JP2009025708A - Pattern formation method - Google Patents

Abstract

[PROBLEMS] To stably form a high-precision fine pattern for manufacturing a highly integrated and high-precision electronic device, and having high sensitivity, excellent trench pattern resolution, and good density dependency. A pattern forming method for forming a simple pattern is provided.
(A) a step of applying a negative resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developer is decreased; (a) an exposure step; and (c) The pattern formation method including the process of developing using the negative developing solution containing the organic solvent whose content of a metal impurity is 100 ppb or less.
[Selection figure] None

Description

  The present invention relates to a pattern forming method used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and a lithography process for other photo applications. In particular, a pattern forming method using a negative developing resist composition and a negative developing solution, which is suitable for exposure with an ArF exposure apparatus and an immersion projection exposure apparatus using far ultraviolet light having a wavelength of 193 nm as a light source It is about.

  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.

  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 (Japanese Patent Laid-Open No. 2006-156422) and the like. Recent progress in double exposure technology includes Non-Patent Document 1 (SPIE Proc 5754, 1508 (2005)), Non-Patent Document 2 (SPIE Proc 5377, 1315 (2004)), Non-Patent Document 3 (SPIE Proc 61531K-1 ( 2006)).

  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 a large exposure margin and depth of focus cannot be obtained.

On the other hand, a double development technique as a double patterning technique for increasing the resolving power is described in Japanese Patent Application Laid-Open No. 2000-199953. 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, when a fine pattern is formed 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.

  In order to form a fine pattern, it is a matter of course that the pattern resolution is excellent. However, in order to shorten the wafer processing time, it is required to form a pattern with high sensitivity. At this time, as sensitivity increases, not only the resolution but also the density dependency may decrease, and development of a resist that satisfies these characteristics is strongly desired. Here, the density dependency means a pattern dimension difference between a portion where the resist pattern density is high and a portion where the resist pattern density is low. If this difference is large, the process margin becomes narrow during actual pattern formation. One of the important issues in resist technology development is how to reduce the size. High sensitivity, high resolution, and good density dependence are in a trade-off relationship, and it is very important how to satisfy these simultaneously.

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 3 (Japanese Patent Laid-Open No. 2001-215731) discloses an exposed portion of a resist material containing a copolymer of a styrene monomer and an acrylic monomer. A developer containing an aliphatic linear ether solvent or aromatic ether solvent for dissolving and developing and a ketone solvent having 5 or more carbon atoms is described. Patent Document 4 (Japanese Patent Application Laid-Open No. 2006-227174) discloses an acetic acid group or a ketone group for dissolving and developing an exposed portion of a resist material that has a polymer chain that is broken by irradiation with radiation. And a developer having at least two ether groups and phenyl groups and having a molecular weight of 150 or more. Further, Patent Document 5 (Japanese Patent Application Laid-Open No. 6-194847) discloses an unexposed resist material mainly composed of a photosensitive polyhydroxyether resin obtained by a reaction between a polyhydroxyether resin and glycidyl (meth) acrylate. Described is 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 for developing a portion. Yes.

  However, in reality, it is extremely difficult to find a combination of a resist composition, a developing solution, a rinsing solution, and the like that simultaneously satisfy high sensitivity, high resolution, and good density dependence. In the case of developing the negative type used and forming a fine pattern with a line width of 100 nm or less, no combination has been found that simultaneously satisfies high sensitivity, high resolution, and good density dependence. is the current situation.

In addition, in the combination of the resist composition and the developer described above, a specific resist composition is
It only provides a system for forming a pattern in combination with a highly polar alkaline developer or a developer containing a low polarity organic solvent. 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. .
The use of fine pattern formation by double development combining a positive developer and a negative developer is preferable because a pattern with higher resolution can be formed, but it can also be suitably applied to pattern formation by double development. At present, a combination of a resist composition, a negative developer, and a positive developer that simultaneously satisfies high resolution, high sensitivity, and good density dependency is not yet known.
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 shown by the solid line in FIG. 1. The negative developer is lower than the predetermined threshold. 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.

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

  The present invention solves the above problems and stably forms a high-precision fine pattern for manufacturing a highly integrated and high-precision electronic device. Therefore, the present invention has high sensitivity and excellent trench pattern resolution. It is another object of the present invention to provide a pattern forming method for forming a pattern having good density dependency.

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

(1) (a) a step of applying a negative developing resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developing solution decreases;
(A) an exposure step; and (c) a pattern forming method comprising: developing with a negative developer containing an organic solvent having a metal impurity content of 100 ppb or less.

  (2) (c) The step of developing using a negative developer comprises developing using a negative developer containing an organic solvent having a sodium content of 50 ppb or less. The pattern formation method as described.

(3) (c) The step of developing using a negative developer is performed using a negative developer containing an organic solvent having an iron content of 20 ppb or less (1) or (2)
The pattern forming method according to 1.

  (4) (c) The step of developing using a negative developer is at least one selected from ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents and hydrocarbon solvents. The pattern forming method according to any one of (1) to (3), which is a step performed using a negative developing solution containing an organic solvent.

  (5) (c) The step of developing using a negative developer is a step of developing using a developer containing a solvent represented by the following general formula (1) (1) ) To (4).

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.

  (6) (c) The process of performing development using a negative developer is a process performed using a developer containing butyl acetate. Pattern formation method.

  (7) (c) The step of developing using a negative developer is a step of developing using a developer containing a solvent represented by the following general formula (2) (1) ) To (5).

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 ′ ″ represents an alkylene group or a cycloalkylene group.

  (8) The pattern forming method as described in any one of (1) to (7), further comprising (d) a step of developing using a positive developer.

  (9) A negative developer that is a negative developer used in the pattern forming method according to any one of (1) to (7), and that is manufactured through a step of filtering with an ion exchange filter.

  The preferred embodiments of the present invention will be further described below.

  (10) (c) After the step of developing with a negative developer, the method further comprises (e) a step of washing with a rinsing solution containing an organic solvent. The pattern formation method in any one of.

  (11) The rinsing liquid contains at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents ( The pattern formation method as described in 10).

  (12) The pattern forming method as described in (11), wherein the rinse liquid contains at least one organic solvent selected from an ester solvent and an alcohol solvent.

  (13) The pattern forming method as described in (12), wherein the rinse liquid contains a monohydric alcohol.

  (14) The rinsing solution includes (10) at least one developer component used in the step of developing with (c) a negative developer, according to any one of (10) to (13) The pattern formation method as described.

