WO2018030445A1

WO2018030445A1 - Chemically amplified resist material, and method for forming resist pattern

Info

Publication number: WO2018030445A1
Application number: PCT/JP2017/028854
Authority: WO
Inventors: 精一田川; 大島　明博; 誠司永原; 恭志中川; 岳彦成岡; 永井　智樹
Original assignee: 国立大学法人大阪大学; 東京エレクトロン株式会社; Jsr株式会社
Priority date: 2016-08-08
Filing date: 2017-08-08
Publication date: 2018-02-15
Also published as: JP2019168475A

Abstract

Provided are: a chemically amplified resist material which can have high sensitivity and excellent lithographic performance; and a method for forming a resist pattern using the chemically amplified resist material. The chemically amplified resist material according to the present invention comprises (1) a polymer component which becomes soluble or insoluble in a developing solution by the action of an acid, (2) a component which can generate a radiation-sensitive sensitizer and an acid upon the exposure to light and (3) a component which has basicity relative to the acid generated from the component (2), wherein the component (2) contains a component (a) as mentioned below or any two or all of components (a) to (c) as mentioned below, the component (a) or the component (c) comprises a first compound having a radiation-sensitive acid generating group, and the component (3) contains a second compound that is a component (d) as mentioned below: (a) a radiation-sensitive acid-sensitizer generator; (b) a radiation-sensitive sensitizer generator; (c) a radiation-sensitive acid generator; and (d) a radiation-sensitive and photo-degradable base.

Description

Chemically amplified resist material and resist pattern forming method

The present invention relates to a chemically amplified resist material and a resist pattern forming method.

EUV (extreme ultraviolet light) lithography has attracted attention as one of the elemental technologies for manufacturing next-generation semiconductor devices. EUV lithography is a pattern formation technique that uses EUV light having a wavelength of 13.5 nm as an exposure light source. According to EUV lithography, it has been demonstrated that an extremely fine pattern (for example, 20 nm or less) can be formed in the exposure step of the semiconductor device manufacturing process.

However, the EUV light source currently being developed has a low output, so that the exposure process takes a long time. Therefore, EUV lithography has a disadvantage that it is not practical. In response to this inconvenience, a technique for improving the sensitivity of a resist material, which is a photosensitive resin, has been developed (see Japanese Patent Application Laid-Open No. 2002-174894).

JP 2002-174894 A

However, even the resist material in the above technique has insufficient sensitivity to EUV light, and if the sensitivity to EUV light is improved, there is a disadvantage that lithography performance such as nano edge roughness tends to deteriorate. This inconvenience also exists when an electron beam or the like is used as irradiation light.

The present invention has been made based on the circumstances as described above, and has an object of ionizing radiation such as EUV light, electron beam, ion beam, or a wavelength of 250 nm or less such as KrF excimer laser and ArF excimer laser. To provide a chemically amplified resist material capable of obtaining high sensitivity and excellent lithography performance when non-ionizing radiation is used as pattern exposure light, and a resist pattern forming method using this chemically amplified resist material. .

The invention made in order to solve the above problems includes (1) a polymer component that is soluble or insoluble in a developer by the action of an acid, and (2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure. And (3) a component that is relatively basic with respect to the acid generated by the component (2), the component (2) is the following component (a), and the following components (a) to (c): Contains any two of the components, or all of the following components (a) to (c), and the component (a) or component (c) has a first compound having a radiation-sensitive acid generating group. The component (3) is a chemically amplified resist material containing the second compound as the component (d) below.
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) is Radiation sensitivity that retains basicity with respect to the acid generated by the component (2) when the basic acid with respect to the generated acid is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base satisfies the following conditions (i) and (ii).
(I) It is represented by the following formula (x).
(Ii) a compound represented by the following formula (z) in which the monovalent anion represented by A ⁻ in the following formula (x) is replaced with a nonafluorobutanesulfonate anion, and the following formula (y) When compared with triphenylsulfonium nonafluorobutanesulfonate, the reduction potential of the monovalent onium cation represented by M ⁺ in the following formula (z) is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A ⁻ is a monovalent anion. M ⁺ is a monovalent onium cation.
In formula (z), M ⁺ has the same meaning as in formula (x). )

Another invention made to solve the above problems is as follows:
(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2), and
Including at least one of the component (2) and the component (3) as a structural unit of the polymer of the polymer component (1),
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) Radiation sensitivity that retains basicity with respect to the acid generated from the component (2) when the basic acid with respect to the acid generated is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base satisfies the following conditions (i) and (ii) or (ii).
(I) a compound represented by the following formula (x) and represented by the following formula (z) in which the monovalent anion represented by A ⁻ in the following formula (x) is replaced with a nonafluorobutanesulfonate anion; When the triphenylsulfonium nonafluorobutanesulfonate represented by the following formula (y) is compared, the reduction potential of the monovalent onium cation represented by M ⁺ in the following formula (z) is the reduction of the triphenylsulfonium cation. Higher than the potential.
(Ii) The above formula (z ′) in which a monovalent group containing a monovalent anion represented by A ⁻ in the following formula (x ′) is replaced with an octafluorobutanesulfonate group. ) And a triphenylsulfonium octafluorobutanesulfonate group represented by the following formula (y ′) and a monovalent onium cation represented by M ⁺ in the following formula (z ′) The reduction potential of is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A ⁻ is a monovalent anion. M ⁺ is a monovalent onium cation.
In formula (z), M ⁺ has the same meaning as in formula (x).
', A represents the formula (x)' ^- is a monovalent group comprising a monovalent anion. M ⁺ is synonymous with the formula (x). * Shows the site | part couple | bonded with a polymer.
In the formula (y ′), * is synonymous with the formula (x ′).
In formula (z ′), M ⁺ has the same meaning as in formula (x). * Is synonymous with the formula (x ′). )

Further, another invention made to solve the above problems includes a film formation step of forming a resist material film on at least one surface of a substrate using the chemically amplified resist material, and a 250 nm thickness on the resist material film. A pattern exposure step of irradiating radiation having the following wavelengths, a batch exposure step of irradiating the resist material film after the pattern exposure step with radiation having a wavelength exceeding 250 nm, and the resist material film after the batch exposure step A resist pattern forming method comprising: a baking process for heating the resist film; and a developing process for bringing the resist material film after the baking process into contact with a developer.

Moreover, another invention made in order to solve the said subject is:
(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2), and
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) is Radiation sensitivity that retains basicity with respect to the acid generated by the component (2) when the basic acid with respect to the generated acid is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base is a compound represented by the following formula (x), and the reduction potential of M ⁺ in the following formula (x) is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A ⁻ is a monovalent anion. M ⁺ is a monovalent onium cation.

Moreover, another invention made in order to solve the said subject is:
(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2), and
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) is Radiation sensitivity that retains basicity with respect to the acid generated by the component (2) when the basic acid with respect to the generated acid is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base satisfies the following conditions (i) and (ii).
(I) In the case of a compound represented by the following formula (x), the reduction potential of M ⁺ in the following formula (x) is higher than the reduction potential of the triphenylsulfonium cation.
(Ii) In the case of a group represented by the following formula (x ′), the reduction potential of the monovalent onium cation represented by M ⁺ in the following formula (x ′) is higher than the reduction potential of the triphenylsulfonium cation. .

(In formula (x), A ⁻ is a monovalent anion. M ⁺ is a monovalent onium cation.
', A represents the formula (x)' ^- is a monovalent group comprising a monovalent anion. M ⁺ is synonymous with the formula (x). * Shows the site | part couple | bonded with a polymer. )

Here, “when the first radiation is not irradiated and only the second radiation is irradiated, the acid and the radiation-sensitive sensitizer are not substantially generated”, “the first radiation is not irradiated and the second radiation is not irradiated. The radiation-sensitive sensitizer is not substantially generated when only the radiation is irradiated "and" the acid is not substantially generated when only the second radiation is irradiated without irradiating the first radiation ". "When an acid or radiation-sensitive sensitizer is not generated by irradiation with the second radiation, or even when an acid or radiation-sensitive sensitizer is generated by irradiation with the second radiation, The second radiation to such an extent that the difference in the concentration of the acid and the radiation-sensitive sensitizer between the exposed portion and the non-exposed portion in the pattern exposure for irradiating the first radiation can be maintained at a size that allows pattern formation. Acid and radiation sensitivity of non-exposed areas in the above pattern exposure by The amount of sensitizer generated is small, and as a result, the amount of acid or radiation-sensitive sensitizer generated is small enough to dissolve only the exposed or non-exposed portion of the pattern exposure in the developer after development. means.

The chemically amplified resist material of the present invention uses ionizing radiation such as EUV light, electron beam, ion beam, or non-ionizing radiation having a wavelength of 250 nm or less, such as KrF excimer laser and ArF excimer laser, as pattern exposure light. High sensitivity and excellent lithographic performance can be obtained. Further, the chemically amplified resist material can be suitably used for the resist pattern forming method.

It is process drawing which shows one Embodiment of the resist pattern formation method using the chemically amplified resist material which concerns on this invention. It is process drawing which shows an example of the resist pattern formation method using the conventional chemically amplified resist material. It is process drawing which shows another embodiment of the resist pattern formation method using the chemically amplified resist material which concerns on this invention. It is a conceptual diagram which shows the light absorbency of the pattern exposure part of a resist material film, and the light absorbency of an unexposed part as a graph. (A) is a conceptual diagram which shows the acid concentration distribution by the resist pattern formation method using the conventional chemically amplified resist material as a graph. (B) is a conceptual diagram showing the radiation-sensitive sensitizer concentration distribution and acid concentration distribution as a graph by the resist pattern forming method using the chemically amplified resist material according to the present embodiment. It is sectional drawing explaining an example of the manufacturing process of the semiconductor device which concerns on one Embodiment of this invention, (a) is sectional drawing which shows a resist pattern formation process, (b) is sectional drawing which shows an etching process. (C) is sectional drawing which shows a resist pattern removal process. It is a typical top view at the time of seeing a line pattern from the upper part. It is typical sectional drawing of a line pattern shape.

Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment.

<Chemically amplified resist material>
The chemically amplified resist material comprises (1) a polymer component that is soluble or insoluble in a developer by the action of an acid, (2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure, (3 And (2) a component having a basicity relative to the acid generated by the component.

The chemically amplified resist material contains a normal solvent in addition to (1) the polymer component, (2) component and (3) component, and (1) a polymer component other than the polymer component, an acid diffusion controller, a radical It may further contain a scavenger, a crosslinking agent, other additives and the like.

The component (2) includes any of the components (a), (a) to (c) described later, or any two components (a) to (c). Moreover, (a) component or (c) component has the 1st compound which has a radiation sensitive acid generating group, and the said (3) component contains the 2nd compound which is (d) component mentioned later.

At least one of the component (2) and the component (3) may be included as a structural unit of the polymer of the polymer component (1), and is a component different from the polymer component (1). May be. In this case, even if a part of the component (2), the component (3) or the combination thereof is a component different from the (1) polymer component, the component (2), the component (3) or the combination thereof is all (1) A component different from the polymer component may be used.

The upper limit of the wavelength of the first radiation is preferably 250 nm, and more preferably 200 nm. On the other hand, the lower limit of the wavelength of the second radiation is preferably more than 250 nm, and more preferably 300 nm. The upper limit of the wavelength of the second radiation is preferably 500 nm, and more preferably 400 nm.

[(1) Polymer component and (1) Polymer component other than polymer component]
(1) The polymer component is a component that becomes soluble or insoluble in the developer by the action of an acid. (1) The polymer component has, for example, a structural unit (hereinafter also referred to as “structural unit (I)”) containing a group that generates a polar group by the action of an acid (hereinafter also referred to as “acid-dissociable group”). Examples thereof include a first polymer (hereinafter also referred to as “[A] polymer”). Further, (1) a polymer component other than the polymer component may further include a second polymer not containing the structural unit (I) (hereinafter also referred to as “[B] polymer”).

[A] polymer or [B] polymer is a structural unit containing a fluorine atom (hereinafter also referred to as “structural unit (II)”, a structural unit (III) containing a phenolic hydroxyl group, a lactone structure, a cyclic carbonate structure. , May further have a structural unit (IV) containing a sultone structure or a combination thereof, and may further have other structural units other than the structural unit (I) to the structural unit (IV).

[[A] polymer and [B] polymer]
[A] The polymer is a polymer having the structural unit (I). [A] The polymer may further have structural units (II) to (IV) and other structural units. [B] The polymer is a polymer different from the [A] polymer. [B] The polymer preferably has structural unit (II), and has structural unit (III) and structural unit (IV), and other structural units other than structural unit (III) to structural unit (IV). May be.

(Structural unit (I))
The structural unit (I) is a structural unit containing an acid dissociable group. [A] Since the polymer has the structural unit (I), the sensitivity and lithography performance of the chemically amplified resist material can be further improved. Examples of the structural unit (I) include a structural unit represented by the following formula (a-1) (hereinafter also referred to as “structural unit (I-1)”) and a structure represented by the following formula (a-2). A unit (hereinafter also referred to as “structural unit (I-2)”). In the following formulas (a-1) and (a-2), groups represented by —CR ^A2 R ^A3 R ^A4 and —CR ^A6 R ^A7 R ^A8 are acid-dissociable groups.

In the above formula (a-1), R ^A1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^A2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^A3 and R ^A4 each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, or have 3 to 20 ring members composed of these groups together with the carbon atom to which they are bonded. Represents the ring structure of
In the above formula (a-2), R ^A5 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^A6 is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. R ^A7 and R ^A8 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. L ^A is a single bond, —O—, —COO— or —CONH—.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^A2 , R ^A6 , R ^A7 and R ^A8 include, for example, a chain hydrocarbon group having 1 to 30 carbon atoms, and a group having 3 to 30 carbon atoms. Examples thereof include an alicyclic hydrocarbon group and an aromatic hydrocarbon group having 6 to 30 carbon atoms.

Examples of the monovalent chain hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an i-propyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group and butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms include a saturated simple group such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclopentyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group. A cyclic hydrocarbon group;
Unsaturated monocyclic hydrocarbon groups such as cyclopropenyl group, cyclobutenyl group, cyclopentenyl group, cyclohexenyl group, cyclooctenyl group, cyclodecenyl group;
Saturated polycyclic hydrocarbon groups such as bicyclo [2.2.1] heptanyl group, bicyclo [2.2.2] octanyl group, tricyclo [3.3.1.1 ^3,7 ] decanyl group;
And unsaturated polycyclic hydrocarbon groups such as a bicyclo [2.2.1] heptenyl group and a bicyclo [2.2.2] octenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, a methylnaphthyl group, an anthryl group, and a methylanthryl group;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group and anthrylmethyl group.

R ^A2 is preferably a chain hydrocarbon group and a cycloalkyl group, more preferably an alkyl group and a cycloalkyl group, and a methyl group, an ethyl group, a propyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, and an adamantyl group. Further preferred.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms and the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^{A3 and} R ^A4 include the above R ^A2 and R ^A6. , Groups similar to those exemplified for R ^A7 and R ^A8 .

Examples of the alicyclic structure having 3 to 20 ring members composed of the R ^A3 and R ^A4 groups together with the carbon atom to which they are bonded include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclopentene structure, a cyclopentane structure, Monocyclic cycloalkane structures such as pentadiene structure, cyclohexane structure, cyclooctane structure, cyclodecane structure;
Examples thereof include polycyclic cycloalkane structures such as a norbornane structure, an adamantane structure, a tricyclodecane structure, and a tetracyclododecane structure.

As R ^A3 and R ^A4 , an alkyl group, a monocyclic cycloalkane structure, a norbornane structure, and an adamantane structure constituted by combining these groups are preferable, and a methyl group, an ethyl group, a cyclopentane structure, a cyclohexane structure, and An adamantane structure is more preferred.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms represented by R ^A6 , R ^A7 and R ^A8 include 1 to 20 carbon atoms of R ^A2 , R ^A6 , R ^A7 and R ^A8. Examples of the valent hydrocarbon group include groups containing an oxygen atom between carbon and carbon.

As said R ^<A6> , R ^<A7> and R ^<A8> , a chain hydrocarbon group and an alicyclic hydrocarbon group containing an oxygen atom are preferable.

As the ^{L A,} a single bond and -COO- is more preferably a single bond.

R ^A1 is preferably a hydrogen atom and a methyl group, more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (I).

R ^A5 is preferably a hydrogen atom and a methyl group, and more preferably a hydrogen atom, from the viewpoint of copolymerization of the monomer that gives the structural unit (I).

Examples of the structural unit (I-1) include structural units represented by the following formulas (a-1-a) to (a-1-d) (hereinafter referred to as “structural units (I-1-a) to (I -1-d) ”) and the like. Examples of the structural unit (I-2) include a structural unit represented by the following formula (a-2-a) (hereinafter also referred to as “structural unit (I-2-a)”).

In the above formulas (a-1-a) to (a-1-d), R ^A1 to R ^A4 have the same ^{meaning as} in the above formula (a-1). n _a is an integer of 1-4. In the above formula (a-2-a), R ^A5 to R ^A8 have the same ^{meaning as} in the above formula (a-2).

The n _a, preferably 1, 2 and 4, more preferably 1.

Examples of the structural units (I-1-a) to (I-1-d) include structural units represented by the following formulas.

In the above formula, R ^A1 has the same ^{meaning as} in the above formula (a-1).

Examples of the structural unit (I-2-a) include a structural unit represented by the following formula.

In the above formula, R ^A5 has the same ^{meaning as} in the above formula (a-2).

As the structural unit (I), structural units (I-1-a) to (I-1-d) are preferable, and a structural unit derived from 2-methyl-2-adamantyl (meth) acrylate, 2-ipropyl-2 A structural unit derived from adamantyl (meth) acrylate, a structural unit derived from 1-methyl-1-cyclopentyl (meth) acrylate, a structural unit derived from 1-ethyl-1-cyclohexyl (meth) acrylate, 1-ipropyl Structural units derived from 1-cyclopentyl (meth) acrylate, structural units derived from 2-cyclohexylpropan-2-yl (meth) acrylate, and 2- (adamantan-1-yl) propan-2-yl (meth) A structural unit derived from acrylate is more preferred.

