WO2008032522A1

WO2008032522A1 - Positive-type resist composition and method for formation of resist pattern

Info

Publication number: WO2008032522A1
Application number: PCT/JP2007/065946
Authority: WO
Inventors: Yohei Kinoshita; Takeshi Iwai; Toshiyuki Ogata
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-09-11
Filing date: 2007-08-16
Publication date: 2008-03-20
Also published as: JP2008065282A; TWI363933B; TW200834242A

Abstract

A positive-type resist composition comprising (A) a resin component whose alkali solubility can be increased by the action of an acid and (B) an acid generator component which can generate an acid upon being exposed to light, wherein the resin component (A) has a constitutional unit (a1) represented by the general formula (I) [wherein R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; R1' represents a hydrogen atom or a lower alkyl group; and n represents an integer ranging from 0 to 3].

Description

Specification

Positive resist composition and resist pattern forming method

Technical field

The present invention relates to a positive resist composition and a resist pattern forming method.

This application (September 2006, November 11, 2006, Japanese Patent Application No. 2006-246131, filed) Claimed priority, the contents of which are incorporated herein by reference.

Background art

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is irradiated with radiation such as light or an electron beam through a mask on which a predetermined pattern is formed. A step of forming a resist pattern having a predetermined shape on the resist film is performed by performing selective exposure and developing. Resist material that changes its characteristics so that the exposed part dissolves in the developer is positive, V does not dissolve the exposed part in the developer, and the resist material that changes in characteristics is negative.

In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, pattern miniaturization has rapidly progressed due to advances in lithography technology!

As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, in the past, ultraviolet rays typified by g-line and i-line were used. Currently, mass production of semiconductor devices using KrF excimer laser and ArF excimer laser has begun. In addition, these excimer lasers have shorter wavelength excimer lasers, electron beams, EUV (

2

Extreme ultraviolet rays) and X-rays are also being examined!

[0003] Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies these requirements, a chemically amplified resist (referred to as a chemically amplified resist composition) containing a base resin whose alkali solubility is changed by the action of an acid and an acid generator that generates an acid upon exposure to light. Is sometimes used). For example, a positive chemically amplified resist contains, as a base resin, a resin whose acid solubility is increased by the action of an acid and an acid generator. When forming a resist pattern, the acid generator is exposed to an acid by exposure. Occurs, the exposure area Lucari soluble.

Up to now, as the base resin for chemically amplified resists, polyhydroxystyrene (PHS), which is highly transparent to KrF excimer laser (248 nm), and resins whose hydroxyl groups are protected with acid-dissociable, dissolution-inhibiting groups (PHS resins) ) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, chemically amplified resists that use PHS resin as the base resin component have drawbacks such as low resolution in a process using light at 193 nm, for example.

Therefore, as a base resin for resists (sometimes called resist compositions) currently used in ArF excimer laser lithography, etc., (meth) acrylic acid esters are excellent because of their excellent transparency at around 193 nm. A resin (acrylic resin) having a structural unit in which a force is also induced in the main chain is mainly used! (See, for example, Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2003-241385

Disclosure of the invention

Problems to be solved by the invention

However, when a resist pattern is formed using a conventional resist composition, roughness may occur on the surface of the resist pattern side wall.

For example, in the case of the roughness of the surface of the side wall of the line pattern, that is, the line edge roughness (LER), the roughness may cause variations in the line width and may adversely affect the formation of a fine semiconductor element.

Therefore, as the demand for higher resolution and the power of the increasingly finer resist patterns increases, LER reduction becomes even more important.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a positive resist composition and a resist pattern forming method capable of forming a resist pattern with reduced LER.

Means for solving the problem

As a result of extensive studies, the present inventors use a resin component having a structural unit containing an acetal type acid dissociable, dissolution inhibiting group containing an isobornyl group as a base resin. As a result, the inventors have found that the above problems can be solved, and have completed the present invention.

That is, the first aspect (aspect) of the present invention is a positive type containing a resin component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) which generates an acid upon exposure. In the resist composition, the resin component (A) is a positive resist composition having a structural unit (a1) represented by the following general formula (I).

[0006] [Chemical 11

-'. <<)

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹ ′ represents a hydrogen atom or a lower alkyl group; n represents an integer of 0 to 3. ]

[0007] The second aspect of the present invention includes a step of forming a resist film on a substrate using the positive resist composition of the first aspect, a step of exposing the resist film, and the resist. A resist pattern forming method including a step of developing a film to form a resist pattern.

In the present specification and claims, the “structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer).

Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.

The “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.

The “lower alkyl group” means an alkyl group having from! To 5 carbon atoms. The “halogenated lower alkyl group” is a group in which part or all of the hydrogen atoms of the lower alkyl group are substituted with halogen atoms, unless otherwise specified.

“Exposure” is a concept including general irradiation of radiation.

The invention's effect

According to the present invention, it is possible to provide a positive resist composition and a resist pattern forming method capable of forming a resist pattern with reduced LER.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] << Positive Resist Composition >>

The positive resist composition of the present invention comprises a resin component (A) whose alkali solubility is increased by the action of an acid (hereinafter referred to as “component (A)”), and an acid generator component (B) that generates an acid upon exposure. (Hereinafter referred to as component (B)).

In such a positive resist composition, the component (A) is insoluble in alkali before exposure. When an acid is generated from the component (B) by exposure, the acid acts on the component (A) and exhibits alkali solubility. Increase. Therefore, in the formation of a resist pattern, when selective exposure is performed on a resist film obtained using the positive resist composition, the exposed portion turns to alkali-soluble while the unexposed portion is alkali-insoluble. Therefore, the resist pattern can be formed by performing the alkali image.

[0011] <(A) component>

In the present invention, the component (A) has the structural unit (al) represented by the general formula (I). In addition, the component (A) preferably further has a structural unit (al,) derived from an acrylate ester force containing a tertiary alkyl ester type acid dissociable, dissolution inhibiting group.

The component (A) preferably further has a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group.

In addition, the component (A) preferably further has a structural unit ( _a3 ) derived from an acrylate ester power containing a polar group-containing aliphatic hydrocarbon group.

[0012] Here, in the present specification and the scope of the patent, "structural unit derived from an acrylate ester" means a structural unit configured by cleavage of an ethylenic double bond of an acrylate ester. To do. “Acrylic acid esters” have a hydrogen atom bonded to the carbon atom at the α-position! /, And a substituent (an atom or group other than a hydrogen atom) bonded to the carbon atom at the α-position. It is a concept including what is. Examples of the substituent include a halogen atom, a lower alkyl group, and a halogenated lower alkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.

Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.

Specific examples of the lower alkyl group as a substituent at the _α- position in the acrylate ester include a methyl group, an ethyl group, a propyl group, an isopropyl group, an η-butyl group, an isobutyl group, a tert-butyl group, Examples include lower straight chain or branched alkyl groups such as pentyl group, isopentyl group, and neopentyl group.

The halogenated lower alkyl group as a substituent at the a-position is a group in which part or all of the hydrogen atoms of the lower alkyl group have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, Examples thereof include a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.

In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group. A hydrogen atom, a fluorine atom or a lower alkyl group is preferred. Or it is more preferably a fluorinated lower alkyl group, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred, and a methylol group is most preferred.

[0013] · Unit (al)

The structural unit (al) is a structural unit represented by the general formula (I). By having the structural unit (al), a resist pattern with reduced LER can be formed.

[0014] In the general formula (I), R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group. In R, a halogen atom, a lower alkyl group or a halogenated lower alkyl group is bonded to the α-position of the acrylate ester! /, Teyo! /, A halogen atom, a lower alkyl group or a halogenated lower alkyl group. Same as the group. Of these, a hydrogen atom or a methyl group is particularly preferred, and a methyl group is most preferred. Yes.

R ¹ ′ represents a hydrogen atom or a lower alkyl group. In R ¹ ′, examples of the lower alkyl group include the same lower alkyl groups as those described above for R, and a methyl group, most preferably a methyl group or an ethyl group, is most preferable.

In the present invention, R ¹ ′ is more preferably a hydrogen atom.

n is an integer of 0 to 3, preferably 0 to 2, more preferably 0 or 1, and most preferably 0.

[0015] Specific examples of the structural unit represented by the general formula (I) are shown below.

[0016] [Chemical 2]

[0017] Among the above, it is more preferable to use at least one selected from chemical formulas (al-2-36) to (al-2-39), and in particular, the chemical formula (al-2-38) The power to use S is most preferable.

[0018] The monomer that derives the structural unit (al) can be synthesized, for example, by reacting a compound represented by the following general formula (1) with a compound represented by the following general formula (2). .

[0019] [Chemical 3]

[Wherein R ¹ and n are the same as R ¹ ′ and n in the general formula (I), and X represents a halogen atom. ]

[0020] [Chemical 4]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkynole group. ]

[0021] In the general formula ^{(1), R 1 ',} n is, R ¹ in the general formula (I)', respectively similar to n.

X represents a halogen atom. Of these, X is preferably a chlorine atom or a bromine atom.

Specific examples of the compound represented by the general formula (1) include, for example, (1, 7, 7 trimethylbicyclo [2.2.1] heptane-2-inole) chloromethyl ether, (1,7,7 trimethylbicyclo Mouth [2.2.1] heptane 2-yl) bromomethyl ether.

In the general formula (2), R represents a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated lower alkyl group. R is the same as R in formula (I). Specific examples of the compound represented by the general formula (2) include acrylic acid, methacrylic acid, or trifluoromethylacrylic acid.

[0022] In the method for producing a monomer for deriving the structural unit (al), the amount of the compound represented by the general formula (2) is usually used relative to the compound represented by the general formula (1). 0.8 to 5 times mol, preferably (1.0 to 2.0 times monole).

The reaction temperature is usually 200 to 200 ° C, preferably -50 to 100 ° C. The reaction pressure is usually 0.01 to absolute pressure;! OMPa, preferably normal pressure to IMPa.

When the reaction pressure is too low, the solubility of the generated hydrogen halide gas in a solvent or the like decreases, and the reaction time becomes longer. If the reaction pressure is too high, special equipment is required, which is not economical.

[0023] In the reaction, a solvent can be used in some cases, for example, hydrocarbon solvents such as hexane, heptane, and octane; aromatic solvents such as benzene, toluene, xylene; diethyl ether, diisopropyl ether, Examples include ether solvents such as tetrahydrofuran; halogen solvents such as dichloromethane, chlorophenol, and carbon tetrachloride; acetone, acetonitrile, N, N-dimethylformamide, dimethyl sulfoxide, and the like.

