

change

[0191]

change

[0192] [ka]

[0193] Examples of the iodonium cation represented by formula (c6) include, but are not limited to, those shown below. [ka]

[0194] The repeating units c1 to c4 include any combination of the above-mentioned anions and cations.

[0195] The base polymer may further contain a repeating unit having a structure in which a hydroxy group is protected by an acid labile group (hereinafter also referred to as repeating unit d). The repeating unit d is not particularly limited as long as it has one or more structures in which a hydroxy group is protected and the protecting group is decomposed by the action of an acid to generate a hydroxy group, but is preferably one represented by the following formula (d1): [ka]

[0196] In formula (d1), R A is the same as above. e is an integer of 1 to 4. R 41 R is a hydrocarbon group having 1 to 30 carbon atoms and a valence of (e+1), which may contain a heteroatom. 42 is an acid labile group.

[0197] In formula (d1), R 42 The acid labile group represented by R may be any group that can be deprotected by the action of an acid to generate a hydroxy group. 42Although the structure is not particularly limited, an acetal structure, a ketal structure, an alkoxycarbonyl group, an alkoxymethyl group represented by the following formula (d2), and the like are preferred, and an alkoxymethyl group represented by the following formula (d2) is particularly preferred. [ka] (In the formula, * represents a bond. R 43 is a hydrocarbyl group having 1 to 15 carbon atoms.

[0198] R 42 Specific examples of the acid labile group represented by the formula (d2), the alkoxymethyl group represented by the formula (d3), and the repeating unit d are the same as those exemplified in the description of the repeating unit d described in JP-A-2020-111564.

[0199] The base polymer may further contain other repeating units than those described above, such as 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 ] It may contain repeating units derived from cyclic olefins such as dodecene derivatives; unsaturated acid anhydrides such as itaconic anhydride; or other monomers.

[0200] The weight-average molecular weight (Mw) of the base polymer is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. When Mw is within this range, sufficient etching resistance is obtained, and there is no risk of a decrease in resolution due to an 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.

[0201] If the base polymer has a broad molecular weight distribution (Mw / Mn), low-molecular-weight and high-molecular-weight polymers will be present, which may result in the appearance of foreign matter on the pattern or deterioration of the pattern shape after exposure. Therefore, as the pattern rule becomes finer, the influence of Mw / Mn tends to become greater. Therefore, 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.

[0202] To synthesize the base polymer, for example, a monomer that provides the repeating unit described above may be polymerized by heating in an organic solvent with the addition of a radical polymerization initiator.

[0203] One example of a method for synthesizing the base polymer is to heat one or more monomers having unsaturated bonds in an organic solvent with the addition of a radical initiator to polymerize them. Examples of organic solvents used in the polymerization reaction include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (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% of 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.

[0204] The polymerization initiator may be added to the monomer solution and then fed to the reaction vessel. Alternatively, an initiator solution may be prepared separately from the monomer solution and then fed to the reaction vessel independently. From the perspective of quality control, it is preferable to prepare the monomer solution and the initiator solution independently and then add them dropwise, since radicals generated from the initiator during the waiting time may cause the polymerization reaction to proceed, resulting in the formation of ultra-high molecular weight polymers. The acid labile group may be used as is after being introduced into the monomer, or may be protected or partially protected after polymerization. Furthermore, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol may be used in combination to adjust the molecular weight. In this case, the amount of the chain transfer agent added is preferably 0.01 to 20 mol % of the total amount of monomers to be polymerized.

[0205] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene and other monomers may be polymerized by heating in an organic solvent with the addition of a radical polymerization initiator. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene may be used, and after polymerization, the acetoxy group may be deprotected by alkaline hydrolysis to form polyhydroxystyrene or hydroxypolyvinylnaphthalene.

[0206] The base that can be used in alkaline hydrolysis includes aqueous ammonia, triethylamine, etc. 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.

[0207] The amount of each monomer in the monomer solution may be appropriately set so as to achieve the preferred content ratio of the repeating units described above.

[0208] 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 process in which the polymerization solution is added to a poor solvent to obtain a powder, and the final product may be handled as the final product. However, from the viewpoint of work efficiency and quality stability, it is preferable to handle the polymer solution obtained by dissolving the powder obtained by the purification process in a solvent as the final product. Specific examples of solvents 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 suitable solvents 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.

[0209] The concentration of the polymer in the polymer solution is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass.

[0210] The reaction solution and polymer solution are preferably filtered through a filter, which is effective in stabilizing quality by removing foreign matter and gels that may cause defects.

[0211] Examples of filter materials used in the filter filtration include fluorocarbon, cellulose, nylon, polyester, and hydrocarbon-based materials. However, in the filtration process for chemically amplified resist compositions, filters made of fluorocarbons, such as Teflon (registered trademark), hydrocarbons such as polyethylene and polypropylene, or nylon are preferred. The pore size of the filter can be selected appropriately depending on the desired cleanliness, but is preferably 100 nm or less, more preferably 20 nm or less. These filters may be used alone or in combination. The filtration method may involve passing the solution through the filter only once, but it is more preferable to circulate the solution and filter it multiple times. The filtration process can be performed in any order and any number of times during the polymer production process. However, it is preferable to filter the reaction solution after the polymerization reaction, the polymer solution, or both.

[0212] In the base polymer, the preferred content ratio of each repeating unit can be, for example, within the ranges (mol %) shown below, but is not limited thereto. (I) one or more of the repeating units a1 or a2 preferably accounts for 1 to 60 mol %, more preferably 5 to 50 mol %, and even more preferably 10 to 50 mol %, (II) one or more of the repeating units b1 or b2 is preferably 40 to 99 mol %, more preferably 50 to 95 mol %, and even more preferably 50 to 90 mol %, (III) one or more repeating units selected from repeating units c1 to c4, preferably 0 to 30 mol %, more preferably 0 to 20 mol %, and even more preferably 0 to 15 mol %, and (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 %.

