JP2009258586A - Resist composition for negative type development, and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition for negative type development superior in pattern collapse performance and trench pattern resolution in patterning with negative type development in order to stably form a highly precise fine pattern for manufacturing a highly integrated and highly precise electronic device, and to provide a pattern forming method using the same. <P>SOLUTION: The resist composition for negative type development contains (A) a resin for reducing solubility to a negative type developer due to action of acid by including an acid decomposition repeating unit of a specific structure, (B) a photoacid generator, and (C) a solvent. The pattern forming method using it is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a negative developing resist composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication lithography processes, and a pattern using the same. The present invention relates to a forming method. In particular, the present invention relates to a negative developing resist composition suitable for exposure with an ArF exposure apparatus and an immersion projection exposure apparatus using far ultraviolet light having a wavelength of 300 nm or less as a light source, and a pattern forming method using the same. .

  Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. An example of a positive-type chemical amplification image forming method will be described. When exposed, the acid generator in the exposed area decomposes to generate an acid, and the acid generated in the exposure bake (PEB) is a reaction catalyst. Is used to change an alkali-insoluble group to an alkali-soluble group, and an exposed portion is removed by alkali development.

With the miniaturization of semiconductor elements, the wavelength of an exposure light source has been shortened and the projection lens has a high numerical aperture (high NA). Currently, an exposure machine using an ArF excimer laser having a 193 nm wavelength as a light source has been developed. 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
Where 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.

As a technique for increasing the resolving power, a so-called immersion method in which a high refractive index liquid (hereinafter also referred to as “immersion liquid”) is filled between the projection lens and the sample has been proposed.
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 a projection optical system with 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.

Further, as a technique for further improving the resolution, a double exposure technique (Double Exposure Technology) and a double patterning technique (Double Patterning Technology) have been proposed. This is to reduce k ₁ in the above-described resolving power formula, and is positioned as a technique for increasing the resolving power.

Conventionally, pattern formation of electronic devices such as semiconductor elements is performed by reducing and transferring a mask or reticle pattern, which is 4-5 times the size of the pattern to be formed, to an object to be exposed such as a wafer using a reduction projection exposure apparatus. It was.
However, with the miniaturization of dimensions, the conventional exposure method has a problem in that the light irradiated to adjacent patterns interferes with each other and the optical contrast is reduced. The design is divided into two or more, each mask is exposed independently, and an image is synthesized. In these double exposure methods, it is necessary to divide the design of the exposure mask, re-synthesize the image on the object to be exposed (wafer), and the pattern on the reticle faithfully adheres to the object to be exposed. It is necessary to devise the division of the mask design so that it can be reproduced.
An example in which the effect of these double exposure methods is studied for transferring a fine image pattern of a semiconductor element is introduced in Patent Document 1 and the like.
Recent double exposure technology progress is reported in Non-Patent Document 1, Non-Patent Document 2, Non-Patent Document 3, and the like.

However, if the conventional resist composition is simply applied to the conventional resist process for pattern formation, these double exposure methods require pattern formation near the resolution limit of the resist. The problem is that the lithography performance cannot be obtained.
That is, as disclosed in Patent Document 2 and the like, a resist composition containing a resin whose polarity increases by exposure is applied to a substrate, exposed, and an exposed portion of the resist film is dissolved and developed with an alkaline developer. A resist composition containing a resin whose molecular weight increases by exposure, as introduced in the process or Patent Document 3, is applied to the substrate, exposed, and the unexposed portion of the resist film is dissolved and developed with an alkaline developer. If the pattern formation process is applied to a double exposure process, sufficient resolution performance cannot be obtained.

At present, as a developing solution for g-line, i-line, KrF, ArF, EB, EUV lithography, an aqueous alkaline developer of 2.38% by mass TMAH (tetramethylammonium hydroxide) is widely used.
As a developer other than the above, for example, Patent Document 4 discloses an aliphatic solution for dissolving and developing an exposed portion of a resist material containing a copolymer of a styrene monomer and an acrylic monomer. A developer containing a linear ether solvent or an aromatic ether solvent and a ketone solvent having 5 or more carbon atoms is described. Further, Patent Document 5 discloses that at least 2 acetate groups, ketone groups, ether groups, and phenyl groups are used for dissolving and developing an exposed portion of a resist material that has been polymerized to have a low molecular weight when irradiated with radiation. And a developer having a molecular weight of 150 or more. Patent Document 6 discloses that the number of carbon atoms for developing an unexposed portion of a resist material mainly composed of a photosensitive polyhydroxyether resin obtained by a reaction between a polyhydroxyether resin and glycidyl (meth) acrylate. A developer characterized by using as a developer a mixed solvent containing 50% by mass or more of an aromatic compound having 6 to 12 carbon atoms or an aromatic compound having 6 to 12 carbon atoms is described.
Patent Document 7 describes a developer containing an organic solvent, particularly a halogenated organic solvent, for developing an exposed portion of a resist composition containing a specific resin containing fluorine. . Patent Document 8 discloses a group consisting of propylene glycol methyl ether acetate, cyclohexanone, butyrolactate, and ethyl lactate for developing an unexposed portion of a resist composition containing a specific polycyclic olefin polymer. A developer containing one or more selected solvents is described.
However, it is of course desirable to form a pattern with a comprehensively good performance, but it is extremely difficult to find an appropriate combination of resist composition, developer, rinse solution, and the like necessary for that purpose. This was the actual situation, and improvements were required. In particular, as the resolution line width of the resist becomes finer, improvement in pattern collapse performance and trench pattern resolution has been demanded.

In addition, in the combination of the resist composition and the developer described above, a specific resist composition is combined with a developer containing a high polarity alkaline developer or a low polarity organic solvent to provide a system for forming a pattern. Only. That is, as shown in FIG. 1, in a positive system (combination of a resist composition and a positive developer), a region having a high light irradiation intensity in an optical aerial image (light intensity distribution) is selectively dissolved and dissolved. Only the material to be removed and patterned is provided. On the other hand, the negative system (resist composition and negative developer) only provides a material system that selectively dissolves and removes areas with low light irradiation intensity to form a pattern. .
Here, the positive developer is a developer that selectively dissolves and removes the exposed portion that is equal to or higher than the predetermined threshold value represented by the dotted line in FIG. 1. The negative developer is the lower than the predetermined threshold value. A developer that selectively dissolves and removes the exposed portion. The development process using a positive developer is referred to as positive development (also referred to as a positive development process), and the development process using a negative developer is referred to as a negative development (also referred to as a negative development process). Call.

On the other hand, Patent Document 9 describes a double development technique as a double patterning technique for increasing resolution. In this example, a general chemical amplification image forming method is used, and by exposure, the polarity of the resin in the resist composition becomes high in a region where the light intensity is high, and low in a region where the light intensity is low. By utilizing this, positive development is performed by dissolving a high exposure area of a specific resist film in a high polarity developer, and negative development is performed by dissolving a low exposure area in a low polarity developer. . Specifically, as shown in FIG. 2, a region where the exposure amount E2 of the irradiation light 1 is dissolved using an alkaline aqueous solution as a positive developer, and a region where the exposure amount E1 is less than a specific organic solvent is negatively developed. It is dissolved as a liquid. As a result, as shown in FIG. 2, an intermediate exposure amount (E2-E1) region remains without being developed, and an L / S pattern 3 having a half pitch of the exposure mask 2 is formed on the wafer 4. Yes.
However, it is very difficult to select an optimal combination of a resist composition and a negative developer, and in the above example, developability when using a negative developer is deteriorated. There was a problem.
Furthermore, when forming a fine pattern by double development, it is not sufficient that the resolving power when using a negative developer or a positive developer alone is sufficient, and the negative developer and the positive developer are not sufficient. In either case, it has been required to exhibit good pattern resolution.

JP 2006-156422 A Japanese Patent Laid-Open No. 2001-109154 JP 2003-76019 A JP 2001-215731 A JP 2006-227174 A Japanese Patent Laid-Open No. 6-194847 Special Table 2002-525683 Special Table 2006-518779 Japanese Unexamined Patent Publication No. 2000-199953 SPIE Proc 5754,1508 (2005) SPIE Proc 5377,1315 (2004) SPIE Proc 61531K-1 (2006)

  The present invention solves the above-mentioned problems, and in order to stably form a high-precision fine pattern for manufacturing a highly integrated and high-precision electronic device, the pattern collapse performance in the patterning by negative development is improved. It is an object of the present invention to provide a negative developing resist composition having good trench pattern resolution and a pattern forming method using the same.

  The present invention has the following configuration, whereby the above object of the present invention is achieved.

[1]
(A) Resin containing a repeating unit represented by general formula (nI) or general formula (nII) and having reduced solubility in a negative developer by the action of an acid, (B) a photoacid generator, and (C) A negative resist composition containing a solvent.

In general formula (nI) and general formula (nII),
R ₁₃ ′ to R ₁₆ ′ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or a lactone structure. Represents a group.
X ₁ and X ₂ each independently represent a methylene group, an ethylene group, an oxygen atom or a sulfur atom.
n represents an integer of 0 to 2.
[2]
(A) (A) a resin containing a repeating unit represented by general formula (nI) or general formula (nII) and having reduced solubility in a negative developer by the action of an acid, (B) a photoacid generator, and (C) A step of applying a negative resist composition containing a solvent,
(A) exposure process,
(D) A pattern forming method comprising a step of developing using a negative developer.

