JP6603303B2 - PATTERN FORMING METHOD, RESIST PATTERN, ELECTRONIC DEVICE MANUFACTURING METHOD, AND ELECTRONIC DEVICE - Google Patents

Description

The present invention relates to a pattern forming method, a resist pattern formed by the pattern forming method, an electronic device manufacturing method including the pattern forming method, and an electronic device manufactured by the electronic device manufacturing method.
More specifically, 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 and a thermal head, and other photofabrication lithography processes, and the above pattern forming method. The present invention relates to a formed resist pattern, an electronic device manufacturing method including the pattern forming method, and an electronic device manufactured by the electronic device manufacturing method.

  Conventionally, in a manufacturing process of a semiconductor device such as an IC, fine processing by lithography using various resist compositions has been performed. For example, Patent Document 1 provides “(a) providing a semiconductor substrate including one or more layers to be patterned; (b) forming a photoresist layer on the one or more layers to be patterned; c) coating a photoresist topcoat composition on the photoresist layer, the topcoat composition comprising a basic quencher, a polymer and an organic solvent; (d) exposing the layer to actinic radiation; and ( e) developing the exposed film with an organic solvent developer; a method of forming an electronic device comprising:

JP 2013-061647 A

  As a result of studying the method described in Patent Document 1, the present inventors found that exposure latitude (EL) was relatively good, but CD uniformity (CDU: Critical Dimension Uniformity) and line edge roughness. It has been found that (LER: Line Edge Roughness) may be insufficient.

  The present invention has been made in view of the above points. A pattern forming method in which both CDU and LER and EL are favorable, a resist pattern formed by the pattern forming method, and an electronic device including the pattern forming method are disclosed. It is an object of the present invention to provide a manufacturing method and an electronic device manufactured by the manufacturing method of the electronic device.

The present inventors have found that the above object can be achieved by adopting the following configuration. That is, the present invention provides the following [1] to [8].
[1] An actinic ray-sensitive or radiation-sensitive resin composition containing a resin whose polarity is increased by the action of an acid and a compound that generates an acid upon irradiation with an actinic ray or radiation is applied onto a substrate, Step a for forming a resist film, Step b for forming an upper layer film on the resist film by applying a composition for forming an upper layer film on the resist film, and the resist film having the upper layer film formed thereon And a step d of developing the exposed resist film using a developer containing an organic solvent to form a pattern, the actinic ray-sensitive or radiation-sensitive resin composition. The content of the compound that generates an acid upon irradiation with actinic rays or radiation in the product is 16.5% by mass or more based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition, Formation Law.
[2] The pattern forming method according to [1], wherein the composition for forming an upper layer film contains at least one selected from the group consisting of the following (A1), (A2) and (A3).
(A1) Basic compound or base generator (A2) A compound containing at least one bond or group selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond and an ester bond (A3 ) Onium salt [3] The pattern forming method as described in [1] or [2] above, wherein the composition for forming an upper layer film contains a resin having a glass transition temperature of 50 ° C. or higher.
[4] The above [1] to [1], wherein the compound capable of generating an acid upon irradiation with active light or radiation is a compound capable of generating an acid upon irradiation with active light or radiation represented by the general formula (3) described later. 3]. The pattern forming method according to any one of [3].
[5] The step b is a step of forming an upper layer film on the resist film by applying the upper layer film forming composition on the resist film and then heating at 100 ° C. or higher. The pattern forming method according to any one of [1] to [4].
[6] A resist pattern formed by the pattern forming method according to any one of [1] to [5] above.
[7] A method for manufacturing an electronic device, comprising the pattern forming method according to any one of [1] to [5] above.
[8] An electronic device manufactured by the method for manufacturing an electronic device according to [7].

  According to the present invention, the CDU and LER and EL are both good pattern formation methods, the resist pattern formed by the pattern formation method, the electronic device manufacturing method including the pattern forming method, and the electronic device manufacturing. An electronic device manufactured by the method can be provided.

Hereinafter, modes for carrying out the present invention will be described.
In addition, in the description of group (atomic group) in this specification, the description which is not describing substitution and non-substitution includes what has a substituent with what does not have 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).
“Actinic light” or “radiation” in the present specification means, for example, an emission line spectrum of a mercury lamp, far ultraviolet rays represented by an excimer laser, extreme ultraviolet rays (EUV light), X-rays, electron beams, and the like. In the present invention, light means actinic rays or radiation. In addition, the term “exposure” in this specification is not limited to exposure with far ultraviolet rays, X-rays, EUV light and the like represented by mercury lamps and excimer lasers, but also particle beams such as electron beams and ion beams, unless otherwise specified. Include drawing in exposure.

  In the following, first, after describing the pattern forming method of the present invention, the actinic ray-sensitive or radiation-sensitive resin composition used for the pattern forming method of the present invention (hereinafter also referred to as “resist composition of the present invention”). The upper layer film-forming composition (hereinafter also referred to as “topcoat composition”) will be described.

[Pattern formation method]
The pattern forming method of the present invention comprises a substrate having an actinic ray-sensitive or radiation-sensitive resin composition containing a resin whose polarity is increased by the action of an acid and a compound that generates an acid upon irradiation with an actinic ray or radiation. The step a for forming a resist film by coating, the step b for forming an upper layer film on the resist film by applying the composition for forming an upper layer film on the resist film, and the upper layer film are formed. A step c for exposing the resist film; and a step d for developing the exposed resist film using a developer containing an organic solvent to form a pattern. The content of the compound capable of generating an acid upon irradiation with the actinic ray or radiation in the radiation-sensitive resin composition is 16.5% by mass or more based on the total solid content of the actinic-ray-sensitive or radiation-sensitive resin composition. There is a pattern forming method.
Thereby, both good CDU and LER and good EL can be realized.

<Step a>
In step a, the resist composition of the present invention is applied onto a substrate to form a resist film (actinic ray sensitive or radiation sensitive film). The coating method is not particularly limited, and a conventionally known spin coating method, spray method, roller coating method, dipping method and the like can be used, and the spin coating method is preferable.
After applying the resist composition of the present invention, the substrate may be 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.

The substrate on which the resist film is formed is not particularly limited, and an inorganic substrate such as silicon, SiO ₂ or SiN, a coated inorganic substrate such as SOG, a semiconductor manufacturing process such as an IC, a circuit substrate such as a liquid crystal or a thermal head In addition, a substrate generally used in the manufacturing process of the present invention, and also in other photofabrication lithography processes 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, AUV 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. It can also be formed using a commercially available composition for forming an organic antireflection film.

<Process b>
In step b, an upper layer film-forming composition (topcoat composition) is applied on the resist film formed in step a, and then heated (pre-baked (PB)) as necessary, thereby forming a resist. An upper film (hereinafter also referred to as “top coat”) is formed on the film.

CDU and LER are improved by adding a large amount of a compound (photoacid generator) that generates acid upon irradiation with actinic rays or radiation in the resist film. On the other hand, however, if the photoacid generator in the resist film becomes excessive, the glass transition temperature of the resist film is lowered, the generated acid is likely to diffuse, and EL may be inferior.
At this time, forming a top coat on the resist film raises the glass transition temperature of the entire film and suppresses acid diffusivity, so that a good EL can be obtained.

For the reason that the effect of the present invention is more excellent, the pre-baking temperature in the step b (hereinafter also referred to as “PB temperature”) is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, and further preferably 110 ° C. or higher. 120 ° C. or higher is particularly preferable, and over 120 ° C. is most preferable.
Although the upper limit of PB temperature is not specifically limited, For example, 200 degrees C or less is mentioned, 170 degrees C or less is preferable, 160 degrees C or less is more preferable, 150 degrees C or less is still more preferable.

When the exposure in step c described later is immersion exposure, the top coat is disposed between the resist film and the immersion liquid and functions as a layer that does not directly contact the resist film with the immersion liquid. In this case, preferable properties of the top coat (top coat composition) include suitability for application to a resist film, transparency to radiation, particularly 193 nm, and poor solubility in an immersion liquid (preferably water). Further, it is preferable that the top coat is not mixed with the resist film and can be uniformly applied to the surface of the resist film.
In addition, in order to apply | coat a topcoat composition uniformly on the surface of a resist film, without melt | dissolving a resist film, it is preferable that a topcoat composition contains the solvent which does not melt | dissolve a resist film. As the solvent that does not dissolve the resist film, it is more preferable to use a solvent having a component different from the organic developer described later. A method for applying the top coat composition is not particularly limited, and a conventionally known spin coat method, spray method, roller coat method, dipping method, or the like can be used.
From the viewpoint of transparency with respect to 193 nm, the topcoat composition preferably contains a resin that does not substantially contain an aromatic. Specifically, for example, at least one of a fluorine atom and a silicon atom described later is used. And a resin having a repeating unit having a CH ₃ partial structure in the side chain portion, but are not particularly limited as long as it dissolves in a solvent that does not dissolve the resist film.

The thickness of the top coat is not particularly limited, but is usually 5 nm to 300 nm, preferably 10 nm to 300 nm, more preferably 20 nm to 200 nm, and still more preferably 30 nm to 100 nm, from the viewpoint of transparency to the exposure light source. .
After forming the top coat, the substrate is heated as necessary.
The refractive index of the top coat is preferably close to the refractive index of the resist film from the viewpoint of resolution.
The top coat is preferably insoluble in the immersion liquid, and more preferably insoluble in water.
The receding contact angle of the top coat is preferably 50 to 100 degrees, and preferably 80 to 100 degrees, from the viewpoint of immersion liquid followability. More preferred.
In immersion exposure, the immersion head needs to move on the wafer following the movement of the exposure head to scan the wafer at high speed and form an exposure pattern. In order to obtain better resist performance, it is preferable to have a receding contact angle in the above range.

  When peeling the top coat, an organic developer described later may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist film is preferable. From the viewpoint that the top coat can be peeled off simultaneously with the development of the resist film, the top coat is preferably peelable by an organic developer. The organic developer used for the stripping is not particularly limited as long as it can dissolve and remove the low-exposed portion of the resist film, and will be described later ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents. Developers containing polar solvents and hydrocarbon solvents such as ketone solvents, ester solvents, alcohol solvents, ether solvents are preferred, and developers containing ester solvents are more preferred. A developer containing butyl acetate is more preferred.

From the viewpoint of peeling with an organic developer, the topcoat preferably has a dissolution rate in the organic developer of 1 to 300 nm / sec, more preferably 10 to 100 nm / sec.
Here, the dissolution rate of the topcoat in the organic developer is a film thickness reduction rate when the topcoat is formed and then exposed to the developer. Speed.
By setting the dissolution rate of the top coat in the organic developer to 1 nm / sec or more, preferably 10 nm / sec or more, there is an effect of reducing development defects after developing the resist film. Also, by setting it to 300 nm / sec or less, preferably 100 nm / sec, the line edge roughness of the pattern after developing the resist film is likely to be better due to the effect of reducing the exposure unevenness during immersion exposure. effective.
The top coat may be removed using another known developer, for example, an alkaline aqueous solution. Specific examples of the aqueous alkali solution that can be used include an aqueous solution of tetramethylammonium hydroxide.

<Process c>
The exposure in step c can be performed by a generally known method. For example, the resist film on which the top coat is formed is irradiated with actinic rays or radiation through a predetermined mask. At this time, preferably, the actinic ray or radiation is irradiated through the immersion liquid, but is not limited thereto. Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally.
The wavelength of the light source used in the exposure apparatus in the present invention is not particularly limited, but it is preferable to use light having a wavelength of 250 nm or less. Examples thereof include KrF excimer laser light (248 nm) and ArF excimer laser light (193 nm). F ₂ excimer laser light (157 nm), EUV light (13.5 nm), electron beam, and the like. Among these, it is preferable to use ArF excimer laser light (193 nm).

When performing immersion exposure, the surface of the film may be washed with an aqueous chemical before exposure and / or after exposure and before heating described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient that is as small as possible so as to minimize distortion of the optical image projected onto the film. In the case of ArF excimer laser light (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and easy handling in addition to the above-described viewpoints.
When water is used, an additive (liquid) that reduces the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist film on the substrate 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 film 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.

  The pattern formation method of this invention may have the process c (exposure process) in multiple times. In this case, the same light source or different light sources may be used for the multiple exposures, but ArF excimer laser light (wavelength: 193 nm) is preferably used for the first exposure.

  After exposure, preferably, heating (also referred to as “baking” or “PEB”) is performed, and development (preferably further rinsing) is performed. 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. PEB may be performed once or multiple times.

<Process d>
In step d, a negative resist pattern is formed by developing using a developer containing an organic solvent. Step d is preferably a step of simultaneously removing soluble portions of the resist film.
As the developer containing an organic solvent (hereinafter also referred to as “organic developer”) used in step d, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, etc. Examples thereof include a developer containing a solvent and a hydrocarbon solvent.
Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexanone, Examples include phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl acetone, acetonyl acetone, ionone, diacetyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate.
Examples of ester solvents include methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate (n-butyl acetate), pentyl acetate, hexyl acetate, isoamyl acetate, butyl propionate (n-butyl propionate), butyl butyrate, butyric acid Isobutyl, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate , Methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, methyl 2-hydroxyisobutyrate, isobutyl isobutyrate, Propionic acid butyl and the like.
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 and n-decanol; glycol solvents such as ethylene glycol, propylene glycol, diethylene glycol and triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, And glycol ether solvents such as methoxymethylbutanol; .
Examples of the ether solvent include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.
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 solvent include aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as pentane, hexane, octane and decane;
A plurality of the above solvents may be mixed, or may be used by mixing with a solvent other than the above or water. However, in order to fully exhibit the effects of the present invention, the water content of the developer as a whole is preferably less than 10% by mass, and more preferably substantially free of moisture.
That is, the content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, and more preferably 95% by mass or more and 100% by mass or less with respect to the total amount of the developer.

  Among these, the organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. More preferably, a developer containing a ketone solvent or an ester solvent is more preferred, and a developer containing butyl acetate, butyl propionate, or 2-heptanone is more preferred.