[0024] The reaction can be performed in the presence of a basic substance, if necessary.

Examples of basic substances include trimethylamine, triethylamine, tributylamine, trioctanolamine, pyridine, lithium carbonate, potassium carbonate, sodium carbonate and the like. The amount of basic substance used is represented by the general formula (2). It is ;! to 5 times mol, preferably;! To 2 times mol for 1 mol of the compound represented.

[0025] After completion of the reaction, the reaction product is usually washed with an aqueous basic compound in order to remove the compound represented by the general formula (2) that has not been reacted.

Here, as the basic compound, an inorganic basic compound is preferable even in the power of using a general basic compound.

Specifically, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium phosphate, sodium hydroxide, water A potassium oxide etc. can be mentioned.

As basic compounds, it is possible to use organic basic compounds such as trimethylamine, triethylamine, tributylamine, trioctylamine, pyridine, etc. Compared to inorganic basic compounds, organic basic compounds are removed by washing with water. Therefore, it remains in the monomer for deriving the structural unit (al), which may affect the storage stability of the compound.

[0026] The reaction product is washed with an aqueous basic compound solution, subjected to a general post-treatment operation, and then the solvent is distilled off under reduced pressure to obtain a monomer that induces the structural unit (al). And force S.

The monomer derived from the structural unit (al) thus obtained should be used as a product. In addition, in consideration of the properties of the monomer that induces the structural unit (al) to be obtained and the type of impurities contained, purification such as distillation and crystallization may be performed.

[0027] The compound represented by the general formula (1) can be produced, for example, by reacting borneol with formaldehyde or paraformaldehyde and hydrogen chloride gas or hydrogen bromide gas in an organic solvent. Monkey.

The reaction temperature is usually 200 to 200 ° C, preferably -50 to 100 ° C.

The reaction pressure is usually 0.01 to absolute pressure;! OMPa, preferably normal pressure to IMPa.

When the reaction pressure is too low, the solubility of hydrogen chloride gas or hydrogen bromide gas used in the reaction in a solvent or the like decreases, and the reaction time becomes longer.

If the reaction pressure is too high, special equipment is required, which is not economical.

[0028] As the organic solvent, an organic solvent having a water solubility of 5 mass% or less in the organic solvent at the reaction temperature is usually used.

Specific examples include hydrocarbon solvents such as hexane and heptane; ether solvents such as jetyl ether and dibutyl ether; halogen solvents such as dichloromethane and carbon tetrachloride.

[0029] After completion of the reaction, water produced by the reaction and the organic layer are separated.

Unreacted formaldehyde or paraformaldehyde moves to the aqueous layer and is removed. By removing the solvent from the obtained reaction product under reduced pressure, the compound represented by the general formula (1) can be obtained.

The obtained compound represented by the general formula (1) may be used in the production of a monomer for deriving the structural unit (al) as it is, or purified by distillation, recrystallization or the like as necessary. Later, it may be used to produce monomers that derive structural units (al)! /.

[0030] In the component (A), as the structural unit (al), one type may be used alone, or two or more types may be used in combination.

The proportion of the structural unit (al) in the component (A) is preferably 10 to 80 mol%, preferably 20 to 70 mol%, based on the total of all the structural units constituting the component (A). More preferably, it is more preferably 25 to 50 mol%. By setting it above the lower limit, The effect of adding al) can be sufficiently obtained, and by making it lower than the upper limit, it is possible to balance with other structural units.

[0031] · Unit (al ')

In the present invention, it is preferable that the component (A) further has a structural unit (al,) derived from an acrylate ester force containing a tertiary alkyl ester type acid dissociable, dissolution inhibiting group.

Here, in the present specification and claims, “tertiary alkyl ester” means that a hydrogen atom of a force-loxy group is substituted with a chain or cyclic alkyl group having a tertiary carbon atom. A structure in which an ester is formed, and the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of the carbonyloxy group (one C (O) —O—). Show.

“Acid dissociation” in an acid dissociable, dissolution inhibiting group means that the component (A) can be dissociated by the action of an acid generated from the component (B) during exposure.

The “dissolution-inhibiting group” is a group that has an alkali dissolution inhibiting property that makes the entire component (A) insoluble in alkali before dissociation, and is a group that changes the entire component (A) to alkali-soluble after dissociation. The “tertiary alkyl ester type” group means that the acid dissociable, dissolution inhibiting group is a tertiary atom bonded to the terminal oxygen atom of the carbonyloxy group (one C (O) —O—). Means containing carbon atoms. In such a structure, when an acid is generated from component (B), the bond between the oxygen atom at the terminal of the carbonyloxy group and the tertiary carbon atom is broken by the action of the acid, and the tertiary is Acid dissociable, dissolution inhibiting groups containing carbon atoms (tertiary alkyl ester type acid dissociable, dissolution inhibiting groups) dissociate.

[0032] A tertiary alkyl ester type acid dissociable, dissolution inhibiting group has been proposed as a tertiary alkyl ester type acid dissociable, dissolution inhibiting group of a base resin for chemically amplified resists! / The cyclic or chain alkyl group that is substituted with the hydrogen atom of the carboxyl group of (meth) acrylic acid to form a tertiary alkyl ester is widely known. Being! / The chain or cyclic alkyl group may have a substituent. “(Meth) acrylic acid” means attaly with a hydrogen atom bonded to the α-position. It means one or both of phosphoric acid and methacrylic acid having a methyl group bonded to the α-position. “(Meth) acrylic acid ester” means both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the a-position! /. More specific examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include aliphatic branched acid dissociable, dissolution inhibiting groups, and acid dissociable, dissolution inhibiting groups containing an aliphatic cyclic group. .

Here, “aliphatic branched” means having a branched structure without aromaticity.

The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (a hydrocarbon group), but is preferably a hydrocarbon group. Further, the “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.

As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferred. Specifically, a tert-butyl group, a tert-amyl group, a tert-heptyl group, etc. Can be mentioned.

In the “acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group”, the aliphatic cyclic group may or may not have a substituent. Examples of the substituent include a lower alkyl group having carbon number !!-5, a fluorine atom, a carbon number substituted with a fluorine atom; a fluorinated lower alkyl group having! -5, an oxygen atom (= o), and the like. .

The basic ring structure excluding the substituent of “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.

Specific examples of the aliphatic cyclic group include, for example, substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group! /, May! /, And! //! Examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specifically, monocycloalkanes such as cyclopentane and cyclohexane, adamantane, norbornane, isoborna , Tricyclodecane, and the like, and one or more hydrogen atoms are removed.

In the structural unit (al ′), the aliphatic cyclic group may be a monocyclic group or a polycyclic group, and is particularly preferably a monocyclic group. The number of carbon atoms of the aliphatic cyclic group is preferably 6 to 20, and more preferably 7 to 15; When the aliphatic cyclic group is a monocyclic group, the number of carbon atoms is preferably 5 to 12 and more preferably 5 to 8.

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group, and specifically, 1-methylcyclohexene. Examples include a xyl group, a 1-ethylcyclohexyl group, a 2-methyl-2-adamantyl group, and a 2-ethyl-2-adamantyl group. Alternatively, in a structural unit represented by the following general formula (al "), an aliphatic cyclic group such as an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (-C (O) -0-) And a group having a branched alkylene group having a tertiary carbon atom bonded thereto.

[0034] [Chemical 5]

[In the formula, R is the same as R in the general formula (I), and R 1 and R ^lb are alkyl groups (both linear and branched, preferably 1 to 5 carbon atoms.) Indicates. ]

[0035] In the present invention, as the structural unit (al '), a structural unit represented by the following general formula (al-0-1) and a structure represented by the following general formula (al-0-2) It is preferable to use one or more selected from the group consisting of units.

[0036] [Chemical 6]

---(a 1… 1 :)

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; X ¹ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group. ] [Chemical 7]

-', (& 1-0-2)

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group; Or an aliphatic cyclic group is shown. ]

[0038] In the general formula (al-0-1), it is bonded to the halogen atom, lower alkyl group or halogenated lower alkyl group of R! /, And bonded to the α-position of the acrylate ester! /, Y! /, The same as a nitrogen atom, a lower alkyl group or a halogenated lower alkyl group.

X ¹ is not particularly limited as long as it is a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, and examples thereof include the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group mentioned above. .

In the general formula (al-0-2), R is the same as R in the general formula (al-0-1).

X ² is the same as X ¹ in the formula (al—0—1).

Y ² is an alkylene group or an aliphatic cyclic group, preferably an alkylene group having 1 to 4 carbon atoms or a divalent aliphatic cyclic group, and the aliphatic cyclic group includes a hydrogen atom. Except for the use of two or more removed groups, the same as described above for “aliphatic cyclic group” is used. The power S can be. Among these, as the aliphatic cyclic group for Y ² , a group represented by general formula (y-1) shown below is particularly preferable.

[0040] [Chemical 8]

[Wherein m represents 0 or 1; ]

[0041] More specifically, as a structural unit represented by the general formula (al— 0— 1), the following formula (al— 1 −

;! ) To (al-1 45).

As a structural unit represented by the general formula (al— 0— 2), more specifically, the following formula (al— 3-

;! ) To (al-3-24).

[0042] [Chemical 9]

]

Cal -1-205

]

Emperor W

[ετ¾] [9W) o]

l76S90 / .00Zdf / X3d 81- S meta 800Z OAV

Cal-3 ~ 2t) (81-3-22) (a1-3-2¾ <31 ~ 3 ~ 245

[0047] The structural unit (al ') is particularly represented by the following general formula (a 1-101) that encompasses the structural units of the formulas (al-1 1) to (al-1 14). A structural unit or a structural unit represented by the following general formula (a 1—1-02) including the structural units of the formulas (al—135) to (al—1-40) is preferable.

[0048] [Chemical 14]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group. ]

[0049] [Chemical 15]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹² represents a lower alkyl group. h represents an integer of 1 to 3. ]

[0050] In the general formula (al-1 01)! /, R! /, Or a hydrogen atom, a halogen atom, a lower alkyl group, which may be bonded to the α-position of the acrylate ester, or The same as the halogenated lower alkyl group. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R above, and is preferably a methyl group or an ethyl group.

In general formula (al-1-02)! /, R !! /, hydrogen atom, halogen atom, lower alkyl group or halogenated which may be bonded to the α-position of the above acrylate ester Same as lower alkyl group. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R described above, and is preferably a methyl group or an ethyl group. Since the effect of reducing LER is improved, the lower alkyl group is most preferably a methyl group. For h, 1 or 2 is preferred, and 2 is most preferred.

