JP4524207B2 - Positive resist composition for immersion exposure and pattern forming method using the same - Google Patents

Description

  The present invention relates to a photoresist used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and a lithography process for other photo applications. In particular, the present invention relates to a photoresist composition suitable for exposure with an immersion projection exposure apparatus using far ultraviolet light having a wavelength of 220 nm or less as a light source, and a method for forming the resist pattern.

Along with the miniaturization of semiconductor elements, the exposure light source has become shorter in wavelength and the projection lens has a higher numerical aperture (high NA). Currently, an NA0.84 exposure machine using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed. Has been. These can be expressed by the following equations as is generally well known.
(Resolving power) = k ₁ · (λ / NA)
(Depth of focus) = ± k ₂ · λ / NA ²
Here, λ is the wavelength of the exposure light source, NA is the numerical aperture of the projection lens, and k ₁ and k ₂ are coefficients related to the process.
An exposure machine using a F ₂ excimer laser having a wavelength of 157 nm as a light source has been studied for higher resolution by further shortening the wavelength. Lens materials and photo used for the exposure apparatus for shorter wavelength have been studied. Since the materials used for resist are very limited, it is very difficult to stabilize the manufacturing cost and quality of the equipment and materials, and exposure equipment and photoresist that have sufficient performance and stability for the required period are in time. The view that there is no is growing.

As a technique for increasing the resolving power in an optical microscope, a so-called immersion method in which a high refractive index liquid (hereinafter also referred to as “immersion liquid”) is filled between an objective lens and a sample is conventionally known.
This “immersion effect” means that when λ ₀ is the wavelength of the exposure light in the air, n is the refractive index of the immersion liquid with respect to air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. The above-described resolving power and depth of focus can be expressed by the following equations.
(Resolving power) = k ₁ · (λ ₀ / n) / NA ₀
(Depth of focus) = ± k ₂ · (λ ₀ / n) / NA ₀ ²
That is, the immersion effect is equivalent to using an exposure wavelength having a wavelength of 1 / n. In other words, in the case of the projection optical system having the same NA, the depth of focus can be increased n times by immersion. This is effective for all pattern shapes, and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method which are currently being studied.

  When using an ArF excimer laser as the light source, pure water (refractive index at 193 nm: 1.44) is the most promising immersion liquid for immersion exposure in terms of handling safety and transmittance and refractive index at 193 nm. It is considered to be. When using an F2 excimer laser as a light source, a solution containing fluorine has been studied from the balance of transmittance and refractive index at 157 nm, but a sufficient product has not yet been found in terms of environmental safety and refractive index. It has not been. Based on the degree of immersion effect and the degree of perfection of resist, immersion exposure technology is considered to be installed on ArF exposure machines the earliest.

  As described above, application of the immersion exposure method is expected to bring great advantages to the semiconductor industry in terms of cost and lithography characteristics such as resolution. On the other hand, in the case of immersion exposure, the resist film comes into direct contact with the immersion liquid at the time of exposure. Therefore, in the case of ArF immersion, the resist film components are eluted into the pure water that is the immersion liquid and contaminates the exposure unit lens. In addition, there is a concern that pure water permeates the resist film and adversely affects the resist performance.

  In order to solve the problems caused by the interaction between the resist film and water as described above, it is effective to reduce the affinity between the resist film and water. On the other hand, reducing the affinity between the resist film and water tends to lead to a loss of the affinity between the resist film and the alkaline developer at the same time, resulting in an increase in the number of development defects in the resist. It was easy to connect.

Patent Document 1 (International Publication No. 2004-068242A1 pamphlet) describes a resist composition that does not impair the improvement in resolution and depth of focus, which are the advantages of immersion lithography, and is less susceptible to the adverse effects of water used in the immersion lithography process. Has been. On the other hand, the resist composition described in this document has room for improvement in terms of dissolution of resist film components into water, development defects, and resolution.
International Publication No. 2004-068242A1 Pamphlet

  The object of the present invention is to solve the problems of the conventional immersion exposure technology as described above, and the amount of acid elution into water is extremely small, the number of development defects is reduced, and the resolution during immersion exposure is further reduced. An object of the present invention is to provide an improved resist suitable for immersion exposure.

  The present invention is a positive resist composition for immersion exposure having the following constitution, whereby the above object of the present invention is achieved.

一般式（ＩＩ）において、
Ｒ_f1及びＲ_f2は、それぞれ独立に、水素原子、アルキル基又はフルオロアルキル基を表す。但し、Ｒ_f1及びＲ_f2のうち少なくとも１つは、フルオロアルキル基である。

一般式（ＡIIａ）中、
Ｒ_1cは、水素原子、メチル基、トリフロロメチル基又はヒドロキシメチル基を表す。
Ｒ_2c〜Ｒ_4cは、各々独立に、水素原子、水酸基又はシアノ基を表す。ただし、Ｒ_2c〜Ｒ_4cのうち少なくとも１つは、水酸基を表す。
（２） 純水に対する静的接触角が７４°以上であり、２．３８％テトラメチルアンモニウムヒドロキシド水溶液に対する静的接触角が６９°以下であることを特徴とする上記（１）に記載の液浸露光用ポジ型レジスト組成物。
（３） 純水に対する静的接触角が７６°以上であり、２．３８％テトラメチルアンモニウムヒドロキシド水溶液に対する静的接触角が６８°以下であることを特徴とする上記（１）に記載の液浸露光用ポジ型レジスト組成物。
（４） （Ａ）成分の樹脂が、更に、下記一般式（ＰＡ）で表される繰り返し単位を有することを特徴とする上記（１）〜（３）のいずれかに記載の液浸露光用ポジ型レジスト組成物。

ここで、
Ｒは、水素原子、ハロゲン原子又は１〜４個の炭素原子を有する直鎖もしくは分岐のアルキル基を表す。複数のＲは、各々同じでも異なっていてもよい。
Ａは、単結合、アルキレン基、エーテル基、チオエーテル基、カルボニル基、エステル基、アミド基、スルホンアミド基、ウレタン基、又はウレア基よりなる群から選択される単独あるいは２つ以上の基の組み合わせを表す。
Ｒｐ１は、下記一般式（ｐI）〜（ｐＶ）のいずれかの基を表す。

一般式（ｐI）〜（ｐＶ）中、
Ｒ₁₁は、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基又はｓｅｃ−ブチル基を表し、Ｚは、炭素原子とともにシクロアルキル基を形成するのに必要な原子団を表す。
Ｒ₁₂〜Ｒ ₁₄ は、各々独立に、炭素数１〜４個の、直鎖もしくは分岐のアルキル基又はシクロアルキル基を表す。但し、Ｒ₁₂〜Ｒ₁₄のうち少なくとも１つは、シクロアルキル基を表す。
Ｒ ₁₅ 、Ｒ ₁₆ は、各々独立に、炭素数１〜４個の、直鎖もしくは分岐のアルキル基又はシクロアルキル基を表す。但し、Ｒ ₁₅ 、Ｒ ₁₆ の少なくともいずれかは、シクロアルキル基を表す。
Ｒ₁₇〜Ｒ₂₁は、各々独立に、水素原子、炭素数１〜４個の、直鎖もしくは分岐のアルキル基又はシクロアルキル基を表す。但し、Ｒ₁₇〜Ｒ₂₁のうち少なくとも１つは、シクロアルキル基を表す。また、Ｒ₁₉、Ｒ₂₁のいずれかは、炭素数１〜４個の、直鎖もしくは分岐のアルキル基又はシクロアルキル基を表す。
Ｒ₂₂〜Ｒ₂₅は、各々独立に、水素原子、炭素数１〜４個の、直鎖もしくは分岐のアルキル基又はシクロアルキル基を表す。但し、Ｒ₂₂〜Ｒ₂₅のうち少なくとも１つは、シクロアルキル基を表す。また、Ｒ₂₃とＲ₂₄は、互いに結合して環を形成していてもよい。
（５） （Ａ）成分の樹脂が、更に、下記一般式（ＡＩ）で表される繰り返し単位を有することを特徴とする上記（１）〜（４）のいずれかに記載の液浸露光用ポジ型レジスト組成物。