[0213] The base polymer may be used alone or in combination of two or more types differing in composition, Mw, and / or Mw / Mn. In addition to the above-mentioned polymer, the (B) base polymer may also contain a hydrogenated ring-opening metathesis polymer, and the polymers described in JP-A-2003-66612 can be used.

[0214] [(C) Organic solvent] The chemically amplified resist composition of the present invention may further comprise (C) an organic solvent. There are no particular restrictions on the organic solvent (C) as long as it is capable of dissolving the components described above and the components described below. 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; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene 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.

[0215] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA, and mixed solvents thereof are preferred, as they have particularly excellent solubility for the base polymer of component (B).

[0216] In the chemically amplified resist composition of the present invention, the content of (C) organic solvent is preferably 200 to 5000 parts by mass, more preferably 400 to 3500 parts by mass, relative to 80 parts by mass of (B) base polymer. (C) The organic solvent may be used alone or in combination of two or more types.

[0217] [(D) Photoacid generator] The chemically amplified resist composition of the present invention may contain (D) a photoacid generator. The photoacid generator (D) is not particularly limited as long as it is a compound that generates an acid upon irradiation with KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light (hereinafter, these are also collectively referred to as high-energy rays). Suitable photoacid generators include those represented by the following formula (2-1) or (2-2): [ka]

[0218] In formulas (2-1) and (2-2), R 101 ~R 105 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 101 and R 102 However, they may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. The hydrocarbyl group includes R 36 ~R 40 Examples of the above-mentioned examples are the same as those given in the explanation of the above.

[0219] Examples of the cation of the sulfonium salt represented by formula (2-1) include the same as those exemplified as the sulfonium cation represented by formula (c5). Examples of the cation of the iodonium salt represented by formula (2-2) include the same as those exemplified as the iodonium cation represented by formula (c6).

[0220] In formulas (2-1) and (2-2), Xa - is an anion selected from the following formulae (2A) to (2D). [ka]

[0221] In formula (2A), R fa is 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 in formula (2A') described below. 111 Examples include those similar to those exemplified in the explanation of .

[0222] The anion represented by formula (2A) is preferably one represented by the following formula (2A'). [ka]

[0223] In formula (2A'), R HF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group.

[0224] In formula (2A'), R 111 is a hydrocarbyl group having 1 to 38 carbon atoms which may contain a heteroatom. As the hydrocarbyl group, those having 6 to 30 carbon atoms are particularly preferred in terms of obtaining high resolution in fine pattern formation.

[0225] R 111The hydrocarbyl group having 1 to 38 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 38 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-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, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl 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, and a 1-adamantylmethyl group. Examples of such groups include saturated cyclic hydrocarbyl groups having 3 to 38 carbon atoms, such as an allyl group, a norbornyl group, a norbornylmethyl group, a tricyclodecyl group, a tetracyclododecyl group, a tetracyclododecylmethyl group, and a dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups having 2 to 38 carbon atoms, such as an allyl group and a 3-cyclohexenyl group; aryl groups having 6 to 38 carbon atoms, such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group; aralkyl groups having 7 to 38 carbon atoms, such as a benzyl group and a diphenylmethyl group; and groups obtained by combining these groups.

[0226] Furthermore, 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 -CH- groups of 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 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]. 3,7 ]nonan-5-on-2-yl group, 3-oxocyclohexyl group, and the like.

[0227] Synthesis of sulfonium salts having an anion represented by formula (2A') is described in detail in JP-A Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. In addition, sulfonium salts described in JP-A Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also suitable.

[0228] Examples of the anion represented by formula (2A) include the same anions as those exemplified as the anions represented by formulae (c1-1) and (c1-2).

[0229] In formula (2B), R fb1 and R fb2are 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 in formula (2A'). 111 Examples of the hydrocarbyl group represented by 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 form the bonded group (-CF2-SO2-N - -SO2-CF2-) together 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.

[0230] 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 in formula (2A'). 111 Examples of the hydrocarbyl group represented by 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 fc2 are bonded to each other and form the bonded group (-CF2-SO2-C - -SO2-CF2-) together may form a ring, in which case R fc1 and R fc2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0231] In formula (2D), R fdis 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. Specific examples thereof include R in formula (2A'). 111 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0232] The synthesis of sulfonium salts having an anion represented by formula (2D) is described in detail in JP-A-2010-215608 and JP-A-2014-133723.

[0233] Examples of the anion represented by formula (2D) include the same anions as those exemplified as the anion represented by formula (1D) in JP 2018-197853 A.

[0234] 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 groups in the base polymer, making it suitable for use as a photoacid generator.

[0235] Furthermore, the photoacid generator of the component (D) is preferably one represented by the following formula (3). [ka]

[0236] In formula (3), R 201 and R 202 R are each independently a hydrocarbyl group having 1 to 30 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 may be bonded to each other to form a ring together with the sulfur atom to which they are attached.

[0237] R201 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 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; 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 30 carbon atoms such as a phenyl group, a methylphenyl group, an ethylphenyl group, an n-propylphenyl group, an isopropylphenyl group, an n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group, an anthracenyl group, and the like; and groups obtained by combining these. Furthermore, 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 -CH- groups of 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 lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0238] 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 30 carbon atoms, such as methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group; cyclopentanediyl group, cyclohexene-1,18-diyl group, and the like. Examples of the alkylene groups include cyclic saturated hydrocarbylene groups having 3 to 30 carbon atoms, such as xanediyl, norbornanediyl, and adamantanediyl; arylene groups having 6 to 30 carbon atoms, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene; and groups obtained by combining these groups. 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- groups of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in the hydrocarbylene group containing 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. As the heteroatom, an oxygen atom is preferred.

[0239] In formula (3), L Ais a single bond, an ether bond, or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbylene group 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.