[0051] In the component (A), as the structural unit (al '), one type may be used alone, or two or more types may be combined. You may use together.

Among these, as the structural unit (al ′), it is more preferable to use the structural unit represented by the formula (a 1-1-02) because the effect of the present invention is particularly good!

The proportion of (A) the structural unit in the component (al '), relative to the combined total of all structural units constituting the component (A), 10 to 80 Monore ^_0/0 Ca Preferably, 20-70 Monore ^_0/0 Ca and still more preferably 25 to 50 Monore ^_0/0 force S. By setting it to the lower limit value or more, it is possible to easily obtain a pattern when a resist composition is obtained. On the other hand, a balance with other structural units can be achieved by setting the upper limit value or less.

[0052] · Unit ( _a 2)

In the present invention, the component (A) preferably further has a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group! /.

Here, the ratatone-containing cyclic group refers to a cyclic group containing one ring (lataton ring) containing a -o-c (o) structure. The rataton ring is counted as the first ring, and if it is only a rataton ring, it is called a monocyclic group, and if it has another ring structure, it is called a polycyclic group regardless of the structure.

The lathetone-containing cyclic group of the structural unit ( _a2 ) has an affinity for a developer film containing water or improving the adhesion of the resist film to the substrate when the component (A) is used for forming a resist film. It is effective for improving the sex.

As the structural unit (a2), any unit can be used without any particular limitation.

Specifically, examples of the latatatone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-petit-latatotone. In addition, examples of the latathone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a latathone ring.

[0054] More specifically, examples of the structural unit (a2) include structural units represented by the following general formulas (a2— ;!) to (a2-5).

[0055] [Chemical 16]

[Wherein, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is 0. Or an integer of 1, and A is an alkylene group having 1 to 5 carbon atoms or an oxygen atom. ]

[0056] R in the general formulas (a2— ;!) to (a2-5) is the same as R in the general formula (I) in the structural unit (al).

The lower alkyl group for R ′ is the same as the lower alkyl group for R in the general formula (I) in the structural unit (al).

In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.

Specific examples of the alkylene group of A to C having 5 to 5 carbon atoms include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.

Specific examples of the structural units of the general formulas (a2-1) to (a2-5) are shown below.

[0057] [Chemical 17]

[] [0059]

[0058

[OZ ^] [0900]

(οι ^ '}

l 6S90 / Z.00rdf / I3d S meta 800Z OAV

[ΙΖ ^] [Ϊ900]

US meta 800Z OAV

[0062] Among these, it is preferable to use at least one selected from the general formulas (a2— ;!) to (a2-5). The general formulas (a2— ;!) to (a2-3) are preferred. It is more preferable to use at least one selected from Specifically, chemical formulas (a2—1—1), (a2—l—2), (a2—2—1), (a2—2—2), (a2—3—l), (a2—3) — 2), (a2-3-9) and (a2-3-10) It is particularly preferable to use at least one selected from force selection.

[0063] In the component (A), as the structural unit ( _a2 ), one type may be used alone, or two or more types may be used in combination.

The proportion of constituent unit (a2) in component (A) is preferably 5 to 60 mol%, preferably 10 to 50 mol%, based on the total of all constituent units constituting component (A). More preferably, it is more preferably 20 to 50 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

[0064] · Unit (a3)

In the present invention, (A) component, further, the polar group-containing aliphatic hydrocarbon group Atari Le ester force the induced structural unit including _(a 3) is preferably to have a! /,. By having the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group substituted by a hydrogen atom of a hydrogen atom of an alkyl group (that is, a fluorinated alkyl alcohol). preferable.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group (preferably an alkylene group) having a carbon number;! To 10 and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, many resins have been proposed for use in resists for resist compositions for ArF excimer lasers.

Among them, an acrylate ester-containing structure containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom is induced. The unit is more preferred. Examples of the polycyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane or the like. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobonolenane, tricyclodecane or tetracyclododecane. Among these polycyclic groups, two or more hydrogen atoms are removed from adamantane! /, Two or more hydrogen atoms are removed from norbornane, and two or more hydrogen atoms are removed from group, tetracyclododecane. The hydrogen atom is removed! /, And the group is industrially preferred! /.

[0065] As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the hydroxy group of acrylic acid is used. The structural unit derived from tilester is preferred. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following general formula (a3-1) is represented by the following formula (a3-2). And a structural unit represented by the following general formula (a3-3) is preferable.

[0066] [Chemical 22]

(a3-3)

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, j is an integer of 1 to 3, k is an integer of 1 to 3, and t 'is; Is an integer of -3, 1 is an integer of 1-5, and s is an integer of 1-3. ]

[0067] In the general formulas (a3—;!) To (a3-3), the halogen atom, lower alkyl group or halogenated lower alkyl group of R is bonded to the α-position of the above acrylate ester to form V. Y! /, The same as a halogen atom, a lower alkyl group or a halogenated lower alkyl group.

In general formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group. j is a force S of 1 and preferably a hydroxyl group bonded to the 3-position of the adamantyl group.

In general formula (a3-2), k is preferably 1. The Ciano group is bonded to the 5th or 6th position of the norbornyl group!

In general formula (a3-3), t ′ is preferably 1. 1 is preferably 1. s is preferably 1. These have a 2-norbornyl group or 3-norbornyl group bonded to the end of the carboxy group of acrylic acid! The fluorinated alkyl alcohol (hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom) is preferably bonded to the 5th or 6th position of the norbornyl group.

In the component (A), as the structural unit (a3), one type may be used alone, or two or more types may be used in combination. The proportion of (A) the structural unit in the component (a3) is the (A) with respect to the sum of all structural units constituting the component, preferably to be 5 to 50 mole ^_0/0 device 5-40 mole ^_0/0, it is rather more preferable, more preferably 5 to 25 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

[0071] (Other structural units)

In the present invention, the component (A) includes other structural units other than the structural units (a :!) to (a3) and (al ′) as long as the effects of the present invention are not impaired! Moyo! /

Such other structural units are not particularly limited as long as they are not classified into the above structural units (al) to (a3) and (al ′). For ArF excimer lasers and KrF excimer lasers A number of hitherto known materials can be used as resist resins such as (preferably for ArF excimer laser).

Specific examples of other structural units include, for example, acrylic ester-containing structural units (all) containing an acetal type acid dissociable, dissolution inhibiting group, and acrylic acid containing an acid non-dissociable aliphatic polycyclic group. Examples include the structural unit (a4) derived from acid ester power.

[0072] · Structural unit (al l)

In the present invention, the component (A) may contain a structural unit (all) that is derived from an allylic ester force containing an acetal type acid dissociable, dissolution inhibiting group. However, the same structural unit as the structural unit (al) represented by the general formula (I) is excluded.

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal type acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal type acid dissociable, dissolution inhibiting group is bonded. The

Preferred examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (pi-1).

[0073] [Chemical 23]

[Wherein, R ¹ ′ represents a hydrogen atom or a lower alkyl group; n represents an integer of 0 to 3; Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the above formula (pi-1), Ι ^ ′ and η are the same as R ¹ ′ and η in the general formula (I), respectively.

η is preferably an integer from 0 to 2, and 0 or 1 is more preferable, and 0 is most preferable.

Examples of the lower alkyl group for R ¹ ′ include those similar to the lower alkyl group for R above.

Most preferred is a methyl group, preferably a methyl group or an ethyl group.

In the present invention, a group in which R ¹ ′ in the above formula (pi-1) is a hydrogen atom is particularly preferable.

Examples of the lower alkyl group for Y include the same as the lower alkyl group for R above.

Yes

The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups conventionally proposed in a number of ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group. However, an aliphatic polycyclic group (that is, a group in which one hydrogen atom is removed from isobornane) contained in the structural unit represented by the general formula (I) is excluded.

Specific examples of the aliphatic cyclic group for Y include those having the structure represented by the following chemical formula.

[0075] [Chemical 24]

[0076] Further, examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p2).

[0077] [Chemical 25]

…)

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may combine to form a ring! / ! / ]

[0078] In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, and may be a straight chain or branched chain ethyl group or a methyl group is preferred. Most preferred. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.

R ¹⁹ is a linear, branched or cyclic alkyl group, and preferably has 1 to 15 carbon atoms, and may be linear, branched or cyclic.

When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group! /. When R ¹⁹ is cyclic, it is preferably from 4 to 15 carbon atoms, preferably from 4 to 15 carbon atoms, and more preferably 12 from 5 to 10 carbon atoms. Specifically, it is substituted with a fluorine atom or a fluorinated alkyl group! /, May! /, And! /, Not! /, Monocycloalkane, bicycloalkane, tricycloalkane And a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as tetracycloalkane. Specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Is mentioned. Among them, a group in which one or more hydrogen atoms are removed from adamantane is preferable.

In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ The end may be bonded.

In this case, a cyclic group is formed by R ¹⁷ and R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. As the cyclic group, a 4- to 7-membered ring is preferable, and a 4- to 6-membered ring is more preferable. Specific examples of the cyclic group include a tetrahydrobilanyl group and a tetrahydrofurayl group.

[0079] As the structural unit (al l), a tertiary alkyl ester type acid dissociable, dissolution inhibiting group for X ¹ in the general formula (al-0-1) listed in the structural unit (al '), Or consisting of structural units in which the tertiary alkyl ester type acid dissociable, dissolution inhibiting group in X ² of the general formula (al-0-2) is replaced with the above-mentioned acetal type acid dissociable, dissolution inhibiting group, respectively. It is preferable to use at least one selected from the group! /.

Specific examples of the structural unit in which the tertiary alkyl ester type acid dissociable, dissolution inhibiting group in X ¹ of the general formula (al-0-1) is replaced with the acetal type acid dissociable, dissolution inhibiting group include the following. Formulas (al-2— ;!) to (al-2-43) are included.

Specific examples of the structural unit in which the tertiary alkyl ester type acid dissociable, dissolution inhibiting group in X ² of the general formula (al-0-2) is replaced with the acetal type acid dissociable, dissolution inhibiting group include the following. And formulas (al-4— ;!) to (al-4-30).

[0080] [Chemical 26]

[0081] [Chemical 27]

[0082] [Chemical 28] .002r /: I> d

Or ΐ3¾ί ί

[¾] ssso

on ί 3ε27

[W3 SS0O

[ΐε¾] [9800]

l76S90 / .00Zdf / X3d 98 S meta 800Z OAV

ia1 ~ 4 ~ 2fi) (a I -4-27) (a «-4-28} (a -4-293 Cat -4-30)

In the component (A), as the structural unit (all), one type may be used alone, or two or more types may be used in combination.