[A] As a minimum of the content rate of structural unit (I) with respect to all the structural units which constitute a polymer, 10 mol% is preferred, 20 mol% is more preferred, 25 mol% is still more preferred, and 30 mol% is especially preferable. On the other hand, the upper limit of the content is preferably 80 mol%, more preferably 70 mol%, further preferably 65 mol%, particularly preferably 60 mol%. By setting the content ratio within the above range, it is possible to sufficiently ensure the dissolution contrast of the resist material film formed from the chemically amplified resist material with respect to the developer in the pattern exposed portion and the non-exposed portion, as a result. , Resolution and the like are improved.

(Structural unit (II))
The structural unit (II) is a structural unit containing a fluorine atom (except for those corresponding to the structural unit (I)). The structural unit (II) usually does not contain a salt structure.

[A] When the polymer has the structural unit (II), the lower limit of the content ratio of the structural unit (II) to all structural units constituting the [A] polymer is preferably 3 mol%, and 5 mol% More preferred is 10 mol%. On the other hand, as an upper limit of the said content rate, 40 mol% is preferable, 35 mol% is more preferable, and 30 mol% is further more preferable. By making the said content rate into the said range, the sensitivity in case EUV etc. are used as pattern exposure light can be improved more. On the other hand, when the said content rate exceeds the said upper limit, there exists a possibility that the rectangularity in the cross-sectional shape of a resist pattern may fall.

(1) When the polymer component includes the [B] polymer and the [B] polymer has the structural unit (II), the lower limit of the structural unit (II) with respect to all the structural units constituting the [B] polymer Is preferably 3 mol%, more preferably 5 mol%, still more preferably 10 mol%. On the other hand, as an upper limit of the said content rate, 40 mol% is preferable, 35 mol% is more preferable, and 30 mol% is further more preferable. By making the said content rate into the said range, the sensitivity in case EUV etc. are used as pattern exposure light can be improved more. On the other hand, when the said content rate exceeds the said upper limit, there exists a possibility that the rectangularity in the cross-sectional shape of a resist pattern may fall.

(Structural unit (III))
The structural unit (III) is a structural unit containing a phenolic hydroxyl group (except for those corresponding to the structural unit (I) and the structural unit (II)). Since the [A] polymer or the [B] polymer has the structural unit (III), the sensitivity in the case of irradiation with KrF excimer laser light, EUV (extreme ultraviolet), electron beam or the like in the pattern exposure process described later is further increased. Can be improved.

Part or all of the hydrogen atoms of the aromatic ring containing the phenolic hydroxyl group may be substituted with a substituent. Examples of this substituent include the same groups as those exemplified for R ^F5 and R ^F8 above.

Examples of the structural unit (III) include structural units represented by the following formulas (h-1) to (h-6) (hereinafter also referred to as “structural units (III-1) to (III-6)”) and the like. Can be mentioned.

In the above formulas (h-1) to (h-6), R ^AF1 is a hydrogen atom or a methyl group.

As said ^RAF1 , a hydrogen atom is preferable.

As the structural unit (III), structural units (III-1) and (III-2) are preferable, and (III-1) is more preferable.

[A] When the polymer has the structural unit (III), the lower limit of the content ratio of the structural unit (III) with respect to all the structural units constituting the [A] polymer is preferably 1 mol%, preferably 30 mol%. More preferred is 50 mol%. On the other hand, as an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 75 mol% is further more preferable. By making the content rate of structural unit (III) into the said range, the sensitivity of the said chemically amplified resist material can be improved more.

(1) When the polymer component includes the [B] polymer and the [B] polymer has the structural unit (III), the content ratio of the structural unit (III) to all the structural units constituting the [B] polymer Is preferably 1 mol%, more preferably 30 mol%, and even more preferably 50 mol%. On the other hand, as an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 75 mol% is further more preferable. By making the content rate of structural unit (III) into the said range, the sensitivity of the said chemically amplified resist material can be improved more.

The structural unit (III) is obtained by polymerizing a monomer in which a hydrogen atom of an —OH group of an aromatic ring containing a phenolic hydroxyl group is substituted with an acetyl group, and then hydrolyzing the resulting polymer in the presence of an amine. It can be formed by a reaction method or the like.

(Structural unit (IV))
The structural unit (IV) is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof (except for those corresponding to the structural unit (I) to the structural unit (III)). [A] The polymer and the [B] polymer can further adjust the solubility in the developer by further including the structural unit (IV), and as a result, the chemically amplified resist The lithographic performance of the material can be further improved. Adhesion between the resist material film formed from the chemically amplified resist material and the substrate can be improved. Here, the lactone structure refers to a structure having one ring (lactone ring) including a group represented by —O—C (O) —. The cyclic carbonate structure refers to a structure having one ring (cyclic carbonate ring) containing a group represented by —O—C (O) —O—. The sultone structure refers to a structure having one ring (sultone ring) including a group represented by —O—S (O) ₂ —.

As the structural unit (IV), a structural unit containing a norbornane lactone structure, a structural unit containing an oxanorbornane lactone structure, a structural unit containing a γ-butyrolactone structure, a structural unit containing an ethylene carbonate structure, and a structural unit containing a norbornane sultone structure A structural unit derived from norbornanelactone-yl (meth) acrylate, a structural unit derived from oxanorbornanelactone-yl (meth) acrylate, a structural unit derived from cyano-substituted norbornanelactone-yl (meth) acrylate, norbornane lactone -Structural units derived from yloxycarbonylmethyl (meth) acrylate, structural units derived from butyrolactone-3-yl (meth) acrylate, derived from butyrolactone-4-yl (meth) acrylate A structural unit derived from 3,5-dimethylbutyrolactone-3-yl (meth) acrylate, a structural unit derived from 4,5-dimethylbutyrolactone-4-yl (meth) acrylate, 1- (butyrolactone-3- Yl) structural units derived from cyclohexane-1-yl (meth) acrylate, structural units derived from ethylene carbonate-ylmethyl (meth) acrylate, structural units derived from cyclohexene carbonate-ylmethyl (meth) acrylate, norbornane sultone-yl ( A structural unit derived from (meth) acrylate and a structural unit derived from norbornane sultone-yloxycarbonylmethyl (meth) acrylate are more preferred.

[A] When the polymer has a structural unit (IV), the lower limit of the content ratio of the structural unit (IV) to all structural units constituting the [A] polymer is preferably 1 mol%, and 10 mol% More preferably, 20 mol% is more preferable, and 25 mol% is particularly preferable. On the other hand, the upper limit of the content is preferably 70 mol%, more preferably 65 mol%, still more preferably 60 mol%, and particularly preferably 55 mol%. By making the said content rate into the said range, the adhesiveness of the resist material film | membrane formed from the said chemically amplified resist material and a board | substrate can be improved more.

(1) When the polymer component includes the [B] polymer, and the [B] polymer has the structural unit (IV), the content ratio of the structural unit (IV) with respect to all the structural units constituting the [B] polymer. Is preferably 1 mol%, more preferably 10 mol%, further preferably 20 mol%, particularly preferably 25 mol%. On the other hand, the upper limit of the content is preferably 70 mol%, more preferably 65 mol%, still more preferably 60 mol%, and particularly preferably 55 mol%. By making the said content rate into the said range, the adhesiveness of the resist material film | membrane formed from the said chemically amplified resist material and a board | substrate can be improved more.

[Other structural units]
The [A] polymer and the [B] polymer may have other structural units in addition to the structural units (I) to (IV). Examples of other structural units include a structural unit containing a polar group and a structural unit containing a non-dissociable hydrocarbon group. Examples of the polar group include an alcoholic hydroxyl group, a carboxy group, a cyano group, a nitro group, and a sulfonamide group. Examples of the non-dissociable hydrocarbon group include a linear alkyl group. [A] As an upper limit of the content rate of the said other structural unit with respect to all the structural units which comprise a polymer, 20 mol% is preferable and 10 mol% is more preferable.

The lower limit of the total content of the [A] polymer and the [B] polymer is preferably 70% by mass, more preferably 75% by mass, and more preferably 80% by mass in the total solid content of the chemically amplified resist material. preferable. Here, “total solid content” refers to components other than the solvent of the chemically amplified resist material.

[A] The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is not particularly limited, but the lower limit thereof is preferably 1,000, more preferably 2,000, and 3,000. Is more preferable, and 5,000 is particularly preferable. On the other hand, the upper limit of the Mw of the [A] polymer is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 15,000. [A] By making Mw of a polymer into the said range, the applicability | paintability and development defect inhibitory property of the said chemically amplified resist material improve. [A] When Mw of the polymer is smaller than the lower limit, a resist material film having sufficient heat resistance may not be obtained. Conversely, when the Mw of the [A] polymer exceeds the above upper limit, the developability of the resist material film may be lowered.

[A] The lower limit of the ratio (Mw / Mn) of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer is usually 1. On the other hand, the upper limit of the ratio is usually 5, preferably 3 and more preferably 2.

[B] The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is not particularly limited, but the lower limit thereof is preferably 1,000, more preferably 2,000, and 2,500. Is more preferable, and 3,000 is particularly preferable. On the other hand, the upper limit of the Mw of the [B] polymer is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 15,000. [B] By making Mw of a polymer into the said range, the applicability | paintability and development defect inhibitory property of the said chemically amplified resist material improve. [B] If the Mw of the polymer is smaller than the lower limit, a resist material film having sufficient heat resistance may not be obtained. Conversely, if the Mw of the [B] polymer exceeds the above upper limit, the developability of the resist material film may be reduced.

[B] The lower limit of the ratio (Mw / Mn) of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer is preferably 1. On the other hand, the upper limit of the ratio is preferably 5, more preferably 3, and even more preferably 2.

In addition, Mw and Mn of the polymer in this specification are values measured using gel permeation chromatography (GPC) under the following conditions.
GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (above, Tosoh Corporation)
Column temperature: 40 ° C
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

The [A] polymer and the [B] polymer may contain a low molecular weight component having a molecular weight of 1,000 or less. [A] The upper limit of the content of the low molecular weight component in the polymer is preferably 1.0% by mass, more preferably 0.5% by mass, and still more preferably 0.3% by mass. As a minimum of the above-mentioned content, it is 0.01 mass%, for example. By setting the content of the low molecular weight component of the [A] polymer and the [B] polymer in the above range, the lithography performance of the chemically amplified resist material can be further improved.

In addition, the content of the low molecular weight component of the polymer in the present specification is a value measured using high performance liquid chromatography (HPLC) under the following conditions.
Column: GL Science's “Inertsil ODA-25 μm column” (4.6 mmφ × 250 mm)
Eluent: Acrylonitrile / 0.1% by mass phosphoric acid aqueous solution Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer

The lower limit of the fluorine atom content in the [A] polymer and the [B] polymer is preferably 1% by mass, more preferably 2% by mass, further preferably 4% by mass, and particularly preferably 7% by mass. On the other hand, as an upper limit of the said content rate, 60 mass% is preferable, 40 mass% is more preferable, and 30 mass% is further more preferable. Here, the fluorine atom content (% by mass) of the polymer can be calculated from the structure of the polymer determined by ¹³ C-NMR spectrum measurement.

([A] Polymer and [B] Polymer Synthesis Method)
The [A] polymer and the [B] polymer are obtained by polymerizing monomers corresponding to predetermined respective structural units in a suitable polymerization reaction solvent using a polymerization initiator such as a radical polymerization initiator. Can be manufactured. As a specific synthesis method, for example, a method of dropping a solution containing a monomer and a radical polymerization initiator into a polymerization reaction solvent or a solution containing a monomer to cause a polymerization reaction, a solution containing a monomer, , A method of dropping a solution containing a radical polymerization initiator separately into a polymerization reaction solvent or a solution containing a monomer to cause a polymerization reaction, a plurality of types of solutions containing each monomer, and initiation of radical polymerization Examples thereof include a method in which a solution containing an agent is dropped into a solution containing a polymerization reaction solvent or a monomer separately to cause a polymerization reaction.

Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropylene). Pionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), azo radical initiators such as

dimethyl

2,2′-azobisisobutyrate; benzoyl peroxide, t-butyl hydroperoxide, And peroxide radical initiators such as cumene hydroperoxide. Of these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred as the radical polymerization initiator, and AIBN is more preferred. These radical initiators can be used alone or in combination of two or more.

As the solvent used for the polymerization, for example, the same solvent as that which may be contained in the chemical amplification resist material described later can be used.

The lower limit of the reaction temperature in the polymerization is preferably 40 ° C, more preferably 50 ° C. On the other hand, the upper limit of the reaction temperature is preferably 150 ° C, more preferably 120 ° C. The lower limit of the reaction time in the polymerization is preferably 1 hour. On the other hand, the upper limit of the reaction time is preferably 48 hours, more preferably 24 hours.

[A] polymer and [B] polymer are preferably recovered by a reprecipitation method. That is, after completion of the reaction, the target polymer is recovered as a powder by introducing the reaction solution into a reprecipitation solvent. As the reprecipitation solvent, alcohols, alkanes and the like can be used singly or in combination of two or more. In addition to the reprecipitation method, the polymer can be recovered by removing low molecular components such as monomers and oligomers by a liquid separation operation, a column operation, an ultrafiltration operation, or the like.

[(2) component and (3) component]
The component (2) is a component that generates a radiation-sensitive sensitizer and an acid upon exposure (radiation irradiation). The component (3) is a component that is relatively basic with respect to the acid generated by the component (2). The component (2) comprises (a) a radiation-sensitive acid-sensitizer generator, (b) a radiation-sensitive sensitizer generator, and (c) a radiation-sensitive acid generator. Component a), component (a) and component (b), component (a) and component (c), component (b) and component (c), or all components (a) to (c) are contained. The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group (hereinafter also referred to as “[C1] compound”). The (a) radiation-sensitive acid-sensitizer generator or the (c) radiation-sensitive acid generator may have one or more [C1] compounds.

When the component (2) is contained as a structural unit of the polymer of the polymer component (1), the first compound having a radiation-sensitive acid generating group that the component (a) or (c) has Further, it may be contained in the form of a radiation-sensitive acid generating group in which one hydrogen of C—H bond contained in the compound is extracted.

(3) The component is relatively basic with respect to the acid generated by the component (2). Moreover, (3) component contains the 2nd compound (henceforth "[C2] compound") which is (d) a radiation sensitive photodegradable base. The (d) radiation-sensitive photodegradable base may have one or more [C2] compounds.

When the component (3) is contained as a structural unit of the polymer of the polymer component (1), the second compound having a radiation-sensitive photodegradable base included in the component (d) is contained in the compound. It may be contained in the form of a radiation-sensitive photodegradable base from which one hydrogen atom of C—H bond contained in is extracted.

(D) The radiation-sensitive photodegradable base is irradiated with the second radiation when the first radiation is irradiated and the second radiation is not irradiated, and after the first radiation is irradiated. In this case, when the basic component of the acid generated by the component (2) is lost and only the second radiation is irradiated without irradiating the first radiation, the component (2) is generated. Retains basicity. However, the radiation-sensitive photodegradable base is a compound represented by the following formula (x), and the reduction potential of M ⁺ in the following formula (x) is higher than the reduction potential of the triphenylsulfonium cation.

In the formula (x), A ⁻ is a monovalent anion. M ⁺ is a monovalent onium cation.

Below replacing the monovalent anion represented by the nonafluorobutanesulfonate anion ^- e.g. the radiation sensitive light decay base is a compound represented by the formula (x), A in the formula (x) A monovalent onium cation represented by M ⁺ in the following formula (z) when the compound represented by the formula (z) is compared with triphenylsulfonium nonafluorobutane sulfonate represented by the following formula (y) The reduction potential of is higher than the reduction potential of the triphenylsulfonium cation.

In the above formula (z), M + is synonymous with the formula (x).

(D) The radiation-sensitive photodegradable base may be in the form of a group that is included as a structural unit of the polymer (1) polymer component and incorporated as part of the polymer. In this case, (d) the radiation-sensitive photodegradable base exists in a form in which a group obtained by removing one hydrogen atom from the [C2] compound is bonded to the polymer, and the radiation-sensitive photodegradable base is represented by the following formula (x ') However, the reduction potential of the monovalent onium cation represented by M ⁺ in the following formula (x ′) is higher than the reduction potential of the triphenylsulfonium cation.

', A represents the formula (x)' ^- is a monovalent group comprising a monovalent anion. M ⁺ is synonymous with the formula (x). * Shows the site | part couple | bonded with a polymer.

For example the radiation-sensitive light decay bases 'is represented by the above formula (x the formula (x)' A in) ^- was replaced by a monovalent octafluorobutane sulfonate group a group containing a monovalent anion represented by The group represented by the above formula (z ′) and the triphenylsulfonium octafluorobutanesulfonate group represented by the following formula (y ′) are represented by M ⁺ in the following formula (z ′) when compared. The reduction potential of the monovalent onium cation is higher than the reduction potential of the triphenylsulfonium cation.

In the formula (y ′), * represents a site bonded to the polymer.

In formula (z ′), M ⁺ has the same meaning as in formula (x). * Is synonymous with the formula (y ′).

Since the chemical amplification resist material contains the above components, high sensitivity and excellent lithography performance can be obtained when radiation having a wavelength of 250 nm or less such as EUV is used as pattern exposure light. Although the reason why the chemically amplified resist material has the above-described configuration provides the above-mentioned effect is not clear, it can be presumed as follows, for example. That is, although a sensitizer is generated in the pattern exposure unit, exposure to the second radiation in this state allows the photodisintegrating base to receive energy from the sensitizer more efficiently and promote decomposition. Thus, it is considered that excellent lithography performance can be obtained by improving the sensitivity and the contrast of generation of acid between the exposed and unexposed portions in pattern exposure.

Further, (d) the reduction potential of the monovalent onium cation represented by M ⁺ of the radiation-sensitive photodegradable base is higher than the reduction potential of the triphenylsulfonium cation under the above conditions. The decomposition of the radiation-sensitive photodisintegratable base is promoted, and the contrast of acid generation between the exposed and unexposed areas in pattern exposure is improved.

