JP2017016053A - Resin composition and manufacturing method of device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition absorbing EUV or electron beam efficiently, low in sensitivity to OoB and having high contrast.SOLUTION: There is provided a resin composition containing a compound represented by the general formula (1) and a compound which reacts with acid. (1). where T is an oxygen atom or a sulfur atom, Ris one of a linear, branched or alicyclic alkyl group which may have a substituent and an aryl group which may have a substituent and Ris one of a hydrogen atom and a linear, branched or alicyclic alkyl group which may have a substituent.SELECTED DRAWING: None

Description

  Some embodiments of the present invention relate to a resin composition. Some embodiments of the present invention also relate to a method for manufacturing a device using the above resin composition.

  In recent years, manufacturing of display devices such as liquid crystal display (LCD) and organic EL display (OLED) and formation of semiconductor elements have been actively performed by making full use of photolithography technology using a photoresist. In the above-mentioned electronic parts and electronic product packages, light such as i-line having a wavelength of 365 nm, h-line (405 nm) and g-line (436 nm) having a longer wavelength is widely used as an active energy ray. Therefore, various photoacid generators are known as photoacid generators exhibiting high sensitivity in the wavelength region from long-wavelength ultraviolet light to visible light (see Patent Document 1). The photoacid generator is a photosensitizer having a function of generating an acid when irradiated with light.

  In recent years, devices have been highly integrated and demands for miniaturization of lithography technology have increased. KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), extreme ultraviolet light (EUV, wavelength 13.5 nm), and electrons Light with a very short wavelength such as a line (EB) tends to be used for exposure. Since the lithography technology using light with a short wavelength, particularly EUV or electron beam, can be manufactured by single patterning, the necessity of a photoacid generator exhibiting high sensitivity to EUV or electron beam is It is expected to increase further in the future.

Japanese Patent Laid-Open No. 11-7124

EUV generated by an LPP (Laser Produced Plasma) light source, which is currently mainstream, has a spectral peak at 13.5 nm, but other than the 13.5 nm band called out-of-band (hereinafter also referred to as “OoB”). It is known that light in the near infrared region (190 to 300 nm) is also emitted from vacuum ultraviolet rays.
In developing resists for EUV lithography technology, one of the important issues is how to improve the acid generation efficiency of the photoacid generator to obtain contrast. In addition, reducing outgas generated during exposure is also an important issue in lithography technology.

  In EUV lithography, not only the EUV or electron beam absorption and acid generation efficiency are increased, but also high sensitivity can be obtained by reducing the sensitivity to simultaneously generated OoB. However, since conventional photoacid generators are sensitive to OoB, there is a problem in obtaining good contrast. Further, there is a problem in that a low molecular compound generated by decomposition generates outgas.

As a result of intensive studies to solve the above problems, the present inventors have found that a resin composition using a compound having a specific structure as a photoacid generator is sensitive to OoB when used as a resist resin composition for EUV lithography. It has been found that the outgas generated during exposure can be reduced, and the present invention has been completed.
That is, the resin composition according to one embodiment of the present invention includes a compound represented by the following general formula (1) and a compound that reacts with an acid.

(In the above formula (1), T is an oxygen atom or a sulfur atom; R ¹ has a linear, branched or alicyclic alkyl group which may have a substituent, and a substituent. R ² is any of a hydrogen atom and a linear, branched or alicyclic alkyl group which may have a substituent; R ³ each hydrogen atom to R ^5, hydroxy groups, be any selected from the group consisting of organic group of a thiol group and having 1 to 20 carbon atoms; each of n ₁ and n ₂ is an integer from 0 to 2 , _{n 3} is an integer of 2 to 4, n ₄ when both n ₁ and n ₂ is 0 is 4, when the other in one of n ₁ and n ₂ are 0 is 1 to 2 _{n 4} Is 2 and n ₅ or n ₆ is 4 to 6, n ₄ is 0 when n ₁ and n ₂ are 1 to 2, and n ₅ and n ₆ are each 4 to 6; X ⁻ is monovalent Anion Show.)

  One aspect of the present invention includes a coating film forming step of forming a coating film on a substrate using the resin composition, a photolithography step of exposing the coating film in a pattern using an active energy ray, And a pattern forming step of obtaining a photoresist pattern by developing the exposed coating film.

  Since the resin composition according to some embodiments of the present invention efficiently absorbs EUV or electron beam among active energy rays and contains a compound having low sensitivity to OoB as a photoacid generator, EUV High contrast can be achieved when used as a lithographic resist composition. Moreover, the resin composition which concerns on some aspects of this invention can reduce the outgas generated at the time of exposure of an active energy ray.

Hereinafter, although this invention is demonstrated concretely, this invention is not limited to this.
<1> Resin Composition A resin composition according to one embodiment of the present invention includes a compound represented by the general formula (1) (hereinafter, also referred to as “compound (1)”), a compound that reacts with an acid, , Including.
(Compound represented by the above general formula (1))
First, the compound (1) will be described.

