KR102063522B1 - Radiation-sensitive resin composition for liquid immersion exposure and resist pattern forming method - Google Patents

Abstract

This invention is the radiation sensitive resin composition for liquid immersion exposure containing the polymer which has a structural unit represented by [A] following General formula (1), and [B] a radiation sensitive acid generator. In formula (1), R ¹ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ² is a single bond, a divalent linear hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination of one or two or more of them with -O-. R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ^A is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

Description

Radiation-sensitive resin composition for resist immersion exposure and resist pattern formation method {RADIATION-SENSITIVE RESIN COMPOSITION FOR LIQUID IMMERSION EXPOSURE AND RESIST PATTERN FORMING METHOD}

The present invention relates to a radiation-sensitive resin composition for immersion exposure and a method of forming a resist pattern.

The radiation-sensitive resin composition used for microfabrication in the manufacture of integrated circuit devices, for example, generates an acid in an exposed portion by irradiation with ArF excimer laser light or the like, and the reaction is performed by reaction using the acid as a catalyst. A resist pattern is formed by generating a difference in solubility in an alkaline developer between the miner and the unexposed part.

In recent years, the use of the liquid immersion exposure method is expanding as a method of forming a finer resist pattern with a line width of about 45 nm. In the immersion lithography method, even when the numerical aperture NA of the lens is increased, the depth of focus hardly decreases, and there is an advantage that high resolution is obtained. The radiation-sensitive resin composition used in the liquid immersion lithography method prevents deterioration of coating film performance and contamination of lenses and the like by preventing elution of an acid generator or the like from the resist film to the liquid for immersion lithography. It is desired to prevent the remaining watermark and to enable high-speed scan exposure by improving water drainage.

As a means of achieving them, a technique for forming an upper layer film (protective film) on a resist film (see Japanese Patent Laid-Open No. 2005-352384) has been proposed, but this technique requires a film forming process separately and is complicated. On the other hand, the technique of improving the hydrophobicity of the resist film surface is examined, and the radiation sensitive resin composition containing the high hydrophobic fluorine atom containing polymer is known (refer international publication 2007/116664).

On the other hand, if the hydrophobicity of the surface of the resist film is increased in this way, the surface wettability of the developer or rinse liquid is lowered, so that the removal by the development of the exposed portion of the resist film or the rinse of the developing residue deposited on the unexposed portion tends to be insufficient. As a result, there exists a problem that developing defects, such as bridge defects in which a part of patterns are connected in a resist pattern, and blob defects by adhesion of a developing residue generate | occur | produce. In order to suppress such a development defect, the technique using the polymer derived from the trifluoromethyl alcohol group containing alkylester of (meth) acrylic acid is proposed (refer Unexamined-Japanese-Patent No. 2010-176037). According to this technique, the contact angle with respect to a liquid such as water on the surface of the resist film can be made high during immersion exposure and low after development, and as a result, high-speed scan exposure and reduction of development defects can be made in parallel.

However, in the said conventional radiation sensitive resin composition, it was not possible to fully suppress generation | occurrence | production of a development defect, whether the fall degree of the receding contact angle after image development is still inadequate. On the other hand, it is also required to further increase the receding contact angle at the time of immersion exposure to speed up the scanning exposure, thereby improving the productivity of the immersion exposure process.

Japanese Patent Laid-Open No. 2005-352384 International Publication No. 2007/116664 Japanese Patent Publication No. 2010-176037

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above circumstances, and its object is to make the receding contact angle of the resist film surface larger during immersion exposure and smaller after development, and for immersion exposure, which can suppress the occurrence of development defects. It is providing the radiation sensitive resin composition.

The invention made to solve the above problems,

[A] a polymer having a structural unit (hereinafter also referred to as "structural unit (I)") represented by the following general formula (1) (hereinafter also referred to as "[A] polymer"), and

[B] radiation-sensitive acid generators (hereinafter also referred to as "[B] acid generators))

It is a radiation sensitive resin composition for liquid immersion exposure containing the following.

(In formula (1), R <^1> is a hydrogen atom or a C1-C20 monovalent organic group, R <^2> is a single bond, a C1-C20 bivalent linear hydrocarbon group, a C3-C20 bivalent alicyclic type It is a hydrocarbon group or the group which combined 1 or 2 or more types of these, and -O-, R <^3> is a hydrogen atom or a C1-C20 monovalent organic group, R ^<A> is a hydrogen atom or C1-C20 Monovalent organic group)

Since the radiation sensitive resin composition for immersion exposure of the present invention contains the [A] polymer and the [B] acid generator, the receding contact angle of the resist film can be made larger at the time of immersion exposure and smaller after development. It can suppress occurrence. The reason why the above-mentioned radiation-sensitive resin composition for immersion exposure exhibits the above effects by having the above configuration is not necessarily clear, but can be estimated as follows, for example. In other words, the group represented by -C (R ¹ ) (OR ^A ) (CF ₃ ) possessed by the [A] polymer (hereinafter also referred to as “group (a)”) has a fluorine atom and is high in the [A] polymer. Contribute to hydrophobicity On the other hand, a part of the structure of the polymer [A] is hydrolyzed by the action of the alkaline developer, thereby increasing the hydrophilicity. In particular, when R ^A is a hydrogen atom or a base dissociable group, since the OH group in alkali development has high acidity due to electron withdrawing properties of the trifluoromethyl group bonded to the α-carbon of this group, [A] The polymer exhibits high alkali solubility. In addition, in the structural unit (I), this group (a) exists at the said specific position different from -COOR <^3> group. Due to this specific molecular structure, it is believed that the hydrophobicity, hydrophilicity and alkali solubility are effectively exerted, and as a result, the receding contact angle of the surface of the resist film formed of the radiation-sensitive resin composition for immersion exposure can be higher than that in the prior art during immersion exposure. After development, it can greatly reduce. In addition, after the development, the receding contact angle becomes smaller, whereby the developer and the rinse solution can be brought into better contact with the surface of the resist film, and as a result, the occurrence of development defects is effectively suppressed.

The radiation-sensitive resin composition for immersion exposure,

[C] A polymer having a lower fluorine atom content than the polymer [A] (hereinafter also referred to as "[C] polymer")

Further contains,

It is preferable that this [C] polymer has an acid dissociable group.

The radiation sensitive resin composition for liquid immersion exposure usually contains the polymer [C] as a base polymer, in addition to the polymer [A] and the acid generator [B]. By making the fluorine atom content of the polymer [A] higher than the polymer [C], the polymer [A] can be effectively localized to the resist film surface layer, and as a result, the change in the receding contact angle of the resist film surface can be increased. Therefore, according to the said radiation sensitive resin composition for immersion exposure, the receding contact angle of a resist film can be made larger at the time of immersion exposure, can be made smaller after image development, and generation | occurrence | production of a development defect can be suppressed more.

It is preferable that the polymer (A) further has a structural unit (hereinafter also referred to as "structural unit (II)") containing an acid dissociable group. When the polymer (A) further has the structural unit (II), the dissolution residue in the developer of the polymer [A] in the exposed portion can be further suppressed. As a result, the radiation sensitive resin composition for liquid immersion exposure can further suppress the occurrence of development defects.

It is preferable that the said radiation sensitive resin composition for immersion exposure further contains the [D] acid diffusion control body. The radiation-sensitive resin composition for liquid immersion exposure further improves lithographic performance such as resolution while maintaining the properties such as the receding contact angle described above by further containing the [D] acid diffusion controller.

The radiation sensitive resin composition of the present invention,

[A] a polymer having a structural unit represented by the following formula (1),

[B] a radiation sensitive acid generator, and

[C] A polymer having a lower content of fluorine atoms than a polymer [A]

Containing,

This [C] polymer has an acid dissociable group.

(In formula (1), R <^1> is a hydrogen atom or a C1-C20 monovalent organic group, R <^2> is a single bond, a C1-C20 bivalent linear hydrocarbon group, a C3-C20 bivalent alicyclic type It is a hydrocarbon group or the group which combined 1 or 2 or more types of these, and -O-, R <^3> is a hydrogen atom or a C1-C20 monovalent organic group, R ^<A> is a hydrogen atom or C1-C20 Monovalent organic group)

According to the said radiation sensitive resin composition, the receding contact angle of the resist film surface can be made larger, it can be made smaller after image development, and generation | occurrence | production of a development defect can be suppressed.

The resist pattern forming method of the present invention,

Forming a resist film from the radiation-sensitive resin composition for immersion exposure;

Immersing the resist film through a liquid for liquid immersion exposure, and

Developing the immersion-exposed resist film

Has

According to the said resist pattern formation method, since the above-mentioned radiation sensitive resin composition for immersion exposure is used, the resist pattern with few developing defects can be formed, while speeding up scanning exposure.

"Organic" means here the group containing at least 1 carbon atom.

As described above, according to the liquid-sensitive exposure-sensitive radiation-sensitive resin composition and the resist pattern forming method of the present invention, a resist pattern with few development defects can be formed while increasing the speed of scan exposure. Therefore, this invention can be used suitably for a liquid immersion exposure process, and can improve the productivity and the quality of the resist pattern formed.

<Radiation Resin Composition for Immersion Exposure>

The radiation sensitive resin composition for immersion exposure contains the [A] polymer and the [B] acid generator. The radiation sensitive resin composition for immersion exposure may contain, as a suitable component, a [C] polymer, a [D] acid diffusion controller and an [E] solvent, and other optional components within a range that does not impair the effects of the present invention. It may contain. Hereinafter, each component is demonstrated.

<[A] polymer>

The polymer [A] is a polymer having a structural unit (I). The polymer [A] functions as a surface hydrophobic polymer. A "surface hydrophobization polymer" means the polymer of the subcomponent which has a tendency to be localized in the surface layer of the resist film formed by containing in the radiation sensitive resin composition for immersion exposure. Such a polymer [A] can be localized in the surface layer thereof when forming a resist film to hydrophobize the surface of the resist film. As a result, high-speed scan etc. in liquid immersion exposure can be enabled.

From the viewpoint of enhancing the function as the surface hydrophobic polymer, the fluorine atom content of the polymer [A] is preferably higher than the fluorine atom content of the base polymer. As a base polymer, the [C] polymer mentioned later, etc. are mentioned, for example. As a fluorine atom content rate of a polymer (A), 5 mass% or more is preferable, 7 mass% or more is more preferable, and 10 mass% or more is more preferable. The fluorine atom content rate (mass%) of a polymer can be computed from the structure obtained by analyzing the structure of a polymer by ¹³ C-NMR.