When such a structural unit (al 1) is contained in the component (A), the proportion of the structural unit (al l) in the component (A) is based on the total of all structural units constituting the component (A); and more preferably from to 50 mol% is preferred tool 10 to 40 mole ^_0/0.

[0087] · Unit ( _a 4) In the present invention, the component (A) includes a structural unit (a4) derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group! /.

Examples of the polycyclic group include those similar to those exemplified in the case of the structural unit (al ′) described above. For ArF excimer laser, KrF excimer laser (preferably ArF As a resin component of a resist composition such as an excimer laser), many conventionally known ones can be used.

In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a substituent, and the substituent which may be omitted may be a linear or branched alkyl group having carbon atoms;! To 5 You may have.

Specifically, as the structural unit (a4), it is possible to display the structures of the following general formulas (a4— ;!) to (a4-5).

[Chemical 32]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group. ]

In the general formulas (a4— ;!) to (a4-5), the halogen atom, lower alkyl group or halogenated lower alkyl group of R is bonded to the α-position of the above acrylate ester. ! /, Teyo The same as V, No, Logen atom, lower alkyl group or halogenated lower alkyl group. When the component (a4) is contained in the component (A), the proportion of the component (a4) in the component (A) is based on the total of all the components constituting the component (A); It is preferably mol%, more preferably 10 to 20 mol%. [0090] In the positive resist composition of the present invention, the component (A) contains at least a resin (polymer) having the structural unit (a1).

In the positive resist composition of the present invention, as the component (A), one type may be used alone, or two or more types may be used in combination.

[0091] The component (A), when used alone, is a resin (polymer) having the structural unit (al), preferably the structural unit (al) and the structural unit. A resin having (a2) and / or the structural unit (a3). Examples of the resin include a copolymer composed of the structural units (a 1) and (a2), a copolymer composed of the structural units (a 1) and (a3), the structural units (al), ( A copolymer comprising a2) and (a3) is mentioned as a preferred one, and the copolymer is represented by the following formula (A1-11) described later because the effects of the present invention are improved. A copolymer containing such a combination of structural units is particularly preferred.

[0092] As the component (A), when two or more kinds are used in combination, the resin (A1) having the structural unit (al) and the resin (A2) having the structural unit (al ') It is preferable to contain. By including the resin (A1) and the resin (A2), it is possible to form a resist pattern with reduced LER. In particular, in forming a finer resist pattern, a resist pattern with reduced LER can be formed.

Hereinafter, the resin (A1) and the resin (A2) will be described.

[0093] [Resin (A1)]

In the present invention, the resin (A1) has the structural unit (al).

The resin (A1) preferably further has the structural unit (a2) in addition to the structural unit (al).

The resin (A1) preferably has the structural unit (a3) in addition to the structural unit (al). Alternatively, the resin (A1) preferably further includes the structural unit (a3) in addition to the structural unit (al) and the structural unit (a2).

In addition, the resin (A1) is a structural unit other than the structural units (al) to (a3) (for example, the structural units (al 1), (a 4), etc.) within a range not impairing the effects of the present invention. ) May be included. [0094] In the resin (Al), the proportion (molar ratio) of each structural unit is improved with respect to the total of all the structural units constituting the resin (A1). it mosquito preferably al) is 10 to 80 Monore ^_0/0, preferably from mosquitoes 20 to 70 Monore ^_0/0, more preferably 25 to 50 molar%.

Based on the combined total of all the structural units that constitute the resin (A1), the structural unit _(a 2) that force is 5 to 60 mol% S preferably 10 to 50 mole ^_0/0, it is more preferable instrument 20 50 mole ^_0/0 Dearuko and more preferably.

Based on the combined total of all the structural units that constitute the resin (A1), construction unit (a3) and more preferably tool 5 that it is 5 to 50 mol% is preferred tool 40 mol ^_0/0 more preferably 25 mol ^_0/0.

Further, when the structural unit (al l) is contained in the resin (A1), the structural unit (al l) is preferably 1 to 50 mol% with respect to the total of all the structural units constituting the resin (A1). Mashigu 10-40 mole ^_0/0 and more preferably is! /,.

Further, when the structural unit (a4) is contained in the resin (A1), the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the resin (A1). It is more preferable to be 10-20 mol%! / ,.

In the present invention, a preferable example of the resin (A1) includes a copolymer having the structural units (al), (a2) and (a3).

As such a copolymer, a copolymer composed of the structural units (al), (a2) and (a3) can be exemplified as a suitable one. Specifically, such a copolymer includes a combination of structural units represented by the following formula (A1-11).

[0096] [Chemical 33]

(A 1-1 1}

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and n is an integer of 0 to 3. ]

[0097] In general formula (A1-11)! /, R! /, Hydrogen atom, halogen atom, lower alkyl group or halogenated which may be bonded to the α-position of the acrylate ester The same as the lower alkyl group, a hydrogen atom or a methyl group is preferred. Of these, it is most preferable that each R is a methyl group! /.

η is preferably an integer from 0 to 2, and 0 or 1 is more preferable. 0 force S is most preferable.

[0098] The mass average molecular weight (Mw) of the resin (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000 < 5,000 to 20000 most preferred. If it is smaller than the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

The dispersity (Mw / Mn) is preferably 1 · 0 to 5 · 0 force S, more preferably 1 · 0 to 3 · 0, and most preferably 1.2 to 2.5. Μη represents the number average molecular weight.

[0099] In the component (ii), as the resin (A1), one type may be used alone, or two or more types may be used in combination.

(Ii) The proportion of the resin (A1) in the component is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and most preferably 20 to 50% by mass. . Being above the lower limit of this range makes it easier to obtain resist patterns with reduced LER. The On the other hand, by being below the upper limit value, the balance with the resin (A2) becomes good, and the lithography characteristics (exposure margin, etc.) are improved.

[0100] [Resin (A2)]

In the present invention, the resin (A2) has the structural unit (al ′).

The resin (A2) preferably further has the structural unit (a2) in addition to the structural unit (al ′).

The resin (A2) preferably has the structural unit (a3) in addition to the structural unit (al ′). Alternatively, the resin (A2) preferably further includes the structural unit (a3) in addition to the structural unit (al ′) and the structural unit (a2).

The resin (A2) is a structural unit other than the structural unit (al ′), (a2), (a3) (for example, the structural unit (al l)) as long as the effects of the present invention are not impaired. (A4) etc.).

[0101] In the resin (A2), the proportion (molar ratio) of each structural unit is improved with respect to the total of all structural units constituting the resin (A2). al ') is that mosquito preferably 10-80 Monore ^_0/0, preferably from mosquitoes 20 to 70 Monore ^_0/0, more preferably 25 to 50 molar%.

Based on the combined total of all the structural units that constitute the resin (A2), it forces S preferably the structural unit (a2) from 5 to 60 mol%, more preferably 10 to 50 mole ^_0/0 device 20 more preferably a Dearuko 50 mol ^_0/0.

Based on the combined total of all the structural units that constitute the resin (A2), construction unit (a3) and more preferably tool 5 that it is 5 to 50 mol% is preferred tool 40 mol ^_0/0 more preferably 25 mol ^_0/0.

Further, when the structural unit (al l) is contained in the resin (A2), the structural unit (al l) is preferably 1 to 50 mol% with respect to the total of all the structural units constituting the resin (A2). Mashigu 10-40 mole ^_0/0 and more preferably is! /,.

Further, when the amount of the structural units _(a 4) to the resin (A2), the combined total of all structural units of which constitute the resin (A2), that the structural unit (a4) from 1 to 30 mol% good It is more preferable to be 10-20 mol%! / ,. [0102] In the present invention, a preferable example of the resin (A2) includes a copolymer having the structural units (al '), (a2) and (a3).

Preferred examples of such a copolymer include the structural units (al ′), (a2) and (a3) powerful copolymers. Specifically, such a copolymer includes a combination of structural units represented by the following formula (A2-11).

[0103] [Chemical 34]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; R ^{1 ()} represents a lower alkyl group. ]

[0104] In general formula (A2-11)! /, R! /, Hydrogen atom, halogen atom, lower alkyl group or halogenated which may be bonded to the α-position of the above acrylate ester The same as the lower alkyl group, a hydrogen atom or a methyl group is preferred. Of these, it is most preferable that each R is a methyl group! /.

The lower alkyl group for R ^{1 () is the same as} the lower alkyl group for R above, and is most preferably a methyl group, preferably a methyl group or an ethyl group.

[0105] The weight average molecular weight (Mw) of the resin (A2) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000 < 5,000 to 20000 most preferred. If it is smaller than the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

The dispersity (Mw / Mn) is preferably 1 · 0 to 5 · 0 force S, more preferably 1 · 0 to 3 · 0, and most preferably 1.2 to 2.5. In the component (A), as the resin (A2), one type may be used alone, or two or more types may be used in combination.

The proportion of the resin (A2) in the component (A) is preferably 10 to 90% by mass, more preferably 20 to 85% by mass, and most preferably 50 to 80% by mass. . By being above the lower limit of this range, the balance with the resin (A1) is good and the lithography properties (exposure margin, etc.) are improved. On the other hand, a resist pattern with a reduced LER is easily obtained when it is not more than the upper limit.

[0107] In the present invention, in the component (A), the mixing ratio (mass ratio) of the resin (A1) and the resin (A2) is not particularly limited. ): Resin (A2) = 90: 10 ~; 10:90 is preferable, 85: 15 ~; 15:85 is particularly preferable, and 50: 50-20: 80 is most preferable. Better!/,. When the ratio of the resin (A1) is at least the lower limit of the above range, a resist pattern with reduced LER is easily obtained. On the other hand, when the ratio of the resin (A1) is not more than the upper limit of the above range, the balance with the resin (A2) becomes good and the lithography properties (exposure margin etc.) are improved.

[0108] The component (A) is an optional component conventionally proposed as a base resin for a chemically amplified resist composition, in addition to the resin (A1) and the resin (A2), as long as the effects of the present invention are not impaired. It may contain a resin component (polymer).

For the effect of the present invention, the total ratio of the resin (A1) and the resin (A2) in the component (A) is preferably 50 to 100% by mass. 70 to 100% by mass It is more preferable to be 100% by mass.

[0109] The component (A) is a monomer derived from each structural unit, such as azobisisobutyronitrile.

It can be obtained by polymerization by known radical polymerization using a radical polymerization initiator such as (AIBN).