一般式（ＡＩ）中、
Ｒ_b0は、水素原子、ハロゲン原子、又は炭素数１〜４のアルキル基を表す。
Ａｂは、単結合、アルキレン基、単環若しくは多環の脂環炭化水素構造を有する２価の連結基、エーテル基、エステル基、カルボニル基、又はこれらを組み合わせた２価の基を表す。
Ｖは、下記一般式（ＬＣ１−１）〜（ＬＣ１−１６）のうちのいずれかで示される基を表す。

式中、
Ｒｂ₂は、置換基を表す。
ｎ₂は、０〜３の整数を表す。
（６） （Ａ）成分の樹脂における一般式（ＩＩ）で示される基を有する繰り返し単位の含有割合が５〜３０モル％であることを特徴とする上記（１）〜（５）のいずれかに記載の液浸露光用ポジ型レジスト組成物。
（７） 上記（１）〜（６）のいずれかに記載のレジスト組成物によりレジスト膜を形成し、該レジスト膜を液浸露光し、現像する工程を含むことを特徴とするパターン形成方法。 (1) (A) a resin having a repeating unit having a group represented by the following general formula (II) and a repeating unit represented by the general formula (AIIa), and having increased solubility in an alkali developer by the action of an acid; And (B) a compound that generates an acid upon irradiation with actinic rays or radiation, and has a static contact angle with respect to pure water of 72 ° or more when a coating film is formed on the substrate. A positive resist composition for immersion exposure, wherein the static contact angle with respect to an aqueous solution of 38% tetramethylammonium hydroxide is 70 ° or less (however, compound 5 which generates an acid upon irradiation with actinic rays or radiation) Excluding a positive photosensitive composition containing 20 parts by mass and 100 parts by mass of a resin having a fluorine atom and having a group that is decomposed by the action of an acid to increase the solubility in an alkaline developer. .

In general formula (II):
R _f1 and R _f2 each independently represent a hydrogen atom, an alkyl group or a fluoroalkyl group. However, at least one of R _f1 and R _f2 is a fluoroalkyl group.

In general formula (AIIa),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl -thieno group.
R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.
(2) The static contact angle with respect to pure water is 74 ° or more, and the static contact angle with respect to a 2.38% tetramethylammonium hydroxide aqueous solution is 69 ° or less. A positive resist composition for immersion exposure.
(3) The static contact angle with respect to pure water is 76 ° or more, and the static contact angle with respect to a 2.38% tetramethylammonium hydroxide aqueous solution is 68 ° or less. A positive resist composition for immersion exposure.
(4) The resin of component (A) further has a repeating unit represented by the following general formula (PA), for immersion exposure according to any one of (1) to (3) above Positive resist composition.

here,
R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents.
Rp1 represents one of the following general formulas (pI) to (pV).

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R ₁₂ to R ₁₄ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. Provided that at least one of R ₁₂ to R ₁₄ represents a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represent a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.
(5) The resin of component (A) further has a repeating unit represented by the following general formula (AI), for immersion exposure according to any one of (1) to (4) above Positive resist composition.

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.
V represents a group represented by any one of the following general formulas (LC1-1) to (LC1-16).

Where
Rb ₂ represents a substituent.
n ₂ represents an integer of 0 to 3.
(6) Any of (1) to (5) above, wherein the content of the repeating unit having a group represented by formula (II) in the resin of component (A) is 5 to 30 mol% A positive resist composition for immersion exposure as described in 1. above.
(7) A pattern forming method comprising a step of forming a resist film from the resist composition according to any one of (1) to (6), subjecting the resist film to immersion exposure, and developing.

  According to the present invention, there is provided a resist composition suitable for immersion exposure, which has excellent resolution at the time of immersion exposure, has reduced development defects, and has reduced dissolution of acid generated in water. Can be provided.

The present invention relates to the above (1) to (6), but other matters are also described for reference.
When the resist composition of the present invention is applied onto a substrate to form a dry film, the static contact angle with respect to pure water is 72 ° or more and the static contact angle with respect to an alkaline developer is 70 ° or less, preferably static. The static contact angle is 74 ° or more and the static contact angle to the alkaline developer is 69 ° or less, more preferably the static contact angle is 76 ° or more and the static contact angle to the alkaline developer is 68 ° or less. It is characterized by.

  When the liquid touches the solid surface, round droplets are formed as shown in FIG. At this time, an angle θ formed by the solid sample and the liquid droplet at the liquid contact portion is called a static contact angle.

  The contact angle is an important physical property representing the wettability between a solid and a liquid, and is also a measure of the wettability of the solid surface. That is, when the solid surface and the liquid are compatible, θ becomes an acute angle, and the liquid wets the solid surface. On the other hand, when the solid surface and the liquid are incompatible, θ becomes an obtuse angle, and the liquid is repelled from the solid surface.

  The resist composition of the present invention has a static contact angle with respect to pure water of 72 ° to 84 °, preferably 74 ° to 82 °, more preferably 76 ° to 80 ° when coated on a substrate to form a dry film. Therefore, since the resist film has little affinity for water and the resist film repels water, there is an effect of preventing elution of the resist film components. On the other hand, the resist composition of the present invention has a static contact angle with an alkali developer of 40 ° to 70 °, preferably 45 ° to 69 °, more preferably 50 when coated on a substrate to form a dry film. Since it has a high affinity with an alkali developer of from ˜68 °, it is easy to get wet with the alkali developer, so that the development reaction proceeds smoothly, the occurrence of development defects can be suppressed, and high resolution can be exhibited.

As a method for measuring the contact angle, the θ / 2 method is known. That is, the liquid deposited on the solid has a round shape due to its surface tension and forms a part of a sphere as shown in FIG. The shape at this time is photographed, and the radius (r) and height (h) of the droplet are obtained from the left and right end points and the vertex position of the droplet. It is possible to calculate the contact angle θ by substituting the obtained value into the following formula.
tan θ ₁ = h / r
If the droplet is a part of a sphere,
θ ₁ = θ / 2
At present, the shape of a droplet formed when a liquid is deposited on a solid surface is captured by a CCD camera or the like, and the droplet radius r and height h are automatically analyzed by image processing to obtain a static contact angle θ. An automatic contact angle measuring device for calculating the value is also commercially available.

  The pure water in the present specification is a level of pure water used in the immersion exposure process, and is ultrapure water having an electrical resistance of 18.2 MΩ at 25 ° C. The alkaline developer in the present specification is not particularly limited as long as it is an alkaline aqueous solution used in a semiconductor manufacturing process, but is usually a 2.38% tetramethylammonium hydroxide aqueous solution.

  On the other hand, when the liquid and the solid surface are dynamic with respect to the static contact angle described above, the angle formed by the solid surface and the liquid droplet is called a dynamic contact angle. There are two types of dynamic contact angles, called advancing contact angles and receding contact angles. For example, in the dynamic contact angle measurement method called the falling method shown in FIG. 3, when a droplet falls by tilting a solid sample, it is formed at the interface between the droplet and the solid surface in front of the falling direction of the droplet. The advancing contact angle is the advancing contact angle, and the contact angle formed at the interface between the droplet and the solid surface behind the dropping direction of the droplet is the advancing contact angle.

  In the immersion exposure process, since the scan exposure is performed at high speed with water sandwiched between the lens and the resist film, it is important that the water sandwiched between the lens and the resist film follows the wafer scan. With respect to the water followability, the dynamic contact angle on the resist film is important, and the receding contact angle of water is preferably an obtuse angle. The resist composition of the present invention also desirably has a high receding contact angle, preferably 30 ° or more, more preferably 50 ° or more.

  In the resist composition of the present invention, a preferable constituent material is appropriately selected in order to design the static contact angle in the preferable range described above. Hereinafter, the compounds used in the present invention will be described in detail.