  (15) (c) The step of developing using a negative developer includes a step of supplying a negative developer onto the surface of the substrate while rotating the substrate (1) to (8) ) And the pattern forming method according to any one of (10) to (14).

  (16) (e) The step of cleaning with a rinsing liquid containing an organic solvent includes a step of supplying a rinsing liquid onto the surface of the substrate while rotating the substrate (10) to (15). The pattern formation method in any one of.

  (17) (d) The step of developing using a positive developer is at least one selected from the group consisting of primary amine compounds, secondary amine compounds, tertiary amine compounds and quaternary amine compounds. The pattern forming method as described in (8), which is a step performed using an aqueous solution containing types.

  (18) The pattern forming method as described in (17), wherein the step of developing using a positive developer is a step of using an aqueous solution of tetramethylammonium hydroxide.

  (19) The pattern forming method as described in (17) or (18), wherein the concentration of the amine compound in the positive developer is 0.01 to 20% by mass based on the total mass of the developer. .

  (20) The pattern forming method as described in any one of (8) and (17) to (19), wherein the content of the metal impurity in the positive developer is 100 ppb or less.

  (21) (d) The method according to any one of (8) and (17) to (20), further including (f) a rinsing step after the step of developing using a positive developer. Pattern forming method.

  (22) (f) The pattern forming method as described in (21), wherein the rinse liquid used in the rinse step is pure water.

  (23) The pattern forming method according to any one of (1) to (8) and (10) to (22), wherein exposure is performed using light having a wavelength of 200 nm or less.

  (24) The pattern forming method as described in any one of (1) to (8) and (10) to (23), wherein exposure is performed through an immersion medium.

  (25) The pattern forming method as described in (24), wherein the immersion medium is water.

  (26) The pattern forming method as described in any one of (1) to (8) and (10) to (25), further comprising (i) a heating step after the exposure step.

  (27) A negative resist composition is (A) a resin whose polarity is increased by the action of an acid and whose solubility in a negative developer is reduced, and (B) a compound that generates an acid upon irradiation with actinic rays or radiation. And (C) The pattern forming method according to any one of (1) to (8) and (10) to (26), which comprises a solvent.

  (28) The pattern forming method as described in (27), wherein the resin as the component (A) is a resin having an alicyclic hydrocarbon structure.

  (29) The side chain of the resin of component (A) is a resin having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) ( 27) or the pattern forming method according to (28).

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R _{12 to} R ₁₄ represents a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group 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.

  (30) The pattern forming method as described in any one of (27) to (29), wherein the resin (A) has a weight average molecular weight of 1,000 to 200,000.

  (31) The pattern forming method as described in any one of (27) to (30), wherein the resin as the component (A) is an alicyclic hydrocarbon-based acid-decomposable resin having a lactone structure.

  (32) The pattern forming method according to any one of (27) to (31), wherein the negative developing resist composition further contains a basic compound.

  (33) The pattern forming method as described in any one of (27) to (32), wherein the negative developing resist composition further contains a fluorine-based and / or silicon-based surfactant.

  (34) The pattern forming method as described in any one of (27) to (33), wherein the solvent (C) is two or more kinds of mixed solvents containing propylene glycol monomethyl ether acetate.

  (35) The negative developing resist composition further comprises a resin (D) having at least one of a fluorine atom and a silicon atom, according to any one of (27) to (34), Pattern forming method.

  (36) The pattern according to any one of (1) to (8) and (10) to (35), wherein the negative developer is produced through a step of filtering using an ion exchange filter. Forming method.

  According to the present invention, it is possible to provide a pattern forming method capable of forming a pattern with high sensitivity, good trench pattern resolution, and good density dependency.

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 and removes the exposed portion above the predetermined threshold indicated by the solid line in FIG. 1, and the negative developer selects the exposed portion below the predetermined threshold. It is a developer that is dissolved and removed. 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 in which the development process using the positive developer and the development process using the negative developer are combined. 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.

  In the present invention, as a technique suitable for pattern formation using a negative developing resist composition and a negative developer, (a) a resin whose polarity is increased by the action of an acid and whose solubility in the negative developer is reduced. A step of applying a resist composition for negative development containing, (a) an exposure step, and (c) as shown in FIG. 2, selectively exposing and dissolving the exposed portion below a predetermined threshold (b), A new pattern forming method is presented that combines a step of developing using a negative developer containing an organic solvent having a metal impurity content of 100 ppb or less.

  To carry out the present invention, (i) a negative developing resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developing solution is reduced, and (ii) the content of metal impurities is A negative developer containing an organic solvent of 100 ppb or less is required.

  In order to carry out the present invention, it is further preferable to use (iii) a positive developer (preferably an alkali developer).

  In order to carry out the present invention, it is preferable to further use (iv) a negative developing rinse solution containing an organic solvent.

The resin contained in the resist composition of the present invention is a resin that not only decreases the solubility in a negative developer by increasing the polarity by the action of an acid, but also increases the solubility in a positive developer.
Thus, the resist composition of the present invention is “a resin composition that forms a film whose solubility in a negative developing solution is reduced and the solubility in a positive developing solution is increased by irradiation with actinic rays or radiation”. Therefore, the resist composition of the present invention selectively selects a developing solution (positive developing solution) that selectively dissolves and removes an exposed portion having a predetermined threshold value (a) or higher and an exposed portion having a predetermined threshold value (b) or lower. Can be suitably used for pattern formation by multiple development in which a developer (negative developer) to be dissolved / removed in a film and a resist composition for negative developer are combined.
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.

  In the case of performing a pattern forming process using two types of developers, a positive developer and a negative developer, the order of development is not particularly limited, but after exposure, a positive developer or a negative developer It is preferable to carry out development with a negative type or positive type development using a developer different from the first development. Furthermore, after negative development, it is preferable to wash with a negative development rinse containing an organic solvent. After negative development, it is possible to form a better pattern by washing with a rinse solution containing an organic solvent.

  Hereinafter, a pattern forming method for carrying out the present invention will be described in detail.

<Pattern formation method>
The pattern forming method of the present invention comprises:
(A) A step of applying a negative developing resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developing solution decreases.
(A) an exposure step, and (c) a pattern forming method comprising: developing using a negative developer containing an organic solvent having a metal impurity content of 100 ppb or less.

  The pattern forming method of the present invention preferably further includes (e) a step of developing using a positive developer to form a resist pattern. Thereby, a pattern having a resolution twice as high as the frequency of the optical aerial image (light intensity distribution) can be formed.