In addition, the component (A) includes, for example, HS—CH—CH—CH—C (CF

2 2 2

) C (CF) — OH at the end by using a chain transfer agent such as OH together

3 2 3 2 groups may be introduced. In this way, copolymers introduced with hydroxyalkyl groups in which some of the hydrogen atoms in the alkyl group have been replaced with fluorine atoms reduce development defects and LER (Line Edge Roughness: uneven unevenness on the line sidewalls). ).

In addition, the component (A) is obtained by mixing each polymer obtained by the above method, for example. Obtaining power with S

[0110] The total weight average molecular weight (Mw) of the component (A) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but 2000 to 50000 is preferred <, 3000 to 30000 More preferred <, 5000-20000 most preferred. If it is smaller than the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good. .

Further, the dispersity (Mw / Mn) of the entire component (A) is preferably 1 · 0 to 5 · 0 force S, more preferably 1 · 0 to 3 · 0, and most preferably 1.2 to 2.5.

In the present invention, the total content of component (i) in the positive resist composition may be adjusted according to the resist film thickness to be formed! /.

[0111] <(Β) component>

The component (ii) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt-based acid generators such as odonium salts and sulfonium salts, oxime sulfonate-based acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bi-vinyl). Various compounds are known, such as diazomethane acid generators such as (sulphonyl) diazomethanes, nitrobenzil sulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators.

[0112] As the onium salt-based acid generator, for example, an acid generator represented by the following general formula (b-0) can be preferably used.

[0113] [Chemical 35]

R5t _S o _3-

[Wherein R ^bl represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group; R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, Atom, linear or branched alkyl group, linear or branched alkyl halide group Or a linear or branched alkoxy group; R ^5d is an optionally substituted aryl group; u ″ is an integer of 1 to ₃ .

In the general formula (b-0), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group.

The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. . The cyclic alkyl group preferably has 4 to 12 carbon atoms, preferably 5 to 10 carbon atoms, more preferably 6 to 10 carbon atoms, and most preferably 10 to 10 carbon atoms.

The linear or branched fluorinated alkyl group has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. Most preferred.

The cyclic fluorinated alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms! / ,.

The fluorination rate of the fluorinated alkyl group (ratio of the number of substituted fluorine atoms to the total number of hydrogen atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. In particular, all hydrogen atoms substituted with fluorine atoms are preferred because the strength of the acid increases.

R ⁵¹ is most preferably a linear alkyl group or a linear fluorinated alkyl group.

[0116] R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, a linear or branched alkyl group, a linear or branched alkyl halide group, or a linear or branched alkoxy group. .

In R ⁵² , examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom, and a fluorine atom is preferable.

In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably:! To 5, more preferably 1 to 4, and further preferably 1 to 3.

In R ⁵² , the halogenated alkyl group is a straight or branched chain group in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. Here Examples of the alkyl group include those similar to the “linear or branched alkyl group” in R ⁵² . Examples of the halogen atom to be substituted include the same as those described for the “halogen atom” in R ⁵² above. In the halogenated alkyl group, it is desirable that 50 to 100% of the total number of hydrogen atoms of the alkyl group are substituted with halogen atoms, and it is more preferable that all are substituted.

In R ⁵² , the alkoxy group is linear or branched, and the number of carbon atoms is preferably 1 to 5, more preferably 1 to 4, and further preferably 1 to 3.

Among these, R ⁵² is preferably a hydrogen atom.

[0117] R ⁵³ is an aryl group that may have a substituent, and examples of the structure of the basic ring (matrix ring) excluding the substituent include a naphthyl group, a phenyl group, and an anthracenyl group. From the viewpoint of the effect of the invention and absorption of exposure light such as ArF excimer laser, a phenyl group is desirable.

Examples of the substituent include a hydroxyl group and a lower alkyl group (straight or branched chain, preferably having 1 to 5 carbon atoms, particularly preferably a methyl group).

The aryl group of R ⁵³ has no substituent! /, More preferably! / ,.

u "is an integer of 1 to 3, 2 or 3 is preferred and 3 is particularly desirable.

[0118] Preferred examples of the acid generator represented by formula (b-0) include the following.

[0119] [Chemical 36]

[0120] The acid generator represented by the general formula (b-0) can be used alone or in combination of two or more. wear.

[0121] Further, other onium salt acid generators of the acid generator represented by the general formula (b-0), for example, a compound represented by the following general formula (b-1) or (b-2) Are also preferably used.

[0122] [Chemical 37]

,,, _(b-

[In the formula, ,, to ", R ⁵ " to R ⁶ "each independently represents an aryl group or an alkyl group; R ⁴ " represents a linear, branched or cyclic alkyl group or a linear, branched or Represents a cyclic fluorinated alkyl group; at least one of ¹ "~! ^" Represents an aryl group, and at least one of R ⁵ "to R 6" represents an aryl group. ]

In formula (b— 1), ¹ “˜! ^” Each independently represents an aryl group or an alkyl group. R ~ ³ "represents at least one aryl group. Of ¹ " ~! ^ ³ ", it is preferred that 2 or more are aryl groups. All" ¹ ! ~! ^ "Are aryl groups. Most preferably

Yes

The aryl group of Ri "to" is not particularly limited, for example, an aryl group having 6 to 20 carbon atoms, and in the aryl group, part or all of the hydrogen atoms are alkyl groups, alkoxy groups, It may or may not be substituted with a halogen atom or the like. The aryleno group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at low cost. Specific examples include a phenyl group and a naphthyl group.

Examples of the alkyl group on which the hydrogen atom of the aryl group may be substituted are a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, which are preferably alkyl groups having 1 to 5 carbon atoms. It is most preferred! /

As the alkoxy group in which the hydrogen atom of the aryl group may be substituted, a methoxy group and an ethoxy group are preferable, and an alkoxy group having 1 to 5 carbon atoms is preferable.

The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

R1 as alkyl group "to R ^3", Nag particularly limited for example, the number of carbon atoms;! A ~ 10 linear And a branched or cyclic alkyl group. From the viewpoint of excellent resolution, the number of carbon atoms is preferably 1 to 5. Specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, A decanyl group, etc. can be mentioned, and it is preferable because it is excellent in resolution and can be synthesized at low cost.

Among these, ¹ “˜! ^” Are most preferably each independently a phenyl group or a naphthyl group.

[0124] R ⁴ "represents a linear, branched or cyclic alkyl group or fluorinated alkyl group.

The linear or branched alkyl group is most preferably 1 to 4 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.

The cyclic alkyl group is a cyclic group as represented by R ¹ ″ and has 4 carbon atoms.

It is most preferable that the carbon number is 4 to 10; more preferably, the carbon number is 6 to 10;

The linear or branched fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. Good.

The cyclic fluorinated alkyl group is a cyclic group as shown in the above R ¹ ″, and preferably has 4 to 15 carbon atoms, preferably 4 to 10 carbon atoms. The preferred number of carbons is 6 to 10;

The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. This is because the strength of the acid is increased.

R ⁴ "is most preferably a linear or cyclic alkyl group, or a linear or cyclic fluorinated alkyl group! / ,.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R 5 "to R ⁶ " represents an aryl group. All of R ⁵ "to R ⁶ " are preferably aryl groups.

Examples of R ⁵ "~ R ⁶ " arele groups are the same as those for ¹ "~! ^" Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for Rl ″ to R ³ ″.

Yes

Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.

"The, R ⁴ in the formula (b- 1)" R ⁴ of formula (b-2) in the same groups as those described above for. Specific examples of the onium salt-based acid generator represented by the formula (b-1) or (b-2) include dinate, bis (4-tert-butylphenol) ordonium trifluoromethanesulfonate.

Sulfonate, tri (4-methylphenol) sulfurium trifluoromethanesulfonate

Triphenoleolomethane sulphonate of monopheninoresimethinores norephonium, its heptaph monomethenores norephonium trifnoleolo methanesnorephonate, its heptafluororeprolone sulphonate or its Nonafluorobutane sulfonate, (4 methylphenylenodi) diphenylate or its nonafluorobutanesulfonate, (4-methoxyphenyl) diphenylate or nonafluorobutanesulfonate, tri (4 tertbutynole) phenyl Or its nonafluorobutane sulfonate, diphenyl (1- (4-methoxy) naphthyphonate or its nonafluorobutane sulfonate, di (1 naphthinore) phenyl sulphone or its nonafluorobutane sulfonate, etc. These onion Onion salts in which the anion portion of the salt is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or Kn-octanesulfonate can also be used.

[0127] Further, in the general formula (b-1) or (b-2), an anion salt system in which the anion part is replaced with an anion part represented by the following general formula (b-3) or (b-4) An acid generator can also be used (the cation moiety is the same as (b-1) or (b-2)).

[0128] [Chemical 38]

Voice 0 ₂ 0 ₂ S—Y "

* N X "-(b-3) -f ... (b-4)

^{S (} ¾ ノ os— z "

[In the formula, X "represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Υ" and Ζ "are each independently at least one hydrogen atom is fluorine. The number of carbon atoms substituted with an atom; represents an alkyl group having! -10.

[0129] X "is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 3 carbon atoms. 5 and most preferably 3 carbon atoms.

Υ "and Ζ" are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably It is C1-C7, More preferably, it is C1-C3.

The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of “アルキル” and “Ζ” is preferably as small as possible within the range of the above-mentioned carbon number for reasons such as good solubility in a resist solvent.

In addition, in the alkylene group of X "or the alkyl group of Υ" and Ζ ", the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the higher the energy of 200 nm or less. The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%. Most preferably, it is a perfluoroalkylene group or a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0130] In this specification, the oxime sulfonate acid generator is represented by the following general formula (B-1). A compound having at least one of the groups represented and having a property of generating an acid upon irradiation with radiation. Such oxime sulfonate acid generators are widely used for chemically amplified resist compositions, and can be arbitrarily selected and used.

Yes

[0131] [Chemical 39]

■ '''■ (8-1:

[In the formula (B-1), R ³¹ and R ³² each independently represents an organic group. ]

[0132] The organic group of R ³¹ and R ^{32 is} a group containing a carbon atom, and an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (a fluorine atom, a chlorine atom, etc. ) Etc.).

As the organic group for R ³¹ , a linear, branched or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. The substituent is not particularly limited, and examples thereof include a fluorine atom, a linear, branched or cyclic alkyl group having 6 to 6 carbon atoms. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent. As the alkyl group, carbon number 1 to 20 is preferable 1 to 10; carbon number 10 is more preferable 1 to 8 is more preferable;! To 6 is particularly preferable carbon number 1 to 4 is most preferred. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all the hydrogen atoms are halogen atoms. It means an alkyl group substituted by. Examples of the halogen atom include a fluorine atom, a chlorine atom, an fluorine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group! /.