When the component (2) is a component different from the (1) polymer component, the lower limit of the content of the component (2) with respect to the total solid content of the chemically amplified resist material is preferably 10% by mass, and 15% by mass. % Is more preferable. On the other hand, the upper limit of the content is preferably 40% by mass, and more preferably 35% by mass. (2) By making content of a component into the said range, the sensitivity and lithography performance of the said chemically amplified resist material can be improved more. “Content of (2) component” means the total content of components different from (1) the polymer component among the (2) components.

When the component (3) is a component different from the (1) polymer component, the lower limit of the amount of the (d) radiation-sensitive photodegradable base to 100 parts by mass of the polymer component (1) is 0.1. Part by mass is preferable, and 1 part by mass is more preferable. On the other hand, as an upper limit of the said compounding quantity, 50 mass parts is preferable and 30 mass parts is more preferable. "Content of (3) component" means the total content of components different from (1) the polymer component among the (3) components.

(D) When a radiation-sensitive photodegradable base is contained as a structural unit of the polymer of (1) polymer component, (d) (d) radiation-sensitive photodegradable with respect to 1 mol of the polymer component. As a minimum of the content rate of a base, 0.01 mol is preferred, 0.02 mol is more preferred, and 0.1 mol is still more preferred. On the other hand, the upper limit of the content ratio is preferably 0.5 mol, more preferably 0.3 mol.

If the blending amount or content ratio is smaller than the lower limit, the sensitivity may decrease. On the contrary, when the said compounding quantity or content rate exceeds the said upper limit, there exists a possibility that it may become difficult to form a resist material film, and there exists a possibility that the rectangularity in the cross-sectional shape of a resist pattern may fall.

([C1] compound and [C2] compound)
The compound [C1] includes a first onium cation (hereinafter also referred to as “cation (I)”) and a first anion (hereinafter also referred to as “anion (I)”). [C2] The compound may include a second onium cation (hereinafter also referred to as “cation (II)”) and a second anion (hereinafter also referred to as “anion (II)”) different from the anion (I). . The cation (I) and the cation (II) are preferably onium cations.

(Cation)
The cation (I) and the cation (II) are onium cations, and the energy required for reducing the cation (I) and the cation (II) is both −1.2 eV (using a standard hydrogen electrode) or more. preferable. The reduction potential can be measured by cyclic voltammetry. The energy required for reducing the cation (I) and the cation (II) is both set to −1.2 eV or more, so that the [C1] compound and the [C2] compound are decomposed at the pattern exposure portion during the second radiation irradiation. Can be further promoted.

The lower limit of the reduction potential of the cation (I) and the cation (II) is preferably −1.2V, more preferably −1.0V, and further preferably −0.9V. . On the other hand, the upper limit of the reduction potential is preferably 0.0 V, more preferably -0.2 V. If the reduction potential is smaller than the lower limit, the strength of the acid generated is insufficient, and the shape of the pattern formed may be poor. On the other hand, when the reduction potential exceeds the upper limit, the strength of the generated acid becomes excessive, and the acid may easily diffuse to the pattern unexposed area.

The lower limit of the energy released when reduced to the cation (I) and cation (II) radicals is preferably 5.0 eV, more preferably 5.1 eV, and even more preferably 5.2 eV. If the energy to be released is smaller than the lower limit, the amount of acid generated is insufficient, and the shape of the pattern formed may be poor. On the other hand, the upper limit of the released energy is preferably 6.0 eV, more preferably 5.9 eV, and even more preferably 5.8 eV. If the energy released exceeds the upper limit, the stability of the acid diffusion controller may be reduced.

It is more preferable that the cation (I) and the cation (II) have the same structure. When the cation (I) and the cation (II) have the same structure, the lithography performance can be further improved.

The lower limit of the total content of the cation (I) and the cation (II) with respect to all onium cations in the chemically amplified resist material is preferably 80 mol%, more preferably 85 mol%, and even more preferably 90 mol%. preferable. By making the total content rate of the said cation (I) and the said cation (II) into the said range, the sensitivity and lithography performance of the said chemically amplified resist material can be improved more.

As the cation (I) and the cation (II), for example, a monovalent onium cation represented by X ⁺ is used. Examples of the monovalent onium cation represented by X ⁺ include cations represented by the following formulas (X-1), (X-2), (X-3) and (X-4) (hereinafter referred to as “ Cation (X-1) "and" cation (X-2) ").

(Anion (I))
Anion (I) and anion (II) are different anions.

The logarithmic value (pKa) of the reciprocal of the acid dissociation constant of the acid generated by the [C1] compound is smaller than the pKa of the acid generated by the [C2] compound. The [C1] compound having a smaller pKa of the generated acid functions as (1) an acid generating compound that makes the polymer component soluble or insoluble in the developer. In addition, the [C2] compound having a larger pKa of the generated acid functions as an acid diffusion controller.

The upper limit of the pKa of the acid generated from the [C1] compound is preferably 0, more preferably -0.5. Further, the lower limit is preferably −7, more preferably −5. [C2] The upper limit of the pKa of the acid generated from the compound is preferably 11.0, and more preferably 10.5. Moreover, as said minimum, 0 is preferable, 1 is more preferable, and 2 is further more preferable. By setting the pKa of the acid within the above range, more excellent lithography performance can be exhibited. The pKa is a calculated value obtained by ACD / ChemSketch (ACD / Labs 8.00 Release Product Version: 8.08).

Examples of the anion (I) and the anion (II) include a sulfonate anion, a carboxylate anion, a bis (alkylsulfonyl) amide anion, and a tris (alkylsulfonyl) methide anion.

The anion (I), which has a small logarithmic value (pKa) of the reciprocal of the acid dissociation constant of the generated acid and functions as an anion of the [C1] compound that is an acid generating compound, is represented by the following general formulas (XX), (XXI) and An anion of an acid represented by (XXII) is preferred, and an anion of an acid represented by the following general formula (XX) is more preferred.

In the general formulas (XX), (XXI) and (XXII), R ¹⁸ to R ²¹ each independently represents an organic group. Examples of the organic group include an alkyl group, an aryl group, and a group in which a plurality of these groups are linked. As the substituent bonded to the 1-position of the organic group, an alkyl group substituted with a fluorine atom or a fluoroalkyl group and a phenyl group substituted with a fluorine atom or a fluoroalkyl group are preferable. When the organic group has a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by exposure increases, and the sensitivity tends to be improved. However, it is preferable that the terminal substituent not on the side of the bond of the organic group does not contain a fluorine atom.

As the [C1] compound having a small logarithmic value (pKa) of the reciprocal of the acid dissociation constant of the generated acid and functioning as an acid generating compound, those represented by the following formula (1) are preferable. That is, the acid anion of the [C1] compound that functions as an acid generating compound preferably has a structure represented by the following formula (1).

In the above formula (1), R ^p1 is a monovalent group containing a ring structure having 6 or more ring members. R ^p2 is a divalent linking group. R ^p3 and R ^p4 are each independently a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. n ^p1 is an integer of 0 to 10. n ^p2 is an integer of 0 to 10. n ^p3 is an integer of 1 to 10. When n ^p1 is 2 or more, the plurality of R ^p2 may be the same or different. When n ^p2 is 2 or more, the plurality of R ^p3 may be the same or different, and the plurality of R ^p4 may be the same or different. When n ^p3 is 2 or more, the plurality of R ^p5 may be the same or different, and the plurality of R ^p6 may be the same or different. X ⁺ is cation (I) and cation (II).

Here, the “number of ring members” refers to the number of atoms constituting a ring of an aromatic ring structure, aromatic heterocyclic structure, alicyclic structure and aliphatic heterocyclic structure, and in the case of a polycyclic ring structure, The number of atoms that make up the ring. The “hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “hydrocarbon group” may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The “chain hydrocarbon group” refers to a hydrocarbon group that does not include a cyclic structure but includes only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The term “alicyclic hydrocarbon group” refers to a hydrocarbon group that includes only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic group. Includes both hydrocarbon groups. However, it is not necessary to be composed only of the alicyclic structure, and a part thereof may include a chain structure. “Aromatic hydrocarbon group” refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic structure.

Examples of the [C1] compound and the [C2] compound include 4,4′-di (t-butylphenyl) iodonium 6- (adamantan-1-ylcarboxyoxy) -1,1,2,2-tetrafluorohexane- 1-sulfonate, 4,4′-di (t-butylphenyl) iodonium 4-trifluoromethyl salicylate, 4,4′-di (t-butylphenyl) iodonium adamantane-1-yloxycarbonylcarboxylate, 4 , 4′-di (t-butylphenyl) iodonium 1,2 di (cyclohexyloxycarbonyl) ethane-1-sulfonate, 4,4′-di (t-butylphenyl) iodonium trifluoromethanesulfonate, 4,4′-di (T-butylphenyl) iodonium nonafluoro-n-butanesulfonate, 4, '-Di (t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4,4'-di (t-butylphenyl) ) Iodonium perfluoro-n-octanesulfonate, 4,4'-di (t-butylphenyl) iodonium 4-methylsulfonylphenyldiphenylsulfonium 1,2 di (cyclohexyloxycarbonyl) ethane-1-sulfonate, 4-methylsulfonylphenyl Diphenylsulfonium 4-trifluoromethyl salicylate, 4-methylsulfonylphenyl diphenylsulfonium 6- (adamantan-1-ylcarboxyoxy) -1,1,2,2-tetrafluorohexane-1-sulfonate, 4-methylsulfonyl Phenyldiphenyl Rufonium adamantane-1-yloxycarbonylcarboxylate, 4-methylsulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methylsulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methylsulfonylphenyldiphenylsulfonium 2-bicyclo [2 2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methylsulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, and the like.

Examples of the [C1] compound and the [C2] compound include, for example, JP-A-2016-054772, JP-A-2014-063160, JP-A-2014-191061, JP-A-2006-215202, and JP-A-2006. And the compounds described in JP-A No. -215271 and JP-A No. 2004-004557. Specific examples of the [C1] compound and [C2] compound include compounds represented by the following formulas (C-1-1) to (C-2-7) (hereinafter referred to as “compound (C-1-1)”). To (C-2-7) ”) and the like.

The lower limit of the content of the [C1] compound with respect to 100 parts by mass of the component (a) or the component (c) is preferably 50% by mass, and more preferably 60% by mass. On the other hand, as an upper limit of content of the said [C1] compound, 90 mass% is preferable and 80 mass% is more preferable.

Specific examples of the [C2] compound include JP-A-2016-045472, JP-A-2014-063160, JP-A-2014-191061, JP-A-2006-215202, JP-A-2006-215271. Among the compounds described in JP-A-2004-004557, compounds having a reduction potential higher than the reduction potential of the triphenylsulfonium cation can be selected and used. It preferably contains a group having an electron-withdrawing substituent as defined in paragraph [0045] of JP-A-2004-004557. Examples of the electron-withdrawing substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, nitro group, arylcarbonyl group, and alkylcarbonyl group.

The lower limit of the content of the [C2] compound with respect to 100 parts by mass of the component (a) or the component (c) is preferably 5% by mass, and more preferably 10% by mass. On the other hand, the upper limit of the content is preferably 50% by mass, and more preferably 40% by mass. By setting the contents of the compound having a smaller pKa of the generated acid and the compound having a larger pKa within the above range, the sensitivity and lithography performance of the chemically amplified resist material can be further improved.

((A) Radiation sensitive acid-sensitizer generator)
(A) The radiation-sensitive acid-sensitizer generator is irradiated with a first radiation that is a radiation having a wavelength of 250 nm or less, such as KrF, ArF, EUV, or an electron beam, and is a radiation having a wavelength exceeding 250 nm. When no second radiation is irradiated, an acid and a radiation-sensitive sensitizer that absorbs the second radiation are generated, and only the second radiation is not irradiated with the first radiation. When irradiated, the acid and radiation-sensitive sensitizer are not substantially generated.

Examples of the [C1] compound that serves as the radiation sensitive acid-sensitizer generator (a) include, for example, the cation portion or the anion portion of the onium salt compound among the above-mentioned [C1] compound and [C2] compound. And (b) a compound substituted with a radiation-sensitive sensitizer generating compound described later. Moreover, as an onium salt compound, a sulfonium salt compound, an iodonium salt compound, etc. are mentioned, for example.

Examples of the cation (I) and cation (II) in the above [C1] compound include 4,4'-di (t-butylphenyl) iodonium cation and 4-methylsulfonylphenyldiphenylsulfonium cation.

(A) The radiation-sensitive acid-sensitizer generator may have a compound other than the above [C1] compound and [C2] compound, and other than the [C1] compound and the [C2] compound (a ) Examples of the radiation sensitive acid-sensitizer generator include other onium salt compounds. Examples of the onium salt compound include a sulfonium salt compound, a tetrahydrothiophenium salt compound, and an iodonium salt compound.

(A) The radiation-sensitive acid-sensitizer generator may be in the form of (1) a group included as a polymer structural unit of a polymer component and incorporated as part of the polymer. In this case, (a) the radiation-sensitive acid-sensitizer generator is present in a form in which a group obtained by removing one hydrogen atom from the above compound is bonded to the polymer.

When (a) the radiation-sensitive acid-sensitizer generator is a component different from (1) the polymer component, (a) generation of (a) radiation-sensitive acid-sensitizer with respect to 100 parts by mass of the polymer component As a minimum of the compounding quantity of an agent, 0.005 mass part is preferred and 0.1 mass part is more preferred. On the other hand, as an upper limit of the said compounding quantity, 50 mass parts is preferable and 30 mass parts is more preferable.

When (a) a radiation-sensitive acid-sensitizer generator is included as a structural unit of the polymer of (1) the polymer component, (a) (a) the radiation-sensitive acid per mole of the polymer component -The lower limit of the content of the sensitizer generator is preferably 0.001 mol, more preferably 0.002 mol, and still more preferably 0.01 mol. On the other hand, the upper limit of the content ratio is preferably 0.5 mol, more preferably 0.3 mol.

((B) Radiation-sensitive sensitizer generating agent)
(B) The radiation-sensitive sensitizer generating agent generates a radiation-sensitive sensitizer that absorbs the second radiation when irradiated with the first radiation and not irradiated with the second radiation. And a component that does not substantially generate the radiation-sensitive sensitizer when the first radiation is not irradiated and only the second radiation is irradiated. It is different from the body generator.

In the chemically amplified resist material, (b) the chemical structure of the radiation-sensitive sensitizer generating agent is converted by direct or indirect reaction upon irradiation with the first radiation, and acid is generated upon irradiation with the second radiation. Produce an auxiliary radiation-sensitive sensitizer. Since this radiation-sensitive sensitizer easily absorbs the second radiation as compared with the (b) radiation-sensitive sensitizer generating agent, the radiation-sensitive sensitization is performed when pattern exposure is performed with the first radiation. The absorption amount of the second radiation is greatly different between the exposed portion where the body is generated and the non-exposed portion where the radiation-sensitive sensitizer is not generated, and the contrast of the absorption amount is easily obtained.

Necessary to oxidize the value of energy (E ^* ) necessary to excite the radiation-sensitive sensitizer that absorbs the second radiation and the radiation-sensitive sensitizer that absorbs the second radiation. Of the photosensitized energy transfer obtained from the following formula (I) based on the value of the effective energy (E ^{Oxi (PS)} ) and the value of the energy necessary to reduce the second compound (E ^{Red (Qu)} ) The free energy (ΔG ^(Qu) ) is preferably 0 kcal / mol or less.

ΔG ^(Qu) = (E ^{Oxi (PS)} −E ^{Red (Qu)} ) −E ^* (I)

When ΔG ^(Qu) is 0 kcal / mol or less, excitation by the second radiation exposure of the radiation-sensitive sensitizer and electron transfer to the radiation-sensitive disintegrating base, that is, decomposition, while the exciter is oxidized are performed. Since this is thermodynamically advantageous, it is possible to further improve the chemical contrast of the latent image of the acid between the exposed portion and the non-exposed portion.

Necessary to oxidize the value of energy (E ^* ) necessary to excite the radiation-sensitive sensitizer that absorbs the second radiation and the radiation-sensitive sensitizer that absorbs the second radiation. Of the photosensitized energy transfer obtained from the following formula (II) based on the value of the effective energy (E ^{Oxi (PS)} ) and the value of the energy necessary to reduce the first compound (E ^{Red (PAG)} ) The free energy (ΔG ^(PAG) ) is preferably 0 kcal / mol or less.

ΔG ^(PAG) = (E ^{Oxi (PS)} −E ^{Red (PAG)} ) −E ^* (II)

When ΔG ^(PAG) is 0 kcal / mol or less, excitation of the radiation-sensitive sensitizer by the second radiation exposure and electron transfer to the radiation-sensitive acid generator while the exciter is oxidized, that is, acid generation Since this is thermodynamically advantageous, the chemical contrast of the latent image of the acid between the exposed area and the non-exposed area can be further improved.

Here, in the above formulas (1) and (2), ΔG ^(Qu) and ΔG ^(PAG) are changes in the free energy of the cast.
The reduction potential is 2000_03_Seiji Nagahara_Ph_D_Thesis. pdf, 3.2.3. Measure the reduction potential by cyclic voltammetry under an Ar atmosphere using a measurement of reduction potential of acid generator, using platinum as the working electrode, platinum wire as the counter electrode, and a saturated calomel electrode (SCE) as the reference electrode. be able to. In addition, since an acid generator decomposes | disassembles by reduction | restoration, it is irreversible and only a reduction peak is observed.