  (A) The step of applying a negative developing resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developing solution is reduced is as long as the resist composition can be applied on the substrate. Any method may be used, and a conventionally known spin coating method, spray method, roller coating method, dipping method, or the like can be used. Preferably, the resist composition is applied by a spin coating method. After applying the resist composition, the substrate is heated (pre-baked) as necessary. Thereby, the film | membrane from which the insoluble residual solvent was removed can be formed uniformly. Although the temperature of prebaking is not specifically limited, 50 to 160 degreeC is preferable, More preferably, it is 60 to 140 degreeC.

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, thermal A substrate generally used in a manufacturing process of a circuit board such as a head or the lithography process of other photo applications can be used.

Before forming the resist film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as an organic antireflection film, ARC series such as DUV30 series manufactured by Brewer Science, DUV-40 series, AR-2, AR-3, AR-5 manufactured by Shipley, ARC29A manufactured by Nissan Chemical Co., etc. Commercially available organic antireflection films can also be used.

  As the resist composition, (i) a negative developing resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developing solution is reduced is necessary. Among these, those that can be used for exposure using a wavelength of 250 nm or less are preferable, and those that can be used for exposure using a wavelength of 200 nm or less are more preferable. Examples thereof include the components described later in “Negative developer resist composition”.

(A) In the exposure step, the resist film can be exposed by a generally well-known method. Preferably, the resist film is irradiated with actinic rays or radiation through an immersion liquid through a predetermined mask. Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally.
Although there is no restriction | limiting in particular in the wavelength of the light source used for the exposure apparatus in this invention, It is preferable to use the light of a wavelength of 250 nm or less, More preferably, 200 nm or less, As an example, KrF excimer laser light (248 nm), Examples include ArF excimer laser light (193 nm), F ₂ excimer laser light (157 nm), EUV light (13.5 nm), and electron beams. Among these, it is more preferable to use ArF excimer laser light (193 nm).

The pattern forming method of the present invention can be applied to a pattern forming method by immersion exposure.
When performing an immersion exposure process, (1) after the film is formed on the substrate, before the exposure process and / or (2) after the process of exposing the film via the immersion liquid, the film is heated. Before the step of performing, the step of washing the surface of the membrane with an aqueous chemical solution may be performed.
The immersion liquid (immersion medium) is preferably a liquid that is transparent to the exposure wavelength and has the smallest possible temperature coefficient of refractive index so as to minimize distortion of the optical image projected onto the film. In particular, when the exposure light source is ArF excimer laser light (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 decreases 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 water to be used, distilled water is preferable. Further, pure water filtered through an ion exchange filter or the like may be used. Thereby, distortion of the optical image projected on the resist due to mixing of impurities can be suppressed.
Further, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

An immersion liquid poorly soluble film (hereinafter also referred to as “top coat”) may be provided between the resist film and the immersion liquid so that the resist film is not directly brought into contact with the immersion liquid. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers.

  When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.

  The pattern formation method of this invention may have an exposure process in multiple times. Exposure is performed using far ultraviolet rays, extreme ultraviolet rays, an electron beam, or the like, but when performing multiple exposures, the same light source or different light sources may be used. It is preferable to use ArF excimer laser light (wavelength: 193 nm) for the first exposure. It is also possible to have a plurality of exposure steps through the immersion medium.

  After the exposure step, preferably, (i) a heating step (also referred to as baking or PEB (post exposure bake)) is performed, followed by development and rinsing. Thereby, a good pattern can be obtained. The temperature of PEB is not particularly limited as long as a good resist pattern can be obtained, and is usually 40 ° C to 160 ° C. You may have a heating process in multiple times.

  In the present invention, (c) development is performed using a negative developer containing an organic solvent having a metal impurity content of 100 ppb or less to form a resist pattern. The content of metal impurities is preferably 50 ppb or less.

  Examples of metal impurities that can be contained in the negative developer include Na, K, Ca, Fe, Mg, Mn, Pd, Ni, Zn, Pt, Ag, and Cu. Among these, sodium ( It is preferable to suppress the content of Na) to 50 ppb or less and / or to suppress the content of iron (Fe) to 20 ppb or less. Thereby, the effect of the present invention is further improved.

  When the content of metal impurities is reduced, the resolution of the trench pattern is improved because the resist components, particularly the resin, aggregate in the developer with the metal impurities as the core during the negative development process. As a result, it is presumed that the resist component once dissolved is prevented from adhering to the pattern again due to aggregation.

  Further, although the cause of the effect of the present invention is not clear when the content of the metal impurity in the negative developer is reduced, the resist composition for the negative developer is reduced by reducing the metal impurity content. One possible reason is that the solubility of the product has improved. In particular, by reducing the content of specific metal components typified by sodium (Na) and iron (Fe), for example, the resin in the resist component aggregates with metal impurities as nuclei during the negative development process. As a result, the solubility of the resin in the developer is improved, and it is considered that fine trenches can be resolved with high sensitivity. Although the reason for the improvement of the density dependency is not clear, it is presumed that the solubility of the resin in the negative developer is involved.

  Examples of the method of setting the content of metal impurities contained in the negative developer to 100 ppb or less include a method of filtering the prepared negative developer with an ion exchange filter. In addition, the purity improvement of the material to be used, the separation washing, the treatment with an acidic ion exchange resin or a chelate resin, the treatment with a porous substance, etc. are known. The method for producing a negative developer of the present invention includes, for example, a step of filtering the negative developer with an ion exchange filter, and then filtering a particle component in the negative developer with an insoluble colloid removal filter. Examples include a method for producing a negative developer.

As an ion exchange filter that can be used in the present invention, a filter containing a cation exchange resin in which an appropriate cation exchange group is fixed to a resin membrane can be used. For example, a resin disclosed in US Pat. No. 5,234,789 can be used. Among these, a cation exchange type filter in which an ion exchange group is fixed to a polyethylene porous membrane or a polypropylene porous membrane is preferable. For example, Ion Clean (manufactured by Nippon Pole Co., Ltd.), Ion Clean AQ (manufactured by Nippon Pole Co., Ltd.), etc. However, the present invention is not limited to this.
The filtration rate by the ion exchange filter is preferably 500 to 10,000 cc / min / m ² .