The vapor pressure of the organic developer at 20 ° C. is preferably 5 kPa or less, more preferably 3 kPa or less, and even more preferably 2 kPa or less. By setting the vapor pressure of the organic developing solution to 5 kPa or less, evaporation of the developing solution on the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved. As a result, the dimension in the wafer surface is uniform. Sexuality improves.
Specific examples having a vapor pressure of 5 kPa or less (2 kPa or less) include the solvents described in paragraph <0165> of JP-A No. 2014-71304.

An appropriate amount of a surfactant can be added to the organic developer as required.
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-A-63-334540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, US Pat. No. 5,405,720, The surfactants described in the specifications of US Pat. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant.
The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.

  The organic developer may contain a basic compound. Specific examples and preferred examples of the basic compound that can be contained in the organic developer used in the present invention are the same as those described later as basic compounds that can be contained in the actinic ray-sensitive or radiation-sensitive resin composition.

  As a development method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a 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 discharging the developer while scanning the developer discharge nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc.

  Moreover, you may have the process of stopping image development, substituting with another solvent after the process developed using the developing solution containing an organic solvent.

After the step of developing using a developer containing an organic solvent, a step of washing with a rinse solution may be included.
The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used. The rinsing liquid is selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents, which are listed above as organic solvents contained in organic developers, for example. It is preferable to use a rinse solution containing at least one organic solvent. More preferably, the step of washing with a rinsing liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents. I do. More preferably, the washing step is performed using a rinse liquid containing a hydrocarbon solvent, an alcohol solvent or an ester solvent. Particularly preferably, the cleaning step is performed using a rinse solution containing a monohydric alcohol. Further, hydrocarbon solvents such as decane and undecane are also preferable.

  Here, examples of the monohydric alcohol used in the rinsing step include linear, branched, and cyclic monohydric alcohols, and specifically include 1-butanol, 2-butanol, and 3-methyl-1. -Butanol, 3-methyl-2-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol, 1-hexanol, 2- Hexanol, 3-hexanol, 4-methyl-2-hexanol, 5-methyl-2-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-methyl-2-heptanol, 5-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 4-methyl-2-octanol, 5 Methyl-2-octanol, 6-methyl-2-octanol, 2-nonanol, 4-methyl-2-nonanol, 5-methyl-2-nonanol, 6-methyl-2-nonanol, 7-methyl-2-nonanol, 2-decanol and the like can be used, and preferably 1-hexanol, 2-hexanol, 1-pentanol, 3-methyl-1-butanol, and 4-methyl-2-heptanol.

Examples of the hydrocarbon solvent used in the rinsing step include aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane (n-decane), and undecane. And the like.
When an ester solvent is used as the rinsing liquid, a glycol ether solvent may be used in addition to the ester solvent (one or two or more). Specific examples in this case include using an ester solvent (preferably butyl acetate) as a main component and a glycol ether solvent (preferably propylene glycol monomethyl ether (PGME)) as a subcomponent. Thereby, residue defects are suppressed.

A plurality of the above components may be mixed, or may be used by mixing with an organic solvent other than the above.
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 rinsing liquid is preferably 0.05 to 5 kPa, more preferably 0.1 to 5 kPa, further preferably 0.12 to 3 kPa at 20 ° C. By setting the vapor pressure of the rinsing liquid to 0.05 to 5 kPa, the temperature uniformity in the wafer surface is improved, and further, the swelling due to the penetration of the rinsing liquid is suppressed, and the dimensional uniformity in the wafer surface is good. Turn into.
An appropriate amount of a surfactant can be added to the rinse solution.

  In the rinsing step, the wafer that has been developed using the developer containing the organic solvent is cleaned using the rinse solution containing the organic solvent. The method of the cleaning treatment is not particularly limited. For example, a method of continuously discharging the rinse liquid onto the substrate rotating at a constant speed (rotary coating method), and immersing the substrate in a bath filled with the rinse liquid for a certain period of time. A method (dip method), a method of spraying a rinsing liquid on the substrate surface (spray method), and the like can be applied. Among them, a cleaning treatment is performed by a spin coating method, and after cleaning, the substrate is rotated at a speed of 2000 rpm to 4000 rpm. It is preferable to rotate and remove the rinse liquid from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. The developing solution and the rinsing solution remaining between the patterns and inside the patterns are removed by baking. The heating step after the rinsing step is usually 40 to 160 ° C., preferably 70 to 95 ° C., and usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

In the pattern forming method of the present invention, development may be performed using an alkaline developer after development using an organic developer. A portion with low exposure intensity is removed by development using an organic solvent, but a portion with high exposure intensity is also removed by further development using an alkaline developer. In this way, the multiple development process in which development is performed a plurality of times enables pattern formation without dissolving only the intermediate exposure intensity region, so that a finer pattern than usual can be formed (paragraph of JP 2008-292975 A). <Mechanism similar to <0077>).
Examples of the alkali developer include 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, Secondary amines such as di-n-butylamine; Tertiary amines such as triethylamine and methyldiethylamine; Alcohol amines such as dimethylethanolamine and triethanolamine; Fourth amines such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions such as quaternary ammonium salts; cyclic amines such as pyrrole and piperidine; and the like can 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 is usually 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.
After the development with an alkali developer, the substrate may be washed with a rinse solution. As the rinse solution, pure water may be used, and an appropriate amount of a surfactant may be added.
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.
Further, after the rinsing process or the supercritical fluid process, a heat treatment can be performed to remove moisture remaining in the pattern.

Various materials used in the pattern forming method of the present invention (for example, the resist composition of the present invention, a resist solvent, a developing solution, a rinsing solution, an antireflection film forming composition, a top coat composition, etc.) are made of metal, etc. It is preferable not to contain impurities. The content of impurities contained in these materials is preferably 1 ppm or less, more preferably 100 ppt or less, still more preferably 10 ppt or less, and particularly preferably (not more than the detection limit of the measuring device).
Examples of a method for removing impurities such as metals from the various materials include filtration using a filter. The filter pore size is preferably 10 nm or less, more preferably 5 nm or less, and still more preferably 3 nm or less. As a material of the filter, a filter made of polytetrafluoroethylene, polyethylene, or nylon is preferable. A filter that has been washed in advance with an organic solvent may be used. In the filter filtration step, a plurality of types of filters may be connected in series or in parallel. When a plurality of types of filters are used, filters having different pore diameters and / or materials may be used in combination. Moreover, various materials may be filtered a plurality of times, and the step of filtering a plurality of times may be a circulating filtration step.
Moreover, as a method for reducing impurities such as metals contained in the various materials, a raw material having a low metal content is selected as a raw material constituting the various materials, and filter filtration is performed on the raw materials constituting the various materials. For example, the inside of the apparatus may be lined with Teflon (registered trademark), and distillation may be performed under a condition in which contamination is suppressed as much as possible. The preferable conditions for filter filtration performed on the raw materials constituting the various materials are the same as those described above.
In addition to filter filtration, impurities may be removed by an adsorbent, or filter filtration and adsorbent may be used in combination. As the adsorbent, known adsorbents can be used. For example, inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon can be used.

In addition, you may produce the mold for imprint using the resist composition of this invention, For the details, please refer to patent 4109085 and Unexamined-Japanese-Patent No. 2008-162101, for example.
The pattern forming method of the present invention can also be used for guide pattern formation in DSA (Directed Self-Assembly) (see, for example, ACS Nano Vol. 4 No. 8 Pages 4815-4823).
The resist pattern formed by the above method can be used as a core material (core) of a spacer process disclosed in, for example, Japanese Patent Application Laid-Open Nos. 3-270227 and 2013-164509.
A method for improving the surface roughness of the pattern may be applied to the pattern formed by the pattern forming method of the present invention. As a method for improving the surface roughness of the pattern, for example, a method of treating a resist pattern with a plasma of a hydrogen-containing gas disclosed in WO2014 / 002808A1 can be mentioned. In addition, JP2004-235468, US2010 / 0020297A, JP2009-19969, Proc. of SPIE Vol. 8328 83280N-1 “EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement” may be applied.

[Actinic ray-sensitive or radiation-sensitive resin composition]
Next, the actinic ray-sensitive or radiation-sensitive resin composition (the present resist composition) used in the pattern forming method of the present invention will be described.

(A) Resin The resist composition of the present invention contains a resin whose polarity increases by the action of an acid (a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases).
Resin (hereinafter also referred to as “resin (A)”) whose polarity is increased by the action of an acid and whose solubility in a developer containing an organic solvent is reduced is a resin main chain or side chain, or main chain and side. Resin (hereinafter referred to as “acid-decomposable resin” or “acid-decomposable resin” (hereinafter also referred to as “acid-decomposable group”) that decomposes by the action of an acid to generate an alkali-soluble group on both of the chains. A) ").) Is preferred.
Furthermore, the resin (A) is more preferably a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”). A resin having a monocyclic or polycyclic alicyclic hydrocarbon structure has high hydrophobicity, and it is considered that developability is improved when a region having a low light irradiation intensity of a resist film is developed with an organic developer.

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

Examples of alkali-soluble groups contained in the resin (A) include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, Alkylsulfonyl) (alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, And a group having a tris (alkylsulfonyl) methylene group.
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.

A preferred group as an acid-decomposable group (acid-decomposable group) is a group obtained by substituting a hydrogen atom of these alkali-soluble groups with a group capable of leaving with an acid.
A repeating unit having an acid-decomposable group is also referred to as an acid-decomposable repeating unit.

Examples of the group capable of leaving with an acid (acid leaving group) 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 to} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  In the resin (A), the content of the repeating unit having an acid-decomposable group is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more in all repeating units. In the resin (A), the content of the repeating unit having an acid-decomposable group is preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, in all repeating units. A mol% or less is particularly preferred.

  The resin (A) is at least one selected from the group consisting of repeating units having a partial structure represented by the following general formula (pI) to general formula (pV) and repeating units represented by the following general formula (II-AB). A resin containing seeds is preferred.

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

In 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 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 _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms.

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

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

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

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

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

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

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

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

  Hereinafter, although the specific example of the repeating unit 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 in R ₁₁ ′ and R ₁₂ ′ include a linear or branched alkyl group having 1 to 10 carbon atoms.

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

Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{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).

  In the resin (A), a group that is decomposed by the action of an acid is represented by, for example, a repeating unit having a partial structure represented by the general formula (pI) to the general formula (pV), or a general formula (II-AB). It is contained in at least one repeating unit among the repeating unit and the repeating unit of the copolymerization component described later. The group capable of decomposing by the action of an acid is preferably contained in a repeating unit having a partial structure represented by general formula (pI) to general formula (pV).

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

  In the resin (A), the content of the repeating unit having a partial structure represented by the general formulas (pI) to (pV) is preferably 20 to 70 mol%, more preferably 20 to 50 mol% in all repeating units. More preferably, it is 25 to 40 mol%.

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

  It is preferable that resin (A) contains the repeating unit represented by General formula (3).

In general formula (3),
R ₃₁ represents a hydrogen atom or an alkyl group.
R ₃₂ represents an alkyl group or a cycloalkyl group, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. And a cyclohexyl group.
R ₃₃ represents an atomic group necessary for forming a monocyclic alicyclic hydrocarbon structure together with the carbon atom to which R ₃₂ is bonded. In the alicyclic hydrocarbon structure, a part of carbon atoms constituting the ring may be substituted with a hetero atom or a group having a hetero atom.

The alkyl group for R ₃₁ may have a substituent, and examples of the substituent include a fluorine atom and a hydroxyl group. R ₃₁ preferably represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₃₂ is preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert-butyl group or a cyclohexyl group, and more preferably a methyl group, an ethyl group, an isopropyl group or a tert-butyl group. .
The monocyclic alicyclic hydrocarbon structure formed by R ₃₃ together with the carbon atom is preferably a 3- to 8-membered ring, and more preferably a 5- or 6-membered ring.
In the monocyclic alicyclic hydrocarbon structure formed by R ₃₃ together with the carbon atom, examples of the hetero atom that can form the ring include an oxygen atom and a sulfur atom. Examples of the group having a hetero atom include a carbonyl group and the like. Can be mentioned. However, the group having a hetero atom is preferably not an ester group (ester bond).
The monocyclic alicyclic hydrocarbon structure formed by R ₃₃ together with the carbon atom is preferably formed only from the carbon atom and the hydrogen atom.

  The repeating unit represented by the general formula (3) is preferably a repeating unit represented by the following general formula (3 ′).

In general formula (3 ′), R ₃₁ and R ₃₂ have the same meanings as in general formula (3).
Although the specific example of the repeating unit which has a structure represented by General formula (3) is given below, it is not limited to these.

  The content of the repeating unit having the structure represented by the general formula (3) is preferably 20 to 80 mol% with respect to all repeating units in the resin (A), and preferably 25 to 75 mol%. Is more preferable, and it is still more preferable that it is 30-70 mol%.

  The resin (A) preferably has at least one of the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II).

In formulas (I) and (II),
R ₁ and R ₃ each independently represent a hydrogen atom, a methyl group which may have a substituent, or a group represented by —CH ₂ —R ₁₁ . R ₁₁ represents a monovalent organic group.
R ₂ , R ₄ , R ₅ and R ₆ each independently represents an alkyl group or a cycloalkyl group.
R represents an atomic group necessary for forming an alicyclic structure together with the carbon atom to which R ₂ is bonded.

R ₁ and R ₃ preferably represent a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms and an acyl group having 5 or less carbon atoms, preferably 3 or less carbon atoms. And more preferably a methyl group.
The alkyl group in R ₂ may be linear or branched, and may have a substituent.
The cycloalkyl group in R ₂ may be monocyclic or polycyclic and may have a substituent.
R ₂ is preferably an alkyl group, more preferably an alkyl group having 1 to 10 carbon atoms, still more preferably 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, Examples include t-butyl group. As the alkyl group for R _{2, a} methyl group, an ethyl group, an i-propyl group, and a t-butyl group are preferable.
R represents an atomic group necessary for forming an alicyclic structure together with a carbon atom. The alicyclic structure formed by R together with the carbon atom is preferably a monocyclic alicyclic structure, and the carbon number is preferably 3 to 7, more preferably 5 or 6.