(B) The radiation-sensitive sensitizer generator is preferably a carbonyl compound having a carbonyl group that absorbs the second radiation when irradiated with the first radiation. Examples of the carbonyl compound include aldehyde, ketone, carboxylic acid, carboxylic acid ester and the like. The above reaction causes a shift in the peak of the absorption wavelength of radiation only in the (b) radiation-sensitive sensitizer generating agent in the pattern exposure portion. Therefore, if pattern exposure is performed with radiation having a wavelength that can be absorbed only by the pattern exposure portion after pattern exposure, only the pattern exposure portion can be selectively sensitized. (B) As the radiation-sensitive sensitizer generator, an alcohol compound represented by the following formula (VI) is more preferable, and a secondary alcohol compound may be used. In the present specification, the alcohol compound does not mean only a compound having an alcoholic hydroxyl group, but includes a ketal compound, an acetal compound, an orthoester compound, etc., in which a hydrogen atom of the alcoholic hydroxyl group is substituted. May be. (B) When the radiation-sensitive sensitizer generator is a ketal compound or an acetal compound, heating is performed after pattern exposure and before batch exposure in order to accelerate the hydrolysis reaction to the carbonyl compound by the acid catalyst generated by pattern exposure. May be.

In formula (VI), R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom; phenyl group; naphthyl group; anthracenyl group; alkoxy group having 1 to 5 carbon atoms; alkylthio group having 1 to 5 carbon atoms A phenoxy group; a naphthoxy group; an anthracenoxy group; an amino group; an amide group; a halogen atom; a linear, branched or cyclic saturated or unsaturated hydrocarbon having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms); A group (preferably an alkyl group); a linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms), 1 carbon atom An alkoxy group having 1 to 5 carbon atoms, substituted with an alkoxy group having 5 to 5 alkoxy groups, an amino group, an amide group, or a hydroxyl group; a linear or branched group having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms) Alkylthio having 1 to 5 carbon atoms substituted with a branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group), an alkoxy group having 1 to 5 carbon atoms, an amino group, an amide group, or a hydroxyl group Group: a phenoxy group substituted by an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, an amino group, an amide group, or an alkyl group having 1 to 5 carbon atoms; 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms) A phenyl group substituted with a linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group), an alkoxy group having 1 to 5 carbon atoms, an amino group, an amide group, or a hydroxyl group; A naphthoxy group substituted by an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an amino group, an amide group, or a hydroxyl group; An anthracenoxy group substituted with a alkoxy group, an alkyl group having 1 to 5 carbon atoms, an amino group, an amide group, or a hydroxyl group; an alkoxy group having 1 to 5 carbon atoms, a phenoxy group, a naphthoxy group, an anthracenoxy group, an amino group, an amide A linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms) substituted with a group or a hydroxyl group; or A carbonyl group to which an alkyl group having 1 to 12 carbon atoms is bonded is shown. The alcohol compound may be a thiol compound in which the alcoholic hydroxyl group (hydroxyl group) in formula (VI) is a thiol group. In the above formula (VI), the hydrogen atom of the hydroxyl group or thiol group is a phenyl group; a halogen atom; a straight-chain, branched-chain or cyclic saturated group having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms) or An unsaturated hydrocarbon group (preferably an alkyl group); or a linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms). ), An alkoxy group having 1 to 5 carbon atoms, or a phenyl group substituted with a hydroxyl group. In the formula, any two or more groups of R ⁸ , R ⁹ and R ¹⁰ are each a single bond or a double bond, or —CH ₂ —, —O—, —S—, —SO ₂ —, — SO ₂ NH—, —C (═O) —, —C (═O) O—, —NHCO—, —NHC (═O) NH—, —CHR ^g —, —CR ^g ₂ —, —NH— or A ring structure may be formed through a bond containing —NR ^g —. R ^g is a phenyl group; a phenoxy group; a halogen atom; a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms) (preferably an alkyl group). ); A phenoxy group substituted with an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 5 carbon atoms; or a straight chain having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms), A phenyl group substituted with a branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group), an alkoxy group having 1 to 5 carbon atoms, or a hydroxyl group. R ⁸ , R ⁹ and R ¹⁰ are preferably each independently substituted with a hydrogen atom; a phenyl group; a phenoxy group; an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 5 carbon atoms. Or a phenyl group substituted with an alkoxy group having 1 to 5 carbon atoms or a hydroxyl group.

In addition, as a ketal compound or acetal compound in which the hydrogen atom of the hydroxyl group in formula (VI) is substituted, a compound represented by the following formula (XXXVI) is preferable. That is, (b) the radiation-sensitive sensitizer generating agent may be a compound represented by the following formula (XXXVI). When either one of R ^{9 and} R ¹⁰ is a hydrogen atom, it can be said that the compound represented by the following formula (XXXVI) is an acetal compound.

Wherein (XXXVI), ^{R 9} and ^{R 10} are the same meanings as ^{R 9} and ^{R 10} in formula (VI). R ⁹ and ^{R 10,} may form a similarly ring structure with ^{R 9} and ^{R 10} in formula (VI). In formula (XXXVI), R ²³ and R ²⁴ are each independently a phenyl group; a halogen atom; a linear, branched or cyclic saturated group having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms). Or an unsaturated hydrocarbon group (preferably an alkyl group); or a linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms). Group), an alkoxy group having 1 to 5 carbon atoms, or a phenyl group substituted with a hydroxyl group. R ²³ and R ²⁴ are a single bond, a double bond, —CH ₂ —, —O—, —S—, —SO ₂ —, —SO ₂ NH—, —C (═O) —, —C (= A ring structure may be formed through a bond containing O) O—, —NHCO—, NHC (═O) NH—, —CHR ^g —, —CR ^g ₂ , —NH— or —NR ^g —. . R ^g has the same meaning as ^{R g} in the formula (VI). The ketal compound or acetal compound may be a thioketal compound or a thioacetal compound in which the oxygen atom bonded to R ²³ and / or R ²⁴ in formula (XXXVI) is replaced with sulfur.

A ketal compound and an acetal compound can be obtained by reacting a carbonyl compound with an alcohol. The above reaction can be referred to as a reaction for protecting a carbonyl group that contributes to radiosensitization, and R ²³ and R ²⁴ in the above formula (XXXVI) can be referred to as a protecting group for a carbonyl group. In this case, the reaction in which (b) the radiation-sensitive sensitizer generator becomes a radiation-sensitive sensitizer by radiation or the like can be referred to as a deprotection reaction. Examples of the reactivity of the protecting group (ease of deprotection reaction) are shown below. The reactivity of the protecting group increases as it goes to the right and decreases as it goes to the left. For example, when a methoxy group is used as a protecting group for a carbonyl group, the reactivity of the deprotection reaction is high, and the deprotection reaction tends to proceed under an acid catalyst even at room temperature. As described above, the deprotection reaction proceeds at room temperature, so that there is an advantage that blurring of the image can be prevented. On the other hand, if a deprotection reaction occurs in a pattern unexposed portion at the time of pattern exposure and a radiation-sensitive sensitizer is generated, the contrast of the resist may be deteriorated. In order to prevent the formation of a radiation-sensitive sensitizer in the pattern unexposed area, a protecting group can be selected so as to increase the activation energy of the deprotection reaction (decrease the reactivity of the protecting group). From the viewpoint of lowering the reactivity of the protecting group, a cyclic protecting group in which R ²³ and R ^{24 in} formula (XXXVI) are bonded to each other to form a ring structure is more preferable. Examples of the ring structure include a 6-membered ring and a 5-membered ring, and a 5-membered ring is preferable. When a protective group having low reactivity is used, the resist material preferably contains a first scavenger described later, and the resist material film is preferably baked after pattern exposure and before batch exposure. By performing baking, unnecessary acid in the unexposed portion of the pattern is neutralized by the capturing agent, and the contrast of the latent image can be improved. The baking can compensate for the decrease in the reactivity of the protecting group, and the roughness of the latent image of the acid in the resist material film can be reduced by the diffusion of the substance by baking.

The ketal type (b) radiation-sensitive sensitizer generating agent may be a compound represented by the following formulas (XXVII) to (XXX).

Wherein ^{(XXVII) ~ (XXX),} R 23 and ^{R 24} are the same meanings as ^{R 23} and ^{R 24} in the formula (XXXVI). In formulas (XXVII) to (XXX), the hydrogen atom of the aromatic ring may be substituted with an alkoxy group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms, and the aromatic ring is bonded to another aromatic ring Thus, a naphthalene ring or an anthracene ring may be formed. R ²⁵ represents an alkyl group having 1 to 5 carbon atoms. (B) When the compounds represented by the above formulas (XXVII) to (XXX) are used as the radiation-sensitive sensitizer generating agent, (b) from the radiation-sensitive sensitizer generating agent to the radiation-sensitive sensitizer and The shift of the absorption wavelength of the radiation at that time is larger, and a more selective sensitization reaction can be caused in the pattern exposure part.

In addition, as an orthoester compound by which the hydrogen atom of the hydroxyl group in Formula (VI) was substituted, the compound represented by a following formula (XLVI) is preferable. That is, (b) the radiation-sensitive sensitizer generating agent may be a compound represented by the following formula (XLVI).

Wherein (XLVI), ^{R 9} has the same meaning as ^{R 9} in the formula (VI). In the formula (XLVI), R ³⁸ to R ⁴⁰ are each independently a phenyl group; a halogen atom; a linear, branched or cyclic saturated group having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms). Or an unsaturated hydrocarbon (preferably an alkyl group); or a linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms). ), A phenyl group substituted with an alkoxy group having 1 to 5 carbon atoms or a hydroxyl group. R ³⁸ to R ⁴⁰ are each a single bond or a double bond, or —CH ₂ —, —O—, —S—, —SO ₂ —, —SO ₂ NH—, —C (═O) —, —C A ring structure is formed through a bond including (═O) O—, —NHCO—, —NHC (═O) NH—, —CHR ^g —, —CR ^g ₂ , —NH— or —NR ^g —. May be. R ^g has the same meaning as ^{R g} in the formula (VI).

The ortho ester compound is decomposed by a deprotection reaction in pattern exposure, and becomes, for example, a carboxylic acid ester or carboxylic acid containing a carbonyl group. As the ortho ester compound, the carboxyl group part of the radiation-sensitive sensitizer having a carboxyl group is OBO (for example, 4-methyl 2,6,7-trioxabicyclo [2.2.2] octane-1-yl). The OBO ester compound represented by the following formula (XLVII) substituted (protected) with is preferable. The (b) radiation-sensitive sensitizer generating agent having a carboxyl group protected with OBO generates carboxylic acid by an acid catalyst generated during pattern exposure, shifts the absorption wavelength of radiation, and radiation-sensitive sensitization during batch exposure. Work as a body. (B) Since the carboxylic acid is generated from the radiation-sensitive sensitizer generating agent, the polarity of the resist changes, for example, from nonpolar to polar in the pattern exposure portion. For this reason, the ortho ester compound also functions as a dissolution accelerator in the development process, and contributes to an improvement in resist contrast. (B) When the radiation-sensitive sensitizer generator contains an OBO ester compound, it is possible to simultaneously generate the radiation-sensitive sensitizer and cause a polarity change reaction.

In formula (XLVII), R ⁴¹ and R ⁴² each independently represent a hydrogen atom; a phenyl group; a naphthyl group; an anthracenyl group; a phenoxy group; a naphthoxy group; an anthracenoxy group; an amino group; A linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 30 (preferably 1 to 5 carbon atoms); an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, amino Group, amide group, or phenoxy group substituted with an alkyl group having 1 to 5 carbon atoms; linear, branched or cyclic saturated or unsaturated having 1 to 30 carbon atoms (preferably 1 to 5 carbon atoms) A phenyl group substituted by a hydrocarbon group (preferably an alkyl group), an alkoxy group having 1 to 5 carbon atoms, an amino group, an amide group, or a hydroxyl group; carbon A naphthoxy group substituted by an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or a hydroxyl group; an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an amino group, an amide group, Or an anthracenoxy group substituted with a hydroxyl group; an alkoxy group having 1 to 5 carbon atoms, a phenoxy group, a naphthoxy group, an anthracenoxy group, an amino group, an amide group, or a hydroxyl group, substituted with 1 to 30 carbon atoms (preferably A linear, branched or cyclic saturated or unsaturated hydrocarbon group (preferably an alkyl group) having 1 to 5 carbon atoms; or a carbonyl group to which an alkyl group having 1 to 12 carbon atoms is bonded. R ⁴¹ and R ⁴² are preferably each independently a hydrogen atom; a phenyl group; a phenoxy group; a phenoxy group substituted with an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 5 carbon atoms. Or a phenyl group substituted with an alkoxy group having 1 to 5 carbon atoms or a hydroxyl group;

(B) Examples of the radiation-sensitive sensitizer generating agent include compounds represented by the following formulas. These compounds are alcohol compounds in which the hydrogen atom of the alcoholic hydroxyl group is not substituted, and change into a ketone compound by a reaction during pattern exposure.

The following compounds are examples of ketal compounds or acetal compounds in which the carbonyl group of the radiation-sensitive sensitizer is protected. These compounds become radiation-sensitive sensitizers containing ketones in the pattern exposure part by the catalytic action of the acid generated by pattern exposure.

The following compound is an example of an ortho ester compound having a carbon atom substituted with three alkoxy groups.

The ortho ester compound is deprotected by an acid catalyst generated during pattern exposure to produce an ester having a carbonyl group (methyl carboxylate in the following example).

In the following chemical formula, the carboxyl group part of the radiation-sensitive sensitizer having a carboxyl group is represented by OBO (for example, 4-methyl-2,6,7-trioxabicyclo [2.2.2] octane-1-yl). It is an example of the OBO ester compound which is a protected derivative.

The OBO ester compound generates the following carboxylic acid by an acid catalyst generated during pattern exposure.

Examples of the radiation-sensitive sensitizer generated by exposure from the component (2) (that is, the above-mentioned (a) radiation-sensitive acid-sensitizer generator and (b) radiation-sensitive sensitizer generator) include, for example: Chalcone and derivatives thereof, 1,2-diketone and derivatives thereof, benzoin and derivatives thereof, benzophenone and derivatives thereof, fluorene and derivatives thereof, naphthoquinone and derivatives thereof, anthraquinone and derivatives thereof, xanthene and derivatives thereof, thioxanthene and derivatives thereof, Xanthone and derivatives thereof, thioxanthone and derivatives thereof, cyanine and derivatives thereof, merocyanine and derivatives thereof, naphthalocyanine and derivatives thereof, subphthalocyanine and derivatives thereof, pyrylium and derivatives thereof, thiopyrylium and derivatives thereof, tetraphylline and derivatives thereof, Len and derivatives thereof, spiropyran and derivatives thereof, spirooxazine and derivatives thereof, thiospiropyran and derivatives thereof, oxol and derivatives thereof, azine and derivatives thereof, thiazine and derivatives thereof, oxazine and derivatives thereof, indoline and derivatives thereof, azulene and derivatives thereof Derivatives, azulenium and its derivatives, squarylium and its derivatives, porphyrin and its derivatives, porphyrazine and its derivatives, triarylmethane and its derivatives, phthalocyanine and its derivatives, acridone and its derivatives, coumarin and its derivatives, ketocoumarin and its derivatives, Quinolinone and its derivatives, benzoxazole and its derivatives, acridine and its derivatives, thiazine and its derivatives, benzothiazole and its derivatives, Thiazine and derivatives thereof, benzotriazole and derivatives thereof, perylene and derivatives thereof, naphthalene and derivatives thereof, anthracene and derivatives thereof, phenanthrene and derivatives thereof, pyrene and derivatives thereof, naphthacene and derivatives thereof, pentacene and derivatives thereof, and coronene and derivatives thereof Derivatives and the like. Moreover, it is preferable that the said radiation sensitive sensitizer which generate | occur | produces from said (2) component by exposure contains a carbonyl compound. The carbonyl compound preferably contains ketone, aldehyde, carboxylic acid, ester, amide, enone, carboxylic acid chloride, carboxylic acid anhydride and the like as a carbonyl group. The carbonyl compound is preferably a compound that absorbs radiation on the longer wavelength side exceeding 250 nm from the viewpoint of increasing the contrast of the resist by sufficiently separating the wavelength of radiation at the time of batch exposure from the wavelength of radiation at the time of pattern exposure. Examples of the carbonyl compound include benzophenone derivatives, xanthone derivatives, thioxanthone derivatives, coumarin derivatives, and acridone derivatives. The carbonyl compound may be a naphthalene derivative or an anthracene derivative, or an acridone derivative. In the radiation-sensitive sensitizer, the hydrogen of the aromatic ring is preferably substituted with an electron donating group. When the hydrogen in the aromatic ring of the radiation-sensitive sensitizer is replaced with an electron-donating group, the electron transfer efficiency due to the sensitization reaction during batch exposure is improved, and the resist sensitivity tends to be improved. In addition, (b) the difference between the radiation absorption wavelength of the radiation-sensitive sensitizer and the radiation absorption wavelength of the radiation-sensitive sensitizer can be increased, and the radiation sensitivity can be more selectively at the time of batch exposure. Since the sensitizer can be excited, the contrast of the latent image of the acid in the resist material tends to be improved. Examples of the electron donating group include a hydroxyl group, a methoxy group, an alkoxy group, an amino group, an alkylamino group, and an alkyl group.

Examples of benzophenone and its derivatives include the following compounds.

Examples of thioxanthone and derivatives thereof include the following compounds.

Examples of xanthone and derivatives thereof include the following compounds.

Examples of acridone and its derivatives include the following compounds.

Examples of coumarin and its derivatives include the following compounds.

The radiation-sensitive sensitizer may contain the following compound.