In general formula (nI) and general formula (nII),
R ₁₃ ′ to R ₁₆ ′ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or a lactone structure. Represents a group.
X ₁ and X ₂ each independently represent a methylene group, an ethylene group, an oxygen atom or a sulfur atom.
n represents an integer of 0 to 2.
[3]
Further, (c) the pattern forming method according to [2], further comprising a step of developing using a positive developer.

  According to the present invention, it is possible to provide a negative developing resist composition having good pattern collapse performance and good trench pattern resolution in patterning by negative development, and a pattern forming method using the same. it can. Furthermore, according to the present invention, a pattern can be resolved in a multiple development process using both negative development and positive development.

Hereinafter, the best mode for carrying out the present invention will be described.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

  First, terms used in this specification will be described. There are two types of pattern formation methods: positive and negative. Both use the fact that the solubility of the resist film in the developer changes due to a chemical reaction triggered by light irradiation. The case where the part is dissolved in the developer is called a positive type, and the case where the non-irradiated part is dissolved in the developer is called a negative type. There are two types of developers used in this case, a positive developer and a negative developer. The positive developer is a developer that selectively dissolves / removes an exposed portion (also simply referred to as an exposed portion or an exposed portion) having a predetermined threshold value or more as indicated by a solid line in FIG. 1. What is a negative developer? A developer that selectively dissolves and removes an exposed portion (also referred to as an unexposed portion or an unexposed portion) having a predetermined threshold value or less. The development process using a positive developer is referred to as positive development (also referred to as a positive development process), and the development process using a negative developer is referred to as a negative development (also referred to as a negative development process). Call. Multiple development (also referred to as multiple development process) is a development system that combines a development process using the positive developer and a development process using the negative developer. In the present invention, the resist composition used for negative development is called a negative development resist composition, and the resist composition used for multiple development is called a multiple development resist composition. Hereinafter, when it is simply described as a resist composition, it means a negative developing resist composition. The negative type rinsing liquid represents a rinsing liquid containing an organic solvent, which is used in the washing step after the negative type developing step.

  With the negative development composition of the present invention, pattern collapse can be suppressed and the resolution of the trench pattern can be improved in patterning by negative development. In the present invention, the pattern collapse refers not only to a phenomenon in which the pattern is peeled off from the substrate, but also to a phenomenon in which the pattern is collapsed or broken from its middle or upper part.

In the present invention, as a technique for increasing the resolving power, as shown in FIG. 3, a developer (negative developer) that selectively dissolves and removes an exposed portion having a predetermined threshold value (b) or less, and (A) a general formula Having at least two types of repeating units selected from (pI) to (pV) having different partial structures,
Resin composition for negative development containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developer is reduced, (B) a compound that generates acid upon irradiation with actinic rays or radiation, and (C) a solvent. A new pattern forming method is proposed.

The negative developing resist composition of the present invention increases the solubility in a positive developing solution (preferably an alkaline developing solution) upon irradiation with actinic rays or radiation, and selectively exposes exposed portions having a predetermined threshold value (a) or more. A developer (positive developer) that exhibits excellent development characteristics with respect to a developer (positive developer) that is dissolved / removed in water, and that selectively dissolves / removes exposed areas that exceed a predetermined threshold (a). In combination with a developer (negative developer) that selectively dissolves and removes exposed areas below a predetermined threshold (b), and a resist composition for negative development, pattern formation by multiple development is possible. is there.
That is, as shown in FIG. 3, when a pattern element on an exposure mask is projected onto a wafer by light irradiation, a region having a high light irradiation intensity (an exposed portion having a predetermined threshold value (a) or more) is positively positioned. An optical aerial image (light) is obtained by dissolving / removing with a mold developer and dissolving / removing an area with a low light irradiation intensity (exposed portion below a predetermined threshold (b)) with a negative developer. A pattern having a resolution twice the frequency of the intensity distribution can be obtained.

  Therefore, the negative developing resist composition of the present invention can be suitably used as a multiple developing resist composition.

First, a pattern forming method using the negative developing composition of the present invention will be described.
(A) (a) containing a repeating unit represented by general formula (nI) or general formula (nII), increasing the polarity by the action of an acid, increasing the solubility in a positive developer, and a negative developer A step of applying a negative developing resist composition containing a resin having a reduced solubility in (b) a photoacid generator and (c) a solvent;
(A) exposure process,
(D) A pattern forming method comprising a step of developing using a negative developer.

In general formula (nI) and general formula (nII),
R ₁₃ ′ to R ₁₆ ′ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or a lactone structure. Represents a group.
X ₁ and X ₂ each independently represents a methylene group, an ethylene group, an oxygen atom or a sulfur atom.
n represents an integer of 0 to 2.

  The pattern formation method of the present invention preferably further includes (c) a step of developing using a positive developer. Thereby, a finer pattern can be formed. In the case of using a positive developer and a negative developer in combination, the order of the two developments may be either positive development or negative development first.

  The pattern forming method of the present invention preferably further includes (f) a step of washing using a rinse solution containing an organic solvent.

  The pattern forming method of the present invention preferably has (b) a heating step (also referred to as baking or PEB (post exposure bake)) after the exposure step.

  The pattern formation method of this invention can have (b) exposure process in multiple times.

  The pattern forming method of the present invention can include (e) a heating step (also referred to as baking or PEB (post exposure bake)) a plurality of times.

  In carrying out the pattern forming method of the present invention, (a) the acid-decomposable repeating unit represented by the general formula (I) is contained, the polarity is increased by the action of the acid, and the solubility in the positive developer is increased. And a negative resist composition containing (b) a photoacid generator and (c) a solvent, and (Ab) a negative developer (preferably an organic developer). )is required.

Further, (Ac) a positive developer (preferably an alkali developer) is preferably used.
Furthermore, it is preferable to use a negative developing rinse solution containing (Ad) an organic solvent.

  In the case of performing a pattern formation process using two types of developers, a positive developer and a negative developer, the order of development is not particularly limited, but after the first exposure, the positive developer or negative developer is used. It is preferable to perform development using a mold developer and then to perform negative or positive development with a developer different from the first development. Furthermore, after performing negative development, it is preferable to wash with a negative developing rinse containing an organic solvent.

As a method of forming a pattern, there are (a) a method using a chemical reaction such as polarity conversion, and (b) a method using a bond formation between molecules such as a crosslinking reaction and a polymerization reaction.
In resist material systems where the molecular weight of the resin increases due to intermolecular bonds such as cross-linking reactions and polymerization reactions, one resist material is positive for one developer and one for another developer. It was difficult to construct a system that would act on the negative type.

The resist composition is “a resin composition that contains a resin whose polarity is increased by the action of an acid and forms a film whose solubility in a negative developer is decreased by irradiation with actinic rays or radiation”.
The resist composition in the present invention contains a resin whose polarity is increased by the action of an acid, and not only the solubility in a negative developer is reduced by irradiation with actinic rays or radiation, but in particular an alkaline developer. Simultaneously increase the solubility in water and decrease the solubility in a developer containing an organic solvent.
That is, in the present invention, one resist composition simultaneously acts as a positive type for a positive developing solution and acts as a negative type for a negative developing solution.
In the present invention, as a positive developer, an alkaline developer (aqueous), as a negative developer,
An organic developer containing an organic solvent can be used.

In the present invention, it is important to control the “threshold” of the exposure amount (the exposure amount at which the film is solubilized or insolubilized in the developer in the light irradiation region). Accordingly, when performing pattern formation, the minimum exposure amount solubilized in the positive developer and the minimum exposure amount insolubilized in the negative developer so as to obtain a desired line width, that is, “ It is important to control the “threshold”.
More specifically, the “threshold value” can be obtained as follows.
That is, when the remaining film ratio relative to the exposure amount of the resist film is measured, the minimum exposure amount at which the remaining film ratio becomes 0% is set to the threshold value (a) with respect to the positive developer, and the remaining amount with respect to the negative developer. The minimum exposure amount at which the film rate becomes 100% can be defined as the threshold value (b). The threshold value (a) and threshold value (b) defined here are synonymous with the threshold value (a) and threshold value (b) in FIG.

As a method for controlling the threshold value, there are a method for controlling a material-related parameter of the resist composition and the developer and a parameter related to the process.
As the material-related parameters, it is effective to control various physical property values related to the solubility of the resist composition in the developer and the organic solvent, that is, SP value (solubility parameter), LogP value, and the like. Specifically, the polymer weight average molecular weight, molecular weight dispersity, monomer composition ratio, monomer polarity, monomer sequence, polymer blend, addition of low molecular additives, and the developer contained in the resist composition, Examples include developer concentration, addition of low molecular additives, addition of surfactants, and the like.
Process-related parameters include film formation temperature, film formation time, post-exposure post-heating temperature, time, development temperature, development time, developing device nozzle method (liquid filling method), post-development rinsing method Etc.
Therefore, in the pattern formation method using negative development and the pattern formation method by multiple development using both negative development and positive development, in order to obtain a good pattern, the above-mentioned material-related parameters and process parameters are appropriate. It is important to control and combine them.

  The pattern formation process using two types of developer, a positive developer and a negative developer, may be performed by a single exposure as described above, or may be performed by a process of performing two or more exposures. Good. That is, after the first exposure, development is performed using a positive developer or a negative developer, and then, after the second exposure, with a developer different from the first development, Perform negative or positive development.

  In the present invention, the film formed on the substrate contains (A) an acid-decomposable repeating unit represented by the general formula (nI) or (nII), and has a solubility in a negative developer by the action of an acid. It is a film formed by applying a negative resist composition containing a reducing resin, (B) a photoacid generator and (C) a solvent.