R ₃ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
The alkyl group in R ₄ , R ₅ , and R ₆ may be linear or branched and may have a substituent. As the alkyl group, those having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group are preferable.
The cycloalkyl group in R ₄ , R ₅ , and R ₆ may be monocyclic or polycyclic and may have a substituent. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group or an adamantyl group.
Examples of the substituent that each of the above groups may have include, for example, an alkyl group (1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (2 to 2 carbon atoms). 6) etc. are mentioned, and C8 or less is preferable.

In the general formula (II), R ₄ , R ₅ and R ₆ are preferably alkyl groups, and the total number of carbon atoms of R ₄ , R ₅ and R ₆ is preferably 5 or more, and 6 or more. It is more preferable that it is 7 or more.

The resin (A) is more preferably a resin containing a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II).
Moreover, in another form, it is more preferable that it is resin containing at least 2 types of the repeating unit represented by general formula (I). When two or more repeating units of the general formula (I) are included, the alicyclic structure formed by R together with the carbon atom is a monocyclic alicyclic structure, and the alicyclic structure formed by R together with the carbon atom. It is preferable that both the repeating unit which is a polycyclic alicyclic structure is included. The monocyclic alicyclic structure preferably has 5 to 8 carbon atoms, more preferably 5 or 6 carbon atoms, and particularly preferably 5 carbon atoms. As the polycyclic alicyclic structure, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are preferable.
One type of repeating unit having an acid-decomposable group contained in the resin (A) may be used, or two or more types may be used in combination.

  The content of at least one of the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II) is 20 to 80 with respect to all the repeating units in the resin (A). It is preferably mol%, more preferably 25 to 75 mol%, still more preferably 30 to 70 mol%.

The resin (A) preferably contains a repeating unit having a lactone structure or a sultone (cyclic sulfonate ester) structure.
Any lactone group or sultone group can be used as long as it has a lactone structure or a sultone structure, but it is preferably a 5- to 7-membered lactone structure or a sultone structure, and a 5- to 7-membered lactone A structure in which another ring structure is condensed to form a bicyclo structure or a spiro structure in the structure or sultone structure is preferable. It is more preferable to have a repeating unit having a lactone structure or a sultone structure represented by any of the following general formulas (LC1-1) to (LC1-17), (SL1-1) and (SL1-2). A lactone structure or a sultone structure may be directly bonded to the main chain. Preferred lactone structures or sultone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-8), and more preferably (LC1-4). By using a specific lactone structure or sultone structure, LWR and development defects are improved.

The lactone structure portion or the sultone structure portion 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 2 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferably, they are a C1-C4 alkyl group, a cyano group, and an acid-decomposable group. n ₂ represents an integer of 0-4. When n ₂ 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. .
The resin (A) preferably contains a repeating unit having a lactone structure or a sultone structure represented by the following general formula (III).

In formula (III),
A represents an ester bond (a group represented by —COO—) or an amide bond (a group represented by —CONH—).
When there are a plurality of R _{0 s} , each R ₀ independently represents an alkylene group, a cycloalkylene group, or a combination thereof.
When there are a plurality of Z, each is independently a single bond, ether bond, ester bond, amide bond, urethane bond

Or urea bond

Represents. Here, R represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group each independently.
R ₈ represents a monovalent organic group having a lactone structure or a sultone structure.
n _is the repetition number of the structure represented by -R 0 -Z-, represents an integer of 0 to 2.
R ₇ represents a hydrogen atom, a halogen atom or an alkyl group.
The alkylene group and cycloalkylene group represented by R ₀ may have a substituent.
Z is preferably an ether bond or an ester bond, and particularly preferably an ester bond.

The alkyl group for R ₇ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. The alkylene group of R ₀ , the cycloalkylene group, and the alkyl group in R ₇ may each be substituted. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom and bromine atom, mercapto group, hydroxy group Groups, methoxy groups, ethoxy groups, isopropoxy groups, t-butoxy groups, alkoxy groups such as benzyloxy groups, and acyloxy groups such as acetyloxy groups and propionyloxy groups. R ₇ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
Preferable chain alkylene group in R ₀ is preferably a chain alkylene having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, and a propylene group. A preferable cycloalkylene group is a cycloalkylene group having 3 to 20 carbon atoms, and examples thereof include a cyclohexylene group, a cyclopentylene group, a norbornylene group, and an adamantylene group. In order to exhibit the effect of the present invention, a chain alkylene group is more preferable, and a methylene group is particularly preferable.

The monovalent organic group having a lactone structure or a sultone structure represented by R ₈ is not limited as long as it has a lactone structure or a sultone structure, and the general formula (LC1-1) described above as a specific example A lactone structure or a sultone structure represented by ~ (LC1-17), (SL1-1) and (SL1-2) is exemplified, and among these, the structure represented by (LC1-4) is particularly preferable. Further, n ₂ in (LC1-1) to (LC1-17), (SL1-1) and (SL1-2) is more preferably 2 or less.
R ₈ is preferably a monovalent organic group having an unsubstituted lactone structure or sultone structure, or a monovalent organic group having a lactone structure or sultone structure having a methyl group, a cyano group or an alkoxycarbonyl group as a substituent. A monovalent organic group having a lactone structure (cyanolactone) or a sultone structure (cyanosultone) having a cyano group as a substituent is more preferable.
In the general formula (III), n is preferably 0 or 1.

  The content of the repeating unit represented by the general formula (III) is preferably 15 to 60 mol%, more preferably 20 to 20% by total with respect to all repeating units in the resin (A) when a plurality of types are contained. 60 mol%, more preferably 30-50 mol%.

  The resin (A) may also contain a repeating unit having the above-mentioned lactone structure or sultone structure in addition to the unit represented by the general formula (III).

The repeating unit having a lactone group or a sultone group 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 optical isomer is mainly used, the optical purity (ee) thereof is preferably 90% or more, more preferably 95% or more.
The content of the repeating unit having a lactone structure or a sultone structure other than the repeating unit represented by the general formula (III) is 15 to 60 mol% in total with respect to all repeating units in the resin when a plurality of types are contained. Is more preferable, more preferably 20 to 50 mol%, still more preferably 30 to 50 mol%.
In order to enhance the effect of the present invention, two or more lactones or sultone repeating units selected from general formula (III) can be used in combination. When using together, it is preferable to select and use 2 or more types from the lactone or sultone repeating unit in which n is 0 in general formula (III).

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

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. has a group represented by the general formula (VII) (e.g., represents a group R ₅ in -COOR ₅ is a represented by the general formula (VIIa) ~ (VIId)) , or the following general formula (AIIa) ~ ( Examples thereof include a repeating unit represented by AIId).

In general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
R _<2c > -R < _4c > is synonymous with R < _2c > -R < _4c > in general formula (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.

  In the resin (A), 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 5 to 20 mol% in all repeating units. It is.

The resin (A) may further contain a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.
In the resin (A), the content of the repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability is preferably 1 to 40 mol%, more preferably 5 to 30 mol% in all repeating units, 5-20 mol% is still more preferable.

Resin (A) can contain repeating units derived from various monomers for the purpose of adjusting various properties in addition to the repeating units described above. Examples of such monomers include acrylics. Examples thereof include compounds having one addition polymerizable unsaturated bond selected from acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters and the like.
In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating units may be copolymerized.

  The content of the repeating unit derived from the monomer in the resin (A) can also be set as appropriate, but is generally a partial structure represented by the general formulas (pI) to (pV). Is preferably 99 mol% or less, more preferably 90 mol% or less, still more preferably 80 mol%, based on the total number of moles of the repeating unit having the above formula and the repeating unit represented by formula (II-AB). It is as follows.

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

  As resin (A), Preferably, all the repeating units are comprised by the (meth) acrylate type repeating unit. 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, The acrylate repeating unit is preferably 50 mol% or less of the entire repeating unit.

  Resin (A) includes at least a (meth) acrylate repeating unit having a lactone ring, a (meth) acrylate repeating unit having an organic group substituted with at least one of a hydroxyl group and a cyano group, and an acid-decomposable group It is preferable that it is a copolymer which has three types of repeating units of the (meth) acrylate type repeating unit which has this.

  Preferably, the repeating unit having a partial structure represented by general formulas (pI) to (pV) is 20 to 50 mol%, the repeating unit having a lactone structure is 20 to 50 mol%, and the alicyclic hydrocarbon structure is substituted with a polar group It is a ternary copolymer containing 5 to 30% of repeating units having 4 or 30%, or a quaternary copolymer containing 0 to 20% of other repeating units.

  Preferred resins (A) include, for example, the resins described in paragraphs <0152> to <0158> of JP-A-2008-309878, but the present invention is not limited thereto.

  The resin (A) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate; amide solvents such as dimethylformamide and dimethylacetamide; And a solvent for dissolving the resist composition of the present invention, such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone. More preferably, polymerization is performed using the same solvent as the solvent used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As the 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.
Purification is a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water washing and an appropriate solvent; 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 dropping resin solution into poor solvent; purification in solid state such as washing filtered resin slurry with poor solvent The usual method such as method; can be applied.

The weight average molecular weight (Mw) of the resin (A) is preferably 1,000 to 200,000, more preferably 1,000 to 20,000, more preferably as a polystyrene converted value by GPC (Gel Permeation Chromatography) method. Preferably it is 1,000-15,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, and viscosity is increased and film formability is deteriorated. Can be prevented.
The dispersity (molecular weight distribution), which is the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in the resin (A), is usually 1 to 5, preferably 1 to 3, and more preferably Preferably those in the range of 1.2 to 3.0, particularly preferably 1.2 to 2.0 are used. 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.
The weight average molecular weight and the number average molecular weight in this specification are HLC-8120 (manufactured by Tosoh Corporation), and TSK gel Multipore HXL-M (manufactured by Tosoh Corporation, 7.8 mm ID × 30.0 cm) is used as a column. And THF (tetrahydrofuran) as an eluent.

As for the compounding quantity of resin (A) in the whole resist composition of this invention, 50-99.9 mass% is preferable in a total solid, More preferably, it is 60-99.0 mass%.
In the present invention, the resin (A) may be used alone or in combination.

  The resin (A), preferably the resist composition of the present invention, preferably contains no fluorine atom and no silicon atom from the viewpoint of compatibility with the topcoat composition.

(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 (hereinafter referred to as “acid generator”, “photoacid generator”). Or “(B) component”).
Examples of such a photoacid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an actinic ray used in a microresist or the like. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

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

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

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

The acid generator contained in the composition of the present invention is preferably a compound that generates an acid having a cyclic structure upon irradiation with actinic rays or radiation. As the cyclic structure, a monocyclic or polycyclic alicyclic group is preferable, and a polycyclic alicyclic group is more preferable. The carbon atom constituting the ring skeleton of the alicyclic group preferably does not contain a carbonyl carbon.
As an acid generator which the composition of this invention contains, it is also called the compound (henceforth a "specific acid generator" hereafter) which generate | occur | produces an acid by irradiation of the actinic ray or radiation represented by following General formula (3). ) Can be preferably mentioned.

(Anion)
In general formula (3),
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₄ and R ₅ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and when there are a plurality of R ₄ and R ₅ , R ₄ and R ₅ are the same But it can be different.
L represents a divalent linking group, and when there are a plurality of L, L may be the same or different.
W represents an organic group containing a cyclic structure.
o represents an integer of 1 to 3. p represents an integer of 0 to 10. q represents an integer of 0 to 10.

Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group.
Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Xf is more preferably a fluorine atom or CF ₃ . In particular, it is preferable that both Xf are fluorine atoms.

R ₄ and R ₅ each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and when there are a plurality of R ₄ and R ₅ , R ₄ and R ₅ are the same But it can be different.
The alkyl group as R ₄ and R ₅ may have a substituent, and preferably has 1 to 4 carbon atoms. R ₄ and R ₅ are preferably a hydrogen atom.
Specific examples and preferred embodiments of the alkyl group substituted with at least one fluorine atom of R ₄ and R ₅ are the same as the specific examples and preferred embodiments of Xf in formula (3).

L represents a divalent linking group, and when there are a plurality of L, L may be the same or different.
Examples of the divalent linking group include —COO — (— C (═O) —O—), —OCO—, —CONH—, —NHCO—, —CO—, —O—, —S—, — SO—, —SO ₂ —, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 10 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), or a combination thereof And divalent linking groups. Among them, -COO -, - OCO -, - CONH -, - NHCO -, - CO -, - O -, - SO 2 -, - COO- alkylene group -, - OCO- alkylene group -, - CONH- alkylene group - or -NHCO- alkylene group - are preferred, -COO -, - OCO -, - CONH -, - SO 2 -, - COO- alkylene group - or -OCO- alkylene group - is more preferable.

W represents an organic group containing a cyclic structure. Of these, a cyclic organic group is preferable.
Examples of the cyclic organic group include an alicyclic group, an aryl group, and a heterocyclic group.
The alicyclic group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include polycyclic cycloalkyl groups such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Among them, an alicyclic group having a bulky structure having 7 or more carbon atoms such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, a diamantyl group, and an adamantyl group is formed by PEB (heating after exposure). ) From the viewpoint of suppressing diffusibility in the film and improving MEEF (Mask Error Enhancement Factor).

The aryl group may be monocyclic or polycyclic. Examples of the aryl group include a phenyl group, a naphthyl group, a phenanthryl group, and an anthryl group. Among these, a naphthyl group having a relatively low light absorbance at 193 nm is preferable.
The heterocyclic group may be monocyclic or polycyclic, but the polycyclic group can further suppress acid diffusion. Moreover, the heterocyclic group may have aromaticity or may not have aromaticity. Examples of the heterocyclic ring having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Examples of the heterocyclic ring that does not have aromaticity include a tetrahydropyran ring, a lactone ring, a sultone ring, and a decahydroisoquinoline ring. As the heterocyclic ring in the heterocyclic group, a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring is particularly preferable. Examples of the lactone ring and sultone ring include the lactone structure and sultone structure exemplified in the aforementioned resin.