  The insoluble colloid removal filter that can be used in the present invention is preferably a filter made of a synthetic resin, such as Microlith Optimizer DEV-16 / 40 (polyethylene filter manufactured by Microlith), Microguard Minichem (Microlith). Polyethylene filter), Enflon (Nippon Pole polytetrafluoroethylene filter), Ultipor N66 (Nippon Pole nylon 66 filter), Zetaplus (Cuno Cellulose filter), Electropore II (Cuno nylon 66) Filter) and the like, but the present invention is not limited to this.

  The pore sizes of the ion exchange filter and the insoluble colloid removal filter are both preferably 0.01 to 0.5 μm, and more preferably 0.01 to 0.1 μm.

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. .
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 monoethyl ether acetate, diethylene glycol monopropyl 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 the general formula (1) described later or a solvent represented by the general formula (2) described later is preferably used, and a solvent represented by the general formula (1) is used. More preferably, it is even more preferable to use alkyl acetate, and it is particularly preferable to use butyl acetate.
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 or the like having 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 glycol ether solvent having the above hydroxyl group, a glycol ether solvent having no 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. In the alkyl group of R and R ′, part of the alkyl group may be substituted with a hydroxyl group, a carbonyl 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, ethyl methoxyacetate, ethyl ethoxyacetate, 2-methoxybutyl acetate, 3-methoxy Butyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxy Pentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl- 4-methoxypentyl acetate, 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, pyruvate Butyl, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl Examples include -3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.

  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. The solvent represented by the general formula (1) 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. Although one or more types of combined solvents can be used, it is preferable to use one type in order to obtain stable performance. The mixing ratio (mass ratio) of the solvent represented by the general formula (1) and the combined solvent when using one type of combined solvent is usually 20:80 to 99: 1, preferably 50:50 to 97. : 3, more preferably 60:40 to 95: 5, particularly 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 an alkylene group.
The alkyl group of R ″, R ″ ″ and the alkylene group of R ″ ″ may be partially substituted with a hydroxyl group or a carbonyl group.
The alkylene group for 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 monoethyl 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 model Ethyl ether acetate, and propylene glycol monopropyl ether acetate.

  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. Although one or more types of combined solvents can be used, it is preferable to use one type in order to obtain stable performance. The mixing ratio (mass ratio) of the solvent represented by the general formula (2) and the combined solvent when one type of combined solvent is used is usually 20:80 to 99: 1, preferably 50:50 to 97. : 3, more preferably 60:40 to 95: 5, particularly preferably 60:40 to 90:10.

  The vapor pressure of the negative developer is preferably 5 kPa or less at 20 ° C., more preferably 3 kPa or less, and particularly preferably 2 kPa or less. By setting the vapor pressure of the negative developer to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved. As a result, the dimensions in the wafer surface are uniform. Sexuality improves.

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. That is, it is particularly preferable to use a nonionic fluorine-based surfactant or silicon-based 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.
When adding a surfactant to the developer, care must be taken not to mix metal impurities.

As a developing 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 method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer application nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method) ) Etc. can be applied.
The step of developing is preferably a step of supplying a negative developer onto the surface of the substrate while rotating the substrate.

  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 negative development, it is preferable to include a step of washing with a negative development rinsing solution containing an organic solvent.

  As the negative developing rinse solution containing an organic solvent, it is preferable to use an organic solvent containing an organic solvent having a metal impurity content of 100 ppb or less. Examples of the metal impurities that can be contained are Na, K, Ca, Fe Mg, Mn, Pd, Ni, Zn, Pt, Ag, Cu and the like.

  The method of setting the metal impurity content of the negative developing rinse solution containing an organic solvent to 100 ppb or less is the same as the preparation of the negative developer containing the organic solvent having the metal impurity content of 100 ppb or less. The method can be used.

  The rinsing liquid used in the rinsing step after negative development is not particularly limited as long as the resist pattern is not dissolved, and a solution containing a general organic solvent can be used. As the rinsing liquid, it is preferable to use a rinsing liquid containing at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. . More preferably, after the negative development, a cleaning step is performed using a rinse solution containing at least one organic solvent selected from a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent. More preferably, after the negative development, a step of washing with a rinse solution containing an alcohol solvent or an ester solvent is performed. Particularly preferably, after negative development, a step of washing with a rinsing solution containing a monohydric alcohol is performed. Here, examples of the monohydric alcohol used in the rinsing step after the negative development include linear, branched, and cyclic monohydric alcohols. Specifically, 1-butanol, 2-butanol, 3- Methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3 -Heptanol, 3-octanol, 4-octanol and the like can be used, and 1-hexanol, 2-hexanol, 1-pentanol and 3-methyl-1-butanol are preferable.

A plurality of these components may be mixed, or may be used by mixing with an organic solvent other than the above.
The step of washing with a rinse solution containing an organic solvent can be performed twice or more using two or more different rinse solutions separately.

  (E) It is preferable that the rinsing solution used in the step of washing with a rinsing solution containing an organic solvent has at least one developer component used in the step of (c) developing with a negative developer. .

  The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By setting the water content to 10% by mass or less, good development characteristics can be obtained.

  The vapor pressure of the rinse liquid used after negative development is preferably 0.05 kPa or more and 5 kPa or less at 20 ° C., more preferably 0.1 kPa or more and 5 kPa or less, and particularly preferably 0.12 kPa or more and 3 kPa or less. By setting the vapor pressure of the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and further, the swelling due to the penetration of the rinse solution is suppressed, and the dimensional uniformity in the wafer surface. Improves.

  An appropriate amount of a surfactant can be added to the rinse solution.

In the rinsing step, the wafer that has been subjected to negative development is cleaned using a rinsing 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), or the like can be applied.
The step of cleaning with the rinse liquid containing the organic solvent is preferably a process of supplying the rinse liquid onto the surface of the substrate while rotating the substrate.
In particular, it is preferable to perform a cleaning process by a spin coating method, rotate the substrate at a rotational speed of 2000 rpm to 4000 rpm after cleaning, and remove the rinse liquid from the substrate.

  In the present invention, it is further preferable that (e) development is performed using a positive developer to form a resist pattern.

As the positive developer, an alkali developer is preferably used. The alkaline developer is preferably a developer containing an aqueous solution containing at least one selected from the group consisting of primary amine compounds, secondary amine compounds, tertiary amine compounds and quaternary amine compounds. In particular, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di-n- Secondary amines such as butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Salt, pyrrole, pihe The alkaline aqueous solution of a cyclic amine such as gin may be used. Among these, it is preferable to use an aqueous solution of tetraethylammonium hydroxide.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer (based on the concentration of the amine compound in the developer and the total weight of the developer) is usually from 0.01 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
The time for developing with an alkali developer is usually 10 to 300 seconds.
The alkali concentration (and pH) and development time of the alkali developer can be appropriately adjusted according to the pattern to be formed.
The metal impurity concentration of the alkali developer is preferably 100 ppb or less.

