JP7301123B2 - Actinic ray-sensitive or radiation-sensitive resin composition production method, pattern formation method, electronic device production method - Google Patents

Description

The present invention relates to a method for producing an actinic ray-sensitive or radiation-sensitive resin composition, a pattern forming method, 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 in order to compensate for the decrease in sensitivity due to light absorption. For example, in a positive chemical amplification method, first, a photoacid generator contained in an exposed area is decomposed by light irradiation to generate an acid. Then, in the post-exposure baking (PEB: Post Exposure Bake) process or the like, the alkali-insoluble groups of the resin contained in the actinic ray-sensitive or radiation-sensitive resin composition are converted into alkali-soluble groups by the catalytic action of the generated acid. The solubility in the developer is changed by, for example, changing the base. Thereafter, development is performed using, for example, a basic aqueous solution. Thereby, the exposed portion is removed to obtain a desired pattern.
For the miniaturization of semiconductor devices, the wavelength of the exposure light source is shortened and the numerical aperture (NA) of the projection lens is increased. Currently, an exposure machine using an ArF excimer laser with a wavelength of 193 nm as a light source has been developed. ing. Under such circumstances, various structures have been proposed as actinic ray-sensitive or radiation-sensitive resin compositions (resist compositions).

Furthermore, in recent years, along with the demand for further miniaturization of resist patterns, improvement of resist pattern surface defects after development is even more desired.
For example, in Patent Document 1, a resist composition containing a resin component, an acid-generating component that generates an acid upon exposure, and an organic solvent is subjected to filtering under specific conditions to obtain a resist pattern surface after development. A method for suppressing defects is disclosed.

Patent No. 04637967

The inventors of the present invention prepared and studied a resist composition with reference to Patent Document 1, and found that surface defects (especially bridge defects) still occurred on the pattern formed by the resist composition. .

Accordingly, an object of the present invention is to provide a method for producing an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a pattern in which bridging defects are suppressed.
Another object of the present invention is to provide a pattern forming method using an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a pattern in which bridging defects are suppressed, and a method for manufacturing an electronic device.

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that the above problems can be solved by the following configuration.

[1] A method for producing an actinic ray-sensitive or radiation-sensitive resin composition used in a semiconductor device manufacturing process, comprising:
A step A of purifying a polymer solution containing a resin that is decomposed by the action of an acid to increase its polarity and a solvent;
A step B of adding a compound that generates an acid upon exposure to actinic rays or radiation to the polymer solution that has undergone step A to prepare an actinic ray-sensitive or radiation-sensitive resin composition,
A method for producing an actinic ray-sensitive or radiation-sensitive resin composition, wherein the step A includes a step X of filtering the polymer solution through a filter X.
[2] The filter X is selected from the group consisting of a nylon membrane with a pore size of 0.03 μm or less, a polyolefin resin membrane with a pore size of 0.01 μm or less, and a fluororesin membrane with a pore size of 0.01 μm or less [1] A method for producing the actinic ray-sensitive or radiation-sensitive resin composition according to 1.
[3] The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the filter X has a differential pressure of 0.3 MPa or less.
[4] The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [3], wherein the step X is carried out in a temperature environment of 15 to 25°C.
[5] The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein the step A includes the step X two or more times.
[6] The above step A is
a step X0 of filtering the polymer solution through a filter X0; and a step X1 of filtering the polymer solution that has undergone the step X0 through a filter X1;
A step X1 of filtering the polymer solution through a filter X1, and a step X2 of filtering the polymer solution that has undergone the step X1 through a filter X2, or
A step X0 of filtering the polymer solution through a filter X0, a step X1 of filtering the polymer solution that has undergone the step X0 through a filter X1, and a step X1 of filtering the polymer solution that has undergone the step X1 through a filter X2. and a step X2 of allowing and filtering,
[1] to [ 4].
[7] The above step A is
a step X0 of filtering the polymer solution through a filter X0; and a step X1 of filtering the polymer solution that has undergone the step X0 through a filter X1. and again include the step of performing the step X0 and the step X1 one or more times,
a step X1 of filtering the polymer solution through a filter X1; and a step X2 of filtering the polymer solution that has undergone the step X1 through a filter X2. and again includes the step of performing the step X1 and the step X2 one or more times, or
A step X0 of filtering the polymer solution through a filter X0, a step X1 of filtering the polymer solution that has undergone the step X0 through a filter X1, and a step X1 of filtering the polymer solution that has undergone the step X1 through a filter X2. and filtering, and the step of once or more performing the steps X0, X1, and X2 again on the polymer solution that has undergone the step X2. A method for producing the described actinic ray-sensitive or radiation-sensitive resin composition.
[8] The actinic ray-sensitive or according to [6] or [7], wherein the differential pressure of the filter X0, the differential pressure of the filter X1, and the differential pressure of the filter X2 are all 0.3 MPa or less. A method for producing a radiation-sensitive resin composition.
[9] Any one of [1] to [8], wherein the resin that is decomposed by the action of an acid to increase polarity includes a resin containing a repeating unit derived from at least one of an acrylic acid ester and a methacrylic acid ester. A method for producing the actinic ray-sensitive or radiation-sensitive resin composition according to 1.
[10] Actinic ray-sensitive or radiation-sensitive according to any one of [1] to [9], wherein the resin that is decomposed by the action of an acid to increase its polarity contains one or more of a carbonate structure and a sultone structure. a method for producing a flexible resin composition.
[11] Using an actinic ray- or radiation-sensitive resin composition produced by the method for producing an actinic ray- or radiation-sensitive resin composition according to any one of [1] to [10], supporting a step of forming a resist film on the body;
exposing the resist film;
and developing the exposed resist film using a developer.
[12] A method for manufacturing an electronic device, including the pattern forming method according to [11].

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the actinic-ray-sensitive or radiation-sensitive resin composition which can form the pattern by which bridge|bridging defect was suppressed can be provided.
Further, the present invention can provide a pattern forming method using an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a pattern in which bridging defects are suppressed, and a method for manufacturing an electronic device.

It is the schematic of the apparatus for demonstrating an example of embodiment of process A. FIG. It is the schematic of the apparatus for demonstrating an example of embodiment of process A. FIG. It is the schematic of the apparatus for demonstrating an example of embodiment of process A. FIG. It is the schematic of the apparatus for demonstrating an example of embodiment of process A. FIG.

The present invention will be described in detail below.
The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.
Regarding the notation of groups (atomic groups) in the present specification, as long as it does not contradict the spirit of the present invention, the notation that does not indicate substituted or unsubstituted includes groups having substituents as well as groups not having substituents. do. For example, an "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). Also, the term "organic group" as used herein refers to a group containing at least one carbon atom.
The substituent is preferably a monovalent substituent unless otherwise specified.
The term "actinic rays" or "radiation" as used herein means, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV light: Extreme Ultraviolet), X-rays, and electron beams (EB : Electron Beam) and the like. As used herein, "light" means actinic rays or radiation.
The term "exposure" as used herein means, unless otherwise specified, not only exposure by the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays, X-rays, and EUV light, but also electron beams, and It also includes drawing with particle beams such as ion beams.
In the present specification, the term "~" is used to include the numerical values before and after it as lower and upper limits.
The bonding direction of the divalent groups described herein is not limited unless otherwise specified. For example, in the compound represented by the general formula "XYZ", when Y is -COO-, Y may be -CO-O- or -O-CO- may Further, the above compound may be "X--CO--O--Z" or "X--O--CO--Z."

As used herein, (meth)acrylate refers to acrylate and methacrylate, and (meth)acryl refers to acrylic and methacrylic.
In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also referred to as molecular weight distribution) (Mw/Mn) of the resin are measured using a GPC (Gel Permeation Chromatography) device (HLC-8120GPC manufactured by Tosoh Corporation). ) by GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40 ° C., flow rate: 1.0 mL / min, detector: differential refractive index It is defined as a polystyrene conversion value by a detector (Refractive Index Detector).

As used herein, the acid dissociation constant (pKa) represents the pKa in an aqueous solution. , is a calculated value. All pKa values described herein are calculated using this software package.

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

As used herein, halogen atoms include, for example, fluorine, chlorine, bromine, and iodine atoms.

[Method for producing actinic ray-sensitive or radiation-sensitive resin composition]
The method for producing the actinic ray-sensitive or radiation-sensitive resin composition (hereinafter also referred to as "resist composition") of the present invention (hereinafter also referred to as "the manufacturing method of the present invention") comprises the following step A and the following Including step B.
Step A: A step of purifying a polymer solution containing a resin that is decomposed by the action of an acid to increase its polarity (hereinafter also referred to as “acid-decomposable resin”) and a solvent, wherein the polymer solution is filtered through a filter X and filtering through step X.
Step B: A compound that generates an acid upon exposure to actinic rays or radiation (hereinafter also referred to as a "photoacid generator") is added to the polymer solution that has undergone the above step A to form an actinic ray-sensitive or radiation-sensitive resin composition. the process of adjusting things

In the production of a resist composition, filtration purification by filtering is generally carried out at the stage of preparation of the resist composition.
Recently, the present inventors have found that in filtration purification by filtering in the post-preparation stage of the resist composition, impurities mixed in the raw material components and brought into the resist composition (hereinafter also referred to as "impurities derived from raw materials") are removed. Among them, impurities containing metal atoms derived from the acid-decomposable resin (hereinafter also referred to as "metal impurities") and by-products (by-products include low-molecular-weight substances, super-molecular-weight substances, and gel components ) is not completely removed, and forms fine aggregates in the resist composition, thereby causing bridging defects on the pattern.
In contrast, in the production method of the present invention, when preparing a resist composition containing an acid-decomposable resin, a photoacid generator, and a solvent, first, the polymer solution containing the acid-decomposable resin and the solvent is filtered. to reduce the amount of impurity components derived from the acid-decomposable resin, and a photoacid generator is added to the resulting polymer solution after purification. As a result, in the resist composition obtained by the production method of the present invention, the number of fine aggregates generated in the resist composition is reduced, and it is believed that bridging defects generated on the pattern after development can be suppressed. be done. In particular, when the acid-decomposable resin contains one or more of a carbonate structure and a sultone structure, the effect of reducing specific metal impurities in step A is superior, and as a result, bridge defects occurring on the pattern after development can be further suppressed. is confirmed.

The steps A and B included in the manufacturing method of the present invention will be described below.
[Step A]
Step A is a step of purifying a polymer solution containing an acid-decomposable resin and a solvent, and is a step X of filtering the polymer solution through a filter X (hereinafter also referred to as “step X”). including.

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

The material of the filter X is not particularly limited, but examples thereof include polyamide resin, polyolefin resin, and fluororesin.
As the polyamide resin, nylon (nylon includes nylon 6, nylon 66, nylon 46, etc.) is preferable.
Polyethylene or polypropylene is preferable as the polyolefin resin.
As the fluorine resin, PTFE (polytetrafluoroethylene) is preferable.
As the material of the filter X, polyamide resin or polyolefin resin is particularly preferable. When the filter X is a polyamide resin film, it is considered that the amount of impurities in the polymer solution can be reduced because the amide sites in the resin adsorb impurities. Moreover, when the filter X is a polyolefin resin film, impurities are removed by its pore diameter. The metal impurities contained in the impurities are chemically and/or It is speculated that much of it is removed from the polymer solution during filtering due to physical attachment.

Although the pore size of the filter X is not particularly limited, it is, for example, 0.5 μm or less, preferably 0.4 μm or less, and more preferably 0.3 μm or less from the viewpoint of filtration efficiency. Although the lower limit of the pore size is not particularly limited, it is, for example, 0.001 μm or more. In addition, in this specification, the "pore diameter" intends the nominal diameter value of the manufacturer.

As the filter X, among others, a nylon film with a pore size of 0.03 μm or less, a polyolefin resin film with a pore size of 0.01 μm or less, or a pore size of 0.01 μm or less is used in order to further suppress bridging defects in the formed pattern. A fluororesin film having a thickness of 01 μm or less is preferable.

Step A may include step X once, or may include step X twice or more.
When step A includes step X two or more times, step A may be a one-time passing method in which the polymer solution is passed once through a system in which two or more filters X are connected in series. A circulation system may be used in which the polymer solution that has passed through X is further led to the same filter and circulated in a closed system. In addition, the process A may be a system in which a one-time passing system in which the polymer solution is passed once through a system in which two or more filters X are connected in series is repeated multiple times.

When step A includes step X two or more times, the number of times is not particularly limited, but is, for example, two or more, preferably three or more. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less. When the process A is carried out in a circulation system, for example, when there is one filter X in the closed system, the number of circulations of the polymer solution is, for example, two or more, preferably three or more. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less.

When the process X is performed twice or more by the single-pass method, the plurality of filters X may be the same or different. In this specification, the phrase "the plurality of filters are different" means that the plurality of filters are different in pore size and/or material.

In the process X, the differential pressure of the filter X (meaning the pressure loss across the filter X) is preferably 0.3 MPa or less. Although the lower limit is not particularly limited, 0 MPa can be mentioned.

When step A includes step X two or more times, step A includes the following step (1), step (2), or step (3) in that bridge defects in the formed pattern are further suppressed. is preferred.
Step (1): includes a step X0 of filtering the polymer solution through a filter X0 and a step X1 of filtering the polymer solution that has passed through the step X0 through a filter X1.
Step (2): includes a step X1 of filtering the polymer solution through a filter X1 and a step X2 of filtering the polymer solution that has passed through the step X1 through a filter X2.
Step (3): Step X0 of passing the polymer solution through the filter X0 and filtering; Step X1 of passing the polymer solution that has undergone the step X0 through the filter X1 and filtering; and Passing the polymer solution that has undergone the step X1 through the filter X2. and a step X2 of filtering.

Further, steps (1) to (3) are preferably carried out in a temperature environment of 15 to 25°C. Each of steps (1) to (3) will be described in detail below.