(A) Resin whose solubility in an alkaline developer is increased by the action of an acid
In the present invention, the resin whose solubility in an alkaline developer is increased by the action of an acid has a repeating unit having a group represented by the general formula (II) and a repeating unit represented by the general formula (AIIa). Resins whose solubility in an alkaline developer is increased by the action of other acids are also described for reference.
The resist composition of the present invention contains a resin (acid-decomposable resin) whose solubility in an alkaline developer is increased by the action of an acid. The acid-decomposable resin is a group capable of decomposing under the action of an acid into an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”) on the main chain or side chain of the resin, or both of the main chain and side chain It is resin which has.
Examples of the alkali-soluble group include a carboxyl group, a hydroxyl group, and a sulfonic acid group.
A preferred group that can be decomposed with an acid is a group in which the hydrogen atom of the —COOH group is substituted with a group capable of leaving with an acid.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The resist composition of the present invention is a repeating unit having groups represented by the following general formulas (I) to (V) in order to adjust the static contact angle with water and the static contact angle with an alkali developer during film formation. It is preferable to have at least one kind. The following general formula (I) is a carboxylic acid group adjacent to a hydrophobic hydrocarbon ring, and (II) to (V) are pKa7 to 11 weakly acidic groups. For this reason, while being in contact with pure water, it is hydrophobic and has an effect of increasing the static contact angle of the resist film with water. On the other hand, when in contact with an alkali developer, the acid group is dissociated by the action of alkali and the resist film becomes hydrophilic. The effect of lowering the static contact angle of the resist film with respect to the alkaline developer is exhibited.

In the above general formula:
Z represents a divalent organic group having a ring structure.
L represents a single bond or an alkylene group.
R _f1 and R _f2 each independently represent a hydrogen atom, an alkyl group, or a fluoroalkyl group. However, at least one of R _f1 and R _f2 is a fluoroalkyl group.
R ₁ represents a hydrogen atom, a halogen atom, a nitro group, an acyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an aralkyl group, or an aryl group.
R ₂ represents — (C═O) —R ₃ , a nitrile group.
R ₃ represents a hydrogen atom, an alkyl group, a cycloalkyl group, a fluoroalkyl group, an alkoxy group, an aralkyl group, or an aryl group.
R ₁ and R ₃ may be bonded to each other to form a ring structure.
R _a represents a hydrogen atom or a halogen atom.
n represents an integer of 0 to 4.

The divalent organic group having a ring structure of Z in the above general formula is preferably a monocyclic / polycyclic hydrocarbon residue having 3 to 20 carbon atoms, such as a cyclopropyl residue or a cyclobutyl residue. , Cyclopentyl residue, cyclohexyl residue, norbornane residue, adamantyl residue, tricyclodecanyl residue, isobornyl residue, dinorbornane residue and the like.
As the alkylene group of L in the above general formula, those having 1 to 6 carbon atoms are preferable, and linear and branched ones are included. Preferable examples include a methylene group, an ethylene group, a propylene group, and an isopropylene group.

As the alkyl group of R _f1 and R _f2 in the above general formula, those having 1 to 6 carbon atoms are preferable, including linear and branched ones. Preferable examples include a methyl group, an ethyl group, a propyl group, and an isopropyl group.
As a fluoroalkyl group of _Rf1 and _Rf2 in the said general formula, a C1-C8 thing is preferable and a linear and branched thing is included. Preferable examples include trifluoromethyl group, difluoromethyl group, monofluoroethyl group, pentafluoroethyl group, perfluorobutyl group, perfluorooctyl group and the like.
R _f1 and R _f2 in the above general formula are preferably both trifluoromethyl groups.

Examples of the halogen atom for R ₁ in the above general formula include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom or a chlorine atom is preferable.
The acyl group for R ₁ is preferably one having 2 to 12 carbon atoms, and examples thereof include an acetyl group, a propionyl group, a butyryl group, and a benzoyl group.
As the alkyl group for R ₁ , an alkyl group having 1 to 20 carbon atoms is preferable. For example, a linear or branched chain alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, or a dodecyl group, A fluoroalkyl group in which at least one hydrogen atom of these alkyl groups is substituted with a fluorine atom, and the like are preferable.
The cycloalkyl group represented by R ₁ is preferably a cycloalkyl group having 3 to 20 carbon atoms, such as a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, an adamantyl group, a norbornyl group, or a tetracyclodecanyl group. Examples include polycyclic cycloalkyl groups.
As the alkoxy group for R _1, an alkoxy group having 1 to 20 carbon atoms is preferable, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an adamantoxy group, a norbornaneoxy group and a norborneneoxy group. it can.
The aralkyl group for R ₁ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.
As the aryl group for R _1, an aryl group having 6 to 10 carbon atoms is preferable. For example, phenyl group, tolyl group, dimethylphenyl group, 2,4,6-trimethylphenyl group, naphthyl group, anthryl group, 9, A 10-dimethoxyanthryl group can be exemplified.

Examples of the alkyl group for R ₃ include the same alkyl groups as R ₁ described above.
As the cycloalkyl group for R _3, the same cycloalkyl groups as those described above for R ₁ can be used.
Examples of the fluoroalkyl group for R ₃ include the same groups as those described above for R _f1 and R _f2 .
Examples of the alkoxy group for R ₃ include the same groups as those for R ₁ described above.
Examples of the aralkyl group for R ₃ include the same groups as those for R ₁ described above.
Examples of the aryl group for R ₃ include the same groups as those for R ₁ described above.
The ring that can be formed by combining R ₁ and R ₃ may be monocyclic or polycyclic, preferably having 5 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, such as cyclohexyl. Group, norbornane residue, isobornyl residue, adamantyl residue and the like.

  Specific preferred examples of the group represented by the general formula (I) are shown below, but the present invention is not limited thereto.

  Specific examples of preferred repeating units containing a group represented by formula (I) are shown below, but the present invention is not limited to these.

  Specific preferred examples of the group represented by the general formula (II) are shown below, but the present invention is not limited thereto.

  Specific examples of preferred repeating units containing a group represented by formula (II) are shown below, but the present invention is not limited to these.

  Specific preferred examples of the group represented by the general formula (III) are shown below, but the present invention is not limited thereto.

  Specific examples of preferred repeating units containing a group represented by formula (III) are shown below, but the present invention is not limited to these.

  Specific examples of preferred groups represented by general formula (IV) are shown below, but the present invention is not limited thereto.

  Specific examples of preferred repeating units having a group represented by formula (IV) are shown below, but the present invention is not limited thereto.

  Specific examples of preferred repeating units having a group (sulfonamide) represented by the formula (V) are shown below, but the present invention is not limited to these.

  Resin containing the repeating unit which has group represented by general formula (I)-(V) can synthesize | combine the monomer marketed by a normal method.

  The content of the repeating units having the groups represented by the general formulas (I) to (V) in the resin (A) is preferably 5 mol% to 30 mol% in total, more preferably 7 mol%. -25 mol%, most preferably 10 mol% to 20 mol%.

  The resin (A) contained in the positive resist composition of the present invention is optional in addition to the repeating unit having a group represented by the general formula (A) in the side chain and the repeating unit represented by the general formula (B). The repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV), and the following general formula (II-AB) A resin containing at least one selected from the group of repeating units is preferred.

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or R ₁₅ , Any of R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group, provided that at least one of R _{17 to} R ₂₁ is cyclo Represents an alkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group, provided that at least one of R _{22 to} R ₂₅ is cyclo Represents an alkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the formula (II-AB),
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group. Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

  The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In the formula (II-AB1) (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cycloalkyl group.
Wherein, R ₅ represents an alkyl group, a cycloalkyl group or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring. n represents 0 or 1.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.

In the general formulas (pI) to (pV), the alkyl group in R _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms.

The cycloalkyl group in R _{11 to} R ₂₅ or the cycloalkyl group formed by Z and the carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These cycloalkyl groups may have a substituent.

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

  As further substituents of these alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers) 2-6). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pV) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a structure in which a hydrogen atom of a carboxylic acid group, a sulfonic acid group, a phenol group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (PV), preferably a carboxylic acid Group, the hydrogen atom of a sulfonic acid group is the structure substituted by the structure represented by general formula (pI)-(PV).

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pV), a repeating unit represented by the following general formula (pA) is preferable.