  The cyclic organic group may have a substituent. Examples of the substituent include an alkyl group (which may be linear or branched, preferably 1 to 12 carbon atoms), and a cycloalkyl group (monocyclic, polycyclic or spirocyclic). Well, preferably having 3 to 20 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), hydroxyl group, alkoxy group, ester group, amide group, urethane group, ureido group, thioether group, sulfonamide group, and sulfonic acid An ester group is mentioned. The carbon constituting the cyclic organic group (carbon contributing to ring formation) may be a carbonyl carbon.

o represents an integer of 1 to 3. p represents an integer of 0 to 10. q represents an integer of 0 to 10.
In one embodiment, o in the general formula (3) is an integer of 1 to 3, p is an integer of 1 to 10, and q is preferably 0. Xf is preferably a fluorine atom, R ₄ and R ₅ are preferably both hydrogen atoms, and W is preferably a polycyclic hydrocarbon group. o is more preferably 1 or 2, and still more preferably 1. p is more preferably an integer of 1 to 3, further preferably 1 or 2, and particularly preferably 1. W is more preferably a polycyclic cycloalkyl group, and further preferably an adamantyl group or a diamantyl group.

(Cation)
In the general formula (3), X ⁺ represents a cation.
X ⁺ is not particularly limited as long as it is a cation, and preferred embodiments include, for example, cations (parts other than Z ⁻ ) in the general formula (ZI), (ZII) or (ZIII) described later.

(Preferred embodiment)
As a suitable aspect of a specific acid generator, the compound represented by the following general formula (ZI), (ZII) or (ZIII) is mentioned, for example.

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R _{201, R 202} and _{R 203} is generally from 1 to 30, preferably 1 to 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. Examples of the group formed by combining two of R _{201 to} R ₂₀₃ include an alkylene group (eg, butylene group, pentylene group).
Z ⁻ represents an anion in the general formula (3), and specifically represents the following anion.

Examples of the organic group represented by R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the corresponding groups in the compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described later. Can be mentioned.
In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, at least one of R _{201 to} R ₂₀₃ of the compound represented by the general formula (ZI) is a single bond or at least one of R _{201 to} R ₂₀₃ of another compound represented by the general formula (ZI) It may be a compound having a structure bonded through a linking group.

  Further preferred examples of the (ZI) component include compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described below.

First, the compound (ZI-1) will be described.
The compound (ZI-1) is an arylsulfonium compound in which at least one of R _{201 to} R _{203 in} the general formula (ZI) is an aryl group, that is, 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 a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene 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 or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (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.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group not containing an 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 or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

As the alkyl group and cycloalkyl group of R _{201 to} R ₂₀₃ , a linear or branched alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Next, the compound (ZI-3) will be described.
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 are each independently a hydrogen atom, alkyl group, cycloalkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, alkylcarbonyloxy group, cycloalkylcarbonyloxy group, halogen atom, hydroxyl group Represents a nitro group, an alkylthio group or an arylthio group.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.

Any two or more of R _{1c to} R _5c , R _5c and R _6c , R _6c and R _7c , R _5c and R _x , and R _x and R _y may be bonded to form a ring structure. In addition, this ring structure may contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the ring structure include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, or a polycyclic fused ring formed by combining two or more of these rings. Examples of the ring structure include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.

Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.
The group formed by combining R _5c and R _6c and R _5c and R _x is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group. .
Zc ^- represents an anion of the general formula (3), specifically, as described above.

Specific examples of the alkoxy group in the alkoxycarbonyl group as R _1c to R _5c are the same as specific examples of the alkoxy group as the _R 1c _{to R 5c.}
Specific examples of the alkyl group in the alkylcarbonyloxy group and alkylthio group as R _1c to R _5c are the same as specific examples of the alkyl group of the _R 1c _{to R 5c.}
Specific examples of the cycloalkyl group in the cycloalkyl carbonyl group as R _1c to R _5c are the same as specific examples of the cycloalkyl group of the _R 1c _{to R 5c.}
Specific examples of the aryl group in the aryloxy group and arylthio group as R _1c to R _5c are the same as specific examples of the aryl group of the _R 1c _{to R 5c.}

  Examples of the cation in the compound (ZI-2) or (ZI-3) in the present invention include cations described in paragraph <0036> and thereafter of US Patent Application Publication No. 2012/0076996.

Next, the compound (ZI-4) will be described.
The compound (ZI-4) is represented by the following general formula (ZI-4).

In general formula (ZI-4),
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a cycloalkyl group. These groups may have a substituent.
R ₁₄ is independently a group having a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a cycloalkyl group, when a plurality of R ₁₄ are present. Represents. These groups may have a substituent.
R ₁₅ each independently represents an alkyl group, a cycloalkyl group or a naphthyl group. These groups may have a substituent. Two R ₁₅ may be bonded to each other to form a ring. When two R ₁₅ 's are bonded to each other to form a ring, the ring skeleton may contain a hetero atom such as an oxygen atom or a nitrogen atom. In one embodiment, it is preferred that two R ₁₅ are alkylene groups and are bonded to each other to form a ring structure.
l represents an integer of 0-2.
r represents an integer of 0 to 8.
Z ⁻ represents an anion in the general formula (3), specifically, as described above.

In the general formula (ZI-4), the alkyl group of R ₁₃ , R ₁₄ and R ₁₅ is linear or branched and preferably has 1 to 10 carbon atoms, and is preferably a methyl group, an ethyl group, n -A butyl group, a t-butyl group, etc. are preferable.
Examples of the cation of the compound represented by the general formula (ZI-4) in the present invention include paragraphs <0121>, <0123>, <0124>, and JP2011-76056A in JP2010-256842A. The cations described in paragraphs <0127>, <0129>, <0130>, etc.

Next, general formulas (ZII) and (ZIII) will be described.
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.
The aryl group for R _{204 to} R ₂₀₇ is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group of R _{204 to} R ₂₀₇ may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
The alkyl group and cycloalkyl group in R _{204 to} R ₂₀₇ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

The aryl group, alkyl group, and cycloalkyl group of R _{204 to} R ₂₀₇ may have a substituent. Examples of the substituent that the aryl group, alkyl group, and cycloalkyl group of R _{204 to} R ₂₀₇ may have include, for example, an alkyl group (eg, having 1 to 15 carbon atoms) and a cycloalkyl group (eg, having 3 to 15 carbon atoms). ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.
Z ⁻ represents an anion in the general formula (3), specifically, as described above.

  An acid generator can be used individually by 1 type or in combination of 2 or more types.

The content of the acid generator in the resist composition of the present invention (when a plurality of types of acid generators are present (the same applies hereinafter)) is 16 on the basis of the total solid content of the resist composition of the present invention. .5% by mass or more. Thereby, CDU and LER are excellent because the amount of generated acid increases.
From the reason that CDU and LER are more excellent, the content of the acid generator is preferably 17.0 to 35.0% by mass based on the total solid content of the resist composition of the present invention, and 20.0 to 28. 0 mass% is more preferable, and more than 20.0 mass% and 28.0 mass% or less are still more preferable.

(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, alkoxypropion. Examples thereof include organic solvents such as alkyl acid, cyclic lactone having 4 to 10 carbon atoms, monoketone compound having 4 to 10 carbon atoms and optionally containing a ring, alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.

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

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

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

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include, for example, 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 Examples include 2- (2-ethoxyethoxy) ethyl, propylene carbonate, butyl butanoate, isoamyl acetate, and methyl 2-hydroxyisobutyrate.
In this invention, the said solvent may be used independently and may use 2 or more types together.

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

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

(D) Hydrophobic resin The resist composition of the present invention may contain (D) a hydrophobic resin. As the hydrophobic resin, for example, a resin (X) described later which may be contained in the topcoat composition can be suitably used. Further, for example, “[4] Hydrophobic resin (D)” described in paragraphs <0389> to <0474> of JP-A-2014-149409 is also preferable.

The weight average molecular weight of the hydrophobic resin (D) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and still more preferably 2,000 to 15,000. is there.
In addition, the hydrophobic resin (D) may be used alone or in combination.
The content of the hydrophobic resin (D) in the composition is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, based on the total solid content in the resist composition of the present invention. 0.1-7 mass% is still more preferable.

(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 (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring.

Regarding the alkyl group, the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.
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. ] Undec-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.

  Moreover, as a basic compound, what is described as a basic compound which the composition for upper layer film formation (topcoat composition) mentioned later may contain can also be used suitably.

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 on the basis of solid content of the resist composition of this invention, Preferably it is 0.01-5 mass%.

  The use ratio of the photoacid generator and the basic compound in the resist composition is preferably photoacid generator / basic compound (molar ratio) = 2.5 to 300. That is, 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 photoacid generator / basic compound (molar ratio) is more preferably 5.0 to 200, and 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 (Dainippon Ink Chemical Co., Ltd.), 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 Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M , EF135M, EF351, 352, EF801, EF802, EF 01 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208G, 218G, 230G, 204D, 208D, 212D, 218, 222D (manufactured by Neos) Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the 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) Onium carboxylate The resist composition of the present invention may contain (G) an onium carboxylate. 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 (G) carboxylic acid onium salt does not contain an aromatic group and a carbon-carbon double bond. As the particularly preferred anion moiety, a linear, branched or cyclic (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. As a result, transparency with respect to light of 220 nm or less is ensured, sensitivity and resolving power are improved, and density dependency and exposure margin are improved.

  Fluorine-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.

  (G) 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, more preferably, based on the total solid content of the resist composition. 1 to 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 a phenol compound having a molecular weight of 1000 or less can be obtained, for example, by referring to the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. 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 include, but are not limited to, dicarboxylic acids.

[Composition for forming upper layer film (topcoat composition)]
Next, an upper layer film forming composition (top coat composition) for forming an upper layer film (top coat) used in the pattern forming method of the present invention will be described.
In the pattern forming method of the present invention, when immersion exposure is performed, the top coat is formed to prevent the immersion liquid from coming into direct contact with the resist film, so that the immersion liquid penetrates into the resist film and the resist film. It can be expected that the resist performance deterioration due to the elution of the components into the immersion liquid is suppressed, and further, the effect of preventing the lens contamination of the exposure apparatus due to the elution components into the immersion liquid can be expected.

  The topcoat composition used in the pattern forming method of the present invention is preferably a composition containing a resin (X) and a solvent described later in order to form the topcoat composition uniformly on the resist film.

<Solvent>
In order to form a good pattern without dissolving the resist film, the topcoat composition in the present invention preferably contains a solvent that does not dissolve the resist film, and uses a solvent having a component different from that of the organic developer. It is more preferable.
Further, from the viewpoint of preventing elution into the immersion liquid, it is preferable that the solubility in the immersion liquid is low, and it is more preferable that the solubility in water is low. In the present specification, “low solubility in immersion liquid” indicates that the immersion liquid is insoluble. Similarly, “low solubility in water” indicates water insolubility. In addition, from the viewpoint of volatility and coatability, the boiling point of the solvent is preferably 90 ° C to 200 ° C.
The low solubility in the immersion liquid means that, for example, the solubility in water, the topcoat composition is applied on a silicon wafer, dried and a film is formed, and then the film is formed in pure water at 23 ° C. It means that the reduction rate of the film thickness after dipping for 10 minutes and drying is within 3% of the initial film thickness (typically 50 nm).
In the present invention, from the viewpoint of uniformly applying the top coat, the solid content concentration is 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and most preferably 1 to 10% by mass. Use solvent.

  The solvent that can be used is not particularly limited as long as it dissolves the resin (X) described later and does not dissolve the resist film. For example, alcohol solvents, ether solvents, ester solvents, fluorine solvents, hydrocarbons Suitable examples thereof include non-fluorinated alcohol solvents. Thereby, the insolubility with respect to a resist film improves further, and when a topcoat composition is apply | coated on a resist film, a topcoat can be formed more uniformly, without melt | dissolving a resist film. The viscosity of the solvent is preferably 5 cP (centipoise) or less, more preferably 3 cP or less, still more preferably 2 cP or less, and particularly preferably 1 cP or less. The centipoise to Pascal second can be converted by the following formula: 1000 cP = 1 Pa · s.

The alcohol solvent is preferably a monohydric alcohol, more preferably a monohydric alcohol having 4 to 8 carbon atoms, from the viewpoint of applicability. As the monohydric alcohol having 4 to 8 carbon atoms, a linear, branched or cyclic alcohol can be used, but a linear or branched alcohol is preferable. Examples of such alcohol solvents include 1-butanol, 2-butanol, 3-methyl-1-butanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, isobutyl alcohol, 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 Alcohols such as octanol; glycols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether Glycol ethers such as triethylene glycol monoethyl ether and methoxymethylbutanol can be used. Among them, alcohol and glycol ether are preferable, and 1-butanol, 1-hexanol, 1-pentanol, and 3-methyl-1 are preferable. -Butanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, and propylene glycol monomethyl ether are more preferable.
Examples of the ether solvent include dioxane, tetrahydrofuran, isoamyl ether and the like in addition to the glycol ether solvent. Of the ester solvents, ether solvents having a branched structure are preferable.
Examples of ester solvents include methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate (n-butyl acetate), pentyl acetate, hexyl acetate, isoamyl acetate, butyl propionate (n-butyl propionate), butyl butyrate, butyric acid Isobutyl, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate , Methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, methyl 2-hydroxyisobutyrate, isobutyl isobutyrate, Propionic acid butyl and the like. Of the ester solvents, ester solvents having a branched structure are preferable.