Examples of the radiation-sensitive sensitizer include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 1,2-hydroxy-2-methyl-1-phenyl. Propan-1-one, α-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-hydroxy-2-methyl-1- (4-isopropylphenyl) propanone, 2-hydroxy -2-methyl-1- (4-dodecylphenyl) propanone, 2-hydroxy-2-methyl-1-[(2-hydroxyethoxy) phenyl] propanone, benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4- Methylbenzophenone, 4-methoxyben Phenone, 2-chlorobenzophenone, 4-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone, 2-ethoxycarbonylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, benzophenone tetracarboxylic acid or tetramethyl ester thereof, 4 , 4′-bis (dimethylamino) benzophenone, 4,4′-bis (dicyclohexylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (dihydroxyethylamino) benzophenone, 4- Methoxy-4'-dimethylaminobenzophenone, 4,4'-dimethoxybenzophenone, 4-dimethylaminobenzophenone, 4-dimethylaminoacetophenone, benzyl, anthraquinone, 2-t-butyl Tyranthraquinone, 2-methylanthraquinone, phenanthraquinone, fluorenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2- (dimethylamino) -2-[(4 -Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-hydroxy -2-Methyl- [4- (1-methylvinyl) phenyl] propanol oligomer, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin phenyl ether, benzyldimethyl ketal, acridone Chloroacridone, N-methylacridone, N-butylacridone, N-butyl-chloroacridone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6- Dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, bis- ( 2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzene) Zoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2,6 -Dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6-trimethylbenzoyl) Phenylphosphine oxide, (2,5,6-trimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichloro Thioxa 1-chloro-4-propoxythioxanthone, benzoyldi- (2,6-dimethylphenyl) phosphonate, 1- [4- (phenylthio) phenyl] -1,2-octanedione-2- (O-benzoyloxime), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone-1- (O-acetyloxime), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -3-cyclopentylpropanone-1- (O-acetyloxime), 1- [4- (phenylthio) phenyl] -3-cyclopentylpropane-1,2-dione-2- ( O-benzoyloxime), 2,2-dimethoxy-1,2-diphenylethane-1-one, 1- [4- (2-hydroxyethoxy)- Enyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2- Methyl-propan-1-one, phenylglyoxylic acid methyl ester, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) and the like.

(B) The radiation-sensitive sensitizer generator may be in the form of (1) a group that is included as a polymer structural unit of a polymer component and incorporated as part of the polymer. In this case, (b) the radiation-sensitive sensitizer generator is present in a form in which a group obtained by removing one hydrogen atom from the above compound is bonded to the polymer.

When the (b) radiation-sensitive sensitizer generator is a component different from the (1) polymer component, the blending amount of the (b) radiation-sensitive sensitizer generator with respect to 100 parts by mass of the polymer component (1) Is preferably 0.005 parts by mass, more preferably 0.1 parts by mass. On the other hand, as an upper limit of the said compounding quantity, 50 mass parts is preferable and 30 mass parts is more preferable.

(B) When a radiation-sensitive sensitizer generator is included as a structural unit of the polymer of (1) polymer component, (b) (b) radiation-sensitive sensitizer for 1 mol of the polymer component As a minimum of the content rate of a generating agent, 0.001 mol is preferred, 0.002 mol is more preferred, and 0.01 mol is still more preferred. On the other hand, as an upper limit of the said content rate, 0.95 mol is preferable and 0.3 mol is more preferable.

((C) Radiation sensitive acid generator)
(C) The radiation-sensitive acid generator generates an acid when the first radiation is irradiated and the second radiation is not irradiated, and the second radiation is not irradiated with the first radiation. It is a component that does not substantially generate the acid when irradiated with radiation alone, and is different from the (a) radiation-sensitive acid-sensitizer generating agent. (C) Since the radiation-sensitive acid generator has the above properties, it can generate an acid only at the pattern exposure portion of the resist material film by a radiation sensitization reaction during batch exposure.

(C) Examples of the cation (I) in the [C1] compound contained in the radiation-sensitive acid generator include the monovalent onium cation represented by X ⁺ as the cation (I) and the cation (II). And decomposed by exposure light exposure. In the exposed portion, sulfonic acid is generated from protons generated by the decomposition of the onium cation and the sulfonate anion. This cation does not generate a radiation-sensitive sensitizer.

Examples of the monovalent onium cation represented by X + include cations represented by the above formulas (X-1), (X-2), (X-3) and (X-4).

Examples of the anion (I) in the above [C1] compound include the same anions as those exemplified as the above-mentioned anion (I), for example, an iodonium salt compound and a sulfonium salt compound which are the above-mentioned onium salt compounds. .

Examples of such a (C) compound [C1] that serves as a radiation-sensitive acid generator include JP-A-2016-054772, JP-A-2014-063160, JP-A-2014-191061, and JP-A-2006-. And radiation sensitive acid generator compounds described in JP-A-215202, JP-A-2006-215271, and JP-A-2004-004557. Specific examples of the [C1] compound include the following compounds.

(C) As a radiation sensitive acid generator, you may also have compounds other than the said [C1] compound, (c) As a radiation sensitive acid generator other than a [C1] compound, other onium salt, for example A compound, a sulfonimide compound, a diazomethane compound, etc. are mentioned. Examples of other onium salt compounds include other sulfonium salt compounds.

(C) The radiation-sensitive acid generator may be in the form of (1) a group included as a polymer structural unit of a polymer component and incorporated as part of the polymer. In this case, (c) the radiation sensitive acid generator is present in a form in which a group obtained by removing one hydrogen atom from the above compound is bonded to the polymer. Specific examples of the (c) radiation sensitive acid generator in the form of a group incorporated as a part of the polymer include the following compounds.

When (c) the radiation-sensitive acid generator is a component different from (1) the polymer component, (1) the lower limit of the blending amount of the (c) radiation-sensitive acid generator with respect to 100 parts by mass of the polymer component 0.1 part by mass is preferable, and 1 part by mass is more preferable. On the other hand, as an upper limit of the said compounding quantity, 50 mass parts is preferable and 30 mass parts is more preferable.

When (c) the radiation sensitive acid generator is included as a structural unit of the polymer of (1) polymer component, (c) the content of (c) the radiation sensitive acid generator with respect to 1 mol of the polymer component As a minimum of a rate, 0.01 mol is preferred, 0.02 mol is more preferred, and 0.1 mol is still more preferred. On the other hand, the upper limit of the content ratio is preferably 0.5 mol, more preferably 0.3 mol.

The (a) radiation-sensitive acid-sensitizer generator or the (c) radiation-sensitive acid generator in the chemically amplified resist material was generated from the (b) radiation-sensitive sensitizer generator. You may further contain the component which does not generate | occur | produce an acid by the effect | action of the radiation sensitive sensitizer which absorbs the said 2nd radiation. Specific examples of such components include the following compounds.

Further, the chemically amplified resist material may further contain (g) a radiation-sensitive photodegradable base-radiation-sensitive sensitizer generating agent. (G) The radiation-sensitive photodegradable base-radiosensitive sensitizer generating agent absorbs the second radiation when irradiated with the first radiation and not with the second radiation. A radiation sensitizer is generated and loses basicity with respect to the acid generated from the component (2). On the other hand, after irradiation with the first radiation, irradiation with the second radiation is performed. The radiation sensitizer absorbs the second radiation and loses basicity to the acid generated from the component (2). In addition, (g) the radiation-sensitive photodegradable base-radiosensitive sensitizer generating agent is a radiation-sensitive sensitizer that is irradiated with only the second radiation without being irradiated with the first radiation. The basicity is maintained with respect to the acid generated from the component (2). Further, (g) the radiation-sensitive photodegradable base-radiosensitive sensitizer generator has a reduction potential higher than that of triphenylsulfonium.

[Other acid diffusion control agents]
The chemically amplified resist material may contain an acid diffusion controller other than the [C2] compound. Other acid diffusion control agents capture acids and cations and function as quenchers. The chemical amplification resist material contains another acid diffusion control agent, so that the excess acid generated in the resist material film is neutralized, and an acid latent image between the pattern exposed portion and the pattern non-exposed portion is obtained. Can increase the chemical contrast.

The acid diffusion controller is classified into a compound having radiation sensitivity and a compound having no radiation sensitivity.

The compound having no radiation sensitivity is a basic compound having basicity to the acid generated from the (a) radiation-sensitive acid-sensitizer generator or (c) the radiation-sensitive acid generator. Is preferred. Examples of the basic compound include a hydroxide compound, a carboxylate compound, an amine compound, an imine compound, an amide compound, and the like. More specifically, primary to tertiary aliphatic amines, aromatic amines, Heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide compounds, imide compounds, etc. Can be mentioned.

The basic compounds include: Troger's base; hindered amines such as diazabicycloundecene (DBU) and diazabicyclononene (DBM); tetrabutylammonium hydroxide (TBAH) and tetrabutylammonium lactate It may be an ionic quencher.

Examples of the primary aliphatic amine include ammonia, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert-amylamine, and cyclopentylamine. Hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine and the like.

Examples of the secondary aliphatic amine include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine, dicyclopentylamine, and diheptyl. Xylamine, dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepentamine, etc. It is done.

Examples of the tertiary aliphatic amine include trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine, tricyclopentylamine, Trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, tridodecylamine, tricetylamine, N, N, N ′, N′-tetramethylmethylenediamine, N, N , N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyltetraethylenepentamine and the like.

Examples of the aromatic amine and heterocyclic amine include aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline and 4-methylaniline. , Ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, N, N- Aniline derivatives such as dimethyltoluidine; diphenyl (p-tolyl) amine; methyldiphenylamine; triphenylamine; phenylenediamine; naphthylamine; diaminonaphthalene; pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dimethylpyrrole, 2, 5-dimethyl Pyrrole derivatives such as roll and N-methylpyrrole; oxazole derivatives such as oxazole and isoxazole; thiazole derivatives such as thiazole and isothiazole; imidazole derivatives such as imidazole, 4-methylimidazole and 4-methyl-2-phenylimidazole; pyrazole Derivatives; furazane derivatives; pyrroline derivatives such as pyrroline and 2-methyl-1-pyrroline; pyrrolidine derivatives such as pyrrolidine, N-methylpyrrolidine, pyrrolidinone and N-methylpyrrolidone; imidazoline derivatives; imidazolidine derivatives; pyridine, methylpyridine, ethyl Pyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl 2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 4-pyrrolidinopyridine, 2- (1-ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc. Pyridazine derivative; pyrimidine derivative; pyrazoline derivative; pyrazolidine derivative; piperidine derivative; piperazine derivative; morpholine derivative; indole derivative; isoindole derivative; 1H-indazole derivative; indoline derivative; quinoline, 3-quinolinecarbonitrile Isoquinoline derivatives; cinnoline derivatives; quinazoline derivatives; quinoxaline derivatives; phthalazine derivatives; purine derivatives; Carbazole derivatives; phenanthridine derivatives; acridine derivatives; phenazine derivatives; 1,10-phenanthroline derivatives; adenine derivatives; adenosine derivatives; guanine derivatives; guanosine derivatives;

Examples of the nitrogen-containing compound having a carboxy group include aminobenzoic acid; indolecarboxylic acid; nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, phenylalanine, threonine, Examples include amino acid derivatives such as lysine, 3-aminopyrazine-2-carboxylic acid, and methoxyalanine.

Examples of the nitrogen-containing compound having a sulfonyl group include 3-pyridinesulfonic acid and pyridinium p-toluenesulfonate.

Examples of the nitrogen-containing compound having a hydroxyl group, the nitrogen-containing compound having a hydroxyphenyl group, and the alcoholic nitrogen-containing compound include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate, Monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N-diethylethanolamine, triisopropanolamine, 2,2'-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol, 4- Amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) ethyl] pipera Piperidine ethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2-hydroxyethyl) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, 8-hydroxyurolidine, 3-cuincridinol, 3-tropanol, 1-methyl-2-pyrrolidineethanol, 1-aziridineethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) iso And nicotinamide.

Examples of the amide compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, 1-cyclohexylpyrrolidone and the like.

Examples of the imide compound include phthalimide, succinimide, maleimide and the like.

The above-mentioned compounds having radiation sensitivity are classified into compounds that are decomposed by radiation and lose acid diffusion control ability (radiolysis type compounds) and compounds that are generated by radiation and obtain acid diffusion control ability (radiation generation type compounds).

The radiation-decomposable compound is decomposed only in the pattern exposure part in the pattern exposure step, so that the action of capturing the acid and cation is reduced in the pattern exposure part, and the action of capturing the acid and cation is maintained in the pattern non-exposed part. The For this reason, the chemical contrast of the latent image of the acid between the exposed part and the non-exposed part can be improved.

As the radiolytic compound, sulfonates and carboxylates of radiolytic cation other than the [C1] compound and the [C2] compound are preferable. The sulfonic acid in the sulfonate is preferably a weak acid, more preferably a hydrocarbon group having 1 to 10 carbon atoms, and the hydrocarbon group not containing fluorine. Examples of such sulfonic acids include sulfonic acids such as alkyl sulfonic acids, benzene sulfonic acids, and 10-camphor sulfonic acids. The carboxylic acid in the carboxylate is preferably a weak acid, more preferably a carboxylic acid having 1 to 20 carbon atoms. Examples of such carboxylic acids include carboxylic acids such as formic acid, acetic acid, propionic acid, tartaric acid, succinic acid, cyclohexyl carboxylic acid, benzoic acid, and salicylic acid. The radiolytic cation in the carboxylate of the radiolytic cation is preferably an onium cation, and examples of the onium cation include an iodonium cation.

The radiation generating compound is generated only in the pattern exposure part in the pattern exposure step, so that the action of capturing the acid and cation occurs in the pattern exposure part and does not occur in the pattern non-exposure part.

The radiation generating compound may be generated in a batch exposure process without being generated in the pattern exposure process. In this case, a radiation-sensitive sensitizer can be efficiently generated in the exposed portion of the pattern exposure step, and unnecessary acids and cations can be captured in the non-exposed portion of the batch exposure step.

As the radiation-generating compound, a compound that generates a base upon exposure (a radiation-sensitive base generator) is preferable, and a nitrogen-containing organic compound that generates an amino group is more preferable.

Examples of the radiation sensitive base generator include, for example, JP-A-4-151156, JP-A-4-162040, JP-A-5-197148, JP-A-5-5995, JP-A-6-194634, JP-A-8-146608, No. 10-83079 and compounds described in European Patent No. 622682.

Examples of the radiation sensitive base generator include a compound containing a carbamate group (urethane bond), a compound containing an acyloxyimino group, an ionic compound (anion-cation complex), a compound containing a carbamoyloxyimino group, and the like. Preferred are a compound containing a carbamate group (urethane bond), a compound containing an acyloxyimino group, and an ionic compound (anion-cation complex).

Furthermore, as the radiation sensitive base generator, a compound having a ring structure in the molecule is preferable. Examples of this ring structure include benzene, naphthalene, anthracene, xanthone, thioxanthone, anthraquinone, fluorene, and the like.

Examples of the radiation sensitive base generator include 2-nitrobenzyl carbamate, 2,5-dinitrobenzyl cyclohexyl carbamate, N-cyclohexyl-4-methylphenylsulfonamide, 1,1-dimethyl-2-phenylethyl. -N-isopropyl carbamate and the like.

The acid diffusion control agent may be a compound (heat generation type compound) that is generated by a thermal reaction and obtains acid diffusion control ability. In this case, it is preferable to generate in the baking process after the batch exposure process. Thus, it is preferable that the heating temperature in the baking process mentioned later is higher than the heating temperature in another process from a viewpoint that an acid diffusion control agent acquires acid diffusion control ability in a baking process.

Among the other acid diffusion control agents having radiation sensitivity, (e) basicity against acid generated from component (2) when irradiated with the first radiation and not irradiated with the second radiation. Examples of the acid diffusion control agent that has a reduction potential lower than that of the triphenylsulfonium cation include the following compounds.

When the chemically amplified resist material contains the other acid diffusion control agent, (1) The lower limit of the content of the acid diffusion control agent with respect to 100 parts by mass of the polymer component is preferably 0.001 part by mass, 0.01 parts by weight is more preferable. On the other hand, as an upper limit of the said content, 20 mass parts is preferable and 10 mass parts is more preferable. When the said content is smaller than the said minimum, there exists a possibility that the said acid diffusion control agent cannot fully capture | acquire an acid and a cation. On the contrary, when the content exceeds the upper limit, the sensitivity may be excessively lowered.

[Radical scavenger]
The radical scavenger traps free radicals. When the chemically amplified resist material contains the radical scavenger, the generation of radiation-sensitive sensitizers via reaction by radicals in the pattern non-exposed portion is reduced, and the pattern exposed portion after the batch exposure step described later and The contrast of the acid concentration with the non-exposed part can be further improved. Examples of the radical scavenger include compounds such as phenolic compounds, quinone compounds, and amine compounds, and natural antioxidants such as rubber.

[Crosslinking agent]
The cross-linking agent is used to cause a cross-linking reaction between polymer components by an acid catalyst reaction in a baking step after collective exposure, to increase the molecular weight of the polymer component, and to insolubilize in the developer. 1) It is different from the polymer component. Since the resist material contains a cross-linking agent, the polar part becomes nonpolar at the same time as the cross-linking and becomes insoluble in the developer, so that a negative resist material can be provided.

The crosslinking agent is a compound having two or more functional groups. The functional group is preferably at least one selected from the group consisting of a (meth) acryloyl group, a hydroxymethyl group, an alkoxymethyl group, an epoxy group, and a vinyl ether group.

[Other additives]
Examples of other additives include surfactants, antioxidants, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, and dyes. Known materials can be selected for the surfactant, antioxidant, dissolution inhibitor, plasticizer, stabilizer, colorant, antihalation agent, and dye. As the surfactant, for example, an ionic or nonionic fluorine-based surfactant, a silicon-based surfactant, or the like can be used. Antioxidants include, for example, phenolic antioxidants, antioxidants composed of organic acid derivatives, sulfur-containing antioxidants, phosphorus antioxidants, amine antioxidants, and antioxidants composed of amine-aldehyde condensates. And an antioxidant comprising an amine-ketone condensate.

[solvent]
The solvent is for dissolving the composition of the resist material and facilitating the formation of the resist material film by a coating machine using a spin coating method or the like. In addition, the compound included in said (b) radiation sensitive sensitizer generator etc. shall be remove | excluded from a solvent. Examples of the solvent include ketones such as cyclohexanone and methyl-2-amylketone; 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol and the like Alcohols; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether; and propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, Ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, 3-ethoxypropionic acid Chill acetate tert- butyl, tert- butyl propionate, propylene glycol monomethyl ether acetate, and esters such as propylene glycol monobutyl tert- butyl ether acetate.