Here, R represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. A single bond is preferable.
Rp1 represents any group of the above formulas (pI) to (pV).

  The repeating unit represented by the general formula (pA) is most preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

Specific examples of the repeating unit represented by the general formula (pA) are shown below. In specific examples, Rx represents H, CH ₃ , CH ₂ OH or CF ₃ . Rxa and Rxb each independently represents an alkyl group having 1 to 4 carbon atoms.

The R ₁₁ ', R _12' As the halogen atom in include a chlorine atom, a bromine atom, a fluorine atom, an iodine atom.

Examples of the alkyl group for R ₁₁ ′ and R ₁₂ ′ include linear or branched alkyl groups having 1 to 10 carbon atoms.

  The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{25 in} the general formulas (pI) to (pVI).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

  In the resin (A) according to the present invention, the group (acid-decomposable group) that is decomposed by the action of an acid includes a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). Among the repeating units represented by formula (II-AB), and the repeating units of the copolymerization component described later.

The various substituents R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) are atomic groups for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

  The resin (A) of the present invention preferably has a lactone group. As the lactone group, any group can be used as long as it contains a lactone structure, but preferably a group containing a 5- to 7-membered ring lactone structure, and a bicyclo structure in the 5- to 7-membered ring lactone structure, Those in which other ring structures are condensed to form a spiro structure are preferred. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-15). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1) (LC1-4) (LC1-5) (LC1-6) (LC1-13) (LC1-14). By using a specific lactone structure, line edge roughness, Development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. When n ₂ is 2 or more, a plurality of Rb ₂ may be the same or different, and a plurality of Rb ₂ may be bonded to form a ring.

As the repeating unit having a group having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-13), R _{13 in the} general formula (II-AB1) or (II-AB2) is used. Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16) or a repeating unit represented by the following general formula (AI).

In general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group for R _b0 may have include a hydroxyl group and a halogen atom.

Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom or a methyl group.

A _b is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. Represents. Preferably a single bond, -Ab ₁ -CO ₂ - is a linking group represented by.
Ab1 is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.

  V represents a group represented by any one of the general formulas (LC1-1) to (LC1-16).

The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.
Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto. In specific examples, Rx represents H, CH ₃ , CH ₂ OH or CF ₃ .

  The resin (A) of the present invention preferably contains a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The polar group is preferably a hydroxyl group or a cyano group. Examples of the alicyclic hydrocarbon structure substituted with a polar group include the following.

In general formula (VIIa), R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the remaining is a hydrogen atom, more preferably two of R _{2c to} R _4c are a hydroxyl group and the remaining is a hydrogen atom.

  The group represented by the general formula (VII) is preferably a dihydroxy body or a monohydroxy body, and more preferably a dihydroxy body.

As the repeating unit having a group represented by the general formula (VIIa) or (VIIb), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2) is the above. Those having a group represented by the general formula (VII) (for example, R _{5 of} —COOR ₅ represents a group represented by the general formula (VII)), or the following general formulas (AIIa) and (AIIb) The repeating unit represented, etc. can be mentioned.

In general formulas (AIIa) and (AIIb), R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

  Specific examples of the repeating unit having a structure represented by the general formulas (AIIa) and (AIIb) are given below, but the present invention is not limited thereto.

  The resin (A) of the present invention may contain a repeating unit represented by the following general formula (VIII).

In the general formula (VIII), Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

  The resin (A) of the present invention may have a repeating unit having an alkali-soluble group or may have a repeating unit having a carboxyl group. Inclusion of this tends to increase the resolution in contact hole applications. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Any of the bonded repeating units is preferable, and the linking group may have a monocyclic or polycyclic hydrocarbon structure. Most preferred are acrylic acid and methacrylic acid.

  The resin (A) of the present invention has, in addition to the above repeating structural units, dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required characteristics of resist, resolving power, heat resistance, sensitivity. Various repeating structural units can be contained for the purpose of adjusting the above.

  Examples of such a repeating structural unit include, but are not limited to, repeating structural units corresponding to the following monomers.

  As a result, the performance required for the resin (A), in particular, (1) solubility in coating solvents, (2) film-forming properties (glass transition point), (3) alkali developability, (4) film slipping (familiarity) Fine adjustments such as (selection of aqueous and alkali-soluble groups), (5) adhesion of unexposed portions to the substrate, and (6) dry etching resistance are possible.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In the resin (A), the molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and the general required performance of the resist, resolving power, heat resistance, sensitivity. It is set appropriately in order to adjust etc.

The following are mentioned as a preferable aspect of resin (A) of this invention.
(1) What contains the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by the said general formula (pI)-(pV) (side chain type). Preferably those containing (meth) acrylate repeating units having a structure of (pI) to (pV).
(2) A repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type)
In the resin (A), the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol% in all repeating structural units. is there.

  In the resin (A), the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is preferably 25 to 70 mol% in all repeating structural units, More preferably, it is 35-65 mol%, More preferably, it is 40-60 mol%.

  In the resin (A), the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 in all repeating structural units. ˜50 mol%.

  In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. ) To 99 p% with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon represented by (pV) and the repeating unit represented by the general formula (II-AB). The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.
The resin (A) used in the present invention is preferably one in which all of the repeating units are composed of acrylate derivatives such as methacrylate, acrylate, and α-substituted acrylate. In this case, all of the repeating units can be methacrylates, all of the repeating units can be acrylates, all of the repeating units can be α-substituted acrylates, or methacrylate / acrylate / α-substituted acrylate mixtures. Is preferably 50 mol% or less of all repeating units. More preferably 3 to 30% of repeating units containing a group represented by formula (A) in the side chain and a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by formulas (pI) to (pV) 25 to 50%, quaternary copolymer containing 5 to 30% of repeating units having an alicyclic hydrocarbon structure substituted with the polar group, or 25 to 50% of repeating units containing the lactone structure, or a carboxyl group Or it is a 5-component copolymer containing 5 to 20% of repeating units containing the structure represented by the general formula (F1).

The resin (A) used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50 to 100 ° C.

  In the positive resist composition of the present invention, the blending amount of all the resins (A) according to the present invention in the entire composition is preferably 40 to 99.99% by mass, more preferably 50 to 50% in the total resist solid content. It is 99.97 mass%.

(B) Compound that generates acid upon irradiation with actinic ray or radiation Compound that generates acid upon irradiation with actinic ray or radiation (hereinafter referred to as “acid generator”) used in the resist composition for immersion exposure of the present invention Will be described below.
The acid generator used in the present invention can be selected from compounds generally used as an acid generator.
That is, it generates an acid upon irradiation with actinic rays or radiation used for photoinitiators of photocationic polymerization, photoinitiators of photoradical polymerization, photodecolorants of dyes, photochromic agents, or microresists. Known compounds and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Preferred compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII), and (ZIII).

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.

The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z1-1), (Z1-2) and (Z1-3) described later.

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  More preferable examples of the (ZI) component include compounds (Z1-1), (Z1-2), and (Z1-3) described below.

Compound (Z1-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and the like.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.

  The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (eg, having 1 to 15 carbon atoms), a cycloalkyl group (eg, having 3 to 15 carbon atoms), an aryl group (eg, having 6 to 6 carbon atoms). 14), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group and the like may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl having 1 to 4 carbon atoms. Group, an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Examples of the non-nucleophilic anion as X ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  Examples of the aliphatic group in the aliphatic sulfonate anion include, for example, an alkyl group having 1 to 30 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec- Butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl And an eicosyl group and a cycloalkyl group having 3 to 30 carbon atoms, specifically, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a boronyl group, and the like.

  The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

  The alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent.

  Examples of such substituents include nitro groups, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), carboxyl groups, hydroxyl groups, amino groups, cyano groups, and alkoxy groups (preferably having 1 to 5 carbon atoms). ), A cycloalkyl group (preferably 3 to 15 carbon atoms), an aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group (preferably 2 to 12 carbon atoms). ), An alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the aliphatic group in the aliphatic carboxylate anion include those similar to the aliphatic group in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aromatic groups as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.

  The aliphatic group, aromatic group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent include aliphatic sulfonic acid The same halogen atom, alkyl group, cycloalkyl group, alkoxy group, alkylthio group and the like as in the anion can be exemplified.