Examples of the fluorine-based solvent include 2,2,3,3,4,4-hexafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol. 2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol, 2,2,3,3,4,4-hexafluoro-1,5-pentanediol, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, 2,2,3,3,4,4,5,5,6,6,7,7- Dodecafluoro-1,8-octanediol, 2-fluoroanisole, 2,3-difluoroanisole, perfluorohexane, perfluoroheptane, perfluoro-2-pentanone, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, perful B tributylamine, include perfluoro tetrapentyl amine or the like, and among this, can be preferably used a fluorinated alcohol or fluorinated hydrocarbon solvent.
Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene, xylene, and anisole; n-heptane, n-nonane, n-octane, n-decane, 2-methylheptane, 3-methylheptane, 3 , 3-dimethylhexane, aliphatic hydrocarbon solvents such as 2,3,4-trimethylpentane; and the like.

These solvents may be used alone or in combination.
The topcoat composition may contain a solvent other than the above. By mixing a solvent other than the above, the solubility in the resist film, the solubility of the resin in the topcoat composition, the elution characteristics from the resist film, and the like can be appropriately adjusted.

<Resin (X)>
The resin (X) in the topcoat composition is preferably transparent in the exposure light source used because light reaches the resist film through the topcoat during exposure. When used for ArF immersion exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

The resin (X) preferably has at least one of “fluorine atom”, “silicon atom”, and “CH ₃ partial structure contained in the side chain portion of the resin”, and preferably has two or more types. It is more preferable. Further, it is preferably a water-insoluble resin (hydrophobic resin).

  When the resin (X) has a fluorine atom and / or a silicon atom, the fluorine atom and / or the silicon atom may be contained in the main chain of the resin (X) or may be substituted with a side chain.

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

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

In general formulas (F2) to (F3),
R _{57 to} R ₆₄ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ and R _{62 to} R ₆₄ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having 1 to 4 carbon atoms). R _{57 to} R ₆₁ are preferably all fluorine atoms. R ₆₂ and R ₆₃ 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 more preferably a perfluoroalkyl group having 1 to 4 carbon atoms. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoroethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 , 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.

  When the resin (X) has a silicon atom, the resin (X) 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.

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

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

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

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

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

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

Hereinafter, although the specific example of the repeating unit represented by general formula (CI) is shown, it is not limited to this. X represents a hydrogen atom, —CH ₃ , —F, or —CF ₃ .

Further, as described above, the resin (X) preferably includes a CH ₃ partial structure in the side chain portion. The resin (X) preferably includes a repeating unit having at least one CH ₃ partial structure in the side chain portion, more preferably includes a repeating unit having at least two CH ₃ partial structures in the side chain portion. More preferably, the chain portion contains a repeating unit having at least three CH ₃ partial structures.
Here, the CH ₃ partial structure of the side chain moiety in the resin (X) (hereinafter also simply referred to as “side chain CH ₃ partial structure”) has a CH ₃ partial structure of an ethyl group, a propyl group or the like. It is included.
On the other hand, a methyl group directly bonded to the main chain of the resin (X) (for example, an α-methyl group of a repeating unit having a methacrylic acid structure) causes the uneven distribution of the surface of the resin (X) due to the influence of the main chain. Since the contribution is small, it is not included in the CH ₃ partial structure in the present invention.

More specifically, the resin (X) includes a repeating unit derived from a monomer having a polymerizable moiety having a carbon-carbon double bond, such as a repeating unit represented by the following general formula (M). In the case where R _{11 to} R ₁₄ are CH ₃ “as is”, the CH ₃ is not included in the CH ₃ partial structure of the side chain moiety in the present invention.
Meanwhile, CH ₃ partial structure exists through some atoms from C-C backbone, and those falling under CH ₃ partial structures in the present invention. For example, when R ₁₁ is an ethyl group (CH ₂ CH ₃ ), it is assumed that it has “one” CH ₃ partial structure in the present invention.

In the general formula (M),
R < ₁₁ > -R < ₁₄ > represents a side chain part each independently.
Examples of R _{11 to} R _{14 in the} side chain portion include a hydrogen atom and a monovalent organic group.
Examples of the monovalent organic group for R _{11 to} R ₁₄ include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, and a cycloalkylaminocarbonyl. Group, an arylaminocarbonyl group, and the like, and these groups may further have a substituent.

The resin (X) is preferably a resin having a repeating unit having a CH ₃ partial structure in the side chain portion. As such a repeating unit, the repeating unit represented by the following general formula (II), and the following It is more preferable to have at least one repeating unit (x) among the repeating units represented by the general formula (III). In particular, when KrF, EUV, or electron beam (EB) is used as the exposure light source, the resin (X) can suitably contain a repeating unit represented by the general formula (III).

  Hereinafter, the repeating unit represented by formula (II) will be described in detail.

In the general formula _{(II), X b1} represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom, _{R 2} has one or more CH ₃ partial structure represents an organic group.

The alkyl group of _Xb1 preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a methyl group is preferable.
X _b1 is preferably a hydrogen atom or a methyl group.

Examples of R ₂ include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, and an aralkyl group having one or more CH ₃ partial structures. The above cycloalkyl group, alkenyl group, cycloalkenyl group, aryl group and aralkyl group may further have an alkyl group as a substituent.
R ₂ is preferably an alkyl group or an alkyl-substituted cycloalkyl group having one or more CH ₃ partial structures.
The acid-stable organic group having one or more CH ₃ partial structures as R ₂ preferably has 2 or more and 10 or less CH ₃ partial structures, and more preferably 2 or more and 8 or less.

The alkyl group having one or more CH ₃ partial structures in R ₂ is preferably a branched alkyl group having 3 to 20 carbon atoms. Specific examples of preferable alkyl groups include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5- Examples thereof include a dimethyl-3-heptyl group and 2,3,5,7-tetramethyl-4-heptyl group. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, a 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group is there.

The cycloalkyl group having one or more CH ₃ partial structures in R ₂ 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. 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. More preferably, they are a norbornyl group, a cyclopentyl group, and a cyclohexyl group.
The alkenyl group having one or more CH ₃ partial structures in R ₂ is preferably a linear or branched alkenyl group having 1 to 20 carbon atoms, and more preferably a branched alkenyl group.
The aryl group having one or more CH ₃ partial structures in R ₂ is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group and a naphthyl group. is there.
The aralkyl group having one or more CH ₃ partial structures in R ₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

Specific examples of the hydrocarbon group having two or more CH ₃ partial structures in R ₂ include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2-methyl-3-butyl. Group, 3-hexyl group, 2,3-dimethyl-2-butyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group, Examples include 3,5-dimethylcyclohexyl group, 3,5-ditert-butylcyclohexyl group, 4-isopropylcyclohexyl group, 4-t-butylcyclohexyl group, and isobornyl group. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2,3-dimethyl-2-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5 , 7-tetramethyl-4-heptyl group, 3,5-dimethylcyclohexyl group, 3,5-ditert-butylcyclohexyl group, 4-isopropylcyclohexyl group, 4-t-butylcyclohexyl group and isobornyl group.

  Preferred specific examples of the repeating unit represented by the general formula (II) are shown below. The present invention is not limited to this.

  The repeating unit represented by the general formula (II) is preferably an acid-stable (non-acid-decomposable) repeating unit. Specifically, the repeating unit is decomposed by the action of an acid to form a polar group (alkali-soluble). It is preferable that it is a repeating unit which does not have the group which produces | generates group.

  Hereinafter, the repeating unit represented by formula (III) will be described in detail.

In the above general formula (III), X _b2 represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom, R ₃ represents an acid-stable organic group having one or more CH ₃ partial structures, n represents an integer of 1 to 5.

The alkyl group of _Xb2 preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom is preferable.
X _b2 is preferably a hydrogen atom.

Since R ₃ is an organic group that is stable against an acid, it is preferably an organic group that does not have a group that decomposes by the action of an acid to generate a polar group (alkali-soluble group).

R ₃ includes an alkyl group having one or more CH ₃ partial structures.
The acid-stable organic group having one or more CH ₃ partial structures as R ₃ preferably has 1 or more and 10 or less CH ₃ partial structures, more preferably 1 or more and 8 or less, More preferably, it is 1 or more and 4 or less.

The alkyl group having one or more CH ₃ partial structures in R ₃ is preferably a branched alkyl group having 3 to 20 carbon atoms. Specific examples of preferable alkyl groups include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5- Examples thereof include a dimethyl-3-heptyl group and 2,3,5,7-tetramethyl-4-heptyl group. More preferably, an isobutyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, a 3-methyl-4-hexyl group, a 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group is there.

Specific examples of the alkyl group having two or more CH ₃ partial structures in R ₃ include isopropyl group, isobutyl group, t-butyl group, 3-pentyl group, 2,3-dimethylbutyl group, 2-methyl-3-butyl group, 3-hexyl group, 2-methyl-3-pentyl group, 3-methyl-4-hexyl group, 3,5-dimethyl-4-pentyl group, isooctyl group, 2,4, Examples include 4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3,5,7-tetramethyl-4-heptyl group, and the like. . More preferably, it has more preferably 5 to 20 carbon atoms, and an isopropyl group, a t-butyl group, a 2-methyl-3-butyl group, a 2-methyl-3-pentyl group, and a 3-methyl-4-hexyl group. 3,5-dimethyl-4-pentyl group, 2,4,4-trimethylpentyl group, 2-ethylhexyl group, 2,6-dimethylheptyl group, 1,5-dimethyl-3-heptyl group, 2,3, 5,7-tetramethyl-4-heptyl group and 2,6-dimethylheptyl group.

  n represents an integer of 1 to 5, more preferably an integer of 1 to 3, and still more preferably 1 or 2.

  Preferred specific examples of the repeating unit represented by the general formula (III) are shown below. The present invention is not limited to this.

  The repeating unit represented by the general formula (III) is preferably an acid-stable (non-acid-decomposable) repeating unit. Specifically, it is decomposed by the action of an acid to polar groups (alkali-soluble groups). It is preferable that it is a repeating unit which does not have the group which produces | generates.

In the case where the resin (X) contains a CH ₃ partial structure in the side chain portion, and particularly when it does not have a fluorine atom and a silicon atom, the repeating unit represented by the general formula (II) and the general formula The content of at least one repeating unit (x) among the repeating units represented by (III) is, for example, 20 mol% or more, and 30 mol% or more with respect to all repeating units of the resin (X). Preferably, it is 90 mol% or more, more preferably 95 mol% or more. An upper limit is not specifically limited, For example, 100 mol% or less is mentioned.

  As resin (X), you may contain the repeating unit (d) derived from the monomer which has an alkali-soluble group. Thereby, the solubility with respect to immersion liquid and the solubility with respect to a coating solvent are controllable. Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having

The monomer having an alkali-soluble group is preferably a monomer having an acid dissociation constant pKa of 4 or more, more preferably a monomer having a pKa of 4 to 13, and most preferably a monomer having a pKa of 8 to 13. By containing a monomer having a pKa of 4 or more, swelling during negative-type and positive-type development is suppressed, and not only good developability for an organic developer but also good when an alkali developer is used. Developability is obtained.
Note that the acid dissociation constant pKa in this specification indicates a value obtained by calculation using the software package 1 (described later), although details will be described later.
The monomer having a pKa of 4 or more is not particularly limited, and examples thereof include monomers having an acid group (alkali-soluble group) such as a phenolic hydroxyl group, a sulfonamide group, —COCH ₂ CO—, a fluoroalcohol group, and a carboxylic acid group. Can be mentioned. In particular, a monomer containing a fluoroalcohol group is preferred. The fluoroalcohol group is a fluoroalkyl group substituted with at least one hydroxyl group, preferably having 1 to 10 carbon atoms, more preferably having 1 to 5 carbon atoms. Specific examples of the fluoroalcohol group include, for example, —CF ₂ OH, —CH ₂ CF ₂ OH, —CH ₂ CF ₂ CF ₂ OH, —C (CF ₃ ) ₂ OH, —CF ₂ CF (CF ₃ ) OH. , —CH ₂ C (CF ₃ ) ₂ OH, and the like. Particularly preferred as the fluoroalcohol group is a hexafluoroisopropanol group.

  The total amount of repeating units derived from the monomer having an alkali-soluble group in the resin (X) is preferably 0 to 90 mol%, more preferably 0 to 80 mol, based on all repeating units constituting the resin (X). It is mol%, More preferably, it is 0-70 mol%.

  The monomer having an alkali-soluble group may contain only one acid group or two or more acid groups. The repeating unit derived from this monomer preferably has two or more acid groups per repeating unit, more preferably 2 to 5 acid groups, and 2 to 3 acid groups. It is particularly preferred.

  Specific examples of the repeating unit derived from the monomer having an alkali-soluble group include, but are not limited to, the examples described in paragraphs <0278> to <0287> of JP-A-2008-309878.

  The resin (X) may be any resin selected from (X-1) to (X-8) described in paragraph <0288> of JP-A-2008-309878. As one.

The resin (X) is preferably a solid at room temperature (25 ° C.). Furthermore, the glass transition temperature (Tg) is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 80 ° C. or higher.
In addition, as an upper limit of Tg of resin (X), 250 degrees C or less is preferable, for example.

The resin (X) preferably has a repeating unit having a monocyclic or polycyclic cycloalkyl group. The monocyclic or polycyclic cycloalkyl group may be contained in either the main chain or the side chain of the repeating unit. More preferably a repeating unit having both a monocyclic or polycyclic cycloalkyl group and CH ₃ partial structure, both monocyclic or polycyclic cycloalkyl group and CH ₃ moiety side chains The repeating unit contained in is more preferred.

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

  The resin (X) is preferably insoluble in an immersion liquid (preferably water) and soluble in an organic developer. From the viewpoint of being able to develop and peel off using an alkali developer, the resin (X) is preferably soluble in an alkali developer.

When resin (X) has a silicon atom, 2-50 mass% is preferable with respect to the molecular weight of resin (X), and, as for content of a silicon atom, 2-30 mass% is more preferable. Moreover, it is preferable that it is 10-100 mass% in resin (X), and, as for the repeating unit containing a silicon atom, it is more preferable that it is 20-100 mass%.
When resin (X) has a fluorine atom, 5-80 mass% is preferable with respect to the molecular weight of resin (X), and, as for content of a fluorine atom, 10-80 mass% is more preferable. Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in resin (X), and it is more preferable that it is 30-100 mass%.