[A] The polymer preferably has a structural unit (II) containing an acid dissociable group in addition to the structural unit (I), and may have a structural unit (III) containing a fluorine atom, and the structural unit (I) It may have other structural units other than (III). The polymer (A) may have one, two or more of these structural units. Hereinafter, each structural unit is demonstrated.

[Structural Unit (I)]

Structural unit (I) is a structural unit represented by the said General formula (1). [A] The radiation sensitive for liquid immersion exposure by having the structural unit (I) and having a group (a) represented by -C (R ¹ ) (OR ^A ) (CF ₃ ) separately from the -COOR ³ group The resin composition can make the receding contact angle of the resist film larger during immersion exposure and smaller after development, and can suppress the occurrence of development defects.

Although the reason why the said radiation sensitive resin composition for liquid immersion exposure exhibits the said effect by having a structural unit (I) is not necessarily clear, For example, it can estimate as follows. That is, the group (a) represented by -C (R ¹ ) (OR ^A ) (CF ₃ ) possessed by the [A] polymer has a fluorine atom and contributes to high hydrophobicity of the [A] polymer. On the other hand, a part of the structure of the polymer [A] is hydrolyzed by the action of the alkaline developer, thereby increasing the hydrophilicity. In particular, when R ^A is a hydrogen atom or a base dissociable group, since the OH group in alkali development has high acidity due to electron withdrawing properties of the trifluoromethyl group bonded to the α-carbon of this group, the polymer [A] Indicates high alkali solubility. In addition, in the structural unit (I), this group (a) exists in the said specific position different from -COOR <^3> group. It is believed that the hydrophobicity, hydrophilicity and alkali solubility are effectively exerted due to this specific molecular structure. As a result, the receding contact angle on the surface of the resist film formed of the radiation-sensitive resin composition for immersion exposure can be higher than that during the conventional immersion exposure. After development, it can fall large. In addition, since the receding contact angle becomes smaller after development, the contact between the developer, the rinse solution, and the resist film becomes more effective, so that the occurrence of development defects is suppressed.

In said Formula (1), R <^1> is a hydrogen atom or a C1-C20 monovalent organic group. R ² is a single bond, a divalent linear hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination of one or two or more of them with -O-. R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ^A is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ and R ³ include a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, or one or two or more thereof and -O- The group which combined the coupling group containing hetero atoms, such as -CO-, -OCO-, -COO-, -S-, etc. are mentioned. Some or all of the hydrogen atoms of these groups may be substituted with a fluorine atom, a hydroxy group, a carboxy group, an amino group, a cyano group, or the like.

As said monovalent chain hydrocarbon group, it is, for example

Alkyl groups, such as a methyl group, an ethyl group, a propyl group, and a butyl group;

Alkenyl groups such as ethenyl, propenyl and butenyl;

Alkynyl groups, such as an ethynyl group, a propynyl group, butynyl group, etc. are mentioned.

As said monovalent alicyclic hydrocarbon group, it is, for example

Cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornyl group and adamantyl group;

Cycloalkenyl groups, such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, and a norbornenyl group, etc. are mentioned.

As said monovalent aromatic hydrocarbon group, for example,

Aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group and anthryl group;

Aralkyl groups, such as a benzyl group, a phenethyl group, a naphthyl methyl group, an anthryl methyl group, etc. are mentioned.

R ^{1 is a} hydrogen atom, a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent fluorinated chain hydrocarbon group, a monovalent fluorinated alicyclic type, from the viewpoint of improving the receding contact angle during liquid immersion exposure on the surface of the resist film formed. A hydrocarbon group is preferable, a hydrogen atom and a monovalent perfluoroalkyl group are more preferable, a hydrogen atom and a trifluoromethyl group are more preferable, and a trifluoromethyl group is especially preferable.

R ^{3 is a} hydrogen atom, a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent fluorinated chain hydrocarbon group, or a monovalent fluorinated alicyclic type, from the viewpoint of improving the receding contact angle during liquid immersion exposure on the surface of the resist film formed. A hydrocarbon group is preferable, a methyl group, an ethyl group, a cyclohexyl group, and a hexafluoro-2-propyl group are more preferable, and a hexafluoro-2-propyl group is more preferable.

Examples of the divalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^2, for example, methane diyl, ethane diyl, propane-diyl, butane-diyl, pentane-diyl, hexane-diyl, octane-diyl group, decane-di A diary, a dodecanediyl group, a tetradecanediyl group, a hexadecanediyl group, an octadecanediyl group, an icosandiyl group, etc. are mentioned.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ² include a cyclopropanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, a cyclohexanediyl group, a cyclooctanediyl group and a cyclodecanediyl group. Can be.

As a group which combined -O- with 1 type (s) or 2 or more types of the said linear hydrocarbon group and alicyclic hydrocarbon group represented by R <^2> , For example, methanediyloxy group, an ethanediyloxy group, a propanediyloxy group, butane Alkanediyloxy groups, such as a diyloxy group, a pentanediyloxy group, a hexanediyloxy group, an octanediyloxy group; One -O- such as methanediyloxymethanediyl group, methanediyloxyethanediyl group, methanediyloxy (1,2-propanediyl) group, methanediyloxybutanediyl group, methanediyloxycyclohexanediyl group Containing group; And groups containing two or more —O—, such as propanediyloxyethanediyloxyethanediyl group.

As R <^2> , among these, the group which combined the divalent chain hydrocarbon group, two divalent chain hydrocarbon groups, and one -O- from a viewpoint of improving the receding contact angle at the time of immersion exposure of the formed resist film surface is preferable, More preferably, a divalent linear hydrocarbon group having 1 to 4 carbon atoms or a combination of two 1 to 4 divalent linear hydrocarbon groups with 1 -O- is a divalent linear hydrocarbon group having 2 or 3 carbon atoms or 2 Groups combining a divalent chain hydrocarbon group having 1 to 3 carbon atoms and one -O- are more preferred, and an ethanediyl group, a methanediyloxyethanediyl group, and a methanediyloxy (1,2-propanediyl) group are particularly preferred. The methanediyloxyethanediyl group and the methanediyloxy (1,2-propanediyl) group are more particularly preferable.

If the R ^A is a hydrogen atom, as the -C (R ¹⁾ (OH) (CF ₃₎ In the above general formula (1), such as 2-hydroxy -1,1,1,3,3, 3-hexafluoro-2-propyl group, 1-hydroxy-2,2,2-trifluoroethyl group, 2-hydroxy-1,1,1,4,4,4-hexafluoro-2- Butyl group, 2-hydroxy-1,1,1,3,3,4,4,4-octafluoro-2-butyl group, etc. are mentioned. Among them, 2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl group and 1-hydroxy-2,2,2-trifluoroethyl group are preferable, and 2- More preferred are hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl groups.

As the monovalent organic group having 1 to 20 carbon atoms represented by R ^A, for example, there may be mentioned a monovalent group, and the like of an organic group and the like exemplified as R ¹ and R ^3. Among these, as the monovalent organic group represented by R ^A , a monovalent hydrocarbon group and an acyl group are preferable, an alkyl group and an acyl group are more preferable, and an acyl group is more preferable. Moreover, as said monovalent organic group, a monovalent base dissociable group is also preferable. A "base dissociable group" is group which substitutes the hydrogen atom of a hydroxy group, for example, and dissociates in presence of alkali (for example, in 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution of 23 degreeC). Say the flag.

As said monovalent base dissociable group, group represented by the following general formula (Ba-1), group represented by the following general formula (Ba-2), etc. are mentioned, for example.

In the formulas (Ba-1) and (Ba-2), each of R ^{Ba 's} independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. Some or all of the hydrogen atoms which this hydrocarbon group has may be substituted.

As a C1-C20 monovalent hydrocarbon group represented by said R ^Ba , a C1-C20 monovalent linear hydrocarbon group, a C3-C20 monovalent alicyclic hydrocarbon group, C6-C20 monovalent Aromatic hydrocarbon group etc. are mentioned.

As said C1-C20 monovalent chain hydrocarbon group, C3-C20 monovalent alicyclic hydrocarbon group, C6-C20 monovalent aromatic hydrocarbon group, each of the examples illustrated as said R <^1> and R <^3> is mentioned, for example. The same thing as group etc. are mentioned.

As a substituent of the monovalent hydrocarbon group represented by said R ^Ba , a fluorine atom, a hydroxyl group, an amino group, a mercapto group, a carboxy group, a cyano group, an alkoxy group, an acyl group, an acyloxy group, etc. are mentioned, for example.

As said R ^{Ba, a} monovalent chain hydrocarbon group is preferable, a C1-C5 monovalent chain hydrocarbon group is more preferable, and a methyl group is more preferable.

Examples of the group represented by the general formula (Ba-1) and the group represented by the general formula (Ba-2) include groups represented by the following general formulas.

As R ^{A, a} hydrogen atom and a monovalent base dissociable group are preferable, and a hydrogen atom is more preferable. Since R ^{A is made} into the said group, after alkali image development, it becomes an OH group and since it has high acidity by the electron withdrawing property of the trifluoromethyl group couple | bonded with the (alpha) -carbon of this group, [A] polymer shows high alkali solubility. Thereby, the receding contact angle of the resist film surface after image development can be made smaller. As a result, generation | occurrence | production of the developing defect in the resist pattern formed from the said radiation-sensitive resin composition for immersion exposure can be suppressed more.

As structural unit (I), the structural unit etc. which are represented by following General formula (1-1)-(1-18) are mentioned, for example.

Among these, the structural units represented by the formulas (1-1) to (1-9), (1-13) and (1-16) are preferable, and the formulas (1-1) and (1-2) More preferred are structural units represented by (1-4), (1-5), (1-6) and (1-16), and the above formulas (1-4), (1-5) and (1) More preferred is a structural unit represented by -6).

Further, the structural unit (I) as, for example, in the structural unit represented by the above formula (1-1) to _{(1-18) - (CF 3)} 2 hydrogen atoms of the C-OH group the formula (Ba-1 Or a structural unit substituted with a monovalent base dissociable group represented by the formula (Ba-2).