In the above formula (1), T is an oxygen atom or a sulfur atom; R ¹ has a linear, branched or alicyclic alkyl group which may have a substituent, and a substituent. R ² is any one of a hydrogen atom and a linear, branched or alicyclic alkyl group which may have a substituent; R ³ to Each of R ⁵ is any one selected from the group consisting of a hydrogen atom, a hydroxy group, a thiol group and an organic group having 1 to 20 carbon atoms; each of n ₁ and n ₂ is an integer of 0 to ₂ ; n ₃ is an integer of 2 to 4, n ₄ when both n ₁ and n ₂ is 0 is 4, _{n 4} when the other is 1-2 with either n ₁ and n ₂ is 0 2 and n ₅ or n ₆ are 4 to 6, n ₁ and n ₂ are 1 to 2, n ₄ is 0 and n ₅ and n ₆ are each 4 to 6; X ⁻ is a monovalent anion Show The

Specific examples of the linear, branched or alicyclic alkyl group for R ¹ include methyl, ethyl, n-propyl, n-butyl, isopropyl, t-butyl, cyclopropyl group, cyclobutyl group and cyclopentyl group, respectively. Alkyl groups such as cyclohexyl group, adamantane-1-yl group, adamantane-2-yl group, norbornan-1-yl group and norbornan-2-yl group.
In the alkyl group of R ¹ , —O—, —CO—, —COO—, —OCO—, —O—CO—O—, —NHCO—, —CONH—, —NH are substituted for at least one carbon atom. From the group consisting of —CO—O—, —O—CO—NH—, —NH—, —N (R ⁶ ) —, —N (Ar ¹ ) —, —S—, —SO— and —SO ₂ —. One type of hetero atom-containing group selected may be included in the skeleton. R ⁶ and Ar ¹ will be described later.

Specifically, the aryl group for R ¹ is an aromatic hydrocarbon group; and any one selected from an oxygen atom, a nitrogen atom, and a sulfur atom in place of at least one carbon atom of the aromatic hydrocarbon group And aromatic heterocyclic groups contained in the skeleton.

Examples of the aromatic hydrocarbon group for R ¹ include a monocyclic aromatic hydrocarbon group and a condensed polycyclic aromatic hydrocarbon group in which the monocyclic aromatic hydrocarbon is condensed at least two rings. These aromatic hydrocarbon groups may have a substituent.
Examples of the monocyclic aromatic hydrocarbon group include groups having a skeleton such as benzene.
Examples of the condensed polycyclic aromatic hydrocarbon group include groups having a skeleton such as indene, naphthalene, azulene, anthracene, and phenanthrene.

Examples of the monovalent aromatic heterocyclic group represented by R ^{1 in} the general formula (1) include a monocyclic aromatic heterocyclic group, and at least one of the monocyclic aromatic heterocyclic rings is the above aromatic hydrocarbon group or aliphatic group. And a condensed polycyclic aromatic heterocyclic group condensed with an aromatic heterocyclic group. These aromatic heterocyclic groups may have a substituent.

Examples of the monocyclic aromatic heterocyclic group include groups having a skeleton such as furan, pyrrole, imidazole, pyran, pyridine, pyrimidine, and pyrazine.
Examples of the condensed polycyclic aromatic heterocyclic group include groups having a skeleton such as indole, purine, quinoline, isoquinoline, chromene, phenoxazine, xanthene, acridine, phenazine and carbazole.

Examples of the substituent that R ¹ may have include a hydroxy group, a carboxy group, a carbonyl group, an alkoxy group (—OR ⁶ ), an acyl group (—COR ⁶ ), an alkoxycarbonyl group (—COOR ⁶ ), an aryl group ( -ar ^1), an aryloxy group (-OAr ^1), an amino group, an alkylamino group (-NHR ^6), dialkylamino group _{^{(-N (R 6) 2)}} , an arylamino group (-NHAr ^1), diarylamino groups (—N (Ar ¹ ) ₂ ), N-alkyl-N-arylamino group (—NR ⁶ Ar ¹ ) phosphino group, silyl group, halogen atom, trialkylsilyl group (—Si— (R ⁶ ) ₃ ), at least one silyl group substituted with Ar ¹ alkyl group of the trialkylsilyl group, an alkylthio group (-SR ⁶⁾ and an arylthio group (-SAr ¹⁾ or the like and the like Kill, but are not limited to these.

R ⁶ is preferably an alkyl group having 1 or more carbon atoms. Specific examples of the alkyl group having 1 or more carbon atoms include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group and n-decyl group. Linear alkyl groups such as isopropyl groups, isobutyl groups, tert-butyl groups, isopentyl groups, tert-pentyl groups, 2-ethylexyl groups, etc .; cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, cyclohexyl groups Alicyclic alkyl groups such as adamantane-1-yl group, adamantane-2-yl group, norbornan-1-yl group and norbornane-2-yl group; one of these hydrogens is trimethylsilyl group, triethylsilyl group and dimethyl group A silyl group-substituted alkyl group substituted with a trialkylsilyl group such as an ethylsilyl group; An alkyl group in which at least one of the children is substituted with a cyano group or a fluoro group is preferred.