On the other hand, in particular, when the resin (X) contains a CH ₃ partial structure in the side chain portion, a form in which the resin (X) does not substantially contain a fluorine atom is also preferable. In this case, specifically, the fluorine atom Is preferably 0 to 20 mol%, more preferably 0 to 10 mol%, still more preferably 0 to 5 mol%, and more preferably 0 to 3 mol% with respect to all repeating units in the resin (X). Mole% is particularly preferred, ideally 0 mole%, i.e. it does not contain fluorine atoms.
Moreover, it is preferable that resin (X) is substantially comprised only by the repeating unit comprised only by the atom chosen from a carbon atom, an oxygen atom, a hydrogen atom, a nitrogen atom, and a sulfur atom. More specifically, the repeating unit composed only of atoms selected from a carbon atom, an oxygen atom, a hydrogen atom, a nitrogen atom, and a sulfur atom is 95 mol% or more in all the repeating units of the resin (X). Preferably, it is 97 mol% or more, more preferably 99 mol% or more, and ideally 100 mol%.

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

  As for resin (X), it is natural that the amount of residual monomer is preferably 0 to 10% by mass, more preferably from the viewpoint of reducing elution from the top coat to the immersion liquid, as a matter of course, the impurities such as metals are small. Is more preferably 0 to 5% by mass and 0 to 1% by mass. Further, the molecular weight distribution (hereinafter also referred to as “Mw / Mn” or “dispersion degree”) is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 to 1.5.

  As the resin (X), 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 and diisopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate; amide solvents such as dimethylformamide and dimethylacetamide; propylene And a solvent that dissolves the resist composition of the present invention, such as glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone.

  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. For purification, for example, a liquid-liquid extraction method that removes residual monomer and oligomer components by combining water and an appropriate solvent; purification in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less Method; Reprecipitation method in which residual monomer is removed by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent; in a solid state such as washing the filtered resin slurry with the poor solvent A conventional method such as a purification method of 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 this 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) Chains such as Ter; cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), alcohols ( (Methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), water, a mixed solvent containing these solvents, etc. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable. In such a solvent containing at least hydrocarbon, the ratio of alcohol (especially methanol) and other solvent (for example, ester such as ethyl acetate, ether 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).

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

Resin (X) may be used by 1 type and may be used together.
50-99.9 mass% is preferable in the total solid, and, as for the compounding quantity of resin (X) in the whole topcoat composition, 60-99.0 mass% is more preferable.

  Although the preferable example of resin (X) is shown below, this invention is not limited to this.

<Additive (A)>
The top coat composition is further referred to as at least one selected from the group consisting of the following (A1), (A2) and (A3) (hereinafter referred to as “additive (A)” or “compound (A)”). ) Is preferably contained.
(A1) Basic compound or base generator (A2) A compound containing at least one bond or group selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond and an ester bond (A3 ) Onium salt

  When the top coat composition contains the additive (A), the effect of the present invention is more excellent. The reason for this is that when (A2) is contained, acid diffusion in the resist film is promoted, and when (A1) or (A3) is contained, excessive diffusion of acid in the resist film is suppressed. However, even if this mechanism is different, it is within the scope of the present invention.

  Among the above (A1) to (A3), the reason that the effect of the present invention is further excellent or (A2) is more preferable.

  The content of the above (A1) to (A3) is as described later, but from the reason that the effect of the present invention is more excellent, 1 to 25% by mass is based on the total solid content of the topcoat composition. Preferably, 2.5-20 mass% is more preferable.

<(A1) Basic compound and base generator>
The topcoat composition preferably contains a basic compound or a base generator (hereinafter, these may be collectively referred to as “compound (A1)” or “additive (A1)”). The effect of the present invention is more excellent because these additives act as a quencher that traps the acid generated from the photoacid generator.

(Basic compound)
The basic compound that can be contained in the topcoat composition is preferably an organic basic compound, and more preferably a nitrogen-containing basic compound. For example, those described as basic compounds that may be contained in the resist composition of the present invention can be used, and specifically, compounds having the structures represented by the above formulas (A) to (E) are preferably used. Can be mentioned.
For example, the compounds classified into the following (1) to (5) and (7) can be used.

  (1) Compound represented by general formula (BS-1)

In general formula (BS-1),
Each R independently represents a hydrogen atom or an organic group. However, at least one of the three Rs is an organic group. This organic group is a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an aryl group, or an aralkyl group.

Although carbon number of the alkyl group as R is not specifically limited, Usually, it is 1-20, Preferably it is 1-12.
Although carbon number of the cycloalkyl group as R is not specifically limited, Usually, it is 3-20, Preferably it is 5-15.

Although carbon number of the aryl group as R is not specifically limited, Usually, it is 6-20, Preferably it is 6-10. Specific examples include a phenyl group and a naphthyl group.
Although carbon number of the aralkyl group as R is not specifically limited, Usually, it is 7-20, Preferably it is 7-11. Specific examples include a benzyl group.

  In the alkyl group, cycloalkyl group, aryl group and aralkyl group as R, a hydrogen atom may be substituted with a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a hydroxy group, a carboxy group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, and an alkyloxycarbonyl group.

  In the compound represented by the general formula (BS-1), it is preferable that at least two of R are organic groups.

  Specific examples of the compound represented by the general formula (BS-1) include tri-n-butylamine, tri-isopropylamine, tri-n-pentylamine, tri-n-octylamine, tri-n-decylamine, Isodecylamine, dicyclohexylmethylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, didecylamine, methyloctadecylamine, dimethylundecylamine, N, N-dimethyldodecylamine, methyldioctadecylamine, N, N -Dibutylaniline, N, N-dihexylaniline, 2,6-diisopropylaniline, and 2,4,6-tri (t-butyl) aniline.

  Moreover, as a preferable basic compound represented by the general formula (BS-1), a compound in which at least one R is an alkyl group substituted with a hydroxy group can be given. Specific examples include triethanolamine and N, N-dihydroxyethylaniline.

In addition, the alkyl group as R may have an oxygen atom in the alkyl chain. That is, an oxyalkylene chain may be formed. As the oxyalkylene chain, —CH ₂ CH ₂ O— is preferable. Specifically, for example, tris (methoxyethoxyethyl) amine and compounds exemplified in the 60th and subsequent lines of column 3 of US6040112 can be mentioned.

  As a basic compound represented by general formula (BS-1), the following are mentioned, for example.

(2) Compound having nitrogen-containing heterocyclic structure This nitrogen-containing heterocyclic ring may have aromaticity or may not have aromaticity. Moreover, you may have two or more nitrogen atoms. Furthermore, you may contain hetero atoms other than nitrogen. Specifically, for example, compounds having an imidazole structure (2-phenylbenzimidazole, 2,4,5-triphenylimidazole, etc.), compounds having a piperidine structure [N-hydroxyethylpiperidine and bis (1,2,2) , 6,6-pentamethyl-4-piperidyl) sebacate], compounds having a pyridine structure (such as 4-dimethylaminopyridine), and compounds having an antipyrine structure (such as antipyrine and hydroxyantipyrine).

  A compound having two or more ring structures is also preferably used. Specific examples include 1,5-diazabicyclo [4.3.0] non-5-ene and 1,8-diazabicyclo [5.4.0] -undec-7-ene.

(3) Amine compound having a phenoxy group An amine compound having a phenoxy group is a compound having a phenoxy group at the terminal opposite to the N atom of the alkyl group contained in the amine compound. The phenoxy group is, for example, a substituent such as an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxy group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. You may have.

This compound more preferably has at least one oxyalkylene chain between the phenoxy group and the nitrogen atom. The number of oxyalkylene chains in one molecule is preferably 3-9, more preferably 4-6. Among the oxyalkylene chains, —CH ₂ CH ₂ O— is particularly preferable.

  Specific examples include 2- [2- {2- (2,2-dimethoxy-phenoxyethoxy) ethyl} -bis- (2-methoxyethyl)]-amine and paragraph <0066 of US2007 / 0224539A1. > The compounds (C1-1) to (C3-3) exemplified in

  The amine compound having a phenoxy group is prepared by reacting, for example, a primary or secondary amine having a phenoxy group with a haloalkyl ether, and adding an aqueous solution of a strong base such as sodium hydroxide, potassium hydroxide or tetraalkylammonium. And then extracted with an organic solvent such as ethyl acetate and chloroform. In addition, the amine compound having a phenoxy group reacts by heating a primary or secondary amine and a haloalkyl ether having a phenoxy group at the terminal, and a strong base such as sodium hydroxide, potassium hydroxide or tetraalkylammonium. It can also be obtained by adding an aqueous solution and then extracting with an organic solvent such as ethyl acetate and chloroform.

(4) Ammonium salt As the basic compound, an ammonium salt can also be used as appropriate. Examples of the anion of the ammonium salt include halides, sulfonates, borates, and phosphates. Of these, halides and sulfonates are particularly preferred.

As the halide, chloride, bromide and iodide are particularly preferable.
As the sulfonate, an organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include alkyl sulfonates having 1 to 20 carbon atoms and aryl sulfonates.

  The alkyl group contained in the alkyl sulfonate may have a substituent. Examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an alkoxy group, an acyl group, and an aryl group. Specific examples of the alkyl sulfonate include methane sulfonate, ethane sulfonate, butane sulfonate, hexane sulfonate, octane sulfonate, benzyl sulfonate, trifluoromethane sulfonate, pentafluoroethane sulfonate, and nonafluorobutane sulfonate.

  Examples of the aryl group contained in the aryl sulfonate include a phenyl group, a naphthyl group, and an anthryl group. These aryl groups may have a substituent. As this substituent, a C1-C6 linear or branched alkyl group and a C3-C6 cycloalkyl group are preferable, for example. Specifically, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl and cyclohexyl groups are preferable. Examples of other substituents include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, cyano, nitro, an acyl group, and an acyloxy group.

  The ammonium salt may be hydroxide or carboxylate. In this case, the ammonium salt is a tetraalkylammonium hydroxide having 1 to 8 carbon atoms (tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra- (n-butyl) ammonium hydroxide, etc.). It is particularly preferred.

  Preferred basic compounds include, for example, guanidine, aminopyridine, aminoalkylpyridine, aminopyrrolidine, indazole, imidazole, pyrazole, pyrazine, pyrimidine, purine, imidazoline, pyrazoline, piperazine, aminomorpholine and aminoalkylmorpholine. . These may further have a substituent.

  Preferred substituents include, for example, amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group And a cyano group.

  Particularly preferable basic compounds include, for example, guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2 -Phenylimidazole, 4,5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2- Diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethyl Pyridine, 4-aminoethylpyridine, 3-amino Pyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6 tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5 methylpyrazine, Examples include pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine and N- (2-aminoethyl) morpholine.

(5) A compound having a proton acceptor functional group and generating a compound which is decomposed by irradiation with actinic rays or radiation to decrease or disappear the proton acceptor property or change from proton acceptor property to acidity ( PA)
The composition according to the present invention has a proton acceptor functional group as a basic compound, and is decomposed by irradiation with actinic rays or radiation, resulting in a decrease, disappearance, or a proton acceptor property. It may further contain a compound that generates a compound that has been changed to acidity (hereinafter also referred to as compound (PA)).

  The proton acceptor functional group is a group that can interact electrostatically with a proton or a functional group having an electron. For example, a functional group having a macrocyclic structure such as a cyclic polyether or a π-conjugated group. It means a functional group having a nitrogen atom with an unshared electron pair that does not contribute. The nitrogen atom having an unshared electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure represented by the following general formula.

  Examples of a preferable partial structure of the proton acceptor functional group include a crown ether, an azacrown ether, a primary to tertiary amine, a pyridine, an imidazole, and a pyrazine structure.

  The compound (PA) is decomposed by irradiation with an actinic ray or radiation to generate a compound in which the proton acceptor property is lowered, disappeared, or changed from proton acceptor property to acidity. Here, the decrease or disappearance of the proton acceptor property or the change from the proton acceptor property to the acid is a change in the proton acceptor property caused by the addition of a proton to the proton acceptor functional group. Specifically, when a proton adduct is formed from a compound having a proton acceptor functional group (PA) and a proton, the equilibrium constant in the chemical equilibrium is reduced.

  Proton acceptor property can be confirmed by measuring pH. In the present invention, the acid dissociation constant pKa of the compound generated by decomposition of the compound (PA) upon irradiation with actinic rays or radiation preferably satisfies pKa <−1, more preferably −13 <pKa <−1. And more preferably −13 <pKa <−3.

  In the present invention, the acid dissociation constant pKa represents the acid dissociation constant pKa in an aqueous solution. For example, Chemical Handbook (II) (4th revised edition, 1993, edited by the Chemical Society of Japan, Maruzen Co., Ltd.) It shows that acid strength is so large that this value is low. Specifically, the acid dissociation constant pKa in an aqueous solution can be measured by measuring an acid dissociation constant at 25 ° C. using an infinitely diluted aqueous solution, and using the following software package 1, Hammett The values based on the substituent constants and the database of known literature values can also be obtained by calculation. The values of pKa described in this specification all indicate values obtained by calculation using this software package.

  Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs)

  The compound (PA) generates, for example, a compound represented by the following general formula (PA-1) as the proton adduct generated by decomposition upon irradiation with actinic rays or radiation. The compound represented by the general formula (PA-1) has an acidic group as well as a proton acceptor functional group, so that the proton acceptor property is reduced or disappeared compared to the compound (PA), or from the proton acceptor property. It is a compound that has changed to acidic.