  Examples of the sulfonylimide anion include saccharin anion.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. These alkyl groups may have a substituent, and examples of the substituent include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, and the like, which are substituted with a fluorine atom. Alkyl groups are preferred.

  Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

Examples of the non-nucleophilic anion of X ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is particularly preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, an aromatic sulfonic acid anion having a fluorine atom, most preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Next, the compound (Z1-2) will be described.
The compound (Z1-2) is a compound when R _{201 to} R ₂₀₃ in the general formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, most preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R _{201 to} R ₂₀₃ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. Butyl group, pentyl group and the like. More preferable examples of the alkyl group include a 2-linear or branched oxoalkyl group and an alkoxycarbonylmethyl group.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

  The 2-oxoalkyl group may be linear, branched or cyclic, and preferably includes a group having> C = O at the 2-position of the above alkyl group or cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

  The compound (Z1-3) is a compound represented by the following general formula (Z1-3), and is a compound having a phenacylsulfonium salt structure.

R _1c to R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c represent a hydrogen atom, an alkyl group, or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.

Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _7c is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, A linear or branched pentyl group can be exemplified.

The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group and a cyclohexyl group.

The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl groups and cycloalkyl groups as R _{1c to} R _{7c, such} as a 2-oxoalkyl group and a 2-oxocycloalkyl group. An alkoxycarbonylmethyl group is more preferable.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .

Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.

The alkyl group as R ₂₀₄ to R ₂₀₇ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group).

The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group.

The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Preferred examples of the acid generator include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

In general formulas (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represents an aryl group.

R ₂₀₆ , R ₂₀₇ and R ₂₀₈ are an alkyl group, a cycloalkyl group or an aryl group, and these are the same as the alkyl group, cycloalkyl group or aryl group as R _{204 to} R ₂₀₇ .
A represents an alkylene group, an alkenylene group or an arylene group.

  Among the acid generators, compounds represented by the general formulas (ZI) to (ZIII) are more preferable.

Particularly preferred as the acid generator in the present invention is one represented by the following general formula (I).

In general formula (I),
R ₁ represents an alkyl group, an alicyclic hydrocarbon group, a hydroxyl group, a carboxyl group, an alkoxy group or a halogen atom.
y represents 0 or an integer of 1 to 5 independently of each other. When y is an integer of 2 or more, two or more R _{1 s} may be the same or different.
Q ₁ represents an alkyl group substituted with a fluorine atom, a cycloalkyl group substituted with a fluorine atom, an aryl group substituted with a fluorine atom or an aryl group substituted with a fluorinated alkyl group.

As the alkyl group for R ₁ , a linear or branched alkyl group having 1 to 15 carbon atoms is preferable, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, and a t-butyl group. Can be mentioned.
Examples of the alicyclic hydrocarbon group for R ₁ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
Examples of the alkyl group substituted with the fluorine atom of Q ₁ include, for example, —CF ₃ , —C ₂ F ₅ , —n—C ₃ F ₇ , —CF (CF ₃ ) ₂ , —CH (CF ₃ ) ₂ , _{-CF 2 (CH 2) 3 CH} 3, - (CF 2) 2 OCF 2 CF 3, - (CF 2) 2 O (CH 2) 3 CH 3, - (CF 2) 2 O (CH 2) 13 CH ₃ , -n-C ₄ F ₉ , -t-C ₄ F ₉ , -CF [(CF ₂ ) ₃ CF ₃ ] ₂ , -C [(CF ₂ ) ₃ CF ₃ ] ₃ ,-(CF ₂ ) _{4 O (CH 2) 17 CH 3} , -n-C 8 F 17, -n-C 11 F 23, - (CF 2) such as _{2 O (CF 2) 2 (} CH 2) 3 CH 3 and the like.
Examples of the aryl group substituted with the fluorine atom of Q ₁ include 2,3,4,5,6-pentafluorophenyl group, 2,3,4-trifluorophenyl group, 2,4-difluorophenyl group, 4-fluorophenyl group, 4-undecanyloxy-2,3,5,6-tetrafluorophenyl group and the like can be mentioned.
Examples of the aryl group substituted with the fluorinated alkyl group of Q ₁ include, for example, 3-trifluoromethylphenyl group, 3,5-bis (trifluoromethyl) phenyl group, 4-trifluoromethylphenyl group, 4-n -Nonafluorobutylphenyl group etc. are mention | raise | lifted.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, examples of particularly preferable compounds are listed below.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator in the resist composition for immersion exposure is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably, based on the total solid content of the resist composition. Is 1-7 mass%.

(C) A dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as a “dissolution inhibiting compound”) that is decomposed by the action of an acid to increase the solubility in an alkaline developer.
The resist composition for immersion exposure of the present invention contains a dissolution inhibiting compound (hereinafter also referred to as “dissolution inhibitor”) having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer. It is preferable to do.
As a dissolution inhibitor, a fat containing an acid-decomposable group, such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724,355 (1996), in order not to lower the permeability of 220 nm or less. Cyclic or aliphatic compounds are preferred. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the resin as the component (A).
The molecular weight of the dissolution inhibitor in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution inhibitor is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, based on the total solid content of the resist composition for immersion exposure.

  Although the specific example of a dissolution inhibitor is shown below, it is not limited to these.

(D) Basic compound The resist composition for immersion exposure according to the present invention preferably further contains a basic compound. As the basic compound, for example, a nitrogen-containing basic compound, a basic ammonium salt, a basic sulfonium salt, a basic iodonium salt, or the like may be used as long as it does not deteriorate sublimation or resist performance.

  The basic compound is a component having an action of controlling a diffusion phenomenon in a resist film of an acid generated from an acid generator by exposure and suppressing an undesirable chemical reaction in a non-exposed region. By compounding such a basic compound, the storage stability of the resist composition for immersion exposure that can control the diffusion phenomenon of the acid generated from the acid generator upon exposure in the resist film is improved, and as a resist. In addition, the resolution of the resist pattern can be further improved, and a change in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to development processing can be suppressed, and a composition having excellent process stability can be obtained.

  Examples of the nitrogen-containing basic compound include primary, secondary and tertiary aliphatic amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, and compounds having a sulfonyl group. Examples thereof include nitrogen compounds, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide derivatives, imide derivatives, and nitrogen-containing compounds having a cyano group.

  As aliphatic amines, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert-amylamine, cyclopentylamine, hexylamine, cyclohexylamine, Heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di -Sec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine , Dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepentamine, trimethylamine, triethylamine, tri-n-propylamine , Triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine, tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, trinonylamine Decylamine, tridodecylamine, tricetylamine, N, N, N ′, N′-tetramethylmethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N N ', N'-tetramethyl-tetraethylenepentamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, benzyldimethylamine, and the like.

  Aromatic amines and heterocyclic amines include aniline derivatives such as aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, N, N-dimethyltoluidine, etc.), diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (eg pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4 -Dimethylpyro , 2,5-dimethylpyrrole, N-methylpyrrole, etc.), oxazole derivatives (eg oxazole, isoxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4 -Methyl-2-phenylimidazole, etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.) ), Imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine) Trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4- Pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1-ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, Piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (eg quinoline, 3-quinolinecarbonitrile) Etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives Guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives and the like.

  Examples of the nitrogen-containing compound having a carboxy group include aminobenzoic acid, indolecarboxylic acid, amino acid derivatives (for example, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, phenylalanine. , Threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine) and the like.

  Examples of the nitrogen-containing compound having a sulfonyl group include 3-pyridinesulfonic acid and pyridinium p-toluenesulfonate.

  Examples of the nitrogen-containing compound having a hydroxyl group include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N- Diethylethanolamine, triisopropanolamine, 2,2′-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- ( 2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) ethyl] piperazine, piperidineethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2- Hydroxyethyl ) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, 8-hydroxyeurolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2 -Pyrrolidine ethanol, 1-aziridine ethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) isonicotinamide and the like are exemplified.

  Examples of amide derivatives include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like.

  Examples of imide derivatives include phthalimide, succinimide, maleimide and the like.

