WO2020262134A1

WO2020262134A1 - Purification method for actinic ray-sensitive or radiation-sensitive resin composition, pattern-forming method, and production method for electronic device

Info

Publication number: WO2020262134A1
Application number: PCT/JP2020/023711
Authority: WO
Inventors: 直紘丹呉; 慶山本; 惠瑜王
Original assignee: 富士フイルム株式会社
Priority date: 2019-06-28
Filing date: 2020-06-17
Publication date: 2020-12-30
Also published as: TW202104144A; JP7239695B2; JPWO2020262134A1

Abstract

The present invention addresses the problem of providing a purification method for an actinic ray-sensitive or radiation-sensitive resin composition which can be used to form a pattern in which defects are inhibited. The present invention also addresses another problem of providing: a pattern-forming method including a purification step based on the purification method; and a method for producing an electronic device using the pattern-forming method. The purification method according to the present invention is for an actinic ray-sensitive or radiation-sensitive resin composition containing at least a resin having polarity which increases due to action of an acid, a compound which generates an acid due to irradiation with an actinic ray or a radiation, and a solvent, wherein the compound which generates an acid due to irradiation with an actinic ray or a radiation, includes one or more compounds selected from the group consisting of compounds (I)-(III), and the method comprises step X for filtering the actinic ray-sensitive or radiation-sensitive resin composition through two or more filters.

Description

A method for purifying an actinic or radiation-sensitive resin composition, a method for forming a pattern, a method for manufacturing an electronic device.

The present invention relates to a method for purifying an actinic or radiation-sensitive resin composition, a method for forming a pattern, and a method for producing an electronic device.

Since the resist for KrF excimer laser (248 nm), a pattern forming method using chemical amplification has been used to compensate for the decrease in sensitivity due to light absorption. For example, in the positive chemical amplification method, first, the photoacid generator contained in the exposed portion is decomposed by light irradiation to generate an acid. Then, it is contained in the actinic cheilitis or radiation-sensitive resin composition (hereinafter, also referred to as "resist composition") due to the catalytic action of the acid generated in the baking (PEB: Post Exposure Bake) process after exposure. The solubility in the developing solution is changed by changing the alkali-insoluble group of the resin to the alkali-soluble group. Then, for example, development is carried out using a basic aqueous solution. As a result, the exposed portion is removed to obtain a desired pattern.
Due to the miniaturization of semiconductor devices, the wavelength of the exposure light source has been shortened and the numerical aperture (NA) of the projection lens has been increased. Currently, an exposure machine using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed. ing.
Under these circumstances, various configurations have been proposed as sensitive light-sensitive or radiation-sensitive resin compositions.

For example, Patent Document 1 discloses an acid generator containing a salt represented by the following formula (I) as a component used in a resist composition.

JP 2015-024989

When the present inventors examined the resist composition described in Patent Document 1, they found that when a pattern was formed using the resist composition, many defects were generated in the pattern. That is, it was clarified that in the production of the resist composition, further improvement is required to suppress defects in the formed pattern.

Therefore, an object of the present invention is to provide a method for purifying an actinic cheilitis or radiation-sensitive resin composition capable of forming a pattern in which defects are suppressed.
Another object of the present invention is to provide a pattern forming method including a purification step based on the purification method, and a method for manufacturing an electronic device using the pattern forming method.

The present inventors have completed the present invention as a result of diligent studies to solve the above problems. That is, it was found that the above problem can be solved by the following configuration.

[1] A method for purifying an active ray-sensitive or radiation-sensitive resin composition containing at least a resin whose polarity is increased by the action of an acid, a compound that generates an acid by irradiation with active light or radiation, and a solvent. ,
The compound that generates an acid by irradiation with active light or radiation contains one or more compounds selected from the group consisting of compounds (I) to (III) described later.
A method for purifying an actinic or radiation-sensitive resin composition, which comprises step X of passing the actinic or radiation-sensitive resin composition through two or more types of filters and filtering the composition.
[2] The method for purifying an actinic or radiation-sensitive resin composition according to [1], wherein the critical surface tension of the filter is 10 to 90 dyne / cm.
[3] The method for purifying an actinic cheilitis or radiation-sensitive resin composition according to [1] or [2], wherein the critical surface tension of at least one of the filters is 40 to 90 dyne / cm.
[4] The critical surface tension of at least one of the filters is 40 to 90 dyne / cm, and the critical surface tension of at least one of the filters is 10 to 39 dyne / cm. [1] to [ 3] The method for purifying an active light-sensitive or radiation-sensitive resin composition according to any one of.
[5] In the step X, the actinic cheilitis or the actinic cheilitis resin composition is passed through two or more kinds of filters arranged in the flow path and filtered, and then the actinic cheilitis is passed through the filter. Alternatively, the method for purifying an actinic cheilitis or radiation-sensitive resin composition according to any one of [1] to [4], which is a step X2 in which the radiation-sensitive resin composition is further guided to the same filter and filtered again. ..
[6] The actinic cheilitis or sensation according to any one of [1] to [5], which comprises a step Y of immersing the filter used in the step X in an organic solvent before the step X. A method for purifying a radioactive resin composition.
[7] The sensitive light-sensitive or radiation-sensitive resin composition contains an organic solvent and contains
The sensitive light-sensitive or radiation-sensitive resin composition according to [6], wherein the organic solvent for immersing the filter and the organic solvent contained in the sensitive light-sensitive or radiation-sensitive resin composition are of the same type. Purification method.
[8] A step of purifying the sensitive light-sensitive or radiation-sensitive resin composition by the method for purifying the sensitive light-sensitive or radiation-sensitive resin composition according to any one of [1] to [7].
A step of forming a resist film on a support using the purified actinic cheilitis or radiation-sensitive resin composition, and
The process of exposing the resist film and
A pattern forming method comprising a step of developing the exposed resist film with a developing solution.
[9] A method for manufacturing an electronic device, which comprises the pattern forming method according to [8].

According to the present invention, it is possible to provide a method for purifying a sensitive light-sensitive or radiation-sensitive resin composition capable of forming a pattern in which defects are suppressed.
Further, according to the present invention, it is possible to provide a pattern forming method including a purification step based on the purification method, and a method for manufacturing an electronic device using the pattern forming method.

It is the schematic of the apparatus for demonstrating an example of embodiment of process X1. It is the schematic of the apparatus for demonstrating an example of Embodiment of process X2. It is a schematic diagram for demonstrating the evaluation method of defect evaluation after pattern formation, and is an example of observed defects. It is a schematic diagram for demonstrating the evaluation method of defect evaluation after pattern formation, and is another example of observed defects.

Hereinafter, a method for purifying an actinic or radiation-sensitive resin composition, a method for forming a pattern, and a method for producing an electronic device according to the present invention will be described in detail.
The description of the constituent elements described below may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
Regarding the notation of a group (atomic group) in the present specification, unless it is contrary to the gist of the present invention, the notation without substitution and non-substituent includes a group having a substituent as well as a group having no substituent. To do. 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). Further, the "organic group" in the present specification means a group containing at least one carbon atom.
Unless otherwise specified, the substituent is preferably a monovalent substituent.
As used herein, the term "active light" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, extreme ultraviolet rays (EUV light: Extreme Ultraviolet), X rays, and electron beams (EB). : Electron Beam) and the like. As used herein, "light" means active light or radiation.
Unless otherwise specified, the term "exposure" as used herein refers to not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays, X-rays, EUV light, etc., but also electron beams and It also includes drawing with particle beams such as ion beams.
In the present specification, "-" is used to mean that the numerical values described before and after it are included as the lower limit value and the upper limit value.
The bonding direction of the divalent groups described herein is not limited unless otherwise specified. For example, when Y is -COO- in the compound represented by the general formula "XYZ", Y may be -CO-O-, and is -O-CO-. You may. Moreover, the said compound may be "X-CO-O-Z" or "X-O-CO-Z".

In the present specification, (meth) acrylate represents acrylate and methacrylate, and (meth) acrylic represents acrylic and methacrylic.
In the present specification, the weight average molecular weight (Mw), the number average molecular weight (Mn), and the degree of dispersion (also referred to as molecular weight distribution) (Mw / Mn) of the resin are GPC (Gel Permeation Chromatography) apparatus (HLC-8120GPC manufactured by Toso). ) GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Toso Co., Ltd., column temperature: 40 ° C., flow velocity: 1.0 mL / min, detector: differential refractometer It is defined as a polystyrene equivalent value by a detector (Refractive Index Detector).

In the present specification, the acid dissociation constant (pKa) represents the acid dissociation constant (pKa) in an aqueous solution, and specifically, using the following software package 1, a database of Hammett's substituent constants and known literature values. The value based on is the value obtained by calculation. All the values of the acid dissociation constant (pKa) described in the present specification indicate the values calculated by using this software package.

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

On the other hand, the acid dissociation constant (pKa) can also be obtained by the molecular orbital calculation method. As a specific method for this, there is a method of calculating by calculating H ⁺ dissociation free energy in an aqueous solution based on a thermodynamic cycle. The calculation method of H ⁺ dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in the literature and are not limited to this. .. There are a plurality of software that can perform DFT, and examples thereof include Gaussian16.

As described above, the acid dissociation constant (pKa) in the present specification refers to a value obtained by calculating a value based on a database of Hammett's substituent constant and publicly known literature value using Software Package 1. If the acid dissociation constant (pKa) cannot be calculated by this method, the value obtained by Gaussian 16 based on DFT (density general function method) shall be adopted.
Further, the acid dissociation constant (pKa) in the present specification refers to the "acid dissociation constant (pKa) in an aqueous solution" as described above, but when the acid dissociation constant (pKa) in an aqueous solution cannot be calculated, , "Acid dissociation constant (pKa) in dimethyl sulfoxide (DMSO) solution" shall be adopted.

In the present specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[Method for Purifying Actinic Photosensitive or Radiation Sensitive Resin Composition]
The method for purifying an actinic or radiation-sensitive resin composition of the present invention (hereinafter, also referred to as “the purification method of the present invention”) is a resin whose polarity is increased by the action of an acid (hereinafter, “acid-degradable resin” or “acid-degradable resin”). "Resin (A)"), a compound that generates an acid by irradiation with active light or radiation (hereinafter, also referred to as "photoacid generator"), and a solvent. The present invention relates to a method for purifying a radioactive resin composition (hereinafter, also referred to as “resist composition”).
The first feature of the purification method of the present invention is that the photoacid generator is one or more photoacid generators selected from the group consisting of compounds (I) to (III) described later (hereinafter, "specific light"). It is also referred to as an "acid generator"). Further, the second characteristic point of the purification method of the present invention is that it includes a step X of passing the resist composition to be purified through two or more kinds of filters and filtering it.

Nowadays, the present inventors have a photoacid containing a polyvalent (for example, divalent) salt structure in the molecule, such as the photoacid generator represented by the above general formula (I) used in Patent Document 1. The generator tends to form aggregates between the photoacid generators and / or with other compounding components due to the salt structure in the resist composition, and as a result, when a pattern is formed. It was found that many defects occur in the.
As a result of diligent studies on the above findings, the present inventors have found that in a resist composition containing a specific acid generator, which is a photoacid generator containing a polyvalent salt structure in the molecule, the resist composition is used. It was clarified that the amount of defects generated in the obtained pattern can be remarkably reduced by carrying out the step X of passing through two or more types of filters for filtration.
Although the mechanism of action is not clear, according to the above step X, the cohesiveness of the specific photoacid generator contained in the resist composition is relaxed, and as a result, the specific photoacid generators and / or the specific light are alleviated. It is presumed that this is because the formation of aggregates between the acid generator and other compounding components is suppressed.

Further, as will be described later, the critical surface tension of the filter used in the above step X is preferably 10 to 90 din / cm. In particular, when the critical surface tension of at least one of the filters used in the step X is 40 to 90 din / cm (among others, the filter of at least one of the filters used in the step X When the critical surface tension is 40 to 90 dyne / cm and the critical surface tension of at least one filter is 10 to 39 dyne / cm), it has been confirmed that the defect suppression property of the obtained pattern is more excellent.

Further, as described later, it was confirmed that when the purification method of the present invention is the purification method T1 or the purification method T2 (preferably the purification method T3), the defect suppressing property of the obtained pattern is more excellent. ing.

The step X included in the purification method of the present invention will be described below.

[Step X]
The step X is a step of passing the resist composition through two or more types of filters (hereinafter, also referred to as “filter X”) and filtering the resist composition.
Here, the term "filtration" refers to the commonly used chemical "filtration"("a film or phase of a porous material is used to permeate only the phase [gas or liquid] of a fluid and is semi-solid. Separating a phase or solid from a fluid phase ”Chemical Encyclopedia 9 Published July 31, 1958 Kyoritsu Publishing Co., Ltd.) In addition to the meaning, simply“ passing through a filter ”, that is, separating a film or the like. It also includes the case where the semi-solid phase or solid trapped by the separating member cannot be visually confirmed by passing the member.
Further, in the present invention, the resist composition to be passed through the filter may be a resist composition having the same concentration as the product, or a concept including a so-called "stock solution" having a relatively high solid content concentration before dilution. Further, in the present specification, when the undiluted solution and the product having the same concentration as the product are not particularly distinguished, it is described as a concept including the undiluted solution.

Also, "two or more types of filters" are intended to be filters with different surface critical tensions. That is, in step X, two or more types of filters having different surface critical tensions are used. Therefore, for example, other configurations such as the material and the pore diameter may be the same as long as the surface critical tension is different.

In the following, first, the filter X will be described, and then the procedure will be described.
The structure of the filter X is not particularly limited, and may be, for example, a film formed of a resin or the like (hereinafter, also referred to as “resin film”), and a resin film and a support member that supports the resin film. It may be composed of.

The material of the filter X is not particularly limited, and examples thereof include resins such as polyamide resin, polyolefin resin, and polyimide resin.
As the polyamide resin, nylon (nylons include nylon 6, nylon 66, nylon 46, and the like) is preferable.
As the polyolefin resin, polyethylene (PE) or polypropylene (PP) is preferable.
As the fluororesin, PTFE (polytetrafluoroethylene) is preferable.

Further, the filter X may be a resin film formed of a resin such as the above-mentioned lyamide resin, polyolefin resin, and polyimide resin, or may be composed of the above-mentioned resin film and a support member for supporting the above-mentioned resin film. It may be the one that has been made.

The pore size of the filter X is not particularly limited, but from the viewpoint of filtration efficiency, for example, 0.5 μm or less is preferable, 0.4 μm or less is more preferable, and 0.3 μm or less is further preferable. The lower limit of the pore diameter is not particularly limited, but is, for example, 0.001 μm or more. In the present specification, the "hole diameter" is intended to be the manufacturer's nominal diameter value.

Among the filters X, those having a critical surface tension of 10 to 90 din / cm are preferable in that the defect suppressing property of the formed pattern is more excellent.
Here, "critical surface tension" means the contact angle (θ) of a solid surface measured using a plurality of measurement standard liquid substances known as surface tension (γ), and the “cosθ” vs. “surface tension (γ)”. Is plotted (Zismann plot) and refers to the extrapolated value of the surface tension γ _LV when cos θ = 1 is given at the contact angle of solid / liquid.
The term "critical surface tension" as used herein is intended to be a manufacturer's nominal value. If there is no manufacturer's nominal value, water and iodomethane are used as measurement standard liquid substances, and the value measured by the above method is intended under the conditions of a temperature of 23 ° C. and a humidity of 40%.

When the critical surface tension of the filter X is 10 to 90 din / cm, it is presumed that the defect suppressing property of the formed pattern is more excellent for the following reasons.
When the surface tension of an object passing through the filter is close to the critical surface tension of the filter, the object has a high affinity with the filter and tends to be easily adsorbed by the filter. The surface tension of an object depends on the material. Only the desired object can be removed by a filter having a critical surface tension suitable for the surface tension peculiar to the material. More specifically, if a surfactant and bubbles are taken as an example, the surface tensions of the surfactant and the bubbles are different from each other. Therefore, if the critical surface tension of the filter is removed from the applicable range of the surface tension of the surfactant and controlled so as to be compatible with the surface tension of the bubbles, only the bubbles can be adsorbed without adsorbing the surfactant.
According to the study by the present inventors, when the critical surface tension of the filter X is 10 to 90 dyne / cm (particularly, when the critical surface tension of the filter X is 40 to 90 dyne / cm), the specific photoacid generator It is considered that the agglomerates are easily adsorbed by the filter X because they are compatible with the surface tension of the agglomerates caused by the above.

Examples of the filter having a critical surface tension of 10 to 90 dyne / cm include a nylon film supported by a support member (critical surface tension: 77 dyne / cm), a nylon film alone (critical surface tension: 46 dyne / cm), and a support member. Polyethylene membrane supported by (critical surface tension: 36 dyne / cm), PTFE supported by supporting member (critical surface tension: 28 dyne / cm), PTFE membrane alone (critical surface tension: 18.5 dyne / cm), and polyimide Examples thereof include a single membrane (critical surface tension: 45 dyne / cm).

The critical surface tension of at least one of the filters X is 40 to 90 dyne in that the agglomerates caused by the specific photoacid generator are easily adsorbed by the filter X and the defect suppression property of the formed pattern is more excellent. It is preferably / cm, and the critical surface tension of at least one of the filters X is 40 to 90 dyne / cm, and the critical surface tension of at least one of the filters X is 10 to 39 dyne / cm. Is more preferable.
Further, in step X, when two or more types of filters satisfying the critical surface tension of 10 to 90 din / cm are used, the critical surface tension of the filter having the highest critical surface tension and the critical surface tension of the filter having the smallest critical surface tension are used. The difference from the above is preferably 8 dyne / cm or more. The upper limit of the difference is not particularly limited, but is preferably 50 dyne / cm or less.

The number of filters X used in the step X is not particularly limited, but for example, two or more are preferable, and three or more are more preferable. The upper limit is not particularly limited, but for example, 10 or less is preferable, and 6 or less is more preferable. The critical surface tensions of the other filters X may be the same or different as long as the critical surface tensions of two or more of the filters X used in the step X are different from each other.

The specific procedure of step X will be described below.

Step X is preferably carried out in a temperature environment of 15 to 25 ° C.

In the step X, the differential pressure between the filters X (intentionally, the pressure loss before and after each filter X) is preferably 0.3 MPa or less, more preferably 0.2 MPa or less, and further preferably less than 0.1 MPa. The lower limit is not particularly limited, but 0 MPa can be mentioned.
Further, in step X, the differential pressure between before the resist composition passes through the filter on the most upstream side and after passing through the filter on the most downstream side among the filters arranged in the flow path is 0.3 MPa or less. Is preferable, 0.2 MPa or less is more preferable, and less than 0.1 MPa is further preferable. The lower limit is not particularly limited, but 0 MPa can be mentioned.

Specific examples of the process X include the following process X1 and the following process X2. Step X2 is preferable in that it is more excellent in defect suppression of the formed pattern.
Step X1: Single-passing type filtration step in which the resist composition is passed once through two or more types of filters X arranged in the flow path Step X2: Resist composition through two or more types of filters X arranged in the flow path. A circulating filtration step in which a resist composition that has passed through the filter X is further guided to the same filter and filtered again after passing through an object. That is, in step X1, two or more types of filters X are connected in series. Corresponding to the one-time liquid passing method in which the resist composition is passed through the system once, the step X2 is a circulation method in which the resist composition passing through the filter X is further guided to the same filter and circulated in the closed system. Applicable. When the purification method of the present invention is carried out by step X1, the step X1 may be repeated a plurality of times.

When the step X is the step X2, the number of cycles of the resist composition is, for example, 2 times or more, preferably 3 times or more. The upper limit is not particularly limited, but is, for example, 15 times or less, preferably 10 times or less.

The purification method of the present invention preferably includes a step Y of immersing the filter X used in the step X in an organic solvent before the step X in that the defect suppressing property of the formed pattern is more excellent.
The organic solvent is not particularly limited, but is propylene glycol monoalkyl ether carboxylate, propylene glycol monoalkyl ether, lactic acid ester, acetic acid ester, butyl butyrate, alkoxypropionic acid ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. And so on.