The aryl group is most preferably 4 to 20 carbon atoms, preferably 4 to 20 carbon atoms; and more preferably 6 to 10 carbon atoms, more preferably 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. A partially halogenated aryl group is a hydrogen atom. Means an aryl group substituted with a halogen atom, and a fully halogenated aryl group means an aryl group in which all of the hydrogen atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.

R ³¹ is particularly preferably an unsubstituted alkyl group having 14 carbon atoms or a fluorinated alkyl group having 14 carbon atoms! /.

As the organic group for R ³² , a linear, branched or cyclic alkyl group, aryl group or cyan group is preferable. Examples of the alkyl group and aryl group for R ³² include the same alkyl groups and aryl groups as those described above for R ³¹ .

R ³² is particularly preferably a cyano group, an alkyl group having 18 carbon atoms having no substituent, or a fluorinated alkyl group having 18 carbon atoms.

[0134] As the oxime sulfonate-based acid generator, more preferred are those represented by the following general formula (

Examples thereof include compounds represented by B-2) or (B-3).

[0135] [Chemical 40]

R3 c N——0——S0 ₂ ——R ³⁵

I

[In the formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

[0136] [Chemical 41]

[In the formula (B-3), R ^3e represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. R ³⁸ is an alkyl group having no substituent or a halogenated alkyl group. p "is 2 or 3.]

[0137] In the general formula (B- 2), alkyl group or halogen having no substituent group R ³³ The alkyl group is preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.

R ³³ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

Yes

The fluorinated alkyl group for R ³³ preferably has 50% or more of the hydrogen atom of the alkyl group, more preferably 70% or more, and even more preferably 90% or more. .

[0138] The Ariru group R ^34, phenyl group, biphenyl (biphenyl) group, Furuoreniru ([pi Uorenyl) group, a naphthyl group, anthracyl (anthracyl) group (anthryl (Anthryl) group), such as Hue Nantoriru group, aromatic A group obtained by removing one hydrogen atom from a ring of a group hydrocarbon, and a heteroaryl group in which a part of the carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom Etc. Of these, a fluorenyl group is preferred.

The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group, halogenated alkyl group, or alkoxy group in the substituent preferably has 1 to 8 carbon atoms;! To 4 forces S, more preferably. Examples of the halogen atom in the halogenated alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated alkyl group is preferably a fluorinated alkyl group.

[0139] The alkyl group or halogenated alkyl group having no substituent of R ³⁵ has carbon number;

A carbon number of 1 to 6 which is preferably 10 is most preferable, and a carbon number of 1 to 6 is more preferable.

R ³⁵ is preferably a partially or completely fluorinated alkyl group (ie, a fluorinated alkyl group), which is preferably a halogenated alkyl group! /.

The fluorinated alkyl group in R ³⁵ preferably has a hydrogen atom of the alkyl group of 50% or more fluorinated, more preferably 70% or more, and still more preferably 90% or more. This is preferable because the strength of the generated acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

[0140] In the general formula (B-3), an alkyl group having no substituent of R ³⁶ or halogen Examples of the alkyl group include those having no substituent of the above ³ ! /, The same as the alkyl group or the halogenated alkyl group.

Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing 1 or 2 hydrogen atoms from the aryl group for R ³⁴ .

Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include those similar to the alkyl group or halogenated alkyl group having no substituent of the above ⁵ .

P ″ is preferably 2.

Specific examples of oxime sulfonate acid generators include α (ρ toluenesulfonyloxyimino) benzylcyanide, α (ρ chlorobenzenesulfonyloxyimino) benzylcyanide, α- (4-12 trobenzenesulfonyloxy). Xyximino) Benzyl cyanide, α (4 12 tallow 2 trifluoromethylbenzenesulfonyloxymino) benzyl cyanide, α (benzenesulfonyloxyimino) -4 clonal benzil cyanide, α- (benzene Sulfonyloxyimino) -2, 4-dichlorodiphenylcyanide, α (benzenesulfonyloxyimino) -2,6-dichlorodiethylcyanide, α (benzenesulfonyloxyimino) -4 Methoxybenzyl cyanide, α (2-chlorobenzyl benzoxyimino) 4-methoxybenzyl cyanide α (Benzenesulfonyloxymino) Chen-2-ylacetonitrile, α (4-dodecylbenzenesulfonyloxymino) benzyl cyanide, α [(ρ Toluenesulfonyloxymino) 4-methoxyphenoxy] acetonitrile, α [(dodecylbenzene) Sulfonyloxyimino) 4-methoxyphenyl] acetonitrile, a (tosyloxyimino) -4 cenylurocyanide, α (methylsulfonyloxyimino) 1-cyclopentenylrucetonitrile, α (methylsulfonyloxy) Mino) 1-cyclohexenylacetonitrile, a (methenylsulfonyloxymino) 1-cycloheptylacetonitrile, α (methylsulfonoxyximino) 1-cyclootatulacetonitrile, α (trifluoromethylsulfone) Honiloximino 1 Shikuropente two Ruasetonitoriru, _alpha (triflate Ruo B methyl scan Honoré Honi Ruo key Consequences mino) Shikuro hexyl § Seto nitrile, alpha (E chill sulfonyl O key Shiimino) over E chill § Seto nitrile, a (propylsulfonyl O key Consequences Mino ) Propropyla Setonitrinore, α (Cyclohexylsulfonyloximino) -cyclopentylacetonitrinore, α (Cyclohexylsulfonyloximino) -cyclohexylacetonitrile, a (Cyclohexylsulfonyloximino) 1-Cyclopente Dirucetonitrile, a (Ethylsulfonyloxyimino) 1-Cyclopentenylrucetonitrile, α- (Isopropylsulfonyloximino) 1-Cyclopentenylrucetonitrile, α- (η-Butylsulfonyloxyimino) 1-Cyclopentene Ruacetonitrile, α (Ethylsulfonyloxymino) 1-Cyclohexenylacetonitrile, α (Isopropylsulfonyloxymino) 1-Cyclohexenylacetonitrile, α- (η-Butylsulfonyloxyimino) 1-Cyclohexe Nylacetonitrile, α (methylsulfonyloxyimino) phenylolecetonitrile, α (methylsulfonyloxyimino) ρ methoxyphenylacetonitrile, a (trifluoromethylsulfonyloxyimino) phenylacetonitrile, _a (trifluoromethylsulfonyloxyimino) p methoxyphenylacetonitrinore, α (ethylsulfonyloxyimino) ρ methoxyphenylacetonitrile, α- (propylsulfonyloxyximino) ρ methylphenylacetonitrile, α (Methylsulfonyloxyimino) ρ bromophenylacetonitrile and the like are also disclosed in JP-A-9 208554 (paragraphs [0012] to [0014] [Chemical 18] to [Chemical 19])! / , Ruoxime sulfonate acid generator, WO 04/074242 65-85 page of Example;! Can be suitably used O oxime sulfonate-based acid generators disclosed in ~ 40).

Moreover, the following can be illustrated as a suitable thing.

[Chemical 42] . 2 ~~ CF3

[0143] Further preferred examples of the oxime sulfonate acid generator include the following four compounds.

[0144] [Chemical 43]

[0145] Among the acid generators, bisalkyl or bisvalino

Specific examples of the tans include bis (isopropylsulfonyl) diazomethane, bis (p-trubis (1,1-dimethinoleethinoresnorehoninore) diazomethane, bibis (2,4 dimethinolefeninoresnorenoninore), and the like. Can be mentioned.

Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552 and JP-A-11-035573 can also be suitably used. Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) disclosed in JP-A-11 322707.

4-Bis (phenylsulfonyldiazomethylsulfonole) butane, 1,6-bi

The power to raise S.

[0146] As the component (B), one type of these acid generators may be used alone, or two or more types may be used in combination.

In the present invention, it is preferable to use, as the component (B), an onium salt having a fluorinated alkyl sulfonate ion as an ion.

The content of the component (B) in the positive resist composition of the present invention is 0.5 to 30 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the component (A). Within the above range Thus, pattern formation is sufficiently performed. Further, it is preferable because a uniform solution can be obtained and storage stability is improved.

<(D) component>

The positive resist composition of the present invention may further comprise any desired resist pattern shape, post exposure stability or the latent image formed by the pattern-wise exposure of tne resist layer, etc. It is preferable to contain a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as a component.

Since a wide variety of components (D) have already been proposed, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines, can be used arbitrarily from known ones. Is preferred. Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.

The “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity. The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have a carbon number S 1-12! /.

As an aliphatic amine, at least one hydrogen atom of ammonia (NH 2) has a carbon number of 1

Three

Examples thereof include amines (alkylamines or alkylalcoholamines) or cyclic amines substituted with 12 or less alkyl groups or hydroxyalkyl groups.

Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; jetylamine, gen-n-propylamine, gen-n-heptylamine, di-alkylamine. Dialkylamines such as n-octylamine, dicyclohexylamine; trimethinolemine, rietinoleamine, 卜 lie npropynoleamine, 卜 lief, chinoleamine, 卜 lie n pentylamine, tolery n hexylamine, tory n heptylamine, toly n otatylamamine , Tri-n nonanolamine, tri-n-decanolamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine, triisopropano Ruamin, di n O click pentanol § Min, alkyl alcohols § Min such tree n Okutanoru Amin Among these, 5 carbon atoms;. 10 Tri-n-octylamine and triisopropanolamine are particularly preferred, with trianolenoquinamine and alkyl alcoholamine being more preferred.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic ammine) or polycyclic (aliphatic polycyclic ammine).

Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. Aliphatic polycyclic amines having 6 to 10 carbon atoms are preferred. Specifically, 1,5-diazabicyclo [4. 3. 0] —5-nonene, 1,8-diazabicyclo [5 4. 0] — 7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane.

These may be used alone or in combination of two or more.

In the present invention, it is particularly preferable to use a trialkylamine or alkylalcoholamine having 5 to 10 carbon atoms as the component (D).

Component (D) is usually used in the range of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

The positive resist composition of the present invention includes, as optional components, organic carboxylic acids and phosphorus oxoacids and the like for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with time, and the like. It is possible to include at least one compound selected from the group consisting of derivatives (hereinafter referred to as component (E)).

As the organic carboxylic acid, for example, acetic acid, malonic acid, citrate, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.

Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferred.