As content rate of a structural unit (I), 1 mol% or more and 100 mol% or less are preferable with respect to the total structural units which comprise a polymer [A], 10 mol% or more and 98 mol% or less are more preferable, 30 mol% 95 mol% or more is more preferable, and 60 mol% or more and 90 mol% or less are especially preferable. By setting the content ratio of the structural unit (I) in the polymer (A) within the above range, the receding contact angle of the formed resist film can be made larger during immersion exposure, and smaller after development, and development defects can be prevented. Can be further suppressed.

As described later, the polymer (A) is obtained by radical polymerization with a monomer to which other structural units are added, in addition to the monomer to which the structural unit (I) is provided. Synthesis of a compound that gives the structural unit (I) is, R ² is _{^{-R 2a -O- (CH 2) n}} - in the case of a compound (i) include, for example, as follows. R ² is _{^{-R 2a -O- (CH 2) n}} - Examples of the compound that gives the structural unit (I) may be used other than the known compounds. As a well-known compound, the compound of Unexamined-Japanese-Patent No. 2002-220420, Unexamined-Japanese-Patent No. 2002-155112, Unexamined-Japanese-Patent No. 2005-107476, etc. are mentioned, for example.

In said general formula (ia), (ib) and (i), R <^1> is a hydrogen atom or a C1-C20 monovalent organic group. R <^2a> is a C1-C16 bivalent linear hydrocarbon group or group which combined this linear hydrocarbon group with -O-. R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ^A is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. X is a halogen atom. n is an integer of 1-4.

The hydroxy compound represented by the formula (ia) and the haloalkyl acrylate ester compound represented by the formula (ib) are reacted in the presence of a base compound such as triethylamine in a solvent such as dichloromethane to the formula Compound (i) to be represented is obtained. When R ^A is a hydrogen atom, in the compound represented by the formula (ia), the compound (i) can be obtained with good yield since the reactivity of the hydroxy group bonded to the carbon atom adjacent to the CF ₃ group among the two hydroxy groups is low. have. R ^A is a monovalent organic group Compound (i) can also be synthesized by converting the OH group with a compound (i) R ^A is a hydrogen atom in OR ^A.

As a halogen atom represented by said X, a fluorine atom, a halogen atom, a bromine atom, an iodine atom, etc. are mentioned, for example. Among these, a bromine atom is preferable from a viewpoint of reaction yield.

[Structural Unit (II)]

Structural unit (II) is a structural unit containing an acid dissociative group. An "acid dissociable group" is group which substitutes hydrogen atoms, such as a carboxy group and a hydroxyl group, and means the group dissociated by the effect | action of an acid. By having the structural unit (II), the polymer (A) can further suppress the dissolution residue in the developer in the exposed portion. As a result, according to the said radiation sensitive resin composition for immersion exposure, generation | occurrence | production of a development defect can be suppressed further.

As structural unit (II), the structural unit represented by following General formula (2), etc. are mentioned, for example.

In said general formula (2), R <^4> is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ⁵ is an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 4 to 20 carbon atoms. R ⁶ and R ⁷ are each independently an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 4 to 20 carbon atoms, or R ⁶ and R ⁷ are bonded to each other to form a divalent cyclic ring together with the carbon atom to which they are bonded; Forming a group.

As R <^4> , a hydrogen atom and a methyl group are preferable from a viewpoint of the copolymerizability of the monomer which gives a structural unit (II), and a methyl group is more preferable.

As a C1-C6 alkyl group represented by said R <^5> -R <^7> , for example, a methyl group, an ethyl group, n-propyl, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t- Butyl group etc. are mentioned. Among these, methyl group, ethyl group and i-propyl group are preferable.

As a C4-C20 alicyclic hydrocarbon group represented by said R <^5> -R <^7> , For example, Monocyclic cycloalkyl groups, such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group; Polycyclic cycloalkyl groups, such as a norbornyl group and an adamantyl group, etc. are mentioned. Among these, cyclopentyl group, cyclohexyl group, norbornyl group, and adamantyl group are preferable.

As a bivalent cyclic group which said R <^6> and R <^7> combines with each other, they form monocyclic cycloalkanediyl groups, such as a cyclopentanediyl group, a cyclohexanediyl group, and a cyclooctanediyl group; Polycyclic cycloalkanediyl groups such as norbornanediyl and adamantanediyl; Monocyclic divalent aliphatic heterocyclic groups such as an azacyclopentanediyl group and an oxacyclopentanediyl group; Polycyclic divalent aliphatic heterocyclic groups, such as an aza norbornanediyl group and an oxa norbornanediyl group, etc. are mentioned. Of these, a monocyclic cycloalkanediyl group and a polycyclic cycloalkanediyl group are preferable, a cyclopentanediyl group, a cyclohexanediyl group, a cyclooctanediyl group, a norbornanediyl group and an adamantanediyl group are more preferable, and a cyclo Pentanediyl group and an adamantanediyl group are more preferable.

As structural unit (II), the structural unit which has an alkanediyl group which R <^6> and R <^7> combines with each other, and is formed is preferable, and a structural unit derived from 1-alkyl-1-cycloalkyl (meth) acrylate, 2- The structural unit derived from alkyl-2-adamantyl (meth) acrylate is more preferable, the structural unit derived from 1-alkyl-1-cycloalkyl (meth) acrylate is more preferable, and 1-alkyl-1 The structural unit derived from -cyclopentyl (meth) acrylate is especially preferable, and the structural unit derived from 1-methyl-1-cyclopentyl (meth) acrylate is more especially preferable.

As a monomer which gives a structural unit (II), it is a monomer represented by following General formula (2-1)-(2-11) (it is also called "monomer (2-1)-(2-11)" hereafter.) ), And the like.

Among the above monomers, monomers (2-2), (2-3), (2-4), (2-9) and (2-10) are preferable, and monomer (2-2) is more preferable.

As content rate of a structural unit (II), 5 mol% or more and 90 mol% or less are preferable with respect to the total structural units which comprise the [A] polymer, 8 mol% or more and 60 mol% or less are more preferable, 10 mol% 40 mol% or more is more preferable. By making the content rate of a structural unit (II) into the said range, the said liquid immersion exposure radiation sensitive resin composition can further suppress the melt | dissolution residue with respect to the developing solution of the polymer [A] in an exposure part, As a result, a development defect Can be further suppressed.

[Structural Unit (III)]

Structural unit (III) is a structural unit containing a fluorine atom (except corresponding to structural unit (I)). The polymer [A] does not necessarily require the structural unit (III) because the structural unit (I) contains a fluorine atom, but the polymer [A] can further increase the fluorine atom content by further having the structural unit (III). As a result, localization to the resist surface layer can be promoted.

As said structural unit (III), the structural unit represented by the said General formula (3-1) (henceforth also called "the structural unit (III-1)"), and the structural unit represented by General formula (3-2) (Hereinafter also referred to as "structural unit (III-2)"), a structural unit represented by the formula (3-3) (hereinafter also referred to as "structural unit (III-3)"), and the like.

In said general formula (3-1), R <^8> is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R <^9> is a C1-C6 linear or branched alkyl group which has a fluorine atom, or a C4-C20 monovalent alicyclic hydrocarbon group which has a fluorine atom. However, one part or all part of the hydrogen atom which the said alkyl group and alicyclic hydrocarbon group have may be substituted.

In said general formula (3-2), R <^10> is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ¹¹ is a (k + 1) valence group. k is an integer of 1-3. X is a divalent linking group having a fluorine atom. R ¹² is a hydrogen atom or a monovalent organic group. However, when k is 2 or 3, some X and R <^12> may be same or different, respectively.

In said general formula (3-3), R <^13> is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R <^14> is a coupling group which does not have a (m + 1) valent fluorine atom. m is an integer of 1-3. A ¹ is -COO-. R ¹⁵ is a monovalent hydrocarbon group containing at least one fluorine atom. However, when m is 2 or 3, some A <^1> and R <^15> may be same or different, respectively.

As a C1-C6 linear or branched alkyl group which has a fluorine atom represented by said R <^9> , For example, C1-C6 linear or branched alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, etc. The group etc. which substituted one part or all part of the hydrogen atom which has the thing with the fluorine atom are mentioned.

As a C4-C20 monovalent alicyclic hydrocarbon group which has a fluorine atom represented by said R <^9> , For example, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, norbornyl group, adamantyl group, The group etc. which substituted one part or all part of the hydrogen atom which C4-C20 monovalent alicyclic hydrocarbon group, such as a cyclopentylmethyl group and a cyclohexylmethyl group, substituted with the fluorine atom are mentioned.

Examples of the (k + 1) valent linking group represented by R ¹¹ include a linear or branched hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and an aromatic hydrocarbon group having 6 to 30 carbon atoms. Or a group obtained by combining these groups with at least one group selected from the group consisting of -O-, -S-, -NH-, -CO- and -CS-. In addition, the (k + 1) -valent linking group may have a substituent.

Examples of the linear or branched hydrocarbon group having 1 to 30 carbon atoms include (k + 1) from hydrocarbon groups such as methane, ethane, propane, butane, pentane, hexane, heptane, decane, icosane and triacontane. And groups in which) hydrogen atoms are removed.

As said C3-C30 alicyclic hydrocarbon group, it is, for example

Monocyclic saturated hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane and ethylcyclohexane;

Monocyclic unsaturated hydrocarbons such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene;

Bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [3.3.1.1 ^3,7 ] decane, tetracyclo [6.2.1.1 ^{3, 6.0 2,7]} dodecane, adamantane polycyclic saturated hydrocarbons, such as carbon;

Bicyclo [2.2.1] heptene, bicyclo [2.2.2] octene, tricyclo [5.2.1.0 ^2,6 ] decene, tricyclo [3.3.1.1 ^3,7 ] decene, tetracyclo [6.2.1.1 ^{3, 6.0 2,7]} dodecene, etc. the removal of the group from a cyclic hydrocarbon (k + 1) hydrogen atoms of the like can be given.

As said C6-C30 aromatic hydrocarbon group, For example, from aromatic hydrocarbons, such as benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, pisene, toluene, xylene, ethylbenzene, mesitylene, cumene, The group remove | excluding k + 1) hydrogen atom, etc. are mentioned.

As a bivalent coupling group which has a fluorine atom represented by said X, the C1-C20 bivalent linear hydrocarbon group which has a fluorine atom, the bivalent group which combined this group and the carbonyl group, etc. are mentioned, for example. As said X, group etc. which are represented by following General formula (X-1)-(X-7) are mentioned, for example.