Examples of the propylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate.
As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) or propylene glycol monoethyl ether (PGEE) is preferable.
As the lactate ester, ethyl lactate, butyl lactate, or propyl lactate is preferable.
As the acetic acid ester, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl acetate, butyl formate, propyl formate, or 3-methoxybutyl acetate are preferable.
As the alkoxypropionic acid ester, methyl 3-methoxypropionate (MMP) or ethyl 3-ethoxypropionate (EEP) is preferable.
Chain ketones include 1-octanone, 2-octanone, 1-nonanonone, 2-nonanonone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl. Ketones, acetylacetones, acetonylacetones, ionones, diacetonyl alcohols, acetylcarbinol, acetophenones, methylnaphthyl ketones, or methylamyl ketones are preferred.
As the cyclic ketone, methylcyclohexanone, isophorone, or cyclohexanone is preferable.
As the lactone, γ-butyrolactone is preferable.
As the alkylene carbonate, propylene carbonate is preferable.

The immersion time is not particularly limited, but 6 to 24 hours is preferable.
The temperature of the organic solvent during immersion is not particularly limited, but is preferably 15 to 25 ° C.

The organic solvent is preferably an organic solvent contained in the resist composition because it is more excellent in suppressing defects in the formed pattern. That is, it is preferable that the organic solvent for immersing the filter X and the organic solvent contained in the resist composition are of the same type.

In the following, an example of the embodiment of step X will be described with reference to the drawings. 1 and 2 are schematic views of the apparatus used in step X.

The device of FIG. 1 is a device used when step X1 (one-time liquid passing method only once) is carried out as step X.
The apparatus of FIG. 1 has three filters X (filters X1, X2, X3), one of the three filters X has a critical surface tension of 10 to 39 dyne / cm, and one is critical. The surface tension is 40 to 90 dyne / cm.
In the apparatus of FIG. 3, the tank 1, the pump 2, the column 100 in which the filter X1 is installed, the column 200 in which the filter X2 is installed, and the column 300 in which the filter X3 is installed are the

flow paths

5, 6, 7, and 9. , And 10 are connected. Further, a flow meter 3 and a filling port 8 are installed in the flow path 7. By driving the pump 2, the resist composition filled in the tank 1 passes through the column 100, the column 200, and the column 300, and the resist composition that has passed through the column 300 is filled in the treatment liquid filling container 4.

The device of FIG. 2 is a device used when step X2 (circulation method) is carried out as step X.
The apparatus of FIG. 2 has three filters X (filters X4, X5, X6), one of the three filters X has a critical surface tension of 10 to 39 dyne / cm, and one is critical. The surface tension is 40 to 90 dyne / cm.
In the apparatus of FIG. 2, the tank 1, the pump 2, the column 400 in which the filter X4 is installed, the column 500 in which the filter X5 is installed, and the column 600 in which the filter X6 is installed are the

flow paths

5, 6, 7, and 9. , And 10 are connected.
Further, the flow path 7 is also connected to the tank 1, and by driving the pump 2, the resist composition contained in the tank 1 is circulated in the system. Further, a filling port 8 is installed in the flow path 7, and the resist composition that has undergone a predetermined circulation filtration step is filled in the treatment liquid filling container 4.
Here, the filling port 8 is often closed at the start of driving the pump so that a predetermined number of circulations can be achieved.
The number of circulations can be calculated using the flow meter 3 installed in the flow path 7.

Further, in step X, when the critical surface tension of at least one of the filters X is 40 to 90 din / cm and the critical surface tension of at least one of the filters X is 10 to 39 dyne / cm. It is preferable to arrange the filter having a critical surface tension of 40 to 90 din / cm on the upstream side of the filter having a critical surface tension of 10 to 39 din / cm.

In the purification method of the present invention, at least one of the filters X used in the step X is a filter having a critical surface tension of 10 to 39 din / cm in that the defect suppressing property of the formed pattern is more excellent. At least one of the filters has a critical surface tension of 40 to 90 din / cm, and the following purification method T1 is used, or the following purification method T2 (preferably the following purification method T3) is preferable.
Purification method T1: A step Y of immersing the filter X used in the step X1 in the organic solvent contained in the resist composition, which comprises the step X1 (single flow type filtration step) and before the step X1 is carried out. Purification method to be carried out.
Purification method T2: A purification method including step X2 (circulation type filtration step).
Purification method T3: A step Y including step X2 (circulation type filtration step) and immersing the filter X used in step X2 in the organic solvent contained in the resist composition is carried out before carrying out step X2. Purification method.

Next, the resist composition that is the subject of the purification method of the present invention will be described.

[Resist composition]
The resist composition (hereinafter, also referred to as “specific resist composition”) that is the subject of the purification method of the present invention includes a photoacid generator containing a specific photoacid generator, an acid-degradable resin (resin (A)), and Contains at least a solvent.
The specific resist composition may be a positive type resist composition or a negative type resist composition. Further, it may be a resist composition for alkaline development or a resist composition for organic solvent development.
The specific resist composition is typically a chemically amplified resist composition.
In the following, first, various components of the specific resist composition will be described in detail.

<Photoacid generator>
The specific resist composition contains a compound (photoacid generator) that generates an acid by irradiation with active light or radiation.
The content of the photoacid generator (when a plurality of types are contained, the total content thereof) in the specific resist composition is preferably 1.0 to 30.0% by mass with respect to the total solid content of the composition. More preferably, it is 5.0 to 20.0% by mass. The content of the photoacid generator here means, for example, that the photoacid generator contained in the specific resist composition is a photoacid generator other than the specific photoacid generator described later and the specific photoacid generator described later. In the case of two kinds of agents, the total content (mass%) of the specific photoacid generator and other photoacid generators is intended.
In addition, in this specification, "solid content" in a resist composition is intended as a component forming a resist film, and does not contain a solvent. Further, if it is a component forming a resist film, even if its property is liquid, it is regarded as a solid content.

The photoacid generator contains a compound (specific photoacid generator) selected from the group consisting of compounds (I) to (III) described later.
The content of the specific photoacid generator (the total content when a plurality of types are contained) is preferably 1.0 to 20.0% by mass, preferably 2.0 to 15.0, based on the total solid content of the composition. More preferably by mass.
The specific photoacid generator may be used alone or in combination of two or more.

The specific photoacid generator and other photoacid generators will be described below.

(Specific photoacid generator)
The specific photoacid generator is a compound selected from the group consisting of compounds (I) to (III) described later. Hereinafter, compounds (I) to (III) will be described.

<< Compound (I) >>
The compound (I) will be described below.
Compound (I): A compound having one of the following structural sites X and one of the following structural sites Y, and the following first acidic site and the following structure derived from the following structural site X by irradiation with active light or radiation. compound structure sites of generating an acid comprising the following second acidic site derived from the site Y X: anionic part a ₁ ^- consists of a cationic sites M ₁ ⁺ and Table in HA ₁ by and exposed to actinic rays or radiation the first structural portion structural site to form an acidic site Y that is: anionic part a ₂ ^- a cationic sites M ₂ ⁺ consists of a and by irradiation with actinic rays or radiation, the formed by the above structural moiety X The structural site forming the second acidic site represented by HA ₂ having a structure different from that of the first acidic site. However, the compound (I) satisfies the following condition I.
Condition I: In the compound (I), the compound PI in which the cation site M ₁ ⁺ in the structure site X and the cation site M ₂ ⁺ in the structure site Y are replaced with H ⁺ is contained in the structure site X. The acid dissociation constant a1 derived from the acidic site represented by HA ₁ , which is obtained by replacing the above-mentioned cation site M ₁ ⁺ with H ⁺ , and the above-mentioned cation site M ₂ ⁺ in the above structural site Y are replaced with H ^+. It has an acid dissociation constant a2 derived from an acidic moiety represented by HA ₂ , and the acid dissociation constant a2 is larger than the acid dissociation constant a1.
The acid dissociation constant a1 and the acid dissociation constant a2 are obtained by the above-mentioned method. More specifically, the acid dissociation constant a1 and the acid dissociation constant a2 of the compound PI refer to the compound PI (the compound PI is a compound having HA ₁ and HA ₂ ) when the acid dissociation constant of the compound PI is obtained. . corresponding to ") is" _{a 1} ^- and pKa when a compound "having a HA ₂ is the acid dissociation constant a1, the" _{a 1} ^- a compound having an HA ₂ "is" _{a 1} ^- and a ₂ ^- pKa when a compound "having a is an acid dissociation constant a2.
Further, the compound PI corresponds to an acid generated by irradiating compound (I) with active light or radiation.

In the compound PI, the difference between the acid dissociation constant a1 and the acid dissociation constant a2 is preferably 2.0 or more, more preferably 3.0 or more, in that the LWR performance of the formed pattern is more excellent. The upper limit of the difference between the acid dissociation constant a1 and the acid dissociation constant a2 is not particularly limited, but is, for example, 15.0 or less.

Further, in the above-mentioned compound PI, the acid dissociation constant a2 is, for example, 6.5 or less, and 2.0 or less is preferable in that the stability of the cation moiety of the compound (I) in the resist composition is more excellent. , 1.0 or less is more preferable. The lower limit of the acid dissociation constant a2 is, for example, −3.5 or higher, preferably −2.0 or higher.

Further, in the above compound PI, the acid dissociation constant a1 is preferably 2.0 or less, more preferably 0.5 or less, and even more preferably −0.1 or less, in that the LWR performance of the formed pattern is more excellent. The lower limit of the acid dissociation constant a1 is preferably -15.0 or higher.

The compound (I) is not particularly limited, and examples thereof include a compound represented by the following general formula (Ia).
M ₁₁ ⁺ A ₁₁ ^{－－} L ₁ － A ₁₂ ^－ M ₁₂ ⁺ (Ia)

In the general formula (Ia), _"M ^₁₁ + _A ¹¹ ^-" and _"A ^₁₂ - _M ¹² ^+" each correspond to structural moiety X and the structural moiety Y. Compound (Ia) by irradiation with actinic rays or _radiation, generates an acid represented by HA ₁₁ -L 1 _{-A 21} H. That is, _"M ^₁₁ + _A ¹¹ ^-" forms a first acidic moiety represented by _{HA 11,} _"A ^₁₂ - _M ¹² ^+" is _{HA 12} having a structure different from that of the aforementioned first acid sites It forms a second acidic moiety represented by.

In the general formula _{(Ia), M 11} ⁺ and _{M 12} ⁺ each independently represents an organic cation.
A ₁₁ ^- and _{A 12} ^- independently represents an anionic functional group. However, A ₁₂ ⁻ represents a structure different from the anionic functional group represented by A ₁₁ ⁻ .
L ₁ represents a divalent linking group.
However, Table above general formula _(Ia), in _{M 11} ⁺ and _{M 12} ⁺ organic cation represented by made by replacing the ^{H +} compound _{_{_{PIa (HA 11 -L 1 -A 12}}} H), at _{A 12} H The acid dissociation constant a2 derived from the acidic moiety to be produced is larger than the acid dissociation constant a1 derived from the acidic moiety represented by HA ₁₁ . The preferable values of the acid dissociation constant a1 and the acid dissociation constant a2 are as described above.

In the general formula _(Ia), the organic cation represented by _{M 11} ⁺ and _{M 12} ^+, are as described below.

A ₁₁ ^- and _{A 12} ^- The anionic functional group represented by, for example, groups represented by the following general formula (B-1) ~ formula (B-13).

In the general formulas (B-1), (B-2), (B-4), (B-5), and (B-12), ^RX1 represents a substituent.
As ^RX1 , a linear, branched, or cyclic alkyl group is preferable.
The alkyl group preferably has 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms.
The alkyl group may have a substituent. As the substituent, a fluorine atom or a cyano group is preferable. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group.
Further, in the above alkyl group, the carbon atom may be substituted with a carbonyl group.

In the general formula (B-3), ^RX4 represents a substituent.
The ^RX4 is preferably a linear, branched or cyclic alkyl group.
The alkyl group preferably has 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms.
The alkyl group may have a substituent. As the substituent, a fluorine atom or a cyano group is preferable. When ^RX4 is an alkyl group having a fluorine atom as a substituent, it is preferably not a perfluoroalkyl group.
Further, in the above alkyl group, the carbon atom may be substituted with a carbonyl group.

In the general formulas (B-7) and (B-11), ^RX2 represents a hydrogen atom or a substituent other than a fluorine atom and a perfluoroalkyl group.
The fluorine atom and a perfluoroalkyl substituents other than the groups represented by R ^X2, linear, branched, or cyclic alkyl group are preferred.
The alkyl group preferably has 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms.
The alkyl group may have a substituent other than the fluorine atom.

In the general formula (B-8), ^RXF1 represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, at least one of the plurality of ^RXF1 represents a fluorine atom or a perfluoroalkyl group.
The perfluoroalkyl group represented by ^RXF1 preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms.

In the general formula (B-10), ^RXF2 represents a fluorine atom or a perfluoroalkyl group.
The perfluoroalkyl group represented by ^RXF2 preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms.

In the general formula (B-9), n represents an integer of 0 to 4.

A ₁₁ ^- and _{A 12} ^- The combination of the anionic functional group represented by is not particularly limited, for _{example, A 11} ^- is a group represented by the general formula (B-8) or (B-10) _{If, A 12} ^- Table the anionic functional group represented by the general formula (B-1) ~ (B -7), (B-9), or (B-11) ~ (B -13) include groups, a ₁₁ ^- when is a group represented by the general formula _{(B-7), a 12} - as the anionic functional group represented by the table in the general formula (B-6) The groups to be used are mentioned.

In the general formula (Ia), the divalent linking group represented by L ₁ is not particularly limited, and is -CO-, -NR-, -CO-, -O-, or an alkylene group (preferably having 1 to 1 to carbon atoms). 6. Linear or branched chain), cycloalkylene group (preferably 3 to 15 carbon atoms), alkenylene group (preferably 2 to 6 carbon atoms), divalent aliphatic heterocyclic group (at least one) A 5- to 10-membered ring having an N atom, an O atom, an S atom, or a Se atom in the ring structure is preferable, a 5- to 7-membered ring is more preferable, and a 5- to 6-membered ring is further preferable), and a plurality of these. Examples thereof include a divalent linking group in which The above R may be a hydrogen atom or a monovalent substituent. The monovalent substituent is not particularly limited, but for example, an alkyl group (preferably 1 to 6 carbon atoms) is preferable.
These divalent linking groups may further include a group selected from the group consisting of -S-, -SO-, and -SO _2- .
Further, the alkylene group, the cycloalkylene group, the alkenylene group, and the divalent aliphatic heterocyclic group may be substituted with a substituent. Examples of the substituent include a halogen atom (preferably a fluorine atom).

In the general formula _(Ia), it will be described in detail preferred embodiments of the organic cation represented by _{M 11} ⁺ and _{M 12} ^+.
The organic cation represented by M ₁₁ ⁺ and _{M 12} ⁺ are each independently formula (Zai) organic cation represented by (cation (Zai)) or the general formula organic cation (cation represented by (ZaII) (ZaII)) is preferable.

In the above general formula (ZaI)
R ²⁰¹ , R ²⁰² , and R ²⁰³ each independently represent an organic group.
The carbon number of the organic group as R ²⁰¹ , R ²⁰² , and R ²⁰³ is usually 1 to 30, preferably 1 to 20. Further, 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 group, an amide group, or a carbonyl group. The two of the group formed by bonding of the R ²⁰¹ ~ ^{R 203,} for example, an alkylene group (e.g., butylene and pentylene), and _{_{_{-CH 2 -CH 2 -O-CH 2}}} -CH 2 - is Can be mentioned.

As a preferable embodiment of the organic cation in the general formula (ZaI), the organic cation represented by the cation (ZaI-1), the cation (ZaI-2), and the general formula (ZaI-3b) (cation (ZaI-)) described later will be described. Examples thereof include 3b)) and an organic cation (cation (ZaI-4b)) represented by the general formula (ZaI-4b).

First, the cation (ZaI-1) will be described.
The cation (ZaI-1) is an aryl sulfonium cation in which at least one of R ²⁰¹ to R ²⁰³ of the above general formula (ZaI) is an aryl group.
As the aryl sulfonium cation, 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.
Further, one of R ₂₀₁ to R ₂₀₃ may be an aryl group, and the remaining two of R ²⁰¹ to R ²⁰³ may be bonded to form a ring structure, and an oxygen atom and a sulfur atom may be formed in the ring. It may contain an ester group, an amide group, or a carbonyl group. As a group formed by bonding two of R ²⁰¹ to R ²⁰³ , for example, one or more methylene groups are substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group. also an alkylene group (e.g., butylene group, pentylene group, or _{_{_{-CH 2 -CH 2 -O-CH 2}}} -CH 2 -) and the like.
Examples of the aryl sulfonium cation include a triaryl sulfonium cation, a diallyl alkyl sulfonium cation, an aryl dialkyl sulfonium cation, a diallyl cycloalkyl sulfonium cation, and an aryl dicycloalkyl sulfonium cation.

As the aryl group contained in the arylsulfonium cation, a phenyl group or a naphthyl group is preferable, and a phenyl group is more preferable. 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 pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, benzothiophene residues and the like. When the aryl sulfonium cation 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 cation has as needed is a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a branched alkyl group having 3 to 15 carbon atoms. Cycloalkyl group is preferable, and examples thereof include a methyl group, 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 may independently have an alkyl group (for example, 1 to 15 carbon atoms) and a cycloalkyl group (for example, carbon number of carbon atoms). 3 to 15), aryl groups (for example, 6 to 14 carbon atoms), alkoxy groups (for example, 1 to 15 carbon atoms), cycloalkyl alkoxy groups (for example, 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. Be done.
The substituent may further have a substituent when possible, and for example, the alkyl group may have a halogen atom as a substituent and may be an alkyl halide group such as a trifluoromethyl group. ..

Next, the cation (ZaI-2) will be described.
The cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in the formula (ZaI) independently represent an organic group having no aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ generally has 1 to 30 carbon atoms, and 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, and are linear or branched 2-oxoalkyl groups, 2-oxocycloalkyl groups, or alkoxy groups. A carbonyl methyl group is more preferred, and a linear or branched 2-oxoalkyl group is even more preferred.

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

Next, the cation (ZaI-3b) will be described.
The cation (ZaI-3b) is a cation represented by the following general formula (ZaI-3b).

In the general formula (ZaI-3b),
R _1c to R _5c are independently hydrogen atom, alkyl group, cycloalkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, alkylcarbonyloxy group, cycloalkylcarbonyloxy group, halogen atom, hydroxyl group. , Nitro group, alkylthio group, or arylthio group.
R _6c and R _7c independently represent a hydrogen atom, an alkyl group (t-butyl group, etc.), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.
R _x and R _y each independently represent 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 combined to form a ring, respectively. , This ring may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the ring include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, and a polycyclic fused ring formed by combining two or more of these rings. Examples of the ring include a 3- to 10-membered ring, preferably a 4- to 8-membered ring, and more preferably a 5- or 6-membered ring.

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 an alkylene group such as a butylene group and a pentylene group. The methylene group in the alkylene group may be substituted with a hetero atom such as an oxygen atom.
As the group formed by bonding R _5c and R _6c , and R _5c and R _x , a single bond or an alkylene group is preferable. Examples of the alkylene group include a methylene group and an ethylene group.

Next, the cation (ZaI-4b) will be described.
The cation (ZaI-4b) is a cation represented by the following general formula (ZaI-4b).

In the general formula (ZaI-4b),
l represents an integer of 0 to 2.
r represents an integer from 0 to 8.
R ₁₃ is a group having a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, or a cycloalkyl group (the cycloalkyl group itself may be used, and a group containing a cycloalkyl group as a part). May be). These groups may have substituents.
R ₁₄ is a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group (the cycloalkyl group itself may be a cycloalkyl group). It may be a group containing a part of). These groups may have substituents. When a plurality of R ₁₄ are present, each independently represents the above group such as a hydroxyl group.
R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. These groups may have substituents. Bonded to two R ₁₅ each other may form a ring. When two R ₁₅ are combined to form a ring together, in the ring skeleton may contain a hetero atom such as an oxygen atom, or a nitrogen atom. In one embodiment, two R ₁₅ is an alkylene group, preferably bonded together to form a ring structure.

In the general formula (ZaI-4b), the alkyl groups of R ₁₃ , R ₁₄ , and R ₁₅ are linear or branched chain. The alkyl group preferably has 1 to 10 carbon atoms. As the alkyl group, a methyl group, an ethyl group, an n-butyl group, a t-butyl group and the like are more preferable.