[0240] In formula (3), X a , X b , X c and X d are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that X a , X b , X c and X d At least one of the groups is a fluorine atom or a trifluoromethyl group.

[0241] The photoacid generator represented by formula (3) is preferably one represented by the following formula (3'). [ka]

[0242] In formula (3'), L A is the same as above. X e is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 301 , R 302 and R 303 are each independently a hydrogen atom or 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 in formula (2A'). 111 Examples of the hydrocarbyl group represented by m include the same as those exemplified above. 1 and m 2 are each independently an integer of 0 to 5, and m 3 is an integer from 0 to 4.

[0243] Examples of the photoacid generator represented by formula (3) include the same compounds as those exemplified as the photoacid generator represented by formula (2) in JP-A-2017-026980.

[0244] Among the other photoacid generators, those containing anions represented by formula (2A') or (2D) are particularly preferred because of their small acid diffusion and excellent solubility in solvents. Also, those represented by formula (3') are particularly preferred because of their extremely small acid diffusion.

[0245] When the chemically amplified resist composition of the present invention contains a (D) photoacid generator, the content thereof is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 20 parts by mass, per 80 parts by mass of the (B) base polymer. When the amount of (D) photoacid generator added is within the above range, the resolution is 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 (D) photoacid generators may be used alone or in combination of two or more.

[0246] [(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 other quenchers for component (E) include onium salts represented by the following formula (4-1) or (4-2). [ka]

[0247] In formula (4-1), R 401 represents a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom, but excludes 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.

[0248] R 401The 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 a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, and 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, an oxanorbornyl group, and a tricyclo[5.2.1.0] 2,6 cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms, such as a ]decanyl group or an adamantyl group; aryl groups having 6 to 40 carbon atoms, such as a phenyl group, a naphthyl group or an anthracenyl group; and groups obtained by combining these. Some or all of the hydrogen atoms in the hydrocarbyl groups may be substituted with groups containing heteroatoms, such as oxygen atoms, sulfur atoms, nitrogen atoms or halogen atoms, and some of the -CH2- groups in the hydrocarbyl groups may be substituted with groups containing heteroatoms, such as oxygen atoms, sulfur atoms or nitrogen atoms, so that the hydrocarbyl groups may contain hydroxy groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0249] In formula (4-2), R 402 is a hydrogen atom or a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. 401 In addition to the specific examples of the substituents, examples 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.

[0250] Examples of the anion of the onium salt represented by formula (4-1) include, but are not limited to, those shown below. [ka]

[0251] [ka]

[0252] Examples of the anion of the onium salt represented by formula (4-2) include, but are not limited to, those shown below. [ka]

[0253] [ka]

[0254] 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]

[0255] In formulas (4A) to (4C), R 411 ~R 419 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. 411 and R 412 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and R 416 and R 417 and may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. 401 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0256] MQ + Specific examples of the onium cation represented by the formula (I) include, but are not limited to, those shown below. [ka]

[0257] [ka]

[0258] [ka]

[0259] Specific examples of the onium salts represented by formula (4-1) or (4-2) include any combination of the anions and cations described above. These onium salts can be easily prepared by ion exchange reactions using known organic chemistry methods. For details on ion exchange reactions, see, for example, JP 2007-145797 A.

[0260] 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 the counter anion of each onium salt is the conjugate base of a weak acid. The term "weak acid" as used herein refers to an acidity that is insufficient to deprotect the acid labile group in 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 counter anion that is the conjugate base of a strong acid, such as a sulfonic acid fluorinated at the α-position. Specifically, when an onium salt that generates a strong acid, such as a sulfonic acid fluorinated at the α-position, is mixed with an onium salt that generates a weak acid, such as a sulfonic acid or carboxylic acid that is not fluorinated, the strong acid generated from the photoacid generator upon irradiation with high-energy radiation collides with an onium salt having an unreacted weak acid anion, releasing the weak acid through salt exchange and generating an onium salt having a strong acid anion. In this process, the strong acid is exchanged for a weak acid with a lower catalytic activity, and the acid appears to be deactivated, allowing for control of acid diffusion.

[0261] 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 thought that the weak acid generated by irradiation with high-energy rays collides with the unreacted onium salt that generates the strong acid, making it difficult to carry out 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.

[0262] When the onium salt represented by formula (4-1) or (4-2) is contained as the (E) other quencher, the content thereof 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 (B) base polymer. The content of the onium salt within the above range is preferable because the resolution is good and there is no significant decrease in sensitivity. The onium salt represented by formula (4-1) or (4-2) may be used alone or in combination of two or more.

[0263] Nitrogen-containing compounds other than component (A) can also be used as other quenchers in component (E). Examples of such nitrogen-containing compounds include primary, secondary, or tertiary amine compounds described in paragraphs

[0146] to

[0164] of JP 2008-111103 A, particularly amine compounds having a hydroxy group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate ester bond. Other examples include compounds in which a primary or secondary amine is protected with a carbamate group, such as the compounds described in JP 3790649 A.

[0264] Alternatively, a sulfonate sulfonium salt having a nitrogen-containing substituent may be used as the nitrogen-containing compound. Such a compound functions as a quencher in the unexposed area and loses its quenching ability in the exposed area by neutralizing with the acid generated by the compound itself, functioning as a so-called photodegradable base. The use of a photodegradable base can further enhance the contrast between the exposed and unexposed areas. For example, JP-A Nos. 2009-109595 and 2012-46501 can be used as references for the photodegradable base.

[0265] When a nitrogen-containing compound is contained as another quencher of the component (E), the content thereof is preferably 0.001 to 12 parts by mass, more preferably 0.01 to 8 parts by mass, relative to 80 parts by mass of the base polymer (B).The nitrogen-containing compound may be used alone or in combination of two or more types.