As X, group represented by the said general formula (X-7) among these is preferable.

Examples of the monovalent organic group represented by R ¹² include a linear or branched hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, or these The group which combined 1 or more types chosen from the group which consists of group, an oxygen atom, a sulfur atom, an ether group, ester group, a carbonyl group, an imino group, and an amide group, etc. are mentioned.

As a linking group which does not have a (m + 1) valent fluorine atom represented by said R <^14> , For example, a C1-C30 linear or branched hydrocarbon group, C3-C30 alicyclic hydrocarbon group, C6-C6 An aromatic hydrocarbon group of 30 or a hydrocarbon group of 1 to 30 carbon atoms -CO-, -COO-, -OCO-, -O-, -NR-, -CS-, -S-, -SO- and -SO _2- The group etc. which combined 1 or more types chosen from the group which consists of these are mentioned. As a linking group which does not have a (m + 1) valent fluorine atom represented by said R <^13> , it is the same as that which does not have a fluorine atom among the groups illustrated as a (k + 1) valent coupling group represented by said R <^11> , for example. And the like can be mentioned.

As a monovalent hydrocarbon group containing at least 1 fluorine atom represented by said R <^15> , a fluorinated alkyl group, a fluorinated alicyclic hydrocarbon group, a fluorinated aromatic hydrocarbon group, etc. are mentioned, for example.

As a monomer which gives a structural unit (III-1), for example, trifluoromethyl (meth) acrylate, 2,2,2- trifluoroethyl (meth) acrylate, and perfluoroethyl (meth) acryl Laterate, perfluoro n-propyl (meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, Perfluoro t-butyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1 -(2,2,3,3,4,4,5,5-octafluoro) pentyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro Ro) hexyl (meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2, 2,3,3,4,4,4-heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8, 9,9,1 0,10,10-heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl ( Meth) acrylate, and the like.

As a monomer which gives a structural unit (III-2), it is (meth) acrylic acid 2- (1-ethoxycarbonyl-1,1-difluoro) butyl ester, (meth) acrylic acid 2- (1- t-butoxycarbonyl-1,1-difluoro) butyl ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester , (Meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2 -Trifluoromethyl-2-hydroxy-4-cyclohexyl-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-5 -Pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic acid 2-{[5- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester and the like. Among them, (meth) acrylic acid 2- (1-t-butoxycarbonyl-1,1-difluoro) butyl ester and (meth) acrylic acid 2- (1-ethoxycarbonyl-1,1-difluoro Butyl ester is preferred.

As a monomer which gives a structural unit (III-3), it is (meth) acrylic acid 2- (1,1,1,3,3,3-hexafluoro-2- propoxycarbonyl) norbornane lacto, for example. Nylester, (meth) acrylic acid 2- (2,2,2-trifluoroethoxycarbonyl) norbornanelactonyl ester, (meth) acrylic acid 4- (1,1,1,3,3,3- Hexafluoro-2-propoxycarbonyl) cyclohexyl ester, (meth) acrylic acid 4- (2,2,2-trifluoroethoxycarbonyl) cyclohexyl ester, and the like.

As the structural unit (III), for example, the following formulas (3-1-1) to (3-1-6), formulas (3-2-1) to (3-2-3) and formulas (3-3) The structural unit represented by -1), etc. are mentioned.

In said general formula (3-1-1)-(3-1-6), R <^8> is synonymous with said general formula (3-1). R <^10> is synonymous with the said General formula (3-2) in the said General formula (3-2-1)-(3-2-3). R <^13> is synonymous with the said General formula (3-3) in the said General formula (3-3-1).

Among these, the structural unit represented by the said General formula (3-1-1) and the structural unit represented by General formula (3-1-3) are preferable.

As content rate of a structural unit (III), 0 mol% or more and 90 mol% or less are preferable with respect to the total structural units which comprise [A] polymer, and 0 mol% or more and 50 mol% or less are more preferable.

The polymer (A) may have one or more types of other structural units other than the structural units (I) to (III). As content rate of another structural unit, 30 mol% or less is preferable and 20 mol% or less is more preferable.

As content of the polymer (A), 0.1 mass% or more and 50 mass% or less are preferable with respect to the total solid of the said radiation-sensitive resin composition for immersion exposure, 0.1 mass% or more and 20 mass% or less are more preferable, 0.5 mass% or more 15 mass% or less is more preferable, and 1 mass% or more and 10 mass% or less are especially preferable.

As content of a polymer, 0.1 mass part or more and 20 mass parts or less are preferable with respect to 100 mass parts of [C] polymers mentioned later, 0.5 mass parts or more and 15 mass parts or less are more preferable, 1 mass part or more and 10 mass parts or less Part or less is more preferable.

<Synthesis method of polymer [A]>

The polymer (A) can be synthesized, for example, by polymerizing a monomer giving each of the predetermined structural units in a suitable solvent using a radical polymerization initiator.

As a method of a polymerization reaction, for example, the method of carrying out the polymerization reaction by dropwise adding the solution containing a monomer and a radical initiator to the reaction solvent or the solution containing a monomer; A method in which a solution containing a monomer and a solution containing a radical initiator are respectively added dropwise to a reaction solvent or a solution containing a monomer and polymerized; The method etc. which carry out the polymerization reaction by dripping several types of solution containing each monomer and the solution containing a radical initiator separately to the reaction solvent or the solution containing a monomer, etc. are mentioned.

Examples of the radical initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) and 2,2 '. -Azobis (2-cyclopropyl propionitrile), 2,2'- azobis (2,4-dimethylvaleronitrile), 2,2'- azobisisobutyrate dimethyl, etc. are mentioned. These radical initiators can be used in mixture of 2 or more type.

As a solvent used for the said superposition | polymerization, for example,

alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane;

Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin and norbornane;

Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and cumene;

Halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide and chlorobenzene;

Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate and methyl propionate;

Ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone;

Ethers such as tetrahydrofuran, dimethoxyethanes and diethoxyethanes;

Alcohol, such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl- 2-pentanol, etc. are mentioned. In addition, these solvent can also use 2 or more types together.

In the polymerization reaction for synthesizing the polymer (A), a molecular weight modifier can be used to adjust the molecular weight. As a molecular weight modifier, For example, Halogenated hydrocarbons, such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan and thioglycolic acid; Xanthogens such as dimethyl xanthogen sulfide and diisopropyl xanthogen disulfide; Terpinolene, the (alpha) -methylstyrene dimer, etc. are mentioned.

As reaction temperature in the said superposition | polymerization, it is 40 degreeC-150 degreeC normally, Preferably it is 50 degreeC-120 degree | times. The reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.

The polymer obtained by the polymerization reaction can be recovered by the reprecipitation method. As the reprecipitation solvent, an alcohol solvent or the like can be used.

As polystyrene reduced weight average molecular weight (Mw) by gel permeation chromatography (GPC) of the polymer (A), 1,000 or more and 50,000 or less are preferable, 2,000 or more and 30,000 or less are more preferable, 3,000 or more and 15,000 or less are more preferable, 3,000 10,000 or more are especially preferable. By setting Mw of the polymer (A) in the above range, localization of the polymer (A) to the resist film surface layer can be promoted, and as a result, the radiation-sensitive resin composition for immersion exposure immerses the receding contact angle of the resist film formed. It can make it larger at the time of exposure, and can make it smaller after image development.

As ratio (Mw / Mn) of Mw of a polymer and polystyrene conversion number average molecular weight (Mn) by GPC method, 1 or more and 5 or less are preferable, 1 or more and 3 or less are more preferable, 1 or more and 2 or less It is preferable and 1.2 or more and 1.6 or less are especially preferable.

In addition, Mw and Mn of the polymer in this specification are measured by GPC by the following conditions.

Columns: 2 G2000HXL, 1 G3000HXL, and 1 G4000HXL (Sold)

Mobile phase: tetrahydrofuran

Column temperature: 40 ℃

Flow rate: 1.0mL / min

Sample concentration: 1.0 mass%

Sample injection volume: 100 μL

Detector: parallax refractometer

Standard material: monodisperse polystyrene

<[B] acid generator>

An acid generator (B) generates an acid by exposure, dissociates the acid dissociable group which the [A] polymer, the polymer [C] mentioned later, etc. have by this acid, and produces | generates a carboxyl group. As a result, the polarity of these polymers increases, and the polymer in the exposed portion becomes soluble to the alkaline developer. As a containing form of the acid generator [B] in the radiation sensitive resin composition for liquid immersion exposure, the form of the compound (hereinafter referred to as "[B] acid generator" as appropriate) may also be a part of a polymer. It may be in the form inserted as, or both.

Examples of the acid generator (B) include an onium salt compound, an N-sulfonyloxyimide compound, a halogen-containing compound, a diazoketone compound, and the like.

As an onium salt compound, a sulfonium salt, tetrahydrothiophenium salt, an iodonium salt, a phosphonium salt, a diazonium salt, a pyridinium salt, etc. are mentioned, for example.

As the sulfonium salt, for example, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (1-adamantyl) -1,1-difluoro Roethanesulfonate, 4-cyclohexylphenyldiphenylsulfoniumtrifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium purple Fluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4- Methanesulfonylphenyldiphenylsulfoniumtrifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfo Perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, Triphenylsulfonium 1,1,2,2-tetrafluoro-6- (1-adamantylcarbonyloxy) -hexane-1-sulfonate, and the like.

As the tetrahydrothiophenium salt, for example, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiopheniumtrifluoromethanesulfonate and 1- (4-n-butoxynaphthalene-1- 1) tetrahydrothiopheniumnonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiopheniumperfluoro-n-octanesulfonate, 1- ( 4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- ( 6-n-butoxynaphthalen-2-yl) tetrahydrothiopheniumtrifluoromethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiopheniumnonafluoro-n- Butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiopheniumperfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetra Hydrothiophenium2-bicyclo [2.2.1] hepto-2-yl-1,1,2,2-tetrafluoroethanesulfonei , 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiopheniumtrifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nona Fluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiopheniumperfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4- Hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, and the like.