[Method of preparing chemically amplified resist material]
The chemically amplified resist material can be prepared, for example, by mixing (1) a polymer component, (2) component, and other optional components as necessary at a predetermined ratio. The chemically amplified resist material is preferably filtered after mixing with, for example, a filter having a pore diameter of about 0.2 μm. The lower limit of the total solid content concentration of the chemically amplified resist material is usually 0.1% by mass, preferably 0.5% by mass, and more preferably 1% by mass. On the other hand, the upper limit of the total solid content is usually 50% by mass, preferably 30% by mass, and more preferably 20% by mass.

<Resist pattern formation method>
The resist material is preferably used in a two-step exposure lithography process. That is, the lithography process (resist pattern forming method) according to the present embodiment includes a film forming step of forming a resist material film formed using the resist material on a substrate, and a mask formed on the resist material film. A pattern exposure step of irradiating the first radiation; a batch exposure step of irradiating the resist material film after the pattern exposure step with a second radiation; and a baking step of heating the resist material film after the batch exposure step; And a step of bringing the resist material film after the baking step into contact with a developer.

FIG. 1 is a process diagram showing a lithography process according to this embodiment. FIG. 2 is a process diagram showing an example of a resist pattern forming method using a conventional chemically amplified resist material.

As shown in FIG. 1, the lithography process according to this embodiment includes the following steps.
Step S1: Step of preparing a substrate to be processed Step S2: Step of forming a lower layer film and a resist material film (film formation step)
Step S3: A step of generating an acid in the exposed portion by pattern exposure (pattern exposure step)
Step S4: a step of multiplying acid only in the pattern exposure portion by batch exposure (collective exposure step)
Step S5: A step of causing a polarity change reaction by an acid catalyst in the pattern exposed portion by baking after exposure (baking step).
Step S6: Step of forming a resist pattern by development processing (development step)
Step S7: Step of transferring pattern by etching (etching step)

(Process S1)
The substrate to be processed (substrate to be processed) in the following steps may be composed of a semiconductor wafer such as a silicon substrate, a silicon dioxide substrate, a glass substrate, and an ITO substrate, and is insulated on the semiconductor wafer. A film layer may be formed.

(Process S2: Film formation process)
The resist material film is formed using the resist material of this embodiment. Examples of the method for forming the resist material film include a method of applying a liquid resist material by spin coating or the like, a method of attaching a film-like (solid) resist material, and the like. When applying a liquid resist material, the solvent in the resist material may be volatilized by heating (pre-baking) after application. The formation conditions of the resist material film are appropriately selected according to the properties of the resist material and the thickness of the resist material film to be obtained. The average thickness of the resist material film is preferably 1 nm to 5,000 nm, more preferably 10 nm to 1,000 nm, and even more preferably 30 nm to 200 nm.

Prior to forming the resist material film on the substrate, a lower layer film (an antireflection film, a film for improving resist adhesion, a film for improving resist shape, etc.) may be formed on the substrate. By forming the antireflection film, it is possible to suppress the occurrence of standing waves due to radiation reflected by the substrate or the like in the pattern exposure step. By forming a film for improving the resist adhesion, the adhesion between the substrate and the resist material film can be improved. By forming a film for improving the resist shape, the resist shape after development can be further improved. That is, by forming a film for improving the resist shape, it is possible to reduce the skirt shape or constriction shape of the resist. On the other hand, in order to prevent resist shape deterioration due to the generation of standing wave of batch exposure radiation, it is preferable to design the thickness of the lower layer film so that reflection of the radiation of batch exposure can be suppressed. The lower layer film is preferably a film that does not absorb the radiation for batch exposure. If the lower layer film absorbs the radiation of the batch exposure, a radiation sensitization reaction may occur in the resist material film due to energy transfer or electron transfer from the lower layer film, which may generate acid in the pattern unexposed area. . For this reason, a buffer layer that does not propagate the radiation sensitization reaction may be disposed between the resist material film and the lower layer film to prevent sensitization from the lower layer film that has absorbed the radiation.

A protective film may be further formed on the resist material film. By forming the protective film, it is possible to suppress the deactivation of the radiation-sensitive sensitizer, acid, and these reaction intermediates generated in the pattern exposure step S3, thereby improving the process stability. The protective film has at least one wavelength of non-ionizing radiation that is directly absorbed by the component (a) or (c) (radiation sensitive acid generator) in order to prevent an acid generation reaction in an unexposed portion in the batch exposure process. An absorption film that absorbs the portion may be used. By using the absorption film, it is possible to suppress the entry of out-of-band light (OOB light), which is ultraviolet radiation generated during EUV exposure, into the resist material film, and the radiation-sensitive acid generator in the pattern unexposed area or The decomposition of the radiation sensitive acid generating group can also be prevented. Further, when the absorption film is directly formed on the resist material film, the wavelength of the second radiation in the batch exposure process is used to suppress acid generation in the resist material film due to the radiation sensitization reaction in the pattern unexposed area. It is preferable that it does not induce a radiosensitization reaction from the protective film. In addition, a buffer layer is disposed between the resist material film and the protective film to absorb the radiation so that the radiation-sensitive sensitizer in the resist material film is not sensitized by energy transfer or electron transfer from the protective film. Sensitization from the absorbing film may be prevented. By forming the absorption film on the resist material film after the pattern exposure step S3 and before the collective exposure step S4, the resist material film after the pattern exposure step S3 is formed by irradiation with the second radiation in the collective exposure step S4. Direct generation of acid from the remaining radiation-sensitive acid generator or radiation-sensitive acid-generating group can be further suppressed.

(Process S3: Pattern exposure process)
In the pattern exposure step S3, a light shielding mask having a predetermined pattern is arranged on the resist material film formed in the film formation step S2. Thereafter, the resist material film is irradiated with the first radiation (pattern exposure) through the mask from an exposure apparatus (radiation irradiation module) having a projection lens, an electron optical system mirror, or a reflection mirror.

The first radiation used for pattern exposure is ionizing radiation or non-ionizing radiation having a wavelength of 250 nm or less. The upper limit of the wavelength of the non-ionizing radiation is 250 nm, and preferably 200 nm. On the other hand, the lower limit of the wavelength of the non-ionizing radiation is preferably 150 nm, and more preferably 190 nm.

Note that ionizing radiation is radiation having sufficient energy to ionize atoms or molecules. In contrast, non-ionizing radiation is radiation that does not have sufficient energy to ionize atoms or molecules. Examples of the ionizing radiation include gamma rays, X-rays, alpha rays, heavy particle rays, proton rays, beta rays, ion beams, electron beams, EUV, and the like. The ionizing radiation used for pattern exposure is preferably an electron beam, EUV or ion beam, more preferably an electron beam or EUV. Non-ionizing radiation includes non-ionizing radiation having a wavelength of 250 nm or less, such as KrF excimer laser light and ArF excimer laser light.

As a light source for pattern exposure, for example, an electron beam of 1 keV to 200 keV, EUV having a wavelength of 13.5 nm, excimer laser light of 193 nm (ArF excimer laser light), and excimer laser light of 248 nm (KrF excimer laser light) are used. There are many cases. The exposure amount in pattern exposure may be smaller than in the case of batch exposure using the chemically amplified resist of the present embodiment. By the pattern exposure, groups represented by the components (a) to (c) in the resist material film are decomposed to generate an acid and a radiation-sensitive sensitizer that absorbs the second radiation.

For exposure, a step-and-scan type exposure apparatus called a “scanner” is widely used. In this method, a pattern for each shot is formed by performing scanning exposure while synchronizing the mask and the substrate. By this exposure, a selective reaction occurs at the exposed portion in the resist.

Prior to performing the following batch exposure step S4, the radiation-sensitive acid generator in the component (a) or (c) is directly absorbed on the resist material film in the post-pattern exposure step S3. An absorption film that absorbs at least a part of the wavelength of the ionizing radiation may be formed. By forming the absorption film, the radiation sensitive acid generator or the radiation sensitive acid generating group remaining in the resist material film after the pattern exposure step S3 due to the irradiation of the second radiation in the collective exposure step S4 below. The direct acid generation of can be further suppressed.

In the case of using (b) a radiation-sensitive sensitizer generator having an alcoholic hydroxyl group in which hydrogen atoms are not substituted, the resist material film is formed until the following batch exposure step S4 is performed after the pattern exposure step S3. It is preferable to place in a reduced-pressure atmosphere or an inert atmosphere containing nitrogen or argon. By placing the resist material film in the above atmosphere, the exposure of the resist material film to oxygen during exposure and the termination of radical reaction by this oxygen can be suppressed, and the acid quenching by a small amount of basic compound can be suppressed. Since the chin can be suppressed, the process tends to be further stabilized. The upper limit of the time (storage time) until the collective exposure step S4 is performed after the pattern exposure step S3 is preferably 30 minutes, and more preferably 10 minutes. There exists a tendency which can suppress the fall of a sensitivity because storage time is 30 minutes or less. On the other hand, when (b) a radiation-sensitive sensitizer generating agent (that is, a ketal compound, an acetal compound or an orthoester compound) having an alcoholic hydroxyl group substituted with a hydrogen atom is used, after the pattern exposure step S3, the following Until the collective exposure step S4 is performed, it is preferable that the atmosphere in which the resist material film exists is in the atmosphere cleaned with an amine removal filter. When the above-mentioned (b) radiation-sensitive sensitizer generating agent is used, it may be treated in the atmosphere cleaned with an amine removing filter because it is not easily affected by oxygen as described above. By placing the resist material film in the above atmosphere, acid quenching by a small amount of a basic compound can be suppressed, so that the process tends to be further stabilized. The upper limit of the time (storage time) until the collective exposure step S4 is performed after the pattern exposure step S3 is preferably 30 minutes, and more preferably 10 minutes. There exists a tendency which can suppress the fall of a sensitivity because storage time is 30 minutes or less.

In the resist pattern forming method of this embodiment, after the pattern exposure step S3 and before the following batch exposure step S4, the substrate is transferred from the exposure apparatus that performs the pattern exposure step S3 to the exposure device that performs the batch exposure step S4. You may further provide the process. Further, the batch exposure may be performed in a coating and developing apparatus connected inline or in a module corresponding to an interface with the exposure machine. When the component (2) includes a ketal compound, an acetal compound or an orthoester compound, the resist pattern forming method of this embodiment is performed after the pattern exposure step S3 and before the following batch exposure step S4, followed by a baking step S3a (post Pattern exposure bake (also referred to as PPEB or PEB)) (see FIG. 3). The heating temperature in the baking step is preferably 30 ° C. or higher and 150 ° C. or lower, more preferably 50 ° C. or higher and 120 ° C. or lower, and further preferably 60 ° C. or higher and 100 ° C. or lower. The heating time is preferably 5 seconds to 3 minutes, more preferably 10 seconds to 60 seconds. Moreover, it is preferable to perform the said baking in the environment which controlled humidity. This is because when the hydrolysis reaction is used as the deprotection reaction for generating the radiation-sensitive sensitizer, the humidity affects the reaction rate. When the resist pattern forming method includes the baking step S3a, it is possible to accelerate the generation of a radiation-sensitive sensitizer due to a hydrolysis reaction from an acetal compound, an ortho ester compound, a ketal compound or the like to a carbonyl compound.

(Process S4: Batch exposure process)
In the batch exposure step S4, a high-sensitivity module (exposure device or light source) having a projection lens (or light source) on the entire resist material film after the pattern exposure step S3 (the entire surface including the pattern exposed portion and the pattern unexposed portion). The second radiation is irradiated (collective exposure) from a radiation irradiation module. As this collective exposure, the entire wafer surface may be exposed at one time, a combination of local exposures, or overlapping exposure. As a light source for batch exposure, a general light source can be used. In addition to ultraviolet rays from mercury lamps and xenon lamps controlled to a desired wavelength by passing through a pan-pass filter or a cut-off filter, LEDs are used. Narrow-band ultraviolet light from a light source, laser diode, laser light source, or the like may be used. In the collective exposure, only the radiation-sensitive sensitizer generated at the pattern exposure portion in the resist material film absorbs radiation. For this reason, in the batch exposure, radiation is selectively absorbed in the pattern exposure portion. Therefore, during the batch exposure, the acid can be continuously generated only in the pattern exposure part, and the sensitivity can be greatly improved. On the other hand, since no acid is generated in the pattern unexposed area, the sensitivity can be improved while maintaining the chemical contrast in the resist material film.

The second radiation used for the collective exposure is a non-ionizing radiation having a wavelength longer than the wavelength of the non-ionizing radiation in the first radiation and having a wavelength exceeding 250 nm, and a near ultraviolet ray (wavelength of 250 to 450 nm). ) Is preferred.

In the collective exposure step S4, in order to suppress the acid generation reaction in the pattern unexposed area, (1) from the wavelength of radiation that can be absorbed by the polymer component, the radiation sensitive acid generator, and the radiation sensitive sensitizer generator. It is necessary to expose with radiation having a long wavelength. Considering these, the lower limit of the wavelength of non-ionizing radiation in the batch exposure is preferably 280 nm, and more preferably 320 nm. When generating a radiation-sensitive sensitizer capable of absorbing longer wavelength radiation, the wavelength of the non-ionizing radiation may be 350 nm or more. However, if the wavelength of the non-ionizing radiation is too long, the efficiency of the radiation sensitization reaction is reduced, so the wavelength of radiation that can be absorbed by the polymer component, the radiation sensitive acid generator, and the radiation sensitive sensitizer generator. It is preferable to use non-ionizing radiation having a wavelength as short as possible that can be absorbed by the radiation-sensitive sensitizer. From such a viewpoint, the upper limit of the wavelength of the non-ionizing radiation is preferably 450 nm, and more preferably 400 nm.

The pattern exposure step S3 and / or the batch exposure step S4 may be performed by immersion lithography (immersion exposure), or may be performed by dry lithography (dry exposure). Immersion lithography refers to exposure performed with a liquid interposed between a resist material film and a projection lens. On the other hand, dry lithography refers to exposure performed in a state where a gas is interposed between a resist material film and a projection lens, under reduced pressure, or in a vacuum.

In the immersion lithography in the pattern exposure step S3 and / or the batch exposure step S4, a liquid having a refractive index of 1.0 or more is applied between the resist material film or the protective film formed in the film formation step S2 and the projection lens. You may carry out in the state interposed. The protective film is preferably for preventing reflection or improving reaction stability. The protective film preferably prevents liquid penetration, enhances water repellency on the film surface, and prevents defects due to liquid in immersion exposure.

In the immersion lithography in the collective exposure step S4, the liquid absorbs at least part of the wavelength of the second radiation directly absorbed by the component (a) or (c) (the radiation-sensitive acid generator). By using the liquid in the immersion lithography, the radiation-sensitive acid generator remaining in the resist material film after the pattern exposure step S4 by irradiation with the second radiation in the batch exposure step S4 or The direct acid generation from the radiation sensitive acid generating group can be further suppressed.

When the pattern exposure step S3 and / or the batch exposure step S4 is performed by dry lithography, the pattern exposure step S3 and / or the batch exposure step S4 can be performed in the air, in a reduced pressure atmosphere, or in an inert atmosphere, but include a reduced pressure atmosphere or nitrogen or argon. It is preferable to carry out in an inert atmosphere. Furthermore, the upper limit of the concentration of the basic compound in the atmosphere during the implementation is preferably 20 ppb, more preferably 5 ppb, and even more preferably 1 ppb.

(Process S5: Baking process)
In the baking step S5, the resist material film after the batch exposure step S4 is heated (hereinafter also referred to as “post-flood exposure baking (PFEB)” or “post-exposure baking (PEB)”). When the resist pattern forming method of the present embodiment includes the baking step S3a after the pattern exposure step S3 and before the batch exposure step S4, the baking step S3a is referred to as a 1st PEB step, and the baking step S5 is referred to as a 2nd PEB step. Yes (see FIG. 3). The heating condition can be, for example, 50 ° C. or higher and 200 ° C. or lower and 10 seconds or longer and 300 seconds or shorter in an atmosphere of an inert gas such as nitrogen or argon. By setting the heating condition within the above range, acid diffusion can be controlled, and the processing speed of the semiconductor wafer tends to be ensured. In the baking step S5, the acid generated in the pattern exposure step S3 and the batch exposure step S4 causes (1) a polarity change reaction such as a deprotection reaction of the polymer component and a crosslinking reaction. Further, although the resist side wall may be wavy due to the influence of the standing wave of radiation in the resist material film, the waviness can be reduced by diffusion of reactants in the baking step S5.

(Step S6: Development step)
In the developing step S6, the resist material film after the baking step S5 is brought into contact with a developer. Development is performed by utilizing the fact that the solubility in the developer is selectively changed in the pattern exposure portion by the reaction in the resist material film in the baking step S5, so that a resist pattern is formed. The developer can be divided into a positive developer and a negative developer.

An alkaline developer is preferable as the positive developer. The alkaline developer selectively dissolves the highly polar part of the resist material film after exposure. Examples of the alkaline developer include potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines (ethanolamine, etc.), and tetraalkylammonium hydroxide (TAAH). . TAAH is preferred as the alkaline developer. As TAAH, for example, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide, water Trimethyl (2-hydroxyethyl) ammonium oxide (ie, choline), triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldi (2-hydroxyethyl) ammonium hydroxide, diethyldi (2-hydroxyethyl) ammonium hydroxide, hydroxylated Methyltri (2-hydroxyethyl) ammonium, ethyltri (2-hydroxyethyl) ammonium hydroxide, tetra (2-hydroxyethyl) ammonium hydroxide, etc. It is below.

A 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) is widely used as a positive developer.

In alkali development, a pattern is formed by utilizing a phenomenon in which carboxylic acid or hydroxyl group generated in a resist material film after exposure is ionized and dissolved in an alkali developer. After the development, in order to remove the developer remaining on the substrate, a water washing process called rinsing is performed.

The negative developer is preferably an organic developer. The organic developer selectively dissolves the low polarity portion of the resist material film after exposure. The organic developer is used to improve the resolution performance and the process window by removing patterns such as holes and trenches. In this case, the dissolution contrast between the pattern exposed portion and the pattern unexposed portion is obtained by the difference in affinity between the solvent in the resist material film and the organic developer. The portion with high polarity has low solubility in an organic developer, and remains as a resist pattern. Examples of organic developers include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl Acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonic acid, ethyl crotonic acid , Methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate , Examples include methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, and the like. .