(A) Resin whose solubility in negative developer is reduced by the action of acid
The resin having a reduced solubility in a negative developer used in the negative developing resist composition of the present invention has an increased solubility in an alkaline developer due to the action of an acid, and a reduced solubility in an organic solvent. The resin has a group (hereinafter also referred to as “acid-decomposable group”) that decomposes by the action of an acid to generate an alkali-soluble group in the main chain or side chain of the resin, or in both the main chain and the side chain. Resin (also referred to as “acid-decomposable resin”, “acid-decomposable resin (A)” or “resin (A)”), having a polycyclic alicyclic hydrocarbon structure, and an alkali developer by the action of an acid More preferred is a resin that has increased solubility in organic solvents and reduced solubility in organic solvents.
That is, the acid-decomposable resin contains a repeating unit having an acid-decomposable group. The acid-decomposable group is a group in which a hydrogen atom of an alkali-soluble group is substituted with a group capable of leaving with an acid.
Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
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.
In addition, as a repeating unit which has an acid-decomposable group, the repeating unit represented by the below-mentioned general formula (pA) is preferable.

  The negative developing resist composition of the present invention containing a resin having a polycyclic alicyclic hydrocarbon structure, which increases the solubility in an alkaline developer by the action of an acid and decreases the solubility in an organic solvent. It can be suitably used when irradiating with laser light.

  The acid-decomposable resin (A) used in the negative developing resist composition of the present invention contains a repeating unit represented by the following general formula (nI) or general formula (nII).

In general formula (nI) and general formula (nII),
R ₁₃ ′ to R ₁₆ ′ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or a lactone structure. Represents a group.
X ₁ and X ₂ each independently represent a methylene group, an ethylene group, an oxygen atom or a sulfur atom.
n represents an integer of 0 to 2.

Examples of the halogen atom in R ₁₃ ′ to R ₁₆ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

As the alkyl group or cycloalkyl group of R ₁₃ ′ to R ₁₆ ′, an alkyl group having 1 to 20 carbon atoms is preferable, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a sec-butyl group, a tert -Butyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group can be mentioned. Part or all of the hydrogen atoms of the alkyl group may be substituted with a halogen atom such as a fluorine atom, a cyano group, a hydroxyl group, a carboxyl group, an alkoxy group, an alkoxycarbonyl group, etc., for example, a trifluoromethyl group, Pentafluoroethyl group, heptafluoropropyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, cyanomethyl group, cyanoethyl group, cyanopropyl group, methoxymethyl group, methoxyethyl group, ethoxymethyl group, ethoxyethyl group, or A group represented by the general formula (F1) can be given. The alkyl group represented by R ₁₃ ′ to R ₁₆ ′ is more preferably a group represented by the following general formula (F1).

In general formula (F1),
R _{50 to} R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
Rx represents a hydrogen atom or an organic group (preferably an acid-decomposable protecting group, an alkyl group, a cycloalkyl group, an acyl group, or an alkoxycarbonyl group).

Examples of the alkyl group represented by R _{50 to} R ₅₅ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and a t-butyl group. The alkyl group may be substituted, and examples of the substituent include a halogen atom such as a fluorine atom and a cyano group.
R _{50 to} R ₅₅ are preferably alkyl groups having 1 to 3 carbon atoms such as a methyl group and a trifluoromethyl group.
R _{50 to} R ₅₅ are preferably all fluorine atoms.

  As the organic group represented by Rx, an acid-decomposable protective group, which may have a substituent, an alkyl group, a cycloalkyl group, an acyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkoxycarbonylmethyl group, an alkoxymethyl group , 1-alkoxyethyl group is preferable.

The cycloalkyl group represented by R ₁₃ ′ to R ₁₆ ′ is preferably a cycloalkyl group having 3 to 20 carbon atoms, such as a cyclopentyl group, a cyclohexyl group, a norbornyl group, a tricyclodecanyl group, an adamantyl group, and the like. Is mentioned.

As the alkoxy group represented by R ₁₃ ′ to R ₁₆ ′, an alkoxy group having 1 to 8 carbon atoms is preferable, and specific examples include a methoxy group, an ethoxy group, an n-butoxy group, and a tert-butoxy group. Can do. Some or all of the hydrogen atoms of the alkoxy group may be substituted with a halogen atom such as a fluorine atom, a cyano group, a hydroxyl group, or an alkoxy group.

The alkoxycarbonyl group represented by R ₁₃ '~R _16', preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, a methoxycarbonyl group, an ethoxycarbonyl group, etc. tert- butoxycarbonyl group. Some or all of the hydrogen atoms of the alkoxycarbonyl group may be substituted with a halogen atom such as a fluorine atom, a cyano group, a hydroxyl group, or an alkoxy group.

As the alkylcarbonyl group for R ₁₃ ′ to R ₁₆ ′, an alkylcarbonyl group having 2 to 20 carbon atoms is preferable, and examples thereof include a methylcarbonyl group and an ethylcarbonyl group. Some or all of the hydrogen atoms of the alkylcarbonyl group may be substituted with a halogen atom such as a fluorine atom, a cyano group, a hydroxyl group, or an alkoxy group.

The group having a lactone structure represented by R ₁₃ ′ to R ₁₆ ′ is preferably a group containing a 5- to 7-membered ring lactone structure, and forms a bicyclo structure or a spiro structure in the 5- to 7-membered ring lactone structure. More preferably, the other ring structure is condensed.

  Specific examples of the repeating unit represented by the general formula (nI) or the general formula (nII) include the following specific examples, but the present invention is not limited to these compounds.

Resin that has a polycyclic alicyclic hydrocarbon structure, increases its solubility in an alkaline developer by the action of an acid, and decreases its solubility in an organic solvent (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) Is preferably a resin containing at least one selected from the group of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (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 ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R _{12 to} R ₁₄ , or any 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.

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, a hydrogen atom of a sulfonic acid group is substituted with a structure represented by general formulas (pI) to (pV).

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pV) which is a repeating unit having an acid-decomposable group, the 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 is 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 group of two or more groups selected from the group consisting of a ureylene group. Represents. A single bond is preferable.
Rp ₁ represents any group of the above formulas (pI) to (pV).

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

Hereinafter, although the specific example of the repeating unit which has an acid-decomposable group is shown, this invention is not limited to this.

  In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the group decomposed by the action of an acid has a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). It can be contained in at least one type of repeating unit among the repeating units having, the repeating units represented by the general formulas (nI) and (nII), and the repeating units of the copolymerization component described below. The group capable of decomposing by the action of an acid is included in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formula (pI) to general formula (pV) or general formula (nI) or (nII). Is preferred.

  The alicyclic hydrocarbon-based acid-decomposable resin 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 (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are groups represented by general formulas (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), By using a specific lactone structure, line edge roughness and 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. n2 represents an integer of 0 to 4. When n2 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.

  Examples of the repeating unit having a group having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AI). .

In general formula (AI),
Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Rb ₀ is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.
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, a carboxyl group, or a divalent group obtained by combining these. To express. A linking group represented by a single bond or —Ab ₁ —CO ₂ — is preferable. Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene 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.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a repeating unit containing an organic group having a polar group, particularly a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. preferable. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. The polar group is preferably a hydroxyl group or a cyano group.
As the alicyclic hydrocarbon structure substituted with a polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

In general formulas (VIIa) to (VIIc),
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 rest are hydrogen atoms.
In general formula (VIIa), it is more preferable that two members out of R _{2c to} R _4c are a hydroxyl group and the remaining is a hydrogen atom.

  Examples of the repeating unit having groups represented by general formulas (VIIa) to (VIId) include the repeating units represented by the following general formulas (AIIa) to (AIId).

In general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
R _2c to R _4c have the same meanings as R _2c to R _4c in formulas (VIIa) ~ (VIIc).

  Although the specific example of the repeating unit which has a structure represented by general formula (AIIa)-(AIId) is given to the following, this invention is not limited to these.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may have a repeating unit represented by the following general formula (VIII).

In the above 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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. 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. Either a repeating unit that is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain at the time of polymerization, and the linking group is a monocyclic or polycyclic hydrocarbon. You may have a structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may further contain a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and cyclohexyl (meth) acrylate.

  The resin of component (A) may further have a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. This can reduce elution of low molecular components from the resist film to the immersion liquid during immersion exposure, and is advantageous in terms of dry etching resistance. An example of such a repeating unit is a repeating unit represented by the following general formula (IX).

In general formula (IX), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. Specific examples of Ra include H, CH ₃ , CH ₂ OH, and CF ₃ .

The cyclic structure possessed by R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include cycloalkenyl having 3 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like, and cycloalkyl groups having 3 to 12 carbon atoms and cyclohexenyl group. Groups. Preferable monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferable examples include a cyclopentyl group and a cyclohexyl group.

The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group, and examples of the ring assembly hydrocarbon group include a bicyclohexyl group and a perhydronaphthalenyl group. As the bridged cyclic hydrocarbon ring, for example, bicyclic such as pinane, bornane, norpinane, norbornane, bicyclooctane ring (bicyclo [2.2.2] octane ring, bicyclo [3.2.1] octane ring, etc.) Hydrocarbon ring and homobredan, adamantane, tricyclo [5.2
. ^1.02,6 ] decane, tricyclic hydrocarbon ring such as tricyclo [4.3.1.1 ^2,5 ] undecane ring, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, and tetracyclic hydrocarbon rings such as perhydro-1,4-methano-5,8-methanonaphthalene ring. The bridged cyclic hydrocarbon ring includes a condensed cyclic hydrocarbon ring such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydroindene. A condensed ring in which a plurality of 5- to 8-membered cycloalkane rings such as a phenalene ring are condensed is also included.

Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo [5,2,1,0 ^2,6 ] decanyl group, and the like. More preferable examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

  These alicyclic hydrocarbon groups may have a substituent, and preferred substituents include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino group protected with a protecting group, and the like. It is done. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and the substituent which may further have a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino protected with a protecting group The group can be mentioned.

  Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups. 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl groups, etc., aliphatic acyl groups having 1 to 6 carbon atoms, alkoxycarbonyl Examples of the group include an alkoxycarbonyl group having 1 to 4 carbon atoms.

The content of the repeating unit represented by the general formula (IX) having neither a hydroxyl group nor a cyano group is preferably from 0 to 20 mol%, more preferably based on all repeating units in the resin (A). 0 to 10 mol%.
Specific examples of the repeating unit represented by the general formula (IX) are shown below, but the present invention is not limited thereto.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. Various repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

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

Thereby, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition temperature),
(3) Solubility in positive developer and negative developer,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

  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 alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

In the alicyclic hydrocarbon-based acid-decomposable resin of the present invention, the content of the repeating unit represented by the general formula (nI) or (nII) is preferably 5 to 50 mol%, more preferably 5 It is -30 mol%, More preferably, it is 10-30 mol%.
Particularly preferably, the repeating unit represented by the general formula (nI) or (nII) is 5 to 50 mol% and the (meth) acrylate having an acid-decomposable group represented by the general formulas (pI) to (pV). 10 to 60 mol% of the system repeating unit, 10 to 50 mol% of the (meth) acrylate repeating unit having a lactone group, 0 to 30% of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group, an acid It is a copolymer containing 0 to 20 mol% of repeating units that do not exhibit degradability.

  The acid-decomposable 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, 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, the generation of particles during storage 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 60-100 ° C.
For purification, the same method as that for the resin (D) described later can be used, and a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water washing and an appropriate solvent, only those having a specific molecular weight or less. A purification method in a solution state such as ultrafiltration to extract and remove the residual monomer by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent, A usual method such as a purification method in a solid state, such as washing the filtered resin slurry with a poor solvent, can be applied.

The weight average molecular weight of the acid-decomposable resin (A) according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, most preferably as a polystyrene-converted value by the GPC method. Is 5,000 to 15,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, or viscosity is increased and film forming property is deteriorated. Can be prevented.
Another particularly preferable form of the weight average molecular weight of the acid-decomposable resin (A) according to the present invention is 3,000 to 9,500 in terms of polystyrene by GPC method. By setting the weight average molecular weight to 3,000 to 9,500, resist residues (hereinafter also referred to as “scum”) are particularly suppressed, and a better pattern can be formed.
The degree of dispersion (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, particularly preferably 1.2 to 2.0. . The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.

In the negative developing resist composition of the present invention, the blending amount of all the acid-decomposable resins (A) according to the present invention in the whole composition is preferably 50 to 99.9% by mass in the total solid content, more Preferably it is 60-99.0 mass%.
In the present invention, the resins may be used alone or in combination.

  By using the negative developing resist composition of the present invention, in pattern formation by negative development using a negative developer (preferably an organic solvent), the pattern collapse performance is good and the trench pattern is solved. A pattern excellent in image quality can be obtained. The reason is not clear, but by containing the repeating unit represented by the general formula (nI) or the general formula (nII), the swelling of the resist film is suppressed in the negative development process. It is presumed that this is because the development progressed more uniformly. That is, as a result of suppressing the swelling of the resist film, it is considered that the generation of stress inside the resist film due to the swelling is suppressed, so that the peeling from the substrate or the collapse of the pattern is suppressed and the pattern collapse performance is improved. . Similarly, by suppressing the swelling of the resist film, it is considered that the phenomenon that the inside of the trench pattern cannot be resolved by the bridge can be suppressed, and a finer trench pattern can be resolved. The mechanism by which the swelling is suppressed by containing the repeating unit represented by the general formula (nI) or the general formula (nII) is not clarified, but the resin is probably contained by containing the repeating unit. As a result, it is presumed that the resist film was more uniformly and smoothly dissolved in a low polarity negative developer (preferably an organic solvent), and the swelling was suppressed.

  The acid-decomposable resin (A) of the present invention preferably contains no fluorine atom or silicon atom from the viewpoint of compatibility with the resin (D).

(B) Compound that generates an acid upon irradiation with actinic rays or radiation The negative developing resist composition of the present invention is a compound that generates an acid upon irradiation with an actinic ray or radiation "photoacid generator" or "(B) component ").
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation 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.

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

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, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. Preferably, it is an organic anion containing a carbon atom.

  Preferable organic anions include organic anions represented by the following formula.

Where
Rc ₁ represents an organic group.
Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality thereof, which may be substituted, is a single bond, —O—, —CO ₂ —.
, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like. Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group. Preferred examples of the organic group for Rc ₃ , Rc ₄ , and Rc ₅ include the same organic groups as those for Rc _1, and a perfluoroalkyl group having 1 to 4 carbon atoms is most preferred.
Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group.
The organic group of Rc ₁ and Rc _{3 to} Rc ₅ is particularly preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. Further, when Rc ₃ and Rc ₄ are combined to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 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 a compound (ZI-1) described later.
), (ZI-2) and (ZI-3).

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 (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-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 R ₂₀₁
Some of to R ₂₀₃ is an aryl group with the remaining being an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. 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.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group 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 linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and particularly preferable. Is an alkyl group having 1 to 4 carbon atoms and 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.

Next, the compound (ZI-2) will be described. Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group containing no 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, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group is preferably an alkoxycarbonyl methyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cyclic 2-oxoalkyl group.
Linear as R ₂₀₁ to R _203, branched or cyclic 2-oxoalkyl group may preferably be a group having a 2-position> C = O in the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy 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.

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

In general formula (ZI-3),
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 each independently represents 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 _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. Or a linear or branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, or a linear or branched pentyl group).
The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group or 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 as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.
The cycloalkyl group as R _x and R _y may be the same as the cycloalkyl group as R _1c to R _7c. The cycloalkyl group as R _x and R _y is preferably a cyclic 2-oxoalkyl group.
Examples of the linear, branched, or cyclic 2-oxoalkyl 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 .
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 the general formulas (ZII) and (ZIII),
R ₂₀₄ to 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 may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
R ₂₀₄ to R ₂₀₇ may have a substituent. 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).

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

  As the compound that generates an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are preferable.

  The compound (B) is preferably a compound that generates an aliphatic sulfonic acid having a fluorine atom or a benzenesulfonic acid having a fluorine atom upon irradiation with actinic rays or radiation.

  The compound (B) preferably has a triphenylsulfonium structure.

  The compound (B) is preferably a triphenylsulfonium salt compound having an alkyl group or a cycloalkyl group not substituted with fluorine in the cation moiety.

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

A photo-acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the photoacid generator is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and further preferably 1 to 7%, based on the total solid content of the negative developing resist composition. % By mass.

(C) Solvent Solvents that can be used when preparing the negative developing resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate. Examples include organic solvents such as esters, alkyl alkoxypropionates, cyclic lactones having 4 to 10 carbon atoms, monoketone compounds having 4 to 10 carbon atoms, which may contain rings, alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates. Can do.

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 which may contain 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 preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone is most preferred.
The mixing ratio (mass) 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 mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.

  The solvent is preferably a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

(D) Resin having at least one of fluorine atom and silicon atom The negative developing resist composition of the present invention preferably contains a resin (D) having at least one of fluorine atom and silicon atom.
The fluorine atom or silicon atom in the resin (D) may be present in the main chain of the resin or may be substituted with a side chain.

The resin (D) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, It may have a substituent.
The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.
Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and may further have another substituent.

  Specific examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom are shown below, but the present invention is not limited thereto.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having a carbon number of 1 ~ 4). R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoroethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 1,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -CCF _{3) 2} OH is preferred.

The resin (D) is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure as a partial structure having a silicon atom.
Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear alkyl group (preferably having 1 to 20 carbon atoms), or a branched alkyl group or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. As the divalent linking group, an alkylene group, a phenylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a ureylene group is used alone or in combination of two or more groups. A combination is mentioned.
n represents an integer of 1 to 5.

  Examples of the resin (D) include resins having at least one selected from the group of repeating units represented by the following general formulas (CI) to (CV).

In the general formulas (CI) to (CV),
R _{1 to} R ₃ each independently represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. Represents a group.
W _{1 to} W ₂ represent an organic group having at least one of a fluorine atom and a silicon atom.
R _{4 to} R ₇ are each independently a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. Represents a group. However, at least one of R _{4 to} R ₇ represents a fluorine atom. R ₄ and R ₅ or R ₆ and R ₇ may form a ring.
R ₈ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.
R ₉ represents a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms.
L < ₁ > -L < ₂ > represents a single bond or a bivalent coupling group, and is the same as said L < ₃ > -L < ₅ >.
Q represents a monocyclic or polycyclic cyclic aliphatic group. That is, it represents an atomic group that contains two bonded carbon atoms (C—C) and forms an alicyclic structure.
R ₃₀ and R ₃₁ each independently represents a hydrogen atom or a fluorine atom.
R ₃₂ and R ₃₃ each independently represents an alkyl group, a cycloalkyl group, a fluorinated alkyl group or a fluorinated cycloalkyl group.
However, the repeating unit represented by formula (CV) has at least one fluorine atom in at least one of R ₃₀ , R ₃₁ , R ₃₂ and R ₃₃ .

  The resin (D) preferably has a repeating unit represented by the general formula (CI), and further has a repeating unit represented by the following general formulas (C-Ia) to (C-Id). preferable.