Examples of iodonium salts include diphenyl iodonium trifluoromethanesulfonate, diphenyl iodonium nonafluoro-n-butanesulfonate, diphenyl iodonium perfluoro-n-octane sulfonate, Diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodoniumtrifluoro Methanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis ( 4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate etc. are mentioned.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyimide and N- (nonnafluoro -n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyimide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] Hept-5-ene-2,3-dicarboxyimide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyimide, and the like.

Among these, an onium salt compound is preferable, a sulfonium salt is more preferable, triphenylsulfonium perfluoroalkanesulfonate is more preferable, and triphenylsulfonium nona-n-butanesulfonate is particularly preferable.

[B] As content of an acid generator, as content when the [B] acid generator is an acid generator, 100 mass parts of [A] polymers from a viewpoint of ensuring the sensitivity and developability of the radiation sensitive resin composition for immersion exposure. 0.5 mass parts or more and 20,000 mass parts or less are preferable, 5 mass parts or more and 10,000 mass parts or less are more preferable, 10 mass parts or more and 1,000 mass parts or less are more preferable, 50 mass parts or more and 500 mass parts or less are especially preferable. desirable.

Moreover, as content of the [B] acid generator, 0.1 mass part or more and 20 mass parts or less with respect to 100 mass parts of [C] polymers mentioned later from a viewpoint of ensuring the sensitivity and developability of the radiation sensitive resin composition for immersion exposure. It is preferable, 0.5 mass part or more and 17 mass parts or less are more preferable, and 1 mass part or more and 15 mass parts or less are more preferable.

By making content of the acid generator (B) into the said range, the sensitivity and developability of the radiation sensitive resin composition for immersion exposure can be improved. The acid generator (B) can be used individually by 1 type or in mixture of 2 or more types.

<[C] polymer>

The polymer [C] is a polymer having a smaller content of fluorine atoms than the polymer [A] and a polymer having an acid dissociable group. The polymer (C) is a polymer that becomes a base polymer in the radiation-sensitive resin composition for liquid immersion exposure. In addition, a "base polymer" means the polymer which becomes a main component of the polymer which comprises the resist film formed from a radiation sensitive resin composition, Preferably it means the polymer which occupies 50 mass% or more with respect to the whole polymer which comprises a resist film.

Since the content of the fluorine atom of the polymer [C] is smaller than the content of the fluorine atom of the polymer [A], it can be effectively localized in the resist film surface layer on which the [A] polymer is formed, and as a result, the radiation-sensitive resin composition for immersion exposure is The receding contact angle of the formed resist film can be made larger during immersion exposure and smaller after development.

As a fluorine atom content rate of [C] polymer, less than 5 mass% is preferable, 3 mass% or less is more preferable, and 1 mass% or less is more preferable.

[C] The polymer has a structural unit containing an acid dissociable group (hereinafter also referred to as "structural unit (C-II)"), and in addition to this structural unit, for example, a lactone structure, a cyclic carbonate structure, and a sultone structure It is preferable to have a structural unit (henceforth "structural unit (IV)") which has at least 1 sort (s) of structure chosen from the group which consists of these, and may have other structural units other than these structural units. The polymer (C) may have one or two or more structural units. Hereinafter, each structural unit is demonstrated.

[Structural Unit (C-II)]

The polymer [C] has a structural unit (C-II), whereby the acid dissociable group is dissociated by the action of an acid generated from the acid generator [B] to generate a carboxyl group or the like. As a result, the polymer [C] has a changed polarity and a change in solubility in an alkaline developer.

Although it does not specifically limit as a structural unit (C-II) as long as it has an acid dissociable group, For example, the structural unit (II) in the polymer [A] mentioned above, etc. are mentioned.

As a structural unit (C-II), the structural unit derived from 1-alkyl-1-cycloalkyl (meth) acrylate, and the structural unit derived from 2-alkyl-2-adamantyl (meth) acrylate are preferable, The structural unit derived from 1-alkyl-1-cyclopentyl (meth) acrylate and the structural unit derived from 2-alkyl-2-adamantyl (meth) acrylate are more preferable, and 1-methyl-1- Structural unit derived from cyclopentyl (meth) acrylate, Structural unit derived from 1-ethyl-1-cyclopentyl (meth) acrylate, and derived from 1-i-propyl-1-cyclopentyl (meth) acrylate The structural unit derived from a structural unit, 2-methyl-2-adamantyl (meth) acrylate, and the structural unit derived from 2-ethyl-2-adamantyl (meth) acrylate are more preferable.

As a monomer which gives a structural unit (C-II), in the thing illustrated as a monomer which gives the structural unit (II) of the said [A] polymer, monomer (2-2), (2-3), (2- 4), (2-9) and (2-10) are preferred.

As content rate of a structural unit (C-II), 10 mol% or more and 90 mol% or less are preferable with respect to the total structural units which comprise a [C] polymer, More preferably, 30 mol% or more and 80 mol% or less, 40 More preferably, mol% or more and 70 mol% or less. By making the content rate of a structural unit (C-II) into the said range, the pattern formation property of the radiation sensitive resin composition for immersion exposure can be improved.

[Structural Unit (IV)]

Structural unit (IV) is a structural unit containing at least 1 sort (s) of structure chosen from the group which consists of a lactone structure, a cyclic carbonate structure, and a sultone structure. When a polymer (C) has a structural unit (IV), adhesiveness with respect to the board | substrate of the resist film formed from the said radiation sensitive resin composition for immersion exposure can be improved.

As a monomer which gives a structural unit (IV), the monomer etc. which are represented by following General formula (4-1)-(4-14) are mentioned, for example.

Among the above monomers, monomer (4-1), monomer (4-2) and monomer (4-3) are preferable, and monomer (4-1) is more preferable.

As content rate of a structural unit (IV), 10 mol% or more and 80 mol% or less are preferable with respect to the total structural units which comprise a [C] polymer, 20 mol% or more and 70 mol% or less are more preferable, 30 mol% More than 60 mol% or less is more preferable. By making the content rate of a structural unit (IV) into the said range, adhesiveness with the board | substrate of the resist film formed from the said radiation sensitive resin composition for immersion exposure can be improved.

[Other structural units]

[C] The polymer may have, for example, a structural unit containing a polar group as other structural units other than the structural unit (C-II) and the structural unit (IV). As a polar group, a carboxy group, a hydroxyl group, a cyano group, a nitro group, a sulfonamide group, etc. are mentioned, for example. Of these, carboxyl groups and hydroxyl groups are preferred. As content rate of another structural unit, 30 mol% or less is preferable with respect to the total structural unit which comprises [C] polymer, and 20 mol% or less is more preferable.

As content of the [C] polymer, 500 mass parts or more and 10,000 mass parts or less are preferable with respect to 100 mass parts of [A] polymers, 700 mass parts or more and 7,000 mass parts or less are more preferable, 1,000 mass parts or more and 4,000 mass parts or less More preferred.

As content of the polymer (C), 70 mass% or more is preferable with respect to the total solid of the radiation sensitive resin composition for immersion exposure, 75 mass% or more is more preferable, and 80 mass% or more is more preferable.

<Synthesis method of polymer [C]>

The polymer [C] can be synthesized by the same method as the synthesis method of the polymer [A] described above, using a monomer giving a predetermined structural unit.

As Mw of a polymer (C), 1,000 or more and 50,000 or less are preferable, 2,000 or more and 30,000 or less are more preferable, 3,000 or more and 15,000 or less are more preferable, 3,000 or more and 10,000 or less are especially preferable. By making Mw of a polymer (C) into the said specific range, the said radiation sensitive resin composition for immersion exposure can improve lithographic performance, such as a sensitivity and a resolution.

As Mw / Mn of [C] polymer, 1 or more and 5 or less are preferable, 1 or more and 3 or less are more preferable, 1 or more and 2 or less are more preferable, 1.2 or more and 1.6 or less are especially preferable. By setting Mw / Mn of the polymer (C) in the above range, the radiation sensitive resin composition for immersion exposure can improve lithography performance such as sensitivity and resolution.

<[D] acid diffusion control body>

It is preferable that the said radiation sensitive resin composition for immersion exposure further contains the [D] acid diffusion control body. The acid diffusion control agent (D) controls the diffusion phenomenon in the resist film of the acid generated from the acid generator [B] by exposure, and exhibits an effect of suppressing undesirable chemical reaction in the non-exposed areas. do. Therefore, the said liquid immersion exposure radiation sensitive resin composition can further contain the [D] acid diffusion control body, and can improve lithographic performances, such as resolution, while maintaining the characteristics, such as the receding contact angle mentioned above. As a containing form of the [D] acid diffusion controller in the radiation sensitive resin composition for liquid immersion exposure, it may be a form of a compound (hereinafter referred to as "[D] acid diffusion control agent" as appropriate) as described later. It may be in the form of being inserted as a part of or both of them.

Examples of the acid diffusion control agent (D) include N-t-alkoxycarbonyl group-containing amino compounds, tertiary amine compounds, quaternary ammonium hydroxide compounds and the like.

Examples of the Nt-alkoxycarbonyl group-containing amino compound include Nt-butoxycarbonyldi-n-octylamine, Nt-amyloxycarbonyldi-n-octylamine, and Nt-butoxycarbonyldi-n-nonylamine , Nt-amyloxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-amyloxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine , Nt-amyloxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-amyloxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-a Monomethylamine, Nt-amyloxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-amyloxycarbonyl-N-methyl-1-a Monodylamine, (S)-(-)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (S)-(-)-1- (t-amyloxycarbonyl) -2 -Pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-amyloxycarbono ) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonylpyrrolidine, Nt Amyloxycarbonylpyrrolidine, N, N'-di-t-butoxycarbonylpiperazine, N, N'-di-t-amyloxycarbonylpiperazine, N, N-di-t-part Oxycarbonyl-1-adamantylamine, N, N-di-t-amyloxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt Amyloxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N'-di-t-amyloxycarbonylhexamethylenediamine , N, N, N ', N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N, N', N'-tetra-t-amyloxycarbonylhexamethylenediamine, N, N'- Di-t-butoxycarbonyl-1,7-diaminoheptane, N, N'-di-t-amyloxycarbonyl-1,7-diaminoheptane, N, N'-di-t-butoxy Carbonyl-1,8-diaminooctane, N, N'-di-t-a Oxycarbonyl-1,8-diaminooctane, N, N'-di-t-butoxycarbonyl-1,9-diaminononane, N, N'-di-t-amyloxycarbonyl-1 , 9-diaminononane, N, N'-di-t-butoxycarbonyl-1,10-diaminodecane, N, N'-di-t-amyloxycarbonyl-1,10-diamino Decane, N, N'-di-t-butoxycarbonyl-1,12-diaminododecane, N, N'-di-t-amyloxycarbonyl-1,12-diaminododecane, N, N'-di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-amyloxycarbonyl-4,4'-diaminodiphenylmethane, Nt- Butoxycarbonylbenzimidazole, Nt-butoxycarbonylbenzimidazole, Nt-amyloxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, Nt-amyloxy Carbonyl-2-phenyl benzimidazole etc. are mentioned.