Next, the general formula (ZaII) will be described.
In the general formula (ZaII), R ²⁰⁴ and R ²⁰⁵ each independently represent an aryl group, an alkyl group or a cycloalkyl group.
As the aryl group of R ²⁰⁴ and R ^205, a phenyl group or a naphthyl group is preferable, and a phenyl group is more preferable. The aryl group of R ²⁰⁴ and R ²⁰⁵ may be an aryl group having a heterocycle having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
Examples of the alkyl group and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ include a linear alkyl group having 1 to 10 carbon atoms or a branched chain alkyl group having 3 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, etc.). A butyl group or a pentyl group) or a cycloalkyl group having 3 to 10 carbon atoms (for example, a cyclopentyl group, a cyclohexyl group, or a norbornyl group) is preferable.

The aryl group, alkyl group, and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may each independently have a substituent. Examples of the substituent that the aryl group, alkyl group, and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may have include an alkyl group (for example, 1 to 15 carbon atoms) and a cycloalkyl group (for example, 3 to 15 carbon atoms). 15), aryl groups (for example, 6 to 15 carbon atoms), alkoxy groups (for example, 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like can be mentioned.

≪Compound (II) ≫
Next, compound (II) will be described.
Compound (II): A compound having two or more of the structural sites X and the structural site Y, and having two first acidic sites derived from the structural site X by irradiation with active light or radiation. A compound that generates an acid containing the above and the second acidic moiety derived from the structural moiety Y. However, the compound (II) satisfies the following condition II.
Condition II: In the compound (II), the compound PII obtained by replacing the cation site M ₁ ⁺ in the structural site X and the cation site M ₂ ⁺ in the structural site Y with H ⁺ is contained in the structural site X. The acid dissociation constant a1 derived from the acidic site represented by HA _{1 in} which the cation site M ₁ ⁺ is replaced with H ⁺ , and the HA obtained by replacing the cation site M ₂ ⁺ in the structural site Y with H ^+. _It has an acid dissociation constant a2 derived from the acidic moiety represented by ₂ , and the acid dissociation constant a2 is larger than the acid dissociation constant a1.
The acid dissociation constant a1 and the acid dissociation constant a2 are obtained by the above-mentioned method.
Here, the acid dissociation constant a1 and the acid dissociation constant a2 of the compound PII will be described more specifically. When the compound (II) is, for example, a compound that generates an acid having two first acidic sites derived from the structural site X and one second acidic site derived from the structural site Y. , Compound PII corresponds to "a compound having _two HA ₁ and HA ₂ ". If asked for the acid dissociation constant of the compound PII, compound PII is ^- a pKa of acid dissociation constant a1 when the "one of _{A 1} and one HA ₁ and HA ₂ with a compound of", "two a ₁ ^- and HA ₂ compound having the "is" two _{a 1} ^- and _{a 2} ^- pKa when a compound "having a is an acid dissociation constant a2. That is, when the compound PII has a plurality of acid dissociation constants derived from the acidic dissociation constant represented by HA _{1 formed} by replacing the cation site M ₁ ⁺ in the structural site X with H ⁺ , the smallest value is acid. It is regarded as the dissociation constant a1.

Further, the compound PII corresponds to an acid generated by irradiating compound (II) with active light or radiation.
In addition, compound (II) may have a plurality of the structural sites Y.

In the compound PII, the difference between the acid dissociation constant a1 and the acid dissociation constant a2 is preferably 2.0 or more, more preferably 3.0 or more, in that the LWR performance of the formed pattern is more excellent. The upper limit of the difference between the acid dissociation constant a1 and the acid dissociation constant a2 is not particularly limited, but is, for example, 15.0 or less.

Further, in the above compound PII, the acid dissociation constant a2 is, for example, 6.5 or less, and 2.0 or less is preferable in that the stability of the cation moiety of the compound (I) in the resist composition is more excellent. , 1.0 or less is more preferable. The lower limit of the acid dissociation constant a2 is, for example, −3.5 or higher, preferably −2.0 or higher.

Further, in the above-mentioned compound PII, the acid dissociation constant a1 is preferably 2.0 or less, more preferably 0.5 or less, and further preferably -0.1 or less in that the LWR performance of the formed pattern is more excellent. The lower limit of the acid dissociation constant a1 is preferably -15.0 or higher.

The compound (II) is not particularly limited, and examples thereof include a compound represented by the following general formula (IIa).

In the general formula (Ia), _"M ^₂₁ + _A ²¹ ^-" and _"A ^₂₂ - ⁺ _M ^22" each correspond to structural moiety X and the structural moiety Y. The compound (IIa) generates an acid represented by the following general formula (IIa-1) by irradiation with active light rays or radiation. That is, _"M ^₂₁ + _A ²¹ ^-" forms a first acidic moiety represented by _{HA 21,} _"A ^₂₂ - _M ²² ^+" is a structure different from that of the first acid sites _{HA 22} It forms a second acidic moiety represented by.

In the general formula _(IIa), ^⁺ _{M 21} ⁺ and _{M 22} each independently represents an organic cation.
A ₂₁ ^- and _{A 22} ^- independently represents an anionic functional group. However, A ₂₂ ⁻ represents a structure different from the anionic functional group represented by A ₂₁ ⁻ .
L ₂ represents a (n1 + n2) valent organic group.
n1 represents an integer of 2 or more, and n2 represents an integer of 1 or more.
However, the following general formula _(IIa), corresponds to the compound represented by Compound PIIa comprising replacing organic cation represented by _{M 21} ⁺ and _{M 22} ⁺ to ^{H +} (the general formula (IIa-1) ), The acid dissociation constant a2 derived from the acidic moiety represented by A ₂₂ H is larger than the acid dissociation constant a1 derived from the acidic moiety represented by HA ₂₁ . The preferable values of the acid dissociation constant a1 and the acid dissociation constant a2 are as described above.

In the general formula _{^{_{^{(IIa), M 21 +,}}}} M 22 +, A 21 -, and _{A 22} ^- is in each above-mentioned general formula _{^{_{^{(Ia) M 11 +, M}}}} 12 +, A 11 -, and A ₁₂ ^- in the above formula, preferred embodiments are also the same.
In the general formula (IIa), n1 pieces of _{M 21} ⁺ each other, n1 pieces of _{A 21} ⁺ each other, represent each mutually identical groups.

In the above general formula (IIa), the (n1 + n2) valent organic group represented by L ₂ is not particularly limited, and examples thereof include groups represented by the following (A1) and the following (A2). Incidentally, in the following (A1) and (A2), at least two of * _{A 21} ^- represents a bonding position to at least one of * the _{A 22} ^- represents a bonding site to the.

In the above (A1) and (A2), T ¹ represents a trivalent hydrocarbon ring group or a trivalent heterocyclic group, and T ² is a carbon atom, a tetravalent hydrocarbon ring group, or a tetravalent. Represents the heterocyclic group of.

The hydrocarbon ring group may be an aromatic hydrocarbon ring group or an aliphatic hydrocarbon ring group. The number of carbon atoms contained in the hydrocarbon ring group is preferably 6 to 18, and more preferably 6 to 14.
The heterocyclic group may be an aromatic heterocyclic group or an aliphatic heterocyclic group. The heterocycle is preferably a 5- to 10-membered ring having at least one N atom, an O atom, an S atom, or a Se atom in the ring structure, more preferably a 5- to 7-membered ring, and a 5- to 6-membered ring. Rings are more preferred.

Further, in the above (A1) and (A2), L ²¹ and L ²² independently represent a single bond or a divalent linking group, respectively.
The divalent linking group represented by L ²¹ and L ²² has the same meaning as the divalent linking group represented by L ₁ in the general formula (Ia), and the preferred embodiment is also the same.
n1 represents an integer of 2 or more. The upper limit is not particularly limited, but is, for example, 6 or less, preferably 4 or less, and more preferably 3 or less.
n2 represents an integer of 1 or more. The upper limit is not particularly limited, but is, for example, 3 or less, preferably 2 or less.

≪Compound (III) ≫
Next, compound (III) will be described.
Compound (III): A compound having two or more of the structural site X and the following structural site Z, wherein the first acidic site derived from the structural site X is 2 by irradiation with active light or radiation. A compound that generates an acid containing one or more of the above structural site Z Structural site Z: Nonionic site capable of neutralizing the acid

The nonionic organic moiety capable of neutralizing the acid in the structural moiety Z is not particularly limited, and for example, a moiety containing a functional group having a group or an electron capable of electrostatically interacting with a proton (preferably organic). Site) is preferable.
As a functional group having a group or an electron capable of electrostatically interacting with a proton, a functional group having a macrocyclic structure such as a cyclic polyether or a nitrogen atom having an unshared electron pair that does not contribute to π conjugation is used. Examples thereof include functional groups having. 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 shown in the following formula.

Substructures of functional groups having groups or electrons that can electrostatically interact with protons include, for example, crown ether structures, aza crown ether structures, 1-3 amine structures, pyridine structures, imidazole structures, and pyrazine structures. Etc., and among them, a primary to tertiary amine structure is preferable.

In the compounds PIII which the compound in (III) formed by replacing the cationic sites _M ^{1 +} in the structural moiety X to ^{H +,} HA ₁ comprising substituting the cationic sites _M ^{1 +} in the structural moiety X to ^{H +} The acid dissociation constant a1 derived from the acidic moiety represented by is preferably 2.0 or less, more preferably 0.5 or less, and further -0.1 or less in that the LWR performance of the formed pattern is more excellent. preferable. The lower limit of the acid dissociation constant a1 is preferably -15.0 or higher.
When compound PIII has a plurality of acid dissociation constants derived from the acidic site represented by HA _{1 in} which the cation site M ₁ ⁺ in the structural site X is replaced with H ⁺ , the smallest value is acid. It is regarded as the dissociation constant a1.
That is, when compound (III) is, for example, a compound that generates an acid having two first acidic sites derived from the structural site X and the structural site Z, the compound PIII is "two HA _1". It corresponds to "a compound having." If asked for the acid dissociation constant of the compound PIII, compound PIII is ^- pKa when the "one of _{A 1} and a compound having one HA _1" is an acid dissociation constant a1. That is, when compound PIII has a plurality of acid dissociation constants derived from the acidic site represented by HA _{1 in} which the cation site M ₁ ⁺ in the structural site X is replaced with H ⁺ , the smallest value is acid. It is regarded as the dissociation constant a1.
In the compound (III), the compound PIII in which the cation site M ₁ ⁺ in the structural site X is replaced with H ⁺ is, for example, a compound in which the compound (III) is represented by the compound (IIIa) described later. If, HA _31- L _3- N (R ^2X ) -L _4- A ₃₁ H corresponds.

The compound (III) is not particularly limited, and examples thereof include a compound represented by the following general formula (IIIa).

In the general formula (IIIa), _"M ^₃₁ + _A ³¹ ^-" corresponds to the structural moiety X. Compound (IIIa) produces an acid represented by HA _31- L _3- N (R ^2X ) -L _4- A ₃₁ H by irradiation with active light or radiation. That is, _"M ^₃₁ + _A ³¹ ^-" forms a first acidic moiety represented by _{HA 31.}

In the general formula _{(IIIa), M 31} ⁺ represents an organic cation.
A ₃₁ ^- represents an anionic functional group.
L ₃ and L ₄ each independently represent a divalent linking group.
R ^2X represents a monovalent substituent.

In the general formula (IIIa), M ₃₁ ⁺ and A ₃₁ ⁻ are synonymous with M ₁₁ ⁺ and A ₁₁ ⁻ in the general formula (Ia) described above, respectively, and the preferred embodiments are also the same.
In the general formula (IIIa), L ₃ and L ₄ are synonymous with L ₁ in the general formula (Ia) described above, and the preferred embodiments are also the same.
In the general formula (IIIa), two _{M 31} ⁺ each other, and two _{A 31} ^- each other, represent each mutually identical groups.

In the general formula (IIIa), the monovalent substituent represented by R ^2X is not particularly limited, and for example, -CH _2- is -CO-, -NH-, -O-, -S-,-. SO-, and -SO 2 _- may be substituted with one or more combinations selected from the group consisting of an alkyl group (preferably may be 1-10 either linear or branched carbon atoms. ), Cycloalkyl group (preferably 3 to 15 carbon atoms), alkenyl group (preferably 2 to 6 carbon atoms) and the like.
Further, the alkylene group, the cycloalkylene group, and the alkenylene group may be substituted with a substituent.

The molecular weight of the compounds represented by the compounds (I) to (III) is preferably 300 or more and less than 3000, more preferably 500 to 2000, and even more preferably 700 to 1500.

The following are preferable examples of the compounds represented by the above compounds (I) to (III).

(Other photoacid generators)
The specific resist composition may contain no particular limitation as other photoacid generators other than the specific photoacid generator. Examples of other photoacid generators include paragraphs [0125] to [0319] of US Patent Application Publication No. 2016/0070167A1 and paragraphs [0083] to [0094] of US Patent Application Publication No. 2015/0004544A1. , U.S. Patent Application Publication No. 2016/0237190A1, paragraphs [0323] to [0402], and Japanese Patent Application Laid-Open No. 2018-155788, disclosed in paragraphs [0074] to [0122] and [0137] to [0146]. The known compound described above can be preferably used.

When the specific resist composition contains other photoacid generators, the content of the other photoacid generators is preferably 0.1 to 10.0% by mass with respect to the total solid content of the composition.
The above other photoacid generators may be used alone or in combination of two or more. When two or more kinds are used, the total content thereof is preferably within the above-mentioned suitable content range.

<Acid-degradable resin (resin (A))>
The specific resist composition contains a resin (hereinafter, also referred to as "acid-decomposable resin" or "resin (A)") which is decomposed by the action of an acid to increase the polarity.
That is, in the pattern forming method of the present invention, typically, when an alkaline developer is used as the developer, a positive pattern is preferably formed, and when an organic developer is used as the developer, a positive pattern is preferably formed. , A negative pattern is preferably formed.
The resin (A) usually contains a group that is decomposed by the action of an acid and whose polarity is increased (hereinafter, also referred to as “acid-degradable group”), and preferably contains a repeating unit having an acid-decomposable group.

≪Repeating unit with acid-degradable group≫
The acid-degradable group refers to a group that is decomposed by the action of an acid to form a polar group. The acid-degradable group preferably has a structure in which the polar group is protected by a leaving group that is eliminated by the action of an acid. That is, the resin (A) has a repeating unit having a group which is decomposed by the action of an acid to produce a polar group. The polarity of the resin having this repeating unit is increased by the action of the acid, the solubility in the alkaline developer is increased, and the solubility in the organic solvent is decreased.
As the polar group, an alkali-soluble group is preferable, and for example, a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, a sulfonylimide group, (alkylsulfonyl) (alkylcarbonyl) methylene. Group, (alkylsulfonyl) (alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) Examples thereof include an acidic group such as a methylene group and a tris (alkylsulfonyl) methylene group, and an alcoholic hydroxyl group.
Among them, as the polar group, a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group is preferable.

Examples of the leaving group that are eliminated by the action of an acid include groups represented by the formulas (Y1) to (Y4).
Equation (Y1): -C (Rx ₁ ) (Rx ₂ ) (Rx ₃ )
Equation (Y2): -C (= O) OC (Rx ₁ ) (Rx ₂ ) (Rx ₃ )
Equation (Y3): -C (R ₃₆ ) (R ₃₇ ) (OR ₃₈ )
Formula (Y4): -C (Rn) (H) (Ar)

In formulas (Y1) and (Y2), Rx ₁ to Rx ₃ are independently alkyl groups (linear or branched chain), cycloalkyl groups (monocyclic or polycyclic), and alkenyl groups (straight chain). (Orchid or branched chain), or aryl group (monocyclic or polycyclic). When all of Rx ₁ to Rx ₃ are alkyl groups (linear or branched chain), it is preferable that at least two of Rx ₁ to Rx ₃ are methyl groups.
Among them, Rx ₁ to Rx ₃ preferably independently represent a linear or branched alkyl group, and Rx ₁ to Rx ₃ each independently represent a linear alkyl group. Is more preferable.
Two of Rx ₁ to Rx ₃ may be combined to form a monocyclic or polycyclic ring.
As the alkyl group of Rx ₁ to Rx ₃ , an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group is preferable. ..
Examples of the cycloalkyl group of Rx ₁ to Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, and a polycyclic ring such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Cycloalkyl group is preferred.
As the aryl group of Rx ₁ to Rx _3, an aryl group having 6 to 10 carbon atoms is preferable, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
As the alkenyl group of Rx ₁ to Rx ₃ , a vinyl group is preferable.
A cycloalkyl group is preferable as the ring formed by bonding two of Rx ₁ to Rx ₃ . The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is a cyclopentyl group, a monocyclic cycloalkyl group such as a cyclohexyl group, or a norbornyl group, a tetracyclodecanyl group, or a tetracyclododecanyl. A polycyclic cycloalkyl group such as a group or an adamantyl group is preferable, and a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable.
The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is, for example, a group in which one of the methylene groups constituting the ring has a hetero atom such as an oxygen atom, a hetero atom such as a carbonyl group, or vinylidene. It may be replaced by a base. Further, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
The group represented by the formula (Y1) or the formula (Y2) is, for example, an embodiment in which Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to form the above-mentioned cycloalkyl group. Is preferable.

In formula (Y3), R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group. R ₃₇ and R ₃₈ may be combined with each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group and the like. It is also preferable that R ₃₆ is a hydrogen atom.
The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom and / or a group having a heteroatom such as a carbonyl group. For example, in the above alkyl group, cycloalkyl group, aryl group, and aralkyl group, for example, one or more methylene groups are replaced with a group having a hetero atom such as an oxygen atom and / or a hetero atom such as a carbonyl group. May be good.
Further, R ₃₈ may be bonded to each other with another substituent contained in the main chain of the repeating unit to form a ring. The group formed by bonding R ₃₈ and another substituent of the main chain of the repeating unit to each other is preferably an alkylene group such as a methylene group.

As the formula (Y3), a group represented by the following formula (Y3-1) is preferable.

Here, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group in which these are combined (for example, a group in which an alkyl group and an aryl group are combined).
M represents a single bond or a divalent linking group.
Q is an alkyl group that may contain a hetero atom, a cycloalkyl group that may contain a hetero atom, an aryl group that may contain a hetero atom, an amino group, an ammonium group, a mercapto group, a cyano group, and an aldehyde. Represents a group or a group in which these are combined (for example, a group in which an alkyl group and a cycloalkyl group are combined).
In the alkyl group and cycloalkyl group, for example, one of the methylene groups may be replaced with a hetero atom such as an oxygen atom or a group having a hetero atom such as a carbonyl group.
It is preferable that _one of L ₁ and L ₂ is a hydrogen atom and the other is an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkylene group and an aryl group are combined.
Q, M, and at least two members to the ring (preferably, 5-membered or 6-membered ring) L ₁ may be formed.
From the viewpoint of pattern miniaturization, L ₂ is preferably a secondary or tertiary alkyl group, and more preferably a tertiary alkyl group. Examples of the secondary alkyl group include an isopropyl group, a cyclohexyl group and a norbornyl group, and examples of the tertiary alkyl group include a tert-butyl group and an adamantan group. In these aspects, since Tg (glass transition temperature) and activation energy are high, fog can be suppressed in addition to ensuring the film strength.

In the formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be combined with each other to form a non-aromatic ring. Ar is more preferably an aryl group.

In the desorbing group that protects the polar group, when the non-aromatic ring is directly bonded to the polar group (or its residue), in the non-aromatic ring, from the viewpoint of excellent acid decomposition property of the repeating unit, It is also preferable that the ring member atom adjacent to the ring member atom directly bonded to the polar group (or its residue) does not have a halogen atom such as a fluorine atom as a substituent.

Other desorbing groups eliminated by the action of an acid include a 2-cyclopentenyl group having a substituent (alkyl group, etc.) such as a 3-methyl-2-cyclopentenyl group, and 1,1,4. , A cyclohexyl group having a substituent (alkyl group, etc.) such as 4-tetramethylcyclohexyl group may be used.

As the repeating unit having an acid-degradable group, the repeating unit represented by the formula (A) is also preferable.