In the general formulas (C-Ia) to (C-Id),
R ₁₀ and R ₁₁ represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms.
W _{3 to} W ₆ represent an organic group having at least one of a fluorine atom and a silicon atom.

When W _{1 to} W ₆ are organic groups having a fluorine atom, they are fluorinated, straight chain, branched alkyl group or cycloalkyl group having 1 to 20 carbon atoms, or fluorinated having 1 to 20 carbon atoms. It is preferably a linear, branched, or cyclic alkyl ether group.

Examples of the fluorinated alkyl group for W _{1 to} W ₆ include trifluoroethyl group, pentafluoropropyl group, hexafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, heptafluorobutyl group, heptafluoroisopropyl group, octafluoro Examples thereof include an isobutyl group, a nonafluorohexyl group, a nonafluoro-t-butyl group, a perfluoroisopentyl group, a perfluorooctyl group, and a perfluoro (trimethyl) hexyl group.

When W _{1 to} W ₆ are an organic group having a silicon atom, an alkylsilyl structure or a cyclic siloxane structure is preferable. Specific examples include groups represented by the general formulas (CS-1) to (CS-3).

Specific examples of the repeating unit represented by the general formula (CI) are shown below. X represents a hydrogen atom, —CH ₃ , —F, or —CF ₃ .

The resin (D) is preferably any resin selected from the following (D-1) to (D-6).
(D-1) A resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), more preferably a resin having only a repeating unit (a).
(D-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, more preferably a resin having only a repeating unit (b).
(D-3) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 carbon atoms) To 20), a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms). More preferably, a copolymer resin of the repeating unit (a) and the repeating unit (c).
(D-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 to 20 carbon atoms), Resin having a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms) More preferably, a copolymer resin of the repeating unit (b) and the repeating unit (c).
(D-5) A resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms) and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, more preferably a repeating unit Copolymer resin of unit (a) and repeating unit (b).
(D-6) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a branched alkyl group (preferably Is a C4-20), cycloalkyl group (preferably C4-20), branched alkenyl group (preferably C4-20), cycloalkenyl group, preferably C4-20) or aryl group A resin having a repeating unit (p) preferably having 4 to 20 carbon atoms, more preferably a copolymer resin of repeating unit (a), repeating unit (b) and repeating unit (c).
Repeating unit (c) having a branched alkyl group, cycloalkyl group, branched alkenyl group, cycloalkenyl group, or aryl group in resins (D-3), (D-4), and (D-6) In consideration of hydrophilicity / hydrophobicity, interaction, etc., appropriate functional groups can be introduced, but from the viewpoint of immersion liquid follow-up and receding contact angle, functional groups that do not have polar groups Is preferred.
In the resins (D-3), (D-4), and (D-6), the repeating unit (a) having a fluoroalkyl group and / or the repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure is It is preferable that it is 20-99 mol%.

  The resin (D) is preferably a resin having a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In general formula (Ia), the alkyl group in which at least one hydrogen atom of Rf is substituted with a fluorine atom preferably has 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.
The alkyl group for R ₁ is preferably a linear or branched alkyl group having 3 to 10 carbon atoms,
A branched alkyl group having 3 to 10 carbon atoms is more preferable.
R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and 3 to 1 carbon atoms.
A linear or branched alkyl group of 0 is more preferable.

  Hereinafter, although the specific example of the repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

  The repeating unit represented by the general formula (Ia) can be formed by polymerizing a compound represented by the following general formula (I).

In general formula (I),
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In the general formula (I), Rf, R ₁ and R ₂ are in the general formula (Ia), Rf, R ₁ and R ₂ synonymous.
The compound represented by the general formula (I) is a novel compound.
As the compound represented by the general formula (I), a commercially available product may be used, or a synthesized product may be used. In the case of synthesis, 2-trifluoromethylmethacrylic acid can be obtained by acidification and then esterification.

  The resin (D) having a repeating unit represented by the general formula (Ia) preferably further has a repeating unit represented by the following general formula (III).

In general formula (III):
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.

In general formula (III), the alkyl group represented by R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The trialkylsilyl group is preferably a trialkylsilyl group having 3 to 20 carbon atoms.
The group having a cyclic siloxane structure is preferably a group having a cyclic siloxane structure having 3 to 20 carbon atoms.
The divalent linking group of L ₆ is preferably an alkylene group (preferably having 1 to 5 carbon atoms) or an oxy group.

  Hereinafter, although the specific example of resin (D) which has a repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

  The resin (D) is preferably a resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III).

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, or a group formed by combining two or more thereof.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, a group having a cyclic siloxane structure, or a group formed by combining two or more thereof.
The alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, and trialkylsilyl group of R ₃ and R ₄ can introduce a functional group, but have a polar group from the viewpoint of immersion liquid followability. The functional group is preferably not substituted, and more preferably unsubstituted.
L ₆ represents a single bond or a divalent linking group.
0 <m <100.
0 <n <100.

Rf in the general formula (II) is the same as Rf in the general formula (Ia).
The alkyl group represented by R ₃ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
L ₆ is preferably a single bond, a methylene group, an ethylene group or an ether group.
m = 30 to 70 and n = 30 to 70 are preferable, and m = 40 to 60 and n = 40 to 60 are more preferable.

  Hereinafter, specific examples of the resin (D) having the repeating unit represented by the general formula (II) and the repeating unit represented by the general formula (III) will be described, but the present invention is not limited thereto. .

  Resin (D) may have a repeating unit represented by the following general formula (VIII).

In general formula (VIII):
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, an alkyl group, or —O
It represents an SO ₂ -R _42. R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. R ₄₁
And the alkyl group of R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  The resin (D) is preferably solid at room temperature (25 ° C.). Furthermore, it is preferable that glass transition temperature (Tg) is 50-200 degreeC, and 80-160 degreeC is more preferable.

Being solid at 25 ° C. means that the melting point is 25 ° C. or higher.
The glass transition temperature (Tg) can be measured by differential scanning calorimeter. For example, the specific volume changed when the sample was heated once, cooled and then heated again at 5 ° C./min. It can be measured by analyzing the value.

  The resin (D) is preferably stable to an acid and insoluble in an alkaline developer.

Resin (D) is decomposed by the action of (x) an alkali-soluble group, (y) an alkali (alkaline developer), a group that increases the solubility in the alkali developer and (z) an acid, From the viewpoint of the followability of the immersion liquid, it is preferable not to have a group that increases the solubility in the developer.
The total amount of repeating units having an alkali-soluble group in the resin (D) or a group whose solubility in a developer is increased by the action of an acid or an alkali is preferably 20 with respect to all the repeating units constituting the resin (D). It is not more than mol%, more preferably 0 to 10 mol%, still more preferably 0 to 5 mol%.
In addition, unlike the surfactant generally used in resists, the resin (D) does not have an ionic bond or a hydrophilic group such as a (poly (oxyalkylene)) group. When the resin (D) contains a hydrophilic polar group, the followability of immersion water tends to decrease, and therefore it is more preferable that the resin (D) does not have a polar group selected from a hydroxyl group, an alkylene glycol, and a sulfone group. . In addition, it is preferable not to have an ether group bonded to a carbon atom of the main chain through a linking group because hydrophilicity increases and immersion liquid followability deteriorates. On the other hand, an ether group directly bonded to a carbon atom of the main chain as shown in the general formula (III) is preferable because it may express a hydrophobic group.

  (X) Examples of alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, and (alkylsulfonyl). ) (Alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris ( And a group having an alkylsulfonyl) methylene group.

  (Y) Examples of the group that decomposes by the action of an alkali (alkaline developer) and increases the solubility in the alkali developer include a lactone group, an ester group, a sulfonamide group, an acid anhydride, and an acid imide group. Can be mentioned.

  (Z) Examples of the group that decomposes by the action of an acid and increases the solubility in a developer include the same groups as the acid-decomposable groups in the acid-decomposable resin (A).

  However, the repeating unit represented by the following general formula (pA-C) has no or very little decomposability due to the action of acid as compared with the acid-decomposable group of the resin (A), and is substantially non-acid-decomposable. Considered equivalent to gender.

In the general formula (pA-c),
Rp ₂ represents a hydrocarbon group having a tertiary carbon atom bonded to the oxygen atom in the formula.

  When the resin (D) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass and more preferably 2 to 30% by mass with respect to the molecular weight of the resin (D). Moreover, it is preferable that the repeating unit containing a silicon atom is 10-100 mass% in resin (D), and it is more preferable that it is 20-100 mass%.

  When resin (D) has a fluorine atom, the fluorine atom content is preferably 5 to 80% by mass and more preferably 10 to 80% by mass with respect to the molecular weight of resin (D). Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in resin (D), and it is more preferable that it is 30-100 mass%.

  The weight average molecular weight in terms of standard polystyrene of the resin (D) is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, still more preferably 2,000 to 15,000, and particularly preferably. Is 3,000 to 15,000.

  The resin (D) preferably has a residual monomer amount of 0 to 10% by mass, more preferably 0 to 5% by mass, and still more preferably 0 to 1% by mass. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1 in terms of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is in the range of ~ 1.5.

The addition amount of the resin (D) in the negative developing resist composition is preferably 0.1 to 20% by mass, based on the total solid content of the resist composition, and preferably 0.1 to 10% by mass. More preferably. Furthermore, it is preferable that it is 0.1-5 mass%, More preferably, it is 0.2-3.0 mass%, More preferably, it is 0.3-2.0 mass%.