  Specific examples of the nitrogen-containing compound having a cyano group include 3- (diethylamino) propiononitrile, N, N-bis (2-hydroxyethyl) -3-aminopropiononitrile, N, N-bis (2- Acetoxyethyl) -3-aminopropiononitrile, N, N-bis (2-formyloxyethyl) -3-aminopropiononitrile, N, N-bis (2-methoxyethyl) -3-aminopropiononitrile, N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropiononitrile, methyl N- (2-cyanoethyl) -N- (2-methoxyethyl) -3-aminopropionate, N- (2 -Cyanoethyl) -N- (2-hydroxyethyl) -3-aminopropionic acid methyl, N- (2-acetoxyethyl) -N- (2-cyanoethyl) Methyl 3-aminopropionate, N- (2-cyanoethyl) -N-ethyl-3-aminopropiononitrile, N- (2-cyanoethyl) -N- (2-hydroxyethyl) -3-aminopropiononitrile, N- (2-acetoxyethyl) -N- (2-cyanoethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- (2-formyloxyethyl) -3-aminopropiononitrile, N -(2-cyanoethyl) -N- (2-methoxyethyl) -3-aminopropiononitrile, N (2-cyanoethyl) -N- [2- (methoxymethoxy) ethyl] -3-aminopropiononitrile, N -(2-cyanoethyl) -N- (3-hydroxy-1-propyl) -3-aminopropiononitrile, N- (3-acetoxy-1-propionitrile ) -N- (2-cyanoethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- (3-formyloxy-1-propyl) -3-aminopropiononitrile, N- (2- Cyanoethyl) -N-tetrahydrofurfuryl-3-aminopropiononitrile, N, N-bis (2-cyanoethyl) -3-aminopropiononitrile, diethylaminoacetonitrile, N, N-bis (2-hydroxyethyl) aminoacetonitrile N, N-bis (2-acetoxyethyl) aminoacetonitrile, N, N-bis (2-formyloxyethyl) aminoacetonitrile, N, N-bis (2-methoxyethyl) aminoacetonitrile, N, N-bis [ 2- (methoxymethoxy) ethyl] aminoacetonitrile, N-cyanomethyl-N- (2- Methoxyethyl) -3-aminopropionate methyl, N-cyanomethyl-N- (2-hydroxyethyl) -3-aminopropionate methyl, N- (2-acetoxyethyl) -N-cyanomethyl-3-aminopropionate methyl N-cyanomethyl-N- (2-hydroxyethyl) aminoacetonitrile, N- (2-acetoxyethyl) -N- (cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (2-formyloxyethyl) aminoacetonitrile, N -Cyanomethyl-N- (2-methoxyethyl) aminoacetonitrile, N-cyanomethyl-N- [2- (methoxymethoxy) ethyl] aminoacetonitrile, N- (cyanomethyl) -N- (3-hydroxy-1-propyl) amino Acetonitrile, N- (3-acetoxy-1- (Lopyl) -N- (cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (3-formyloxy-1-propyl) aminoacetonitrile, N, N-bis (cyanomethyl) aminoacetonitrile, 1-pyrrolidinepropiononitrile, 1- Piperidine propiononitrile, 4-morpholine propiononitrile, 1-pyrrolidine acetonitrile, 1-piperidine acetonitrile, 4-morpholine acetonitrile, cyanomethyl 3-diethylaminopropionate, N, N-bis (2-hydroxyethyl) -3-aminopropion Cyanomethyl acid, cyanomethyl N, N-bis (2-acetoxyethyl) -3-aminopropionate, cyanomethyl N, N-bis (2-formyloxyethyl) -3-aminopropionate, N, N-bis (2- Me Xymethyl) -3-aminopropionate, cyanomethyl N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionate, 3-diethylaminopropionic acid (2-cyanoethyl), N, N-bis (2 -Hydroxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis (2-acetoxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis (2-formyloxyethyl) ) -3-Aminopropionic acid (2-cyanoethyl), N, N-bis (2-methoxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionic acid (2-cyanoethyl), cyanomethyl 1-pyrrolidinepropionate, 1-piperidine pro Examples include cyanomethyl pionate, cyanomethyl 4-morpholine propionate, 1-pyrrolidine propionic acid (2-cyanoethyl), 1-piperidinepropionic acid (2-cyanoethyl), 4-morpholine propionic acid (2-cyanoethyl).

  As the nitrogen-containing basic compound, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [ 2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidines, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, anilines, hydroxyalkylanilines, 4,4′-diaminodiphenyl ether , Pyridinium p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium lactate, triethylamine, tributylamine, tripentylamine, tri-n-octylami , Tri-i-octylamine, tris (ethylhexyl) amine, tridecylamine, tridodecylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, Tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) ) Propane, 2- (3- Aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) Propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2- Tri (cyclo) alkylamines such as dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tricyclohexylamine, aniline, N -Methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-ni Roaniline, diphenylamine, triphenylamine, naphthylamine, aromatic amines such as 2,6-diisopropylaniline, polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, Nt-butoxycarbonyldi-n-octyl Amine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt -Butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, N -T-Butoxyca Bonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N′-di -T-butoxycarbonyl-1,7-diaminoheptane, N, N'-di-t-butoxycarbonyl-1,8-diaminooctane, N, N'-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N′-di-t-butoxycarbonyl- 4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt Butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, urea Methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea, imidazole, 4-methylimidazole, Imidazoles such as 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine , 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine and other pyridines, piperazine, 1- (2- Piperazines such as hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, etc. be able to.

  Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, 4-hydroxypiperidine, 2,2,6,6-tetramethyl-4-hydroxypiperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, 4 , 4'-diaminodiphenyl ether, triethylamine, tributylamine, tripentylamine, tri-n-octylamine, tris (ethylhexyl) amine, tridodecylamine, N, N-di-hydroxyethylaniline, N-hydroxyethyl-N- Nitrogen-containing basic compounds such as ethylaniline are particularly preferred. Yes.

In the resist composition for immersion exposure according to the present invention, a basic ammonium salt can be further used as the basic compound. Specific examples of the basic ammonium salt include the following compounds, but are not limited thereto.
Specifically, ammonium hydroxide, ammonium triflate, ammonium pentaflate, ammonium heptaflate, ammonium nonaflate, ammonium undecaflate, ammonium tridecaflate, ammonium pentadecaflate, ammonium methylcarboxylate, ammonium ethylcarboxylate, Ammonium propyl carboxylate, ammonium butyl carboxylate, ammonium heptyl carboxylate, ammonium hexyl carboxylate, ammonium octyl carboxylate, ammonium nonyl carboxylate, ammonium decyl carboxylate, ammonium undecyl carboxylate, ammonium dodecadecyl carboxylate, ammonium salt Decyl carboxylate, ammonium tetradecyl carboxylate, ammonium pentadecyl carboxylate, ammonium hexadecyl carboxylate, ammonium heptadecyl carboxylate, ammonium octadecyl carboxylate and the like.

  Specific examples of ammonium hydroxide include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, and tetraheptyl. Ammonium hydroxide, methyl trioctyl ammonium hydroxide, tetraoctyl ammonium hydroxide, didecyl dimethyl ammonium hydroxide, tetrakisdecyl ammonium hydroxide, dodecyl trimethyl ammonium hydroxide, dodecyl ethyl dimethyl ammonium hydroxide, didodecyl dimethyl ammonium hydroxide, Tridodecylmethylammonium hydro Side, myristylmethylammonium hydroxide, dimethylditetradecylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octadecyltrimethylammonium hydroxide, dimethyldioctadecylammonium hydroxide, tetraoctadecylammonium hydroxide, diallyldimethylammonium hydroxide, (2 -Chloroethyl) -trimethylammonium hydroxide, (2-bromoethyl) trimethylammonium hydroxide, (3-bromopropyl) -trimethylammonium hydroxide, (3-bromopropyl) triethylammonium hydroxide, glycidyltrimethylammonium hydroxide, choline hydroxy (R)-(+)-(3-chloro-2-hydro Cypropyl) trimethylammonium hydroxide, (S)-(−)-(3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (2- Aminoethyl) -trimethylammonium hydroxide, hexamethonium hydroxide, decamethonium hydroxide, 1-azoniapropellan hydroxide, petronium hydroxide, 2-chloro-1,3-dimethyl-2-imidazolinium hydroxy And 3-ethyl-2-methyl-2-thiazolinium hydroxide.