<Step (1)>
≪Step X0≫
As the filter X0, if it is a filter different from the filter X1 used in the step X1 and is selected from a polyolefin resin membrane with a pore size of 0.01 μm or less and a fluororesin membrane with a pore size of 0.01 μm or less. There are no particular restrictions.
The lower limit of the pore size of the polyolefin resin membrane having a pore size of 0.01 μm or less is, for example, 0.001 μm or more. Polyethylene or polypropylene is preferable as the polyolefin resin forming the polyolefin resin film.
The lower limit of the pore diameter of the fluororesin membrane having a pore diameter of 0.01 μm or less is, for example, 0.001 μm or more. PTFE is preferable as the fluororesin constituting the fluororesin membrane.

≪Step X1≫
The filter X1 is synonymous with the filter X used in the above-described process X, and the preferred embodiment is also the same.
The procedure of step X1 is also the same as the procedure of step X described above.

In the process X0 and the process X1, it is preferable that the differential pressure of the filter X0 (meaning the pressure loss before and after the filter X0) and the differential pressure of the filter X1 are respectively 0.3 MPa or less. Although the lower limit is not particularly limited, 0 MPa can be mentioned.

Step A may include step (1) once or two or more times. In addition, the case where step A includes step (1) two or more times means that step A includes the step of performing step X0 and step X1 again on the polymer solution that has undergone step X1 once or more. Intend.
When step A includes step (1) two or more times, step (1) includes passing the polymer solution once through a system in which filters X0 and X1 are alternately connected in series in this order. A flow system may be used, or a circulation system may be used in which the polymer solution that has passed through the filters X0 and X1 in this order is further led to the same filter X0 and circulated in a closed system.

When step A includes step (1) two or more times, the number of times is not particularly limited, but is, for example, two or more, preferably three or more. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less. In the case where step (1) is carried out in a circulation system, for example, when there is one filter X0 and one filter X1 in the closed system, the number of circulations of the polymer solution is, for example, 2 or more, or 3 or more. is preferred. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less.

When the step (1) is performed twice or more by the one-time passing method, the plurality of filters X0 and the plurality of filters X1 may be the same or different.

In step (1), when the materials of the filter X0 and the filter X1 are different, there is an aspect in which the filter X0 is made of polyolefin resin and the filter X1 is made of polyamide resin. In step (1), when the filter X0 and the filter X1 have different pore diameters, the pore diameter of the filter X0 is preferably larger than that of the filter X1. The difference between the pore diameter of the filter X1 and the pore diameter of the filter X0 is preferably 0.001 to 0.2 μm, for example.

<Step (2)>
≪Step X1≫
The filter X1 is synonymous with the filter X used in the above-described process X, and the preferred embodiment is also the same.
The procedure of step X1 is also the same as the procedure of step X described above.

≪Step X2≫
As the filter X2, if it is a filter different from the filter X1 used in the step X1 and is selected from a polyolefin resin membrane with a pore size of 0.01 μm or less and a fluororesin membrane with a pore size of 0.01 μm or less. There are no particular restrictions.
The lower limit of the pore size of the polyolefin resin membrane having a pore size of 0.01 μm or less is, for example, 0.001 μm or more. Polyethylene or polypropylene is preferable as the polyolefin resin forming the polyolefin resin film.
The lower limit of the pore diameter of the fluororesin membrane having a pore diameter of 0.01 μm or less is, for example, 0.001 μm or more. PTFE is preferable as the fluororesin constituting the fluororesin membrane.

In the steps X1 and X2, the differential pressure across the filter X1 and the differential pressure across the filter X2 (meaning the pressure loss across the filter X2) are each preferably 0.3 MPa or less. Although the lower limit is not particularly limited, 0 MPa can be mentioned.

Step A may include step (2) once or two or more times. In addition, the case where the step A includes the step (2) two or more times means that the step A includes the step of performing the steps X1 and X2 again on the polymer solution that has undergone the step X2 once or more. Intend.
When step A includes step (2) two or more times, step (2) includes passing the polymer solution once through a system in which filters X1 and X2 are alternately connected in series in this order. A liquid flow system may be used, or a circulation system may be used in which the polymer solution that has passed through the filter X1 and the filter X2 in this order is further led to the same filter X1 and circulated in a closed system.

When step A includes step (2) two or more times, the number of times is not particularly limited, but is, for example, two or more, preferably three or more. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less. In the case where step (2) is carried out in a circulation system, for example, when there is one filter X1 and one filter X2 in the closed system, the number of circulations of the polymer solution is, for example, two or more times, or three or more times. is preferred. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less.

When the step (2) is performed twice or more by the one-time passing method, the plurality of filters X1 and the plurality of filters X2 may be the same or different.

In the step (2), when the filter X1 and the filter X2 are made of different materials, the filter X1 may be made of a polyamide resin and the filter X2 may be made of a polyolefin resin. In step (2), when the pore diameters of the filters X1 and X2 are different, it is preferable that the pore diameter of the filter X1 is larger than that of the filter X2. The difference between the pore diameter of the filter X2 and the pore diameter of the filter X1 is preferably 0.001 to 0.2 μm, for example.

<Step (3)>
≪Step X0≫
The step X0 has the same meaning as the step X0 in the step (1) described above, and the preferred embodiments are also the same.

≪Step X1≫
The filter X1 is synonymous with the filter X used in the above-described process X, and the preferred embodiment is also the same.
The procedure of step X1 is also the same as the procedure of step X described above.

≪Step X2≫
Step X2 is a step of filtering the polymer solution that has undergone Step X1 through a filter X2, and is the same as Step X2 in Step (2) described above, except that the polymer solution that has undergone Step X1 is subjected to filtration purification. The same is true, and the preferred embodiments are also the same.

In steps X0, X1, and X2, the differential pressure across the filter X0, the differential pressure across the filter X1, and the differential pressure across the filter X2 are each preferably 0.3 MPa or less. Although the lower limit is not particularly limited, 0 MPa can be mentioned.

Step A may include step (3) once or two or more times. Note that the case where step A includes step (3) two or more times means that the step of performing step X0, step X1, and step X2 again on the polymer solution that has undergone step X2 is included one or more times. Intend.
When step A includes step (3) two or more times, step (3) passes the polymer solution once through a system in which filter X0, filter X1, and filter X2 are alternately connected in series in this order. Alternatively, the polymer solution passed through the filters X0, X1 and X2 in this order may be led to the same filter X0 and circulated in a closed system.

When step A includes step (3) two or more times, the number of times is not particularly limited, but is, for example, two or more, preferably three or more. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less. In the case where step (3) is carried out in a circulation system, for example, when there is one filter X0, one filter X1, and one filter X2 in the closed system, the number of circulations of the polymer solution is, for example, two or more. , preferably 3 or more times. Although the upper limit is not particularly limited, it is, for example, 15 times or less, preferably 10 times or less.

When the step (3) is performed twice or more by a single flow method, the plurality of filters X0, the plurality of filters X1, and the plurality of filters X2 may be the same or different. may be

In step (3), when the filter X0 and the filter X1 are made of different materials, the filter X0 may be made of polyolefin resin or fluororesin, and the filter X1 may be made of polyamide resin. In step (3), when the pore diameters of the filter X0 and the filter X1 are different, it is preferable that the pore diameter of the filter X0 is larger than that of the filter X1. The difference between the pore diameter of the filter X1 and the pore diameter of the filter X0 is preferably 0.001 to 0.2 μm, for example.
In the step (3), when the filter X1 and the filter X2 are made of different materials, the filter X1 may be made of polyamide resin, and the filter X2 may be made of polyolefin resin or fluororesin. In step (3), when the pore diameters of the filters X1 and X2 are different, it is preferable that the pore diameter of the filter X1 is larger than that of the filter X2. The difference between the pore diameter of the filter X2 and the pore diameter of the filter X1 is preferably 0.001 to 0.2 μm, for example.
In step (3), it is preferable that the filters X0 and X2 are made of different materials. Moreover, it is preferable that the filter X2, the filter X1, and the filter 0 have larger pore sizes in this order.

<Other optional steps>
The production method of the present invention may optionally include steps other than steps A and B.
Other steps include step Z (hereinafter also referred to as “step Z”) of measuring the content of metal impurities (impurities containing metal atoms) that may be contained in the polymer solution obtained through step A. . The term “metal impurities” means impurities contained in the polymer solution as metal ions and solids (including simple metals and particulate metal-containing compounds).
In the semiconductor device manufacturing process, it is required to reduce metal impurities in the resist composition. The types of metal atoms in the metal impurities are not particularly limited, but metals whose content in the resist composition is desired to be small include, for example, Na, K, Ca, Fe, Cu, Mg, Mn, Al, Metal atoms such as Li, Cr, Ni, Sn, Zn, Ag, As, Au, Ba, Cd, Co, Pb, V, W, Zr, and Mo (hereinafter also referred to as “specific metal atoms”). be done.
In this specification, the content of metal impurities in the polymer solution means the content of metal atoms measured by ICP-MS (inductively coupled plasma mass spectrometry). The method for measuring the content of metal atoms using ICP-MS is as described in Examples below.

The content of each metal atom (particularly the specific metal atom) is preferably 100 mass ppb or less, more preferably 50 mass ppb or less, still more preferably 20 mass ppb or less, particularly 10 mass ppb, relative to the total mass of the solution. It is preferably 5.0 mass ppb or less, most preferably 1.0 mass ppb or less. The lower limit of the content of each metal atom is preferably not substantially contained (below the detection limit of the measuring device), and more preferably 0.
Further, the total content of the specific metal atoms in the polymer solution is preferably 100 mass ppb or less, more preferably 50 mass ppb or less, still more preferably 20 mass ppb or less, and 10 mass ppb or less with respect to the total mass of the solution. Particularly preferred is 5.0 mass ppb or less, most preferably 1.0 mass ppb or less. The lower limit of the total content of the specific metal atoms is preferably not substantially contained (below the detection limit of the measuring device), and more preferably 0.

Below, an example of embodiment of the process A is described with reference to drawings. 1-4 are schematic diagrams of the equipment used in step A. FIG.

The apparatus of FIG. 1 is an apparatus used when the process A is a mode in which the process X is performed only once by a one-time feeding method.
In the apparatus of FIG. 1, a tank 1, a pump 2, and a column 100 provided with a filter X are connected by channels 5-7. Furthermore, a flow meter 3 and a filling port 8 are installed in the flow path 7 . By driving the pump 2 , the polymer solution filled in the tank 1 passes through the column 100 in which the filter X is installed, and the polymer solution that has passed through the column 100 is filled in the processing liquid filling container 4 .

The apparatus of FIG. 2 is an apparatus used when the process A is a mode in which the process X is performed two or more times in a circulating manner.
In the apparatus of FIG. 2, a tank 1, a pump 2, and a column 100 provided with a filter X are connected by channels 5-7.
The flow path 7 is also connected to the tank 1, and by driving the pump 2, the polymer solution contained in the tank 1 is circulated within the system. Further, a filling port 8 is provided in the flow path 7 so that the treatment liquid filling container 4 is filled with the polymer solution that has undergone a predetermined circulating filtration process.
Here, in many cases, the filling port 8 is closed at the start of driving the pump so that a predetermined number of circulations can be achieved.
The number of times of circulation can be calculated using the flow meter 3 installed in the flow path 7 .

The apparatus of FIG. 3 is an apparatus used when the process A is a mode in which the process (3) is performed only once by a one-time feeding method.
In the apparatus of FIG. 3, a tank 1, a pump 2, a column 200 equipped with a filter X0, a column 300 equipped with a filter X1, and a column 400 equipped with a filter X2 are connected to channels 5, 6, 7, and 9. , and 10. Furthermore, a flow meter 3 and a filling port 8 are installed in the flow path 7 . By driving the pump 2 , the polymer solution filled in the tank 1 passes through the columns 200 , 300 and 400 , and the polymer solution that has passed through the column 400 is filled into the treatment liquid container 4 .

The apparatus of FIG. 4 is an apparatus used when step A is a mode in which step (3) is carried out in a circulating manner.
In the apparatus of FIG. 4, a tank 1, a pump 2, a column 500 equipped with a filter X0, a column 600 equipped with a filter X1, and a column 700 equipped with a filter X2 are connected to channels 5, 6, 7, and 9. , and 10.
The flow path 7 is also connected to the tank 1, and by driving the pump 2, the polymer solution contained in the tank 1 is circulated within the system. Further, a filling port 8 is provided in the flow path 7 so that the treatment liquid filling container 4 is filled with the polymer solution that has undergone a predetermined circulating filtration process.
Here, in many cases, the filling port 8 is closed at the start of driving the pump so that a predetermined number of circulations can be achieved.
The number of times of circulation can be calculated using the flow meter 3 installed in the flow path 7 .

<Polymer solution>
Next, the polymer solution will be explained.
The polymer solution contains an acid-decomposable resin and a solvent.
It is preferable that the polymer solution does not substantially contain a compound (photoacid generator) that generates an acid upon exposure to actinic rays or radiation. Here, "the polymer solution does not substantially contain a photo-acid generator" means that the content of the photo-acid generator is 3.0% by mass or less with respect to the total mass of the polymer solution. , preferably 2.0% by mass or less, more preferably 1.0% by mass or less.
Among others, it is preferable that the polymer solution does not substantially contain other components than the acid-decomposable resin and the solvent. Here, "the polymer solution does not substantially contain components other than the acid-decomposable resin and the solvent" means that the total content of the components other than the acid-decomposable resin and the solvent is equal to that of the polymer solution. It is intended to be 3.0% by mass or less, preferably 2.0% by mass or less, more preferably 1.0% by mass or less, relative to the total mass.