L ₁ represents a divalent linking group which may have a fluorine atom or an iodine atom, and R ₁ is an alkyl group which may have a hydrogen atom, a fluorine atom, an iodine atom, a fluorine atom or an iodine atom. , Or an aryl group which may have a fluorine atom or an iodine atom, and R ₂ represents a desorbing group which is eliminated by the action of an acid and may have a fluorine atom or an iodine atom. However, at least one of L ₁ , R ₁ , and R ₂ has a fluorine atom or an iodine atom.
L ₁ represents a divalent linking group which may have a fluorine atom or an iodine atom. The fluorine atom or a linking group may divalent have a iodine atom, -CO -, - O -, - S -, - SO -, - SO 2 -, have a fluorine atom or an iodine atom Examples thereof include a hydrocarbon group (for example, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, etc.), and a linking group in which a plurality of these are linked. Among them, as the L _1, -CO-, or - arylene - fluorine atom or an alkylene group having iodine atom - are preferred.
As the arylene group, a phenylene group is preferable.
The alkylene group may be linear or branched chain. The number of carbon atoms of the alkylene group is not particularly limited, but 1 to 10 is preferable, and 1 to 3 is more preferable.
The total number of fluorine atoms and iodine atoms contained in the alkylene group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

R ₁ represents an alkyl group which may have a hydrogen atom, a fluorine atom, an iodine atom, a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom.
The alkyl group may be linear or branched. The number of carbon atoms of the alkyl group is not particularly limited, but 1 to 10 is preferable, and 1 to 3 is more preferable.
The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3.
The alkyl group may contain a hetero atom such as an oxygen atom other than the halogen atom.

R ₂ represents a leaving group that is eliminated by the action of an acid and may have a fluorine atom or an iodine atom.
Among them, examples of the leaving group include groups represented by the formulas (Z1) to (Z4).
Equation (Z1): -C (Rx ₁₁ ) (Rx ₁₂ ) (Rx ₁₃ )
Equation (Z2): -C (= O) OC (Rx ₁₁ ) (Rx ₁₂ ) (Rx ₁₃ )
Equation (Z3): -C (R ₁₃₆ ) (R ₁₃₇ ) (OR ₁₃₈ )
Equation (Z4): -C (Rn ₁ ) (H) (Ar ₁ )

In formulas (Z1) and (Z2), Rx ₁₁ to Rx ₁₃ are alkyl groups (linear or branched), fluorine atoms or iodine atoms which may independently have fluorine atoms or iodine atoms, respectively. It has a cycloalkyl group (monocyclic or polycyclic) that may have a fluorine atom or an alkenyl group that may have a fluorine atom or an iodine atom (linear or branched chain), or a fluorine atom or an iodine atom. Represents an aryl group (monocyclic or polycyclic) which may be used. When all of Rx ₁₁ to Rx ₁₃ are alkyl groups (linear or branched chain), it is preferable that at least two of Rx ₁₁ to Rx ₁₃ are methyl groups.
Rx ₁₁ to Rx ₁₃ are the same as Rx ₁ to Rx _{3 in} (Y1) and (Y2) described above, except that they may have a fluorine atom or an iodine atom, and are an alkyl group or a cycloalkyl group. , Alkyl group, and aryl group are the same as the definition and preferred range.

In the formula (Z3), R ₁₃₆ to R ₁₃₈ each independently represent a hydrogen atom or a monovalent organic group which may have a fluorine atom or an iodine atom. R ₁₃₇ and R ₁₃₈ may be combined with each other to form a ring. The monovalent organic group which may have a fluorine atom or an iodine atom includes an alkyl group which may have a fluorine atom or an iodine atom, and a cycloalkyl group which may have a fluorine atom or an iodine atom. , An aryl group that may have a fluorine atom or an iodine atom, an aralkyl group that may have a fluorine atom or an iodine atom, and a group that combines these (for example, an alkyl group and a cycloalkyl group are combined. Group).
The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a hetero atom such as an oxygen atom in addition to the fluorine atom and the iodine atom. That is, the alkyl group, cycloalkyl group, aryl group, and aralkyl group may be replaced with, for example, one of the methylene groups by a heteroatom such as an oxygen atom or a group having a heteroatom such as a carbonyl group.
Further, R ₁₃₈ may be bonded to each other with another substituent contained in the main chain of the repeating unit to form a ring. In this case, the group formed by bonding R ₁₃₈ and another substituent of the main chain of the repeating unit to each other is preferably an alkylene group such as a methylene group.

As the formula (Z3), a group represented by the following formula (Z3-1) is preferable.

Here, L ₁₁ and L ₁₂ may independently have a hydrogen atom; a hetero atom selected from the group consisting of a fluorine atom, an iodine atom and an oxygen atom; a fluorine atom, an iodine atom and an alkyl group. A cycloalkyl group which may have a hetero atom selected from the group consisting of oxygen atoms; an aryl group which may have a hetero atom selected from the group consisting of a fluorine atom, an iodine atom and an oxygen atom; or It represents a group in which these are combined (for example, a group in which an alkyl group and a cycloalkyl group are combined, which may have a hetero atom selected from the group consisting of a fluorine atom, an iodine atom and an oxygen atom).
M ₁ represents a single bond or a divalent linking group.
Q ₁ represents a fluorine atom, an alkyl group which may have a hetero atom selected from the group consisting of iodine atoms and an oxygen atom; Yes fluorine atom, a hetero atom selected from the group consisting of iodine atoms and an oxygen atom May be cycloalkyl group; aryl group selected from the group consisting of fluorine atom, iodine atom and oxygen atom; amino group; ammonium group; mercapto group; cyano group; aldehyde group; or a group combining these (for example). , A group combining an alkyl group and a cycloalkyl group, which may have a heteroatom selected from the group consisting of a fluorine atom, an iodine atom and an oxygen atom).

In formula (Y4), Ar ₁ represents an aromatic ring group which may have a fluorine atom or an iodine atom. Rn ₁ is an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. Represents. Rn ₁ and Ar ₁ may be combined with each other to form a non-aromatic ring.

As the repeating unit having an acid-degradable group, a repeating unit represented by the general formula (AI) is also preferable.

In the general formula (AI)
Xa ₁ represents a hydrogen atom or an alkyl group which may have a substituent.
T represents a single bond or a divalent linking group.
Rx ₁ to Rx ₃ are independently alkyl groups (linear or branched chain), cycloalkyl groups (monocyclic or polycyclic), alkenyl groups (linear or branched chain), or aryl (linear or branched chain). Represents a monocyclic or polycyclic) group. However, when all of Rx ₁ to Rx ₃ are alkyl groups (linear or branched chain), it is preferable that at least two of Rx ₁ to Rx ₃ are methyl groups.
Two of Rx ₁ to Rx ₃ may be bonded to form a monocyclic or polycyclic (monocyclic or polycyclic cycloalkyl group, etc.).

Represented by xa _1, as the alkyl group which may have a substituent group, include groups represented by methyl group or _-CH 2 _{-R 11.} R ₁₁ represents a halogen atom (fluorine atom, etc.), a hydroxyl group, or a monovalent organic group. For example, the halogen atom may be substituted, an alkyl group having 5 or less carbon atoms, or a halogen atom may be substituted. Examples thereof include an acyl group having 5 or less carbon atoms and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkyl group having 3 or less carbon atoms is preferable, and a methyl group is more preferable. As Xa ₁ , a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group is preferable.

Examples of the divalent linking group of T include an alkylene group, an aromatic ring group, an -COO-Rt- group, and an -O-Rt- group. In the formula, Rt represents an alkylene group or a cycloalkylene group.
T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, and is preferably a -CH _2- group,- (CH ₂ ) _2- group, or- (CH ₂ ) _3- group. Is more preferable.

As the alkyl group of Rx ₁ to Rx ₃ , an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group is preferable. ..
Examples of the cycloalkyl group of Rx ₁ to Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Cycloalkyl group is preferred.
As the aryl group of Rx ₁ to Rx _3, an aryl group having 6 to 10 carbon atoms is preferable, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
As the alkenyl group of Rx ₁ to Rx ₃ , a vinyl group is preferable.
As the cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ , a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group is preferable, and in addition, a norbornyl group, a tetracyclodecanyl group, and the like. Polycyclic cycloalkyl groups such as a tetracyclododecanyl group and an adamantyl group are preferred. Of these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is preferable.
The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is, for example, a group in which one of the methylene groups constituting the ring has a hetero atom such as an oxygen atom, a hetero atom such as a carbonyl group, or vinylidene. It may be replaced by a base. Further, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
As the repeating unit represented by the general formula (AI), for example, it is preferable that Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to form the above-mentioned cycloalkyl group.

When each of the above groups has a substituent, the substituents 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 (1 to 4 carbon atoms). Examples thereof include 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.

The repeating unit represented by the general formula (AI) is preferably an acid-decomposable (meth) acrylic acid tertiary alkyl ester-based repeating unit (Xa ₁ represents a hydrogen atom or a methyl group, and T is a single bond. It is a repeating unit that represents.

The content of the repeating unit having an acid-degradable group is preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 30 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 80 mol% or less, more preferably 70 mol% or less, and particularly preferably 60 mol% or less.

Specific examples of the repeating unit having an acid-degradable group are shown below, but the present invention is not limited thereto. In the formula, Xa ₁ represents any of H, CH ₃ , CF ₃ , and CH ₂ OH, and Rxa and Rxb represent linear or branched alkyl groups having 1 to 5 carbon atoms, respectively.

The resin (A) may contain a repeating unit other than the repeating unit described above.
For example, the resin (A) contains at least one repeating unit selected from the group consisting of the following groups A and / or at least one repeating unit selected from the group consisting of the following groups B. May be good.
Group A: A group consisting of the following repeating units (20) to (29).
(20) Repeating unit having an acid group described later (21) Repeating unit having a fluorine atom or iodine atom described later (22) Repeating unit having a lactone group, sulton group or carbonate group described later (23) The repeating unit having a photoacid generating group (24), which will be described later, is represented by the general formula (V-1) or the following general formula (V-2), and the repeating unit (25), which will be described later, is represented by the formula (A). The repeating unit (26) described later, the repeating unit represented by the formula (B) (27) described later, the repeating unit represented by the formula (C) (28) represented by the formula (D) described later. Repeating unit (29) The repeating unit B group represented by the formula (E), which will be described later: A group consisting of the following repeating units (30) to (32).
(30) A repeating unit having at least one group selected from a lactone group, a sulton group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group, which will be described later. (31) The alicyclic hydrocarbon structure described later. , Repetitive unit showing no acid decomposition property (32) A repeating unit represented by the general formula (III), which has neither a hydroxyl group nor a cyano group, which will be described later.

When the specific resist composition is used as a resist composition for EUV, the resin (A) preferably has at least one repeating unit selected from the group consisting of the above group A.
When the specific resist composition is used as a resist composition for EUV, the resin (A) preferably contains at least one of a fluorine atom and an iodine atom. When the resin (A) contains both a fluorine atom and an iodine atom, the resin (A) may have one repeating unit containing both a fluorine atom and an iodine atom, and the resin (A) may have one repeating unit. It may contain two kinds of a repeating unit having a fluorine atom and a repeating unit containing an iodine atom.
Further, when the specific resist composition is used as a resist composition for EUV, it is also preferable that the resin (A) has a repeating unit having an aromatic group.
When the specific resist composition is used as the resist composition for ArF, the resin (A) preferably has at least one repeating unit selected from the group consisting of the above group B.
When the specific resist composition is used as the resist composition for ArF, it is preferable that the resin (A) does not contain either a fluorine atom or a silicon atom.
Further, when the specific resist composition is used as the resist composition for ArF, it is preferable that the resin (A) does not have an aromatic group.

≪Repeating unit with acid group≫
The resin (A) may have a repeating unit having an acid group.
As the acid group, an acid group having a pKa of 13 or less is preferable.
As the acid group, for example, a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, an isopropanol group and the like are preferable.
Further, in the hexafluoroisopropanol group, one or more (preferably one or two) fluorine atoms may be substituted with a group other than the fluorine atom (alkoxycarbonyl group or the like). -C (CF ₃ ) (OH) -CF _2- thus formed is also preferable as an acid group. Further, one or more of the fluorine atoms may be substituted with a group other than the fluorine atom to form a ring containing −C (CF ₃ ) (OH) −CF _2- .
The repeating unit having an acid group includes a repeating unit having a structure in which a polar group is protected by a leaving group desorbed by the action of the above-mentioned acid, and a repeating unit having a lactone group, a sulton group, or a carbonate group described later. Is preferably a different repeating unit.

The repeating unit having an acid group may have a fluorine atom or an iodine atom.

As the repeating unit having an acid group, the repeating unit represented by the formula (B) is preferable.

R ₃ represents a hydrogen atom or a monovalent organic group which may have a fluorine atom or an iodine atom.
Examples of the fluorine atom or an organic group may monovalent optionally having iodine atom, a group represented by -L ₄ -R ₈ are preferred. L ₄ represents a single bond or an ester group. R ₈ is an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, Alternatively, a group combining these can be mentioned.

R ₄ and R ₅ each independently represent a hydrogen atom, a fluorine atom, an iodine atom, or an alkyl group which may have a fluorine atom or an iodine atom.

L ₂ represents a single bond or an ester group.
L ₃ represents a (n + m + 1) -valent aromatic hydrocarbon ring group or a (n + m + 1) -valent alicyclic hydrocarbon ring group. Examples of the aromatic hydrocarbon ring group include a benzene ring group and a naphthalene ring group. The alicyclic hydrocarbon ring group may be monocyclic or polycyclic, and examples thereof include a cycloalkyl ring group.
R ₆ represents a hydroxyl group or a fluorinated alcohol group (preferably a hexafluoroisopropanol group). When R ₆ is a hydroxyl group, L ₃ is preferably an aromatic hydrocarbon ring group having a (n + m + 1) valence.
R ₇ represents a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
m represents an integer of 1 or more. For m, an integer of 1 to 3 is preferable, and an integer of 1 to 2 is preferable.
n represents an integer of 0 or 1 or more. n is preferably an integer of 1 to 4.
In addition, (n + m + 1) is preferably an integer of 1 to 5.

As the repeating unit having an acid group, a repeating unit represented by the following general formula (I) is also preferable.

In general formula (I),
R ₄₁ , R ₄₂ and R ₄₃ independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. However, R ₄₂ may be bonded to Ar ₄ to form a ring, in which case R ₄₂ represents a single bond or an alkylene group.
X ₄ represents a single bond, -COO-, or -CONR _64- , and R ₆₄ represents a hydrogen atom or an alkyl group.
L ₄ represents a single bond or an alkylene group.
Ar ₄ represents an (n + 1) -valent aromatic ring group, and represents an (n + 2) -valent aromatic ring group when combined with R ₄₂ to form a ring.
n represents an integer from 1 to 5.

The alkyl groups of R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, hexyl group, and 2-ethylhexyl group. , An alkyl group having 20 or less carbon atoms such as an octyl group and a dodecyl group is preferable, an alkyl group having 8 or less carbon atoms is more preferable, and an alkyl group having 3 or less carbon atoms is further preferable.

The cycloalkyl groups of R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) may be monocyclic or polycyclic. Of these, a monocyclic cycloalkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group is preferable.
Examples of the halogen atoms of R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The alkyl group contained in the alkoxycarbonyl group of R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) is preferably the same as the alkyl group in R ₄₁ , R ₄₂ , and R ₄₃ .

Preferred substituents in each of the above groups include, for example, an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, a urethane group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group, a thioether group and an acyl group. , Achilloxy group, alkoxycarbonyl group, cyano group, and nitro group. The substituent preferably has 8 or less carbon atoms.

Ar ₄ represents an (n + 1) -valent aromatic ring group. The divalent aromatic ring group when n is 1, for example, an arylene group having 6 to 18 carbon atoms such as a phenylene group, a trilene group, a naphthylene group, and an anthracenylene group, or a thiophene ring, a furan ring, a pyrrole ring, and the like. A divalent aromatic ring group containing a heterocycle such as a benzothiophene ring, a benzofuran ring, a benzopyrol ring, a triazine ring, an imidazole ring, a benzimidazole ring, a triazole ring, a thiaziazole ring, and a thiazole ring is preferable. The aromatic ring group may have a substituent.

As a specific example of the (n + 1) -valent aromatic ring group when n is an integer of 2 or more, (n-1) arbitrary hydrogen atoms are removed from the above-mentioned specific example of the divalent aromatic ring group. The group that consists of
The (n + 1) -valent aromatic ring group may further have a substituent.

Examples of the substituents that the above-mentioned alkyl group, cycloalkyl group, alkoxycarbonyl group, alkylene group, and (n + 1) -valent aromatic ring group can have include R ₄₁ , R ₄₂ , and R in the general formula (I). _Examples thereof include an alkoxy group such as an alkyl group, a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, and a butoxy group described in ₄₃ ; an aryl group such as a phenyl group; and the like.
_-CONR 64 represented by X ₄ - _{(R 64} represents a hydrogen atom or an alkyl group) The alkyl group for _{R 64} in, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- butyl group, sec Examples thereof include alkyl groups having 20 or less carbon atoms such as a butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a dodecyl group, and an alkyl group having 8 or less carbon atoms is preferable.
As X ₄ , a single bond, -COO-, or -CONH- is preferable, and a single bond, or -COO- is more preferable.

The alkylene group for L _4, a methylene group, an ethylene group, a propylene group, a butylene group, an alkylene group having 1 to 8 carbon atoms such as hexylene, and octylene group.
As Ar ₄ , an aromatic ring group having 6 to 18 carbon atoms is preferable, and a benzene ring group, a naphthalene ring group, and a biphenylene ring group are more preferable.
The repeating unit represented by the general formula (I) preferably has a hydroxystyrene structure. That is, Ar ₄ is preferably a benzene ring group.

As the repeating unit represented by the general formula (I), the repeating unit represented by the following general formula (1) is preferable.

In general formula (1),
A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group.
R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group or an aryloxycarbonyl group, and there are a plurality of them. In some cases, they may be the same or different. When it has a plurality of Rs, they may form a ring jointly with each other. A hydrogen atom is preferable as R.
a represents an integer of 1 to 3.
b represents an integer from 0 to (5-a).

Hereinafter, repeating units having an acid group will be exemplified below. In the formula, a represents 1 or 2.

Among the above repeating units, the repeating units specifically described below are preferable. In the formula, R represents a hydrogen atom or a methyl group, and a represents 2 or 3.

The content of the repeating unit having an acid group is preferably 10 mol% or more, more preferably 15 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less.

≪Repeating unit with fluorine atom or iodine atom≫
The resin (A) may have a repeating unit having a fluorine atom or an iodine atom, in addition to the above-mentioned << repeating unit having an acid-degradable group >> and << repeating unit having an acid group >>. Further, the << repeating unit having a fluorine atom or an iodine atom >> referred to here is a << repeating unit having a lactone group, a sultone group, or a carbonate group >>, << a repeating unit having a photoacid generating group >>, etc., which will be described later. It is preferably different from other types of repeating units belonging to group A.

As the repeating unit having a fluorine atom or an iodine atom, the repeating unit represented by the formula (C) is preferable.

L ₅ represents a single bond or an ester group.
R ₉ represents an alkyl group which may have a hydrogen atom or a fluorine atom or an iodine atom.
R ₁₀ may have an alkyl group which may have a hydrogen atom, a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, a fluorine atom or an iodine atom. Represents an aryl group or a group in which these are combined.

The repeating unit having a fluorine atom or an iodine atom is illustrated below.

The content of the repeating unit having a fluorine atom or an iodine atom is preferably 0 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 50 mol% or less, more preferably 45 mol% or less, still more preferably 40 mol% or less.
As described above, since the repeating unit having a fluorine atom or an iodine atom does not include << repeating unit having an acid-degradable group >> and << repeating unit having an acid group >>, the above-mentioned fluorine atom or iodine The content of the repeating unit having an atom is also intended to be the content of the repeating unit having a fluorine atom or an iodine atom excluding << repeating unit having an acid-degradable group >> and << repeating unit having an acid group >>.

Of the repeating units of the resin (A), the total content of the repeating units containing at least one of a fluorine atom and an iodine atom is preferably 20 mol% or more, preferably 30 mol%, based on all the repeating units of the resin (A). The above is more preferable, and 40 mol% or more is further preferable. The upper limit is not particularly limited, but is, for example, 100 mol% or less.
As the repeating unit containing at least one of a fluorine atom and an iodine atom, for example, a repeating unit having a fluorine atom or an iodine atom and having an acid-degradable group, a fluorine atom or an iodine atom, and Repeating units having an acid group and repeating units having a fluorine atom or an iodine atom can be mentioned.

<< Repeating unit having a lactone group, sultone group, or carbonate group >>
The resin (A) is a repeating unit having at least one selected from the group consisting of a lactone group, a sultone group, and a carbonate group (hereinafter, collectively referred to as "a repeating unit having a lactone group, a sultone group, or a carbonate group". It may also have).
It is also preferable that the repeating unit having a lactone group, a sultone group, or a carbonate group does not have an acid group such as a hexafluoropropanol group.