Examples of the derivative of oxo acid of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and a carbon number of 6 ~; 15 aryl groups and the like.

Phosphoric acid derivatives include di-n-butyl phosphate and diphenyl phosphate And phosphoric acid esters.

Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethylolestenole, phosphonic acid diol n-butyl ester, fenenorephosphonic acid, phosphonic acid diphenenoresestenole, and phosphonic acid dibenzyl ester.

Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.

As the component (E), one type may be used alone, or two or more types may be used in combination.

The component (E) is most preferably salicylic acid, which is preferably an organic carboxylic acid. Component (E) is used at a ratio of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

[0149] The positive resist composition of the present invention further contains, if desired, miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving the coating property, Dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be appropriately added and contained.

[0150] In the positive resist composition of the present invention, the materials (the components (A) and (B) and the various optional components as necessary) are referred to as organic solvents (hereinafter referred to as (S) components. Can be dissolved and manufactured.

As the component (S), it is sufficient if each component to be used can be dissolved into a uniform solution. Any one of conventionally known solvents for chemically amplified resists can be used. Two or more kinds can be appropriately selected and used.

For example, latones such as γ-butyrolatatatone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-η-amyl ketone, methyl isoamyl ketone, 2-heptanone; ethylene glycolol, diethylene glycolol, propylene glycol Polyhydric alcohols such as Nole and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; Monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, etc. monoalkyl ethers or monophenyl ethers of compounds having an ester bond Derivatives of polyhydric alcohols such as compounds having an ether bond [this Among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred.] Cyclic ethers such as dioxane; methyl lactate, ethyl lactate (EU, methyl acetate, ethyl acetate) , Butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc .; anisole, ethyl benzyl ether, cresyl methylolate nore, dipheninoreethenore, dibenzinoreethenore, Examples thereof include aromatic organic solvents such as phenol, butenolevenoleethenole, ethinorebenzene, jetinolebenzene, aminolebenzene, isopropylenobenzene, toluene, xylene, cymene and mesitylene.

These organic solvents may be used alone or as a mixed solvent of two or more. Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and lactic acid ethyl (EU, γ-butyrolacton) are preferred.

A mixed solvent in which PGMEA and a polar solvent are mixed is preferable. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Preferably within range! /.

More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. When PGM E is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, more preferably 3: 7 to 7: Three.

In addition, as the component (S), a mixed solvent of at least one selected from the medium strengths of PGMEA and EL and a γ-bubble outlet is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5.

Furthermore, as the component (S), the above-mentioned mixed solvent of PGMEA and PGME and the mixed solvent of _γ -butyrolatatone are also preferable.

The amount of component (S) used is not particularly limited, but it is a concentration that can be applied to a substrate and the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 5 to 15% by mass. [0151] The positive resist composition of the present invention has an effect that a resist pattern with reduced line edge roughness (LER) can be formed. The reason is not clear, but is presumed as follows.

The resin component used in the present invention has a structural unit (al) containing an acetal type acid dissociable, dissolution inhibiting group. Such an acid dissociable, dissolution inhibiting group can be dissociated with a lower activation energy than, for example, a tertiary alkyl ester type acid dissociable, dissolution inhibiting group. For this reason, in the exposed area, the acid dissociable, dissolution inhibiting group of the structural unit (a 1) is dissociated and the difference in alkali solubility (contrast) between the exposed area and the unexposed area increases immediately. It is considered that the roughness at the boundary between the unexposed area and the unexposed area is improved.

The acid dissociable, dissolution inhibiting group of the structural unit (al) contains an isobornyl group. By containing an isobornyl group, the glass transition temperature of the resin component is considered to be lower than before. Therefore, for example, when forming a resist pattern, it is considered that the resist film is easily softened by a treatment such as PEB (post-exposure heating), and fine irregularities on the resist pattern surface are easily reduced.

For the above reasons, it is estimated that the positive resist composition of the present invention can form a resist pattern with reduced LER.

In the present invention, the exposure margin is good (exposure margin is large).

For example, when forming a line-and-space pattern, the line-to-line is completely separated (a space is formed). The minimum exposure amount is “Eclr”, and it is optimal to form a line width: space width = 1: 1. When the exposure amount is “E1: 1”, the width between Eclr and E1: 1 is large when the positive resist composition of the present invention is used.

Therefore, the margin of exposure [Ms (Margin to separate)] obtained by the following formula is large and the exposure margin is good.

Ms = (“El: l” / “Eclr” — 1) X 100

Also, for example, within the range of ± 5% of E1: 1 above, the dimensional change per lmj / cm ² when forming the L / S pattern of the target dimension [nm / (mj cm) absolute size / Small exposure and good exposure margin.

[0153] <Resist pattern formation method> The resist pattern forming method of the present invention includes a step of forming a resist film on a substrate using the positive resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist pattern. It is a method including the process of forming.

The resist pattern forming method of the present invention can be performed, for example, as follows. That is, first, the positive resist composition is applied onto a substrate such as silicon wafer with a spinner or the like, and a pre-beta (post-apply bake (PAB)) is applied at a temperature of 80 to 150 ° C. To; 120 seconds, preferably 60 to 90 seconds, and ArF excimer laser light is selectively exposed through a desired mask pattern using, for example, an ArF exposure apparatus, and then a temperature of 80 to 150 ° C. Under conditions, apply PEB (post-exposure heating) for 40 to 120 seconds, preferably 60 to 90 seconds. This is then developed using an alkaline developer, for example, 0.;! To 10% by weight aqueous tetramethylammonium hydroxide solution. In this way, a resist pattern faithful to the mask pattern can be obtained.

In some cases, a post-beta step may be included after the alkali development, and an organic or inorganic antireflection film may be provided between the substrate and the coating layer of the resist composition.

The wavelength used for exposure is not particularly limited. ArF excimer laser, KrF excimer laser, F excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron)

2

(Child beam), X-rays, soft X-rays and other radiation. The positive resist composition according to the present invention is particularly effective for an ArF excimer laser.

Example

Next, the ability to explain the present invention in more detail by way of examples The present invention is not limited by these examples.

Resins (A) —;! To (A) -3 used in Examples 1-2 and Comparative Examples 1-2 below were synthesized using monomers (1) to (5) shown below.

[0155] [Chemical 44]

[Synthesis of (1, 7, 7-trimethylbicyclo [2.2.1] heptane-2-yl) chloromethyl etherol 1]

In a 500 mL eggplant flask equipped with a stirrer and a nozole for introduction of hydrogen chloride gas, 46.24 g (300 mmol) of Borne-nore (endo, exo mixture), 11.71 g (390 mmol) of norahonole wanoledehydrate and dried Add 200 mL of dichloromethane and keep it at 30 ° C in a water bath. Stir.

Next, hydrogen chloride gas generated by mixing 175.5 g of sodium chloride and 200 mL of concentrated sulfuric acid at normal pressure was blown into the dichloromethane solution through a nozzle for 60 minutes. Further, after stirring for 60 minutes, gas chromatography analysis of the reaction product revealed that borneol disappeared completely, with a selectivity of 99% (1, 7, 7 trimethylbicyclo [2.2.1] heptane 2— It was confirmed that chloromethyl ether 1 was obtained.

The reaction product was transferred to a separatory funnel, the organic layer and the aqueous layer were separated, and the solvent was distilled off from the organic layer by vacuum distillation to obtain a crude reaction product.

Further, the crude reaction product was distilled under reduced pressure to obtain (1, 7, 7 trimethylbicyclo [2.2.1] heptane-2-yl) chloromethyl ether 1 in a yield of 76 · 2% (yield 46 · 36 g, Gas chromatography purity was 97.0% by mass).

[(Synthesis of (1, 7, 7 Trimethylbicyclo [2.2.1] heptane-2-yl) oxymethyl methacrylate 2]

To a 500 mL eggplant flask equipped with a stirrer, thermometer and dropping funnel, 44 · 60 g of (1, 7, 7 trimethylbicyclo [2.2.1] heptane-2-yl) chloromethyl ether 1 obtained above was added. 220 mmol), 59 mg of methoquinone and 200 mL of hexane were added as polymerization inhibitors, and then cooled in an ice bath until the liquid temperature reached 2 ° C.

At this time, the state in the flask became a colorless and transparent solution.

Next, 33.39 g (330 mmol) of triethinoreamine was dropped from the dropping funnel, and 28.41 g (330 mmol) of methacrylic acid was further dropped.

When methacrylic acid was added dropwise, heat generation was observed, so the dropping rate was adjusted so that the liquid temperature was 15 ° C or lower.

At this time, the state of the reaction solution became a cloudy solution.

After completion of the dropwise addition of methacrylic acid, sampling over time, and using gas chromatography, (1, 7, 7 trimethylbicyclo [2.2.1] heptane-2-inole) chloromethyl ether 1 3 hours until disappearance Stirring was performed to confirm the formation of the target product.

Next, lOOmL of ice water was added to the reaction product and stirred for 3 minutes. The cloudy reaction product became a colorless and transparent solution. This solution was transferred to a separatory funnel, the aqueous layer was separated, and washed 3 times with 100 mL of saturated aqueous sodium hydrogen carbonate solution.

Furthermore, after washing with 200 mL of saturated aqueous sodium chloride solution, it was dried over magnesium sulfate. After filtration of magnesium sulfate, 6 mg of methoquinone was added as a polymerization inhibitor, and the solvent was distilled off under reduced pressure to obtain (1, 7, 7 trimethylbicyclo [2 · 2.1] heptane-2-yl) oxymethyl methacrylate. Talylate 2 was obtained in a yield of 97.7% (yield: 54.2 g, gas chromatography purity: 96.8%).

[0160] (spectral data)

• Nuclear magnetic resonance spectrum (Solvent: Kuroguchi Form d) [JEOL Ltd. $ ϋΝΜ ECA 500]

— NMR (500MHz): 0.78— 1.25 (m, 13H), 1.92 (s, 3H), 1.50— 2.2 5 (m, 3Η), 3.50-4.85 (m, 1H), 5.25— 5.45 (m, 2H), 5.59 (s, 1H), 6.13 (s, 1H)

¹³ C-NMR (126 MHz): 11.86, 13.55, 18.29, 18.89, 19.71, 20.15, 2 0.20, 26.54, 27.20, 28.19, 34.36, 36.85, 39.48, 45.06, 45.18, 46.71, 47.64, 49.15, 49.43, 86.29 , 88.55, 90.09, 90.18, 125.98, 12 6.03, 136.39, 166.92

• GC-MS (EI) (Shimadzu Corporation GCMS—QP2010)

252 (Μ +, 0.1%), 166 (22.2%), 137 (32.6%), 121 (30.4%), 109 (43

1%), 95 (100%), 81 (38.5%), 69 (98.6%), 55 (15.6%), 41 (51.7%) [0161] Resin (Α) — Taking 1 as an example, nitrogen PGMEA was placed in a flask equipped with an inlet, a stirrer, a condenser and a thermometer under a nitrogen atmosphere, and the temperature of the hot water bath was raised to 80 ° C while stirring.

