JP6485298B2 - Radiation-sensitive resin composition and resist pattern forming method - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition and a resist pattern forming method.

  Radiation-sensitive resin compositions used for microfabrication by lithography are exposed by irradiation with far ultraviolet rays such as ArF excimer laser light and KrF excimer laser light, electromagnetic waves such as extreme ultraviolet rays (EUV), and charged particle beams such as electron beams. An acid is generated in the part, and a chemical reaction using this acid as a catalyst causes a difference in the dissolution rate in the developer between the exposed part and the unexposed part, thereby forming a pattern on the substrate.

  Such a radiation sensitive resin composition is required to improve the resist performance as the processing technique becomes finer. In response to this requirement, the types and molecular structures of polymers, acid generators and other components used in the composition have been studied, and further their combinations have been studied in detail (Japanese Patent Application Laid-Open No. 11-125907, special features). (See Kaihei 8-146610 and JP-A 2000-298347).

  At present, pattern miniaturization has progressed to a level of 40 nm or less, but the radiation sensitive resin composition has higher resist performance, especially sensitivity to exposure light such as electron beam and EUV. In addition, it is also required that the nano-edge roughness of the pattern is even smaller. However, these requirements cannot be met together.

Japanese Patent Laid-Open No. 11-125907 JP-A-8-146610 JP 2000-298347 A

  The present invention has been made based on the circumstances as described above, and its purpose is to provide a radiation-sensitive resin composition excellent in sensitivity and nanoedge roughness performance, and a resist pattern forming method using this radiation-sensitive resin composition. It is to provide.

（式（１）中、Ａｒ^１は、炭素数６〜２０の（ｍ＋１）価の芳香族炭化水素基である。ｍは、０〜１１の整数である。Ａｒ^２は、炭素数６〜２０の（ｎ＋１）価の芳香族炭化水素基である。ｎは、０〜１１の整数である。Ｒ^１及びＲ^２は、それぞれ独立して、ヒドロキシ基、スルファニル基、アミノ基又は炭素数１〜２０の１価の有機基である。ｍが２以上の場合、複数のＲ^１は同一でも異なっていてもよく、複数のＲ^１のうちの２つ以上が互いに合わせられこれらが結合する炭素鎖と共に環員数３〜２０の環構造を形成していてもよい。ｎが２以上の場合、複数のＲ^２は同一でも異なっていてもよく、複数のＲ^２のうちの２つ以上が互いに合わせられこれらが結合する炭素鎖と共に環員数３〜２０の環構造を形成していてもよい。ｍが１以上かつｎが１０以下の場合、１のＲ^１とＡｒ^２の芳香族炭化水素基の芳香環を構成する炭素原子とが互いに合わせられ、Ｒ^１が有する−Ｏ−、−Ｓ−、−ＮＲ’−又は炭素数１〜２０の有機基を介して環を形成していてもよい。Ｒ’は、水素原子又は炭素数１〜１０の１価の炭化水素基である。Ｒ^３は、酸の作用により解離する基である。） The invention made in order to solve the above problems is a first component whose solubility in a developing solution is changed by the action of an acid (hereinafter also referred to as “[A] component”), and an acid that is generated by the action of radiation. A radiation-sensitive resin composition containing two components (hereinafter also referred to as “[B] component”) and a compound represented by the following formula (1) (hereinafter also referred to as “[C] compound”).

(In Formula (1), Ar ¹ is an (m + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. M is an integer of 0 to 11. Ar ² is 6 to 20 carbon atoms. N is an integer of 0 to 11. R ¹ and R ² each independently represent a hydroxy group, a sulfanyl group, an amino group, or a carbon number of 1 to A monovalent organic group of 20. When m is 2 or more, a plurality of R ^{1 s} may be the same or different, and two or more of the plurality of R ¹ are combined with each other and bonded together. And may form a ring structure having 3 to 20 ring members, and when n is 2 or more, the plurality of R ² may be the same or different, and two or more of the plurality of R ² may be combined with each other. And a carbon chain to which these are bonded may form a ring structure having 3 to 20 ring members. If 1 or more and n is 10 or less, and the carbon atoms are combined together to form one aromatic ring of the aromatic hydrocarbon group ^{R 1} and Ar ^2, -O ^{where R 1} has -, - S -, - A ring may be formed through NR′- or an organic group having 1 to 20 carbon atoms, R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is It is a group dissociated by the action of an acid.)