In general formula (PA-1),
Q _represents -SO 3 H, _-CO 2 H, or _-X 1 _NHX 2 Rf. Here, Rf represents an alkyl group, a cycloalkyl group or an aryl group, and X ₁ and X ₂ each independently represent —SO ₂ — or —CO—.
A represents a single bond or a divalent linking group.
X represents —SO ₂ — or —CO—.
n represents 0 or 1.
B represents a single bond, an oxygen atom, or -N (Rx) Ry-. Rx represents a hydrogen atom or a monovalent organic group, and Ry represents a single bond or a divalent organic group. It may combine with Ry to form a ring, or may combine with R to form a ring.
R represents a monovalent organic group having a proton acceptor functional group.

  Specific examples of the compound (PA) include, but are not limited to, the compounds described in paragraphs <0743> to <0750> of JP2013-83966A.

  Moreover, in this invention, compounds (PA) other than the compound which generate | occur | produces the compound represented by general formula (PA-1) can also be selected suitably. For example, an ionic compound that has a proton acceptor moiety in the cation moiety may be used. More specifically, a compound represented by the following general formula (7) is exemplified.

In the formula, A represents a sulfur atom or an iodine atom.
m represents 1 or 2, and n represents 1 or 2. However, when A is a sulfur atom, m + n = 3, and when A is an iodine atom, m + n = 2.
R represents an aryl group.
R _N represents an aryl group substituted with a proton acceptor functional group.
X ⁻ represents a counter anion.

Specific examples of X ⁻ include the same as Z ⁻ in the general formula (ZI) described above.
Specific examples of the aryl group of R and R _N is a phenyl group are preferably exemplified.

Specific examples of the proton acceptor functional group R _N are the same as those of the proton acceptor functional group described in the foregoing formula (PA-1).

  In the composition of the present invention, the compounding ratio of the compound (PA) in the whole composition is preferably 0.1 to 10% by mass, more preferably 1 to 8% by mass in the total solid content.

(7) Low molecular weight compound having a nitrogen atom and having a group capable of leaving by the action of an acid The composition of the present invention comprises a low molecular weight compound having a nitrogen atom and having a group capable of leaving by the action of an acid (hereinafter referred to as “low molecular weight compound”). In this case, it is also possible to contain “low molecular compound (D)” or “compound (D)”. The low molecular compound (D) preferably has basicity after the group capable of leaving by the action of an acid is eliminated.

  The group capable of leaving by the action of an acid is not particularly limited, but is preferably an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a hemiaminal ether group, and a carbamate group or a hemiaminal ether group. It is particularly preferred.

  The molecular weight of the low molecular weight compound (D) having a group capable of leaving by the action of an acid is preferably 100 to 1000, more preferably 100 to 700, and particularly preferably 100 to 500.

  As the compound (D), an amine derivative having a group capable of leaving by the action of an acid on the nitrogen atom is preferable.

  Compound (D) may have a carbamate group having a protecting group on the nitrogen atom. The protecting group constituting the carbamate group can be represented by the following general formula (d-1).

In general formula (d-1),
R ′ each independently represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxyalkyl group. R ′ may be bonded to each other to form a ring.

  R ′ is preferably a linear or branched alkyl group, cycloalkyl group, or aryl group. More preferably, it is a linear or branched alkyl group or cycloalkyl group.

  The compound (D) particularly preferably has a structure represented by the following general formula (A).

  The compound (D) may correspond to the above basic compound as long as it is a low molecular compound having a group capable of leaving by the action of an acid.

In General Formula (A), R _a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. When n = 2, two R _{a s} may be the same or different, and the two R _a are bonded to each other to form a divalent heterocyclic hydrocarbon group (preferably having a carbon number of 20 or less) or A derivative thereof may be formed.

R _b independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxyalkyl group. However, in -C ( _Rb ) ( _Rb ) ( _Rb ), when one or more _Rb is a hydrogen atom, at least one of the remaining _Rb is a cyclopropyl group, a 1-alkoxyalkyl group or an aryl. It is a group.

At least two R _b may combine to form an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic hydrocarbon group or a derivative thereof.

  n represents an integer of 0 to 2, m represents an integer of 1 to 3, and n + m = 3.

  Specific examples of the particularly preferable compound (D) in the present invention include compounds described in paragraphs <0786> to <0788> of JP2013-83966A, but the present invention is not limited thereto. .

The compound represented by the general formula (A) can be synthesized based on JP2007-298869A, JP2009-199021A, and the like.
In the present invention, the low molecular compound (D) can be used singly or in combination of two or more.

Other usable compounds include compounds synthesized in Examples of JP-A No. 2002-363146, compounds described in paragraph 0108 of JP-A No. 2007-298869, and the like.
A photosensitive basic compound may be used as the basic compound. As the photosensitive basic compound, for example, JP-T-2003-524799 and J. Org. Photopolym. Sci & Tech. Vol. 8, P.I. 543-553 (1995) etc. can be used.
As the basic compound, a so-called photodegradable base may be used. Examples of the photodegradable base include onium salts of carboxylic acids and onium salts of sulfonic acids that are not fluorinated at the α-position. Specific examples of the photodegradable base can include paragraph 0145, Japanese Patent Application Laid-Open No. 2008-158339, and Japanese Patent 399146 of WO2014 / 133308A1.

(Basic compound content)
The content of the basic compound in the top coat composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and still more preferably 1% by mass or more, based on the solid content of the top coat composition. 2.5 mass% or more is particularly preferable.
On the other hand, the upper limit of the content of the basic compound is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, based on the solid content of the topcoat composition, and 5% by mass or less. Is particularly preferred.

(Base generator)
Examples of the base generator (photobase generator) that can be contained in the topcoat composition include, for example, JP-A-4-151156, JP-A-4-162040, JP-A-5-197148, JP-A-5-5995, and JP-A-6-194434. No. 8-146608, No. 10-83079, and European Patent No. 622682.
Moreover, the compounds described in JP 2010-243773 A are also used as appropriate.
Specific examples of the photobase generator include 2-nitrobenzyl carbamate, 2,5-dinitrobenzyl cyclohexyl carbamate, N-cyclohexyl-4-methylphenylsulfonamide and 1,1-dimethyl-2-phenylethyl. -N-isopropyl carbamate is preferably exemplified, but not limited thereto.

(Base generator content)
The content of the base generator in the top coat composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 1% by mass or more, based on the solid content of the top coat composition. 2.5 mass% or more is particularly preferable.
On the other hand, the upper limit of the content of the base generator is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, based on the solid content of the top coat composition, and 5% by mass or less. Is particularly preferred.

<(A2) Compound containing a bond or group selected from the group consisting of ether bond, thioether bond, hydroxyl group, thiol group, carbonyl bond and ester bond>
A compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond and an ester bond (hereinafter referred to as “compound (A2)” or “additive (A2)”) Will be described below.

  As described above, the compound (A2) is a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond and an ester bond.

  As described above, the compound (A2) includes at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond. In one embodiment of the present invention, the compound (A2) preferably has two or more groups or bonds selected from the above group, more preferably three or more, and still more preferably four or more. In this case, the groups or bonds selected from the ether bond, thioether bond, hydroxyl group, thiol group, carbonyl bond and ester bond contained in the compound (A2) may be the same or different from each other. Good.

  In one embodiment of the present invention, the compound (A2) preferably has a molecular weight of 3000 or less, more preferably 2500 or less, still more preferably 2000 or less, and particularly preferably 1500 or less.

In one embodiment of the present invention, the number of carbon atoms contained in the compound (A2) is preferably 8 or more, more preferably 9 or more, and still more preferably 10 or more.
In one embodiment of the present invention, the number of carbon atoms contained in the compound (A2) is preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less.

  In one embodiment of the present invention, the compound (A2) is preferably a compound having a boiling point of 200 ° C. or higher, more preferably a compound having a boiling point of 220 ° C. or higher, and a compound having a boiling point of 240 ° C. or higher. More preferably it is.

In one embodiment of the present invention, the compound (A2) is preferably a compound having an ether bond, preferably two or more ether bonds, more preferably three or more, and four or more. More preferably.
In one embodiment of the present invention, the compound (A2) further preferably contains a repeating unit containing an oxyalkylene structure represented by the following general formula (1).

Where
R ₁₁ represents an alkylene group which may have a substituent,
n represents an integer of 2 or more,
* Represents a bond.

The number of carbon atoms of the alkylene group represented by R ₁₁ in the general formula (1) is not particularly limited, but is preferably 1 to 15, more preferably 1 to 5, and 2 or 3. More preferably, 2 is particularly preferable. When this alkylene group has a substituent, the substituent is not particularly limited, but is preferably an alkyl group (preferably having 1 to 10 carbon atoms), for example.
n is preferably an integer of 2 to 20, and among them, it is more preferably 10 or less because DOF becomes larger.
The average value of n is preferably 20 or less, more preferably 2 to 10, more preferably 2 to 8, and particularly preferably 4 to 6 because the DOF becomes larger. preferable. Here, the “average value of n” means the value of n determined so that the weight average molecular weight of the compound (A2) is measured by GPC and the obtained weight average molecular weight matches the general formula. If n is not an integer, round it off.
A plurality of R ₁₁ may be the same or different.

  Moreover, it is preferable that the compound which has the partial structure represented by the said General formula (1) is a compound represented by the following general formula (1-1) from the reason for DOF becoming larger.

Where
Definition of R _11, specific examples and preferred embodiments are the same as R ₁₁ in general formula (1).
R ₁₂ and R ₁₃ each independently represents a hydrogen atom or an alkyl group. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 1-15. R ₁₂ and R ₁₃ may combine with each other to form a ring.
m represents an integer of 1 or more. m is preferably an integer of 1 to 20, and among them, it is more preferably 10 or less for the reason that DOF becomes larger.
The average value of m is preferably 20 or less, more preferably 1 to 10, more preferably 1 to 8, and particularly preferably 4 to 6 because the DOF becomes larger. preferable. Here, the “average value of m” is synonymous with the “average value of n” described above.
When m is 2 or more, a plurality of R ₁₁ may be the same or different.

  In one embodiment of the present invention, the compound having a partial structure represented by the general formula (1) is preferably an alkylene glycol containing at least two ether bonds.

  Compound (A2) may be a commercially available product, or may be synthesized by a known method.

  Although the specific example of a compound (A2) is given to the following, this invention is not limited to these.

(Content of Compound (A2))
The content of the compound (A2) in the topcoat composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, based on the solid content of the topcoat composition. 2.5 mass% or more is especially preferable, and 3 mass% or more is most preferable.
On the other hand, the upper limit of the content of the compound (A2) is preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less, and 18% by mass based on the solid content of the topcoat composition. The following are particularly preferred:

<(A3) Onium salt>
The topcoat composition can contain an onium salt that is a weak acid relative to the acid generator. When an acid generated from an acid generator upon irradiation with actinic rays or radiation collides with an onium salt having an unreacted weak acid anion, an onium salt having a strong acid anion is generated by releasing a weak acid by salt exchange. In this process, the strong acid is exchanged with a weak acid having a lower catalytic ability, so that the acid is apparently deactivated and the acid diffusion can be controlled.

  The onium salt that is a weak acid relative to the acid generator is preferably a compound represented by the following general formulas (d1-1) to (d1-3).

In the formula, R ⁵¹ represents a hydrocarbon group which may have a substituent, and Z ^2c represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (however, a carbon adjacent to S). R ⁵² is an organic group, Y ³ is a linear, branched or cyclic alkylene group or an arylene group, and Rf is a fluorine atom. Each of the M ⁺ is independently a sulfonium or iodonium cation.

Preferable examples of the sulfonium cation or iodonium cation represented by M ⁺ include a sulfonium cation exemplified by the general formula (ZI) and an iodonium cation exemplified by the general formula (ZII).

Preferable examples of the anion moiety of the compound represented by the general formula (d1-1) include the structures exemplified in paragraph [0198] of JP2012-242799A.
Preferable examples of the anion moiety of the compound represented by the general formula (d1-2) include the structures exemplified in paragraph [0201] of JP2012-242799A.
Preferable examples of the anion moiety of the compound represented by the general formula (d1-3) include the structures exemplified in paragraphs [0209] and [0210] of JP2012-242799A.

The onium salt that is a weak acid relative to the acid generator is a compound (C) having a cation moiety and an anion moiety in the same molecule, and the cation moiety and the anion moiety being linked by a covalent bond ( (Hereinafter also referred to as “compound (CA)”).
The compound (CA) is preferably a compound represented by any one of the following general formulas (C-1) to (C-3).

In general formulas (C-1) to (C-3),
R ₁ , R ₂ and R ₃ represent a substituent having 1 or more carbon atoms.
L ₁ represents a divalent linking group or a single bond linking the cation moiety and the anion moiety.
-X ^{- is,} -COO _^-, -SO 3 _- represents an anion portion selected from ^{_{-R 4 -, -SO 2 -,}} -N. R ₄ has 1 having a carbonyl group: —C (═O) —, a sulfonyl group: —S (═O) ₂ —, and a sulfinyl group: —S (═O) — at the site of connection with the adjacent N atom. Represents a valent substituent.
R ₁ , R ₂ , R ₃ , R ₄ and L ₁ may be bonded to each other to form a ring structure. In (C-3), two of R _{1 to} R ₃ may be combined to form a double bond with the N atom.

Examples of the substituent having 1 or more carbon atoms in R _{1 to} R ₃ include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, and a cycloalkylamino. A carbonyl group, an arylaminocarbonyl group, etc. are mentioned. Preferably, they are an alkyl group, a cycloalkyl group, and an aryl group.

L ₁ as the divalent linking group is a linear or branched alkylene group, cycloalkylene group, arylene group, carbonyl group, ether bond, ester bond, amide bond, urethane bond, urea bond, and two types thereof. Examples include groups formed by combining the above. L ₁ is more preferably an alkylene group, an arylene group, an ether bond, an ester bond, or a group formed by combining two or more of these.
Preferable examples of the compound represented by the general formula (C-1) include paragraphs [0037] to [0039] of JP2013-6827A and paragraphs [0027] to [0029] of JP2013-8020A. ] Can be mentioned.
Preferable examples of the compound represented by the general formula (C-2) include the compounds exemplified in paragraphs [0012] to [0013] of JP2012-189977A.
Preferable examples of the compound represented by the general formula (C-3) include the compounds exemplified in paragraphs [0029] to [0031] of JP 2012-252124 A.