Next, 2, 2'-azobisisobutyronitrile (AIBN), PGMEA and

, Monomer (1) / monomer (4) / monomer (5) = 4/4/2 (molar ratio) mixed in a flask over 6 hours at a constant rate using a dropping device. Then dripping into

And kept at 80 ° C for 1 hour. Thereafter, the reaction solution was returned to room temperature.

Next, the obtained reaction solution is dropped into about 30 times amount of methanol with stirring, and A colored precipitate was obtained. The resulting precipitate was filtered off and washed in about 30 times the amount of methanol used for the polymerization. The precipitate was filtered off and dried at 50 ° C. under reduced pressure for about 40 hours to obtain Resin (A) -1.

Resins (A) -2 and (A) 3 were synthesized in the same manner as in the above resin (A) -1, except that the monomer for deriving the structural unit of each polymer was used in a predetermined molar ratio. A) —Synthesized by the same method as in 1.

[0162] The obtained resins (A) — ;! to (A) -3 are shown below.

In the resins (A) —;! To (A) -3, the mass average molecular weight (Mw) and the dispersity (M w / Mn) were determined on the basis of polystyrene conversion by gel permeation chromatography (GPC), respectively. It was.

In addition, the thermal decomposition temperature (Td) and glass transition temperature (Tg) of the resins (A) — ;! to (A) -3 were measured. Td (° C) was measured with a thermal analyzer DSC6200 (product name, manufactured by Seiko Instrument Co.) under a temperature rising condition of 10 ° C / min. Tg (° C) was measured with a thermal analyzer TG / D TA6200 (product name, manufactured by Seiko Instrument) under a temperature rising condition of 10 ° C / min.

Further, the composition ratio indicating the proportion (mol%) of each structural unit in the resins (A) — ;! to (A) -3 was calculated by carbon NMR (nuclear magnetic resonance spectrum). Resin (A) — ;! to (A) -3 The following chemical formula showing the structure of (A) — ;! to (A) -3, the numbers attached to the lower right of each structural unit are in the resin The ratio (mol%) of each structural unit is shown.

[0163] [Chem 46]

(Mw = 6700, Mw / Mn = 2. 17, Td / Tg = 255/137)

[0164] [Chemical 47]

(A) -2

(Mw = 7000, Mw / Mn = 2. 16, Td / T = 237/188)

[0165] [Chemical 48]

(Mw = 10000, Mw / Mn = l .7)

[0166] (Examples;! To 2, Comparative examples;! To 2)

Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

[0167] [Table 1]

[0168] Each abbreviation in Table 1 has the following meaning. The number in [] is the compounding amount (parts by mass) is there.

[0169] (B) -l: An acid generator represented by the following chemical formula (B) -1.

[0170] [Chemical 49]

[0171] (B) -2: (4 Methylphenolinole) diphenylsulfonium nonafluorobutanesulfonate.

(D) —1: Triisopropanolamine.

(D) —2: Tri-n-octylamine.

(E) — 1: Salicylic acid.

(S)-l: γ—petite rataton.

(S) — 2: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).

[0172] A line-and-space resist pattern was formed using the obtained positive resist composition, and the following line edge roughness (LER) and exposure margin were evaluated.

[0173] <Resist pattern formation 1>

A commercially available organic antireflective coating composition was applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 185 ° C for 60 seconds to dry.

A 38 nm organic antireflection film was formed.

On the organic antireflection film, the positive resist compositions of Example 1 and Comparative Example 1 were respectively applied using a spinner, and pre-beta for 60 seconds at a PAB temperature shown in Table 2 on a hot plate. (PAB) was performed and dried to form a 130 nm thick resist film.

Next, an ArF excimer laser (193 nm) was applied to the mask pattern (6% halftone) using an ArF exposure system NSR-S302A (Nikon; NA (numerical aperture) = 0 · 60, 2/3 annular illumination). Irradiation) through a mask.

Then, PEB (post-exposure heating) treatment was performed for 60 seconds at the PEB temperature shown in Table 2, and then paddled for 30 seconds with an aqueous solution of 2.38 mass% tetramethylammonium hydroxide (TMAH) at 23 ° C. The film was developed, rinsed with pure water for 20 seconds, and then shaken and dried. Thereafter, the film was dried by heating at 100 ° C. for 60 seconds to form a line-and-space resist pattern (hereinafter referred to as L / S pattern) having a line width of 120 nm.

[0174] [Evaluation of sensitivity]

L / S pattern force at 120 nm Line width: space width = 1: The exposure amount (sensitivity) (unit: mj / cm ² ) when formed at 1: 1 was determined as “E1: 1”. The results are shown in Table 2. For the 120 nm L / S pattern (1: 1) obtained in E1: 1 above, 3 σ, a measure indicating LER, was determined.

Here, “3σ” means that the width of each resist pattern formed by the positive resist composition is measured by a side length SEM (manufactured by Hitachi, Ltd., product name: S-9220, measurement voltage 300 V). The three times the standard deviation (σ) calculated from the result (3σ) is shown.

This 3σ means that the smaller the value, the more uniform the resist pattern with the smaller roughness of the line sidewall. The results are shown in Table 2.

[0176] [Table 2]

As is clear from the results in Table 2, Example 1 according to the present invention has a smaller LER value than Comparative Example 1, and thus it is confirmed that a resist pattern with reduced LER can be formed. did it.

[0178] [Evaluation of exposure margin]

Gradually increase the exposure amount. When forming a 120 nm L / S pattern in the same manner as in [Resist pattern formation] above, set the minimum exposure amount that separates lines from each other. Sought as Eclrj.

Then, Ms (Margin to separate) was calculated by the following formula as a value for evaluating the exposure margin.

Ms = (“El: l” / “Eclr” — 1) X 100

In addition, in the range of El 5 of ± 5%, the dimensional change per lmj / cm [nm / (mj / cm saw] was prolonged when forming an L / S pattern of 85 nm.

Here, the exposure margin is better as the value of “Ms” is larger, and it is better as the absolute value of “dimensional change” is smaller.

Table 3 shows the values of Eclr, El: 1, Ms, and dimensional change.

[Table 3]

[0180] From the results in Table 3, Example 1 according to the present invention has a higher exposure margin because the Ms value is larger than that of Comparative Example 1 and the absolute value of the dimensional change is small. It was confirmed.

[0181] <Resist pattern formation 2>

A commercially available organic antireflective coating composition is applied onto an 8-inch silicon wafer using a spinner, baked on a hot plate at 185 ° C for 60 seconds, and dried to give an organic reflective film having a thickness of 38 nm. A prevention film was formed.

On the organic antireflection film, the positive resist compositions of Example 2 and Comparative Example 2 were respectively applied using a spinner, and were pre-beta for 60 seconds at a PAB temperature shown in Table 4 on a hot plate. (PAB) was performed and dried to form a 130 nm thick resist film.

Next, an ArF excimer laser (193 nm) was applied to the mask pattern (6% half-tone) using an ArF exposure system NSR-S306C (Nikon; NA (numerical aperture) = 0 · 78, 2/3 annular illumination).

Then, PEB (post-exposure heating) treatment was performed for 60 seconds at the PEB temperatures shown in Table 4, and 2 Paddle development was performed for 30 seconds with a 2.38 mass% tetramethylammonium hydroxide (ΤΜΑΗ) aqueous solution at 3 ° C, followed by water rinsing with pure water for 20 seconds, followed by spin-drying. After that, it was heated and dried at 100 ° C. for 60 seconds to form line and space resist patterns (hereinafter referred to as L / S patterns) having a line width of 80 nm and 85 nm, respectively.

[0182] [Evaluation of sensitivity]

L / S pattern force at 80nm and 85nm Line width: Space width = 1: 1 Exposure amount (sensitivity) (unit: mj / cm ² ) was determined as “E1: 1”. The results are shown in Table 4. For each of the 80/85 nm L / S patterns (1: 1) obtained in E1: 1 above, 3 σ, which is a measure of L ER, is assigned to the side length SEM (manufactured by Hitachi, Ltd., product name: S-9360). The measurement voltage was 300 V) and was obtained by the same method as above. The results are shown in Table 4.

[0184] [Table 4]

[0185] As is apparent from the results in Table 4, Example 2 according to the present invention has an L / S pattern (1: 1) of 80 nm and 85 nm. Compared with, the LER value is small! /, Confirming that a resist pattern with reduced LER can be formed.

Industrial applicability

[0186] Since the present invention can provide a positive resist composition and a resist pattern forming method capable of forming a resist pattern with reduced LER, it is extremely useful industrially.

Claims

A positive resist composition comprising a resin component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) that generates an acid upon exposure, wherein the resin component (A) is a positive resist composition having a structural unit (al) represented by the following general formula (I).

[Chemical 1]

[2] The resin component (A) is a structural unit derived from a resin (A1) having the structural unit (al) and an acrylate ester containing a tertiary alkynolester type acid dissociable, dissolution inhibiting group. The positive resist composition according to claim 1, comprising a resin (A2) having (al ′).

[3] The positive resist according to claim 2, wherein the resin (A1) and / or the resin (A2) further includes a structural unit (a2) derived from an acrylate ester force containing a latathone-containing cyclic group. Composition.

[4] The resin according to [2], wherein the resin (A1) and / or the resin (A2) further has a structural unit (a3) derived from an acrylate ester force containing a polar group-containing aliphatic hydrocarbon group. Positive resist composition.

[5] The resin (A1) and / or the resin (A2) further has a structural unit (a3) derived from an acrylate ester force containing a polar group-containing aliphatic hydrocarbon group. The positive resist composition described above.

6. The positive resist composition according to claim 1, wherein the resin component (A) further has a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group.

7. The positive resist composition according to claim 1, wherein the resin component (A) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.

8. The positive resist composition according to claim 6, wherein the resin component (A) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.

9. The positive resist composition according to claim 1, further comprising a nitrogen-containing organic compound (D).

[10] Using the positive resist composition according to any one of claims 1 to 9, forming a resist film on a substrate, exposing the resist film, and developing the resist film And a resist pattern forming method including a step of forming a resist pattern.