  Another invention made in order to solve the above-mentioned problems is a first process comprising a step of forming a resist film on a substrate using the radiation-sensitive resin composition and a first wavelength radiation absorbed by the second component. A first exposure step of pattern exposing the resist film with exposure light, and a second exposure light containing radiation having a second wavelength longer than the first wavelength, exposing the resist film pattern-exposed with the first exposure light. A resist pattern forming method comprising: a second exposure step of developing; and a step of developing the resist film exposed with the second exposure light.

  Here, 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. “Number of ring members” means the number of atoms constituting the ring of the alicyclic structure, aromatic ring structure, aliphatic heterocyclic structure and aromatic heterocyclic structure, and in the case of polycyclic, the number of atoms constituting this polycyclic ring Say.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, a resist pattern that can exhibit high sensitivity and has a small nano edge roughness can be formed. Therefore, these can be suitably used for manufacturing semiconductor devices that are expected to be further miniaturized in the future.

(A)-(e) is a schematic diagram which shows the process of the resist pattern formation method of this embodiment. It is a figure which shows the energy irradiation amount-residual film rate curve in the resist pattern formation method of embodiment. 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.

<Radiation sensitive resin composition>
The radiation sensitive resin composition contains an [A] component, a [B] component, and a [C] compound. The radiation-sensitive resin composition may contain a [D] acid diffusion controller and / or a [E] solvent as a suitable component, and other optional components as long as the effects of the present invention are not impaired. You may contain. Hereinafter, each component will be described.

<[A] component>
The component [A] is a component whose solubility in a developer changes due to the action of an acid. The [A] component is not particularly limited as long as it has the above properties, but a polymer having an acid dissociable group (hereinafter also referred to as “[A] polymer”) is preferable. The “acid-dissociable group” refers to a group that replaces a hydrogen atom such as a carboxy group, a sulfo group, or a phenolic hydroxyl group and that dissociates by the action of an acid.

[[A] polymer]
[A] The polymer is a polymer having an acid dissociable group. [A] Since the polymer has an acid dissociable group, the acid dissociable group is dissociated by the action of an acid generated from the component [B] described later. As a result, the solubility of the [A] polymer in the developer changes, so that according to the radiation sensitive resin composition, a resist pattern can be formed.

  [A] The polymer usually has a structural unit containing an acid dissociable group (hereinafter also referred to as “structural unit (I)”). [A] In addition to the structural unit (I), the polymer has a structural unit (II) containing a phenolic hydroxyl group, a lactone structure, a cyclic carbonate structure, a sultone structure, or a structural unit (III) containing a combination thereof. And may have other structural units other than (I) to (III). [A] The polymer may have one or more of each structural unit. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit containing an acid dissociable group. 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 formula (a-1), R ⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ⁸ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁹ and R ¹⁰ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a ring number of 3 to 3 constituted by these groups combined with the carbon atom to which they are bonded. 20 alicyclic structures are represented.
In the formula ^{(a-2), R 11} is hydrogen atom or a methyl group. L ¹ is a single bond, —COO— or —CONH—. R ¹² is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ¹³ and R ¹⁴ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms.

  As the structural unit (I-1), structural units represented by the following formulas (a-1-1) to (a-1-4) (hereinafter referred to as “structural units (I-1-1) to (I-1) -4) ") is preferred. As the structural unit (I-2), a structural unit represented by the following formula (a-2-1) (hereinafter also referred to as “structural unit (I-2-1)”) is preferable.

R < ⁷ > -R < ¹⁰ > is synonymous with the said Formula (a-1) in said Formula (a-1-1)-(a-1-4). i is an integer of 1-4 independently of each other.
In the formula ^{(a-2-1), R 11} ~R 14 is as defined in the above formula (a-2).

  Examples of the structural unit (I-1) include a structural unit represented by the following formula.

In said formula, R < ⁷ > is synonymous with the said Formula (a-1).

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

In said formula, R < ¹¹ > is synonymous with the said Formula (a-2).