[0266] [(F) Surfactant] The chemically amplified resist composition of the present invention may further comprise a surfactant (F). The surfactant (F) is preferably a surfactant that is insoluble or slightly soluble in water but soluble in an alkaline developer, or a surfactant that is insoluble or slightly soluble in both water and an alkaline developer. Examples of such surfactants include those described in JP-A-2010-215608 and JP-A-2011-16746.

[0267] Among the surfactants described in the above publications, preferred surfactants that are insoluble or slightly 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 oxetane ring-opening polymers represented by the following formula (surf-1): [ka]

[0268] Here, R, Rf, A, B, C, m, and n apply only to formula (surf-1), regardless of the above descriptions. R is a divalent to tetravalent aliphatic group having 2 to 5 carbon atoms. Examples of the divalent aliphatic group include an ethylene group, a 1,4-butylene group, a 1,2-propylene group, a 2,2-dimethyl-1,3-propylene group, and a 1,5-pentylene group, and examples of the trivalent or tetravalent aliphatic group include the following: [ka] (In the formula, the dashed lines represent bonds and are partial structures derived from glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol, respectively.)

[0269] Among these, a 1,4-butylene group, a 2,2-dimethyl-1,3-propylene group, and the like are preferred.

[0270] 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 the structural units in formula (surf-1) is not specified, and they may be bonded in blocks or randomly. The production of partially fluorinated oxetane ring-opening polymer surfactants is described in detail in the specification of U.S. Pat. No. 5,650,483, etc.

[0271] Surfactants that are insoluble or slightly soluble in water but soluble in alkaline developers have the function of reducing water penetration and leaching by orienting themselves on the surface of the resist film when a resist protective film is not used in ArF immersion lithography. Therefore, they are useful for suppressing the elution of water-soluble components from the resist film and reducing damage to the exposure equipment. They are also useful because they become soluble during alkaline aqueous development after exposure or PEB, making them less likely to become contaminants that could cause defects. Such surfactants are insoluble or slightly soluble in water but soluble in alkaline developers. They are polymeric surfactants, also known as hydrophobic resins, and are particularly preferred because they have high water repellency and improve water slippage.

[0272] Such polymer surfactants include those containing at least one repeating unit selected from those represented by any of the following formulae (5A) to (5E). [ka]

[0273] In formulas (5A) to (5E), R B is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 is -CH2-, -CH2CH2-, -O- or two -H groups 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 hydrocarbon group or a fluorinated hydrocarbon group having 1 to 20 carbon atoms and a valence of (u+1). u is an integer of 1 to 3. R s5 are each independently a hydrogen atom or -C(=O)-OR sa R sa 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.

[0274] 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.

[0275] R s2 The hydrocarbylene group represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group.

[0276] R s3 or R s6The hydrocarbyl group represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkyl groups, alkenyl groups, and alkynyl groups, with alkyl groups being preferred. s1 In addition to the examples of the hydrocarbyl group represented by the formula (R), examples 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 (I) include groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbyl group have been substituted with fluorine atoms. As mentioned above, an ether bond or a carbonyl group may be present between these carbon-carbon bonds.

[0277] 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.

[0278] R s4 The (u+1)-valent hydrocarbon group or fluorinated hydrocarbon group represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include groups obtained by further eliminating u hydrogen atoms from the aforementioned hydrocarbyl group or fluorinated hydrocarbyl group.

[0279] R saThe 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, 2-(perfluorodecyl)ethyl group, and the like.

[0280] Examples of the repeating unit represented by any one of formulas (5A) to (5E) include, but are not limited to, the following: B is the same as above. [ka]

[0281] [ka]

[0282] [ka]

[0283] [ka]

[0284] [ka]

[0285] The polymer surfactant may further contain other repeating units in addition to the repeating units represented by formulae (5A) to (5E). Examples of such 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) is preferably 20 mol % or more, more preferably 60 mol % or more, and even more preferably 100 mol %, of all repeating units.

[0286] 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.

[0287] The polymer surfactant can be synthesized by heating a monomer containing an unsaturated bond that provides the repeating units represented by formulas (5A) to (5E) and, if necessary, other repeating units, in an organic solvent with the addition of a radical initiator to polymerize the monomer. Examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dioxane. Examples of polymerization initiators 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 is, or may be protected or partially protected after polymerization.

[0288] When synthesizing the polymer 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 number of moles of the monomers to be polymerized.

[0289] When the chemically amplified resist composition of the present invention contains a surfactant (F), the content thereof is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass, per 80 parts by mass of the base polymer (B). When 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, while when the surfactant content 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 types.

[0290] [Other ingredients] The chemically amplified resist composition of the present invention may further include a compound that decomposes in the presence of acid to generate acid (acid amplifier compound), an organic acid derivative, a fluorine-substituted alcohol, or a compound with a Mw of 3000 or less whose solubility in a developer changes upon the action of acid (dissolution inhibitor). Examples of the acid amplifier compound include the compounds described in JP-A-2009-269953 and JP-A-2010-215608. When the acid amplifier compound is included, its content is preferably 0 to 5 parts by weight, more preferably 0 to 3 parts by weight, relative to 80 parts by weight of the (B) base polymer. If the content is too high, it may be difficult to control acid diffusion, resulting in degradation of resolution and pattern shape. Examples of the organic acid derivative, fluorine-substituted alcohol, and dissolution inhibitor include the compounds described in JP-A-2009-269953 and JP-A-2010-215608.

[0291] [Pattern formation method] The pattern forming method of the present invention includes the steps of forming a resist film on a substrate using the aforementioned chemically amplified resist composition, exposing the resist film to high-energy rays, and developing the exposed resist film using a developer.

[0292] The substrate may be, for example, a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coating, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0293] The resist film can be formed, for example, by applying the chemically amplified resist composition onto a substrate by a method such as spin coating so that the film thickness is preferably 0.05 to 2 μm, and then pre-baking the composition 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.