  Resin (D), like acid-decomposable resin (A), naturally has few impurities such as metals, but the residual monomer and oligomer components are not more than predetermined values, for example, 0.1% by mass by HPLC. It is preferable that not only the sensitivity, resolution, process stability, pattern shape and the like as a resist can be further improved, but also a resist having no change over time such as foreign matter in liquid or sensitivity can be obtained.

  As the resin (D), various commercially available products can be used, or they 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, 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, the generation of particles during storage 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 initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (
2-methylpropionate). A chain transfer agent can also be used as needed. The density | concentration of reaction is 5-50 mass% normally, Preferably it is 20-50 mass%, More preferably, it is 30-50 mass%. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

  After completion of the reaction, the mixture is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer. For example, hydrocarbon (pentane, hexane, Aliphatic hydrocarbons such as heptane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.) Halogenated aliphatic hydrocarbons; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, benzonitrile, etc.), ethers (diethyl ether, diisopropyl ether, dimethoxyethane) Chain A Cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), alcohols ( (Methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), water, a mixed solvent containing these solvents, etc. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable. In such a solvent containing at least hydrocarbon, the ratio of alcohol (particularly methanol) and other solvent (for example, ester such as ethyl acetate, ethers such as tetrahydrofuran) is, for example, the former / the latter (volume ratio). 25 ° C.) = 10/90 to 99/1, preferably the former / the latter (volume ratio; 25 ° C.) = 30/70 to 98/2, more preferably the former / the latter (volume ratio; 25 ° C.) = 50 / It is about 50 to 97/3.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The nozzle diameter at the time of supplying the polymer solution to the precipitation or reprecipitation solvent (poor solvent) is preferably 4 mmφ or less (for example, 0.2 to 4 mmφ). Moreover, the supply speed (dropping speed) of the polymer solution into the poor solvent is, for example, about 0.1 to 10 m / second, preferably about 0.3 to 5 m / second, as the linear speed.

  The precipitation or reprecipitation operation is preferably performed with stirring. As a stirring blade used for stirring, for example, a desk turbine, a fan turbine (including a paddle), a curved blade turbine, an arrow blade turbine, a fiddler type, a bull margin type, an angled blade fan turbine, a propeller, a multistage type, an anchor type (or Horseshoe type), gate type, double ribbon, screw, etc. can be used. Stirring is preferably further performed for 10 minutes or more, particularly 20 minutes or more after the supply of the polymer solution. When the stirring time is short, the monomer content in the polymer particles may not be sufficiently reduced. Further, the polymer solution and the poor solvent can be mixed and stirred using a line mixer instead of the stirring blade.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated particulate polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

The resin may be once deposited and separated, and then dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent.
That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).
The solvent used in the preparation of the resin solution A can be the same solvent as the solvent that dissolves the monomer in the polymerization reaction, and may be the same as or different from the solvent used in the polymerization reaction.

(E) Basic compound The negative developing resist composition of the present invention preferably contains (E) a basic compound in order to reduce a change in performance over time from exposure to heating.
Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably Represents a carbon number of 6 to 20, and R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring.

About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
The alkyl groups in these general formulas (A) to (E) are more preferably unsubstituted.

  Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undecar 7-ene etc. are mentioned. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  Preferred examples of the basic compound further include an amine compound having a phenoxy group and an ammonium salt compound having a phenoxy group.

As the amine compound, a primary, secondary or tertiary amine compound can be used, and an amine compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. The amine compound is more preferably a tertiary amine compound. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the amine compound has an cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 3 to 20 carbon atoms). Preferably C6-C12) may be bonded to a nitrogen atom.
The amine compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

As the ammonium salt compound, a primary, secondary, tertiary, or quaternary ammonium salt compound can be used, and an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the ammonium salt compound has a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group in addition to the alkyl group. (Preferably having 6 to 12 carbon atoms) may be bonded to a nitrogen atom.
The ammonium salt compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.
Examples of the anion of the ammonium salt compound include halogen atoms, sulfonates, borates, and phosphates. Among them, halogen atoms and sulfonates are preferable. As the halogen atom, chloride, bromide, and iodide are particularly preferable. As the sulfonate, an organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include alkyl sulfonates having 1 to 20 carbon atoms and aryl sulfonates. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, alkoxy groups, acyl groups, and aryl groups. Specific examples of the alkyl sulfonate include methane sulfonate, ethane sulfonate, butane sulfonate, hexane sulfonate, octane sulfonate, benzyl sulfonate, trifluoromethane sulfonate, pentafluoroethane sulfonate, and nonafluorobutane sulfonate. Examples of the aryl group of the aryl sulfonate include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, naphthalene ring, and anthracene ring may have a substituent, and the substituent is a linear or branched alkyl group having 1 to 6 carbon atoms,
A cycloalkyl group having 3 to 6 carbon atoms is preferred. Specific examples of the linear or branched alkyl group and cycloalkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl, cyclohexyl and the like. Examples of the other substituent include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, cyano, nitro, an acyl group, and an acyloxy group.

  The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound or ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. Etc. The substitution position of the substituent may be any of the 2-6 positions. The number of substituents may be any in the range of 1 to 5.

It is preferable to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  The amine compound having a phenoxy group is prepared by reacting a primary or secondary amine having a phenoxy group with a haloalkyl ether by heating, and then adding an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide or tetraalkylammonium. It can be obtained by extraction with an organic solvent such as ethyl acetate or chloroform. Alternatively, after reacting by heating a primary or secondary amine and a haloalkyl ether having a phenoxy group at the end, an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide, or tetraalkylammonium is added, and then ethyl acetate, It can be obtained by extraction with an organic solvent such as chloroform.

  These basic compounds are used alone or in combination of two or more.

  The usage-amount of a basic compound is 0.001-10 mass% normally based on solid content of the resist composition for negative image development, Preferably it is 0.01-5 mass%.

  The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, still more preferably 7.0 to 150.

(F) Surfactant The negative developing resist composition of the present invention preferably further comprises (F) 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 negative developing resist composition of the present invention contains the surfactant (F), 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-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62.
JP-A-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A-2002- No. 277862, U.S. Pat. The surfactants described in the specification can be mentioned, and the following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.),
Megafuck F171, F173, F176, F189, F113, F110, F177, F120, R08 (manufactured by Dainippon Ink and Chemicals), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass ( Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), Ftop EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, 352, EF801, EF802, EF601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208, 230G, 204 , Mention may be made of 208D, 212D, the fluorine-based surfactant or silicone-based surfactants such as 218D and 222D ((KK) Neos). 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, the copolymer of a monomer having a fluoroaliphatic group and a poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer, but also a monomer having two or more different fluoroaliphatic groups, 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 ₃ F ₇ group and (poly (oxy) And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

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.

  These surfactants may be used alone or in several combinations.

  (F) The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the negative developing resist composition (excluding the solvent). .

(G) Carboxylic acid onium salt The negative developing resist composition in the present invention may contain (G) a carboxylic acid onium salt. Examples of the carboxylic acid onium salt include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, the (G) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, it is preferable that the carboxylate residue of the (G) 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 (G) 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 carboxylic acid onium salt in the composition is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, and more preferably 1%, based on the total solid content of the composition. -7% by mass.

(H) Other Additives The negative resist composition of the present invention may further contain dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors and developers as necessary. A compound that promotes solubility, such as a phenol compound having a molecular weight of 1000 or less, an alicyclic group having a carboxyl group, or an aliphatic compound) can be contained.

Such a phenol compound having a molecular weight of 1000 or less is disclosed in, for example, JP-A-4-12293.
No. 8, JP-A-2-28531, U.S. Pat. No. 4,916,210, European Patent No. 219294, etc., 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.

  In the pattern formation method of the present invention, a step of forming a film of a resin composition on a substrate, which increases the solubility in a positive developer and decreases the solubility in a negative developer by irradiation with actinic rays or radiation. The step of exposing the film, the step of heating the film (also referred to as baking or PEB (post exposure bake)) and the step of developing the film positively can be performed by a generally known method.

The light source wavelength limit is not used for the exposure apparatus in the present invention, KrF excimer laser wavelength (248 nm), ArF excimer laser wavelength (193nm), F ₂ excimer laser wavelength (157 nm), EUV light (13.5 nm), etc. Applicable.

Moreover, the immersion exposure method can be applied in the step of performing exposure according to the present invention.
The immersion exposure method is a technology for filling and exposing a projection lens and a sample with a liquid having a high refractive index (hereinafter also referred to as “immersion liquid”) as a technique for increasing the resolving power.
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 resolution and the 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 a projection optical system with 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 performing immersion exposure, (1) after forming the film on the substrate, before the exposure step and / or (2) after exposing the film via the immersion liquid, You may implement the process of wash | cleaning the surface of a film | membrane with an aqueous | water-based chemical | medical solution before the process to heat.

  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 film. 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, an additive liquid that reduces the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens element.
As such an additive, for example, an aliphatic alcohol having a refractive index substantially equal to that of water is preferable, and specific examples include 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 the present invention, the substrate on which the film is formed is not particularly limited, and silicon, SiN, inorganic substrates such as SiO ₂ and SiN, coated inorganic substrates such as SOG, semiconductor manufacturing processes such as IC, liquid crystal, and thermal head For example, a substrate generally used in a circuit board manufacturing process such as the photolithographic lithography process can be used. Further, if necessary, an organic antireflection film may be formed between the film and the substrate.