  As the structural unit (I-1), the structural unit (I-1-2) and the structural unit (I-1-3) are preferable, and the structural unit is derived from 1-alkylcyclopentan-1-yl (meth) acrylate. And a structural unit derived from 2- (adamantan-1-yl) propan-2-yl (meth) acrylate is more preferable. The structural unit (II-2) is preferably a structural unit (II-2-1), more preferably a structural unit derived from 1-oxyhydrocarbon-substituted-1-alkyloxystyrene, and 1-cycloalkyloxy-1 -A structural unit derived from alkyloxystyrene is more preferable, and a structural unit derived from 1-cyclohexylethyloxy-1-ethyloxystyrene is particularly preferable.

  As a minimum of the content rate of structural unit (I), 10 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 20 mol% is more preferable, 30 mol% is further more preferable, 40 mol% % Is particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 60 mol% is further more preferable, 55 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, a sensitivity and nanoedge roughness performance can be improved more.

[Structural unit (II)]
The structural unit (II) is a structural unit containing a phenolic hydroxyl group. [A] By further having the structural unit (II), the polymer can adjust the solubility in the developer more appropriately, and as a result, the nano edge roughness performance can be further improved. In addition, the adhesion of the pattern to the substrate can be improved. Furthermore, in the case of KrF exposure, EUV exposure or electron beam exposure, the sensitivity can be further increased.

  Examples of the structural unit (II) include a structural unit represented by the following formula (a-3) (hereinafter also referred to as “structural unit (II-1)”).

In the above formula (a-3), R ¹⁵ represents a hydrogen atom or a methyl group. L ² is a single bond or a divalent organic group having 1 to 20 carbon atoms. R ¹⁶ is a monovalent organic group having 1 to 20 carbon atoms. p is an integer of 0-2. q is an integer of 0-9. When q is 2 or more, the plurality of R ¹⁶ may be the same or different. r is an integer of 1 to 3.

  Examples of the structural unit (II) include structural units represented by the following formulas (a-3-1) to (a-3-7) (hereinafter, “structural units (II-1) to (II-7)”). Also).

In the formulas (a-3-1) to (a-3-7), R ¹⁵ has the same meaning as the formula (a-3).

  Of these, the structural unit (II-1) is preferable.

  [A] When the polymer has the structural unit (II), the content of the structural unit (II) is preferably 10 mol%, preferably 30 mol%, based on all structural units constituting the [A] polymer. Is more preferable, and 45 mol% is more preferable. As an upper limit of the said content rate, 80 mol% is preferable, 60 mol% is more preferable, and 55 mol% is further more preferable. By making the content rate of structural unit (II) into the said range, nano edge roughness performance can further be improved. In addition, the sensitivity in the case of KrF exposure, EUV exposure, or electron beam exposure can be further increased.

[Structural unit (III)]
The structural unit (III) is a structural unit including a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. [A] Since the polymer further has the structural unit (III), the solubility in the developer can be further adjusted, and as a result, the nano edge roughness performance can be further improved. Further, the adhesion between the pattern and the substrate can be further improved.

  Examples of the structural unit (III) include a structural unit represented by the following formula.

In the above formula, R ^L1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  Among these, the structural unit (III) is preferably a structural unit containing a lactone structure, more preferably a structural unit containing a norbornane lactone structure or a structural unit derived from cyanonorbornane lactone-yl (meth) acrylate.

  [A1] When the polymer has the structural unit (III), the lower limit of the content ratio of the structural unit (III) is preferably 5 mol% with respect to all the structural units constituting the [A] polymer. Mole% is more preferable, and 40 mol% is more preferable. As an upper limit of the said content rate, 70 mol% is preferable, 60 mol% is more preferable, and 55 mol% is further more preferable. By making the said content rate into the said range, nano edge roughness performance can further be improved. Further, the adhesion of the pattern to the substrate can be further improved.

[Other structural units]
[A] The polymer may have other structural units in addition to the structural units (I) to (III). 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. As an upper limit of the content rate of another structural unit, 20 mol% is preferable and 10 mol% is more preferable.