The resist pattern after the development step S6 (including rinse treatment) may be heated (sometimes referred to as post-baking). The post-baking can vaporize and remove the rinsing liquid remaining after the rinsing process, and can cure the resist pattern.

(Process S7)
In step S7, a pattern is formed by etching or ion implantation of the underlying substrate using the resist pattern after the developing step S6 as a mask. The etching may be dry etching under an atmosphere such as plasma excitation, or may be wet etching immersed in a chemical solution. After the pattern is formed on the substrate by etching, the resist pattern is removed.

The resist pattern forming method of the present embodiment includes the pattern exposure step S3 and the batch exposure step S4, so that the acid generated after the exposure can be greatly increased only in the pattern exposed portion.

FIG. 4 is a graph showing the absorbance of the pattern exposed portion and the unexposed portion of the resist material film at the time of batch exposure. The portion of the resist material film that is not subjected to pattern exposure (pattern unexposed portion) absorbs ultraviolet rays having a relatively short wavelength, but does not absorb ultraviolet rays having a long wavelength. On the other hand, as described above, an acid and a radiation-sensitive sensitizer are generated in the pattern-exposed portion (pattern exposed portion) of the resist material film. The generated radiation-sensitive sensitizer absorbs non-ionizing radiation having a wavelength exceeding 200 nm, and absorbs ultraviolet rays having a relatively long wavelength. In the batch exposure, the entire surface of the resist material film is irradiated without using a mask as in the pattern exposure, but the second radiation is not absorbed in the batch exposure step S4 in the pattern unexposed portion. Accordingly, in the batch exposure step S4, the above-described third to fifth and seventh acid generation mechanisms mainly occur in the pattern exposure unit. For this reason, an acid can be continuously generated only in the pattern exposure part during the batch exposure, and the sensitivity can be improved while maintaining the lithography characteristics.

FIG. 5 (a) is a conceptual diagram showing, as a graph, an acid concentration distribution by a resist pattern forming method using a conventional chemically amplified resist material. When only pattern exposure is performed by EUV or the like as shown in FIG. 2, sufficient acid cannot be generated and sensitivity is lowered. When the exposure amount is increased in order to improve the sensitivity, the latent image of the resist pattern is deteriorated (lithography characteristics are lowered), so that it is difficult to achieve both sensitivity and lithography characteristics. FIG. 5B is a conceptual diagram showing, as a graph, the radiation-sensitive sensitizer concentration distribution and the acid concentration distribution obtained by the resist pattern forming method using the chemically amplified resist material according to the present embodiment. In pattern exposure, although a resist pattern latent image is excellent, sufficient acid is not generated. However, after batch exposure, the amount of acid can be increased only in the pattern exposure area by the radiation-sensitive sensitizer generated by pattern exposure, and sensitivity can be reduced with low exposure while maintaining an excellent latent image of the resist pattern. Can be improved. Since the acid generation mechanism by the radiation-sensitive sensitizer at the time of batch exposure occurs at room temperature, there is little bleeding of the latent image at the time of acid generation, and it is possible to greatly increase the sensitivity while maintaining the resolution.

<Semiconductor devices>
The semiconductor device according to the present embodiment is manufactured using the pattern formed by the above method. FIG. 6 is a cross-sectional view showing an example of the manufacturing process of the semiconductor device of this embodiment.

FIG. 6A is a cross-sectional view showing a resist pattern forming step. The semiconductor wafer 1, the film to be etched 3 formed on the semiconductor wafer 1, and the film to be etched 3 by the resist pattern forming method are shown. It is sectional drawing with the formed resist pattern 2 (equivalent after completion | finish of image development process S6). Examples of the film to be etched include an active layer, a lower insulating film, a gate electrode film, and an upper insulating film. Between the etching target film 3 and the resist pattern 2, an antireflection film, a lower layer film for improving resist adhesion, and a lower layer film for improving the resist shape may be provided. A multilayer mask structure may be adopted. FIG. 6B is a cross-sectional view showing the etching process, and is a cross-sectional view of the semiconductor wafer 1, the resist pattern 2, and the etching target film 3 etched using the resist pattern 2 as a mask. The etched film 3 is etched along the shape of the opening of the resist pattern 2. FIG. 6C is a cross-sectional view of the pattern substrate 10 including the semiconductor wafer 1 and the pattern of the etched film 3 that has been etched after the resist pattern 2 is removed.

A semiconductor device can be formed using a substrate having the pattern of the film 3 to be etched. As a method for forming this semiconductor device, for example, a method of embedding wiring between the patterns of the film to be etched 3 from which the resist pattern 2 has been removed and further laminating device elements on the substrate can be cited.

<Lithography mask>
The lithography mask according to this embodiment is manufactured by processing a substrate using the resist pattern formed by the above method. Examples of the method for producing the lithography mask include a method of etching a glass substrate surface or a hard mask formed on the glass substrate surface using a resist pattern. Here, the lithography mask includes a transmissive mask using ultraviolet rays or an electron beam, a reflective mask using EUV light, and the like. When the lithography mask is a transmissive mask, it can be manufactured by masking the light shielding portion or the phase shift portion with a resist pattern and processing by etching. Further, when the lithography mask is a reflective mask, it can be manufactured by processing the light absorber by etching using the resist pattern as a mask.

<Template for nanoimprint>
The nanoimprint template according to the present embodiment can also be manufactured using the resist pattern formed by the above method. Examples of the manufacturing method include a method of forming a resist pattern on a glass substrate surface or a hard mask surface formed on the glass substrate surface, and processing by etching.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. The measuring method of the physical property value in a present Example is shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Mw and Mn of the polymer were measured by gel permeation chromatography (GPC). The measurement uses GPC columns (2 G2000HXL, 1 G3000HXL, and 1 G4000HXL, Tosoh Corporation), flow rate 1.0 mL / min, elution solvent tetrahydrofuran, sample concentration 1.0 mass%, sample injection amount 100 μL, Under analysis conditions with a column temperature of 40 ° C., a differential refractometer was used as a detector, and monodisperse polystyrene was used as a standard substance.

[ ¹³ C-NMR analysis]
The ¹³ C-NMR analysis for determining the content of the structural unit of the polymer uses a nuclear magnetic resonance apparatus (“JNM-ECX400” manufactured by JEOL Ltd.), uses CDCl ₃ as a measurement solvent, and uses tetramethylsilane ( TMS) was performed as an internal standard.

<(1) Synthesis of polymer component>
(1) The monomers used for the synthesis of the polymer component are shown below.

The compounds (M-1), (M-4) and (M-6) are structural units (I), and the compounds (M-2) and (M-7) are structural units (IV) ( M-3) and (M-5) give the structural unit (III), and the compound (M-8) gives the structural unit (II).

[Synthesis Example 1] (Synthesis of polymer (A-1))
After dissolving 45 g (50 mol%) of the above compound (M-1), 55 g (50 mol%) of the above compound (M-2) and 3 g of azobisisobutyronitrile (AIBN) in 300 g of methyl ethyl ketone, the mixture was dissolved in a nitrogen atmosphere. The polymerization was carried out for 6 hours while maintaining the reaction temperature at 78 ° C. After the polymerization, the reaction solution was dropped into 2,000 g of methanol to solidify the polymer. Next, this polymer was washed twice with 300 g of methanol, and the resulting white powder was filtered and dried overnight at 50 ° C. under reduced pressure to obtain [A] polymer (A-1) as a polymer. Obtained. The polymer (A-1) had Mw of 7,000 and Mw / Mn of 2.10. As a result of ¹³ C-NMR analysis, the content of each structural unit derived from the compound (M-1) and the compound (M-2) was 52 mol% and 48 mol%, respectively.

[Synthesis Example 2] (Synthesis of Polymer (A-2))
After 45 g (44 mol%) of the above compound (M-1), 55 g (56 mol%) of the above compound (M-3), 3 g of AIBN and 1 g of t-dodecyl mercaptan were dissolved in 150 g of propylene glycol monomethyl ether, The polymerization was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. After the polymerization, the reaction solution was dropped into 1,000 g of n-hexane to coagulate and purify the polymer. Next, 150 g of propylene glycol monomethyl ether was added to the polymer again, and then 150 g of methanol, 37 g of triethylamine and 7 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. The structural unit derived from -3) was deacetylated. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained polymer was dissolved in 150 g of acetone, then dropped into 2,000 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure. And dried overnight to obtain a polymer (A-2) as a polymer [A]. The polymer (A-2) had Mw of 6,000 and Mw / Mn of 1.90. Further, as a result of ¹³ C-NMR analysis, the content ratio of the p-hydroxystyrene structural unit obtained by deacetylation of the structural unit derived from (M-3) and the structural unit derived from the compound (M-1) Were 50 mol% and 50 mol%, respectively.

[Synthesis Examples 3 to 4] (Synthesis of Polymers (A-3) to (A-4))
Polymers (A-3) to (A-4) as polymer components were synthesized in the same manner as in Synthesis Example 2 except that the types and amounts of monomers shown in Table 1 were used. In Table 1, it shows collectively about the content rate of Mw of each obtained polymer, Mw / Mn, and each structural unit.

[Synthesis Example 5] (Synthesis of Polymer (A-5))
Compound (M-1) 6.99 g (40 mol%), compound (M-3) 6.22 g (40 mol%) and compound (M-8) 6.79 g (20 mol%) were added to propylene glycol monomethyl ether 40 g. A monomer solution was prepared by dissolving 0.79 g of AIBN (5 mol% based on the total number of moles of the compound) as a radical polymerization initiator. After putting 20 g of propylene glycol monomethyl ether into a 100 mL three-necked flask and purging with nitrogen for 30 minutes, the reaction kettle was heated to 80 ° C. with stirring. Thereto, the monomer solution prepared above was dropped over 3 hours, and further aged for 3 hours. After completion of the polymerization, the polymerization reaction liquid was cooled with water and cooled to 30 ° C. or lower. This polymerization reaction liquid was put into 400 g of hexane, and the precipitated solid content was separated by filtration. The solid content after filtration was washed twice with 80 g of hexane, further filtered, and dried at 50 ° C. for 17 hours. This solid content was put into a 100 mL eggplant flask containing 20 g of propylene glycol monomethyl ether and dissolved. Further, 3.49 g of triethylamine and 0.56 g of pure water were added, heated to 80 ° C., and reacted for 6 hours for hydrolysis. After completion of hydrolysis, the reaction solution was cooled with water and cooled to 30 ° C. or lower. This reaction solution was put into 400 g of hexane, and the precipitated solid content was separated by filtration. The filtered solid was washed twice with 80 g of hexane, further filtered and dried at 50 ° C. for 17 hours to obtain 12.2 g (yield 61%) of the polymer (A-5). Mw of the polymer (A-5) was 7,500, and Mw / Mn was 1.52. As a result of ¹³ C-NMR analysis, a structural unit derived from (M-1), a p-hydroxystyrene structural unit obtained by deacetylation of a structural unit derived from (M-3), and (M-8) The content ratio of each structural unit derived from was 40 mol%, 40 mol%, and 20 mol%, respectively.

* The structural unit content of M-3 in the table indicates the content as a p-hydroxystyrene structural unit obtained by deacetylating the structural unit derived from M-3.

[Synthesis Example 6] (Synthesis of Compound (A-6))
Glutaraldehyde (50% by mass aqueous solution) 10 g, 3-methoxyphenol 24.8 g and trifluoroacetic acid 37.5 g were dissolved in chloroform 50 mL and refluxed for 48 hours. This solution was added to methanol, and the deposited precipitate was vacuum-dried to obtain 11.3 g of a monomolecular compound (M-9) represented by the following formula protected by a methoxy group. Next, 8.0 g of this compound (M-9), 8.2 g of potassium carbonate, and 0.064 g of tetrabutylammonium bromide were dissolved in 95 mL of N-methylpyrrolidone (NMP) and stirred at 60 ° C. for 3 hours. To this reaction solution, a mixed solution of 4.3 g of 2-bromoacetyloxy-2-methyladamantane and 5 mL of NMP was added and further stirred at 60 ° C. for 48 hours. The reaction solution was poured into chloroform, washed with a 0.1 M aqueous oxalic acid solution, dried over magnesium sulfate, filtered through celite, and the filtrate was concentrated under reduced pressure. The concentrated solution is added to methanol to precipitate a solid, which is dried under reduced pressure, whereby a compound in which 18% of the hydroxyl group of compound (M-9) is protected with a 2-acetyloxy-2-methyladamantane group ( 5.9 g of A-6) was obtained. This compound (A-6) corresponds to (1) a polymer component.

<(2) Component that generates radiation-sensitive sensitizer and acid by exposure>
[(B) Radiation-sensitive sensitizer generating agent]
(B) The following compounds were used as the radiation-sensitive sensitizer generating agent.
B-1: Compound represented by the following formula (B-1) B-2: Compound represented by the following formula (B-2)

[Absorbance measurement of component (b)]
Table 2 shows the component (b) and the sensitizer derived from the component (b). Moreover, the sensitizer derived from these (b) component and (b) component was prepared so that it might become a 0.0001 mass% cyclohexane solution, respectively. The absorbance of this prepared solution was measured using a spectrophotometer (“V-670” manufactured by JASCO Corporation) using cyclohexane as a reference solvent.

The above-mentioned absorbance was obtained by subtracting the absorbance of the reference solvent from the absorbance of the measurement solution at each wavelength of 360 nm to 450 nm. When the measured value of the absorbance in the entire wavelength region of the wavelength of 360 nm or more and 450 nm or less is less than 0.01, it is evaluated as “transparent”, and the wavelength at which the absorbance is 0.01 or more in the entire wavelength region is small Was evaluated as “absorbed”. The evaluation results are shown in Table 3 below. In addition, it confirmed that the transmittance | permeability of the cyclohexane which is a solvent used for the measurement of absorption spectrometry was 95% or more in all the wavelength ranges of wavelength 250 nm or more and 600 nm or less.

[Measurement of oxidation potential of sensitizer]
The oxidation potential of the sensitizer was measured by cyclic voltammetry in an Ar atmosphere using platinum as the working electrode, platinum wire as the counter electrode, and a saturated calomel electrode (SCE) as the reference electrode. In addition, ferrocene purified by sublimation was used as an external standard, and [n-Bu ₄ N] [ClO ₄ ] was added to a 1 mM sensitizer dissolved in acetonitrile to a concentration of 0.1 M as a supporting electrolyte. The oxidation potential was measured.
{Fe (C ₅ H ₅ ) ₂ / [Fe (C ₅ H ₅ ) ₂ ] ⁺ : E ^2/1 = + 0.38 V vs SCE, acetonitrile}
The standard hydrogen electrode (SHE) equivalent oxidation potential and oxidation energy calculated from this were determined.
The energy (E *) required to excite the sensitizer was also calculated.
These results are shown in Table 3.

[(C) Radiation sensitive acid generator]
(C) The following [C1] compound (first compound) and [C2] compound (second compound) were used as the radiation-sensitive acid generator.
(Acid generating compound)
In this example, among the [C1] compound (first compound) and the [C2] compound (second compound), the [C1] compound shown in Table 4 below is a compound having a smaller pKa of the generated acid. Was used as the acid generating compound.

[Measurement of reduction potential]
The oxidation potential of the sensitizer was measured by cyclic voltammetry in an Ar atmosphere using platinum as the working electrode, platinum wire as the counter electrode, and a saturated calomel electrode (SCE) as the reference electrode. In addition, using ferrocene purified by sublimation as an external standard, [n-Bu ₄ N] [ClO ₄ ] as a supporting electrolyte was added to 0.1 mM to 1 mM [C1] compound dissolved in acetonitrile. The reduction potential was measured.
{Fe (C ₅ H ₅ ) ₂ / [Fe (C ₅ H ₅ ) ₂ ] ⁺ : E ^2/1 = + 0.38 V vs SCE, acetonitrile}
In addition, a standard hydrogen electrode (SHE) equivalent oxidation potential and oxidation energy calculated from this were determined. The results are shown in Table 4. The acid generating compound was irreversible because it was decomposed by reduction, and only a reduction peak was observed.

(PKa of acid generated from acid generating compound ([C1] compound))
[C1] For the acid generators of compounds (C-1-1) to (C-1-7), the pKa (logarithm of the reciprocal of the acid dissociation constant) of the acid generated from these compounds is shown in Table 4. Show.

(Energy generating compound ([C1] compound) energy released when a cation is reduced to a radical)
Moreover, about the said compound, it shows in Table 4 about the calculation result of the energy discharge | released when the cation in these compounds is reduce | restored to a radical. Here, the energy was calculated from the energy difference between the cation and the radical after the structure optimization of each cation and the radical was performed, the energy level of each substance was determined by the B3LYP / LANL2DZ method.

(Acid diffusion control agent)
In this example, among the [C1] compound (first compound) and the [C2] compound (second compound), the following [C2] compound, which is the compound with the larger pKa of the generated acid, was controlled for acid diffusion. Used as an agent. The structure of the [C2] compound is shown in Table 5.

[Measurement of reduction potential]
The oxidation potential of the sensitizer was measured by cyclic voltammetry in an Ar atmosphere using platinum as the working electrode, platinum wire as the counter electrode, and a saturated calomel electrode (SCE) as the reference electrode. In addition, using ferrocene purified by sublimation as an external standard, [n-Bu ₄ N] [ClO ₄ ] as a supporting electrolyte was added to 1 mM [C2] compound dissolved in acetonitrile so as to be 0.1M. The reduction potential was measured.
{Fe (C ₅ H ₅ ) ₂ / [Fe (C ₅ H ₅ ) ₂ ] ⁺ : E ^2/1 = + 0.38 V vs SCE, acetonitrile}
Further, the reduction potential and reduction energy in terms of standard hydrogen electrode (SHE) calculated from this were determined. The results are shown in Table 5. In addition, since the acid diffusion controller is decomposed by reduction, the reduction reaction is irreversible, and only the reduction peak was observed.