(Acid-decomposable resin (resin (A)))
The polymer solution contains a resin (“acid-decomposable resin” or “resin (A)”) that is decomposed by the action of acid to increase its polarity.
The acid-decomposable resin usually contains a repeating unit having a group that is decomposed by the action of an acid to increase its polarity (hereinafter also referred to as "acid-decomposable group").
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 negative pattern is preferably formed. formed in

•Repeating unit having an acid-decomposable group The resin (A) preferably contains a repeating unit having an acid-decomposable group (hereinafter also referred to as "repeating unit A").
The acid-decomposable group preferably includes a structure in which a polar group is protected by a group that decomposes and leaves by the action of an acid (leaving group).
Polar groups include carboxy groups, phenolic hydroxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamide groups, sulfonylimide groups, (alkylsulfonyl)(alkylcarbonyl)methylene groups, and (alkylsulfonyl)(alkylcarbonyl)imide groups. , bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris(alkylcarbonyl)methylene group, tris(alkylsulfonyl)methylene group, etc. (a group that dissociates in a 2.38% by mass tetramethylammonium hydroxide aqueous solution), an alcoholic hydroxyl group, and the like.

The alcoholic hydroxyl group is a hydroxyl group bonded to a hydrocarbon group, and refers to a hydroxyl group other than a hydroxyl group directly bonded to an aromatic ring (phenolic hydroxyl group). It excludes aliphatic alcohols substituted with functional groups (eg, hexafluoroisopropanol groups, etc.). As the alcoholic hydroxyl group, a hydroxyl group having a pKa (acid dissociation constant) of 12 to 20 is preferable.

The polar group is preferably a carboxy group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

Preferred groups as acid-decomposable groups are groups in which the hydrogen atoms of these groups are substituted with groups (leaving groups) that leave under the action of acid.
Examples of groups that leave by the action of an acid (leaving groups) include -C(R ₃₆ )(R ₃₇ )(R ₃₈ ), -C(R ₃₆ )(R ₃₇ )(OR ₃₉ ), and - C(R ₀₁ ) (R ₀₂ ) (OR ₃₉ ) and the like.
In the formula, R ₃₆ to R ₃₉ each independently represent an alkyl group, cycloalkyl group, aryl group, aralkyl group or alkenyl group. R ₃₆ and R ₃₇ may combine with each other to form a ring.
R ₀₁ and R ₀₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

The alkyl groups of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ are preferably alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, n-butyl, sec-butyl, hexyl. groups, and octyl groups.
The cycloalkyl groups of R ₃₆ -R ₃₉ , R ₀₁ and R ₀₂ may be monocyclic or polycyclic. The monocyclic ring is preferably a cycloalkyl group having 3 to 8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl and the like. The polycyclic ring is preferably a cycloalkyl group having 6 to 20 carbon atoms, such as adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetracyclododecyl group. , and androstanyl group. One or more carbon atoms in the cycloalkyl group may be substituted with a heteroatom such as an oxygen atom.
The aryl groups of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ are preferably aryl groups having 6 to 10 carbon atoms, such as phenyl, naphthyl and anthryl groups.
Aralkyl groups represented by R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ are preferably aralkyl groups having 7 to 12 carbon atoms, such as benzyl, phenethyl and naphthylmethyl groups.
Alkenyl groups represented by R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ are preferably alkenyl groups having 2 to 8 carbon atoms, such as vinyl, allyl, butenyl and cyclohexenyl groups.
The ring formed by combining R ₃₆ and R ₃₇ is preferably a cycloalkyl group (monocyclic or polycyclic). The monocyclic cycloalkyl group is preferably a cyclopentyl group, cyclohexyl group, or the like, and the polycyclic cycloalkyl group is preferably a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, or the like.

The acid-decomposable group is preferably a tertiary alkyl ester group, an acetal group, a cumyl ester group, an enol ester group, or an acetal ester group, more preferably an acetal group or a tertiary alkyl ester group.

Resin (A) preferably contains, as repeating unit A, a repeating unit represented by the following general formula (AI).

In general formula (AI), T represents a single bond or a divalent linking group.
Examples of the divalent linking group for T include an alkylene group, an arylene group, -COO-Rt-, and -O-Rt-. In the formula, Rt represents an alkylene group, a cycloalkylene group, or an arylene group.
T is preferably a single bond or -COO-Rt-. Rt is preferably a chain alkylene group having 1 to 5 carbon atoms, more preferably -CH ₂ -, -(CH ₂ ) ₂ -, or -(CH ₂ ) ₃ -.
More preferably T is a single bond.

In general formula (AI), Xa ₁ represents a hydrogen atom, a halogen atom, or a monovalent organic group.
Xa ₁ is preferably a hydrogen atom or an alkyl group.
The alkyl group of Xa ₁ may have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom (preferably a fluorine atom).
The alkyl group of Xa ₁ preferably has 1 to 4 carbon atoms, and examples thereof include methyl, ethyl, propyl, hydroxymethyl and trifluoromethyl groups. The alkyl group of Xa ₁ is preferably a methyl group.

In general formula (AI), Rx ₁ to Rx ₃ each independently represent an alkyl group or a cycloalkyl group.
Any two of Rx ₁ to Rx ₃ may or may not combine to form a ring structure.
The alkyl groups of Rx ₁ , Rx ₂ and Rx ₃ may be linear or branched, and include methyl, ethyl, n-propyl, isopropyl and n-butyl groups. , isobutyl group, t-butyl group and the like are preferred. The number of carbon atoms in the alkyl group is preferably 1-10, more preferably 1-5, and even more preferably 1-3. Some of the carbon-carbon bonds in the alkyl groups of Rx ₁ , Rx ₂ and Rx ₃ may be double bonds.
The cycloalkyl groups of Rx ₁ , Rx ₂ and Rx ₃ may be monocyclic or polycyclic. A cyclopentyl group, a cyclohexyl group, etc. are mentioned as a monocyclic cycloalkyl group. Polycyclic cycloalkyl groups include norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups.

The ring formed by combining two of Rx ₁ , Rx ₂ and Rx ₃ may be monocyclic or polycyclic. Examples of monocyclic rings include monocyclic cycloalkane rings such as cyclopentyl ring, cyclohexyl ring, cycloheptyl ring, and cyclooctane ring. Examples of polycyclic rings include polycyclic cycloalkyl rings such as norbornane, tetracyclodecane, tetracyclododecane, and adamantane rings. Among them, a cyclopentyl ring, a cyclohexyl ring, or an adamantane ring is preferable.
As the ring formed by combining two of Rx ₁ , Rx ₂ and Rx ₃ , the rings shown below are also preferable.

Specific examples of the monomer corresponding to the repeating unit represented by formula (AI) are given below. The following specific examples correspond to the case where Xa ₁ in general formula (AI) is a methyl group, and Xa ₁ can optionally be substituted with a hydrogen atom, a halogen atom, or a monovalent organic group.

Resin (A) also preferably has, as repeating unit A, a repeating unit described in paragraphs [0336] to [0369] of US Patent Application Publication No. 2016/0070167A1.

In addition, the resin (A) contains, as the repeating unit A, a group that is decomposed by the action of an acid described in paragraphs [0363] to [0364] of US Patent Application Publication No. 2016/0070167A1 to generate an alcoholic hydroxyl group. You may have a repeating unit containing.

The resin (A) may contain the repeating unit A singly or in combination of two or more.

The content of the repeating unit A contained in the resin (A) (the total if there are multiple repeating units A) is preferably 10 to 90 mol%, preferably 20 to 90 mol%, based on the total repeating units of the resin (A). 80 mol % is more preferred, 30 to 80 mol % is even more preferred, and 35 to 80 mol % is particularly preferred.

- A repeating unit having at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure. The resin (A) contains a structure selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure. Specifically, it is more preferable to include a repeating unit (hereinafter also referred to as “repeating unit B”) having at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure.
Among others, the resin (A) preferably contains one or more of a sultone structure and a carbonate structure in terms of further suppressing bridging defects in the formed pattern. It is more preferable to include at least one of a unit and a repeating unit having a carbonate structure.

The lactone structure or sultone structure may have a lactone ring or a sultone ring, and a lactone structure having a 5- to 7-membered lactone ring or a sultone structure having a 5- to 7-membered sultone ring is preferred.
A lactone structure in which a 5- to 7-membered lactone ring is condensed with another ring to form a bicyclo structure or a spiro structure is also preferred. A sultone structure in which a 5- to 7-membered sultone ring is condensed with another ring to form a bicyclo structure or a spiro structure is also preferred.

Among them, the resin (A) has a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-22), or any of the following general formulas (SL1-1) to (SL1-3). It preferably contains a repeating unit having a sultone structure represented by Also, the lactone structure or sultone structure may be directly bonded to the main chain.
Among them, general formula (LC1-1), general formula (LC1-4), general formula (LC1-5), general formula (LC1-8), general formula (LC1-16), general formula (LC1-21) Alternatively, a lactone structure represented by general formula (LC1-22) or a sultone structure represented by general formula (SL1-1) is preferred.

The lactone structure or sultone structure may or may not have a substituent (Rb ₂ ). The substituent (Rb ₂ ) includes an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxy group, A halogen atom, a hydroxyl group, a cyano group, or the like is preferable, and an alkyl group having 1 to 4 carbon atoms or a cyano group is more preferable. _n2 represents an integer from 0 to 4; When n ₂ is 2 or more, the multiple substituents (Rb ₂ ) may be the same or different. Also, a plurality of substituents (Rb ₂ ) may be bonded to each other to form a ring.

As the repeating unit having a lactone structure or sultone structure, a repeating unit represented by the following general formula (III) is preferable.

In the above general formula (III),
A represents -COO- or -CONH-.

n is the number of repetitions of the structure represented by -R ₀ -Z- and represents an integer of 0 to 5, preferably 0 or 1, more preferably 0; When n is 0, (-R ₀ -Z-)n becomes a single bond.

R ₀ represents an alkylene group, a cycloalkylene group, or a combination thereof. When multiple R ₀ are present, the multiple R ₀ may be the same or different.
The alkylene group represented by R ₀ may be linear or branched. The number of carbon atoms in the alkylene group represented by R ₀ is, for example, 1 to 12, preferably 1 to 10, more preferably 1 to 6.
The cycloalkylene group represented by R ₀ may be either monocyclic or polycyclic. The number of carbon atoms in the cycloalkylene group represented by R ₀ is, for example, 1 to 12, preferably 1 to 10, more preferably 1 to 6. Cycloalkanes constituting the cycloalkylene group represented by R ₀ include monocyclic cycloalkane rings such as cyclopentane ring, cyclohexane ring, cycloheptane ring, and cyclooctane ring, norbornane ring, and tetracyclodecane ring. , tetracyclododecane ring, and polycyclic cycloalkane ring such as adamantane ring.
The alkylene group or cycloalkylene group of R ₀ may have a substituent. Although the substituent is not particularly limited, for example, an alkyl group having 1 to 8 carbon atoms (either linear or branched), a cycloalkyl group having 4 to 7 carbon atoms (monocyclic and polycyclic any group), an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxy group, a halogen atom, a hydroxyl group, a cyano group, and the like.

Z represents a single bond, -O-, -COO-, -CONH-, -NH-CO-O-, or -NH-CO-NH-. When there are multiple Z's, the multiple Z's may be the same or different.
Among them, Z is preferably -O- or -COO-, more preferably -COO-.

_R8 represents a monovalent organic group having a lactone structure or a sultone structure.
Among them, in any of the structures represented by general formulas (LC1-1) to (LC1-22) and the structures represented by general formulas (SL1-1) to (SL1-3), a lactone structure or a sultone It is preferably a group obtained by removing one hydrogen atom from one carbon atom constituting the structure. The carbon atoms from which one hydrogen atom is removed are preferably not carbon atoms constituting the substituent (Rb ₂ ).

_R7 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group).
The organic group represented by R ₇ includes, for example, an alkyl group having 1 to 8 carbon atoms (either linear or branched), preferably a methyl group.

Examples of monomers corresponding to repeating units having at least one selected from the group consisting of lactone structures and sultone structures are shown below.
In the examples below, the methyl group attached to the vinyl group may be replaced with a hydrogen atom, a halogen atom, or a monovalent organic group.

Resin (A) may have a repeating unit having a carbonate structure. As the carbonate structure, a cyclic carbonate structure is preferred.
As the repeating unit having a cyclic carbonate structure, a repeating unit represented by the following general formula (A-1) is preferable.

In general formula (A-1), R _A ¹ represents a hydrogen atom, a halogen atom, or a monovalent organic group.
The monovalent organic group represented by R _A ¹ includes an optionally substituted alkyl group having 1 to 6 carbon atoms, preferably a methyl group. A halogen atom, a hydroxyl group, etc. are mentioned as a substituent.
n represents an integer of 0 or more.
R _A ² represents a substituent. When n is 2 or more, a plurality of R _A ² may be the same or different. Although the substituent is not particularly limited, for example, an alkyl group having 1 to 8 carbon atoms (either linear or branched), a cycloalkyl group having 4 to 7 carbon atoms (monocyclic and polycyclic any group), an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxy group, a halogen atom, a hydroxyl group, a cyano group, and the like.
A represents a single bond or a divalent linking group.
The divalent linking group represented by A is not particularly limited, but examples include -CO-, -O-, -S-, -SO-, -SO ₂ -, -NH-, alkylene groups (preferably carbon 1 to 6), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), and a divalent linking group combining a plurality of these. Among these, an alkylene group (preferably having 1 to 6 carbon atoms) which may contain -CO- and -O- is more preferred.
Z represents an atomic group forming a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula. Z is preferably an atomic group forming a monocyclic ring together with the group represented by —O—CO—O— in the formula, and the number of ring members of the monocyclic ring is preferably 5 to 6, more preferably 5.

Resin (A) also preferably has, as repeating unit B, a repeating unit described in paragraphs [0370] to [0414] of US Patent Application Publication No. 2016/0070167A1.

The repeating unit B may be contained singly or in combination of two or more.

The content of the repeating unit B contained in the resin (A) (the total when there are multiple repeating units B) is preferably 5 to 70 mol%, 10 ~65 mol% is more preferred, 20 to 65 mol% is even more preferred, and 20 to 60 mol% is particularly preferred.
Among them, the content of the repeating unit having a sultone structure and the repeating unit having a carbonate structure contained in the resin (A) (the total content when there are multiple repeating units) is 10 to 65 mol % is more preferred, 10 to 60 mol % is even more preferred, and 10 to 55 mol % is particularly preferred.