As said tertiary amine compound, it is, for example

Triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, cyclohexyldimethylamine Tri (cyclo) alkylamines such as dicyclohexylmethylamine and tricyclohexylamine;

Aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline, etc. Aromatic amines;

Alkanolamines such as triethanolamine and N, N-di (hydroxyethyl) aniline;

N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl ) -1-methylethyl] benzene tetramethylenediamine, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, etc. are mentioned.

As said quaternary ammonium hydroxide compound, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, etc. are mentioned, for example.

Among these, Nt-alkoxycarbonyl group-containing amino compounds are preferable, Nt-alkoxycarbonyl group-containing cyclic amine compounds are more preferable, Nt-alkoxycarbonyl-4-hydroxypiperidine is more preferable, and Nt-amyloxycarbonyl 4-hydroxypiperidine is particularly preferred.

As the acid diffusion control agent (D), an onium salt compound that decomposes upon exposure and loses basicity as acid diffusion controllability may be used. As such an onium salt compound, the sulfonium salt compound represented by following General formula (5-1), the iodonium salt compound represented by General formula (5-2), etc. are mentioned, for example.

In said Formula (5-1) and Formula (5-2), R <^16> -R <^20> is respectively independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, or a halogen atom. Z ^- and E ^- is an anion, or to represent by formula ⁽⁶⁾ is ^{OH -, R 21 -COO -,} R 21 -SO 3. R ²¹ is each independently an alkyl group, an aryl group, or an aralkyl group.

Examples of the sulfonium salt compound and iodonium salt compound include triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, Diphenyl-4-hydroxyphenylsulfonium acetate, diphenyl-4-hydroxyphenylsulfonium salicylate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl Iodonium acetate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium salicylate 4-t-butylphenyl-4-hydroxyphenyl iodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyl iodonium acetate, 4-t-butylphenyl-4-hydroxyphenyl Iodonium salicylate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, diphenyliodonium 10-camphorsulfonate, triphenylsulfonium 10-camphorsulfonate, 4-t -Butoxyphenyl diphenylsulfonium 10-camphorsulfonate, etc. are mentioned.

As content of the [D] acid diffusion control body, when [D] acid diffusion control body is an [D] acid diffusion control agent, 20,000 mass parts or less are preferable with respect to 100 mass parts of [A] polymers, 5 mass parts or more and 10,000 mass parts Part or less is more preferable, 10 mass parts or more and 1,000 mass parts or less are more preferable, 50 mass parts or more and 500 mass parts or less are especially preferable.

Moreover, as content of the [D] acid diffusion control agent, 0.1 mass part or more and 20 mass parts or less are preferable with respect to 100 mass parts of [C] polymers, 0.5 mass part or more and 17 mass parts or less are more preferable, 1 mass part 15 mass parts or more are more preferable.

By making content of the acid diffusion control agent (D) into the said range, the shape of the resist pattern obtained from the said radiation sensitive resin composition for immersion exposure improves. The acid diffusion control agent (D) may be used alone or in combination of two or more.

<[E] solvent>

The radiation sensitive resin composition for liquid immersion exposure usually contains the solvent [E]. [E] The solvent is particularly limited as long as it can dissolve or disperse the [A] polymer, the [B] acid generator, the [C] polymer, the [D] acid diffusion controller and other optional components contained as necessary. It doesn't work. Examples of the solvent (E) include alcohols, ethers, ketones, amides, esters, and the like. The solvent (E) may be used alone or in combination of two or more thereof.

As alcohols, for example

Methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert- Pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec- tetradecyl alcohol, sec-heptadecyl alcohol, green Monoalcohols such as furyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol and diacetone alcohol;

Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, Polyhydric alcohols such as 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;

Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol mono Methyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene Polyhydric alcohol partial ethers, such as glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and dipropylene glycol monopropyl ether, etc. are mentioned.

As ethers, for example

Dialkyl ethers such as diethyl ether, dipropyl ether and dibutyl ether;

Aromatic ring-containing ethers such as diphenyl ether and anisole;

Cyclic ethers, such as tetrahydrofuran and tetrahydropyran, etc. are mentioned.

As ketones, for example

Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl Chain ketones such as ketones, di-iso-butyl ketones and trimethyl nonanones;

Cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone;

Diketones such as 2,4-pentanedione and acetonyl acetone;

Aromatic ring containing ketones, such as acetophenone, are mentioned.

As amides, for example

Chain amides such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide ;

Cyclic amides, such as N, N'- dimethyl imidazolidinone and N-methylpyrrolidone, etc. are mentioned.

As esters, for example

Methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl acetate Acetic acid esters such as pentyl, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate and ethyl acetoacetate;

Ethylene Glycol Monomethyl Ether, Ethylene Glycol Monoethyl Ether, Diethylene Glycol Monomethyl Ether, Diethylene Glycol Monoethyl Acetate, Diethylene Glycol Mono-n-butyl Ether, Propylene Glycol Monomethyl Ether, Propylene Acetate Acetate esters of polyhydric alcohol partial ethers, such as glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether;

Glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, Diethyl malonate, dimethyl phthalate, diethyl phthalate and the like;

lactones such as γ-butyrolactone and γ-valerolactone;

Carbonates, such as diethyl carbonate and a propylene carbonate, etc. are mentioned.

As hydrocarbons, for example

aliphatic such as n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane, methylcyclohexane Hydrocarbons;

Benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene, n Aromatic hydrocarbons, such as amyl naphthalene, etc. are mentioned.

Of these, esters and ketones are preferable, acetic acid esters of cyclic alcohol partial ethers, cyclic ketones, and lactones are more preferable, and propylene glycol monomethyl ether, cyclohexanone, and γ-butyrolactone are more preferable. .

<Other optional ingredients>

The said radiation sensitive resin composition for immersion exposure may contain other arbitrary components, such as surfactant and a sensitizer, in addition to the said [A]-[E] component. The said radiation sensitive resin composition for immersion exposure may contain 1 type (s) or 2 or more types of other arbitrary components, respectively.

[Surfactants]

Surfactant has the effect of improving the coating property, striation, developability, etc. of the radiation sensitive resin composition for liquid immersion exposure. As surfactant, For example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethyleneglycol dilau And nonionic surfactants such as polyethylene glycol distearate and the like. As a commercial item, it is KP341 (Shin-Etsu Chemical Co., Ltd. make), polyflow No.75, polyflow No., for example. 95 (above, Kyoesha Chemical Co., Ltd.), F-Top EF301, F-Top EF303, F-Top EF352 (above, made by Tochem Products), Mega Face F171, East F173 (More, made by DIC), Florade FC430, East FC431 (Above, Sumitomo 3M), Asahi Guard AG710, Suplon S-382, East SC-101, East SC-102, East SC-103, East SC-104, East SC-105, East SC-106 And Asahi Glass Co., Ltd.) may be mentioned.

[Sensitizer]

A sensitizer exhibits the effect | action which increases the production | generation amount of an acid generator [B], and exhibits the effect which improves the "apparent sensitivity" of the said radiation sensitive resin composition for immersion exposure. Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rosebengal, pyrenes, anthracenes, phenothiazines, and the like.

<The manufacturing method of the radiation sensitive resin composition for immersion exposure>

The radiation sensitive resin composition for liquid immersion exposure may be, for example, a polymer [A], an acid generator [B], a polymer [C], an acid diffusion control agent, an solvent [E], and optionally any other. It can manufacture by mixing a component by predetermined ratio. In this case, it is preferable to filter the obtained liquid mixture with the filter of about 0.20 micrometer in pore size. As solid content concentration of the radiation sensitive resin composition for immersion exposure, 0.1 mass% or more and 50 mass% are preferable, 0.5 mass% or more and 30 mass% or less are more preferable, and 1 mass% or more and 10 mass% or less are more preferable.

<Radiation Resin Composition>

The radiation sensitive resin composition of the present invention,

[A] a polymer having a structural unit represented by the formula (1),

[B] a radiation sensitive acid generator, and

[C] A polymer having a lower content of fluorine atoms than a polymer [A]

Containing,

This [C] polymer has an acid dissociable group.

According to the said radiation sensitive resin composition, the receding contact angle of the resist film surface can be made larger, it can be made smaller after image development, and generation | occurrence | production of a development defect can be suppressed.

<Resist Pattern Forming Method>

The resist pattern forming method,

A step of forming a resist film from the above-mentioned liquid immersion exposure radiation sensitive resin composition (hereinafter also referred to as a "resist film forming step"),

A step of immersion exposing the resist film through a liquid for immersion exposure (hereinafter also referred to as "immersion exposure process"), and

Process of developing the said immersion exposed resist film (henceforth a "development process")

Has

According to the said resist pattern formation method, since the above-mentioned radiation sensitive resin composition for immersion exposure is used, the resist pattern with few developing defects can be formed, while speeding up scanning exposure. Hereinafter, each process is demonstrated.

[Resist Film Forming Step]

In this process, a resist film is formed on a board | substrate using the said radiation sensitive resin composition for immersion exposure. As the substrate, for example, a conventionally known substrate such as a silicon wafer or a wafer coated with aluminum can be used. For example, an organic or inorganic lower layer antireflection film disclosed in Japanese Patent Application Laid-Open No. Hei 6-12452, Japanese Patent Application Laid-Open No. 59-93448, or the like may be formed on a substrate.

As a coating method, rotational coating (spin coating), casting | flow_spread coating, roll coating, etc. are mentioned, for example. Moreover, as a film thickness of the resist film formed, 10 nm or more and 300 nm or less are preferable, 30 nm or more and 200 nm or less are more preferable, 50 nm or more and 150 nm or less are more preferable.