The basic compound can be used alone or in combination of two or more, and it is more preferable to use two or more.
The amount of the basic compound used is generally 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid content of the resist composition for immersion exposure, as a total amount.

(E) Surfactant The resist composition for immersion exposure of the present invention preferably further comprises (E) a surfactant, and is a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon It is more preferable to contain any one of a system surfactant, a surfactant having both a fluorine atom and a silicon atom, or two or more thereof.

When the resist composition for immersion exposure of the present invention contains the surfactant (E), adhesion and development defects can be obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A small resist pattern can be provided.
Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, and R08. (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group List union It can be.

  In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Te - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

  In the present invention, a surfactant represented by the following general formula (W) can also be used.

In general formula (W),
R _w represents a hydrogen atom or an alkyl group.
m represents an integer of 1 to 30.
n represents an integer of 0 to 3.
p represents an integer of 0 to 5.

The alkyl group for R _w is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, or a t-butyl group. And a methyl group, an ethyl group, and a propyl group are more preferable.

  In general formula (W), it is more preferable that m is an integer of 1 to 25, n is an integer of 0 to 2, and p is an integer of 0 to 3.

Preferable specific examples of the surfactant represented by the general formula (W) include, for example, PF636 which is a commercially available product (n = 0, m = 6, p = 1, R ₁ = methyl group in the general formula (W)). PF6320 (n = 0, m = 20, p = 1, R ₁ = methyl group), PF656 (n = 1, m = 6, p = 1, R ₁ = methyl group in the general formula (W)), PF6520 (In general formula (W), n = 1, m = 20, p = 1, R ₁ = methyl group) (above, manufactured by OMNOVA) and the like can be mentioned.

  These surfactants may be used alone or in several combinations.

  (E) The amount of the surfactant used is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, based on the total amount of the resist composition for immersion exposure (excluding the solvent). .

(F) Organic solvent Solvents that can be used when preparing the resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate ester, alkoxy Examples thereof include alkyl propionate, cyclic lactone having 4 to 10 carbon atoms, monoketone compound having 4 to 10 carbon atoms which may contain a ring, alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate and the like.

Examples of the alkylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl Preferred examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.
Preferred examples of the alkylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferred examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate and butyl lactate.
Preferable examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate.

  Examples of the cyclic lactone having 4 to 10 carbon atoms include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ- Caprolactone, γ-octanoic lactone, and α-hydroxy-γ-butyrolactone are preferred.

  Examples of the monoketone compound having 4 to 10 carbon atoms and optionally containing a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4- Methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2 -Hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4 -Heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5- Xen-2-one, 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopenta Non, cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcyclo Preferred are heptanone and 3-methylcycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.
Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.
As a solvent which can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid -2- (2-ethoxyethoxy) ethyl and propylene carbonate are mentioned.
In the present invention, the above solvents may be used alone or in combination of two or more.

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.
Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.
Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone is most preferred.
The mixing ratio (weight) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by weight or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.

(G) Alkali-soluble resin The positive resist composition of the present invention may further contain an acid-decomposable group, (G) a resin that is insoluble in water and soluble in an alkaline developer, This improves the sensitivity.
In the present invention, a novolak resin having a molecular weight of about 1000 to 20000 and a polyhydroxystyrene derivative having a molecular weight of about 3000 to 50000 can be used as such a resin, since these have a large absorption with respect to light of 250 nm or less. It is preferable to use a partly hydrogenated amount or 30% by weight or less of the total resin amount.
A resin containing a carboxyl group as an alkali-soluble group can also be used. The resin containing a carboxyl group preferably has a monocyclic or polycyclic alicyclic hydrocarbon group for improving dry etching resistance. Specifically, a methacrylic acid ester and (meth) acrylic acid copolymer having an alicyclic hydrocarbon structure that does not exhibit acid decomposability, or a (meth) acrylic acid ester having an alicyclic hydrocarbon group having a carboxyl group at the terminal And the like.

(H) Carboxylic acid onium salt Examples of the (H) carboxylic acid onium salt in the present invention include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, the (H) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, it is preferable that the carboxylate residue of the (H) carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. As a particularly preferable anion moiety, a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms is preferable. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

  Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , 2-bistrifluoromethylpropionic acid anion and the like.

  These (H) carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

  The content of the (H) carboxylic acid onium salt in the composition is suitably 0.1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 1 to the total solid content of the composition. -7% by weight.

Other Additives In the resist composition for immersion exposure according to the present invention, if necessary, a dye, a plasticizer, a photosensitizer, and a compound that promotes solubility in a developer (for example, phenol having a molecular weight of 1000 or less). A compound, an alicyclic compound having a carboxyl group, or an aliphatic compound).

Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

(how to use)
The resist composition for immersion exposure according to the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
That is, the resist composition for immersion exposure is applied to a substrate (eg, silicon / silicon dioxide coating) used for the manufacture of precision integrated circuit elements by an appropriate coating method such as a spinner or a coater. 50 to 500 nm). After application, the resist film is washed with immersion water as necessary. The washing time is usually 5 seconds to 5 minutes.
Subsequently, the resist applied by spin or bake is dried to form a resist film, and then exposed through a mask or the like for pattern formation and exposed (immersion exposure) through immersion water. For example, the exposure is performed in a state where the space between the resist film and the optical lens is filled with the immersion liquid. Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally. After exposure, the resist film is washed with immersion water as necessary. The time is usually 5 seconds to 5 minutes. Subsequently, spin or / and baking is preferably performed, and development and rinsing are performed to obtain a good pattern. The baking temperature is usually 30 to 300 ° C. From the above-mentioned PED point, it is better that the time from the exposure to the baking process is short.
Here, the exposure light is preferably far ultraviolet rays having a wavelength of 250 nm or less, more preferably 220 nm or less. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-rays, and the like.
Incidentally, it is considered that the change in performance observed when the resist is applied to immersion exposure is derived from the contact of the resist surface with the immersion liquid.

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist. In the case of an ArF excimer laser (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.
When water is used as the immersion liquid, the surface tension of the water is decreased and the surface activity is increased, so that the resist layer on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained. On the other hand, when an opaque substance or impurities whose refractive index is significantly different from that of water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. Therefore, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.

In order to prevent the resist film from coming into direct contact with the immersion liquid between the resist film formed by the immersion exposure resist of the present invention and the immersion liquid, it is also called an immersion liquid hardly soluble film (hereinafter also referred to as “top coat”). ) May be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers.
When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.
The resolution is improved when there is no difference in refractive index between the topcoat and the immersion liquid. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the immersion liquid, so that the top coat for ArF immersion exposure is close to the refractive index of water (1.44). Is preferred. A thin film is more preferable from the viewpoint of transparency and refractive index.

In the development process, a developer is used as follows. Examples of the developer for the resist composition for immersion exposure include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, ethylamine, and n-propylamine. Secondary amines such as amines, diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxy Alkaline aqueous solutions such as quaternary ammonium salts such as pyrrole and cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants may be added in appropriate amounts to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, the content of this invention is not limited by this.
In addition, Examples 9 to 28 and Examples 31 to 39 are to be read as “reference examples”.
1. Synthesis of Resin (1) In a nitrogen stream, 13.8 g of propylene glycol monomethyl ether acetate and 9.2 g of propylene glycol monomethyl ether were placed in a three-necked flask and heated to 80 ° C. To this, 8.9 g of norbornane lactone methacrylate, 5.0 g of dihydroxyadamantane methacrylate, 7.9 g of isoadamantyl methacrylate, a propylene glycol monomethyl ether acetate solution of 3.5 g of the monomer of the following formula (A), and initiator V-601 (sum) A propylene glycol monomethyl ether solution (manufactured by Hikari Pure Chemical Co., Ltd., 8 mol% relative to the monomer) was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction mixture was poured into a mixed solvent of cooling after hexane / ethyl acetate, precipitated were collected by filtration powder, and dried, the resin (1) was obtained 22.8 g. The weight average molecular weight of the obtained resin was 8900, and the dispersity (Mw / Mn) was 2.22.
Resins (2) to (13) and comparative resins (Q1) and (Q2) were synthesized by the same method.
The structures, weight average molecular weights, and dispersities of the resins (1) to (13) and the comparative resins (Q1) and (Q2) are collectively shown below.