• Repeating unit having a polar group The resin (A) preferably contains a repeating unit having a polar group (hereinafter also referred to as "repeating unit C").
Polar groups include hydroxyl groups, cyano groups, carboxy groups, and fluorinated alcohol groups (eg, hexafluoroisopropanol groups).
As the repeating unit C, a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group is preferred. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a polar group is preferably a cyclohexyl group, an adamantyl group, or a norbornane group.

Specific examples of the monomer corresponding to the repeating unit C are shown below, but the present invention is not limited to these specific examples.

In addition, specific examples of repeating unit C include repeating units disclosed in paragraphs [0415] to [0433] of US Patent Application Publication No. 2016/0070167A1.
The resin (A) may contain the repeating unit C singly or in combination of two or more.

When the resin (A) contains the repeating unit C, the content of the repeating unit C (the total when there are multiple repeating units C) is 5 to 60 mol with respect to all repeating units in the resin (A). %, more preferably 5 to 30 mol %, even more preferably 5 to 15 mol %.

-Repeating unit having neither an acid-decomposable group nor a polar group The resin (A) further includes a repeating unit having neither an acid-decomposable group nor a polar group (hereinafter also referred to as "repeating unit D". ) may be included.
The repeating unit D preferably has an alicyclic hydrocarbon structure. Examples of the repeating unit D include repeating units described in paragraphs [0236] to [0237] of US Patent Application Publication No. 2016/0026083A1.
Preferred examples of the monomer corresponding to the repeating unit D are shown below.

In addition, specific examples of the repeating unit D include repeating units disclosed in paragraph [0433] of US Patent Application Publication No. 2016/0070167A1.
The resin (A) may contain the repeating unit D singly or in combination of two or more.
When the resin (A) contains the repeating unit D, the content of the repeating unit D (the total when there are multiple repeating units D) is 5 to 40 mol with respect to all repeating units in the resin (A). %, more preferably 5 to 30 mol %, still more preferably 5 to 25 mol %, particularly preferably 5 to 15 mol %.

In addition to the above-described repeating units, the resin (A) may include, as other repeating units, dry etching resistance, standard developer suitability, substrate adhesion, resist profile, or resolution, which is a generally required property of a resist. It may have various repeating units for the purpose of adjusting , heat resistance, sensitivity, and the like.
Such repeating units include, but are not limited to, repeating units corresponding to a given monomer.

The predetermined monomer has one addition-polymerizable unsaturated bond selected from, for example, acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, and vinyl esters. compounds and the like.
In addition, addition-polymerizable unsaturated compounds that are copolymerizable with the monomers corresponding to the above-mentioned various repeating units may be used.
In the resin (A), the content molar ratio of each repeating unit is appropriately set in order to adjust various performances.

The resin (A) preferably contains a repeating unit derived from at least one of acrylic acid ester and methacrylic acid ester. When the resin (A), which is an acid-decomposable resin, has a structure containing repeating units derived from at least one of an acrylic acid ester and a methacrylic acid ester, by-products produced during the production process include supermolecular weights and gel components. can contain many. Therefore, when the resin (A), which is an acid-decomposable resin, has a structure containing a repeating unit derived from at least one of an acrylic acid ester and a methacrylic acid ester, the effect of the production method of the present invention is more excellent. can enjoy

When the polymer solution is used for ArF exposure, the repeating unit having an aromatic group preferably accounts for 15 mol% or less of all repeating units in the resin (A), from the viewpoint of ArF light transmission. , 10 mol % or less.

When the polymer solution is for ArF exposure, the resin (A) preferably comprises (meth)acrylate repeating units in all repeating units. In other words, the resin (A) is preferably a resin composed of repeating units derived from at least one of acrylic acid ester and methacrylic acid ester. In this case, all repeating units may be methacrylate repeating units, all repeating units may be acrylate repeating units, or all repeating units may be methacrylate repeating units and acrylate repeating units. Although it can be used, it is preferable that the acrylate-based repeating unit is 50 mol % or less based on the total repeating units of the resin (A).

When the polymer solution is for KrF exposure, EB exposure, or EUV exposure, the resin (A) preferably has a repeating unit having an aromatic hydrocarbon ring group, a repeating unit having a phenolic hydroxyl group, or It is more preferable to include a repeating unit having a structure (acid-decomposable group) in which a phenolic hydroxyl group is protected by a leaving group that decomposes and leaves under the action of an acid. Repeating units containing a phenolic hydroxyl group include hydroxystyrene repeating units and hydroxystyrene (meth)acrylate repeating units.
When the polymer solution is for KrF exposure, EB exposure, or EUV exposure, the content of repeating units having an aromatic hydrocarbon ring group contained in resin (A) is 30 mol % or more is preferable with respect to the unit. Although the upper limit is not particularly limited, it is, for example, 100 mol % or less. Among them, 30 to 100 mol % is preferable, 40 to 100 mol % is more preferable, and 50 to 100 mol % is even more preferable.

In addition, as resin (A), the thing of international publication 2017/057253 etc. can also be used suitably, for example.

The weight average molecular weight of the resin (A) is preferably 1,000 to 200,000, more preferably 2,000 to 20,000, even more preferably 3,000 to 20,000. The dispersity (Mw/Mn) is usually 1.0 to 3.0, preferably 1.0 to 2.6, more preferably 1.0 to 2.0, further preferably 1.1 to 2.0. preferable.

(solvent)
The polymer solution contains a solvent.
As the solvent, a known resist solvent can be appropriately used. For example, paragraphs [0665]-[0670] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0210]-[0235] of US Patent Application Publication No. 2015/0004544A1, US Patent Application Publication No. 2016/0237190A1 Known solvents disclosed in paragraphs [0424] to [0426] of the specification and paragraphs [0357] to [0366] of US Patent Application Publication No. 2016/0274458A1 can be suitably used.
Examples of the solvent include alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate, alkyl alkoxypropionate, cyclic lactone (preferably having 4 to 10 carbon atoms), monoketone compound which may have a ring. (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates. Preferred are alkylene glycol monoalkyl ether carboxylates, and more preferred is propylene glycol monomethyl ether acetate.
As the organic solvent, one kind may be used alone, or two or more kinds may be used in combination, but it is preferable to use one kind alone. When using a mixed solvent in which two or more organic solvents are used in combination, a mixed solvent obtained by mixing a solvent having a hydroxyl group in its structure with a solvent having no hydroxyl group is preferable.

The solid content concentration of the polymer solution is preferably 1.0 to 50% by mass, more preferably 2.0 to 40% by mass, and even more preferably 5.0 to 30% by mass. The solid content concentration is the mass percentage of the mass of the components excluding the solvent with respect to the total mass of the polymer solution.

[Step B]
In step B, a compound (photoacid generator) that generates an acid upon exposure to actinic rays or radiation is added to the polymer solution that has undergone step A to form an actinic ray-sensitive or radiation-sensitive resin composition (hereinafter referred to as "resist (also referred to as "composition").
First, the actinic ray-sensitive or radiation-sensitive resin composition obtained through the step B will be described below.

<Acid-decomposable resin (resin (A))>
The resist composition contains an acid-decomposable resin (resin (A)) derived from the polymer solution described above. The acid-decomposable resin (resin (A)) is as described above.

Resin (A) may be used individually by 1 type, and may use 2 or more types together.
In the resist composition, the content of the resin (A) is generally 20.0% by mass or more, preferably 40.0% by mass or more, and 60.0% by mass, based on the total solid content. The above is more preferable, and 70.0% by mass or more is even more preferable. Although the upper limit is not particularly limited, it is preferably 99.5% by mass or less, more preferably 99.0% by mass or less, and even more preferably 97.0% by mass or less. The solid content means the components excluding the solvent in the composition, and components other than the solvent are regarded as the solid content even if they are liquid components.

<Photoacid generator (B)>
The resist composition contains a compound that generates an acid upon exposure to actinic rays or radiation (hereinafter also referred to as "photoacid generator (B)").
The photoacid generator (B) referred to here is an acid-generating agent normally used for deprotecting a resin component (deprotecting reaction for an acid-decomposable resin) or for causing a cross-linking reaction of a resin component. drug.
As the photoacid generator (B), a compound that generates an organic acid upon exposure to actinic rays or radiation is preferred. Examples include sulfonium salt compounds, iodonium salt compounds, diazonium salt compounds, phosphonium salt compounds, imidosulfonate compounds, oximesulfonate compounds, diazodisulfone compounds, disulfone compounds, and o-nitrobenzylsulfonate compounds.

As the photoacid generator (B), a known compound that generates an acid upon exposure to actinic rays or radiation can be appropriately selected and used either singly or as a mixture thereof. For example, paragraphs [0125]-[0319] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0086]-[0094] of US Patent Application Publication No. 2015/0004544A1, and US Patent Application Publication No. 2016/ The known compounds disclosed in paragraphs [0323] to [0402] of 0237190A1 can be suitably used as the photoacid generator (B).

As the photoacid generator (B), for example, compounds represented by the following general formula (ZI), general formula (ZII), or general formula (ZIII) are preferred.

In the above general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group.
The number of carbon atoms in the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Also, two of R ₂₀₁ to R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Groups formed by combining two of R ₂₀₁ to R ₂₀₃ include an alkylene group (e.g., butylene group, pentylene group, etc.) and —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —. mentioned.
Z ⁻ represents an anion.

Preferred embodiments of the cation in general formula (ZI) include corresponding groups in compound (ZI-1), compound (ZI-2), compound (ZI-3), and compound (ZI-4) described below. be done.
The photoacid generator (B) may be a compound having a plurality of structures represented by general formula (ZI). For example, at least one of R ₂₀₁ to R ₂₀₃ of the compound represented by general formula (ZI) and at least one of R ₂₀₁ to R ₂₀₃ of another compound represented by general formula (ZI) are single bonds. Alternatively, it may be a compound having a structure bonded via a linking group.

First, compound (ZI-1) will be described.
Compound (ZI-1) is an arylsulfonium compound in which at least one of R ₂₀₁ to R ₂₀₃ in general formula (ZI) is an aryl group, that is, a compound having an arylsulfonium cation.
In the arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be aryl groups, or part of R ₂₀₁ to R ₂₀₃ may be aryl groups and the rest may be alkyl groups or cycloalkyl groups.
Arylsulfonium compounds include, for example, triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

The aryl group contained in the arylsulfonium compound is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, benzothiophene residues, and the like. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group or cycloalkyl group optionally possessed by the arylsulfonium compound is a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or 3 to 15 carbon atoms. is preferred, and examples thereof include methyl, ethyl, propyl, n-butyl, sec-butyl, t-butyl, cyclopropyl, cyclobutyl and cyclohexyl groups.

The aryl group, alkyl group, and cycloalkyl group represented by R ₂₀₁ to R ₂₀₃ are each independently an alkyl group (eg, 1 to 15 carbon atoms), a cycloalkyl group (eg, 3 to 15 carbon atoms), an aryl group. (for example, 6 to 14 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group as a substituent.

Next, compound (ZI-2) will be described.
Compound (ZI-2) is a compound in which R ₂₀₁ to R ₂₀₃ in formula (ZI) each independently represents an organic group having no aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a heteroatom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R ₂₀₁ to R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group or a vinyl group, and a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group or alkoxy A carbonylmethyl group is more preferred, and a linear or branched 2-oxoalkyl group is even more preferred.

The alkyl group and cycloalkyl group represented by R ₂₀₁ to R ₂₀₃ include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl group and pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group and norbornyl group) are preferred.
R ₂₀₁ to R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, 1-5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Next, compound (ZI-3) will be described.
Compound (ZI-3) is a compound represented by the following general formula (ZI-3) and having a phenacylsulfonium salt structure.

In general formula (ZI-3),
R _1c to R _5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, or a hydroxyl group , represents a nitro group, an alkylthio group or an arylthio group.
_R6c and _R7c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group.
R _x and R _y each independently represent an alkyl group, cycloalkyl group, 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxycarbonylalkyl group, allyl group or 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 each combine to form a ring structure. This ring structure may each independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the ring structure include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocyclic rings, and polycyclic condensed rings in which two or more of these rings are combined. The ring structure includes a 3- to 10-membered ring, preferably a 4- to 8-membered ring, and more preferably a 5- or 6-membered ring.

Groups formed by bonding two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.
The group formed by combining R _5c and R _6c and R _5c and R _x is preferably a single bond or an alkylene group. The alkylene group includes a methylene group, an ethylene group, and the like.
^Zc- represents an anion.

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

In general formula (ZI-4),
l represents an integer of 0 to 2;
r represents an integer of 0 to 8;
_R13 represents a group having a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a cycloalkyl group. These groups may have a substituent.
R ₁₄ represents a group having a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a cycloalkyl group. These groups may have a substituent. R ₁₄ each independently represent the above groups such as a hydroxyl group when there are more than one.
Each R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. These groups may have a substituent. Two R ₁₅ may be joined together to form a ring. When two R ₁₅ are combined to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. In one aspect, two R ₁₅ are alkylene groups, preferably joined together to form a ring structure.
Z ⁻ represents an anion.

In general formula (ZI-4), the alkyl groups represented by R ₁₃ , R ₁₄ and R ₁₅ are linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. The alkyl group is preferably a methyl group, an ethyl group, an n-butyl group, or a t-butyl group.

Next, general formulas (ZII) and (ZIII) will be described.
In general formulas (ZII) and (ZIII), R ₂₀₄ to R ₂₀₇ each independently represent an aryl group, an alkyl group or a cycloalkyl group.
The aryl group represented by R ₂₀₄ to R ₂₀₇ is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group represented by R ₂₀₄ to R ₂₀₇ may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Skeletons of aryl groups having a heterocyclic structure include, for example, pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
Alkyl groups and cycloalkyl groups represented by R ₂₀₄ to R ₂₀₇ include linear alkyl groups having 1 to 10 carbon atoms and branched alkyl groups having 3 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, pentyl group, etc.) or a cycloalkyl group having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group, norbornyl group, etc.) is preferable.