Ar ¹ in the above substituent is preferably an aryl group. Specific examples of the aryl group of Ar ¹ include phenyl group, biphenyl group, terphenyl group, quaterphenyl group, naphthyl group, anthryl group, phenanthrenyl group, pentarenyl group, indenyl group, indacenyl group, acenaphthyl group, fluorenyl group. , Heptalenyl group, naphthacenyl group, pyrenyl group, chrysenyl group, tetracenyl group, furanyl group, thienyl group, pyranyl group, thiopyranyl group, pyrrolyl group, imidazolyl group, oxazolyl group, thiazolyl group, pyrazoyl group, pyridyl group, pyridyl group, isobenzofuran Nyl group, benzofuranyl group, isochromenyl group, chromenyl group, indolyl group, isoindolyl group, benzoimidazolyl group, xanthenyl group, aquadinyl group, carbazoyl group and the like are preferable.

The alkyl group for R ¹ preferably has 1 to 20 carbon atoms, more preferably 1 to 12 and even more preferably 1 to 6. The aryl group for R ¹ preferably has 1 to 12 carbon atoms, and more preferably has 1 to 10 carbon atoms. When R ¹ has a benzene ring, the number of benzene rings is preferably 2 or less.
When R ¹ has a substituent, the number of carbon atoms including the carbon number of the substituent is preferably the above.
As R ¹ , among the alkyl group which may have a substituent and the aryl group which may have a substituent, an alkyl group containing a hetero atom-containing group in the skeleton from the viewpoint of improving electron acceptability, In addition, an aryl group is preferable, and an aryl group is more preferable from the viewpoint of improving electron acceptability and increasing stability of the onium salt. From the viewpoint of reducing the molar absorption coefficient of 193 nm, a naphthyl group is particularly preferable.

Examples of the linear, branched or alicyclic alkyl group for R ² include the same as those for R ¹ . Examples of the substituent that R ² may have include the same substituents as those described above for R ¹ .
R ² is preferably a hydrogen atom and an alkyl group which may have a substituent. Among the alkyl groups that may have a substituent, an alkyl group containing a hetero atom-containing group in the skeleton is preferable from the viewpoint of improving electron acceptability.

Examples of the organic group having 1 to 20 carbon atoms of R ^{3 to} R ⁵ include an electron donating group and an electron withdrawing group having 1 to 20 carbon atoms.
Examples of the electron donating group include an alkyl group, an alkoxy group, an alkylthio group, and an alkenyl group. Examples of the alkyl group contained in the electron donating group are the same as those described above for R ¹ . The alkenyl group contained in the electron donating group is, for example, one in which at least part of the carbon-carbon single bond of the alkyl group contained in the electron donating group is a carbon-carbon double bond.
When R ^{3 to} R ⁵ are electron donating groups, the substitution position of R ^{3 to} R ^{5 is} the position of “◯” as shown by the following formula (2), thereby enhancing the reaction selectivity in the synthesis of sulfonium salt. This is preferable.

Examples of the electron withdrawing group include an alkylcarbonyl group, an alkenylcarbonyl group, an alkylcarbonyloxy group, an alkenylcarbonyloxy group, an alkyloxycarbonyloxy group, an alkenyloxycarbonyloxy group, an alkylsulfonyl group, an alkenylsulfonyl group, and an alkylsulfonyloxy group. Alkenylsulfonyloxy group, alkylcarbonylamino group, alkenylcarbonylamino group and the like. Examples of the alkyl group contained in the electron-withdrawing group are the same as those for R ¹ . The alkenyl group contained in the electron withdrawing group is, for example, one in which at least a part of the carbon-carbon single bond of the alkyl group contained in the electron withdrawing group is a carbon-carbon double bond.
When R ^{3 to} R ⁵ are electron-withdrawing groups, the substitution positions of R ^{3 to} R ⁵ are not particularly limited.

It is preferable that R ^{3 to} R ⁵ are electron-withdrawing groups because electron acceptability is improved and sensitivity to EUV and electron beams is increased.
R ^{3 to} R ⁵ may be an aryl group. Examples of the aryl group for R ^{3 to} R ⁵ include the same groups as those described above for R ¹ . Of the aryl groups represented by R ^{3 to} R ⁵ , a naphthyl group is preferable.

In the general formula (1), it is preferable that either n ¹ or n ² is 0 and the other is 1. Thereby, the compound (1) has at least one naphthalene ring. The compound (1) can reduce the molar extinction coefficient at 193 nm by having at least one naphthalene ring in the molecule. Therefore, it is preferable that one or more naphthalene rings are present in the molecule.
Moreover, at least any one of R ^{3 to} R ⁵ may have a polymerizable group such as an acryloyl group and a methacryloyl group.

The compound (1) preferably has a molar extinction coefficient at 193 nm of 4.0 × 10 ⁻³ [cm ² / mol] or less, and is 2.0 × 10 ⁻³ [cm ² / mol] or less. Is more preferable. Thereby, the sensitivity can be reduced with respect to OoB. In order to set the molar extinction coefficient of the compound (1) within the above range, the structure as described above may be used.

  The compound (1) has a ring structure formed by a sulfur atom serving as a cation center and an oxygen atom represented by T or another sulfur atom (hereinafter also referred to as “S-containing ring structure”) in the cation portion. And the S-containing ring structure has a condensed ring structure that is not condensed with two or more aromatic rings, so that EUV or an electron beam is used as an active energy ray and one molecular state is maintained even when OoB is emitted Is less sensitive to OoB.