The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered ring lactone structure or a 5- to 7-membered ring sultone structure. Among them, a 5- to 7-membered ring lactone structure in which another ring structure is fused to form a bicyclo structure or a spiro structure, or a 5- to 7-membered ring sultone in the form of a bicyclo structure or a spiro structure. A structure in which another ring structure is fused is more preferable.
The resin (A) has a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-21), or a table represented by any of the following general formulas (SL1-1) to (SL1-3). It is preferable to have a repeating unit having a lactone group or a sultone group obtained by extracting one or more hydrogen atoms from a ring member atom having a sultone structure.
Further, a lactone group or a sultone group may be directly bonded to the main chain. For example, a ring-membered atom of a lactone group or a sultone group may form the main chain of the resin (A).

The lactone structure or sultone structure portion may have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-degradable group and the like. n2 represents an integer of 0 to 4. When n2 is 2 or more, Rb ₂ existing in plural numbers may be different or may be bonded to form a ring Rb ₂ between the plurality of.

It has a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-21) or a sultone structure represented by any of the general formulas (SL1-1) to (SL1-3). Examples of the repeating unit include a repeating unit represented by the following general formula (AI).

In the general formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Preferred substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom of Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab is a divalent linking group having a single bond, an alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group combining these. Represent. Of these, a single bond or a linking group represented by -Ab _1- CO _2- is preferable. Ab ₁ is a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, and a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornene group is preferable.
V is a group formed by extracting one hydrogen atom from a ring member atom having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-21), or general formulas (SL1-1) to (SL1-1). It represents a group formed by extracting one hydrogen atom from a ring member atom having a sultone structure represented by any of SL1-3).

If an optical isomer is present in the repeating unit having a lactone group or a sultone group, any optical isomer may be used. Further, one kind of optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

As the carbonate group, a cyclic carbonate group is preferable.
As the repeating unit having a cyclic carbonate group, a repeating unit represented by the following general formula (A-1) is preferable.

In the general formula (A-1), _RA ¹ represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group).
n represents an integer greater than or equal to 0.
R _A ² represents a substituent. when n is 2 or more, R _A ² existing in plural, may each be the same or different.
A represents a single bond or a divalent linking group. The divalent linking group includes an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent combination thereof. Group is preferred.
Z represents an atomic group forming a monocyclic or polycyclic ring with a group represented by —O—CO—O— in the formula.

The repeating unit having a lactone group, a sultone group, or a carbonate group is illustrated below.

The content of the repeating unit having a lactone group, a sultone group, or a carbonate group is preferably 1 mol% or more, more preferably 10 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 85 mol% or less, more preferably 80 mol% or less, further preferably 70 mol% or less, and particularly preferably 60 mol% or less.

≪Repeating unit with photoacid generating group≫
The resin (A) may have a repeating unit having a group that generates an acid by irradiation with active light or radiation (hereinafter, also referred to as “photoacid generating group”) as a repeating unit other than the above.
In this case, it can be considered that the repeating unit having this photoacid generating group corresponds to a compound (also referred to as “photoacid generator”) that generates an acid by irradiation with active light or radiation described later.
Examples of such a repeating unit include a repeating unit represented by the following general formula (4).

R ⁴¹ represents a hydrogen atom or a methyl group. L ⁴¹ represents a single bond or a divalent linking group. L ⁴² represents a divalent linking group. R ⁴⁰ represents a structural site that is decomposed by irradiation with active light or radiation to generate an acid in the side chain.

The repeating unit having a photoacid generating group is illustrated below.

In addition, examples of the repeating unit represented by the general formula (4) include the repeating units described in paragraphs [0094] to [0105] of JP-A-2014-041327.

The content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 5 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less.

<< Repeat unit represented by the general formula (V-1) or the following general formula (V-2) >>
The resin (A) may have a repeating unit represented by the following general formula (V-1) or the following general formula (V-2).
The repeating unit represented by the following general formula (V-1) and the following general formula (V-2) is preferably a repeating unit different from the above-mentioned repeating unit.

During the ceremony
R ₆ and R ₇ independently have a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester group (-OCOR or -COOR: R is the number of carbon atoms. 1 to 6 alkyl groups or fluorinated alkyl groups), or carboxyl groups. As the alkyl group, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms is preferable.
n ₃ represents an integer from 0 to 6.
n ₄ represents an integer from 0 to 4.
X ⁴ is a methylene group, an oxygen atom or a sulfur atom.
The repeating unit represented by the general formula (V-1) or (V-2) is illustrated below.

≪Repeating unit to reduce the motility of the main chain≫
The resin (A) preferably has a high glass transition temperature (Tg) from the viewpoint of suppressing excessive diffusion of generated acid or pattern disintegration during development. Tg is preferably greater than 90 ° C, more preferably greater than 100 ° C, even more preferably greater than 110 ° C, and particularly preferably greater than 125 ° C. In addition, since excessively high Tg causes a decrease in the dissolution rate in a developing solution, Tg is preferably 400 ° C. or lower, more preferably 350 ° C. or lower.
In the present specification, the glass transition temperature (Tg) of the polymer such as the resin (A) is calculated by the following method. First, the Tg of a homopolymer composed of only each repeating unit contained in the polymer is calculated by the Bicerano method. Hereinafter, the calculated Tg is referred to as "repeating unit Tg". Next, the mass ratio (%) of each repeating unit to all the repeating units in the polymer is calculated. Next, Tg at each mass ratio is calculated using Fox's formula (described in Materials Letters 62 (2008) 3152, etc.), and the sum of them is used as the Tg (° C.) of the polymer.
The Bicerano method is described in the Precision of developers, Marcel Dekker Inc, New York (1993) and the like. Further, the calculation of Tg by the Bicerano method can be performed using the polymer physical property estimation software MDL Polymer (MDL Information Systems, Inc.).

In order to increase the Tg of the resin (A) (preferably, Tg exceeds 90 ° C.), it is preferable to reduce the motility of the main chain of the resin (A). Examples of the method for reducing the motility of the main chain of the resin (A) include the following methods (a) to (e).
(A) Introduction of a bulky substituent into the main chain (b) Introduction of a plurality of substituents into the main chain (c) Introduction of a substituent that induces an interaction between the resins (A) in the vicinity of the main chain ( d) Main chain formation in a cyclic structure (e) Connection of a cyclic structure to the main chain The resin (A) preferably has a repeating unit in which the Tg of the homopolymer is 130 ° C. or higher.
The type of repeating unit having a homopolymer Tg of 130 ° C. or higher is not particularly limited, and any repeating unit having a homopolymer Tg of 130 ° C. or higher calculated by the Bicerano method may be used. Depending on the type of the functional group in the repeating unit represented by the formulas (A) to (E) described later, the homopolymer corresponds to the repeating unit having a Tg of 130 ° C. or higher.

(Repeating unit represented by the formula (A))
As an example of the specific means for achieving the above (a), there is a method of introducing a repeating unit represented by the formula (A) into the resin (A).

Formulas (A) and _RA represent groups having a polycyclic structure. R _x represents a hydrogen atom, a methyl group, or an ethyl group. The group having a polycyclic structure is a group having a plurality of ring structures, and the plurality of ring structures may or may not be condensed.
Specific examples of the repeating unit represented by the formula (A) include the following repeating units.

In the above formula, R represents a hydrogen atom, a methyl group, or an ethyl group.
Ra is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester group (-OCOR'''. Alternatively, -COOR "": R "" represents an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group), or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by Ra may be replaced with a fluorine atom or an iodine atom.
In addition, R'and R'' are independently alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, alkenyl groups, hydroxyl groups, alkoxy groups, asyloxy groups, cyano groups, nitro groups, amino groups, halogen atoms, respectively. It represents an ester group (-OCOR ″ or −COOR ′ ″: R ″ is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'and R'may be replaced with a fluorine atom or an iodine atom.
L represents a single bond or a divalent linking group. Examples of the divalent linking group include -COO-, -CO-, -O-, -S-, -SO-, -SO _2- , an alkylene group, a cycloalkylene group, an alkenylene group, and a plurality of these. Examples thereof include linked linking groups.
m and n each independently represent an integer of 0 or more. The upper limits of m and n are not particularly limited, but are often 2 or less and more often 1 or less.

(Repeating unit represented by equation (B))
As an example of the specific means for achieving the above (b), there is a method of introducing a repeating unit represented by the formula (B) into the resin (A).

In the formula (B), R _b1 to R _b4 independently represent a hydrogen atom or an organic group, and at least two or more of R _b1 to R _b4 represent an organic group.
Further, when at least one of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, the types of other organic groups are not particularly limited.
Further, when none of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, at least two or more organic groups have three or more constituent atoms excluding hydrogen atoms. It is a substituent.

Specific examples of the repeating unit represented by the formula (B) include the following repeating units.

In the above formula, R independently represents a hydrogen atom or an organic group. Examples of the organic group include organic groups such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, which may have a substituent.
R'is independently an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester group (-OCOR'. 'Or-COOR'': R'represents an alkyl group or fluorinated alkyl group having 1 to 20 carbon atoms) or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'may be replaced with a fluorine atom or an iodine atom.
m represents an integer of 0 or more. The upper limit of m is not particularly limited, but it is often 2 or less, and more often 1 or less.

(Repeating unit represented by formula (C))
As an example of the specific means for achieving the above (c), there is a method of introducing a repeating unit represented by the formula (C) into the resin (A).

In the formula (C), R _c1 to R _c4 independently represent a hydrogen atom or an organic group, and at least one of R _c1 to R _c4 is a hydrogen-bonding hydrogen within 3 atoms from the main chain carbon. It is a group having an atom. Among them, in order to induce the interaction between the main chains of the resin (A), it is preferable to have hydrogen-bonding hydrogen atoms within 2 atoms (closer to the main chain).

Specific examples of the repeating unit represented by the formula (C) include the following repeating units.

In the above formula, R represents an organic group. The organic group may have a substituent, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, and an ester group (-OCOR or -COOR: R is an alkyl group having 1 to 20 carbon atoms. Alternatively, an alkyl fluorinated group) and the like can be mentioned.
R'represents a hydrogen atom or an organic group. Examples of the organic group include organic groups such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. The hydrogen atom in the organic group may be replaced with a fluorine atom or an iodine atom.

(Repeating unit represented by formula (D))
As an example of the specific means for achieving the above (d), there is a method of introducing a repeating unit represented by the formula (D) into the resin (A).

In formula (D), "cylic" represents a group forming a main chain with a cyclic structure. The number of constituent atoms of the ring is not particularly limited.

Specific examples of the repeating unit represented by the formula (D) include the following repeating units.

In the above formula, R is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, respectively. An ester group (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R may be substituted with a fluorine atom or an iodine atom.
In the above formula, R'is independently an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom and an ester group. (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group), or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'may be replaced with a fluorine atom or an iodine atom.
m represents an integer of 0 or more. The upper limit of m is not particularly limited, but it is often 2 or less, and more often 1 or less.

(Repeating unit represented by formula (E))
As an example of the specific means for achieving the above (e), there is a method of introducing a repeating unit represented by the formula (E) into the resin (A).

In formula (E), Re independently represents a hydrogen atom or an organic group. Examples of the organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group and the like, which may have a substituent.
"Cylic" is a cyclic group containing a carbon atom in the main chain. The number of atoms contained in the cyclic group is not particularly limited.

Specific examples of the repeating unit represented by the formula (E) include the following repeating units.

In the above formula, R is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, and a halogen atom. , Esther group (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group), or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R may be substituted with a fluorine atom or an iodine atom.
R'is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester group. (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group), or a carboxyl group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'may be replaced with a fluorine atom or an iodine atom.
m represents an integer of 0 or more. The upper limit of m is not particularly limited, but it is often 2 or less, and more often 1 or less.
Further, in the formula (E-2), the formula (E-4), the formula (E-6), and the formula (E-8), the two Rs may be bonded to each other to form a ring.

The content of the repeating unit represented by the formula (E) is preferably 5 mol% or more, more preferably 10 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 60 mol% or less, more preferably 55 mol% or less.

<< Repeating unit having at least one group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group >>
The resin (A) may have a repeating unit having at least one group selected from a lactone group, a sultone group, a carbonate group, a hydroxyl group, a cyano group, and an alkali-soluble group.
Examples of the repeating unit having a lactone group, a sultone group, or a carbonate group contained in the resin (A) include the repeating unit described in the above-mentioned << Repeating unit having a lactone group, sultone group, or carbonate group >>. The preferable content is also as described in << Repeating unit having a lactone group, sultone group, or carbonate group >> described above.

The resin (A) may have a repeating unit having a hydroxyl group or a cyano group. This improves substrate adhesion and developer affinity.
The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.
The repeating unit having a hydroxyl group or a cyano group preferably does not have an acid-degradable group. Examples of the repeating unit having a hydroxyl group or a cyano group include repeating units represented by the following general formulas (AIIA) to (AIId).

In the general formulas (AIIA) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydrochimethyl group.
R _2c to R _4c independently represent a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _2c to R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _2c to R _4c are hydroxyl groups and the rest are hydrogen atoms. More preferably, two of R _2c to R _4c are hydroxyl groups, and the rest are hydrogen atoms.

The content of the repeating unit having a hydroxyl group or a cyano group is preferably 5 mol% or more, more preferably 10 mol% or more, based on all the repeating units in the resin (A). The upper limit thereof is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less.

Specific examples of the repeating unit having a hydroxyl group or a cyano group are given below, but the present invention is not limited thereto.

The resin (A) may have a repeating unit having an alkali-soluble group.
Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, and an aliphatic alcohol in which the α-position is substituted with an electron-withdrawing group (for example, a hexafluoroisopropanol group). Is preferable. When the resin (A) contains a repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased.
The repeating unit having an alkali-soluble group includes a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit made of acrylic acid and methacrylic acid, or an alkali on the main chain of the resin via a linking group. Repeat units to which soluble groups are attached can be mentioned. The linking group may have a monocyclic or polycyclic cyclic hydrocarbon structure.
As the repeating unit having an alkali-soluble group, a repeating unit made of acrylic acid or methacrylic acid is preferable.

The content of the repeating unit having an alkali-soluble group is preferably 0 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, based on all the repeating units in the resin (A). The upper limit is preferably 20 mol% or less, more preferably 15 mol% or less, still more preferably 10 mol% or less.

Specific examples of repeating units having an alkali-soluble group are shown below, but the present invention is not limited thereto. In the specific example, Rx represents H, CH ₃ , CH ₂ OH or CF ₃ .

As the repeating unit having at least one kind selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group, a repeating unit having at least two selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group is preferable. , A repeating unit having a cyano group and a lactone group is more preferable, and a repeating unit having a structure in which a cyano group is substituted with a lactone structure represented by the general formula (LC1-4) is further preferable.

≪Repeating unit with alicyclic hydrocarbon structure and not showing acid degradability≫
The resin (A) may have an alicyclic hydrocarbon structure and may have a repeating unit that does not exhibit acid degradability. As a result, the elution of low molecular weight components from the resist film to the immersion liquid during immersion exposure can be reduced. Examples of such a repeating unit include a repeating unit derived from 1-adamantyl (meth) acrylate, diamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, cyclohexyl (meth) acrylate and the like.

<< Repeat unit represented by the general formula (III), which has neither a hydroxyl group nor a cyano group >>
The resin (A) may have a repeating unit represented by the general formula (III), which has neither a hydroxyl group nor a cyano group.

In the general formula (III), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group or _-CH 2 -O-Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.

The cyclic structure of R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include a cycloalkyl group having 3 to 12 carbon atoms (more preferably 3 to 7 carbon atoms) and a cycloalkenyl group having 3 to 12 carbon atoms.

Examples of the polycyclic hydrocarbon group include a ring-aggregated hydrocarbon group and a crosslinked cyclic hydrocarbon group. Examples of the crosslinked ring-type hydrocarbon ring include a bicyclic hydrocarbon ring, a three-ring hydrocarbon ring, and a four-ring hydrocarbon ring. The crosslinked cyclic hydrocarbon ring also includes a fused ring in which a plurality of 5- to 8-membered cycloalkane rings are condensed.
As the crosslinked cyclic hydrocarbon group, a norbornyl group, an adamantyl group, a bicyclooctanyl group, or a tricyclo [5, ^2, 1, 0 ^2,6 ] decanyl group is preferable, and a norbonyl group or an adamantyl group is more preferable.

The alicyclic hydrocarbon group may have a substituent, and examples of the substituent include a halogen atom, an alkyl group, a hydroxyl group protected by a protective group, and an amino group protected by a protective group.
As the halogen atom, a bromine atom, a chlorine atom, or a fluorine atom is preferable.
As the alkyl group, a methyl group, an ethyl group, a butyl group, or a t-butyl group is preferable. The alkyl group may further have a substituent, and examples of the substituent include a halogen atom, an alkyl group, a hydroxyl group protected by a protective group, and an amino group protected by a protective group.

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

The content of the repeating unit represented by the general formula (III), which has neither a hydroxyl group nor a cyano group, is preferably 0 to 40 mol%, preferably 0 to 20 mol%, based on all the repeating units in the resin (A). More preferably mol%.
Specific examples of the repeating unit represented by the general formula (III) are given below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , CH ₂ OH, or CF ₃ .

≪Other repeating units≫
Further, the resin (A) may have a repeating unit other than the repeating unit described above.
For example, the resin (A) has a repeating unit selected from the group consisting of a repeating unit having an oxatian ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantin ring group. You may be doing it.
Such repeating units are illustrated below.

In addition to the above-mentioned repeating structural units, the resin (A) has various repeating structural units for the purpose of adjusting dry etching resistance, standard developer suitability, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like. You may be doing it.

As the resin (A), it is also preferable that all the repeating units (particularly when the specific resist composition is used as the resist composition for ArF) are composed of (meth) acrylate-based repeating units. In this case, all the repeating units are methacrylate-based repeating units, all the repeating units are acrylate-based repeating units, and all the repeating units are either methacrylate-based repeating units or acrylate-based repeating units. It can be used, and the acrylate-based repeating unit is preferably 50 mol% or less of all the repeating units.

The resin (A) can be synthesized according to a conventional method (for example, radical polymerization).
The weight average molecular weight of the resin (A) is preferably 3,000 to 20,000, more preferably 5,000 to 15,000 as a polystyrene-equivalent value according to the GPC method. By setting the weight average molecular weight of the resin (A) to 3,000 to 200,000, deterioration of heat resistance and dry etching resistance can be further suppressed. Further, deterioration of developability and deterioration of film forming property due to high viscosity can be further suppressed.
The dispersity (molecular weight distribution) of the resin (A) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.

In the specific resist composition, the content of the resin (A) is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass, based on the total solid content of the composition.
The solid content is intended to be a component in the composition excluding the solvent, and any component other than the solvent is regarded as a solid content even if it is a liquid component.
Further, the resin (A) may be used alone or in combination of two or more.

<Acid diffusion control agent>
The specific resist composition may further contain an acid diffusion control agent.
The acid diffusion control agent acts as a quencher that traps the acid generated from the photoacid generator or the like at the time of exposure and suppresses the reaction of the acid-degradable resin in the unexposed portion due to the excess generated acid. The acid diffusion control agent includes, for example, a basic compound (DA), a basic compound (DB) whose basicity is reduced or eliminated by irradiation with active light or radiation, and a nitrogen atom, which is eliminated by the action of an acid. A low molecular weight compound (DD) having a group, an onium salt compound (DE) having a nitrogen atom in the cation portion, and the like can be used as an acid diffusion control agent. In the specific resist composition, a known acid diffusion control agent can be appropriately used. For example, paragraphs [0627] to [0664] of U.S. Patent Application Publication No. 2016/0070167A1, paragraphs [0995] to [0187] of U.S. Patent Application Publication No. 2015/0004544A1, U.S. Patent Application Publication No. 2016/0237190A1. Known compounds disclosed in paragraphs [0403] to [0423] of the specification and paragraphs [0259] to [0328] of US Patent Application Publication No. 2016/0274458A1 can be suitably used as the acid diffusion control agent.

(Basic compound (DA))
As the basic compound (DA), compounds having a structure represented by the following formulas (A) to (E) are preferable.

In the general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and each independently has a hydrogen atom, an alkyl group (preferably 1 to 20 carbon atoms), a cycloalkyl group (preferably 3 to 20 carbon atoms) or an aryl. Represents a group (6 to 20 carbon atoms). R ²⁰¹ and R ²⁰² may be combined with each other to form a ring.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different, and each independently represents an alkyl group having 1 to 20 carbon atoms.