The aryl group, alkyl group and cycloalkyl group represented by R ₂₀₄ to R ₂₀₇ may each independently have a substituent. Examples of substituents that the aryl group, alkyl group and cycloalkyl group represented by R ₂₀₄ to R ₂₀₇ may have include an alkyl group (eg, 1 to 15 carbon atoms) and a cycloalkyl group (eg, carbon 3 to 15), aryl groups (eg, 6 to 15 carbon atoms), alkoxy groups (eg, 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups.
Z ⁻ represents an anion.

Z - in general formula (ZI), Z ^- in general formula (ZII ^{), Zc - in} general formula (ZI-3), and Z ^- in general formula (ZI-4) are represented by the following general formula (3) The anions represented are preferred.

In general formula (3),
o represents an integer of 1 to 3; p represents an integer from 0 to 10; q represents an integer from 0 to 10;

Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1-10, more preferably 1-4. A perfluoroalkyl group is preferable as the alkyl group substituted with at least one fluorine atom.
Xf is preferably a fluorine atom or a C 1-4 perfluoroalkyl group, more preferably a fluorine atom or CF ₃ . In particular, it is more preferable that both Xf are fluorine atoms.

_R4 and _R5 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. When multiple R ₄ and R ₅ are present, each of R ₄ and R ₅ may be the same or different.
The alkyl groups represented by R ₄ and R ₅ may have substituents and preferably have 1 to 4 carbon atoms. R ₄ and R ₅ are preferably hydrogen atoms.
Specific examples and preferred aspects of the alkyl group substituted with at least one fluorine atom are the same as the specific examples and preferred aspects of Xf in general formula (3).

L represents a divalent linking group. When there are multiple L's, each L may be the same or different.
Examples of divalent linking groups include -COO-(-C(=O)-O-), -OCO-, -CONH-, -NHCO-, -CO-, -O-, -S-, - SO—, —SO ₂ —, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), and a plurality of these A combined divalent linking group and the like can be mentioned. Among these, -COO-, -OCO-, -CONH-, -NHCO-, -CO-, -O-, -SO ₂ -, -COO-alkylene group-, -OCO-alkylene group-, -CONH- An alkylene group - or -NHCO-alkylene group- is preferred, and -COO-, -OCO-, -CONH-, -SO ₂ -, -COO-alkylene group- or -OCO-alkylene group- is more preferred.

W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferable.
Cyclic organic groups include, for example, alicyclic groups, aryl groups, and heterocyclic groups.
Alicyclic groups may be monocyclic or polycyclic. Monocyclic alicyclic groups include, for example, monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of polycyclic alicyclic groups include polycyclic cycloalkyl groups such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. Among them, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups, are preferred.

Aryl groups may be monocyclic or polycyclic. The aryl group includes, for example, phenyl group, naphthyl group, phenanthryl group, and anthryl group.
A heterocyclic group may be monocyclic or polycyclic. The polycyclic type can further suppress acid diffusion. Moreover, the heterocyclic group may or may not have aromaticity. Heterocyclic rings having aromaticity include, for example, furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Non-aromatic heterocycles include, for example, a tetrahydropyran ring, a lactone ring, a sultone ring, and a decahydroisoquinoline ring. Examples of the lactone ring and sultone ring include the lactone structure and sultone structure exemplified in the resins described above. The heterocyclic ring in the heterocyclic group is particularly preferably a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring.

The cyclic organic group may have a substituent. Examples of this substituent include alkyl groups (either linear or branched, preferably having 1 to 12 carbon atoms), cycloalkyl groups (monocyclic, polycyclic, and spirocyclic). any group, preferably having 3 to 20 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), hydroxyl group, alkoxy group, ester group, amide group, urethane group, ureido group, thioether group, sulfonamide groups, and sulfonate ester groups. In addition, carbonyl carbon may be sufficient as carbon (carbon which contributes to ring formation) which comprises a cyclic|annular organic group.

Examples of anions represented by the general formula (3) include SO ₃ ⁻ —CF ₂ —CH ₂ —OCO-(L)q′-W, SO ₃ ^— —CF ₂ —CHF—CH ₂ —OCO-(L) q′-W, SO ₃ ⁻ —CF ₂ —COO-(L)q′-W, SO ₃ ^— —CF ₂ —CF ₂ —CH ₂ —CH ₂ —(L)qW, or SO ₃ ^— -CF ₂ -CH(CF ₃ )-OCO-(L)q'-W is preferred. Here, L, q and W are the same as in general formula (3). q' represents an integer from 0 to 10;

In one embodiment, Z ^- in general formula (ZI), Z - in general formula (ZII), ^{Zc - in} general formula (ZI-3), and Z ^- in general formula (ZI-4) are the following general Anions of formula (4) are also preferred.

In general formula (4),
X ^B1 and X ^B2 each independently represent a hydrogen atom or a monovalent organic group having no fluorine atom. X ^B1 and X ^B2 are preferably hydrogen atoms.
X ^B3 and X ^B4 each independently represent a hydrogen atom or a monovalent organic group. At least one of X ^B3 and X ^B4 is preferably a fluorine atom or a monovalent organic group having a fluorine atom, and both X ^B3 and X ^B4 are a fluorine atom or a monovalent organic group having a fluorine atom is more preferred. More preferably, both X ^B3 and X ^B4 are fluorine-substituted alkyl groups.
L, q and W are the same as in general formula (3).

Z ^- in general formula (ZI), Z - in general formula (ZII ^{), Zc - in} general formula (ZI-3), and Z ^- in general formula (ZI-4) are represented by the following general formula (5) The anions represented are preferred.

In general formula (5), each Xa independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. Each Xb independently represents a hydrogen atom or an organic group having no fluorine atom. The definitions and preferred embodiments of o, p, q, R ₄ , R ₅ , L, and W are the same as in general formula (3).

Z ^- in general formula (ZI), Z ^- in general formula (ZII), Zc ^- in general formula (ZI-3), and Z ^- in general formula (ZI-4) are benzenesulfonate anions. Often preferred is a benzenesulfonate anion substituted by a branched alkyl group or a cycloalkyl group.

Z ^- in general formula (ZI), Z - in general formula (ZII ^{), Zc - in} general formula (ZI-3), and Z ^- in general formula (ZI-4) are represented by the following general formula (SA1) An aromatic sulfonate anion represented by is also preferred.

In formula (SA1),
Ar represents an aryl group and may further have a substituent other than the sulfonate anion and -(D-B) group. Substituents which may be further included include a fluorine atom and a hydroxyl group.

n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and still more preferably 3.

D represents a single bond or a divalent linking group. Examples of divalent linking groups include ether groups, thioether groups, carbonyl groups, sulfoxide groups, sulfone groups, sulfonate ester groups, ester groups, and groups consisting of combinations of two or more thereof.

B represents a hydrocarbon group.

D is preferably a single bond and B is an aliphatic hydrocarbon structure. B is more preferably an isopropyl group or a cyclohexyl group.

Preferred examples of the sulfonium cation in general formula (ZI) and the iodonium cation in general formula (ZII) are shown below.

Preferable examples of the anion Z ⁻ in general formula (ZI), the anion Z ⁻ in general formula (ZII), Zc ⁻ in general formula (ZI-3), and Z ⁻ in general formula (ZI-4) are shown below.

Any combination of the above cations and anions can be used as the photoacid generator (B).

The photoacid generator (B) may be in the form of a low-molecular-weight compound, or may be in the form of being incorporated into a part of the polymer. Moreover, the form of a low-molecular-weight compound and the form incorporated into a part of a polymer may be used in combination.
The photoacid generator (B) is preferably in the form of a low molecular weight compound.
When the photoacid generator (B) is in the form of a low-molecular-weight compound, the molecular weight is preferably 3,000 or less, more preferably 2,000 or less, even more preferably 1,000 or less.
When the photoacid generator (B) is in the form of being incorporated into a part of the polymer, it may be incorporated into a part of the resin (A) described above, or may be incorporated into a resin different from the resin (A). may
The photoacid generator (B) may be used alone or in combination of two or more.
In the resist composition, the content of the photoacid generator (B) (the total when multiple types are present) is preferably 0.1 to 35.0% by mass, based on the total solid content of the composition, and 0 .5 to 25.0% by mass is more preferable, and 3.0 to 20.0% by mass is even more preferable.
When the compound represented by the general formula (ZI-3) or (ZI-4) is included as a photoacid generator, the content of the photoacid generator contained in the resist composition (if multiple types are present, The total) is preferably 5 to 35% by mass, more preferably 7 to 30% by mass, based on the total solid content of the composition.

The acid dissociation constant pKa of the acid generated by decomposition of the photoacid generator (B) upon exposure to actinic rays or radiation is, for example, -0.01 or less, preferably -1.00 or less. -1.50 or less is more preferable, and -2.00 or less is even more preferable. Although the lower limit of pKa is not particularly limited, it is -5.00 or more, for example. pKa can be measured by the method described above.

<Acid diffusion control agent (C)>
The resist composition preferably contains an acid diffusion controller as long as the effects of the present invention are not impaired.
The acid diffusion control agent (C) traps the acid generated from the acid generator or the like during exposure, and acts as a quencher that suppresses the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid. . Examples of the acid diffusion control agent (C) include a basic compound (CA), a basic compound (CB) whose basicity is reduced or lost by irradiation with actinic rays or radiation, and a relatively weak acid with respect to the acid generator. onium salt (CC), a low-molecular-weight compound (CD) that has a nitrogen atom and a group that can be eliminated by the action of an acid, or an onium salt compound (CE) that has a nitrogen atom in the cation portion, etc. to control acid diffusion. Can be used as an agent. A known acid diffusion control agent can be appropriately used in the resist composition. For example, paragraphs [0627] to [0664] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0095] to [0187] of US Patent Application Publication No. 2015/0004544A1, US 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 are suitable as the acid diffusion control agent (C) can be used for

As the basic compound (CA), compounds having structures represented by the following formulas (A) to (E) are preferred.

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl represents a group (6 to 20 carbon atoms). R ²⁰¹ and R ²⁰² may combine 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 general formulas (A) and (E) may be substituted or unsubstituted.
Regarding the above alkyl group, the substituted alkyl group is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.
The alkyl groups in general formulas (A) and (E) are more preferably unsubstituted.

As the basic compound (CA), guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, or piperidine is preferable, and imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, A compound having a trialkylamine 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 preferred.

A basic compound (CB) whose basicity is reduced or lost by irradiation with actinic rays or radiation (hereinafter also referred to as "compound (CB)") has a proton acceptor functional group, and actinic rays or It is a compound whose proton acceptor property is reduced or lost, or whose proton acceptor property is changed to acidic by being decomposed by irradiation with radiation.

The proton-accepting functional group is a functional group having electrons or a group capable of electrostatically interacting with protons, for example, a functional group having a macrocyclic structure such as cyclic polyether, or a π-conjugated means a functional group having a nitrogen atom with a lone pair of electrons that does not contribute to A nitrogen atom having a lone pair of electrons that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure represented by the following formula.

Preferred partial structures of proton acceptor functional groups include, for example, crown ether structures, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures.

The compound (CB) is decomposed by exposure to actinic rays or radiation to reduce or eliminate the proton acceptor property, or to generate a compound whose proton acceptor property is changed to an acidic one. Here, the reduction or disappearance of proton acceptor property, or the change from proton acceptor property to acidity is a change in proton acceptor property due to the addition of protons to the proton acceptor functional group. means that when a proton adduct is produced from the compound (CB) having a proton acceptor functional group and protons, the equilibrium constant in the chemical equilibrium decreases.
Proton acceptor property can be confirmed by performing pH measurement.

The acid dissociation constant pKa of the compound generated by decomposition of the compound (CB) by irradiation with actinic rays or radiation preferably satisfies pKa<−1, more preferably satisfies −13<pKa<−1, and − More preferably, 13<pKa<-3 is satisfied.

The acid dissociation constant pKa can be determined by the method described above.

Onium salts (CC), which are relatively weak acids relative to acid generators, can be used as acid diffusion control agents in resist compositions.
When an acid generator and an onium salt that generates an acid that is relatively weak acid relative to the acid generated from the acid generator are mixed and used, the acid generated from the acid generator by actinic rays or irradiation of radiation When an acid collides with an onium salt with an unreacted weak acid anion, salt exchange releases the weak acid to yield an onium salt with a strong acid anion. In this process, the strong acid is exchanged for a weak acid with a lower catalytic activity, so that the acid is apparently deactivated and acid diffusion can be controlled.

As the onium salt which becomes a relatively weak acid relative to the acid generator, compounds represented by the following general formulas (d1-1) to (d1-3) are preferred.

In the formula, R ⁵¹ is an optionally substituted hydrocarbon group, and Z ^2c is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms (provided that the carbon is not substituted with a fluorine atom), R ⁵² is an organic group, Y ³ is a linear, branched or cyclic alkylene group or arylene group, and Rf is a fluorine atom Each M ⁺ is independently an ammonium cation, a sulfonium cation, or an iodonium cation.

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

An onium salt (CC), which is a relatively weak acid with respect to an acid generator, is a compound ( Hereinafter, it may also be referred to as a “compound (CCA)”).
The compound (CCA) is preferably a compound represented by any one of the following general formulas (C-1) to (C-3).

In general formulas (C-1) to (C-3),
R ₁ , R ₂ and R ₃ each independently represent a substituent having 1 or more carbon atoms.
L ₁ represents a divalent linking group or a single bond that links the cation site and the anion site.
—X ^— represents an anionic moiety selected from —COO ⁻ , —SO ₃ ⁻ , —SO ₂ ⁻ , and —N ⁻ —R ₄ . R ₄ has a carbonyl group (-C(=O)-), a sulfonyl group (-S(=O) ₂ -), and a sulfinyl group (-S(=O)- ) represents a monovalent substituent having at least one of
R ₁ , R ₂ , R ₃ , R ₄ and L ₁ may combine with each other to form a ring structure. In general formula (C-3), two of R ₁ to R ₃ together represent one divalent substituent, which may be bonded to the N atom via a double bond.