2. Adjustment of resist compositions 1 to 28 and comparative resist composition <Registration adjustment>
Components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid concentration of 5.5% by mass, and this was filtered through a 0.05 μm microfilter to prepare a positive resist solution.

[Static contact angle measurement of resist film]
Each resist composition shown in Table 1 was applied on a silicon wafer and baked at 110 ° C. for 60 seconds to form a 150 nm resist film. After dropping one drop of pure water on this resist film, the static contact angle when 5 seconds passed was measured using an automatic contact angle meter (CA-V type, manufactured by Kyowa Interface Chemical Co., Ltd.) in the θ / 2 method. Automatic measurement. The same measurement was repeated at N = 5 for one type of resist film, and the average value was defined as the static contact angle with respect to pure water. Furthermore, the measurement was carried out in the same manner as described above except that the solution hanging on the resist film was changed to a 2.38% tetramethylammonium hydroxide aqueous solution (alkali developer), and the contact angle with respect to the alkali developer was determined.

[Resolution evaluation (immersion exposure)]
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. Each resist composition shown in Table 1 was applied thereon and baked at 110 ° C. for 60 seconds to form a 100 nm resist film. The resist film thus obtained was subjected to two-beam interference exposure using pure water as the immersion liquid (immersion exposure). In the two-beam interference exposure (immersion), as shown in FIG. 1, a laser 1, an aperture 2, a shutter 3, three reflecting mirrors 4, 5, 6 and a condenser lens 7 are used, and a prism 8, The wafer 10 having an antireflection film and a resist film was exposed through an immersion liquid (pure water) 9. The wavelength of the laser 1 was 193 nm. Immediately after exposure, the film was heated at 120 ° C. or 130 ° C. for 60 seconds, developed with a tetramethylammonium hydroxide aqueous solution (2.38%) for 60 seconds, rinsed with pure water, and spin-dried to obtain a resist pattern. Here, the immersion exposure uses the prisms in FIG. 1 that sequentially form optical images of 65 nm, 60 nm, 55 nm, 50 nm, and 45 nm line and space patterns, and the resist pattern is actually resolved to how many nm. It was observed using a length measuring SEM (S-9260 manufactured by Hitachi), and the resolution of the resist composition was evaluated. A smaller number indicates that a finer pattern can be resolved.

[Evaluation of acid elution amount]
The prepared resist composition was applied to an 8-inch silicon wafer and baked at 115 ° C. for 60 seconds to form a 150 nm resist film. After exposing the resist film with an exposure machine having a wavelength of 193 nm at an entire surface of 50 mJ / cm ² , 5 ml of pure water deionized using an ultrapure water production apparatus (Milli-QJr., Manufactured by Nihon Millipore) was applied on the resist film. It was dripped in. Water was placed on the resist film for 50 seconds, the water was collected, and the acid elution concentration was quantified by LC-MS.
LC device: Waters 2695
MS equipment: esquire 3000plus from Bruker Daltonics
The MS detection intensity of ionic species having a mass of 299 (corresponding to nonaflate anion) was measured with the LC-MS apparatus, and the elution amount of nonafluorobutanesulfonic acid was calculated. Similarly, the MS detection intensity of an ionic species having a mass of 413 (corresponding to 4-dodecyloxy-2,3,5,6-tetrafluorobenzenesulfonate anion) was measured, and 4-dodecyloxy-2,3,5,6 was measured. -The elution amount of tetrafluorobenzenesulfonic acid was calculated.

[Development defect evaluation]
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. Each resist composition shown in Table 1 was applied thereon and baked at 110 ° C. for 60 seconds to form a 150 nm resist film. After developing with a tetramethylammonium hydroxide aqueous solution (2.38%) for 60 seconds, rinsing with pure water, spin drying and post-baking at 90 ° C. for 90 seconds. The resist film thus obtained was examined for the number of development defects using a KLA-2112 machine manufactured by KLA-Tencor Corporation, and the obtained primary data value was taken as the number of development defects.
Table 1 shows the results.

  Hereinafter, the abbreviations in Table 1 are as follows.

N-1: N, N-diisopropylaniline N-2: 2,4,5-triphenylimidazole N-3: N, N-dihydroxyethylaniline N-4: trioctylamine

W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Mega W-2; Fuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon-based)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF-6520 (made by OMNOVA)

SL-1: Propylene glycol monomethyl ether acetate SL-2: Propylene glycol monomethyl ether SL-3: Cyclohexanone SL-4: Propylene carbonate

I-1: t-butyl lithocholic acid I-2: t-butyl adamantanecarboxylate In the table, the ratio when a plurality of photoacid generators or solvents are used is a mass ratio.

  From the above results, it can be seen that the resist composition of the present invention has good resolution at the time of immersion exposure, and the occurrence of defects after development is reduced. Furthermore, the amount of the generated acid dissolved in pure water as an immersion medium is also reduced, indicating that the resist composition is suitable for immersion exposure.

It is the schematic which shows a static contact angle. It is the schematic which shows the contact angle by (theta) / 2 method. It is the schematic which shows a dynamic contact angle. It is the schematic which shows two-beam interference exposure.

Claims (7)

(A) a resin having a repeating unit having a group represented by the following general formula (II) and a repeating unit represented by the general formula (AIIa), and having increased solubility in an alkali developer by the action of an acid; and (B ) Containing a compound that generates an acid upon irradiation with actinic rays or radiation, and has a static contact angle with respect to pure water of 72 ° or more when a coating film is formed on the substrate, and 2.38% tetra A positive resist composition for immersion exposure, wherein the static contact angle with respect to an aqueous solution of methylammonium hydroxide is 70 ° or less (however, 5 to 20 parts by mass of a compound that generates an acid upon irradiation with actinic rays or radiation) And a positive photosensitive composition containing 100 parts by mass of a resin having a fluorine atom and a group that decomposes by the action of an acid and increases the solubility in an alkali developer).

In general formula (II):
R _f1 and R _f2 each independently represent a hydrogen atom, an alkyl group or a fluoroalkyl group. However, at least one of R _f1 and R _f2 is a fluoroalkyl group.

In general formula (AIIa),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl -thieno group.
R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.   2. The immersion exposure according to claim 1, wherein the static contact angle with respect to pure water is 74 ° or more, and the static contact angle with respect to a 2.38% tetramethylammonium hydroxide aqueous solution is 69 ° or less. Positive resist composition.   2. The immersion exposure according to claim 1, wherein the static contact angle with respect to pure water is 76 ° or more and the static contact angle with respect to a 2.38% tetramethylammonium hydroxide aqueous solution is 68 ° or less. Positive resist composition. The positive resist composition for immersion exposure according to any one of claims 1 to 3, wherein the resin of component (A) further has a repeating unit represented by the following general formula (PA).

here,
R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents.
Rp1 represents one of the following general formulas (pI) to (pV).

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R ₁₂ to R ₁₄ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. Provided that at least one of R ₁₂ to R ₁₄ represents a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represent a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring. The positive resist composition for immersion exposure according to any one of claims 1 to 4, wherein the resin of component (A) further has a repeating unit represented by the following general formula (AI).

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these.
V represents a group represented by any one of the following general formulas (LC1-1) to (LC1-16).

Where
Rb ₂ represents a substituent.
n ₂ represents an integer of 0 to 3.   The immersion exposure according to any one of claims 1 to 5, wherein the content of the repeating unit having a group represented by the general formula (II) in the resin of the component (A) is 5 to 30 mol%. Positive resist composition.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 1, subjecting the resist film to immersion exposure, and developing.

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