The alkyl groups in the general formulas (A) and (E) may have a substituent or may be unsubstituted.
Regarding the above alkyl group, as the alkyl group having a substituent, 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 is preferable.
It is more preferable that the alkyl groups in the general formulas (A) and (E) are unsubstituted.

As the basic compound (DA), guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholin, aminoalkylmorpholin, or piperidine are preferable, and imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, and tri. A compound having an alkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, or an aniline derivative having a hydroxyl group and / or an ether bond is more preferable.

(Basic compound (DB) whose basicity is reduced or eliminated by irradiation with active light or radiation)
A basic compound (DB) whose basicity is reduced or eliminated by irradiation with active light or radiation (hereinafter, also referred to as “compound (DB)”) has a proton acceptor functional group and is active light or radiation. It is a compound whose proton acceptor property is reduced or eliminated, or changes from proton acceptor property to acidity by being decomposed by irradiation with.

A proton-accepting functional group is a functional group having a group or an electron capable of electrostatically interacting with a proton, 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 shown in the following formula.

Preferred partial structures of the proton acceptor functional group include, for example, a crown ether structure, an aza crown ether structure, a primary to tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure.

The compound (DB) is decomposed by irradiation with active light or radiation to reduce or eliminate the proton acceptor property, or generate a compound in which the proton acceptor property is changed to acidic. Here, the decrease or disappearance of the proton acceptor property, or the change from the proton acceptor property to the acidity is a change in the proton acceptor property due to the addition of a proton to the proton acceptor property functional group, and is specific. Means that when a proton adduct is formed from a compound (DB) having a proton-accepting functional group and a proton, the equilibrium constant in its chemical equilibrium decreases.
Proton acceptability can be confirmed by measuring pH.

The acid dissociation constant (pKa) of the compound generated by decomposing the compound (DB) by irradiation with active light or radiation preferably satisfies pKa <-1, and more preferably -13 <pKa <-1. , -13 <pKa <-3 is more preferable.

The acid dissociation constant (pKa) can be obtained by the method described above.

(Low molecular weight compound (DD) having a nitrogen atom and having a group eliminated by the action of an acid)
A low molecular weight compound (DD) having a nitrogen atom and having a group desorbed by the action of an acid (hereinafter, also referred to as “compound (DD)”) has a group desorbed by the action of an acid on the nitrogen atom. It is preferably an amine derivative.
As the group desorbed by the action of the acid, an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a hemiaminol ether group is preferable, and a carbamate group or a hemiaminol ether group is more preferable. ..
The molecular weight of the compound (DD) is preferably 100 to 1000, more preferably 100 to 700, and even more preferably 100 to 500.
Compound (DD) may have a carbamate group having a protecting group on the nitrogen atom. The protecting group constituting the carbamate group is represented by the following general formula (d-1).

In the general formula (d-1)
R _b is independently a hydrogen atom, an alkyl group (preferably 1 to 10 carbon atoms), a cycloalkyl group (preferably 3 to 30 carbon atoms), an aryl group (preferably 3 to 30 carbon atoms), and an alkoxy group. It represents (preferably 1 to 10 carbon atoms) or an alkoxyalkyl group (preferably 1 to 10 carbon atoms). R _b may be connected to each other to form a ring.
The alkyl group, cycloalkyl group, aryl group, and aralkyl group represented by _Rb are independently functional groups such as hydroxyl groups, cyano groups, amino groups, pyrrolidino groups, piperidino groups, morpholino groups, and oxo groups, and alkoxy groups. Alternatively, it may be substituted with a halogen atom. The same applies to the alkoxyalkyl group indicated by R _b .

As R _b , a linear or branched alkyl group, a cycloalkyl group, or an aryl group is preferable, and a linear or branched alkyl group or a cycloalkyl group is more preferable.
Examples of the ring formed by connecting the two R _bs to each other include an alicyclic hydrocarbon, an aromatic hydrocarbon, a heterocyclic hydrocarbon, and a derivative thereof.
Specific structures of the group represented by the general formula (d-1) include, but are not limited to, the structure disclosed in paragraph [0466] of US Patent Publication US2012 / 0135348A1.

The compound (DD) is preferably a compound represented by the following general formula (6).

In the general formula (6)
l represents an integer of 0 to 2, m represents an integer of 1 to 3, and satisfies l + m = 3.
_Ra represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. When l is 2, the two _Ras may be the same or different, and the two _Ras may be interconnected to form a heterocycle with the nitrogen atom in the equation. This heterocycle may contain a heteroatom other than the nitrogen atom in the formula.
R _b has the same meaning as _{R b} in formula (d-1), and preferred examples are also the same.
In the general formula (6), the alkyl group as R _a, a cycloalkyl group, an aryl group and aralkyl group, each independently, alkyl group as R _b, cycloalkyl, aryl and aralkyl groups, is replaced The group may be substituted with a group similar to the group described above.

Specific examples of the alkyl group, cycloalkyl group, aryl group, and aralkyl group of _Ra (these groups may be substituted with the above groups) are the same groups as those described above for R _b. Can be mentioned.
Specific examples of a particularly preferred compound (DD) in the present invention include, but are not limited to, the compounds disclosed in paragraph [0475] of U.S. Patent Application Publication No. 2012/01335348A1.

(Onium salt compound (DE) having a nitrogen atom in the cation part)
The onium salt compound (DE) having a nitrogen atom in the cation portion (hereinafter, also referred to as “compound (DE)”) is preferably a compound having a basic moiety containing a nitrogen atom in the cation portion. The basic moiety is preferably an amino group, more preferably an aliphatic amino group. It is more preferable that all the atoms adjacent to the nitrogen atom in the basic moiety are hydrogen atoms or carbon atoms. Further, from the viewpoint of improving basicity, it is preferable that an electron-attracting functional group (carbonyl group, sulfonyl group, cyano group, halogen atom, etc.) is not directly bonded to the nitrogen atom.
Preferred specific examples of compound (DE) include, but are not limited to, the compound disclosed in paragraph [0203] of US Patent Application Publication 2015/0309408A1.

A preferable example of the acid diffusion control agent is shown below.

When the specific resist composition contains an acid diffusion control agent, the content of the acid diffusion control agent (the total of multiple types, if present) is 0.1 to 11.0 with respect to the total solid content of the composition. The mass% is preferable, 0.1 to 10.0 mass% is more preferable, 0.1 to 8.0 mass% is further preferable, and 0.1 to 5.0 mass% is particularly preferable.
In the specific resist composition, one type of acid diffusion control agent may be used alone, or two or more types may be used in combination.

<Hydrophobic resin>
The specific resist composition may contain a hydrophobic resin different from the resin (A) in addition to the resin (A).
Hydrophobic resins are preferably designed to be unevenly distributed on the surface of the resist film, but unlike surfactants, they do not necessarily have to have hydrophilic groups in the molecule, and polar and non-polar substances are uniformly mixed. It does not have to contribute to doing so.
The effects of adding the hydrophobic resin include controlling the static and dynamic contact angles of the resist film surface with respect to water, and suppressing outgas.

Hydrophobic resin from the viewpoint of uneven distribution in the film surface layer, "fluorine atom", "silicon atom", and to have any one or more "CH ₃ partial structure contained in the side chain portion of the resin" Is preferable, and it is more preferable to have two or more kinds. Further, the hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be contained in the main chain of the resin or may be substituted in the side chain.

When the hydrophobic resin contains fluorine atoms and / or silicon atoms, the fluorine atoms and / or silicon atoms in the hydrophobic resin may be contained in the main chain of the resin and may be contained in the side chains. You may.

When the hydrophobic resin contains a fluorine atom, the partial structure having a fluorine atom is preferably an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom.
The alkyl group having a fluorine atom (preferably 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. Further, it may have a substituent other than a fluorine atom.
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 a substituent other than the fluorine atom.
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 and a naphthyl group is substituted with a fluorine atom, and even if the aryl group has a substituent other than the fluorine atom. Good.
Examples of repeating units having a fluorine atom or a silicon atom include those exemplified in paragraph [0519] of US2012 / 0251948A1.

Further, as described above, the hydrophobic resin may also preferably comprise a CH ₃ partial structure side chain moiety.
Here, CH ₃ partial structure contained in the side chain portion in the hydrophobic resin are those containing CH ₃ partial structure ethyl, and propyl groups and the like have.
On the other hand, the methyl group directly bonded to the main chain of the hydrophobic resin (for example, the α-methyl group of the repeating unit having a methacrylic acid structure) contributes to the uneven distribution of the surface of the hydrophobic resin due to the influence of the main chain. small order shall not be included in the CH ₃ partial structures in the present invention.

Regarding the hydrophobic resin, the description in paragraphs [0348] to [0415] of JP2014-010245A can be referred to, and these contents are incorporated in the present specification.

As the hydrophobic resin, the resins described in JP-A-2011-24801, JP-A-2010-175859, and JP-A-2012-032544 can also be preferably used.

A preferable example of the monomer corresponding to the repeating unit constituting the hydrophobic resin is shown below.

When the specific resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0% by mass, preferably 0.1 to 15.0% by mass, based on the total solid content of the composition. % Is more preferable, 0.1 to 10.0% by mass is further preferable, and 0.1 to 6.0% by mass is particularly preferable.

<Surfactant>
The specific resist composition may contain a surfactant. By containing a surfactant, it is possible to form a pattern having better adhesion and fewer development defects.
As the surfactant, a fluorine-based surfactant and / or a silicon-based surfactant is preferable.
Fluorine-based and / or silicon-based surfactants include, for example, the surfactants described in paragraph [0276] of US Patent Application Publication No. 2008/0248425. In addition, Ftop EF301 or EF303 (manufactured by Shin-Akita Kasei Co., Ltd.); Florard FC430, 431 or 4430 (manufactured by Sumitomo 3M Co., Ltd.); Megafuck F171, F173, F176, F189, F113, F110, F177, F120 or R08 (manufactured by DIC Co., Ltd.); Surflon S-382, SC101, 102, 103, 104, 105 or 106 (manufactured by Asahi Glass Co., Ltd.); Troysol S-366 (manufactured by Troy Chemical Co., Ltd.); GF-300 or GF-150 (manufactured by Toa Synthetic Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.); EFTOP EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802 or EF601 ( Gemco Co., Ltd.); PF636, PF656, PF6320 or PF6520 (manufactured by OMNOVA); KH-20 (manufactured by Asahi Kasei Co., Ltd.); FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D or 222D (Manufactured by Neos Co., Ltd.) may be used. The polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

Further, the surfactant is a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method) in addition to the known surfactants as shown above. May be synthesized using. Specifically, a polymer having a fluoroaliphatic group derived from this fluoroaliphatic compound may be used as a surfactant. This fluoroaliphatic compound can be synthesized, for example, by the method described in JP-A-2002-090991.
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 the polymer is irregularly distributed. It may be a block copolymerized product. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, and a poly (oxybutylene) group, and poly (oxyethylene, oxypropylene, and oxyethylene). It may be a unit having alkylenes having different chain lengths within the same chain length, such as block conjugate) or poly (block conjugate of oxyethylene and oxypropylene). Further, the copolymer of the monomer having a fluoroaliphatic group and the (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer, but also a monomer having two or more different fluoroaliphatic groups. A ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates) or the like may be used.
For example, as commercially available surfactants, Megafac F178, F-470, F- 473, F-475, F-476, F-472 ( manufactured by DIC _(Ltd.)), acrylates having a C _{6 F 13} group ( or methacrylate) and (poly (oxyalkylene)) acrylate (copolymer of or methacrylate), acrylate having a C ₃ F ₇ group (or methacrylate) (poly (oxyethylene) and) acrylate (or methacrylate) (poly (Oxypropylene)) Examples thereof include a copolymer with acrylate (or methacrylate).
In addition, surfactants other than the fluorine-based and / or silicon-based surfactants described in paragraph [0280] of US Patent Application Publication No. 2008/0248425 may be used.

These surfactants may be used alone or in combination of two or more.
The content of the surfactant is preferably 0.0001 to 2.0% by mass, more preferably 0.0005 to 1.0% by mass, based on the total solid content of the composition.

<Solvent>
The specific resist composition contains a solvent.
Solvents include (M1) propylene glycol monoalkyl ether carboxylate, and (M2) propylene glycol monoalkyl ether, lactic acid ester, acetate, butyl butyrate, alkoxypropionic acid ester, chain ketone, cyclic ketone, lactone, and alkylene. It preferably contains at least one selected from the group consisting of carbonates. The solvent may further contain components other than the components (M1) and (M2).

The present inventors have found that when such a solvent is used in combination with the above-mentioned resin (A), the coatability of the composition is improved and a pattern having a small number of development defects can be formed. .. The reason is not always clear, but since these solvents have a good balance of solubility, boiling point and viscosity of the resin (A) described above, uneven film thickness of the composition film and generation of precipitates in spin coating, etc. The present inventors believe that this is due to the ability to suppress.

As the component (M1), one or more selected from the group consisting of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate is preferable, and propylene glycol monomethyl ether acetate (Ppropylene glycol monomethyl ether acetate). PGMEA) is more preferred.

The components (M2) are preferably as follows.
As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) or propylene glycol monoethyl ether (PGEE) is preferable.
As the lactate ester, ethyl lactate, butyl lactate, or propyl lactate is preferable.
As the acetic acid ester, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl acetate, butyl formate, propyl formate, or 3-methoxybutyl acetate are preferable.
As the alkoxypropionic acid ester, methyl 3-methoxypropionate (MMP: methyl 3-methoxypropionate) or ethyl 3-ethoxypropionate (EEP: ethyl 3-ethoxypropionate) is preferable.
Chain ketones include 1-octanone, 2-octanone, 1-nonanonone, 2-nonanonone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl. Ketones, acetylacetones, acetonylacetones, ionones, diacetonyl alcohols, acetylcarbinol, acetophenones, methylnaphthyl ketones, or methylamyl ketones are preferred.
As the cyclic ketone, methylcyclohexanone, isophorone, or cyclohexanone is preferable.
As the lactone, γ-butyrolactone is preferable.
As the alkylene carbonate, propylene carbonate is preferable.

As the component (M2), propylene glycol monomethyl ether (PGME), ethyl lactate, ethyl 3-ethoxypropionate, methylamyl ketone, cyclohexanone, butyl acetate, pentyl acetate, γ-butyrolactone, or propylene carbonate is preferable.

In addition to the above components, it is preferable to use an ester solvent having 7 or more carbon atoms (preferably 7 to 14, more preferably 7 to 12 and even more preferably 7 to 10) and having a heteroatom number of 2 or less.

Ester-based solvents having 7 or more carbon atoms and 2 or less heteroatomic atoms include amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, butyl propionate, and isobutyl isobutyrate. , Heptyl propionate, or butyl butate is preferred, and isoamyl acetate is more preferred.

The component (M2) preferably has a flash point (hereinafter, also referred to as fp) of 37 ° C. or higher. Examples of such a component (M2) include propylene glycol monomethyl ether (fp: 47 ° C.), ethyl lactate (fp: 53 ° C.), ethyl 3-ethoxypropionate (fp: 49 ° C.), and methylamyl ketone (fp: 42 ° C.). ℃), cyclohexanone (fp: 44 ° C), pentyl acetate (fp: 45 ° C), methyl 2-hydroxyisobutyrate (fp: 45 ° C), γ-butyrolactone (fp: 101 ° C), or propylene carbonate (fp: 132 ° C). ℃) is preferable. Of these, propylene glycol monoethyl ether, ethyl lactate, pentyl acetate, or cyclohexanone is more preferable, and propylene glycol monoethyl ether or ethyl lactate is even more preferable.
Here, the "flash point" means a value described in the reagent catalog of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Co., Ltd.

The mass ratio (M1 / M2) of the mixture of the component (M1) and the component (M2) in the mixed solvent is preferably in the range of "100/0" to "15/85", and is preferably "100/0". More preferably, it is in the range of "40/60". By adopting such a configuration, it is possible to further reduce the number of development defects.

As described above, the solvent may further contain components other than the components (M1) and (M2). In this case, the content of the components other than the components (M1) and (M2) is preferably in the range of 30% by mass or less and more preferably in the range of 5 to 30% by mass with respect to the total amount of the solvent.

The content of the solvent in the specific resist composition is preferably set so that the solid content concentration is 0.5 to 30.0% by mass, and is set to 1.0 to 20.0% by mass. More preferred. In this way, the applicability of the specific resist composition is more excellent.

<Other additives>
The specific resist composition further contains a resin other than those described above, a cross-linking agent, an acid growth agent, a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, a dissolution inhibitor, a dissolution accelerator and the like. You may be.

[Pattern formation method]
The pattern forming method of the present invention includes the following steps 1 to 4.
Step 1: Purify the resist composition by the purification method of the present invention Step 2: Form a resist film on the support (on the substrate) using the purified resist composition Step 3: Expose the resist film Step 4: Step of developing the exposed resist film using a developing solution to form a pattern The procedure of each of the above steps will be described in detail below.

[Step 1; Purification step]
The purification method of the present invention is as described above.
Further, as the resist composition, a resist composition can be used. The specific resist composition is as described above.

<Other purification treatment, storage of resist composition>
In the resist composition used in the pattern forming method of the present invention, it is preferable that the content of metal atoms is reduced. Specific methods for reducing the content of metal atoms in the resist composition include a method of selecting a raw material having a low metal content as a raw material constituting various materials in the resist composition, and various materials in the composition. Examples thereof include a method of filtering the constituent raw materials with a filter, and a method of distilling under conditions in which contamination is suppressed as much as possible by lining the inside of the apparatus with Teflon (registered trademark).

Further, as a method for reducing the content of metal atoms in the composition, there is also a method of removing the resist composition with an adsorbent. As the adsorbent, a known adsorbent can be used. For example, an inorganic adsorbent such as silica gel and zeolite, and an organic adsorbent such as activated carbon can be used.
Further, in order to reduce the content of metal atoms in the composition, it is necessary to prevent the mixing of metal impurities in the manufacturing process. Whether or not the metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of the metal components contained in the cleaning liquid used for cleaning the manufacturing equipment.

It is preferable that the inside of the resist composition manufacturing apparatus is gas-replaced with an inert gas such as nitrogen. Thereby, it is possible to suppress the dissolution of the active gas such as oxygen in the composition. The specific resist composition undergoes various purifications and then is filled in a clean container. The composition filled in the container is preferably stored refrigerated. As a result, performance deterioration over time is suppressed. The shorter the time from the completion of filling the composition into the container to the start of refrigerated storage, the more preferably, generally within 24 hours, preferably within 16 hours, more preferably within 12 hours, and 10 Within hours is even more preferred. The storage temperature is preferably 0 to 15 ° C, more preferably 0 to 10 ° C, and even more preferably 0 to 5 ° C.

[Step 2: Resist film forming step]
Step 2 is a step of forming a resist film on the support (on the substrate) using the purified resist composition.

Next, a method of forming a resist film on the substrate using the resist composition will be described.
Examples of the method of forming a resist film on a substrate using the resist composition include a method of applying the resist composition on the substrate.

The resist composition can be applied onto a substrate (eg, silicon, silicon dioxide coating) such as that used in the manufacture of integrated circuit elements by an appropriate coating method such as a spinner or coater. As a coating method, spin coating using a spinner is preferable. The rotation speed at the time of spin coating using a spinner is preferably 1000 to 3000 rpm.
After applying the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoat films (inorganic film, organic film, antireflection film) may be formed under the resist film.

Examples of the drying method include a method of heating and drying. The heating can be performed by a means provided in a normal exposure machine and / or a developing machine, and may be performed by using a hot plate or the like. The heating temperature is preferably 80 to 150 ° C, more preferably 80 to 140 ° C, and even more preferably 80 to 130 ° C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, still more preferably 60 to 600 seconds.

The film thickness of the resist film is not particularly limited, but 10 to 150 nm is preferable, and 15 to 100 nm is more preferable, from the viewpoint of forming a fine pattern with higher accuracy.