Examples of substituents having 1 or more carbon atoms for R ₁ to R ₃ include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, and a cycloalkylamino A carbonyl group, an arylaminocarbonyl group, and the like can be mentioned. Among them, an alkyl group, a cycloalkyl group, or an aryl group is preferable.

L ₁ as a divalent linking group is a linear or branched alkylene group, a cycloalkylene group, an arylene group, a carbonyl group, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, and two of these A group formed by combining the above and the like can be mentioned. L ₁ is preferably an alkylene group, an arylene group, an ether bond, an ester bond, or a group formed by combining two or more of these.

A low-molecular-weight compound (CD) having a nitrogen atom and a group that leaves under the action of an acid (hereinafter also referred to as "compound (CD)") has a group that leaves under the action of an acid on the nitrogen atom. It is preferably an amine derivative having
The group that leaves by the action of an acid is preferably an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a hemiaminal ether group, more preferably a carbamate group or a hemiaminal ether group. .
The molecular weight of the compound (CD) is preferably 100-1000, more preferably 100-700, even more preferably 100-500.
Compound (CD) may have a carbamate group with a protecting group on the nitrogen atom. A protecting group constituting a carbamate group is represented by the following general formula (d-1).

In general formula (d-1),
Rb each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 3 to 30 carbon atoms), an aryl group (preferably having 3 to 30 carbon atoms), an aralkyl group ( preferably 1 to 10 carbon atoms) or an alkoxyalkyl group (preferably 1 to 10 carbon atoms). Rb's may be linked together to form a ring.
The alkyl group, cycloalkyl group, aryl group and aralkyl group represented by Rb are each independently a hydroxyl group, a cyano group, an amino group, a pyrrolidino group, a piperidino group, a morpholino group, a functional group such as an oxo group, an alkoxy group, or a halogen Atoms may be substituted. The same applies to the alkoxyalkyl group represented by Rb.

Rb is preferably a linear or branched alkyl group, cycloalkyl group or aryl group, more preferably a linear or branched alkyl group or cycloalkyl group.
Examples of the ring formed by connecting two Rb's to each other include alicyclic hydrocarbons, aromatic hydrocarbons, heterocyclic hydrocarbons, derivatives thereof, and the like.
Specific structures of the group represented by formula (d-1) include, but are not limited to, structures disclosed in paragraph [0466] of US Patent Publication No. US2012/0135348A1.

Compound (CD) preferably has a structure represented by the following general formula (6).

In 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 Ra's may be the same or different, and the two Ra's may be linked together to form a heterocyclic ring together with the nitrogen atom in the formula. This heterocyclic ring may contain a heteroatom other than the nitrogen atom in the formula.
Rb has the same definition as Rb in formula (d-1) above, and preferred examples are also the same.
In the general formula (6), the alkyl group, cycloalkyl group, aryl group and aralkyl group as Ra are each independently substituted with an alkyl group, cycloalkyl group, aryl group and aralkyl group as Rb. It may be substituted with the same groups as the groups described above as good groups.

Specific examples of the alkyl group, cycloalkyl group, aryl group, and aralkyl group (these groups may be substituted with the above groups) for Ra include the same groups as the specific examples described above for Rb. be done.
Specific examples of particularly preferred compounds (CD) in the present invention include, but are not limited to, compounds disclosed in paragraph [0475] of US Patent Application Publication No. 2012/0135348A1.

The onium salt compound (CE) having a nitrogen atom in the cation moiety (hereinafter also referred to as "compound (CE)") is preferably a compound having a basic site containing a nitrogen atom in the cation moiety. The basic moiety is preferably an amino group, more preferably an aliphatic amino group. More preferably all of the atoms adjacent to the nitrogen atom in the basic moiety are hydrogen atoms or carbon atoms. Moreover, from the viewpoint of improving basicity, it is preferable that an electron-withdrawing functional group (a carbonyl group, a sulfonyl group, a cyano group, a halogen atom, etc.) is not directly connected to the nitrogen atom.
Preferred specific examples of the compound (CE) include, but are not limited to, compounds disclosed in paragraph [0203] of US Patent Application Publication No. 2015/0309408A1.

Preferred examples of the acid diffusion controller (C) are shown below.

In the resist composition, the acid diffusion controller (C) may be used singly or in combination of two or more.
When the resist composition contains the acid diffusion control agent (C), the content of the acid diffusion control agent (C) (when there are multiple types thereof, the total amount) is 0.00% based on the total solid content of the composition. 01 to 10.0% by mass is preferable, and 0.01 to 5.0% by mass is more preferable.

<Hydrophobic resin (D)>
The resist composition may contain a hydrophobic resin (D). The hydrophobic resin (D) is preferably a resin different from the resin (A).
By including the hydrophobic resin (D) in the resist composition, the static/dynamic contact angle on the surface of the actinic ray-sensitive or radiation-sensitive film can be controlled. This makes it possible to improve development characteristics, suppress outgassing, improve immersion liquid followability in immersion exposure, reduce immersion defects, and the like.
The hydrophobic resin (D) is preferably designed so as to be unevenly distributed on the surface of the resist film. It does not have to contribute to uniform mixing.

The hydrophobic resin (D) is selected from the group consisting of "fluorine atom", "silicon atom", and " _CH3 partial structure contained in the side chain portion of the resin" from the viewpoint of uneven distribution on the film surface layer. It is preferable that the resin has a repeating unit having at least one kind of
When the hydrophobic resin (D) contains fluorine atoms and / or silicon atoms, the fluorine atoms and / or silicon atoms in the hydrophobic resin (D) may be contained in the main chain of the resin, It may be contained in a chain.

When the hydrophobic resin (D) contains a fluorine atom, the partial structure having a fluorine atom may be a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom. preferable.

The hydrophobic resin (D) preferably has at least one group selected from the group (x) to (z) below.
(x) an acid group; (y) a group that decomposes under the action of an alkaline developer to increase its solubility in the alkaline developer (hereinafter also referred to as a polarity conversion group);
(z) a group that decomposes under the action of an acid

The acid group (x) includes phenolic hydroxyl group, carboxylic acid group, fluorinated alcohol group, sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl)(alkylcarbonyl)methylene group, (alkylsulfonyl)(alkyl carbonyl)imide group, bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris(alkylcarbonyl)methylene group, and tris(alkylsulfonyl) ) methylene group and the like.
Preferred acid groups are fluorinated alcohol groups (preferably hexafluoroisopropanol), sulfonimide groups, or bis(alkylcarbonyl)methylene groups.

Examples of the group (y) that decomposes under the action of an alkaline developer to increase the solubility in the alkaline developer include a lactone group, a carboxylic acid ester group (—COO—), an acid anhydride group (—C(O)OC (O)-), an acid imide group (-NHCONH-), a carboxylic acid thioester group (-COS-), a carbonate group (-OC(O)O-), a sulfate group (-OSO ₂ O-), and A sulfonic acid ester group (--SO ₂ O--) and the like can be mentioned, and a lactone group or a carboxylic acid ester group (--COO--) is preferred.
Repeating units containing these groups are, for example, repeating units in which these groups are directly bonded to the main chain of the resin, and examples thereof include repeating units of acrylic acid esters and methacrylic acid esters. These repeating units may be bonded to the main chain of the resin via a linking group. Alternatively, this repeating unit may be introduced at the end of the resin using a polymerization initiator or chain transfer agent having these groups during polymerization.
Examples of the repeating unit having a lactone group include those similar to the repeating unit having a lactone structure described above in the section of resin (A).

The content of the repeating unit having a group (y) that is decomposed by the action of an alkaline developer to increase the solubility in the alkaline developer is 1 to 100 mol% with respect to the total repeating units in the hydrophobic resin (D). is preferred, 3 to 98 mol% is more preferred, and 5 to 95 mol% is even more preferred.

Examples of the repeating unit having a group (z) decomposable by the action of an acid in the hydrophobic resin (D) are the same as the repeating units having an acid-decomposable group exemplified for the resin (A). A repeating unit having a group (z) decomposable under the action of an acid may have at least one of a fluorine atom and a silicon atom. The content of repeating units having a group (z) decomposable by the action of an acid is preferably 1 to 80 mol%, more preferably 10 to 80 mol%, relative to all repeating units in the hydrophobic resin (D). , 20 to 60 mol % is more preferred.
The hydrophobic resin (D) may further have repeating units other than the repeating units described above.

The repeating unit having a fluorine atom is preferably 10 to 100 mol %, more preferably 30 to 100 mol %, relative to all repeating units in the hydrophobic resin (D). Also, the repeating unit having a silicon atom is preferably 10 to 100 mol %, more preferably 20 to 100 mol %, relative to all repeating units in the hydrophobic resin (D).

On the other hand, especially when the hydrophobic resin (D) contains a CH ₃ partial structure in the side chain portion, it is also preferable that the hydrophobic resin (D) does not substantially contain fluorine atoms and silicon atoms. Moreover, it is preferable that the hydrophobic resin (D) is substantially composed only of repeating units composed only of atoms selected from carbon atoms, oxygen atoms, hydrogen atoms, nitrogen atoms and sulfur atoms.

The weight average molecular weight of the hydrophobic resin (D) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000.

The total content of residual monomers and/or oligomer components contained in the hydrophobic resin (D) is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass. Further, the dispersity (Mw/Mn) is preferably in the range of 1-5, more preferably in the range of 1-3.

As the hydrophobic resin (D), known resins can be appropriately selected and used either singly or as a mixture thereof. For example, known resins disclosed in paragraphs [0451] to [0704] of US Patent Application Publication No. 2015/0168830A1 and paragraphs [0340] to [0356] of US Patent Application Publication No. 2016/0274458A1 can be suitably used as the hydrophobic resin (D). Further, repeating units disclosed in paragraphs [0177] to [0258] of US Patent Application Publication No. 2016/0237190A1 are also preferable as repeating units constituting the hydrophobic resin (D).

Preferred examples of the monomer corresponding to the repeating unit constituting the hydrophobic resin (D) are shown below.

The hydrophobic resin (D) may be used alone or in combination of two or more.
It is preferable to use a mixture of two or more kinds of hydrophobic resins (D) having different surface energies from the viewpoint of compatibility between immersion liquid followability and development characteristics in immersion exposure.
The content of the hydrophobic resin (D) in the resist composition is preferably 0.01 to 20.0% by mass, more preferably 0.05 to 8.0% by mass, based on the total solid content in the composition. .

<Solvent (E)>
The resist composition contains a solvent.
The solvent contained in the resist composition may include not only the solvent brought in by the polymer solution, but also the solvent separately added during the step B.
A known resist solvent can be used as appropriate in the resist composition. For example, paragraphs [0665]-[0670] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0210]-[0235] of US Patent Application Publication No. 2015/0004544A1, US Patent Application Publication No. 2016/0237190A1 Known solvents disclosed in paragraphs [0424] to [0426] of the specification and paragraphs [0357] to [0366] of US Patent Application Publication No. 2016/0274458A1 can be suitably used.
Solvents that can be used in preparing the resist composition include, for example, alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactate esters, alkyl alkoxypropionates, and cyclic lactones (preferably having 4 to 10 carbon atoms). , monoketone compounds which may have a ring (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates.

As the organic solvent, a mixed solvent in which a solvent having a hydroxyl group in its structure and a solvent having no hydroxyl group are mixed may be used.
As the solvent having a hydroxyl group and the solvent not having a hydroxyl group, the aforementioned exemplary compounds can be appropriately selected. As the solvent containing a hydroxyl group, alkylene glycol monoalkyl ether, alkyl lactate, etc. are preferable, and propylene glycol monomethyl ether ( PGME), propylene glycol monoethyl ether (PGEE), methyl 2-hydroxyisobutyrate, or ethyl lactate are more preferred. As the solvent having no hydroxyl group, alkylene glycol monoalkyl ether acetate, alkylalkoxypropionate, monoketone compound which may have a ring, cyclic lactone, or alkyl acetate are preferable. Glycol monomethyl ether acetate (PGMEA), ethyl ethoxy propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, cyclopentanone or butyl acetate are more preferred, propylene glycol monomethyl ether acetate, γ-butyrolactone, ethyl ethoxy propionate, Cyclohexanone, cyclopentanone or 2-heptanone are more preferred. Propylene carbonate is also preferred as the solvent having no hydroxyl group.
The mixing ratio (mass ratio) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. preferable. A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is preferable from the viewpoint of coating uniformity.
The solvent preferably contains propylene glycol monomethyl ether acetate, and may be a single solvent of propylene glycol monomethyl ether acetate or a mixed solvent of two or more kinds containing propylene glycol monomethyl ether acetate.

<Surfactant (F)>
The resist composition may contain a surfactant. When a surfactant is included, a fluorine-based and/or silicon-based surfactant (specifically, a fluorine-based surfactant, a silicon-based surfactant, or a surfactant having both fluorine atoms and silicon atoms) is preferred.

By including a surfactant in the resist composition, when an exposure light source of 250 nm or less, particularly 220 nm or less is used, a pattern with good adhesion and little development defects can be obtained with good sensitivity and resolution.
Fluorinated and/or silicon-based surfactants include surfactants described in paragraph [0276] of US Patent Application Publication No. 2008/0248425.
Also, other surfactants than the fluorine-based and/or silicon-based surfactants described in paragraph [0280] of US Patent Application Publication No. 2008/0248425 can be used.

These surfactants may be used singly or in combination of two or more.
When the resist composition contains a surfactant, the content of the surfactant is, for example, 0.0001 to 20% by mass, and 0.0001 to 2.0% by mass, based on the total solid content of the composition. is preferred, and 0.0005 to 1.0% by mass is more preferred.
On the other hand, when the content of the surfactant is 10 ppm or more relative to the total solid content of the composition, the uneven surface distribution of the hydrophobic resin (D) is increased. As a result, the surface of the resist film formed from the resist composition can be made more hydrophobic, and the water followability during immersion exposure is improved.