(D) It is preferable to further include (R) a rinsing step after the step of developing using a positive developer.
(F) It is more preferable that the rinsing liquid used in the rinsing step is pure water.
An appropriate amount of a surfactant can be added to the rinse solution.

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 rinsing process or the process with the supercritical fluid, a heat treatment can be performed to remove moisture remaining in the pattern.

  The negative developing resist composition that can be used in the present invention will be described below.

<Negative development resist composition>
(A) Resin whose polarity is increased by the action of an acid and its solubility in a negative developer is reduced The polarity is increased by the action of an acid used in the resist composition of the present invention and the solubility in a negative developer is reduced. Resin (hereinafter also referred to as “resin (A)”) is a group (hereinafter referred to as an alkali-soluble group) that decomposes into the main chain or side chain of the resin or both the main chain and the side chain by the action of an acid. A resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, the polarity is increased by the action of an acid, the solubility in a negative developer is decreased, and A resin that increases the solubility in a positive developer (hereinafter, also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) is preferable. The reason is not clear, but it is likely that the positive polarity developer (preferably an alkali developer) and the negative developer (preferably, the polarities of the resin greatly change before and after irradiation with actinic rays or radiation. This is considered to be due to the improvement in dissolution contrast when developed using an organic solvent. Furthermore, a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure has high hydrophobicity, and a negative developer (preferably an organic solvent) is used to develop a region of the resist film with low light irradiation intensity. It is thought that the developability in the case improves.

  The resist composition of the present invention containing the resin (A) can be suitably used when irradiating ArF excimer laser light.

A preferable group as an acid-decomposable group contained in the resin (A) is a group obtained by substituting a hydrogen atom of an alkali-soluble group with a group capable of leaving with an acid.
Examples of alkali-soluble groups include carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) imides. 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 And the like.
Preferred alkali-soluble groups include carboxyl 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.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention includes a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and the following general formula (II- A resin containing at least one selected from the group of repeating units represented by AB) is preferred.

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R _{12 to} R ₁₄ represents a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group 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 general formula (II-AB):
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

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

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

In the general formulas (pI) to (pV), the alkyl group in R _{11 to} R ₂₅ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, n- Examples include propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like.

The cycloalkyl group represented by R _{12 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 carboxyl group, a sulfonic acid group, a phenolic hydroxyl group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (pV), preferably a carboxyl group The hydrogen atom of the sulfonic acid group is substituted with the structure represented by the 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), a repeating unit represented by the following general formula (pA) is preferable.

Here, R represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. To express. A single bond is preferable.
Rp ₁ represents any one of the general 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 shown by general formula (pA) is shown, this invention is not limited to this.

Examples of the halogen atom in the general formula (II-AB), R ₁₁ ′, and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

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

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

Examples of the alicyclic hydrocarbon skeleton to be formed include the same alicyclic hydrocarbon groups as R _{12 to} R _{25 in} the general formulas (pI) to (pV).

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

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

  The alicyclic hydrocarbon-based acid-decomposable resin 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), and (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 substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring.

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-16), R _{13 in the} above general formula (II-AB1) or (II-AB2) may be used. Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16) represents a group having a lactone structure) or 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 (preferably 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 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, or a divalent group obtained by combining these. Preferably, it is a linking group represented by a single bond or -Ab ₁ -CO _2- . Ab ₁ is a linear or branched alkylene group or a 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 having a lactone structure 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 preferably 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. 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 hydroxyl groups 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 hydroxyl groups and the remaining are hydrogen atoms.

As the repeating unit having a group represented by the general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2) is the above. Those having groups represented by general formulas (VIIa) to (VIId) (for example, R ₅ in —COOR ₅ represents groups represented by general formulas (VIIa) to (VIId)), or the following general formula ( A repeating unit represented by AIIa) to (AIId) can be exemplified.

In the 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 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, 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 preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By having these, the resolution in contact hole applications increases. 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 during 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 may further have a repeating unit having 1 to 3 groups represented by the general formula (F1). This improves line edge roughness performance.

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.
Rxa represents a hydrogen atom or an organic group (preferably an acid-decomposable protective group, alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group, 1-alkoxyethyl group). Represents.

The alkyl group of R _{50 to} R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, etc., preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl group or a trifluoromethyl group. be able to.
R _{50 to} R ₅₅ are preferably all fluorine atoms.

  Examples of the organic group represented by Rxa include an acid-decomposable protecting group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. , 1-alkoxyethyl group is preferable.

  The repeating unit having a group represented by the general formula (F1) is preferably a repeating unit represented by the following general formula (F2).

In general formula (F2),
Rx represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). Preferable substituents that the alkyl group of Rx may have include a hydroxyl group and a halogen atom.
Fa represents a single bond or a linear or branched alkylene group (preferably a single bond).
Fb represents a monocyclic or polycyclic hydrocarbon group.
Fc represents a single bond or a linear or branched alkylene group (preferably a single bond or a methylene group).
F ₁ represents a group represented by the general formula (F1).
p ₁ is an integer of 1 to 3.
The cyclic hydrocarbon group in Fb is preferably a cyclopentylene group, a cyclohexylene group, or a norbornylene group.

  Specific examples of the repeating unit having a group represented by the general formula (F1) are shown below, but the present invention is not limited thereto.

  The alicyclic hydrocarbon-based acid-decomposable resin may further have a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit 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 a repeating unit of 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, resolving power and heat resistance. In order to adjust sensitivity and the like, various repeating structural units can be contained.

  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.

Preferred embodiments of the alicyclic hydrocarbon-based acid-decomposable resin include the following.
(1) What has a repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by the said general formula (pI)-(pV) (side chain type).
Preferably, those having a (meth) acrylate repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV).
(2) Those having a repeating unit represented by formula (II-AB) (main chain type).
However, in (2), for example, the following can be further mentioned.
(3) Those having a repeating unit represented by the general formula (II-AB), a maleic anhydride derivative-based repeating unit and a (meth) acrylate-based repeating unit (hybrid type).