More details are as follows. In the compound (1), at least two S ⁺ -C bonds in the condensed ring structure of the cation moiety are present in the S-containing ring structure. Therefore, if OoB is emitted when EUV or an electron beam is used as an active energy ray, even if one of the S ⁺ -C bonds in the S-containing ring structure is broken, the remaining one exists. , It is possible to maintain a single molecular state even after the OoB irradiation, the cation portion is difficult to decompose. Thereby, even after OoB irradiation, the molecular weight is not reduced and it is difficult to outgas.

Moreover, the said compound (1) is preferable from generating the outgas at the time of exposure by setting the molecular weight of a cation part to become 200 or more.
Specific examples of the cation moiety of the compound (1) include the structures shown below. In the following examples, examples of T = oxygen atom are mainly disclosed, but a sulfur atom may be used instead of an oxygen atom.

Specific examples of the anion X ⁻ of the compound (1) include an alkylsulfonic acid anion, an arylsulfonic acid anion, a bisalkylsulfonylamide anion, a trisalkylsulfonylmethide anion, and at least one hydrogen atom thereof has fluorine. Preferable examples include anions selected from the group consisting of compounds substituted with atoms.
Examples of the alkyl group and aryl group that the anion has are the same as those described above for R ⁶ and Ar ¹ .

(Method for producing the compound represented by the general formula (1))
The compound (1) can be synthesized, for example, as follows. However, the production method of the compound (1) according to the present invention is not limited to this.
When n ₃ of the compound (1) is 2 and R ¹ is an ethyl group, 2-mesyloxydiethyl sulfide is first synthesized from 2- (ethylthio) ethanol and methanesulfonyl chloride. The obtained 2-mesyloxydiethyl sulfide is oxidized to obtain 2-mesyloxydiethylsulfoxide, which can be obtained by reacting with an aryl alcohol derivative or an aryl thiol derivative.

When n ₃ of the compound (1) is 2 and R ¹ is a phenyl group, first, 2-mesyloxyethyl-phenyl sulfide is synthesized from 2-hydroxyethyl-phenyl sulfide and methanesulfonyl chloride. The obtained 2-mesyloxyethyl-phenyl sulfide is oxidized to obtain 2-mesyloxyethyl-phenyl sulfoxide, which can be obtained by reacting with an aryl alcohol derivative or an aryl thiol derivative.
Specifically, it will be described in Examples.

(Compound reacting with acid)
The compound that reacts with an acid preferably has a protecting group that is deprotected with an acid, is polymerized with an acid, or is crosslinked with an acid. That is, the compound that reacts with an acid is at least selected from the group consisting of a compound having a protecting group that is deprotected by an acid, a compound having a polymerizable group that is polymerized by an acid, and a crosslinking agent having a crosslinking action by an acid. Either is preferable.

  The compound having a protecting group that is deprotected by an acid is a compound whose solubility in a developer is changed by deprotecting the protecting group by an acid. For example, in the case of aqueous development using an alkali developer or the like, it is insoluble in the alkali developer, but the protecting group is deprotected in the exposed area by the acid generated from the compound (1) upon exposure, whereby an alkali developer. It is a compound that becomes soluble in.

  In the present invention, the developer is not limited to an alkaline developer, and may be a neutral developer or an organic solvent development. Therefore, when an organic solvent developer is used, the compound having a protective group that is deprotected by an acid is deprotected in the exposed area by the acid generated from the compound (1) upon exposure, and the organic solvent developer is converted into an organic solvent developer. On the other hand, it is a compound whose solubility is lowered.

Specific examples of the protecting group to be deprotected with an acid include an ester group, an acetal group, a tetrahydropyranyl group, a carbonate group, a siloxy group, and a benzyloxy group. As the compound having the protecting group, a compound having a styrene skeleton, a methacrylate or an acrylate skeleton pendant with these protecting groups is preferably used.
The compound having a protecting group to be deprotected with an acid may be a protecting group-containing low molecular weight compound or a protecting group-containing polymer component. In the present invention, the low molecular weight compound has a weight average molecular weight of less than 2000, and the polymer component has a weight average molecular weight of 2000 or more.

The compound having a polymerizable group that is polymerized with an acid is a compound that changes the solubility in a developer by polymerizing with an acid. For example, in the case of aqueous development, it acts on a compound that is soluble in an aqueous developer and lowers the solubility of the compound in the aqueous developer after polymerization. Specific examples include compounds having an epoxy group, an acetal group, a vinyloxy group, an oxetanyl group, and the like.
The compound having a polymerizable group that is polymerized with an acid may be a polymerizable low-molecular compound or a polymerizable polymer component.

A crosslinking agent having a crosslinking action with an acid is a compound that changes the solubility in a developer by crosslinking with an acid. For example, in the case of aqueous development, it acts on a compound that is soluble in an aqueous developer, and lowers the solubility of the compound in the aqueous developer after polymerization or crosslinking. Specific examples include a crosslinking agent having an epoxy group, an acetal group, a vinyloxy group, a 1-alkoxyamino group, an oxetanyl group, and the like. When the compound is a cross-linking agent having a cross-linking action, examples of the cross-linking partner compound, that is, a compound that reacts with the cross-linking agent and changes its solubility in a developing solution include compounds having a phenolic hydroxyl group.
The compound having a crosslinking action with an acid may be a polymerizable low molecular compound or a polymerizable polymer component.