<Other additives>
The resist composition may further contain other additives such as acid multipliers, dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors, and dissolution accelerators. .

<Preparation method>
The solid content concentration of the resist composition is generally preferably 1.0 to 10% by mass, more preferably 2.0 to 5.7% by mass, when the light source wavelength used in the exposure step is other than KrF rays. 0 to 5.3% by mass is more preferable. When the light source wavelength used in the exposure step is KrF rays, the content is generally preferably 1.0 to 50% by mass, more preferably 2.0 to 30% by mass. The solid content concentration is the mass percentage of the mass of other resist components excluding the solvent relative to the total mass of the composition.

In addition, from the viewpoint of improving resolution, the thickness of the resist film formed from the resist composition is preferably 90 nm or less, more preferably 85 nm or less, when the light source wavelength used in the exposure step is other than KrF rays. When the light source wavelength used for is KrF rays, the wavelength is preferably 1000 nm or less, more preferably 800 nm or less. Such a film thickness can be obtained by setting the solid content concentration in the resist composition within an appropriate range to provide an appropriate viscosity, thereby improving coating properties or film-forming properties.

The resist composition is used by dissolving the above components in a given organic solvent, preferably in the above mixed solvent, filtering the solution through a filter, and coating it on a given support (substrate). The pore size of the filter used for filtration is preferably 0.1 µm or less, more preferably 0.05 µm or less, and even more preferably 0.03 µm or less. Further, when the resist composition has a high solid content concentration (for example, 25% by mass or more), the pore size of the filter used for filtering is preferably 3 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. . The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon. In filter filtration, for example, as disclosed in Japanese Patent Application Publication No. 2002-62667 (JP 2002-62667), cyclic filtration may be performed, and multiple types of filters are connected in series or in parallel. Filtration may be performed by connecting to Also, the resist composition may be filtered multiple times. Furthermore, before and after filtering, the resist composition may be subjected to a degassing treatment or the like.

[Use]
The resist composition obtained by the production method of the present invention corresponds to a resist composition that reacts with exposure to actinic rays or radiation to change its properties. More specifically, the resist composition obtained by the production method of the present invention can be used in semiconductor manufacturing processes such as IC (Integrated Circuit), manufacturing of circuit boards such as liquid crystal or thermal heads, manufacturing of imprint mold structures, and other processes. The present invention relates to a resist composition used in a photofabrication process, or in the production of a lithographic printing plate or an acid-curable composition.
The pattern formed in the present invention can be used in an etching process, an ion implantation process, a bump electrode forming process, a rewiring forming process, MEMS (Micro Electro Mechanical Systems), and the like.

[Pattern Forming Method]
The pattern forming method of the present invention will be described below.
The pattern forming method of the present invention comprises
(i) a step of forming a resist film (actinic ray-sensitive or radiation-sensitive film) on a support using the resist composition obtained by the production method of the present invention described above (resist film forming step);
(ii) a step of exposing the resist film (irradiating actinic rays or radiation) (exposure step);
(iii) a step of developing the exposed resist film using a developer (development step);
have

The pattern forming method of the present invention is not particularly limited as long as it includes the above steps (i) to (iii), and may further include the following steps.
In the pattern forming method of the present invention, the exposure method in the (ii) exposure step may be liquid immersion exposure.
The pattern forming method of the present invention preferably includes (iv) a pre-heating (PB: PreBake) step before the (ii) exposure step.
The pattern forming method of the present invention preferably includes (v) a post exposure bake (PEB) step after (ii) the exposure step and (iii) before the development step.
The pattern forming method of the present invention may include (ii) the exposure step multiple times.
The pattern forming method of the present invention may include (iv) the preheating step multiple times.
The pattern forming method of the present invention may include (v) the post-exposure heating step multiple times.

In the pattern forming method of the present invention, the above-described (i) film formation step, (ii) exposure step, and (iii) development step can be performed by generally known methods.
If necessary, a resist underlayer film (for example, SOG (Spin On Glass), SOC (Spin On Carbon), and antireflection film) may be formed between the resist film and the support. As a material constituting the resist underlayer film, a known organic or inorganic material can be appropriately used.
A protective film (top coat) may be formed on the resist film. A known material can be used as appropriate for the protective film. For example, US2007/0178407, US2008/0085466, US2007/0275326, US2016/0299432, The composition for forming a protective film disclosed in US Patent Application Publication No. 2013/0244438 and International Patent Application Publication No. 2016/157988A can be preferably used. As the composition for forming a protective film, a composition containing the acid diffusion control agent described above is preferable.
A protective film may be formed on the resist film containing the hydrophobic resin described above.

The support is not particularly limited, and is generally used in the manufacturing process of semiconductors such as ICs, the manufacturing process of circuit boards such as liquid crystals or thermal heads, and the lithography process of other photofabrications. A substrate can be used. Specific examples of the support include inorganic substrates such as silicon, SiO ₂ , and SiN.

The heating temperature is preferably 70 to 130.degree. C., more preferably 80 to 130.degree. C., even more preferably 80 to 120.degree.
The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and even more preferably 30 to 90 seconds in both (iv) the preheating step and (v) the post-exposure heating step.
Heating can be performed by means provided in the exposure device and the development device, and may be performed using a hot plate or the like.

The wavelength of the light source used in the exposure process is not limited, but examples thereof include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and electron beams. Among these, far ultraviolet light is preferred, and its wavelength is preferably 250 nm or less, more preferably 220 nm or less, and still more preferably 1 to 200 nm. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), _F2 excimer laser (157 nm), X-ray, EUV (13 nm), electron beam, etc., KrF excimer laser, ArF excimer laser, EUV or electron beam are preferred.

(iii) In the developing step, an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer) may be used.

As the alkaline developer, quaternary ammonium salts such as tetramethylammonium hydroxide are usually used, but in addition to this, alkaline aqueous solutions such as inorganic alkalis, primary to tertiary amines, alcohol amines, and cyclic amines are also used. Available.
Further, the alkaline developer may contain appropriate amounts of alcohols and/or surfactants. The alkali concentration of the alkali developer is usually 0.1 to 20 mass %. The pH of the alkaline developer is usually 10-15.
The time for developing with an alkaline developer is usually 10 to 300 seconds.
The alkali concentration, pH, and development time of the alkali developer can be appropriately adjusted according to the pattern to be formed.

The organic developer is a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. is preferred.

Ketone solvents include, for example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, Cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, and propylene carbonate.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and diethylene glycol monoethyl. ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butane butyl acid, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, butyl propionate and the like.

As alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents, the solvents disclosed in paragraphs [0715] to [0718] of US Patent Application Publication No. 2016/0070167A1 can be used.

A plurality of the above solvents may be mixed, or may be mixed with a solvent other than the above or water. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, even more preferably less than 10% by mass, most preferably less than 0 to 5% by mass, and substantially free of water. is particularly preferred.
The content of the organic solvent in the organic developer is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and 95 to 100% by mass, relative to the total amount of the developer. % is particularly preferred.

The organic developer may contain an appropriate amount of a known surfactant as required.

The content of the surfactant is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, more preferably 0.01 to 0.5% by mass, relative to the total amount of the developer.

The organic developer may contain the acid diffusion control agent described above.

Examples of the developing method include a method of immersing the substrate in a tank filled with a developer for a certain period of time (dip method), a method of raising the developer on the surface of the substrate by surface tension and resting the substrate for a certain period of time (paddle method), and a substrate. A method of spraying the developer onto the surface (spray method), or a method of continuously discharging the developer while scanning the developer discharge nozzle at a constant speed onto the substrate rotating at a constant speed (dynamic dispensing method). be done.

A step of developing using an alkaline aqueous solution (alkali developing step) and a step of developing using a developer containing an organic solvent (organic solvent developing step) may be combined. As a result, the pattern can be formed without dissolving only the intermediate exposure intensity region, so that a finer pattern can be formed.

(iii) It is preferable to include a step of washing with a rinse solution (rinse step) after the development step.

Pure water, for example, can be used as the rinsing solution used in the rinsing step after the developing step using the alkaline developer. The pure water may contain an appropriate amount of surfactant. In this case, after the developing process or the rinsing process, a process of removing the developing solution or rinsing solution adhering to the pattern with a supercritical fluid may be added. Further, after rinsing or supercritical fluid treatment, heat treatment may be performed to remove moisture remaining in the pattern.

The rinsing liquid used in the rinsing step after the development step using the developer containing an organic solvent is not particularly limited as long as it does not dissolve the pattern, and a common solution containing an organic solvent can be used. A rinse solution containing at least one organic solvent selected from the group consisting of hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, and ether-based solvents is used as the rinse solution. is preferred.
Specific examples of the hydrocarbon-based solvent, ketone-based solvent, ester-based solvent, alcohol-based solvent, amide-based solvent, and ether-based solvent are the same as those described for the developer containing an organic solvent.
As the rinse solution used in the rinse step in this case, a rinse solution containing a monohydric alcohol is more preferable.

Monohydric alcohols used in the rinse step include linear, branched, or cyclic monohydric alcohols. Specifically, 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1 -heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and methylisobutylcarbinol. Examples of monohydric alcohols having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, 3-methyl-1-butanol, and methylisobutylcarbinol. .

A plurality of each component may be mixed, or may be used by mixing with an organic solvent other than the above.
The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less. By setting the water content to 10% by mass or less, good developing properties can be obtained.

The rinse liquid may contain an appropriate amount of surfactant.
In the rinsing step, the substrate developed with the organic developer is washed with a rinsing solution containing an organic solvent. The method of the cleaning treatment is not particularly limited, but for example, a method of continuously discharging the rinse solution onto the substrate rotating at a constant speed (rotation coating method), or a method of immersing the substrate in a tank filled with the rinse solution for a certain period of time. method (dip method), or a method of spraying a rinse liquid onto the substrate surface (spray method). Among them, it is preferable that the cleaning treatment is performed by a spin coating method, and after cleaning, the substrate is rotated at a rotation speed of 2,000 to 4,000 rpm to remove the rinse solution from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. This heating process removes the developer and rinse remaining between the patterns and inside the patterns. In the heating step after the rinsing step, the heating temperature is usually 40 to 160°C, preferably 70 to 95°C, and the heating time is usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

The resist composition obtained by the production method of the present invention, and various materials used in the pattern forming method of the present invention (e.g., developer, rinse, antireflection film-forming composition, or topcoat-forming composition) etc.) preferably does not contain impurities such as metal components, isomers, and residual monomers. The content of these impurities contained in the above various materials is preferably 1 ppm or less, more preferably 100 ppt or less, still more preferably 10 ppt or less, and substantially free (below the detection limit of the measuring device). is particularly preferred.

As a method for removing impurities such as metals from the above various materials, for example, filtration using a filter can be mentioned. The pore size of the filter is preferably 10 nm or less, more preferably 5 nm or less, and even more preferably 3 nm or less. As the material of the filter, a filter made of polytetrafluoroethylene, polyethylene, or nylon is preferable. A filter that has been pre-washed with an organic solvent may be used. In the filter filtration step, multiple types of filters may be connected in series or in parallel for use. When multiple types of filters are used, filters with different pore sizes and/or materials may be used in combination. Further, various materials may be filtered multiple times, and the process of filtering multiple times may be a circulation filtration process. As the filter, those with reduced extractables as disclosed in Japanese Patent Application Publication No. 2016-201426 (JP 2016-201426) are preferable.
In addition to filter filtration, impurities may be removed using an adsorbent, or a combination of filter filtration and adsorbent may be used. As the adsorbent, a known adsorbent can be used. For example, an inorganic adsorbent such as silica gel or zeolite, or an organic adsorbent such as activated carbon can be used. Examples of metal adsorbents include those disclosed in Japanese Patent Application Publication No. 2016-206500 (JP 2016-206500).
In addition, as a method for reducing impurities such as metals contained in the various materials, selecting raw materials with a low metal content as raw materials constituting various materials, performing filter filtration on raw materials constituting various materials, Alternatively, distillation may be performed under conditions in which contamination is suppressed as much as possible by, for example, lining the inside of the apparatus with Teflon (registered trademark). It is also preferable to apply a glass lining treatment to all the processes of manufacturing equipment for synthesizing various materials (resins, photoacid generators, etc.) for resist components, in order to reduce impurities such as metals to the ppt order. Preferable conditions for filter filtration for raw materials constituting various materials are the same as those described above.

In order to prevent contamination of impurities, the above various materials are described in US Patent Application Publication No. 2015/0227049, Japanese Patent Application Publication No. 2015-123351 (JP 2015-123351), Japanese Patent It is preferably stored in a container described in Published Application No. 2017-13804 (Japanese Patent Application Laid-Open No. 2017-13804).

A method for improving surface roughness of the pattern may be applied to the pattern formed by the pattern forming method of the present invention. As a method of improving the surface roughness of the pattern, for example, there is a method of processing the pattern with hydrogen-containing gas plasma disclosed in US Patent Application Publication No. 2015/0104957. In addition, Japanese Patent Application Publication No. 2004-235468 (Japanese Patent Application Publication No. 2004-235468), US Patent Application Publication No. 2010/0020297, Proc. of SPIE Vol. 8328 83280N-1 “EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement” may be applied.
In addition, the pattern formed by the above method is, for example, the spacer process disclosed in Japanese Patent Application Publication No. 1991-270227 (JP-A-3-270227) and US Patent Application Publication No. 2013/0209941. can be used as a core of

[Method for producing electronic device]
The present invention also relates to a method of manufacturing an electronic device, including the pattern forming method described above. The electronic device manufactured by the method for manufacturing an electronic device of the present invention is suitably mounted in electrical and electronic equipment (for example, home appliances, OA (Office Automation) related equipment, media related equipment, optical equipment, communication equipment, etc.). be done.

The present invention will be described in more detail below based on examples. Materials, usage amounts, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the examples shown below.