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 in all repeating structural units. -40 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the acid-decomposable group is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV), a general formula (II-AB). ) And at least one repeating unit among the repeating units of the copolymer component. The acid-decomposable group is preferably contained in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formula (pI) to general formula (pV).

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 20 to 70 in all the repeating structural units. The mol% is preferable, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20-50 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a group having a lactone structure is preferably from 10 to 70 mol%, more preferably from 20 to 60 mol%, still more preferably from all repeating structural units. It is 25-40 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an organic group having a polar group is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, still more preferably in all repeating structural units. Is 5 to 20 mol%.

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

  When the resist composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The alicyclic hydrocarbon-based acid-decomposable resin is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, and all of the repeating units may be any mixture of methacrylate repeating units / acrylate repeating units, It is preferable that the acrylate repeating unit is 50 mol% or less of the entire repeating unit.

  The alicyclic hydrocarbon-based acid-decomposable resin has at least a (meth) acrylate-based repeating unit having a group having a lactone structure, an organic group substituted with at least one of a hydroxyl group and a cyano group. It is preferable that it is a copolymer which has a unit and three types of repeating units of the (meth) acrylate type repeating unit which has an acid-decomposable group.

  Preferably, 20 to 50 mol% of repeating units having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), 20 to 50 mol% of repeating units having a group having a lactone structure, and polarity It is a ternary copolymer containing 5 to 30% of repeating units having an alicyclic hydrocarbon structure substituted with a group, or a quaternary copolymer containing 0 to 20% of other repeating units.

  Particularly preferable resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-7), and the following general formulas (ARL-1) to (ARL- 7) The alicyclic hydrocarbon structure substituted with 20 to 50 mol% of repeating units having a group having a lactone structure represented by formula (ARH-1) to (ARH-3) shown below. A terpolymer having 5 to 30 mol% of repeating units having a carboxylic acid group, a repeating unit having a structure represented by the general formula (F1) or an alicyclic hydrocarbon structure, and not exhibiting acid decomposability It is a quaternary copolymer containing 5 to 20 mol% of repeating units.

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxa ₁ and Rxb ₁ each independently represent a methyl group or an ethyl group, and Rxc ₁ represents a hydrogen atom or a methyl group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxd ₁ represents a hydrogen atom or a methyl group, and Rxe ₁ represents a trifluoromethyl group, a hydroxyl group, or a cyano group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group.)

  The alicyclic hydrocarbon-based acid-decomposable resin 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 resin (A) is preferably 1,000 to 200,000, more preferably 1,000 to 20,000, and particularly preferably 1,000 to 15, as a polystyrene-converted value by the GPC method. 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, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The degree of dispersion (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and 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 resist composition of the present invention, the blending amount of the resin (A) in the entire composition is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass in the total solid content.
In the present invention, the resin (A) may be used alone or in combination.

  When the negative developing resist composition of the present invention contains the resin (D) described later, the resin (A) does not have a fluorine atom and a silicon atom from the viewpoint of compatibility with the resin (D). Is preferred.

(B) Compound that generates acid upon irradiation with actinic ray or radiation The resist composition of the present invention comprises a compound that generates acid upon irradiation with actinic ray or radiation (also referred to as “photoacid generator” or “component (B)”). Contain).
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-A-62-153853, JP-A-63-146029, and the like 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 general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably a sulfonate anion, a carboxylate anion, a bis (alkylsulfonyl) amide anion, a 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 general 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 —, — Examples include groups connected by a connecting group such as S-, -SO _3- , and -SO ₂ N (Rd ₁ )-. 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 particularly 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 represented by 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 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

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

  More preferred (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 a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, 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, and 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 the general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₂₆ represents an alkyl group or an aryl group.
R ₂₂₇ and R ₂₂₈ each independently represents an alkyl group, an aryl group, or an electron-withdrawing group. R ₂₂₇ is preferably an aryl group. R ₂₂₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl 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% by mass, based on the total solid content of the resist composition. . By setting the content of the photoacid generator within this range, the exposure latitude when the resist pattern is formed and the crosslinking reactivity with the crosslinked layer forming material are improved.

(C) Solvent Solvents that can be used when preparing the resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, lactate alkyl ester, and alkoxypropion. Organic solvents such as alkyl acid, cyclic lactone (preferably having 4 to 10 carbon atoms), monoketone compound (preferably having 4 to 10 carbon atoms) which may contain a ring, alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate, etc. be able to.

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 include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, and γ-octano. Preferred are iclactone and α-hydroxy-γ-butyrolactone.

Examples of the monoketone compound 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-hexen-2-one 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3- Methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcycloheptanone, 3-methyl Preferred is cycloheptanone.

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 has a hydroxyl group in a structure, and the solvent which does not have a hydroxyl group as an organic solvent.
Examples of the solvent having 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. Propylene glycol monomethyl ether and ethyl lactate are particularly preferred.
Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide. Of these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are more preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropio Nate and 2-heptanone are particularly preferred.
The mixing ratio (mass) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is from 1/99 to 99/1, preferably from 10/90 to 90/10, more preferably from 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is particularly preferable from the viewpoint of coating uniformity.

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

  The solid content concentration of the resist composition of the present invention is usually 1.0 to 10% by mass, preferably 2.0 to 5.7% by mass, and more preferably 2.0 to 5.3% by mass. .

(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 (F2a) to (F4a),
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 (F2a) 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 (F3a) 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 (F4a) 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, -C (CF _{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 or branched alkyl group (preferably having 1 to 20 carbon atoms) 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 phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a urea 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 (C-IV).

In the general formulas (CI) to (C-IV),
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.

  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 , W ₅ and W ₆ each represents an organic group having at least one of a fluorine atom and a silicon atom.
W ₄ represents a fluorine atom or an organic group having at least one of a fluorine atom and a silicon atom.
m represents an integer of 1 to 5.
n represents 0 or 1.

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. A resin having a repeating unit (c) having a group (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.
The alkyl group for R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms.

Hereinafter, although the specific example of the repeating unit represented by general formula (Ia) is given, this invention is not limited to this. In the formula, X represents a hydrogen atom, a fluorine atom or a CF ₃ group.

  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.
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.

Resin (D) is a repeating unit represented by the following general formula (II) and / or the following general formula (I
It is preferable that it is resin which has a repeating unit represented by II).

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.
m and n represent a molar ratio of repeating units, and 0 ≦ m ≦ 100 and 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.