A top coat may be formed on the upper layer of the resist film by using the top coat composition.
It is preferable that the topcoat composition is not mixed with the resist film and can be uniformly applied to the upper layer of the resist film.
Further, it is preferable to dry the resist film before forming the top coat. Next, the topcoat composition can be formed on the obtained resist film by applying the topcoat composition on the obtained resist film by the same means as the method for forming the resist film and further drying.
The film thickness of the top coat is preferably 10 to 200 nm, more preferably 20 to 100 nm.
The topcoat composition contains, for example, a resin, an additive and a solvent.
As the resin, the same resin as the hydrophobic resin described above can be used. The content of the resin is preferably 50 to 99.9% by mass, more preferably 60 to 99.7% by mass, based on the total solid content of the topcoat composition.
As the additive, the acid diffusion control agent described above can be used. Further, a compound having a radical trap group such as a compound having an N-oxyl-free radical group can also be used. Examples of such a compound include [4- (benzoyloxy) -2,2,6,6-tetramethylpiperidinooxy] radicals. The content of the additive is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the topcoat composition.
The solvent preferably does not dissolve the resist film, for example, an alcohol solvent (4-methyl-2-pentanol, etc.), an ether solvent (diisoamyl ether, etc.), an ester solvent, a fluorine solvent, and a hydrocarbon. Examples thereof include hydrogen-based solvents (n-decane and the like).
The content of the solvent in the topcoat composition is preferably set so that the solid content concentration is 0.5 to 30% by mass, and more preferably 1 to 20% by mass.
In addition, the top coat composition may contain a surfactant in addition to the above-mentioned additives, and as the above-mentioned surfactant, a surfactant which may be contained in the composition of the present invention can be used. The content of the surfactant is preferably 0.0001 to 2% by mass, more preferably 0.0005 to 1% by mass, based on the total solid content of the topcoat composition.
In addition, the top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, based on the description in paragraphs [0072] to [0082] of JP-A-2014-059543. Can form a top coat.
For example, it is preferable to form a top coat containing a basic compound as described in JP2013-61648A on the resist film. Specific examples of basic compounds that can be contained in the top coat include basic compounds that may be contained in the composition of the present invention.
Further, the top coat preferably contains 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.

[Step 3: Exposure step]
Step 3 is a step of exposing the resist film.
Examples of the exposure method include a method of irradiating the formed resist film with active light rays or radiation through a predetermined mask.
Examples of the active light or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-ray, and electron beam, preferably 250 nm or less, more preferably 220 nm or less, and particularly preferably 1. far ultraviolet light at a wavelength of ~ 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), _{F 2} excimer laser (157nm), EUV (13nm) , X -ray, and electron beam and the like ..

It is preferable to bake (heat) after exposure and before developing. Baking accelerates the reaction of the exposed area, resulting in better sensitivity and pattern shape.
The heating temperature is preferably 80 to 150 ° C, more preferably 80 to 140 ° C, and even more preferably 80 to 130 ° C.
The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, still more preferably 30 to 120 seconds.
The heating can be performed by a means provided in a normal exposure machine and / or a developing machine, and may be performed by using a hot plate or the like.
This process is also called post-exposure baking.

[Step 4: Development step]
Step 4 is a step of developing the exposed resist film using a developing solution to form a pattern.

As a developing method, a method of immersing the substrate in a tank filled with a developing solution for a certain period of time (dip method), and a method of raising the developing solution on the surface of the substrate by surface tension and allowing it to stand still for a certain period of time (paddle method). , A method of spraying the developer on the surface of the substrate (spray method), and a method of continuing to eject the developer while scanning the developer discharge nozzle at a constant speed on the substrate rotating at a constant speed (dynamic discharge method). Can be mentioned.
Further, after the step of performing the development, a step of stopping the development may be carried out while substituting with another solvent.
The development time is not particularly limited as long as the resin in the unexposed portion is sufficiently dissolved, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds.
The temperature of the developing solution is preferably 0 to 50 ° C, more preferably 15 to 35 ° C.

Examples of the developing solution include an alkaline developing solution and an organic solvent developing solution.
As the alkaline developer, it is preferable to use an alkaline aqueous solution containing an alkali. The type of alkaline aqueous solution is not particularly limited, and includes, for example, a quaternary ammonium salt typified by tetramethylammonium hydroxide, an inorganic alkali, a primary amine, a secondary amine, a tertiary amine, an alcohol amine, a cyclic amine, and the like. An alkaline aqueous solution can be mentioned. Among them, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt typified by tetramethylammonium hydroxide (TMAH). An appropriate amount of alcohols, surfactants and the like may be added to the alkaline developer. The alkali concentration of the alkaline developer is usually 0.1 to 20% by mass. The pH of the alkaline developer is usually 10.0 to 15.0.

The organic solvent developer is a developer containing an organic solvent.
The vapor pressure of the organic solvent contained in the organic solvent developer (in the case of a mixed solvent, the vapor pressure as a whole) is preferably 5 kPa or less, more preferably 3 kPa or less, and further preferably 2 kPa or less at 20 ° C. By reducing the vapor pressure of the organic solvent to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, the temperature uniformity in the wafer surface is improved, and as a result, the dimensional uniformity in the wafer surface is improved. Improve.

Examples of the organic solvent used in the organic solvent developing solution include known organic solvents, and examples thereof include ester-based solvents, ketone-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

The organic solvent contained in the organic solvent developing solution has 7 or more carbon atoms (preferably 7 to 14 and 7 to 14) from the viewpoint that swelling of the resist film can be suppressed when EUV and an electron beam are used in the exposure step. 12 is more preferable, and 7 to 10 is more preferable), and it is preferable to use an ester solvent having a heteroatom number of 2 or less.

The hetero atom of the ester-based solvent is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, and a sulfur atom. The number of heteroatoms is preferably 2 or less.

Ester-based solvents having 7 or more carbon atoms and 2 or less heteroatomic atoms include amyl acetate, isoamyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, and butyl propionate. , Isobutyl isobutyrate, heptyl propionate, butyl butane and the like are preferred, and isoamyl acetate is more preferred.

When using EUV and an electron beam in the exposure step, the organic solvent contained in the organic solvent developing solution is replaced with the ester solvent and the ester solvent having 7 or more carbon atoms and 2 or less hetero atoms. A mixed solvent of the above-mentioned hydrocarbon solvent or the above-mentioned ketone solvent and the above-mentioned hydrocarbon solvent may be used. Even in this case, it is effective in suppressing the swelling of the resist film.

When an ester solvent and a hydrocarbon solvent are used in combination, it is preferable to use isoamyl acetate as the ester solvent. Further, as the hydrocarbon solvent, a saturated hydrocarbon solvent (for example, octane, nonane, decane, dodecane, undecane, hexadecane, etc.) is preferable from the viewpoint of adjusting the solubility of the resist film.

When a ketone solvent and a hydrocarbon solvent are used in combination, it is preferable to use 2-heptanone as the ketone solvent. Further, as the hydrocarbon solvent, a saturated hydrocarbon solvent (for example, octane, nonane, decane, dodecane, undecane, hexadecane, etc.) is preferable from the viewpoint of adjusting the solubility of the resist film.

When the above mixed solvent is used, the content of the hydrocarbon solvent depends on the solvent solubility of the resist membrane, and is not particularly limited, and the required amount may be determined as appropriate.

A plurality of the above organic solvents may be mixed, or may be mixed with a solvent other than the above or water and used. However, in order to fully exert the effect of the present invention, the water content of the developing solution as a whole is preferably less than 10% by mass, and more preferably substantially no water is contained. The concentration of the organic solvent (total in the case of a plurality of mixture) in the developing solution is preferably 50% by mass or more, more preferably 50 to 100% by mass, further preferably 85 to 100% by mass, and particularly preferably 90 to 100% by mass. , 95-100% by mass is most preferable.

[Other processes]
The pattern forming method preferably includes a step of washing with a rinsing solution after the step 4.
Examples of the rinsing solution used in the rinsing step after the step of developing with the developing solution include pure water. An appropriate amount of surfactant may be added to pure water.
An appropriate amount of surfactant may be added to the rinse solution.

The method of the rinsing process is not particularly limited, but for example, a method of continuously discharging the rinsing liquid onto a substrate rotating at a constant speed (rotary coating method), or immersing the substrate in a tank filled with the rinsing liquid for a certain period of time. Examples thereof include a method (dip method) and a method of spraying a rinse liquid on the substrate surface (spray method).
In addition, the pattern forming method of the present invention may include a heating step (Post Bake) after the rinsing step. In this step, the developer and rinse liquid remaining between the patterns and inside the patterns are removed by baking. In addition, this step has the effect of smoothing the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is usually performed at 40 to 250 ° C. (preferably 90 to 200 ° C.) for 10 seconds to 3 minutes (preferably 30 to 120 seconds).

Further, the substrate may be etched using the formed pattern as a mask. That is, the pattern formed in step 4 may be used as a mask to process the substrate (or the underlayer film and the substrate) to form the pattern on the substrate.
The processing method of the substrate (or the underlayer film and the substrate) is not particularly limited, but the pattern is formed on the substrate by performing dry etching on the substrate (or the underlayer film and the substrate) using the pattern formed in step 4 as a mask. The method of forming is preferred.
The dry etching may be one-step etching or multi-step etching. When the etching is an etching consisting of a plurality of stages, the etching of each stage may be the same process or different processes.
Any known method can be used for etching, and various conditions and the like are appropriately determined according to the type and application of the substrate. For example, the Bulletin of the International Society of Optical Engineering (Proc. Of SPIE) Vol. Etching can be performed according to 6924, 692420 (2008), Japanese Patent Application Laid-Open No. 2009-267112, and the like. In addition, the method described in "Chapter 4 Etching" of "Semiconductor Process Textbook 4th Edition 2007 Published Publisher: SEMI Japan" can also be applied.
Of these, oxygen plasma etching is preferable as the dry etching.

Various materials other than the resist composition used in the pattern forming method of the present invention (for example, a developing solution, a rinsing solution, an antireflection film forming composition, a top coat forming composition, etc.) are impurities such as metals (for example, a composition for forming a top coat). The smaller the amount of Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, Zn, etc.), the more preferable. .. The content of impurities contained in these materials is preferably, for example, 1 mass ppm or less.

As a method for reducing impurities such as metals in various materials other than the resist composition, for example, filtration using a filter can be mentioned. The filter pore size is preferably less than 100 nm, more preferably 10 nm or less, and even more preferably 5 nm or less. As the filter, a filter made of polytetrafluoroethylene, polyethylene, or nylon is preferable. The filter may be composed of a composite material in which the above filter material and an ion exchange medium are combined. The filter may be one that has been previously washed with an organic solvent. 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. Further, various materials may be filtered a plurality of times, and the step of filtering the various materials a plurality of times may be a circulation filtration step.

Further, as a method of reducing impurities such as metals in various materials other than the resist composition, a method of selecting a raw material having a low metal content as a raw material constituting various materials, and a filter for the raw material constituting various materials. Examples thereof include a method of performing filtration and a method of performing distillation under conditions in which contamination is suppressed as much as possible by lining the inside of the apparatus with Teflon (registered trademark).

Further, as a method for reducing impurities such as metals in various materials other than the resist composition, impurities may be removed by an adsorbent in addition to the above-mentioned filter filtration, and the filter filtration and the adsorbent may be combined. You may use it. As the adsorbent, a known adsorbent can be used. For example, an inorganic adsorbent such as silica gel and zeolite, and an organic adsorbent such as activated carbon can be used. In order to reduce impurities such as metals contained in various materials other than the resist composition, it is necessary to prevent the mixing of metal impurities in the manufacturing process. Whether or not the metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of the metal components contained in the cleaning liquid used for cleaning the manufacturing equipment.

Conductive compounds are added to organic treatment liquids such as rinse liquids to prevent failures of chemical liquid piping and various parts (filters, O-rings, tubes, etc.) due to static electricity charging and subsequent electrostatic discharge. You may. The conductive compound is not particularly limited, and examples thereof include methanol. The amount to be added is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, from the viewpoint of maintaining preferable development characteristics or rinse characteristics.
As the chemical solution pipe, various pipes coated with SUS (stainless steel) or antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perflooloalkoxy resin, etc.) can be used. Similarly, for the filter and the O-ring, antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used.

A method for improving the surface roughness of the pattern may be applied to the pattern formed by the method of the present invention. Examples of the method for improving the surface roughness of the pattern include a method of treating the pattern with a plasma of a hydrogen-containing gas disclosed in International Publication No. 2014/002808. In addition, JP-A-2004-235468, US Patent Application Publication No. 2010/0020297, JP-A-2008-83384, and Proc. Of SPIE Vol. 8328 83280N-1 "EUV Resist Curing Technology for LWR Reduction and Etch Sensitivity Enhancement" can be mentioned.

When the pattern to be formed is line-shaped, the aspect ratio obtained by dividing the pattern height by the line width is preferably 2.5 or less, more preferably 2.1 or less, still more preferably 1.7 or less. ..
When the pattern to be formed is a trench pattern or a contact hole pattern, the aspect ratio obtained by dividing the pattern height by the trench width or the hole diameter is preferably 4.0 or less, preferably 3.5. The following is more preferable, and 3.0 or less is further preferable.

The pattern forming method of the present invention can also be used for guide pattern forming in DSA (Directed Self-Assembly) (see, for example, ACS Nano Vol. 4 No. 8 Page 4815-4823).

Further, the pattern formed by the above method can be used as, for example, the core material (core) of the spacer process disclosed in JP-A-3-270227 and JP2013-164509.

[Manufacturing method of electronic devices]
The present invention also relates to a method for manufacturing an electronic device, including the above-mentioned pattern forming method. The electronic device is preferably mounted on an electric / electronic device (home appliance, OA (Office Automation), media-related device, optical device, communication device, etc.).

The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the examples shown below.

[Various components of actinic light-sensitive or radiation-sensitive resin composition]
[Acid-degradable resin (resin A)]
The resins A (resins A-1 to A-6, A-8 to A-20) shown in Tables 3 and 7 are shown below.
As the resins A-1 to A-6 and A-8 to A-20, those synthesized according to the method for synthesizing the resin A-1 described later (Synthesis Example 1) were used. Table 1 shows the composition ratio (molar ratio; corresponding in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit shown later.
The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the resins A-1 to A-6 and A-8 to A-20 were measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene equivalent). Is). The composition ratio (mol% ratio) of the resin was measured by ¹³ C-NMR (nuclear magnetic resonance).

The structural formulas of the resins A-1 to A-6 and A-8 to A-20 shown in Table 1 are shown below.

<Synthesis Example 1: Synthesis of Resin A-1>
Cyclohexanone (113 g) was heated to 80 ° C. under a nitrogen stream. While stirring this solution, the monomer represented by the following formula M-1 (25.5 g), the monomer represented by the following formula M-2 (31.6 g), cyclohexanone (210 g), and 2,2'-. A mixed solution of dimethyl azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] (6.21 g) was added dropwise over 6 hours to obtain a reaction solution. After completion of the dropping, the reaction solution was stirred at 80 ° C. for another 2 hours. The obtained reaction solution was allowed to cool, reprecipitated with a large amount of methanol / water (mass ratio 9: 1), filtered, and the obtained solid was vacuum dried to obtain 52 g of resin A-1. ..

The weight average molecular weight (Mw: polystyrene equivalent) determined from the GPC (carrier: tetrahydrofuran (THF)) of the obtained resin A-1 was 6500, and the dispersity (Mw / Mn) was 1.52. ^{13 The} composition ratio measured by C-NMR (nuclear magnetic resonance) was 50/50 in molar ratio.

[Photoacid generator]
<First photoacid generator>
The structures of the photoacid generators B (Compounds B-1 to B-15) shown in Tables 3 and 7 are shown below.
Compounds B-1 to B-15 correspond to the above-mentioned compound (I).

<Second photoacid generator>
The structures of the second photoacid generators (C-1 to C-17) shown in Tables 3 and 7 are shown below.

[Acid diffusion control agent]
The structures of the acid diffusion control agents (Compounds D-1 to D-5) shown in Tables 3 and 7 are shown below.

[Additive resin (resin (B)) and topcoat resin]
The additive resins (E-1 to E-11) shown in Tables 3 and 7 and the topcoat resins (PT-1 to PT-3) shown in Table 5 were synthetic ones.
Table 2 shows the molar ratios and weights of the repeating units in the additive resins (E-1 to E-11) shown in Tables 3 and 7 and the topcoat resins (PT-1 to PT-3) shown in Table 5. The average molecular weight (Mw) and the degree of dispersion (Mw / Mn) are shown.
The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the added resins E-1 to E-11 and the topcoat resins PT-1 to PT-3 were measured by GPC (carrier: tetrahydrofuran (THF)). (It is a polystyrene-equivalent amount). The composition ratio (mol% ratio) of the resin was measured by ¹³ C-NMR (nuclear magnetic resonance).

The monomer structures used for the synthesis of the additive resins E-1 to E-11 and the topcoat resins PT-1 to PT-3 shown in Table 2 are shown below.

[Surfactant]
The surfactants shown in Tables 3, 5 and 7 are shown below.
H-1: Megafuck F176 (manufactured by DIC Corporation, fluorine-based surfactant)
H-3: PF656 (manufactured by OMNOVA, fluorine-based surfactant)

〔solvent〕
The solvents shown in Tables 3 and 7 are shown below.
F-1: Propylene glycol monomethyl ether acetate (PGMEA)
F-2: Propylene glycol monomethyl ether (PGME)
F-4: Cyclohexanone F-5: Cyclopentanone F-6: 2-Heptanone F-7: Ethyl lactate F-8: γ-Butyrolactone F-9: Propylene carbonate

[Preparation and purification of actinic or radiation-sensitive resin compositions, pattern formation, and defect evaluation: ArF immersion exposure]
[Preparation of Actinic Cheilitis or Radiation Sensitive Resin Composition for ArF Immersion Exposure (1)]
Each component shown in Table 3 was mixed so as to have a solid content concentration of 4.0% by mass to prepare an actinic cheilitis or radiation-sensitive resin composition (hereinafter, also referred to as “resist composition”). In the resist composition, the solid content means all components other than the solvent. The obtained resist composition was used in Examples and Comparative Examples.

In Table 3, the content (mass%) of each component means the content with respect to the total solid content.

[Purification of Actinic Photosensitive or Radiation Sensitive Resin Composition for ArF Immersion Exposure (1)]
Each of the obtained resist compositions (Re-1-0 to Re-13-0) was filtered by filtering according to the procedure shown below, and the resist compositions (Re-1-1 to Re-) were subjected to filtration treatment. 13-1) was obtained.

<Various filters>
First, each of the filters shown in Table 4 will be described below.
"Nylon":
Nylon film supported by a support member, critical surface tension: 77dyne / cm
"PE":
Polyethylene membrane supported by a support member, critical surface tension: 36 dyne / cm
"PI":
Polyimide film alone, critical surface tension: 45dyne / cm

<Purification Example 1-1>
First, a filtration facility in which the first filter and the second filter shown in Table 4 are connected in series was prepared. Next, the prepared resist composition (Re-1-0) is passed through the prepared resist composition (Re-1-0) in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-1-1) was obtained.

<Purification Example 1-2>
First, a filtration facility in which the first filter, the second filter, and the third filter shown in Table 4 are connected in series was prepared. Next, the prepared resist composition (Re-2-0) is passed from the first filter to the third filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. As a result, a resist composition (Re-2-1) was obtained.

<Purification Examples 1-3, 1-6>
Filtration of the resist composition (Re-3-0, Re-6-0) by the same method as in Purification Example 1-2 except that the type of resist composition and the type of filter are changed to those shown in Table 4. The treatment was carried out to obtain a resist composition (Re-3-1, Re-6-1).

<Purification Example 1-4>
First, a filtration facility in which the first filter, the second filter, the third filter, and the fourth filter shown in Table 4 are connected in series was prepared. Next, the prepared resist composition (Re-4-0) is passed from the first filter to the fourth filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. As a result, a resist composition (Re-4-1) was obtained.

<Purification Example 1-5>
The resist composition (Re-5-0) was filtered by the same method as in Purification Example 1-1 except that the type of resist composition and the type of filter were changed to those shown in Table 4. The composition (Re-5-1) was obtained.

<Purification Example 1-7>
First, a circulation type filtration facility connecting the first filter and the second filter shown in Table 4 was prepared. Next, the prepared resist composition (Re-7-0) was subjected to 10 in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-7-1) was obtained by circulating the mixture.

<Purification Example 1-8>
First, the first filter and the second filter shown in Table 4 were immersed in propylene glycol monomethyl ether acetate (PGMEA) at 23 ° C. for 6 hours. Then, a filtration facility in which the first filter after immersion and the second filter after immersion are connected in series was prepared. Next, the prepared resist composition (Re-8-0) is passed through the liquid in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. As a result, a resist composition (Re-8-1) was obtained.