[Synthesis of resins (P-AP1) to (P-AP6), resins (P-AN1) to (P-AN6), and resins (P-KP1) to (P-KP6), and polymer solution (P- AP1-0) ~ (P-AP1-6), polymer solutions (P-AN1-0) ~ (P-AN1-6), and polymer solutions (P-KP1-0) ~ (P-KP1-6) Preparation]
[Synthesis of resin (P-AP1) and preparation of polymer solution (P-AP1-0)]
A mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether was placed in a flask under a nitrogen stream and heated to 80° C. (solvent 1). Next, a monomer corresponding to each repeating unit of resin P-AP1 shown below was added to a mixed solvent of 6/4 (mass ratio) of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether at a molar ratio of 40/60. dissolved to prepare a monomer solution. Further, a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries) was added, and the dissolved solution was added dropwise to the above solvent 1 over 6 hours. After completion of the dropwise addition, the mixture was further reacted at 80° C. for 2 hours. The reaction mixture was allowed to cool, poured into hexane/ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain a resin (P-AP1). The obtained resin (P-AP1) had a weight average molecular weight of 8,000 and a dispersity (Mw/Mn) of 1.5. Furthermore, the resin (P-AP1) was dissolved in propylene glycol monomethyl ether acetate to obtain a 15 mass % polymer solution (P-AP1-0).

[Synthesis of resins (P-AP2) to (P-AP6), resins (P-AN1) to (P-AN6), and resins (P-KP1) to (P-KP6), and polymer solution (P- AP2-0) ~ (P-AP6-0), polymer solutions (P-AN1-0) ~ (P-AN6-0), and polymer solutions (P-KP1-0) ~ (P-KP6-0) Preparation]
Resins (P-AP2) to (P-AP6) shown in Table 1, resin (P-AN1) to (P-AN6) and resins (P-KP1) to (P-KP6) were synthesized. Further, by mixing each resin obtained and the solvent described in Table 1 so that the solid content concentration described in Table 1 is obtained, polymer solutions (P-AP2-0) to (P-AP6-0) , polymer solutions (P-AN1-0) to (P-AN6-0), and polymer solutions (P-KP1-0) to (P-KP6-0) were prepared.
Structures of resins (P-AP2) to (P-KP6) are shown below. Table 1 also shows the weight average molecular weights (Mw) and dispersities of the resins (P-AP2) to (P-KP6). In each structure of resins (P-AP2) to (P-KP6) shown below, the composition ratio of each repeating unit is meant to be a molar ratio.

[Preparation of resist composition]
[Step A (filtering step of polymer solution)]
The resulting polymer solutions (P-AP1-0) to (P-KP6-0) are subjected to step A (polymer solution filtration step) according to the procedure shown below to obtain a polymer solution (P-AP1- 1) ~ (P-KP6-1) were obtained.

<Purification Example 1: Preparation of polymer solution (P-AP1-1)>
First, a filtration facility comprising a first nylon membrane filter (Pall Ultipleated P-nylon, pore size 0.02 μm) was prepared.
Next, the prepared polymer solution (P-AP1-0) is passed through the first filter under the conditions of a linear velocity of 132 L/(hr·m ² ) in an environment of 22° C. to obtain a polymer solution ( P-AP1-1) was obtained. Purification Example 1 corresponds to a form in which the step A includes the above-described step X once.

<Purification Example 2: Preparation of polymer solution (P-AP1-2)>
First, a first nylon membrane filter (Pall Ultipleated P-nylon, pore size 0.02 μm) and a polyethylene membrane second filter (Entegris Microgard Plus, pore size 0.005 μm) were connected in series. Prepare the filtration equipment.
Next, the prepared polymer solution (P-AP1-0) is passed through the first and second filters in order under the conditions of a linear velocity of 132 L/(hr·m ² ) in an environment of 22°C. Thus, a polymer solution (P-AP1-2) was obtained. Purification Example 2 corresponds to a form in which the step A includes the above-described step X two or more times, and specifically corresponds to the above-described step (2). The first filter corresponds to the filter X1 described above, and the second filter corresponds to the filter X2 described above.

<Purification Example 3: Preparation of polymer solution (P-AP1-3)>
First, a first nylon membrane filter (Pall Ultipleated P-nylon, pore size 0.02 μm) and a polyethylene membrane second filter (Entegris Microgard Plus, pore size 0.005 μm) were connected in series. Prepare the filtration equipment.
Next, the prepared polymer solution (P-AP1-0) was applied to the first filter to the second filter five times in that order under the conditions of 22° C. and a linear velocity of 132 L/(hr·m ² ). By repeating the liquid passage, a polymer solution (P-AP1-3) was obtained. Purification Example 3 corresponds to a form in which the step A includes the above-described step X two or more times, and specifically corresponds to the above-described step (2). The first filter corresponds to the filter X1 described above, and the second filter corresponds to the filter X2 described above.

<Purification Examples 4 to 21>
Polymer solutions ((P-AP1-4) to (P-KP6-1)) shown in Table 2 were obtained in the same manner except for the polymer solution used, filter, linear velocity and temperature.
In Table 2, "PTFE" in Purification Example 4 means polytetrafluoroethylene. Specifically, it is “TorrentoX” manufactured by Entegris.

[Measurement of specific metal atom content in polymer solution]
Polymer solutions (P-AP1-0) to (P-KP6-1) obtained in [Step A (filtering step of polymer solution)] described above, and [Step A (filtering step of polymer solution)] described above For the polymer solutions (P-AP1-0), (P-AP2-0), and (P-AP3-0) in which the .
Specifically, using ICP-MS, Agilent-7500cs manufactured by Agilent Technologies, Na, K, Ca, Fe, Cu, Mg, Mn, Al, Li, Cr, Ni, Sn, Zn, Ag, As , Au, Ba, Cd, Co, Pb, V, W, Zr, and Mo. ppb) were obtained. Table 3 shows the measurement results.

From the results in Table 3, it is clear that when the acid-decomposable resin contains one or more of a carbonate structure and a sultone structure, the effect of reducing specific metal impurities in step A is superior.

[Step B (preparation of resist composition)]
<Preparation of resist compositions R-1 to R-21 and RC-1 to RC-3>
First, a nylon membrane first filter (pore size: 0.01 μm), a polyethylene membrane second filter (pore size: 0.002 μm), and a polyethylene membrane third filter (pore size: 0.002 μm) were separated. Filtration facilities connected in series in this order were prepared.
Next, each component was mixed according to the formulation shown in Table 4 below, and the resulting mixed solution was passed through the filtration equipment to obtain a resist composition (R-1 to R- 21, RC-1 to RC-3).

The structure of each component used in Table 4 is shown below.

(Photoacid generator)

(basic compound)

(Additive)

A-3: Megafac R-41 (manufactured by DIC Corporation) (fluorine-based)

(solvent)
SL-1: Propylene glycol monomethyl ether acetate (PGMEA)
SL-2: Propylene glycol monomethyl ether (PGME)
SL-3: γ-BL (GBL)
SL-4: Cyclohexanone

[Pattern formation (ArF exposure, positive development) and evaluation]
[Examples AP-1 to AP-9, Comparative Example AP-1]
An organic antireflection film-forming composition ARC29SR (manufactured by Nissan Chemical Industries, Ltd.) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form an antireflection film with a thickness of 95 nm. Each of resist compositions R-1 to R-9 and RC-1 was applied thereon and baked at 90° C. for 60 seconds to form a resist film having a thickness of 85 nm. Using an ArF excimer laser immersion scanner (manufactured by ASML, XT1700i, NA 1.20, Dipole, outer sigma 0.981, inner sigma 0.895, Y deflection), the obtained wafer was a halftone exposure mask with a transmittance of 6%. Pattern exposure was performed via (line/space=1/1). Pure water was used as the immersion liquid. Then, after heating at 100° C. for 60 seconds, a pattern with a pitch of 130 nm and a line width of 65 nm was obtained by puddle development (positive development) with an aqueous tetramethylammonium solution (2.38 mass %) for 30 seconds. Defects on the obtained resist pattern were inspected by Uvision 5 manufactured by AMAT, and the number of bridge defects (pieces/cm ² ) was measured. Table 5 shows the results.

From the results in Table 5, it is clear that when the resist composition obtained by the manufacturing method of the example is used, bridge defects occurring on the pattern after development can be suppressed (the number of bridge defects occurring is small).
Further, from a comparison of Examples AP-1 to AP-9, when the acid-decomposable resin contained in the resist composition contains one or more of a carbonate structure and a sultone structure, it occurs on the pattern after development. (Comparison between Examples AP-1 to AP-7 and Examples AP-8 and AP-9).
On the other hand, when the resist composition obtained by the manufacturing method of the comparative example is used, the bridging defect occurring on the pattern after development cannot be suppressed.

[Pattern formation (ArF exposure, negative development) and evaluation]
[Examples AN-1 to AN-6, Comparative Example AN-1]
An organic antireflection film-forming composition ARC29SR (manufactured by Nissan Chemical Industries, Ltd.) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form an antireflection film with a thickness of 95 nm. Resist compositions R-10 to R-15 and RC-2 were applied thereon and baked at 90° C. for 60 seconds to form a resist film having a thickness of 85 nm. Using an ArF excimer laser immersion scanner (manufactured by ASML, XT1700i, NA 1.20, Dipole, outer sigma 0.981, inner sigma 0.895, Y deflection), the obtained wafer was a halftone exposure mask with a transmittance of 6%. Pattern exposure was performed via (line/space=1/1). Pure water was used as the immersion liquid. Then, after heating at 100° C. for 60 seconds, development (negative development) was performed by puddling with butyl acetate for 60 seconds to obtain a pattern with a pitch of 130 nm and a line width of 65 nm. Defects on the obtained resist pattern were inspected by Uvision 5 manufactured by AMAT, and the number of bridge defects (pieces/cm ² ) was measured. Table 6 shows the results.

From the results in Table 6, it is clear that when the resist composition obtained by the manufacturing method of the example is used, bridge defects occurring on the pattern after development can be suppressed (the number of bridge defects occurring is small).
Further, from a comparison of Examples AN-1 to AN-6, when the acid-decomposable resin contained in the resist composition contains one or more of a carbonate structure and a sultone structure, it occurs on the pattern after development. (Comparison between Examples AN-1 to AN-4 and Examples AN-5 and AN-6).
On the other hand, when the resist composition obtained by the manufacturing method of the comparative example is used, the bridging defect occurring on the pattern after development cannot be suppressed.

[Pattern formation (KrF exposure, positive development) and evaluation]
[Examples KP-1 to KP-6, Comparative Example KP-1]
An organic antireflection film forming composition DUV42 (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form an antireflection film with a thickness of 64 nm. Resist compositions R-16 to 21 and RC-3 were applied thereon and baked at 130° C. for 60 seconds to form a resist film having a thickness of 600 nm. The resulting wafer was exposed through a binary exposure mask (line/space=1/1) using a KrF excimer laser (ASML PASS, NA 0.7, Dipole, outer sigma 0.8, inner sigma 0.7). Then, pattern exposure was performed. Then, after heating at 130° C. for 60 seconds, a pattern with a pitch of 400 nm and a line width of 200 nm was obtained by puddle development (positive development) with an aqueous tetramethylammonium solution (2.38 mass %) for 60 seconds. Defects on the obtained resist pattern were inspected with 2360 manufactured by KLA, and the number of bridge defects (pieces/cm ² ) was measured.

From the results in Table 7, it is clear that when the resist composition obtained by the manufacturing method of the example is used, bridge defects occurring on the pattern after development can be suppressed (the number of bridge defects occurring is small).
Further, from a comparison of Examples KP-1 to KP-6, when the acid-decomposable resin contained in the resist composition contains one or more of a carbonate structure and a sultone structure, it occurs on the pattern after development. It is clear that the bridging defects that occur can be further suppressed (comparison between Examples KP-1 and KP-2 and Examples KP-3 and KP-6).
On the other hand, when the resist composition obtained by the manufacturing method of the comparative example is used, the bridging defect occurring on the pattern after development cannot be suppressed.

Claims (6)

A method for producing an actinic ray-sensitive or radiation-sensitive resin composition used in a semiconductor device manufacturing process,
A step A of purifying a polymer solution containing a resin that is decomposed by the action of an acid to increase its polarity and a solvent;
A step B of adding a compound that generates an acid upon exposure to actinic rays or radiation to the polymer solution that has undergone step A to prepare an actinic ray-sensitive or radiation-sensitive resin composition,
The step A comprises a step X of filtering the polymer solution through a filter X,
The resin that is decomposed by the action of an acid to increase its polarity contains one or more of a carbonate structure and a sultone structure,
The differential pressure of the filter X is 0.3 MPa or less,
The step X comprises a step X1 of filtering the polymer solution through a filter X1 and a step X2 of filtering the polymer solution after the step X1 through a filter X2,
The filter X1 is a polyamide resin membrane, and the filter X2 is selected from the group consisting of a polyolefin resin having a pore size of 0.01 μm or less and a fluororesin membrane having a pore size of 0.01 μm or less, and the pore size of the filter is larger than that of the filter X2. The pore size of X1 is larger,
A method for producing an actinic ray-sensitive or radiation-sensitive resin composition , wherein the pressure difference between the filter X1 and the filter X2 is 0.3 MPa or less . 2. The actinic ray-sensitive or radiation-sensitive according to claim 1, wherein the polymer solution in the step A does not substantially contain components other than the solvent and the resin that is decomposed by the action of the acid to increase the polarity. a method for producing a flexible resin composition. The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the step X is carried out in a temperature environment of 15 to 25°C. 4. The resin according to any one of claims 1 to 3 , wherein the resin that is decomposed by the action of an acid to increase its polarity includes a resin containing a repeating unit derived from at least one of an acrylic acid ester and a methacrylic acid ester. A method for producing an actinic ray-sensitive or radiation-sensitive resin composition. Using the actinic ray- or radiation-sensitive resin composition produced by the method for producing an actinic ray- or radiation-sensitive resin composition according to any one of claims 1 to 4 , a step of forming a resist film;
exposing the resist film;
and developing the exposed resist film using a developer. A method for manufacturing an electronic device, comprising the pattern forming method according to claim 5 .

Images