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

  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. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  The resin (D) is preferably stable to an acid and insoluble in an alkaline developer. Moreover, it is preferable that it is resin soluble in a negative developing solution.

The resin (D) is preferably a resin that is stable to acids and insoluble in an alkaline developer. Specifically, it is preferable from the viewpoint of the followability of the immersion liquid that it does not have an alkali-soluble group and a group whose solubility in a developing solution is increased by the action of acid or alkali.
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, if the resin (D) contains a hydrophilic polar group, the followability of immersion water tends to decrease, and therefore does not have a polar group selected from a hydroxyl group, an alkylene glycol, an ether group, and a sulfone group. Is more preferable.

  (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 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 degree of dispersion (molecular weight distribution) of the resin (D) is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2, particularly preferably 1 to 1.7. The smaller the degree of dispersion, the better the resolution, resist shape, resist pattern sidewall, roughness, and the like.

  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 addition amount of the resin (D) in the negative developing resist composition is preferably 0.1 to 5% by mass, more preferably 0.2 to 3%, based on the total solid content of the resist composition. It is 0.0 mass%, More preferably, it is 0.3-2.0 mass%.

  The resin (D), like the 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 or the like by HPLC. Preferably, this not only can further improve the sensitivity, resolution, process stability, pattern shape, and the like as a resist, but also provides a resist that does not change with time, such as foreign matter in liquid or sensitivity.

  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 examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. 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, and the like. 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 contacted to precipitate the resin (step a), the resin is separated from the solution (step b), and dissolved again in the solvent to obtain a resin solution ( A) is prepared (step c), and then a solvent in which the resin is hardly soluble or insoluble is added to the resin solution (A) in a volume amount (preferably 5 times or less) of the resin solution (A). The method may include depositing a resin solid by contacting (step d) and separating the deposited 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.

  Hereinafter, although the specific example of resin (D) is shown, this invention is not limited to this.

(E) Basic compound The 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) to (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.
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 a resist composition, 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 resist composition of the present invention preferably further contains (F) a surfactant, and is a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant). , A surfactant having both a fluorine atom and a silicon atom), or more preferably two or more.

When the resist composition of the present invention contains the surfactant (F), when using an exposure light source of 250 nm or less, particularly 220 nm or less, a resist pattern with good sensitivity and resolution and less adhesion and development defects can be obtained. It becomes possible to give.
Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include 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-204G, 208, 230G, 204 , Mention may be made of 208D, 212D, 218D, the fluorine-based surfactant or silicone-based surfactants such as 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, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C 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 usage-amount of surfactant becomes like this. Preferably it is 0.01-10 mass% with respect to resist composition whole quantity (except a solvent), More preferably, it is 0.1-5 mass%.

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

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

  These (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 resist composition of the present invention further promotes solubility in dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors, and developers as necessary. The compound to be made (for example, a phenol compound having a molecular weight of 1000 or less, an alicyclic compound having a carboxyl group, or an aliphatic compound) and the like can be contained.

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

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

<Preparation of negative developer>
Regarding the solvents contained in the negative developers (ND-1) to (ND-17) shown in Table 1 below, ion-exchange filters (Nippon Pole) are used for the negative developers (ND-13) to (ND-14). Filtration with Ion Clean (manufactured by Ion Clean Co., Ltd., pore size: 0.1 μm) was performed twice, and the negative developers (ND-1) to (ND-12) were filtered only once. Further, the negative developers (ND-15) to (ND-17) were not filtered with an ion exchange filter. Then, each solvent was filtered with a polytetrafluoroethylene filter (ENFLON manufactured by Nippon Pole Co., Ltd., pore size: 0.1 μm) to prepare negative developers (ND-1) to (ND-17).
Using a polarized Zeeman atomic absorption spectrophotometer (manufactured by Hitachi, Z-9000), the content (unit ppb) of the metal impurities contained in the negative developer obtained by the above-described procedure was Na, K, Ca, Measurements were performed on eight elements of Fe, Cu, Mg, Mn, and Zn. The results are also shown in Table 1 below.

  In Table 1, the numerical value in parentheses represents a mixing mass ratio of two types of solvents when two types of organic solvents are used in combination as a negative developer.

Synthesis Example 1 (Synthesis of Resin (A1))
Under a nitrogen stream, 20 g of a 6/4 (mass ratio) mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether was placed in a three-necked flask and heated to 80 ° C. (solvent (1)). γ-butyrolactone methacrylate, hydroxyadamantane methacrylate and 2-methyl-2-adamantyl methacrylate are mixed into propylene glycol monomethyl ether acetate and 6/4 (mass ratio) of propylene glycol monomethyl ether in a molar ratio of 40/25/35. It melt | dissolved and the 22 mass% monomer solution (200g) was prepared. Furthermore, 8 mol% of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the monomer, and a dissolved solution was added dropwise to the solvent (1) over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then poured into 1800 ml of hexane / 200 ml of ethyl acetate. The precipitated powder was collected by filtration and dried to obtain 37 g of Resin (A1). The weight average molecular weight in terms of standard polystyrene of the obtained resin (A1) was 5500, and the dispersity (Mw / Mn) was 1.65.

  Similarly, resins (A2) to (A15) were synthesized.

  Hereinafter, the structures of the resins (A2) to (A15) are shown. Table 2 below shows the composition ratio (molar ratio), weight average molecular weight, and dispersity of the resins (A1) to (A15).

<Preparation of resist composition>
As shown in Table 3 below, each component was dissolved in a solvent to prepare a solution having a solid content concentration of 5.3% by mass, and this was filtered through a 0.05 μm polyethylene filter to form resist compositions (Ra1) to (Ra17). ) Was prepared.

  Abbreviations in Table 3 are as follows.

N-1: N, N-diphenylaniline N-2: Diazabicyclo [4.3.0] nonene N-3: 4-Dimethylaminopyridine

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)

SL-1: Propylene glycol monomethyl ether acetate SL-2: Propylene glycol monomethyl ether

  Table 4 below shows the weight average molecular weight and repeating unit molar ratio of the resin (D) described in the table.

  Evaluation was performed by the following method using the resist compositions (Ra1) to (Ra17) prepared above.

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 resist composition (Ra1) was spin-coated thereon and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was exposed through a mask for pattern formation using a PAS5500 / 1100 manufactured by ASML equipped with an NA0.75 lens as an ArF excimer laser scanner. After exposure, after heating at 120 ° C. for 60 seconds, while developing the wafer for 60 seconds (negative development) with the negative developer (ND-1) using the spray method while rotating the wafer at a rotation speed of 1000 rpm, rotation The wafer is rinsed with 1-hexanol using a spray method for 30 seconds as it is, and then the wafer is rotated at 4000 rpm for 30 seconds to remove the rinse solution, whereby a 90 nm (1: 1) line is obtained. An andspace resist pattern was obtained.