(Resin composition)
Specific examples of the resin composition according to one embodiment of the present invention include the following.
Resist composition comprising a compound having a protecting group to be deprotected by the acid and the compound (1); Resist composition comprising a compound having a polymerizable group to be polymerized by the acid and the compound (1); A resist composition comprising a crosslinking agent having a crosslinking action, a compound that reacts with the crosslinking agent to change the solubility in a developer, and the compound (1).

  The content of the compound (1) in the resist composition of one embodiment of the present invention is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the resist composition component excluding the compound (1). More preferably, it is -15 mass parts, More preferably, it is 5-8 mass parts, It is especially preferable that it is 2-5 mass parts. By containing the compound (1) as a photoacid generator within the above range in the resin composition, a high contrast can be obtained when used as a resist composition for EUV, and further, an outgas generated during exposure. Can be suppressed.

  In addition, although the said compound (1) may be used by itself as a low molecular weight component, when the said compound (1) has a polymeric group, you may superpose | polymerize with another monomer component and use it as a polymer component. . Specifically, examples of the other monomer component include a compound having a protective group to be deprotected and a compound having a polymerizable group that is polymerized with an acid. These, the above compound (1), and optionally other monomer components May be polymerized as a constituent component of the polymer and used as a polymer component.

In any embodiment, the resin composition of one embodiment of the present invention may be blended with other components as long as the effects of the present invention are not impaired. Examples of components that can be blended include the above polymer components, and known additives such as known photoacid generators other than the above compound (1), sensitizers, quenchers such as trioctylamine, surfactants, At least one selected from fillers, pigments, antistatic agents, flame retardants, light stabilizers, antioxidants, ion scavengers, solvents and the like may be added. Is mentioned.
The method for preparing the resin composition of one embodiment of the present invention is not particularly limited, and is prepared by a known method such as mixing, dissolving, or kneading the compound (1), the compound that reacts with the acid, and other optional components. can do.

<5> Device Manufacturing Method One embodiment of the present invention includes a coating film forming step of forming a coating film on a substrate using a resin composition containing the compound (1).
A photolithographic step of exposing the coating film in a pattern using an active energy ray;
And a pattern forming step of obtaining a photoresist pattern by developing the exposed coating film.

The active energy ray used for exposure in the photolithography step may be any light that can activate the compound (1) to generate an acid, such as UV, visible light, X-ray, electron beam, ion beam, i-line, And EUV etc. are meant. Since the compound (1) according to one embodiment of the present invention has high sensitivity to EUV and electron beam, the active energy ray is preferably EUV or electron beam.
The amount of light irradiation varies depending on the type and mixing ratio of each component in the resin composition, the film thickness of the coating film, and the like, but is preferably 1 J / cm ² or less or 100 μC / cm ² or less.

  Hereinafter, some embodiments of the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

<Synthesis of Compound A>
Synthesis Example 1 Synthesis of 2-mesyloxydiethyl sulfide

  10 g of 2- (ethylthio) ethanol and 11.5 g of methanesulfonyl chloride are dissolved in 50 g of acetonitrile to 10 ° C. To this, 11.8 g of triethylamine is added dropwise and stirred at 25 ° C. for 2 hours. After stirring, 50 g of pure water is added and the mixture is further stirred for 10 minutes, and then acetonitrile is distilled off. The residue is extracted with 50 g of ethyl acetate, and the organic layer is washed with 30 g of pure water. The recovered organic layer is distilled off to obtain 11.2 g of a liquid containing 2-mesyloxydiethyl sulfide.

Synthesis Example 2 Synthesis of 2-mesyloxydiethyl sulfoxide

  10 g of the liquid containing 2-mesyloxydiethyl sulfide obtained in Synthesis Example 1 is dissolved in 30 g of methanol. To this, 4.7 g of 35% hydrogen peroxide water is added and stirred for 2 hours. After separating and washing twice with 30 g of hexane, the methanol layer is recovered and the solvent is distilled off. The residue is redissolved in 60 g of acetone, and 6.0 g of anhydrous sodium sulfate is added and stirred. By filtering this and distilling off acetone, 6.6 g of a liquid containing 2-mesyloxydiethyl sulfoxide is obtained.

Synthesis Example 3 Synthesis of ethyl-1,2-naphthoxathianium nonafluorobutanesulfonate (Compound A)

  Dissolve 6.0 g of the liquid containing 2-mesyloxydiethyl sulfoxide obtained in Synthesis Example 2 above, 4.7 g of 2-hydroxynaphthalene, and 10.2 g of methanesulfonic acid in 24 g of acetonitrile. To this, 1.9 g of phosphorus pentoxide is added and stirred for 15 hours. Thereafter, 60 g of pure water is added and stirred for 10 minutes. To this, 9.0 g of potassium nonafluorobutanesulfonate and 60 g of methylene chloride are added, and the mixture is further stirred for 1 hour. After liquid separation, the organic layer was washed 4 times with 30 g of pure water, and then methylene chloride was distilled off. The residue is purified by silica gel column chromatography (methylene chloride / methanol = 90/10 (volume ratio)) to obtain 4.3 g of ethyl-1,2-naphthoxathianium nonafluorobutanesulfonate.