<Purification Example 1-9>
First, the first filter and the second filter shown in Table 4 were immersed in propylene glycol monomethyl ether acetate (PGMEA) at 23 ° C. for 12 hours. Then, a circulation type filtration facility in which the first filter after immersion and the second filter after immersion are connected is prepared. Next, the prepared resist composition (Re-9-0) was subjected to 8 in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-9-1) was obtained by circulating the mixture.

<Purification Example 1-10>
The resist composition (Re-10-0) was filtered by the same method as in Purification Example 1-9, except that the type of resist composition and the type of filter were changed to those shown in Table 4. The composition (Re-10-1) was obtained.

<Purification Example 1-11>
The prepared resist composition (Re-11-0) was passed through the first filter shown in Table 4 under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. A resist composition (Re-11-1) was obtained.

<Purification Example 1-12>
The resist composition (Re-12-0) was filtered by the same method as in Purification Example 1-11, except that the type of resist composition and the type of filter were changed to those shown in Table 4. The composition (Re-12-1) was obtained.

<Purification Example 1-13>
The resist composition (Re-13-0) was filtered by the same method as in Purification Example 1-1 except that the type of resist composition and the type of filter were changed to those shown in Table 4. The composition (Re-13-1) was obtained.

Table 4 is shown below.

[Preparation of top coat composition]
The various components contained in the topcoat composition shown in Table 5 are shown below.
<Resin>
As the resin shown in Table 5, the resins PT-1 to PT-3 shown in Table 2 were used.
<Additives>
The structures of the additives shown in Table 5 are shown below.

<Surfactant>
As the surfactant shown in Table 5, the above-mentioned surfactant H-3 was used.

<Solvent>
The solvents shown in Table 5 are shown below.
FT-1: 4-Methyl-2-pentanol (MIBC)
FT-2: n-decane FT-3: diisoamyl ether

<Preparation of top coat composition>
Each component shown in Table 5 was mixed so as to have a solid content concentration of 3.0% by mass, and then the obtained mixed solution was first made of a polyethylene filter having a pore size of 50 nm and then made of nylon having a pore size of 10 nm. A topcoat composition was prepared by filtering in the order of a filter and finally a polyethylene filter having a pore size of 5 nm. The solid content here means all components other than the solvent. The resulting topcoat composition was used in the examples.

[Pattern formation and defect evaluation (1): ArF immersion exposure, alkaline aqueous solution development]
The composition for forming an organic antireflection film ARC29SR (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a film thickness of 98 nm. The resist composition after filtration shown in Table 6 (see Tables 3 and 4 for the composition of the resist composition after filtration) is applied thereto, and the mixture is baked at 100 ° C. for 60 seconds to have a film thickness of 90 nm. A resist film (active light-sensitive or radiation-sensitive film) was formed. In Examples 1-2 and 1-9, a topcoat film was formed on the upper layer of the resist film (the composition of the topcoat composition used is shown in Table 5). The film thickness of the top coat film was 100 nm in each case.
An ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA1.20, Dipole, outer sigma 0.950, inner sigma 0.850, Y-polarized light) was used on the resist film at a line width of 45 nm 1: Exposure was performed through a 6% halftone mask with a 1-line and space pattern. Ultrapure water was used as the immersion liquid.
The resist film after exposure was baked at 90 ° C. for 60 seconds, developed with an aqueous solution of tetramethylammonium hydroxide (2.38% by mass) for 30 seconds, and then rinsed with pure water for 30 seconds.

<Evaluation of defect suppression>
The obtained pattern wafer was inspected with the defect evaluation device UVsion 5 manufactured by Applied Materials, and a defect MAP was prepared. After that, an image of defects was acquired using SEMVision G4 (manufactured by Applied Materials), and the actual number of defects per silicon wafer was calculated. The actual defects generated in the pattern wafer are observed as images as shown in FIGS. 1 and 2, for example.
The actual number of defects obtained was evaluated according to the following evaluation criteria. The smaller the number of defects, the better the result. The evaluation results are shown in Table 6 below.
"S": Number of defects is 50 or less "A": Number of defects is more than 50 and 200 or less "B": Number of defects is more than 200 and 300 or less "C": Number of defects is more than 300 and 400 or less " D ": The number of defects exceeds 400

[Pattern formation and defect evaluation (2): ArF immersion exposure, organic solvent development]
It was developed by paddling with n-butyl acetate as a developer for 30 seconds, then rinsed with 4-methyl-2-pentanol for 30 seconds, and spin-dried to form a 1: 1 line and space with a line width of 45 nm. The pattern formation and the number of defects were evaluated by the same method as in the above-mentioned [Pattern formation and defect evaluation (1): ArF immersion exposure, alkaline aqueous solution development] except that a negative pattern was formed. The evaluation results are shown in Table 6 below.

Table 6 is shown below.
In Table 6, in the "pattern formation method" column, "P" represents alkaline aqueous solution development, and "N" represents organic solvent development.

From the results in Table 6, it is clear that when the resist composition obtained by the method for purifying the resist composition of Examples is used, the defect suppressing property of the formed pattern is excellent.
Further, from the results in Table 6, at least one of the filters X used in the step X is a filter having a critical surface tension of 10 to 39 din / cm, and at least one of the filters X has a critical surface tension of 40. In the case of a filter of ~ 90 dyne / cm, it is clear that the defect suppressing property of the formed pattern is more excellent (except for Examples 1-5). In particular, when the purification method is the following purification method T1 (corresponding to Example 1-8) or the following purification method T2 (Examples 1-7, 1-9, and 1-10). Is applicable), preferably the following purification method T3 (corresponding to Examples 1-9 and 1-10), it is clear that the defect suppressing property of the formed pattern is further excellent.
Purification method T1: A step Y of immersing the filter X used in the step X1 in the organic solvent contained in the resist composition, which comprises the step X1 (single flow type filtration step) and before the step X1 is carried out. Purification method to be carried out.
Purification method T2: A purification method including step X2 (circulation type filtration step).
Purification method T3: A step Y including step X2 (circulation type filtration step) and immersing the filter X used in step X2 in the organic solvent contained in the resist composition is carried out before carrying out step X2. Purification method.

On the other hand, it is clear that the purification methods of Comparative Examples do not meet the desired requirements.
The resist composition Re-14-0 was purified using two types of filters having different critical surface tensions according to the above-mentioned purification method to form a pattern, and one type of filter was used. Almost no difference was observed in the defect suppressing ability of the formed pattern between the case of purifying and forming the pattern. In other words, almost no improvement was observed by purification using two types of filters having different critical surface tensions from each other.
On the other hand, as described above, the purification method of the example using the resist composition containing the first photoacid generator suppresses defects by purifying using two types of filters having different critical surface tensions from each other. The ability was significantly improved.

[Preparation and purification of actinic or radiation-sensitive resin compositions, pattern formation, and defect evaluation: EUV exposure]
[Preparation of Actinic Cheilitis or Radiation Sensitive Resin Composition for EUV Exposure (2)]
Each component shown in Table 7 was mixed so as to have a solid content concentration of 2.0% by mass to prepare an actinic cheilitis or radiation-sensitive resin composition (hereinafter, also referred to as “resist composition”). In the resist composition, the solid content means all components other than the solvent. The obtained resin composition was used in Examples and Comparative Examples.

In Table 7, the content (mass%) of each component means the content with respect to the total solid content.

[Purification of Actinic Cheilitis or Radiation Sensitive Resin Composition for EUV Exposure (2)]
Each of the obtained resist compositions (Re-15-0 to Re-30-0) was filtered by filtering according to the procedure shown below, and the resist compositions (Re-15-1 to Re-) were subjected to filtration treatment. 30-1) was obtained.

<Various filters>
First, each of the filters shown in Table 8 will be described below.
"Nylon":
Nylon film supported by a support member, critical surface tension: 77dyne / cm
"PE":
Polyethylene membrane supported by a support member, critical surface tension: 36 dyne / cm
"PI":
Polyimide film alone, critical surface tension: 45dyne / cm

<Purification Example 2-1>
First, a filtration facility in which the first filter and the second filter shown in Table 8 are connected in series was prepared. Next, the prepared resist composition (Re-15-0) is passed through the first filter to the second filter in this order under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-15-1) was obtained.

<Purification Example 2-2>
First, a filtration facility in which the first filter, the second filter, and the third filter shown in Table 8 are connected in series was prepared. Next, the prepared resist composition (Re-16-0) is passed from the first filter to the third filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. As a result, a resist composition (Re-16-1) was obtained.

<Purification Examples 2-3, 2-6, 2-12>
The resist composition (Re-17-0, Re-20-0, Re-) was prepared in the same manner as in Purification Example 2-2 except that the type of resist composition and the type of filter were changed to those shown in Table 8. The filtration treatment of 26-0) was carried out to obtain a resist composition (Re-17-1, Re-20-1, Re-26-1).

<Purification Example 2-4>
First, a filtration facility in which the first filter, the second filter, the third filter, and the fourth filter shown in Table 8 are connected in series was prepared. Next, the prepared resist composition (Re-18-0) is passed from the first filter to the fourth filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. As a result, a resist composition (Re-18-1) was obtained.

<Purification Examples 2-5, 2-11>
Filtration of the resist composition (Re-19-0, Re-25-0) by the same method as in Purification Example 2-1 except that the type of the resist composition and the type of the filter were changed to those shown in Table 8. The treatment was carried out to obtain a resist composition (Re-19-1, Re-25-1).

<Purification example 2-7>
First, a circulation type filtration facility in which the first filter and the second filter shown in Table 8 are connected was prepared. Next, the prepared resist composition (Re-21-0) was applied to the prepared resist composition (Re-21-0) in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. 6 The resist composition (Re-21-1) was obtained by circulating the mixture.

<Purification Example 2-8>
First, the first filter and the second filter shown in Table 8 were immersed in propylene glycol monomethyl ether acetate (PGMEA) at 23 ° C. for 10 hours. Then, a filtration facility in which the first filter after immersion and the second filter after immersion are connected in series was prepared. Next, the prepared resist composition (Re-22-0) is passed through the liquid in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. As a result, a resist composition (Re-22-1) was obtained.

<Purification Example 2-9>
First, the first filter and the second filter shown in Table 8 were immersed in propylene glycol monomethyl ether acetate (PGMEA) at 23 ° C. for 18 hours. Then, a circulation type filtration facility in which the first filter after immersion and the second filter after immersion are connected is prepared. Next, 10 of the prepared resist composition (Re-23-0) was applied in the order of the first filter to the second filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-23-1) was obtained by circulating the mixture.

<Purification Example 2-10>
First, the first filter, the second filter and the third filter shown in Table 8 were immersed in propylene glycol monomethyl ether acetate (PGMEA) at 23 ° C. for 10 hours. Then, a circulation type filtration facility in which the first filter after immersion, the second filter after immersion, and the third filter after immersion are connected is prepared. Next, the prepared resist composition (Re-24-0) was subjected to 4 in the order of the first filter to the third filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-24-1) was obtained by circulating the mixture.

<Purification Example 2-13>
First, a circulation type filtration facility in which the first filter, the second filter, and the third filter shown in Table 8 are connected was prepared. Next, the prepared resist composition (Re-27-0) was subjected to 12 in the order of the first filter to the third filter under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. The resist composition (Re-27-1) was obtained by circulating the mixture.

<Purification Example 2-14>
The prepared resist composition (Re-28-0) was passed through the first filter shown in Table 8 under the condition of a linear velocity of 40 L / (hr · m ² ) in an environment of 23 ° C. A resist composition (Re-28-1) was obtained.

<Purification Example 2-15>
The resist composition (Re-29-0) was filtered by the same method as in Purification Example 2-16 except that the type of resist composition and the type of filter were changed to those shown in Table 8. The composition (Re-29-1) was obtained.

<Purification Example 2-16>
The resist composition (Re-30-0) was filtered by the same method as in Purification Example 2-1 except that the type of resist composition and the type of filter were changed to those shown in Table 8. The composition (Re-30-1) was obtained.

Table 8 is shown below.

[Pattern formation and defect evaluation (3): EUV exposure, alkaline aqueous solution development]
The underlayer film forming composition AL412 (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205 ° C. for 60 seconds to form a base film having a film thickness of 20 nm. The resist composition after filtration shown in Table 9 (see Tables 7 and 8 for the composition of the resist composition after filtration) is applied thereto, and the mixture is baked at 100 ° C. for 60 seconds to have a film thickness of 30 nm. A resist film was formed.
Using an EUV exposure device (Micro Exposure Tool, NA0.3, Quadrupole, outer sigma 0.68, inner sigma 0.36) manufactured by Exitech, pattern irradiation was performed on the silicon wafer having the obtained resist film. It was. As the reticulum, a mask having a line size of 20 nm and a line: space = 1: 1 was used.
The resist film after exposure was baked at 90 ° C. for 60 seconds, developed with an aqueous solution of tetramethylammonium hydroxide (2.38% by mass) for 30 seconds, and then rinsed with pure water for 30 seconds.

<Evaluation of defect suppression>
The obtained pattern wafer was inspected with the defect evaluation device UVsion 5 manufactured by Applied Materials, and a defect MAP was prepared. After that, an image of defects was acquired using SEMVision G4 (manufactured by Applied Materials), and the actual number of defects per silicon wafer was calculated. The actual defects generated in the pattern wafer are observed as images as shown in FIGS. 1 and 2, for example.
The actual number of defects obtained was evaluated according to the following evaluation criteria. The smaller the number of defects, the better the result. The evaluation results are shown in Table 9 below.
"S": Number of defects is 50 or less "A": Number of defects is more than 50 and 200 or less "B": Number of defects is more than 200 and less than 300 "C": Number of defects is more than 300 and 400 or less " D ": The number of defects exceeds 400

[Pattern formation and defect evaluation (4): EUV exposure, organic solvent development]
Above, except that n-butyl acetate was used as a developer for 30 seconds to develop, and then spin-dried to form a line-and-space negative pattern with a pitch of 40 nm and a line width of 20 nm (space width of 20 nm). Pattern formation and defect number evaluation were carried out by the same method as in [Pattern formation and defect evaluation (3): EUV exposure, alkaline aqueous solution development]. The evaluation results are shown in Table 9 below.

Table 9 is shown below.
In Table 9, in the "pattern formation method" column, "P" represents alkaline aqueous solution development, and "N" represents organic solvent development.

From the results in Table 9, it is clear that when the resist composition obtained by the method for purifying the resist composition of Examples is used, the defect suppressing property of the formed pattern is excellent.
Further, from the results in Table 9, at least one of the filters used in step X is a filter having a critical surface tension of 10 to 39 din / cm, and at least one of the filters has a critical surface tension of 40 to 40 to. In the case of a 90 yne / cm filter (other than Examples 2-5), it is clear that the defect suppression property of the formed pattern is better. In particular, when the purification method is the following purification method T1 (corresponding to Example 2-8) or the following purification method T2 (Example 2-7, Example 2-9, Example 2-10, And Example 2-13), preferably the following purification method T3 (Applicable to Examples 2-9 and 2-10), the defect suppression property of the formed pattern is further excellent. it is obvious.
Purification method T1: A step Y of immersing the filter X used in the step X1 in the organic solvent contained in the resist composition, which comprises the step X1 (single flow type filtration step) and before the step X1 is carried out. Purification method to be carried out.
Purification method T2: A purification method including step X2 (circulation type filtration step).
Purification method T3: A step Y including step X2 (circulation type filtration step) and immersing the filter X used in step X2 in the organic solvent contained in the resist composition is carried out before carrying out step X2. Purification method.

On the other hand, it is clear that the purification methods of Comparative Examples do not meet the desired requirements.
The resist composition Re-31-0 is purified using two types of filters having different critical surface tensions to form a pattern according to the above-mentioned purification method, and one type of filter is used. Almost no difference was observed in the defect suppressing ability of the formed pattern between the case of purifying and forming the pattern. In other words, almost no improvement was observed by purification using two types of filters having different critical surface tensions from each other.
On the other hand, as described above, the purification method of the example using the resist composition containing the first photoacid generator suppresses defects by purifying using two types of filters having different critical surface tensions from each other. The ability was significantly improved.

Claims

A method for purifying a sensitive light-sensitive or radiation-sensitive resin composition containing at least a resin whose polarity is increased by the action of an acid, a compound that generates an acid by irradiation with active light or radiation, and a solvent.
The compound that generates an acid by irradiation with active light or radiation contains one or more compounds selected from the group consisting of the following compounds (I) to the following compounds (III).
A method for purifying an actinic or radiation-sensitive resin composition, which comprises step X in which the actinic or radiation-sensitive resin composition is passed through two or more types of filters and filtered.
Compound (I): A compound having one of the following structural sites X and one of the following structural sites Y, and the following first acidic site and the following structure derived from the following structural site X by irradiation with active light or radiation. compound structure sites of generating an acid comprising the following second acidic site derived from the site Y X: anionic part a 1 - consists of a cationic sites M 1 + and Table in HA 1 by and exposed to actinic rays or radiation the first structural portion structural site to form an acidic site Y that is: anionic part a 2 - consists of a cationic sites M 2 + and, and by irradiation with actinic rays or radiation, the formed by the structural moiety X The structural site forming the second acidic site represented by HA 2 having a structure different from that of the first acidic site. However, the compound (I) satisfies the following condition I.
Condition I: In the compound (I), the compound PI obtained by replacing the cation site M 1 + in the structural site X and the cation site M 2 + in the structural site Y with H + is contained in the structural site X. The acid dissociation constant a1 derived from the acidic site represented by HA 1 , which is obtained by replacing the cation site M 1 + with H + , and the cation site M 2 + in the structural site Y are replaced with H +. It has an acid dissociation constant a2 derived from an acidic moiety represented by HA 2 , and the acid dissociation constant a2 is larger than the acid dissociation constant a1.
Compound (II): A compound having two or more structural sites X and the structural site Y, and having two first acidic sites derived from the structural site X by irradiation with active light or radiation. A compound that generates an acid containing the above and the second acidic moiety derived from the structural moiety Y. However, the compound (II) satisfies the following condition II.
Condition II: In the compound (II), the compound PII obtained by replacing the cation site M 1 + in the structural site X and the cation site M 2 + in the structural site Y with H + is contained in the structural site X. The acid dissociation constant a1 derived from the acidic site represented by HA 1 , which is obtained by replacing the cation site M 1 + with H + , and the cation site M 2 + in the structural site Y are replaced with H +. It has an acid dissociation constant a2 derived from an acidic moiety represented by HA 2 , and the acid dissociation constant a2 is larger than the acid dissociation constant a1.
Compound (III): A compound having two or more of the structural site X and the following structural site Z, wherein the first acidic site derived from the structural site X is 2 by irradiation with active light or radiation. A compound that generates an acid containing one or more of the structural site Z Structural site Z: A nonionic site capable of neutralizing the acid
The method for purifying a sensitive light-sensitive or radiation-sensitive resin composition according to claim 1, wherein the critical surface tension of the filter is 10 to 90 dyne / cm.
The method for purifying an actinic or radiation-sensitive resin composition according to claim 1 or 2, wherein the critical surface tension of at least one of the filters is 40 to 90 dyne / cm.
Any of claims 1 to 3, wherein at least one of the filters has a critical surface tension of 40 to 90 dyne / cm and at least one of the filters has a critical surface tension of 10 to 39 dyne / cm. The method for purifying a sensitive light-sensitive or radiation-sensitive resin composition according to item 1.
In the step X, the sensitive light-sensitive or radiation-sensitive resin composition is passed through two or more types of filters arranged in the flow path to filter, and then the sensitive light-sensitive or radiation-sensitive radiation that has passed through the filter. The method for purifying an actinic cheilitis or radiation-sensitive resin composition according to any one of claims 1 to 4, which is a step X2 in which the sex resin composition is further guided to the same filter and filtered again.
The actinic or radiation-sensitive resin according to any one of claims 1 to 5, further comprising a step Y of immersing the filter used in the step X in an organic solvent before the step X. Method for purifying the composition.
The sensitive light-sensitive or radiation-sensitive resin composition contains an organic solvent and contains
The sensitive light-sensitive or radiation-sensitive resin composition according to claim 6, wherein the organic solvent for immersing the filter and the organic solvent contained in the sensitive light-sensitive or radiation-sensitive resin composition are of the same type. Purification method.
A step of purifying the sensitive light-sensitive or radiation-sensitive resin composition by the method for purifying the sensitive light-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 7.
A step of forming a resist film on a support using the purified actinic cheilitis or radiation-sensitive resin composition, and
The step of exposing the resist film and
A pattern forming method comprising a step of developing the exposed resist film with a developing solution.
A method for manufacturing an electronic device, including the pattern forming method according to claim 8.