Example 2
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 resist composition (Ra1) was spin-coated thereon and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. Using the TWINSCAN / 1250i manufactured by ASML equipped with a lens of NA0.85 as an ArF excimer laser scanner, the obtained wafer was passed through a mask for pattern formation using pure water as an immersion liquid. Immersion exposure. After the exposure, the wafer was rotated at 2000 rpm to remove water. Then, after heating at 120 ° C. for 60 seconds, the wafer is rotated at a rotation speed of 1000 rpm and developed with a negative developer (ND-1) for 60 seconds using a spray method (negative development). The wafer was rinsed with 1-hexanol for 30 seconds using a spray method, and then the wafer was rotated at 4000 rpm for 30 seconds to remove the rinse solution, thereby 90 nm (1: 1) line and space. A resist pattern was obtained.

Examples 3 to 15 and Comparative Examples 1 to 3
A 90 nm (1: 1) line-and-space resist in the same manner as in Example 1 except that the resist composition, negative developer, and negative developer rinse were changed to the combinations shown in Table 5 below. Got a pattern.

Example 16
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 resist composition (Ra1) was spin-coated thereon and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was exposed through a mask for pattern formation using a PAS5500 / 1100 manufactured by ASML equipped with an NA0.75 lens as an ArF excimer laser scanner. After exposure, the film is heated at 120 ° C. for 60 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38% by mass) (positive developer) for 60 seconds (positive development), rinsed with pure water, and pitched. A pattern of 360 nm and a line width of 270 nm was obtained. Next, while rotating the wafer at a rotation speed of 1000 rpm, development is performed for 60 seconds with a negative developer (ND-1) using a spray method (negative development), and the wafer is rotated using the spray method. After rinsing with 1-hexanol for 30 seconds, the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds to remove the rinse solution, thereby obtaining a 90 nm (1: 1) line-and-space resist pattern.

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 resist composition (Ra1) was spin-coated thereon and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was exposed through a mask for pattern formation using a PAS5500 / 1100 manufactured by ASML equipped with an NA0.75 lens as an ArF excimer laser scanner. After exposure, after heating at 120 ° C. for 60 seconds, while developing the wafer for 60 seconds (negative development) with the negative developer (ND-1) using the spray method while rotating the wafer at a rotation speed of 1000 rpm, rotation The wafer is rinsed with 1-hexanol using a spray method for 30 seconds as it is, and then the wafer is rotated at 4000 rpm for 30 seconds to remove the rinse solution, whereby a pattern with a pitch of 360 nm and a line width of 270 nm is obtained. Got. Next, the film was developed with a tetramethylammonium hydroxide aqueous solution (2.38% by mass) (positive developer) for 60 seconds (positive development), rinsed with pure water, and 90 nm (1: 1) line and space. A resist pattern was obtained.

Evaluation of Sensitivity Using a length-measuring scanning electron microscope (S-9260 manufactured by Hitachi, Ltd.), a 90 nm (1: 1) line and space resist pattern obtained in Examples 1 to 17 and Comparative Examples 1 to 3 was used. Observed, the value of exposure amount that reproduces a line-and-space mask pattern with a line width of 90 nm was defined as sensitivity (also referred to as optimum exposure amount). A smaller value indicates better performance. The results are shown in Table 5.

Evaluation of density dependence Using a length-measuring scanning electron microscope (S-9260 manufactured by Hitachi, Ltd.) for the 90 nm (1: 1) line and space resist pattern obtained in Examples 1 to 17 and Comparative Examples 1 to 3 The exposure dose that reproduces the 90 nm line and space 1: 1 is the optimum dose, and the line width of the dense pattern (line: space = 1: 1) at the optimum exposure dose and the isolated line The line width of the pattern (line: space = 1: 5) was measured, and the difference was used as an index of density dependence. The smaller this value, the better the performance. The results are shown in Table 5.

Evaluation of Resolution of Trench Pattern Using a scanning microscope (S-9260 manufactured by Hitachi, Ltd.), the 90 nm (1: 1) line and space resist pattern obtained in Examples 1-17 and Comparative Examples 1-3. Observed, the exposure amount that reproduces the above 90 nm line and space 1: 1 is the optimum irradiation amount, and when the exposure amount is increased from the optimum exposure amount and the trench (indicating the space) line width is narrowed, the adjacent pattern The minimum trench (space) line width that is resolved without being connected to each other is defined as the resolution of the trench pattern. The smaller the value, the finer the trench pattern resolution, and the better the resolution. The results are shown in Table 5.

  From Table 5, it is clear that the pattern forming method of the present invention can stably form a fine pattern with high sensitivity and excellent trench pattern resolution and further with high density dependence.

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. 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 (9)

(A) A step of applying a negative developing resist composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a negative developing solution decreases.
(A) an exposure step; and (c) a pattern forming method comprising: developing with a negative developer containing an organic solvent having a metal impurity content of 100 ppb or less.   2. The pattern according to claim 1, wherein the step of developing using a negative developer comprises developing with a negative developer containing an organic solvent having a sodium content of 50 ppb or less. Forming method.   (C) The step of developing using a negative developer comprises developing using a negative developer containing an organic solvent having an iron content of 20 ppb or less. Pattern forming method.   (C) The step of developing using a negative developer comprises at least one organic solvent selected from ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents and hydrocarbon solvents. The pattern forming method according to claim 1, wherein the pattern forming method is a step performed using a negative developer. (C) The step of developing using a negative developer is a step of developing using a developer containing a solvent represented by the following general formula (1). The pattern formation method in any one of.

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.   (C) The pattern forming method according to any one of claims 1 to 5, wherein the step of developing using a negative developer is a step of using a developer containing butyl acetate. (C) The step of developing using a negative developer is a step of developing using a developer containing a solvent represented by the following general formula (2). The pattern formation method in any one of.

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 ′ ″ represents an alkylene group or a cycloalkylene group.   The pattern forming method according to claim 1, further comprising (d) a step of developing using a positive developer.   A negative developing solution for use in the pattern forming method according to claim 1, wherein the negative developing solution is produced through a step of filtering with an ion exchange filter.

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