(Onium salt content)
The content of the onium salt in the top coat composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and further preferably 2.5% by mass or more based on the solid content of the top coat composition.
On the other hand, the upper limit of the content of the onium salt is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, and more preferably 8% by mass or less, based on the solid content of the topcoat composition. Particularly preferred.

<Surfactant>
The topcoat composition of the present invention may further contain a surfactant.

<Method for preparing topcoat composition>
In the top coat composition of the present invention, it is preferable to dissolve the above-described components in a solvent and filter the solution. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon having a pore size of 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less. Note that a plurality of types of filters may be connected in series or in parallel. Moreover, the composition may be filtered a plurality of times, and the step of filtering a plurality of times may be a circulation filtration step. Furthermore, you may perform a deaeration process etc. with respect to a composition before and after filter filtration.

[Resist pattern]
The present invention also relates to a resist pattern formed by the above-described pattern forming method of the present invention.

[Electronic Device Manufacturing Method and Electronic Device]
The present invention also relates to an electronic device manufacturing method including the pattern forming method of the present invention described above, and an electronic device manufactured by the manufacturing method.
The electronic device of the present invention is suitably mounted on electrical and electronic equipment (home appliances, OA / media related equipment, optical equipment, communication equipment, and the like).

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

<Synthesis Example 1: Synthesis of Resin (1)>
102.3 parts by mass of cyclohexanone was heated to 80 ° C. under a nitrogen stream. While stirring this liquid, there were 22.2 parts by mass of a monomer represented by the following structural formula LM-2, 22.8 parts by mass of a monomer represented by the following structural formula PM-1, and the following structural formula PM-9. A mixed solution of 6.6 parts by mass of a monomer, 189.9 parts by mass of cyclohexanone, dimethyl 2,2′-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.], 5 hours It was dripped over. The solution after completion of the dropwise addition was further stirred at 80 ° C. for 2 hours. The resulting reaction solution was allowed to cool, then re-precipitated with a large amount of hexane / ethyl acetate (mass ratio 9: 1), filtered, and the obtained solid was vacuum-dried to obtain 41.1 mass of resin (1). I got a part.

The weight average molecular weight (Mw: converted to polystyrene) obtained from GPC (carrier: tetrahydrofuran (THF)) of the obtained resin (1) was Mw = 9500, and the dispersity was Mw / Mn = 1.62. ^The composition ratio measured by ¹³ C-NMR was 40/50/10 in molar ratio.

<Synthesis Example 2: Synthesis of Resins (2) to (12)>
The same operations as in Synthesis Example 1 were performed to synthesize the following resins (2) to (12) as acid-decomposable resins.
Hereinafter, the composition ratio (molar ratio; corresponding in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit in the resins (1) to (12) are shown in Table 1. These were calculated | required by the method similar to resin (1) mentioned above.

  The repeating units in Table 1 are as follows.

<Preparation of resist composition>
The components shown in Table 2 below are dissolved in the solvent shown in Table 2 below to prepare a solution having a solid content concentration of 3.5% by mass, and this is filtered through a polyethylene filter having a pore size of 0.04 μm. Re-1 to Re-17 were prepared.

  Abbreviations in Table 2 are as follows.

<Acid generator>

<Basic compound>

<Hydrophobic resin>

  B-1: Resin (Mw = 5300, Mw / Mn = 1.35) having the following repeating units at a composition ratio of 39/57/2/2 (molar ratio; corresponding in order from the left)

<Solvent>
SL-1: Propylene glycol monomethyl ether acetate (PGMEA)
SL-2: Cyclohexanone SL-3: Propylene glycol monomethyl ether (PGME)
SL-4: γ-butyrolactone

<Synthesis Example 3: Synthesis of Resins (X1) to (X14)>
The same operations as in Synthesis Example 1 were performed to synthesize the following resins (X1) to (X14) included in the topcoat composition. Table 3 shows the composition ratio (molar ratio; corresponding in order from the left), weight average molecular weight (Mw), dispersity (Mw / Mn), and glass transition temperature (Tg) of each repeating unit in each synthesized resin. . A method for measuring the glass transition temperature (Tg) will be described later.

(Measurement method of glass transition temperature (Tg))
The glass transition temperature (Tg) of the resins (X1) to (X14) was determined by weighing about 2 mg of a vacuum-dried resin sample on an aluminum pan using a differential scanning calorimeter (DSC) Q2000 manufactured by TA Instruments. The aluminum pan was set in a DSC measurement holder, and the temperature was raised from 10 to 300 ° C. at 2 ° C./min, and the inflection point in the temperature rise of the resin was obtained.

<Preparation of topcoat composition>
The components shown in Table 4 below are dissolved in the solvent shown in Table 4 below to prepare a solution having a solid content concentration of 3.0% by mass, which is filtered through a polyethylene filter having a pore size of 0.04 μm, and a top coat composition. Products A-1 to A-16 were prepared.

  Abbreviations in Table 4 are as follows.

<Additives>

<Examples 1-22 and Comparative Examples 1-3>
A resist pattern was formed using the prepared resist composition and topcoat composition, and evaluation was performed by the following method.

(Hole pattern formation)
A composition ARC29SR (made by Brewer) for forming an organic antireflection film was applied onto a silicon wafer, and baked at 205 ° C. for 60 seconds to form an organic antireflection film having a film thickness of 86 nm. The resist composition shown was applied and baked at 100 ° C. for 60 seconds to form a resist film having a thickness of 90 nm.
Next, the top coat composition shown in the following Table 5 is applied onto the resist film, and then baked at the PB temperature (unit: ° C.) shown in the following Table 5 for 60 seconds to form an upper film having a thickness of 90 nm. (Topcoat) was formed.
Next, using an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA 1.20, C-Quad, outer sigma 0.730, inner sigma 0.630, XY deflection), the hole part is 65 nm and between the holes The resist film on which the upper layer film was formed was subjected to pattern exposure through a square array halftone mask (hole portion was shielded) having a pitch of 100 nm. Ultra pure water was used as the immersion liquid. Then, it heated at 105 degreeC for 60 second (PEB: Post Exposure Bake). Next, development was carried out by padding with an organic developer described in Table 5 for 30 seconds, and padding was carried out for 30 seconds with a rinse solution described in Table 5 below. Subsequently, the wafer was rotated at 2000 rpm for 30 seconds to obtain a hole pattern with a hole diameter of 50 nm.

(Formation of line and space pattern)
In the same manner as the formation of the hole pattern, a film was formed by coating each composition on the silicon wafer in the order of the organic antireflection film, the resist film, and the upper layer film.
Next, using an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA1.20, Dipole, outer sigma 0.800, inner sigma 0.564, Y deflection), the space portion is 55 nm and the pitch between the spaces Pattern exposure was performed through a halftone mask having a thickness of 110 nm. Ultra pure water was used as the immersion liquid. Then, it heated at 90 degreeC for 60 second (PEB: Post Exposure Bake). Next, development was carried out by padding with an organic developer described in Table 5 for 30 seconds, and padding was carried out for 30 seconds with a rinse solution described in Table 5 below. Subsequently, the wafer was rotated at a rotational speed of 2000 rpm for 30 seconds to obtain a line pattern having a line width of 50 nm.

(CD uniformity (CDU))
A hole pattern with a hole diameter of 50 nm formed under the above exposure and development conditions (formation of hole pattern) was observed using a line width measurement scanning electron microscope SEM (Hitachi, Ltd. S-9380). The hole diameters of 100 arbitrary hole patterns were measured, and a value (3σ) that was three times the standard deviation (σ) of the average value was calculated. A smaller value indicates better performance. The results are shown in Table 5 below.

(Line edge roughness (LER))
A line pattern with a line width of 50 nm formed under the exposure and development conditions described above (formation of line and space pattern) was observed using a line width measurement scanning electron microscope SEM (Hitachi, Ltd. S-9380). . The distance between the reference line that should have an edge and the actual edge was measured at 50 equally spaced points included in the range of 5 μm in the longitudinal direction of the line pattern. The standard deviation of this distance was calculated, 3σ (unit: nm) was calculated, and this was taken as LER. A smaller value indicates better performance. The results are shown in Table 5 below.

(Exposure latitude (EL))
The exposure amount (unit: mJ / cm ² ) when resolving a line pattern with a line width of 50 nm is set as the optimum exposure amount, and then the exposure that allows the line width to be 50 nm ± 10% when the exposure amount is changed. The amount width was obtained, and the obtained exposure amount width was divided by the optimum exposure amount and displayed as a percentage, and the exposure latitude (EL, unit:%) was obtained. The larger the value of EL, the better the performance change due to the change in exposure amount. The results are shown in Table 5 below.

  As is apparent from the results shown in Table 5 above, for Examples 1 to 22, CDU and LER are superior to Comparative Examples 1 to 3, and EL is equal to or higher than Comparative Examples 1 to 3 and good. there were.

When Example 11 and Example 15 are compared, the content of the acid generator is higher than that of Example 15 using the resist composition Re-1 in which the content of the acid generator is 17.0% by mass. In Example 11 using the resist composition Re-11 having 24.0% by mass, the CDU and LER values were smaller and more excellent.
Moreover, when Example 15 and Example 16 are contrasted, the topcoat composition A-12 containing an additive was used rather than Example 15 using the topcoat composition A-11 which does not contain an additive. In Example 16, the CDU and LER values were small and excellent, and the EL value was large and superior.
Further, when Example 13 and Example 16 are compared, Example 13 having a Tg of 101 ° C. is more EL than that of Example 16 in which the Tg of the resin contained in the topcoat composition is 72 ° C. The value of was larger and better.
Further, when Example 9 and Example 17 are compared, Example 17 in which the PB temperature is 120 ° C. is superior to Example 9 in which the PB temperature is 90 ° C., and the CDU and LER values are small and excellent. Moreover, the value of EL was large and more excellent.

Claims (13)

An actinic ray-sensitive or radiation-sensitive resin composition containing a resin whose polarity is increased by the action of an acid and a compound that generates an acid upon irradiation with actinic rays or radiation is applied onto a substrate to form a resist film. Forming step a;
A step b of forming an upper layer film on the resist film by applying an upper layer film forming composition on the resist film;
A step c in which the resist film on which the upper layer film is formed is subjected to immersion exposure using ArF excimer laser light (193 nm) ;
Developing the exposed resist film using a developer containing an organic solvent to form a pattern; and
Wherein the composition for forming an upper layer film comprises (A2) at least two bonds or groups selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond and an ester bond. The content of the compound containing a compound having a molecular weight of 3000 or less and generating an acid upon irradiation with the actinic ray or radiation in the actinic ray-sensitive or radiation-sensitive resin composition is the actinic ray-sensitive or radiation-sensitive property. The pattern formation method which is 16.5 mass% or more on the basis of the total solid of a resin composition. An actinic ray-sensitive or radiation-sensitive resin composition containing a resin whose polarity is increased by the action of an acid and a compound that generates an acid upon irradiation with actinic rays or radiation is applied onto a substrate to form a resist film. Forming step a;
A step b of forming an upper film on the resist film by applying an upper film forming composition on the resist film;
A step c in which the resist film on which the upper layer film is formed is subjected to immersion exposure using ArF excimer laser light (193 nm) ;
Developing the exposed resist film using a developer containing an organic solvent to form a pattern; and
The upper layer film-forming composition comprises (A2) a molecular weight containing at least one bond or group selected from the group consisting of (A2) an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond and an ester bond The compound (A2) contains not more than 3000 compounds, and the compound (A2) has 9 or more carbon atoms, and generates an acid upon irradiation with the actinic ray or radiation in the actinic ray-sensitive or radiation-sensitive resin composition. The pattern forming method, wherein the content of the compound to be used is 16.5% by mass or more based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition. The pattern formation method of Claim 1 or 2 whose immersion liquid in the said process c is water. The pattern formation method of any one of Claims 1-3 in which the said composition for upper layer film formation further contains at least 1 sort (s) selected from the group which consists of following (A1) and (A3).
(A1) Basic compound or base generator (A3) Onium salt The upper layer film forming composition further contains a resin (X) containing CH ₃ partial structure side chain moiety, a pattern forming method according to any one of claims 1-4. The pattern formation method according to claim 5, wherein the resin (X) does not have an aromatic group. The pattern formation method of Claim 5 or 6 in which the said resin (X) contains the repeating unit represented by the following general formula (II).
In the general formula _{(II), X b1} represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom, _{R 2} has one or more CH ₃ partial structure represents an organic group. In the general formula (II), R ₂ has one or more CH ₃ partial structure, an alkyl group or an alkyl-substituted cycloalkyl group, a pattern forming method according to claim 7. In the general formula (II), _{R 2} is, CH ₃ a partial structure having 10 or less 2 or more, the pattern forming method according to claim 7 or 8. The glass transition temperature of the resin (X) is 50 ° C. or more, the pattern forming method according to any one of claims 5-9. The compounds generating an acid by irradiation of the actinic ray or radiation is a compound which generates an acid upon irradiation with actinic rays or radiation represented by the following general formula (3), any one of claims 1-10 The pattern forming method according to 1.
However, in general formula (3),
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₄ and R ₅ each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and when there are a plurality of R ₄ and R ₅ , R ₄ and R ₅ are the same But it can be different.
L represents a divalent linking group, and when there are a plurality of L, L may be the same or different.
W represents an organic group containing a cyclic structure.
o represents an integer of 1 to 3. p represents an integer of 0 to 10. q represents an integer of 0 to 10.
X ⁺ represents a cation. Wherein step b is, after coating the composition for formation of upper layer film on the resist film, by heating at 100 ° C. or higher, a step of forming an upper layer film on the resist film, according to claim 1 to 11 The pattern formation method of any one of these. Claims including a pattern forming method according to any one of claim 1 to 12, a method for fabricating an electronic device.