<Synthesis of Compound B>
Synthesis Example 4 Synthesis of ethyl-1,2- (7-hydroxy) naphthoxathianium nonafluorobutanesulfonate (Compound B)

  Ethyl-1,2- (7-hydroxy) naphthoxathianium nonafluorobutanesulfonate was obtained by performing the same operation as in Synthesis Example 3 except that 2,7-dihydroxynaphthalene was used instead of 2-hydroxynaphthalene. 3.4 g of oil containing is obtained.

<Synthesis of Compound C>
(Synthesis Example 5) Synthesis of ethyl-1,2- (7-acetoxy) naphthoxathianium nonafluorobutanesulfonate (Compound C)

  Ethyl-1,2- (7-hydroxy) naphthoxythianium nonafluorobutanesulfonate (3.0 g) and acetic anhydride (0.74 g) are dissolved in methylene chloride (24 g) to 25 ° C. To this, 0.58 g of pyridine is added dropwise over 10 minutes. After dropping, the mixture is stirred at 25 ° C. for 2 hours. Thereafter, 12 g of pure water is added and stirred for another 10 minutes. The organic layer is collected, washed with water 3 times using 12 g of pure water, and then the solvent is distilled off. The residue is purified by silica gel column chromatography (methylene chloride / methanol = 90/10 (volume ratio)) to obtain 2.2 g of ethyl-1,2- (7-acetoxy) naphthoxathianium nonafluorobutanesulfonate. .

<Synthesis of Compound D>
Synthesis Example 6 Synthesis of 4- (2-hydroxyethyl) thioacetophenone

  10 g of 2- (ethylthio) ethanol, 15.2 g of 4-fluoroacetophenone, and 11.5 g of potassium carbonate are dissolved in 50 g of DMF to 100 ° C. This is stirred for 2 hours. After stirring, 100 g of pure water is added and stirred for another 10 minutes. Extract with 80 g of ethyl acetate, and wash the organic layer with 40 g of pure water. Thereafter, the solvent of the collected organic layer is distilled off. This is purified by silica gel column chromatography (ethyl acetate / hexane = 30/70 (volume ratio)) to obtain 14.2 g of 4- (2-hydroxyethyl) thioacetophenone.

Synthesis Example 7 Synthesis of 4- (2-mesyloxyethyl) thioacetophenone

  An oily substance containing 4- (2-mesyloxyethyl) thioacetophenone by performing the same operation as in Synthesis Example 1 except that 4- (2-hydroxyethyl) thioacetophenone is used instead of 2- (ethylthio) ethanol. 9.4 g is obtained.

Synthesis Example 8 Synthesis of 4- (2-mesyloxyethyl) sulfinylacetophenone

  An oil containing 4- (2-mesyloxyethyl) sulfinylacetophenone by performing the same operation as in Synthesis Example 2 except that 4- (2-mesyloxyethyl) thioacetophenone is used instead of 2-mesyloxydiethyl sulfide. 9.4 g of product are obtained.

Synthesis Example 9 Synthesis of 4-acetylphenyl-1 ′, 2′-naphthoxathianium nonafluorobutanesulfonate (Compound D)

  4-acetylphenyl-1 ′, 2′-naphthoxa is obtained by performing the same operation as in Synthesis Example 3 except that 4- (2-mesyloxyethyl) sulfinylacetophenone is used instead of 2-mesyloxydiethyl sulfoxide. 5.2 g of thianium nonafluorobutane sulfonate are obtained.

<Synthesis of Compound E>
Synthesis Example 10 Synthesis of 2-hydroxyethyl-phenyl sulfide

  The same operation as in Synthesis Example 6 is performed except that 2-bromoethanol is used instead of 2- (ethylthio) ethanol, thiophenol is used instead of 4-fluoroacetophenone, and the reaction temperature is changed from 110 ° C. to 60 ° C. This gives 10.2 g of 2-hydroxyethyl-phenyl sulfide.

Synthesis Example 11 Synthesis of 2-mesyloxyethyl-phenyl sulfide

  10.2 g of an oily substance containing 2-mesyloxyethyl-phenyl sulfide is obtained by performing the same operation as in Synthesis Example 2 except that 2-hydroxyethyl-phenyl sulfide is used in place of 2- (ethylthio) ethanol. .

Synthesis Example 12 Synthesis of 2-mesyloxyethyl-phenyl sulfoxide

  7.2 g of an oil containing 2-mesyloxyethyl-phenyl sulfoxide was obtained by performing the same operation as in Synthesis Example 2 except that 2-mesyloxyethyl-phenyl sulfide was used instead of 2-mesyloxydiethyl sulfide. obtain.

Synthesis Example 13 Synthesis of phenyl-1,2- (4-methoxy) phenoxathianium nonafluorobutanesulfonate (Compound E)

  Phenyl-1,2- (4-methoxy) phenoxathianium nona is obtained by performing the same operation as in Synthesis Example 3 except that 2-mesyloxyethyl-phenyl sulfoxide is used instead of 2-mesyloxydiethyl sulfoxide. 5.2 g of fluorobutane sulfonate are obtained.