[0294] Examples of high-energy rays used to expose the resist film include KrF excimer laser light, ArF excimer laser light, EB, EUV, etc. When KrF excimer laser light, ArF excimer laser light, or EUV is used for exposure, a mask for forming a desired pattern is used, and the exposure dose is preferably 1 to 200 mJ / cm. 2 , more preferably 10 to 100 mJ / cm 2 When 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

[0295] In addition to the usual exposure method, the immersion method can also be used, in which a liquid with a refractive index of 1.0 or higher is placed between the resist film and the projection lens. In this case, a water-insoluble protective film can also be used.

[0296] The water-insoluble protective film is used to prevent elution from the resist film and increase the water sliding property of the film surface. It can be broadly divided into two types. One is an organic solvent-removable type that requires stripping before alkaline aqueous development using an organic solvent that does not dissolve the resist film. The other is an alkaline aqueous solution-soluble type that is soluble in alkaline developer and removes the protective film along with removing the soluble portion of the resist film. The latter is particularly based on a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues that is insoluble in water but soluble in alkaline developer, and is preferably dissolved in an alcohol solvent with 4 or more carbon atoms, an ether solvent with 8 to 12 carbon atoms, or a mixed solvent thereof. Materials can also be prepared by dissolving the water-insoluble, alkaline developer-soluble surfactant described above in an alcohol solvent with 4 or more carbon atoms, an ether solvent with 8 to 12 carbon atoms, or a mixed solvent thereof.

[0297] After the exposure, PEB may be performed by heating on a hot plate, for example, preferably at 60 to 150° C. for 1 to 5 minutes, more preferably at 80 to 140° C. for 1 to 3 minutes.

[0298] The development is carried out using a developer, for example, an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH) or the like, preferably at 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 dipping, puddling, or spraying, whereby the exposed areas are dissolved and the desired pattern is formed on the substrate.

[0299] After forming the resist film, the resist film may be rinsed with pure water to extract the acid generator and the like from the film surface or to wash away particles, or the resist film may be rinsed after exposure to remove water remaining on the film.

[0300] Furthermore, the pattern may be formed by a double patterning method, such as a trench method in which a first exposure and etching process is performed to process an underlayer with a 1:3 trench pattern, and then a second exposure process is performed with a shifted position to form a 1:3 trench pattern, thereby forming a 1:1 pattern, or a line method in which a first underlayer with a 1:3 isolated leave pattern is processed by a first exposure and etching process, and then a second exposure process is performed with a shifted position to process a second underlayer with a 1:3 isolated leave pattern formed below the first underlayer, thereby forming a 1:1 pattern with half the pitch.

[0301] In the pattern forming method of the present invention, a negative tone development method may be used in which an organic solvent is used as the developer instead of the alkaline aqueous solution to dissolve the unexposed areas.

[0302] The organic solvent development may be performed using the following developers: 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 methyl methyl valerate, methyl pentenoate, methyl crotonate, ethyl methyl crotonate, propyl methyl methyl valerate, propyl methyl methyl pentenoate, propyl methyl methyl crotonate, propyl methyl methyl methyl crotonate, propyl methyl methyl methyl valerate, propyl methyl methyl pentenoate, propyl methyl methyl methyl crotonate, propyl methyl methyl methyl hexano ... Examples of organic solvents 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, ethyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, and 2-phenylethyl acetate. These organic solvents may be used alone or in combination of two or more. [Example]

[0303] The present invention will be specifically explained below by showing 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.

[0304] [1] Synthesis of amine compounds [Example 1-1] Synthesis of amine compound AQ-1 (1) Synthesis of intermediate In-1 [ka]

[0305] Under a nitrogen atmosphere, sodium hydride (10.9 g, 55% by mass purity) was suspended in THF (60 g), and a solution consisting of 1-isopropylcyclopentanol (35.3 g) and THF (30 g) was added dropwise. After the dropwise addition, the mixture was heated under reflux for 4 hours to prepare a metal alkoxide. Then, the starting material SM-1 (48.3 g) was added dropwise, and the mixture was heated under reflux and aged for 18 hours. The reaction solution was cooled in an ice bath, and the reaction was quenched with water (100 g). The target product was extracted twice with a solvent consisting of toluene (100 g) and hexane (100 g), followed by standard aqueous work-up. The solvent was distilled off, and the resulting mixture was purified by distillation to obtain 51.2 g of intermediate In-1 as a colorless oil (yield 68%, impurities remaining).

[0306] (2) Synthesis of intermediate In-2 [ka]

[0307] A Grignard reagent was prepared from magnesium metal (4.1 g), intermediate In-1 (51.2 g), and THF (200 g) under a nitrogen atmosphere. This Grignard reagent was added dropwise to a suspension of dry ice (200 g) in THF (500 g). After the addition, the mixture was aged until the dry ice sublimated. After aging, the reaction mixture was maintained at 10°C or below, and 5% by mass hydrochloric acid (150 g) was added dropwise to quench the reaction. The mixture was then extracted with ethyl acetate (600 g), subjected to standard aqueous work-up, and the solvent was evaporated. The mixture was then recrystallized from hexane to obtain intermediate In-2 as white crystals (yield: 26.8 g, 58%).

[0308] (3) Synthesis of amine compound AQ-1 [ka]

[0309] Under a nitrogen atmosphere, 15.1 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (WSC·HCl) was added to a solution of intermediate In-2 (15.0 g), morpholine ethanol (8.9 g), dimethylaminopyridine (0.7 g), and methylene chloride (50 g) and stirred for 12 hours. The reaction mixture was cooled in an ice bath and quenched with 100 g of 1% by weight aqueous hydrochloric acid. After standard aqueous work-up, the solvent was evaporated, yielding 17.9 g of amine compound AQ-1 as a colorless oil (84% yield).