(PKa of acid generated from acid diffusion controller ([C2] compound))
Regarding the acid diffusion controller of the above compounds (C-2-1) to (C-2-7), the pKa (logarithm of the reciprocal of the acid dissociation constant of the acid) of the acid (anion part) generated from these compounds Table 5 shows.

(Energy released when cations in acid diffusion controller ([C2] compound) are reduced to radicals)
[C2] Table 5 shows the calculation results of the energy released when cations in these compounds are reduced to radicals for the acid diffusion control agents of compounds (C-2-1) to (C-2-7). . The energy was calculated using the same method as that for the acid generating compound ([C1] compound) described above.

The reduction potential of compounds in which the anion moiety in these compounds was replaced with nonafluorobutanesulfonic acid anions was measured by the following measuring method.

[Measurement of reduction potential]
Measurement was carried out in the same manner as in the reduction potential measurement method described in the experimental example of JP-A-2004-004557, except that platinum was used as the working electrode and platinum wire was used as the counter electrode. The results are shown in Table 6.

(solvent)
G-1: Propylene glycol monomethyl ether acetate G-2: Cyclohexanone G-3: Ethyl lactate

[Example 1]
[A] 100 parts by mass of polymer (A-1), (b) 5 parts by mass of radiation-sensitive sensitizer generator (B-1), (c) [C1] compound (C -1-1) Mixing 15 parts by weight, 5.0 parts by weight of [C2] compound (C-2-1), 4,300 parts by weight of solvent (G-1) and 1,900 parts by weight of (G-2) did. Next, the obtained mixed solution was filtered through a membrane filter having a pore diameter of 0.20 μm to prepare a chemically amplified resist material (R-1). Further, as a reference material paired with (R-1), [A] polymer (A-1) 100 parts by mass, (b) no radiation-sensitive sensitizer generating agent, (c) radiation-sensitive acid generation [C1] Compound (C-1-1) 15 parts by mass, [C2] Compound (C-2-1) 5.0 parts by mass, solvent (G-1) 4,300 parts by mass and (G-2) ) 1,900 parts by mass were mixed. Next, the obtained mixed solution was filtered through a membrane filter having a pore diameter of 0.20 μm to prepare a chemically amplified resist material (R-1 ′).

[Examples 2 to 19 and Comparative Examples 1 to 6]
The chemical amplification resist materials (R-2) to (R-25) and the reference resist material (R-2 ′) were prepared in the same manner as in Example 1 except that the components of the types and blending amounts shown in Table 6 were used. ) To (R-25 ′) were prepared. “-” In the table indicates that the corresponding component was not added.

[Calculation of free energy (ΔG) of photosensitized energy transfer]
In each Example and Comparative Example, the free energies ΔG ^(PAG) and ΔG ^(Qu) of photosensitized energy transfer obtained from the following formulas (I) and (II) are shown together in Table 6.
ΔG ^(PAG) = (E ^{Oxi (PS)} −E ^{Red (PAG)} ) −E ^* (I)
ΔG ^(Qu) = (E ^{Oxi (PS)} −E ^{Red (Qu)} ) −E ^* (II)
In the above formulas (I) and (II), E ^{Oxi (PS)} represents the oxidation potential of the sensitizer derived from the component (b), E ^{Red (PAG)} represents the reduction potential of the [C1] compound, and E ^{Red ( Qu)} represents the reduction potential of the [C2] compound, and E * represents the energy required to excite the sensitizer derived from component (b). These energy values are shown in Tables 3 to 5. In Example 13, acid generation is performed by the acid generator unit present in the resin. In the calculation of ΔG ^{(PAG) in} Example 13, the value of triphenylsulfonium cation (C-1-3) Was substituted.

<Formation of resist pattern>
In the “Clean Track ACT-8” of Tokyo Electron Co., Ltd., after spin-coating the chemically amplified resist material prepared above on a silicon wafer, PB is performed at 110 ° C. for 60 seconds, and the resist material has an average thickness of 50 nm. A film was formed. Next, the resist material film is irradiated with an electron beam using a simple electron beam lithography apparatus (“HL800D” manufactured by Hitachi, Ltd., output 50 KeV, current density 5.0 A / cm ² ). Patterning was performed. For this patterning, a mask was used, and a line-and-space pattern (1L1S) composed of a line portion having a line width of 150 nm and a space portion having a spacing of 150 nm formed by adjacent line portions was used. After the electron beam irradiation, the following operations (1) to (3) were evaluated.

(Operation (1): No batch exposure, operation for reference materials (R-1 ′) to (R-25 ′))
After the electron beam irradiation, PEB was performed in the clean track ACT-8 at 110 ° C. for 60 seconds, and then 2.38 mass% tetramethylammonium hydroxide (TMAH) in the clean track ACT-8. Development was performed by the paddle method at 23 ° C. for 1 minute using an aqueous solution. After development, a positive resist pattern was formed by washing with pure water and drying.

(Operation (2): Operation for evaluation materials (R-1) to (R-25) with batch exposure)
After the electron beam irradiation, the entire surface of the resist material film was collectively exposed using a UV-LED light (Tokyo Electron, wavelength 365 nm). The collective exposure amount is described as the sensitivity evaluation result in Table 7 below. Next, PEB was performed in the clean track ACT-8 at 110 ° C. for 60 seconds. Thereafter, development, washing and drying were carried out in the same manner as in the above operation (1) to form a positive resist pattern.

<Evaluation>
The positive resist pattern thus formed was evaluated for sensitivity and nanoedge roughness according to the following procedure.

[sensitivity]
Optimum exposure amount (Eop) for forming a line-and-space pattern (1L1S) having a line width of 150 nm and a space portion having a space of 150 nm formed by adjacent line portions in a one-to-one line width. Was measured. The optimal exposure of the reference material is measured first, and then the optimal exposure of the evaluation material (the amount of acid diffusion control agent is increased compared to the reference material, and the sensitivity is low compared to the reference material without batch exposure) The collective exposure amount that was equivalent to the reference material was measured. The material whose collective exposure at this time is 1.0 J / cm ² or less is “AA (very good)”, and the material which exceeds 1.0 J / cm ² and is 2.0 J / cm ² or less is “A (good) )"did. In addition, from the viewpoint of apparatus throughput, a material having a collective exposure exceeding 2.0 J / cm ² is not preferable in terms of process, and therefore a material exceeding 2.0 J / cm ² is determined to be “B (defect)”. . Table 7 shows the evaluation results of sensitivity.

[Nano edge roughness]
The line pattern of the line and space pattern (1L1S) was observed using a high-resolution FEB length measuring device (“S-9220”, Hitachi, Ltd.). The shape is observed at 20 arbitrary points of the line pattern, and as shown in FIGS. 7 and 8 for each point, along the lateral side surface 12a of the line part 12 in the pattern formed on the base material (silicon wafer) 11. The difference “ΔCD” between the line width at the place where the generated unevenness was most remarkable and the design line width of 150 nm was measured. The average value of ΔCD of 20 points was used as an index of nano edge roughness. In addition, the unevenness | corrugation shown in FIG.7 and FIG.8 is exaggerated rather than actually. When the evaluation material is subjected to batch exposure to the same electron beam exposure sensitivity as the reference material, the nano edge roughness of the evaluation material (with batch exposure) is reduced by 10% or more compared to the nano edge roughness of the reference material Was judged as “AA (particularly good)”, “A (good)” when it decreased by 5% or more and less than 10%, and “B (bad)” when the decrease was less than 5% or increased. . Table 7 shows the evaluation results of the nano edge roughness.

As shown in Table 7, in Examples 1 to 19 containing the [C1] compound which is a radiation-sensitive acid generating compound and the [C2] compound which is a radiation-sensitive photodegradable base, 250 nm or less It was confirmed that high sensitivity and excellent lithography performance can be obtained when non-ionizing radiation having a wavelength of 1 is used as pattern exposure light. In particular, Example 1, Example 6, Example 9, Example 12 and Example 15 in which the onium cation of the first compound and the onium cation of the second compound have the same structure are excellent in both sensitivity and lithography performance. It was. On the other hand, in the case of the comparative example containing a [C2] compound in which the reduction potential of the compound when the anion portion is replaced with a nonafluorobutanesulfonate anion is the same as or lower than the reduction potential of triphenylsulfonium nonafluorobutanesulfonate, the lithography performance is It was confirmed that it was suppressed.

As described above, according to the chemically amplified resist material and the resist pattern forming method, ionizing radiation such as EUV light, electron beam, ion beam, or wavelength of 250 nm or less such as KrF excimer laser and ArF excimer laser is used. When using the non-ionizing radiation as pattern exposure light, it is possible to obtain high sensitivity and excellent lithography performance. Further, the chemically amplified resist material can be suitably used for the resist pattern forming method.

DESCRIPTION OF SYMBOLS 1

Semiconductor wafer

2, 12 Resist pattern 3 Etching film 10 Pattern board | substrate 11 Base material 12a Side surface of a resist pattern

Claims

(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2), and
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) is Radiation sensitivity that retains basicity with respect to the acid generated by the component (2) when the basic acid with respect to the generated acid is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base is a compound represented by the following formula (x), and the monovalent anion represented by A- in the following formula (x) was replaced with a nonafluorobutanesulfonic acid anion. The monovalent onium cation represented by M + in the following formula (z) when the compound represented by the following formula (z) is compared with triphenylsulfonium nonafluorobutanesulfonate represented by the following formula (y). The reduction potential of is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A − is a monovalent anion. M + is a monovalent onium cation. In formula (z), M + has the same meaning as in formula (x).)
(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2),
Including at least one of the component (2) and the component (3) as a structural unit of the polymer of the polymer component (1),
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) Radiation sensitivity that retains basicity with respect to the acid generated from the component (2) when the basic acid with respect to the acid generated is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base satisfies the following conditions (i) and (ii).
(I) In the case of a compound represented by the following formula (x), it is represented by the following formula (z) in which the monovalent anion represented by A − in the following formula (x) is replaced with a nonafluorobutanesulfonate anion. The reduction potential of the monovalent onium cation represented by M + in the following formula (z) when comparing the above compound with triphenylsulfonium nonafluorobutane sulfonate represented by the following formula (y) is triphenyl It is higher than the reduction potential of the sulfonium cation.
(Ii) 'In the case of a group represented by the following formula (x formula (x)' A in) - above is replaced with a monovalent group containing a monovalent anion represented by the octafluorobutane sulfonate group 1 represented by M + in the following formula (z ′) when the group represented by the formula (z ′) is compared with the triphenylsulfonium octafluorobutanesulfonate group represented by the following formula (y ′). The reduction potential of the valent onium cation is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A − is a monovalent anion. M + is a monovalent onium cation.
In formula (z), M + has the same meaning as in formula (x).
', A represents the formula (x)' - is a monovalent group comprising a monovalent anion. M + is synonymous with the formula (x). * Shows the site | part couple | bonded with a polymer.
In the formula (y ′), * is synonymous with the formula (x ′).
In formula (z ′), M + has the same meaning as in formula (x). * Is synonymous with the formula (x ′). )
Necessary to oxidize the value of energy (E * ) necessary to excite the radiation-sensitive sensitizer that absorbs the second radiation and the radiation-sensitive sensitizer that absorbs the second radiation. Of the photosensitized energy transfer obtained from the following formula (I) based on the value of the effective energy (E Oxi (PS) ) and the value of the energy necessary to reduce the second compound (E Red (Qu) ) The chemically amplified resist material according to claim 1 or 2, wherein the free energy (ΔG (Qu) ) is 0 kcal / mol or less.
ΔG (Qu) = (E Oxi (PS) −E Red (Qu) ) −E * (I)
Necessary to oxidize the value of energy (E * ) necessary to excite the radiation-sensitive sensitizer that absorbs the second radiation and the radiation-sensitive sensitizer that absorbs the second radiation. Of the photosensitized energy transfer obtained from the following formula (II) based on the value of the effective energy (E Oxi (PS) ) and the value of the energy necessary to reduce the first compound (E Red (PAG) ) The chemically amplified resist material according to any one of claims 1 to 3, wherein a free energy (ΔG (PAG) ) is 0 kcal / mol or less.
ΔG (PAG) = (E Oxi (PS) −E Red (PAG) ) −E * (II)
The energy released when the cation of the first compound is reduced to a radical and the energy released when the cation of the second compound is reduced to a radical are both 5.0 eV or more. 4. The chemically amplified resist material according to 4.
The first compound includes a first onium cation and a first anion, and the second compound includes a second onium cation and a second anion different from the first anion,
The chemically amplified resist material according to any one of claims 1 to 5, wherein energy released when the first onium cation and the second onium cation are reduced to radicals is 5.0 eV or more. .
The chemically amplified resist material according to claim 6, wherein the second onium cation contains a group having an electron-withdrawing substituent.
The chemically amplified resist material according to claim 1, further comprising the following component (e):
(E) When the first radiation is irradiated and the second radiation is not irradiated, the basicity of the acid generated from the component (2) is lost, and a reduction potential lower than the reduction potential of the triphenylsulfonium cation is obtained. An acid diffusion control agent.
(F) The acid diffusion control agent according to any one of claims 1 to 8, further comprising an acid diffusion controller having no radiation sensitivity and having basicity with respect to the acid generated from the component (a) or the component (c). 2. The chemically amplified resist material according to item 1.
(G) further containing a radiation sensitive photodegradable base-radiation sensitive sensitizer generator;
The component (g) is
When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the basicity against the acid generated from the component (2) is generated. Lost
When the second radiation is irradiated after the irradiation with the first radiation, the generated radiation-sensitive sensitizer absorbs the second radiation and has basicity against the acid generated from the component (2). Lost,
When only the second radiation is irradiated without irradiating the first radiation, a radiation-sensitive sensitizer is not substantially generated, and is basic to the acid generated from the component (2). Hold and
The chemically amplified resist material according to claim 1, which has a reduction potential higher than that of triphenylsulfonium.
The chemically amplified resist material according to claim 6 or 7, wherein a total content of the first onium cation and the second onium cation with respect to all onium cations in the chemically amplified resist material is 80 mol% or more.
The chemically amplified resist material according to claim 6, 7 or 11, wherein the first onium cation and the second onium cation have the same structure.
The chemically amplified resist material according to any one of claims 1 to 12, wherein a logarithmic value of an inverse number of an acid dissociation constant of an acid generated from the first compound is 0 or less.
The chemically amplified resist material according to any one of claims 1 to 13, wherein the polymer component (1) includes a first polymer having a structural unit containing a group that generates a polar group by the action of an acid. .
The first polymer has a structural unit containing a fluorine atom, or the (1) polymer component contains a second polymer different from the first polymer, and the second polymer contains a fluorine atom. The chemically amplified resist material according to claim 14, comprising a structural unit.
The chemically amplified resist material according to any one of claims 1 to 15, wherein the content of the component (2) with respect to the total solid content is 10% by mass or more and 40% by mass or less with respect to the total solid content. .
A film forming step of forming a resist material film on the substrate using the chemically amplified resist material according to any one of claims 1 to 16,
A pattern exposure step of irradiating the resist material film with radiation having a wavelength of 250 nm or less;
A batch exposure step of irradiating the resist material film after the pattern exposure step with radiation having a wavelength of more than 250 nm;
A baking step of heating the resist material film after the batch exposure step;
A resist pattern forming method comprising: a developing step of bringing the resist material film after the baking step into contact with a developer.
The resist pattern forming method according to claim 17, wherein the radiation having a wavelength of 250 nm or less is any one of KrF, ArF, EUV, or an electron beam.
(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2), and
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) is Radiation sensitivity that retains basicity with respect to the acid generated by the component (2) when the basic acid with respect to the generated acid is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base is a compound represented by the following formula (x), and the reduction potential of M + in the following formula (x) is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A − is a monovalent anion. M + is a monovalent onium cation.
(1) a polymer component that becomes soluble or insoluble in a developer by the action of an acid;
(2) a component that generates a radiation-sensitive sensitizer and an acid upon exposure;
(3) a component that is relatively basic to the acid generated by the component (2), and
The component (2) contains the following component (a), any two components in the following components (a) to (c), or all of the following components (a) to (c):
The component (a) or the component (c) has a first compound having a radiation-sensitive acid generating group,
A chemically amplified resist material wherein the component (3) contains a second compound which is the following component (d).
(A) When the first radiation that is radiation having a wavelength of 250 nm or less is irradiated and the second radiation that is radiation having a wavelength exceeding 250 nm is not irradiated, the acid and the second radiation are absorbed. A radiation-sensitive sensitizer and, when only the second radiation is irradiated without irradiation with the first radiation, the acid and radiation-sensitive sensitizer are not substantially generated. Acid-sensitizer generator.
(B) When the first radiation is irradiated and the second radiation is not irradiated, a radiation-sensitive sensitizer that absorbs the second radiation is generated, and the first radiation is irradiated. A radiation-sensitive sensitizer generating agent that does not substantially generate the radiation-sensitive sensitizer when only the second radiation is irradiated.
(C) When the first radiation is irradiated and the second radiation is not irradiated, an acid is generated, and the first radiation is not irradiated and only the second radiation is irradiated. A radiation-sensitive acid generator that does not substantially generate acid.
(D) When the first radiation is irradiated and the second radiation is not irradiated, and when the second radiation is irradiated after the first radiation is irradiated, the component (2) is Radiation sensitivity that retains basicity with respect to the acid generated by the component (2) when the basic acid with respect to the generated acid is lost and only the second radiation is irradiated without irradiation with the first radiation. Photodegradable base. However, the radiation-sensitive photodegradable base satisfies the following conditions (i) and (ii).
(I) In the case of a compound represented by the following formula (x), the reduction potential of M + in the following formula (x) is higher than the reduction potential of the triphenylsulfonium cation.
(Ii) In the case of the group represented by the following formula (x ′), the reduction potential of the monovalent onium cation represented by M + in the following formula (x ′) is higher than the reduction potential of the triphenylsulfonium cation.

(In formula (x), A − is a monovalent anion. M + is a monovalent onium cation.
', A represents the formula (x)' - is a monovalent group comprising a monovalent anion. M + is synonymous with the formula (x). * Shows the site | part couple | bonded with a polymer. )