<Preparation of copolymer synthesis>
Synthesis Example 14 Synthesis of Copolymer A α-Methacryloxy-γ-butyrolactone 5.0 g, 2-methyladamantane-2-methacrylate 6.0 g, 3-hydroxyadamantane-1-methacrylate 4.3 g, Deoxygenate by dissolving 0.51 g of dimethyl-2,2′-azobis (2-methylpropionate) in 26 g of propylene glycol-1-monomethyl ether acetate (PGMEA). This is dripped in 7.5 g of PGMEA previously heated at 85 degreeC over 4 hours. After stirring for 2 hours, cool. It reprecipitates by dripping at 180 g of hexane after cooling. This is filtered, filtered and washed again with 70 g of hexane, and then vacuum dried to obtain 8.5 g of copolymer A represented by the following formula as a compound that reacts with an acid.

<Preparation of resin composition>
A resin composition sample 1 is prepared by dissolving 600 mg of the copolymer A and 0.048 mmol of the compound A in 8 ml of cyclohexanone.

<Electron beam sensitivity evaluation>
The sample 1 is spin-coated on a silicon wafer previously modified with hexamethylene disilazane at 2000 rpm for 20 seconds. This is pre-baked on a hot plate at 110 ° C. for 1 minute to obtain a substrate on which a coating film having a thickness of 500 nm is formed. On the coating film of the substrate, an electron beam drawing apparatus (JSM-6500F, manufactured by JEOL Ltd.) is used to draw with a 30 keV electron beam so as to form a 2 μm line and space pattern. The substrate after irradiation was post-baked on a hot plate at 120 ° C. for 1 minute, developed with a 2.38 mass% tetramethylammonium aqueous solution for 1 minute, and then rinsed with pure water to 2 μm. Get a line and space pattern. The irradiation dose at this time is set to E ₀ 1 [μC / cm ² ], and the sensitivity by electron beam irradiation is obtained. The results are shown in Table 1.

<Evaluation of UV sensitivity>
A substrate on which a coating film is formed is prepared in the same manner as the electron beam sensitivity evaluation. An exposure apparatus (HMW-661C-) applies light having a transmission wavelength of 254 nm ± 5 nm to a coating film on the substrate through a 254 nm band-pass filter through a high-pressure mercury lamp so as to form a 100 μm line and space pattern through a photomask. 3. Irradiation using (Oak Manufacturing Co., Ltd.). The substrate after irradiation was developed using a 2.38 mass% tetramethylammonium aqueous solution, and then rinsed with pure water to obtain a 100 μm line and space pattern. Sensitivity is obtained with the irradiation amount at this time as E ₀ 2. The results are shown in Table 1.

<Molar extinction coefficient measurement>
15.0 mg of the above compound A is diluted to 25 ml with acetonitrile using a 25 ml volumetric flask. Take 0.5 ml of the compound A-containing solution with a whole pipette and dilute to 5 ml with acetonitrile using a 5 ml volumetric flask. By measuring the absorption spectrum of the obtained solution using an ultraviolet-visible light spectrophotometer (U-3300, manufactured by Hitachi High-Technologies Corporation), the molar extinction coefficient [mol / cm ² ] of 193 nm and 254 nm is obtained. Ask. The results are shown in Table 1.

Comparative Example 1

  Resin composition sample 2 is prepared in the same manner as in Example 1 except that 2-methoxynaphthyldiethylsulfonium-nonaflate (compound F) represented by the following formula is used in place of compound A. Evaluation of the molar extinction coefficient of the compound F and the electron beam sensitivity and UV sensitivity of the obtained sample 2 is performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2

  Resin composition sample 3 is prepared in the same manner as in Example 1 except that phenylthioxonium-nonaflate (compound G) represented by the following formula is used in place of compound A. Evaluation of the molar extinction coefficient of the compound G and the electron beam sensitivity and UV sensitivity of the obtained sample 3 are carried out in the same manner as in Example 1. The results are shown in Table 1.

Compound A used in Example 1 has the same molecular structure as Compound F used in Comparative Example 1 except for the presence or absence of a condensed ring structure containing an S-containing ring structure. As shown in Table 1, the sensitivity E ₀ 1 of the compound A in the electron beam sensitivity rating is the sensitivity E ₀ 1 the same level of compound F. Further, the compound A and compound F, but not large difference in molar extinction coefficient at 254 nm, in the UV sensitivity evaluation using UV at 254 nm, E ₀ 2 of Compound A compared to E ₀ 2 of Compound F And 2.5 times lower.

It is considered that the difference in sensitivity E ₀ 2 between compound A and compound F is caused by a difference in acid generation mechanism. In the case of electron beam irradiation, it proceeds by a mechanism in which electrons generated by ionizing the polymer component in the resist by electron beam irradiation adhere to the acid generator. In this case, since one cation is received and the cation is reductively converted into a radical and cleaved, the reaction proceeds and acid is generated without recombining reversibly after the cleavage and returning to the cation. Therefore, Compound A and Compound F, which have substantially the same electron accepting property, show the same sensitivity E ₀ 1. On the other hand, when UV is used, after the molecule absorbs light and transitions to an excited state, the S—C bond is cleaved into homolysis or heterolysis without transferring electrons to the outside, and then the cleaved fragment is secondary. Acid is generated by the mechanism causing the reaction. In this case, even after cleavage, a reverse reaction such as recombination occurs with a certain probability, and no acid is generated when deactivated by returning to the cation. Therefore, since compound A has a condensed ring structure containing an S-containing ring structure in the cation moiety, the two fragments remain in close proximity even when one of the S ⁺ -C bonds in the S-containing ring structure is cleaved. It is easy to recombine, the rate of deactivation without generating an acid is increased, and the acid generation efficiency in UV is lowered and the sensitivity E ₀ 2 is lower than that of the compound F having no condensed ring structure including an S-containing ring structure. It is thought to decline. This property is effective, for example, for EUV lithography that wants to suppress acid generation by UV.