[0310] [Example 1-2] Synthesis of amine compound AQ-2 (1) Synthesis of intermediate In-3 [ka]

[0311] Under a nitrogen atmosphere, a solution of intermediate In-2 (15.0 g), bromoethanol (8.5 g), dimethylaminopyridine (0.7 g), and methylene chloride (50 g) was added with WSC·HCl (15.1 g) and stirred for 12 hours. The reaction mixture was cooled in an ice bath and quenched with 1% by weight aqueous hydrochloric acid (100 g). After standard aqueous work-up, the solvent was evaporated, yielding intermediate In-3 (18.2 g, 87% yield) as a colorless oil.

[0312] (2) Synthesis of amine compound AQ-2 [ka]

[0313] Under a nitrogen atmosphere, intermediate In-3 (18.2 g), sodium iodide (0.7 g), and acetone (70 g) were charged into a reaction vessel, and piperidine (4.7 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-3 by TLC, the reaction solution was cooled to room temperature and the reaction was quenched with saturated aqueous sodium bicarbonate (35 g). The acetone was then removed using an evaporator. After removal, methylene chloride (105 g) was added to extract the target product, and the layers were separated. The resulting organic layer was washed four times with water (35 g) and once with saturated brine (35 g). The organic layer was separated and concentrated to obtain amine compound AQ-2 as an oil (yield: 16.2 g, 89%).

[0314] [Examples 1-3 to 1-7] Synthesis of amine compounds AQ-3 to AQ-7 Amine compounds AQ-3 to AQ-7 were synthesized by various organic synthesis methods. The structures of amine compounds AQ-3 to AQ-7 are shown below. [ka]

[0315] [2] Synthesis of base polymer The base polymer used in the chemically amplified resist composition was synthesized by the following method: The Mw of the resulting polymer was measured in terms of polystyrene by GPC using THF as the solvent.

[0316] [Synthesis Example 1] Synthesis of Polymer P-1 Under a nitrogen atmosphere, a flask was charged with 5.0 g of 3-hydroxy-1-adamantyl methacrylate, 14.4 g of α-methacryloxy-γ-butyrolactone, 20.8 g of 1-isopropylcyclopentyl methacrylate, 0.49 g of V-601 (Fujifilm Wako Pure Chemical Industries, Ltd.), 0.41 g of 2-mercaptoethanol, and 56 g of PGMEA to prepare a monomer-polymerization initiator solution. In a separate flask under a nitrogen atmosphere, 19 g of PGMEA was charged and heated to 80°C with stirring, after which the monomer-polymerization initiator solution was added dropwise over 4 hours. After completion of the dropwise addition, stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80°C, and then the mixture was cooled to room temperature. The resulting polymerization solution was added dropwise to 640 g of vigorously stirred methanol, and the precipitated polymer was separated by filtration. The resulting polymer was washed twice with 240 g of methanol and then vacuum dried at 50°C for 20 hours to obtain polymer P-1 as a white powder (yield: 35.3 g, 88%). GPC analysis revealed that polymer P-1 had an Mw of 8500 and an Mw / Mn ratio of 1.56. [ka]

[0317] [Synthesis Examples 2 to 7] Synthesis of polymers P-2 to P-7 Except for changing the types and blending ratios of monomers, polymers P-2 to P-7 were synthesized in the same manner as in Synthesis Example 1. The types and introduction ratios of repeating units of polymers P-1 to P-7 are shown in Table 1 below.

[0318] [Table 1]

[0319] In Table 1, the repeating units are as follows: [ka]

[0320] [ka]

[0321] [ka]

[0322] [3] Preparation of chemically amplified resist composition [Examples 2-1 to 2-22, Comparative Examples 1-1 to 1-14] The amine compounds of the present invention (AQ-1 to AQ-7), comparative amine quenchers (AQ-A to AQ-F), base polymers (P-1 to P-7), photoacid generators (PAG-1 to PAG-3), quenchers (Q-1, Q-2), and alkali-soluble surfactant (SF-1) were dissolved in a solvent containing 0.01 mass% of surfactant A (Omnova) in the compositions shown in Tables 2 and 3 below. The solutions were then filtered through a 0.2 μm Teflon (registered trademark) filter to prepare chemically amplified resist compositions (R-1 to R-22, CR-1 to CR-14).

[0323] [Table 2]

[0324] [Table 3]

[0325] In Tables 2 and 3, the solvent, alkali-soluble surfactant SF-1, photoacid generators PAG-1 to PAG-3, quenchers Q-1 and Q-2, and comparative amine quenchers AQ-A to AQ-F are as follows. Solvent: PGMEA (propylene glycol monomethyl ether acetate) GBL (γ-butyrolactone) DAA (diacetone alcohol)

[0326] Alkali-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] methacrylate 3,7 ]nonan-5-on-2-yl) [ka] Mw=7700, Mw / Mn=1.82

[0327] Photoacid generators: PAG-1 to PAG-3 [ka]

[0328] Quencher: Q-1, Q-2 [ka]

[0329] Amine quenchers for comparison: AQ-A to AQ-F [ka]

[0330] 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=1500

[0331] [4] Evaluation of Chemically Amplified Resist Compositions: ArF Lithography Evaluation (1) [Examples 3-1 to 3-7, Comparative Examples 2-1 to 2-6] An antireflective coating solution (ARC29A, manufactured by Nissan Chemical Co., Ltd.) was applied to a silicon substrate and baked at 200°C for 60 seconds to produce an antireflective coating (100 nm thick). Each chemically amplified resist composition (R-1 to R-7, CR-1 to R-6) was spin-coated onto the antireflective coating and baked at 100°C for 60 seconds using a hot plate to produce a resist film with a thickness of 90 nm. The resist film was exposed to a line and space pattern (LS pattern) with on-wafer dimensions of 40 nm line width and 80 nm pitch using an ArF excimer laser scanner (Nikon Corporation, NSR-S610C, NA=1.30, dipole, Cr mask) while varying the exposure dose and focus (exposure dose pitch: 1 mJ / cm). 2 The lithography was performed by immersion lithography (focus pitch: 0.025 μm), and after exposure, PEB was performed for 60 seconds at the temperature shown in Table 4. Water was used as the immersion liquid. Puddle development was then performed for 30 seconds in a 2.38% by mass TMAH aqueous solution, followed by rinsing with pure water and spin drying to obtain a positive pattern. The developed LS pattern was observed using a Hitachi High-Technologies Corporation critical dimension SEM (CG4000), and the sensitivity, exposure latitude (EL), mask error factor (MEF), and LWR were evaluated according to the methods described below. The results are shown in Table 4.