After apply | coating the said radiation sensitive resin composition for liquid immersion exposure, you may volatilize the solvent in a coating film by soft baking (SB) as needed. Although it selects suitably as SB temperature according to the compounding composition of the radiation sensitive resin composition for immersion exposure, 30 to 200 degreeC is preferable and 50 to 150 degreeC is more preferable. As SB time, 5 second-600 second are preferable, and 10 second-300 second are more preferable.

Exposure process

In this step, the resist film formed in the exposure step is immersed through a liquid for immersion exposure. This immersion exposure is performed through a predetermined mask and a liquid for immersion exposure. As this liquid immersion exposure liquid, water, a fluorine-type inert liquid, etc. are mentioned, for example. The liquid for immersion exposure is transparent with respect to the exposure wavelength, and a liquid whose temperature coefficient of refractive index is as small as possible so as to minimize distortion of the optical image projected on the film is preferable. In the case where the exposure light source is ArF excimer laser light (wavelength 193 nm), in addition to the above-described viewpoints, water is preferable from the viewpoints of availability and ease of handling. In the case of using water, an additive which reduces the surface tension of the water and at the same time increases the surface active force may be added in a very small proportion. It is preferable that this additive does not dissolve the resist film on the wafer and can ignore the influence on the optical coating on the lower surface of the lens. As water to be used, distilled water is preferable.

As radiation used for exposure, although it selects suitably according to the kind of [B] acid generator, For example, electromagnetic waves, such as an ultraviolet-ray, an ultraviolet-ray, X-rays, (gamma) rays; Charged particle beams, such as an electron beam and an alpha ray, etc. are mentioned. Among these, far ultraviolet rays are preferable, ArF excimer laser light and KrF excimer laser light (wavelength 248 nm) are more preferable, and ArF excimer laser light is more preferable. Exposure conditions, such as an exposure amount, are suitably selected according to the compounding composition of the said radiation sensitive resin composition for immersion exposure, the kind of additive, etc. In the said resist pattern formation method, you may have an exposure process in multiple times, and the several times of exposure may use the same light source, or may use another light source, but it is preferable to use ArF excimer laser light for the 1st exposure.

It is preferable to perform post-exposure baking (PEB) after the said exposure. By performing PEB, the dissociation reaction of the acid dissociable group of the polymer in the radiation-sensitive resin composition for immersion exposure can be smoothly advanced. As PEB temperature, 30 degreeC or more and 200 degrees C or less are preferable, and 50 degreeC or more and 150 degrees C or less are more preferable. If it is less than 30 degreeC of PEB temperature, the said dissociation reaction may not progress smoothly. When PEB temperature exceeds 200 degreeC, the acid generate | occur | produces from an [B] acid generator may diffuse to an unexposed part, and a favorable pattern may be hard to be obtained.

[Developing process]

In this step, the resist film immersed and exposed in the exposure step is developed. As a developing solution, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-dia Alkali aqueous solution which melt | dissolved at least 1 sort (s) of alkaline compounds, such as zacyclocyclo- [4.3.0] -5-nonene, is preferable. As a density | concentration of this aqueous alkali solution, 10 mass% or less is preferable.

As the developing method, for example, a method of immersing a substrate in a bath filled with a developer for a predetermined time (the dipping method), a method of raising the developer by raising the surface of the substrate by surface tension and stopping for a certain time (puddle method), a substrate A method of spraying a developer onto a surface (spray method), a method of continuously deriving a developer while scanning a developer extracting nozzle at a constant speed on a substrate rotated at a constant speed, and the like (dynamic dispensing method).

It is preferable to rinse with a rinse liquid after the said image development. As this rinse liquid, water is preferable. When the above-mentioned radiation-sensitive resin composition for immersion exposure is used, since the receding contact angle after development becomes smaller, the developer and the rinse solution can be in good contact with the surface of the resist film, and as a result, the occurrence of development defects is effectively suppressed.

<Example>

Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples. The measuring method of various physical property values is shown below.

[ ¹ H-NMR analysis and ¹³ C-NMR analysis]

¹ H-NMR analysis and ¹³ C-NMR analysis were carried out using a nuclear magnetic resonance apparatus (JNM-ECX400, manufactured by Nippon Denshi), and using tetramethylsilane (TMS) as an internal standard using CDCl ₃ as a measurement solvent. It was.

[Mw and Mn measurement]

Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) under the following conditions.

GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (made of plastic)

Elution solvent: tetrahydrofuran

Flow rate: 1.0 mL / min

Column temperature: 40 ℃

Standard material: monodisperse polystyrene

Detector: parallax refractometer

Synthesis of Compound

Synthesis Example 1

In a 1 L three-necked reactor equipped with a dropping funnel and a condenser, 120.9 g of 1,1,1-trifluoro-2-trifluoromethyl-2,4-butanediol, 62.9 g of triethylamine and 200 mL of dichloromethane Was added and cooled to 0 ° C. in an ice bath. Subsequently, 100.0 g of 2- (bromomethyl) acrylate was dripped over 30 minutes. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours. Thereafter, the precipitate was removed by filtration, and 200 mL of 1N hydrochloric acid was added to the obtained filtrate to stop the reaction. The obtained organic layer was washed sequentially with water and brine. Then, the organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. Thereafter, purification was carried out by distillation under reduced pressure to synthesize 137.8 g (yield 82%) of the compound represented by the following general formula (S-1).

¹ H-NMR data is shown below.

¹ H-NMR (CDCl ₃ ) δ: 1.31 (t, 3H), 2.27-2.30 (m, 2H), 3.89-3.91 (m, 2H), 4.22-4.28 (m, 4H), 5.81 (s, 1H) , 6.37 (s, 1H)

Synthesis Example 2

In the synthesis example 1, it carried out similarly to the synthesis example 1 except having used 92.7 g of methyl 2- (bromomethyl) acrylates instead of 100.0g of 2- (bromomethyl) acrylates, and it is represented by following General formula (S-2) 124.1 g of the compound to be expressed were synthesized (yield 77%).

¹ H-NMR data is shown below.

¹ H-NMR (CDCl ₃ ) δ: 2.29-2.32 (m, 3H), 3.90-3.93 (m, 2H), 4.23-4.30 (m, 4H), 5.83 (s, 1H), 6.35 (s, 1H)

Synthesis Example 3

In a 1 L three-necked reactor equipped with a dropping funnel and a condenser, 23.6 g of 1,1,1,3,3,3-hexafluoroisopropyl methacrylic acid, N, N'-dibromo-N, 55.4 g of N'-1,2-ethylenebis (2,5-dimethylbenzenesulfonamide) and 24.2 g of dibenzoylperoxide were dissolved in 1,000 mL of tetrachloroethane and stirred at room temperature for 1 hour. Thereafter, 1,000 mL of water was added to the reaction solution to stop the reaction. The obtained organic layer was washed with saturated brine. Then, the organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain 22.0 g of a precursor (yield 70%). Subsequently, 14.8 g of 1,1,1-trifluoro-2-trifluoromethyl-2,4-butanediol, 7.1 g of triethylamine, and dichloro were dried in a 1 L three-necked reactor equipped with a dropping funnel and a condenser. 200 mL of methane was added and cooled to 0 ° C. in an ice bath. Then, 22.0 g of the synthesized precursor was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours. Thereafter, the precipitate was removed by filtration, and 200 mL of 1N hydrochloric acid was added to the obtained filtrate to stop the reaction. The obtained organic layer was washed sequentially with water and brine. Subsequently, the organic layer was dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and then purified by distillation under reduced pressure to synthesize 25.0 g (yield 80%) of the compound represented by the following general formula (S-3).

¹ H-NMR data is shown below.

¹ H-NMR (CDCl ₃ ) δ: 3.85 (S, 1H), 3.90-3.93 (m, 2H), 4.23-4.30 (m, 4H), 5.83 (s, 1H), 6.35 (s, 1H)

Synthesis Example 4

1,1,1-trifluoro-2-trifluoromethyl-2 in place of 120.9 g of 1,1,1-trifluoro-2-trifluoromethyl-2,4-butanediol in Synthesis Example 1 Except for using 128.9 g of, 4-pentanediol, the same procedure as in Synthesis Example 1 was performed to synthesize 20.6 g of the compound represented by the following formula (S-4) (yield 75%).

¹ H-NMR data is shown below.

¹ H-NMR (CDCl ₃ ) δ: 1.31 (t, 3H), 1.50 (t, 3H), 2.27-2.30 (m, 2H), 3.54 (q, 1H), 3.89-3.91 (m, 2H), 4.22 -4.28 (m, 2H), 5.81 (s, 1H), 6.37 (s, 1H)

Synthesis Example 5

16.8 g of cyclohexyl methacrylate, 1,1,1-trifluoro-2- instead of 23.6 g of methacrylic acid 1,1,1,3,3,3-hexafluoroisopropyl in Synthesis Example 3 The same procedure as in Synthesis Example 3 was repeated except that 15.8 g of 1,1,1-trifluoro-2-trifluoromethyl-2,4-pentanediol was used instead of 14.8 g of trifluoromethyl-2,4-butanediol. , 27.4 g of compounds represented by the following formula (S-5) were synthesized (yield 70%).

¹ H-NMR data is shown below.

¹ H-NMR (CDCl ₃ ) δ: 1.21-1.56 (m, 10H), 2.27-2.30 (m, 2H), 3.89-3.91 (m, 2H), 4.12-4.20 (m, 1H), 4.22-4.28 ( m, 4H), 5.81 (s, 1H), 6.37 (s, 1H)

<Synthesis of polymer [A]>

The monomer used for the synthesis | combination of [A] polymer is shown below.

Synthesis Example 6 (Synthesis of Polymer (A-1))

8.77 g (80 mol%) of the compound (S-1) and 1.23 g (20 mol%) of the compound (M-2) were dissolved in 10 g of 2-butanone, and 0.42 g of AIBN was further dissolved to prepare a monomer solution. It was. Subsequently, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, heated to 80 ° C while stirring, and the prepared monomer solution was added dropwise over 3 hours with a dropping funnel. The dropping start was regarded as the start time of the polymerization reaction, and the polymerization reaction was performed for 6 hours. After completion | finish of a polymerization reaction, the polymerization reaction solution was cooled by water and cooled to 30 degrees C or less. The polymerization reaction solution cooled in 200 g of methanol was thrown in, and the precipitated white powder was separated by filtration. The white powder separated by filtration was washed twice with 40 g of methanol, then filtered and dried at 50 ° C. for 17 hours to synthesize white powdery polymer (A-1) (6.2 g, yield 62%). Mw of the polymer (A-1) was 4,500 and Mw / Mn was 1.43. ^As a result of ¹³ C-NMR analysis, the content ratio of the structural unit derived from (S-1) and the structural unit derived from (M-2) was 77.9 mol% and 22.1 mol%, respectively.