  As the organic antireflection film, any one of a light absorber and an organic film made of a polymer material can be used. For example, DUV30 series, DUV-40 series, Brewer Science Co., Ltd. AR-2, AR- 3, AR-5, ARC series such as ARC29A manufactured by Nissan Chemical Industries, etc., commercially available organic antireflection films can be used. Further, as the antireflection film, an inorganic antireflection film can be used. For example, an antireflection film such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon, or the like can be used.

When performing positive development, an alkali developer is preferably used.
Examples of the alkali developer used for positive development include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine and the like. Primary amines, diethylamine, secondary amines such as di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, Alkaline aqueous solutions such as quaternary ammonium salts such as tetraethylammonium hydroxide and cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.
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.
In particular, a 2.38% aqueous solution of tetramethylammonium hydroxide is desirable.

  As the rinsing liquid in the rinsing treatment performed after the positive development, pure water can be used, and an appropriate amount of a surfactant can be added.

When performing negative development, it is preferable to use an organic developer containing an organic solvent.
As an organic developer that can be used in negative development, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used. .
In the present invention, the ketone solvent is a solvent having a ketone group in the molecule, the ester solvent is a solvent having an ester group in the molecule, and the alcohol solvent is alcoholic in the molecule. It is a solvent having a hydroxyl group, an amide solvent is a solvent having an amide group in the molecule, and an ether solvent is a solvent having an ether bond in the molecule. Among these, there is a solvent having a plurality of types of the above functional groups in one molecule, and in that case, it corresponds to any solvent type including the functional group of the solvent. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification. Further, the hydrocarbon solvent is a hydrocarbon solvent having no substituent.
Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methyl ethyl ketone. And methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, and γ-butyrolactone.
Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxy acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene group Coal monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl Cetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate , Ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate Methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and the like.
As the ester solvent, a solvent represented by general formula (1) described later or a solvent represented by general formula (2) described later is preferably used, and a solvent represented by general formula (1) is used. Is more preferable, alkyl acetate is more preferably used, and butyl acetate is most preferably used.
Examples of alcohol solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, alcohols such as n-octyl alcohol, n-decanol, 3-methoxy-1-butanol, glycol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, Triethylene glycol monoethyl ether, methoxymethylbutanol, ethylene glycol monoethyl ether, ethylene glycol Propyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, may be mentioned glycol ether solvents such as containing a hydroxyl group such as propylene glycol monomethyl ether. Among these, it is preferable to use a glycol ether solvent.
Examples of the ether solvent include, in addition to the above-described glycol ether solvent containing a hydroxyl group, a glycol ether solvent not containing a hydroxyl group such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, Anisole, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, 1,4-dioxane and the like can be mentioned. Preferably, a glycol ether solvent is used.
Examples of the amide solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like. Can be used.
Examples of the hydrocarbon solvents include aromatic hydrocarbon solvents such as toluene and xylene, pentane, hexane, octane, decane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, and perfluoro. Aliphatic hydrocarbon solvents such as hexane and perfluoroheptane, toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene And aromatic hydrocarbon solvents such as dipropylbenzene. Among these, aromatic hydrocarbon solvents are preferable.
A plurality of the above solvents may be mixed, or may be used by mixing with a solvent other than those described above or water.

  As a developer that can be used in negative development, a solvent represented by the following general formula (1) is preferably used.

In general formula (1),
R and R ′ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxyl group, an alkoxycarbonyl group, a carboxyl group, a hydroxyl group, a cyano group or a halogen atom. R and R ′ may be bonded to each other to form a ring. R and R ′ are preferably a hydrogen atom or an alkyl group, and the alkyl group of R and R ′ may be substituted with a hydroxyl group, a carbonyl group, a cyano group, or the like.

  Examples of the solvent represented by the general formula (1) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, and butyl lactate. , Propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, propion Examples include isopropyl acid, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, and the like.

  Among these, in the solvent represented by the general formula (1), R and R ′ are preferably unsubstituted alkyl groups, more preferably alkyl acetates, and particularly preferably butyl acetate.

The solvent represented by the general formula (1) may be used in combination with one or more other solvents. The combined solvent in this case is not particularly limited as long as it can be mixed without being separated into the solvent represented by the general formula (1), and the solvents represented by the general formula (1) may be used in combination. , Other ester solvents, ketone solvents, alcohol solvents, amide solvents,
You may mix and use for the solvent selected from an ether solvent and a hydrocarbon solvent. One or more solvents can be used in combination, but it is preferably one solvent in order to obtain stable performance. When mixing and using 1 type of combined solvent, the mixing ratio (mass ratio) of the solvent represented by General formula (1) and a combined solvent is 20: 80-99: 1 normally, Preferably it is 50: 50-97. : 3, more preferably 60:40 to 95: 5, and most preferably 60:40 to 90:10.

  As a developer that can be used in negative development, a solvent represented by the following general formula (2) is preferably used.

In general formula (2),
R ″ and R ″ ″ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxyl group, an alkoxycarbonyl group, a carboxyl group, a hydroxyl group, a cyano group or a halogen atom. R ″ and R ″ ″ may be bonded to each other to form a ring. R ″ and R ″ ″ are preferably a hydrogen atom or an alkyl group.
R ′ ″ represents an alkylene group or a cycloalkylene group. R ′ ″ is preferably a hydrogen atom or an alkyl group. The alkyl group that R ″, R ′ ″, and R ″ ″ have may be substituted with a hydroxyl group, a carbonyl group, a cyano group, or the like.

  In the general formula (2), the alkylene group represented by R ″ ″ may have an ether bond in the alkylene chain.

Examples of the solvent represented by the general formula (2) include propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl. Ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol model Propyl ether acetate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, ethyl methoxyacetate, ethyl ethoxyacetate, 2- Methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4- Propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl -4-methoxy-pentyl acetate, 4-methyl-4-methoxy pentyl acetate, and the like.

The solvent represented by the general formula (2) may be used in combination with one or more other solvents. The combined solvent in this case is not particularly limited as long as it can be mixed without being separated into the solvent represented by the general formula (2), and the solvents represented by the general formula (2) may be used in combination. The solvent represented by the general formula (2) may be used by mixing with a solvent selected from other ester solvents, ketone solvents, alcohol solvents, amide solvents, ether solvents and hydrocarbon solvents. good. One or more solvents can be used in combination, but it is preferably one solvent in order to obtain stable performance. When mixing and using 1 type of combined solvent, the mixing ratio (mass ratio) of the solvent represented by General formula (2) and a combined solvent is 20: 80-99: 1 normally, Preferably it is 50: 50-97. : 3, more preferably 60:40 to 95: 5, and most preferably 60:40 to 90:10.

  As the solvent used in the negative development, an organic solvent containing no halogen atom is preferably used from the viewpoint of cost reduction of the solvent used for the development. The content of the organic solvent not containing halogen atoms in the total weight of all the solvents used in the negative development is usually 60% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, Especially preferably, it is 97 mass% or more.

The boiling point of the solvent used in the negative development is desirably 50 ° C. or higher and lower than 250 ° C.
The ignition point of the solvent used in the negative development is preferably 200 ° C. or higher.

An appropriate amount of a surfactant can be added to the developer that can be used for negative development, if necessary.
The surfactant is not particularly limited, and for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. Examples of these fluorine and / or silicon surfactants 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, US Pat. No. 5,405,720, etc. The surfactants described in US Pat. Nos. 5,360,692, 5,529,881, 5,296,330, 5,346,098, 5,576,143, 5,294,511, and 5,824,451 can be mentioned. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant.
The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.

  As a negative development method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a developer is raised on the surface of the substrate by surface tension, and is developed for a certain period of time for development. Method (paddle method), Method of spraying developer on substrate surface (spray method), Method of continuing to apply developer while scanning developer application nozzle at constant speed on substrate rotating at constant speed ( Dynamic dispensing method) can be applied.

  Further, after the step of performing the negative development, a step of stopping the development may be performed while substituting with another solvent.

After the step of performing negative development, it is preferable to include a step of washing with a rinse solution containing an organic solvent.
In the washing step after negative development, a rinsing solution containing at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is usually used. Can be used.
In the present invention, the hydrocarbon solvent is a hydrocarbon solvent having no substituent. A ketone solvent is a solvent having a ketone group in the molecule, an ester solvent is a solvent having an ester group in the molecule, and an alcohol solvent is an alcoholic hydroxyl group in the molecule. The amide solvent is a solvent having an amide group in the molecule, and the ether solvent is a solvent having an ether bond in the molecule. Among these, there are also solvents having a plurality of the above functional groups in one molecule, in which case,
It shall correspond to any solvent type containing the functional group which the solvent has. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification.
For example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone , Ketone solvents such as acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, propylene glycol Monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether Esters such as teracetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate System solvents can be used.
Examples of alcohol solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n- Alcohols such as octyl alcohol and n-decanol, glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol mono Examples include glycol ether solvents such as ethyl ether and methoxymethylbutanol.
Examples of the ether solvent include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.
As the amide solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone, etc. can be used. .
Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, octane and decane.

  The rinsing liquid containing an organic solvent preferably uses at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents. More preferably, at least one solvent selected from alcohol solvents and ester solvents can be used as the rinsing liquid. Most preferably, a rinsing liquid containing a monohydric alcohol having 6 to 8 carbon atoms can be used as the rinsing liquid. Here, examples of the monohydric alcohol having 6 to 8 carbon atoms contained in the rinse liquid used in the washing step after the negative development include linear, branched, and cyclic monohydric alcohols. 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol, and the like can be used. Preferably, they are 1-hexanol, 2-heptanol, and 2-hexanol. More preferably, it is 1-hexanol or 2-hexanol.