[0332] [Sensitivity evaluation] The optimum exposure dose E for obtaining an LS pattern with a line width of 40 nm and a pitch of 80 nm op (mJ / cm 2 The smaller this value, the higher the sensitivity.

[0333] [EL Rating] The EL (unit: %) was calculated from the exposure amount formed within a range of ±10% (36 to 44 nm) of the 40 nm space width in the LS pattern using the following formula. The larger this value, the better the performance. EL(%)=(|E1-E2| / E op ) x 100 E1: Optimal exposure dose for creating an LS pattern with a line width of 36 nm and a pitch of 80 nm E2: Optimal exposure dose for creating an LS pattern with a line width of 44 nm and a pitch of 80 nm E op : Optimal exposure dose to produce LS pattern with line width of 40nm and pitch of 80nm

[0334] [MEF Rating] Keep the pitch fixed and change the line width of the mask. op The line width of each LS pattern irradiated with 1000 kJ / s was observed. The MEF value was calculated using the following formula from the change in the line width of the mask and the line width of the LS pattern. The closer this value is to 1, the better the performance. MEF = (LS pattern line width / mask line width) - b b: constant

[0335] [LWR rating] E op The dimensions of the LS pattern obtained by irradiation at 10 points in the longitudinal direction of the line were measured, and the LWR was calculated as three times the standard deviation (σ) (3σ). The smaller this value, the less roughness and the more uniform the line width pattern obtained.

[0336] [Table 4]

[0337] The results shown in Table 4 demonstrate that the chemically amplified resist composition containing the amine compound of the present invention exhibits good sensitivity and is also excellent in EL, MEF, and LWR. This demonstrates that the chemically amplified resist composition of the present invention is suitable as a material for ArF immersion lithography.

[0338] [5] Evaluation of Chemically Amplified Resist Compositions: ArF Lithography Evaluation (2) [Examples 4-1 to 4-6, Comparative Examples 3-1 to 3-2] Each chemically amplified resist composition (R-8 to R-13, CR-7 to CR-8) was spin-coated onto a trilayer process substrate having a 180 nm thick spin-on carbon film ODL-180 (carbon content 80% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., and a 35 nm thick silicon-containing spin-on hard mask SHB-A941 (silicon content 43% by mass) formed thereon. The substrate was then baked at 100°C for 60 seconds using a hot plate to form a 100 nm thick resist film. The resist film was exposed to a contact hole pattern (CH pattern) with a wafer dimension of 45 nm and a pitch of 110 nm using an ArF excimer laser immersion scanner (Nikon Corporation, NSR-S610C, NA = 1.30, σ = 0.90 / 0.72, cross-pole aperture 35 degrees, azimuthally polarized illumination, 6% halftone phase shift mask, cross-pole illumination) while varying the exposure dose and focus (exposure dose pitch: 1 mJ / cm 2 After exposure, PEB was performed at the temperature shown in Table 5 for 60 seconds. Water was used as the immersion liquid. Paddle development was then performed with n-butyl acetate for 30 seconds, rinsed with 4-methyl-2-pentanol, and spin-dried to obtain a negative pattern. The developed CH pattern was observed with a Hitachi High-Technologies Corporation critical dimension SEM (CG4000), and the sensitivity, MEF, CDU, and depth of focus (DOF) were evaluated according to the following methods. The results are shown in Table 5.

[0339] [Sensitivity evaluation] The optimum exposure dose E for obtaining a CH pattern with a hole dimension of 45 nm and a pitch of 110 nm op (mJ / cm 2 The smaller this value, the higher the sensitivity.

[0340] [MEF Rating] The pitch is fixed, and the mask dimensions are changed to op The CH patterns irradiated with 1000 uF were observed. The MEF value was calculated from the changes in the mask dimensions and CH pattern dimensions using the following formula. The closer this value is to 1, the better the performance. MEF = (CH pattern dimension / mask dimension) - b b: constant

[0341] [CDU Rating] In the sensitivity evaluation, E op The dimensions of the CH pattern obtained by irradiation at 10 points (9 CH patterns per point) within the same exposure shot were measured, and the CDU was calculated as three times the standard deviation (σ). The smaller this value, the better the dimensional uniformity of the CH pattern.

[0342] [DOF evaluation] For the evaluation of the depth of focus, the focus range formed within a range of ±10% (40.5 to 49.5 nm) of the 45 nm dimension of the CH pattern was determined. The larger this value, the wider the depth of focus.

[0343] [Table 5]

[0344] The results shown in Table 5 demonstrate that the chemically amplified resist composition containing the amine compound of the present invention exhibits good sensitivity and is also excellent in MEF, CDU, and DOF, demonstrating that the chemically amplified resist composition of the present invention is suitable as a material for ArF immersion lithography.