Compound G has a different ring structure from Compound A. That is, Compound G has an S-containing ring structure fused with two aromatic rings. Compound G is slightly inferior to Compound A in the electron beam sensitivity evaluation. However, although Compound G had a molar extinction coefficient at 254 nm smaller than that of Compound A, it was about 1.5 times as sensitive as Compound A in the UV sensitivity evaluation.
In compound G, since the S-containing ring structure is condensed with two aromatic rings, the active species generated by cleavage of the S ⁺ -C bond is likely to undergo a transfer reaction, and the acid generation efficiency is higher than that of compound A. Presumed to be.

  Compound G has a molar absorption coefficient of about 193 nm that is about 4 times larger than that of Compound A, so that the decomposition efficiency by 193 nm light is very high. Compound A containing an S-containing ring structure and having a condensed ring structure in which the S-containing ring structure is not condensed with two or more aromatic rings can suppress exposure to ultraviolet rays of 193 nm. Therefore, it can be said that a high-contrast latent image can be obtained by using a resin composition containing Compound A, for example, as a resist composition for lithography using EUV containing 193 nm ultraviolet rays.

  According to some embodiments of the present invention, it is possible to provide a resin composition that efficiently absorbs EUV or an electron beam and has low sensitivity to OoB and high contrast. Moreover, the resin composition which concerns on some aspects of this invention can reduce the outgas generated at the time of exposure.

Claims (9)

A resin composition comprising a compound represented by the following general formula (1) and a compound that reacts with an acid.
(In the formula (1), T is an oxygen atom or a sulfur atom; R ¹ has a linear, branched or alicyclic alkyl group which may have a substituent, and a substituent. R ² is any of a hydrogen atom and a linear, branched or alicyclic alkyl group which may have a substituent; R ³ each hydrogen atom to R ^5, hydroxy groups, be any selected from the group consisting of organic group of a thiol group and having 1 to 20 carbon atoms; each of n ₁ and n ₂ is an integer from 0 to 2 , _{n 3} is an integer of 2 to 4, n ₄ when both n ₁ and n ₂ is 0 is 4, when the other in one of n ₁ and n ₂ are 0 is 1 to 2 _{n 4} Is 2 and n ₅ or n ₆ is 4 to 6, n ₄ is 0 when n ₁ and n ₂ are 1 to 2, and n ₅ and n ₆ are each 4 to 6; X ⁻ is monovalent Anion Show.) At least one of the R ^{3 to} R ⁵ is an alkyl group, an alkenyl group, an alkoxy group, an alkenyloxy group, an alkylthio group, an alkenylthio group, an alkylcarbonyl group, an alkenylcarbonyl group, an alkylcarbonyloxy group, an alkenylcarbonyloxy group, The resin composition according to claim 1, wherein the resin composition is selected from the group consisting of an alkyloxycarbonyloxy group, an alkenyloxycarbonyloxy group, an alkylsulfonyl group, an alkenylsulfonyl group, an alkylsulfonyloxy group, and an alkenylsulfonyloxy group. At least one of R ^{3 to} R ⁵ is an alkylcarbonyl group, an alkenylcarbonyl group, an alkylcarbonyloxy group, an alkenylcarbonyloxy group, an alkyloxycarbonyloxy group, an alkenylcarbonyloxy group, an alkylsulfonyl group, an alkenylsulfonyl group, an alkyl The resin composition according to claim 1 or 2, selected from the group consisting of a sulfonyloxy group and an alkenylsulfonyloxy group. 4. The resin composition according to claim 1, wherein the compound represented by the general formula (1) has a molar extinction coefficient at 193 nm of 4.0 × 10 ⁻³ [cm ² / mol] or less. .   The resin composition according to any one of claims 1 to 4, wherein the compound has at least one naphthalene ring. 6. The resin composition according to claim 1, wherein either n ₁ or n ₂ is 0 and the other is 1.   The compound that reacts with an acid is at least one selected from the group consisting of a compound having a protecting group that is deprotected by an acid, a compound having a polymerizable group that is polymerized by an acid, and a crosslinking agent having a crosslinking action by an acid. The resin composition according to any one of claims 1 to 6. X ⁻ is selected from the group consisting of an alkyl sulfonate anion, an aryl sulfonate anion, a bisalkylsulfonylamide anion, a trisalkylsulfonylmethide anion, and a compound in which at least one hydrogen atom thereof has been substituted with a fluorine atom. It is an anion, The resin composition as described in any one of Claims 1-7. A coating film forming step of forming a coating film on a substrate using the resin composition according to any one of claims 1 to 8,
A photolithographic step of exposing the coating film in a pattern using an active energy ray;
A pattern forming step of developing the exposed coating film to obtain a photoresist pattern.