A plurality of the above solvents may be mixed, or may be used by mixing with an organic solvent other than the above.
The solvent may be mixed with water, but the water content in the rinsing liquid is usually 30% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 3% by mass or less. is there. By setting the water content to 30% by mass or less, good development characteristics can be obtained.

An appropriate amount of a surfactant can be added to the rinsing liquid as necessary.
The surfactant is not particularly limited, and for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.
The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.

  In the step of cleaning with the rinse solution, the resist after the negative development is cleaned with the rinse solution containing the organic solvent. The method of the cleaning treatment is not particularly limited. For example, a method of continuously applying the rinse liquid onto the substrate rotating at a constant speed (rotary coating method), or immersing the substrate in a tank filled with the rinse liquid for a certain period of time. A method (dip method), a method of spraying a rinsing liquid onto the substrate surface (spray method), and the like can be applied.

In addition, after the developing process or the rinsing process, a process of removing the developing solution or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.
Furthermore, after the development processing, the rinsing processing or the processing with the supercritical fluid, a heat processing can be performed in order to remove the solvent remaining in the pattern. The heating temperature is not particularly limited as long as a good resist pattern can be obtained, and is usually 40 ° C to 160 ° C. The heat treatment may be performed a plurality of times.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

Synthesis Example 1 (Synthesis of Resin (A1))
Under a nitrogen stream, 20 g of tetrahydrofuran was placed in a three-necked flask and heated to 80 ° C. The following Monomer-A, Monomer-B, and Monomer-C were dissolved in tetrahydrofuran at a molar ratio of 40/50/10 to prepare a 22 mass% monomer solution (solvent 1) (200 g). Furthermore, a solution containing initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to (solvent 1) so as to be 6 mol% with respect to the monomer. After completion of the dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then poured into a mixed solution of 1400 ml of hexane / 600 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 37 g of Resin (A1). The obtained resin (A1) had a weight average molecular weight of 9000 and a dispersity (Mw / Mn) of 1.9.

  Other resins (A2) to (A16) and comparative resins (R1) to (R2) were also synthesized using the same method. The weight average molecular weight was adjusted by changing the amount of the polymerization initiator.

  In Table 1 below, for the resins (A1) to (A16) of the present invention and the resins (R1) to (R2) of Comparative Examples, the monomers used in the synthesis, the molar ratio of repeating units corresponding to the monomers, and the weight average molecular weight (Mw) and dispersity (Mw / Mn) are shown.

Negative resist composition for development (A-1)
A solution having a solid content concentration of 3.9% by mass obtained by dissolving the following components in a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) / propylene glycol monomethyl ether (PGME) (mass ratio 60/40) The mixture was filtered through a polyethylene filter having a micron pore size to prepare a negative developing resist composition (A-1).
Resin (A1) 1.83 g, triphenylsulfonium nonaflate 69.6 mg, 2,6-diisopropylaniline 8.7 mg, PF6320 (fluorine surfactant manufactured by OMNOVA) 1.7 mg.

Negative resist compositions for development (A-2) to (A-16) and (RA-1) to (RA-2)
A negative developing resist composition (A-2) to (A-16) obtained by filtering a solution having a solid content concentration of 3.9% by mass in the following Table 2 through a polyethylene filter having a pore size of 0.1 micron. (RA-1) to (RA-2) were prepared.

  The abbreviations in the table are shown below.

  [Acid generator]

[Basic compounds]
E-1: 2,6-diisopropylaniline E-2: N, N-dibutylaniline E-3: Tris (methoxyethoxy) ethylamine E-4: Triethanolamine E-5: 2-phenylbenzimidazole

〔solvent〕
SL-1: Propylene glycol monomethyl ether acetate SL-2: Propylene glycol monomethyl ether SL-3: γ-butyrolactone SL-4: Cyclohexanone SL-5: Ethyl lactate

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4: PF6320 (manufactured by OMNOVA) (fluorine-based)

Example 1
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. A negative developing resist composition (A-1) prepared thereon was applied using a spin coater, and baked at 110 ° C. for 60 seconds to form a 100 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75) at an exposure amount (optimum exposure amount) of 30 mJ / cm ² through a mask having a mask line width of 90 nm and a pitch of 180 nm. Then, after heating at 110 ° C. for 60 seconds, developed with butyl acetate (negative developer) for 30 seconds (negative development), rinsed with 1-hexanol for 30 seconds, and formed a resist pattern having a pitch of 180 nm and a trench line width of 60 nm. Obtained.

Examples 2-16 and Comparative Examples 1-2
Using the resist compositions (A-2) to (A-16) and (RA-1) to (RA-2), respectively, in the same manner as in the method of Example 1, the optimum exposure amount of each resist composition is obtained. Thus, a resist pattern having a pitch of 180 nm and a trench line width of 60 nm was obtained.

Example 17
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. A negative developing resist composition (A-1) prepared thereon was applied using a spin coater, and baked at 100 ° C. for 80 seconds to form a 100 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75) at an exposure amount (optimum exposure amount) of 23 mJ / cm ² through a mask having a mask line width of 180 nm and a pitch of 360 nm. After heating at 105 ° C. for 60 seconds, development with butyl acetate (negative developer) for 30 seconds (negative development), followed by rinsing with 1-hexanol for 30 seconds, a pattern with a pitch of 360 nm and a line width of 90 nm Got. Next, development is performed with a tetramethylammonium hydroxide aqueous solution (0.02% by mass) (positive developer) for 30 seconds (positive development), and rinsed with pure water for 30 seconds, so that the pitch is 180 nm and the line width is 90 nm. A line and space pattern was obtained.

Comparative Example 3
An organic antireflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) is applied on a silicon wafer.
Baking was carried out at 60 ° C. for 60 seconds to form a 78 nm antireflection film. A negative developing resist composition (A-16) prepared thereon was applied using a spin coater and baked at 100 ° C. for 80 seconds to form a 100 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75) at an exposure amount (optimum exposure amount) of 10 mJ / cm ² through a mask having a mask line width of 90 nm and a pitch of 180 nm. Thereafter, the mixture was heated at 105 ° C. for 60 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) (positive developer) for 30 seconds (positive development), and rinsed with pure water for 30 seconds. . As a result, a resist pattern having a pitch of 180 nm and a trench line width of 60 nm could not be obtained.

<Evaluation of pattern collapse>
When the exposure amount for forming a pattern having a pitch of 180 nm and a trench line width of 60 nm is an optimum exposure amount with respect to the patterns obtained in Examples 1 to 16 and Comparative Examples 1 and 2, and negative development is performed ( In Examples 1 to 16 and Comparative Examples 1 and 2), when the exposure amount is made smaller than the optimum exposure amount, the dimensions of the resist pattern are reduced. On the other hand, when positive development is performed (Comparative Example) 3) The size of the resist pattern is reduced by increasing the exposure amount more than the optimum exposure amount, and the resist pattern is resolved without being peeled off from the substrate, broken in the middle of the pattern, or collapsed. The line width was determined and used as the pattern collapse line width. A smaller value indicates that a finer pattern is resolved without falling, indicating that the pattern falling performance is better. The results are shown in Table 3.

<Evaluation of trench pattern resolution>
With respect to the patterns obtained in Examples 1 to 16 and Comparative Examples 1 and 2, the mask line width and pitch were determined by changing the mask line width and pitch in the mask line width and pitch in the exposure amount for forming a resist pattern having a pitch of 180 nm and a trench line width of 60 nm. The mask pattern width was reduced successively while maintaining the space ratio of 1: 1, and the limit mask line width at which the trench pattern was resolved without bridging was defined as the trench pattern resolution line width. The smaller this value, the finer the trench pattern is resolved, and the better the trench pattern resolution is. The results are shown in Table 3.

  From the above examples, it is clear that the negative developing resist composition of the present invention has a good pattern collapse performance in the negative developing process and is excellent in the resolution of the trench pattern. . Further, it is apparent that the negative developing resist composition of the present invention can resolve a pattern even in a multiple developing process using both a negative developing process and a positive developing process.

It is a schematic diagram showing the relationship between the positive development, the negative development and the exposure amount in the conventional method. It is a schematic diagram showing a pattern forming method using both positive development and negative development in the method of the present invention. It is a schematic diagram which shows the relationship between positive image development, negative image development, and exposure amount.

Explanation of symbols

1 Irradiation light 2 Exposure mask 3 Pattern 4 Wafer

Claims (3)

(A) Resin containing a repeating unit represented by general formula (nI) or general formula (nII) and having reduced solubility in a negative developer by the action of an acid, (B) a photoacid generator, and (C) A negative resist composition containing a solvent.

In general formula (nI) and general formula (nII),
R ₁₃ ′ to R ₁₆ ′ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or a lactone structure. Represents a group.
X ₁ and X ₂ each independently represent a methylene group, an ethylene group, an oxygen atom or a sulfur atom.
n represents an integer of 0 to 2. (A) (A) a resin containing a repeating unit represented by general formula (nI) or general formula (nII) and having reduced solubility in a negative developer by the action of an acid, (B) a photoacid generator, and (C) A step of applying a negative resist composition containing a solvent,
(A) exposure process,
(D) A pattern forming method comprising a step of developing using a negative developer.

In general formula (nI) and general formula (nII),
R ₁₃ ′ to R ₁₆ ′ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or a lactone structure. Represents a group.
X ₁ and X ₂ each independently represent a methylene group, an ethylene group, an oxygen atom or a sulfur atom.
n represents an integer of 0 to 2.   The pattern forming method according to claim 2, further comprising: (c) a step of developing using a positive developer.

Images