[0345] [6] Evaluation of chemically amplified resist compositions: EUV lithography evaluation [Examples 5-1 to 5-9, Comparative Examples 4-1 to 4-6] Each chemically amplified resist composition (R-14 to R-22, CR-9 to CR-14) was spin-coated onto a Si substrate on which a 20 nm thick silicon-containing spin-on hard mask SHB-A940 (43% silicon by mass) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed, and the substrate was pre-baked at 100°C for 60 seconds using a hot plate to produce a 50 nm thick resist film. The resist film was exposed to an LS pattern with an on-wafer dimension of 18 nm and a pitch of 36 nm using an ASML EUV scanner NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination) while varying the exposure dose and focus (exposure dose pitch: 1 mJ / cm). 2 The exposure was performed with a focus pitch of 0.020 μm, and post-exposure bake (PEB) was performed for 60 seconds at the temperature shown in Table 6. This was followed by puddle development with a 2.38% by mass TMAH aqueous solution for 30 seconds, rinsing with a surfactant-containing rinse solution, and spin drying to obtain a positive pattern. The developed LS pattern was observed with a Hitachi High-Technologies Corporation critical dimension SEM (CG6300), and the sensitivity, EL, LWR, and DOF were evaluated according to the methods described below. The results are shown in Table 6.

[0346] [Sensitivity evaluation] The optimum exposure dose E for obtaining an LS pattern with a line width of 18 nm and a pitch of 36 nm op (mJ / cm 2 ) was calculated and used as the sensitivity.

[0347] [EL Rating] EL (unit: %) was calculated from the exposure amount formed within a range of ±10% (16.2 to 19.8 nm) of the 18 nm space width in the LS pattern using the following formula: The larger this value, the better the performance. EL(%)=(|E1-E2| / E op ) x 100 E1: Optimal exposure dose for LS pattern with line width of 16.2 nm and pitch of 36 nm E2: Optimal exposure dose for LS pattern with line width of 19.8 nm and pitch of 36 nm E op : Optimal exposure dose to produce LS pattern with line width of 18nm and pitch of 36nm

[0348] [LWR rating] E op The dimensions of the LS pattern obtained by irradiation at 10 points in the longitudinal direction of the line were measured, and the LWR was calculated as three times the standard deviation (σ) (3σ). The smaller this value, the less roughness and the more uniform the line width pattern obtained.

[0349] [DOF evaluation] For the evaluation of the depth of focus, the focus range formed within a range of ±10% (16.2 to 19.8 nm) of the 18 nm dimension of the LS pattern was determined. The larger this value, the wider the depth of focus.

[0350] [Table 6]

[0351] The results shown in Table 6 indicate that the chemically amplified resist composition containing the amine compound of the present invention exhibits good sensitivity and excellent EL, LWR, and DOF, demonstrating that the chemically amplified resist composition of the present invention is suitable as a material for EUV lithography.

Claims

1. An amine compound represented by any one of the following formulae AQ-1 to AQ-7. 【Chemistry 1】

2. A chemically amplified resist composition comprising a quencher comprising the amine compound of claim 1.

3. 3. The chemically amplified resist composition according to claim 2, which comprises a base polymer containing a repeating unit represented by the following formula (a1) or (a2): 【Chemistry 2】 (In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X 1 represents a single bond, a phenylene group, a naphthylene group, or *-C(=O)-O-X 11 -, and the phenylene group or naphthylene group may be substituted with a halogen atom or an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom. 11 is a saturated hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the saturated hydrocarbylene group may contain a hydroxy group, an ether bond, an ester bond or a lactone ring. X 2 is a single bond or *-C(=O)-O-. * indicates a bond to a carbon atom in the main chain. R 11 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. AL 1 and AL 2 are each independently an acid labile group. a is an integer from 0 to 4.

4. 4. The chemically amplified resist composition according to claim 3, wherein the base polymer further comprises a repeating unit represented by the following formula (b1) or (b2): 【Transformation 3】 (In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y 1 is a single bond or *-C(=O)-O-. * represents a bond to a carbon atom in the main chain. R 21 is a group having 1 to 20 carbon atoms and containing at least one structure selected from a hydrogen atom, a hydroxy group other than a phenolic 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 acid anhydride (-C(=O)-O-C(=O)-). R 22 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. b is an integer from 1 to 4, and c is an integer from 0 to 4, provided that 1≦b+c≦5.

5. 4. The chemically amplified resist composition according to claim 3, wherein the base polymer further comprises at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (c1) to (c4): 【Chemistry 4】 (In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 is a single bond or a phenylene group. Z 2 is *-C(=O)-O-Z 21 -, *-C(=O)-NH-Z 21 - or *-O-Z 21 - is. Z 21 represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a divalent group obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. Z 3 represents a single bond, a phenylene group, a naphthylene group, or *-C(=O)-O-Z 31 - is. Z 31 is an aliphatic hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the aliphatic hydrocarbylene group may contain a hydroxy group, an ether bond, an ester bond, or a lactone ring. Z 4 is a single bond or **-Z 41 -C(=O)-O-. Z 41 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Z 5 represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-C(=O)-O-Z 51 -, *-C(=O)-N(H)-Z 51 - or *-O-Z 51 - is. Z 51 represents an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group. * represents a bond to a carbon atom in the main chain. ** represents Z 3 Represents a bond with . R 31 and R 32 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 31 and R 32 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached. L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonate ester bond, a carbonate bond or a carbamate bond. Rf 1 and Rf 2 are each independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. 5 and Rf 6 cannot simultaneously become a hydrogen atom. M - is a non-nucleophilic counterion. A + is an onium cation. d is an integer from 0 to 3.

6. 3. The chemically amplified resist composition according to claim 2, further comprising an organic solvent.

7. 3. The chemically amplified resist composition according to claim 2, further comprising a photoacid generator.

8. 3. The chemically amplified resist composition according to claim 2, further comprising a quencher other than the amine compound represented by formula (1).

9. 3. The resist composition according to claim 2, further comprising a surfactant.

10. A pattern forming method comprising the steps of: forming a resist film on a substrate using the chemically amplified resist composition according to claim 2; exposing the resist film to high-energy rays; and developing the exposed resist film using a developer.

11. 11. The pattern forming method according to claim 10, wherein the high-energy beam is a KrF excimer laser beam, an ArF excimer laser beam, an electron beam, or extreme ultraviolet light having a wavelength of 3 to 15 nm.

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