Synthesis Examples 7 to 13 (Synthesis of Polymers (A-2) to (A-6) and (CA-1) and (CA-2))

Each polymer was synthesize | combined similarly to the synthesis example 6 except having used the kind and quantity of the compound shown in Table 1. Table 1 shows the content ratios, Mw and Mw / Mn of each structural unit in the synthesized polymer.

<Synthesis of polymer [C]>

Synthesis Example 14

43.1 g (50 mol%) of the compound (M-1) and 56.9 g (50 mol%) of the compound (M-6) were dissolved in 100 g of 2-butanone, and 4.21 g of AIBN was further dissolved to prepare a monomer solution. It was. Subsequently, a 1,000 mL three-necked flask containing 200 g of 2-butanone was purged with nitrogen for 30 minutes, then heated to 80 ° C while stirring, and the monomer solution prepared above was added dropwise with a dropping funnel over 3 hours. The dropping start was regarded as the start time of the polymerization reaction, and the polymerization reaction was performed for 6 hours. After completion | finish of a polymerization reaction, the polymerization reaction solution was cooled by water and cooled to 30 degrees C or less. The polymerization reaction solution cooled in 2,000 g of methanol was thrown in, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol, filtered and dried at 50 ° C. for 17 hours to synthesize white powdery polymer (C-1) (62.3 g, yield 62%). Mw of the polymer (C-1) was 5,500, and Mw / Mn was 1.41. ^As a result of ¹³ C-NMR analysis, the content ratios of the structural unit derived from (M-1) and the structural unit derived from (M-6) were 48.2 mol% and 51.8 mol%, respectively.

Synthesis Examples 15 and 16

Each polymer was synthesize | combined similarly to the synthesis example 14 except having used the kind and amount of the compound shown in Table 2. The content rate, Mw, and Mw / Mn of each structural unit of the synthesized polymer are shown together in Table 2.

<Production of radiation sensitive resin composition for immersion exposure>

Each component used for manufacture of the radiation sensitive resin composition for liquid immersion exposure is shown below.

[[B] acid generator]

B-1: triphenylsulfonium nonafluoro-n-butanesulfonate (compound represented by the following formula (B-1))

[[D] Acid Diffusion Control Agents]

D-1: N-t-amyloxycarbonyl-4-hydroxypiperidine (compound represented by the following formula (D-1))

[[E] solvent]

E-1: Propylene Glycol Monomethyl Ether

E-2: cyclohexanone

E-3: γ-butyrolactone

Example 1 Preparation of Radiation Sensitive Resin Composition (J-1) for Liquid Immersion Exposure

[A] 5 parts by mass of (A-1) as polymer, [C] 100 parts by mass of (C-1) as polymer, [9.9] parts of (B-1) as acid generator, [D] acid diffusing agent 7.9 parts by mass of (D-1) as yesterday and 2,590 parts by mass of (E-1), 1,110 parts by mass of (E-2) and 200 parts by mass of (E-3) as solvents for [E]. Filtration was carried out with the filter of micrometers, and the radiation sensitive resin composition (J-1) for liquid immersion exposure was produced.

[Examples 2 to 8 and Comparative Examples 1 and 2] (Preparation of the radiation sensitive resin compositions (J-2) to (J-8) and (CJ-1) and (CJ-2) for immersion exposure)

Except having used each component of the kind and compounding quantity shown in Table 3, it operated like Example 1, and produced the radiation sensitive resin composition for each immersion exposure.

<Evaluation>

The resist film was formed on the board | substrate using each produced radiation sensitive resin composition for immersion exposure. The substrate was an 8-inch silicon wafer when measuring the receding contact angle, and a 12-inch silicon wafer where an underlayer antireflection film (ARC66, manufactured by Nissan Chemical Co., Ltd.) was formed when measuring the number of developing defects. The following evaluation was performed about each formed resist film. The evaluation results are shown in Table 3 together.

[Retraction contact angle]

With respect to the formed resist film, the receding contact angle was measured in the following order using a contact angle meter (DSA-10, manufactured by KRUS) under an environment of room temperature 23 ° C., humidity 45%, and normal pressure.

The needle of DSA-10 is washed with acetone and isopropyl alcohol before measurement, water is subsequently poured into the needle, and a wafer on which a resist film is formed on the wafer stage is set. The height of the stage is adjusted so that the tip distance between the surface of the resist film and the needle is 1 mm or less, and then water is discharged from the needle to form 25 μL of water droplets on the resist film, and then the water droplet is discharged by the needle at a speed of 10 μL / min. The contact angle was measured every second while sucking for 180 seconds. Since the contact angle was stabilized, the average value was computed about the contact angle of 20 points in total, and it was set as the receding contact angle (degree).

(Retraction contact angle after SB)

After apply | coating each radiation sensitive resin composition for immersion exposure on an 8-inch silicon wafer, SB was performed at 100 degreeC for 60 second, and the resist film of a film thickness of 110 nm was formed. The receding contact angle on the resist film surface was referred to as "retreating contact angle after SB".

(Retreat contact angle after development)

After apply | coating each radiation sensitive resin composition for immersion exposure on an 8-inch silicon wafer, SB was performed at 100 degreeC for 60 second, and the resist film of a film thickness of 110 nm was formed. Subsequently, after developing for 30 second by 2.38 mass% tetramethylammonium hydroxide aqueous solution with the GP nozzle of the developing apparatus (Clean Track ACT8, Tokyo Electron make), and rinsing with pure water for 15 second, it was 2,000, The receding contact angle on the surface of the resist film after liquid-drying at rpm was set to "retreating contact angle after development".

[Defective defects]

After applying the radiation-sensitive resin composition for liquid immersion exposure on the 12-inch silicon wafer on which the lower layer antireflection film (ARC66, manufactured by Nissan Chemical Industries, Ltd.) was formed, SB was performed at 100 ° C. for 60 seconds to form a resist film having a thickness of 110 nm. It was. Subsequently, the resist film was formed using an ArF excimer laser immersion exposure apparatus (NSR S610C, manufactured by Nikon) under a condition of NA = 1.3, ratio = 0.812, and Crosspole, for line and space formation having a line width of 55 nm. It exposed through the pattern. After exposure, PEB was performed at 120 ° C. for 60 seconds. Then, it developed by 2.38 mass% tetramethylammonium hydroxide aqueous solution, and it washed with water and dried, and formed the positive resist pattern. At this time, the exposure amount which forms the line and space of width 55nm was made into the optimal exposure amount. At this optimum exposure amount, a line and space having a line width of 55 nm was formed on the entire wafer surface to form a wafer for developing defect inspection. In addition, the scanning electron microscope (S-9380, Hitachi High-Technologies Corporation) was used for side length measurement of a resist pattern. The number of developing defects on the obtained developing defect inspection wafer was measured using a defect inspection apparatus (KLA2810, manufactured by KLA-Tencor). The measured defect was classified into the thing judged that it originated from a resist, and the foreign material of external origin. After the classification, the number of those judged to be derived from the resist was summed up to "development defect number". The numerical value of the image development defect number is shown in Table 3. The development defect suppression property of the radiation-sensitive resin composition for immersion exposure can be determined to be "good" when the number of developing defects is less than 50 / wafer, and "bad" when it is 50 / wafer or more.

As apparent from the results of Table 3, when the radiation-sensitive resin composition for immersion exposure of the example was used, it was confirmed that the receding contact angle was larger after SB and significantly decreased after development, compared with that of the comparative example. It was found that the receding contact angle change at the time of immersion exposure and after development was excellent. Moreover, according to the radiation sensitive resin composition for liquid immersion exposure of the Example, it turned out that image development defect is very hard to generate | occur | produce.

According to the radiation-sensitive resin composition for a liquid immersion exposure and the method of forming a resist pattern of the present invention, a resist pattern with few development defects can be formed while increasing the speed of scan exposure. Therefore, this invention can be used suitably for a liquid immersion exposure process, and can improve the productivity and the quality of the resist pattern formed.

Claims (6)

[A] a polymer having a structural unit represented by the following formula (1),
[B] a radiation sensitive acid generator, and
[C] A polymer having a lower content of fluorine atoms than a polymer [A]
Containing,
The radiation sensitive resin composition for liquid immersion exposure in which this [C] polymer has an acid dissociable group.

(In formula (1), R <^1> is a hydrogen atom or a C1-C20 monovalent organic group, R <^2> is a single bond, a C1-C20 bivalent linear hydrocarbon group, a C3-C20 bivalent alicyclic type It is a hydrocarbon group or group which combined 1 or 2 or more types, and -O-, R <^3> is a hydrogen atom or a C1-C20 monovalent organic group, R ^<A> is a hydrogen atom or a C1-C20 Monovalent organic group) The radiation sensitive resin composition for liquid immersion exposure according to claim 1, wherein the polymer (A) further has a structural unit containing an acid dissociable group. The radiation sensitive resin composition for liquid immersion exposure of Claim 1 which further contains the [D] acid diffusion control body. [A] a polymer having a structural unit represented by the following formula (1),
[B] a radiation sensitive acid generator, and
[C] A polymer having a lower content of fluorine atoms than a polymer [A]
Containing,
A radiation sensitive resin composition in which this [C] polymer has an acid dissociable group.

(In formula (1), R <^1> is a hydrogen atom or a C1-C20 monovalent organic group, R <^2> is a single bond, a C1-C20 bivalent linear hydrocarbon group, a C3-C20 bivalent alicyclic type It is a hydrocarbon group or the group which combined 1 or 2 or more types of these, and -O-, R <^3> is a hydrogen atom or a C1-C20 monovalent organic group, R ^<A> is a hydrogen atom or C1-C20 Monovalent organic group) Forming a resist film from the radiation sensitive resin composition for liquid immersion exposure according to claim 1,
Immersing the resist film through a liquid for liquid immersion exposure, and
Developing the immersion-exposed resist film
Resist pattern forming method having a. delete