  [A] As a minimum of polystyrene conversion weight average molecular weight (Mw) by gel permeation chromatography (GPC) of a polymer, 2,000 is preferred, 4,000 is more preferred, 5,500 is still more preferred, 500 is particularly preferred. The upper limit of Mw is preferably 50,000, more preferably 20,000, still more preferably 10,000, and particularly preferably 9,000. [A] By making Mw of a polymer into the said range, a sensitivity and nanoedge roughness performance can be improved more.

  [A1] The upper 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 5, more preferably 3, and even more preferably 2. The lower limit of the ratio is usually 1 and is preferably 1.3.

Mw and Mn of the polymer in this specification are values measured using GPC under the following conditions.
GPC column: For example, two “G2000HXL”, one “G3000HXL” and one “G4000HXL” manufactured by Tosoh Corporation Column temperature: 40 ° C.
Elution solvent: Tetrahydrofuran (Wako Pure Chemical Industries)
Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

  [A] The lower limit of the content of the polymer is preferably 70% by mass, more preferably 80% by mass, and still more preferably 85% by mass with respect to the total solid content of the radiation-sensitive resin composition. The “total solid content” of the radiation-sensitive resin composition refers to the sum of components other than the [E] solvent.

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized, for example, by polymerizing monomers that give each structural unit in a suitable solvent using a radical polymerization initiator or the like.

  Examples of radical polymerization initiators include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropio). Nitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), azo radical initiators such as dimethyl 2,2′-azobisisobutyrate; benzoyl peroxide, t-butyl hydroperoxide, cumene And peroxide radical initiators such as hydroperoxide. Of these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, and AIBN is more preferred. These radical initiators can be used alone or in combination of two or more.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;
Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate;
Ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethane, diethoxyethane;
Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. The solvent used for these polymerizations may be used alone or in combination of two or more.

  As a minimum of reaction temperature in superposition | polymerization, 40 degreeC is preferable and 50 degreeC is more preferable. As an upper limit of the said reaction temperature, 150 degreeC is preferable and 120 degreeC is more preferable. As a minimum of reaction time in a polymer, 1 hour is preferred and 2 hours is more preferred. The upper limit of the reaction time is preferably 48 hours, more preferably 24 hours.

<[B] component>
The component [B] is a component that generates an acid by the action of radiation. “Acid is generated by the action of radiation” means that the sensitizer generated from the [C] compound described later, in addition to the fact that the [B] component decomposes by directly absorbing exposure light to generate acid. It also includes generating an acid by absorbing the exposure light and decomposing the [B] component by giving and receiving the absorbed energy. The generated acid dissociates the acid-dissociable group of the [A] component to produce a carboxy group, a phenolic hydroxyl group, etc., and the solubility of the [A] component in the developer changes, thus forming a resist pattern. can do. In the radiation-sensitive resin composition, the [B] component is contained in a form of a low-molecular-weight radiation-sensitive acid generator (hereinafter also referred to as “[B] acid generator”). It may be in the form of a polymer having a group to form, or both of these forms.

[[B] acid generator]
[B] Examples of the acid generator include onium salt compounds, N-sulfonyloxyimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  [B] Specific examples of the acid generator include compounds described in paragraphs [0080] to [0113] of JP-A-2009-134088.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept- 2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate, triphenylsulfonium camphorsulfonate, 4 -Cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexyl Phenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyl Diphenylsulfonium camphorsulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonyl Phenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafur B ethanesulfonate, 4-methanesulfonyl-phenyl camphorsulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro-6- (1-adamantanecarbonyloxy) - hexane-1-sulfonate, and the like.

  Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nona. Fluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophene Ni-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate , 1- (6-n-butoxynaphthalen-2-yl) Torahydrothiophenium trifluoromethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydro Thiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium camphorsulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate , 1- (3,5-dimethyl-4 Hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl- 4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxy Phenyl) tetrahydrothiophenium camphorsulfonate and the like.

  Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonate, diphenyliodonium camphorsulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, Bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2 1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t- butylphenyl) iodonium camphorsulfonate, and the like.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy). ) Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2 , 3-dicarboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept- 5-ene-2,3-dicarboximide, N- (2- (3- tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoro-ethanone Sulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3 -Dicarboximide etc. can be mentioned.

  [B] Examples of the acid generator include an acid generator represented by the following formula (3). [B] Since the acid generator has the following structure, the diffusion length of the acid generated by exposure in the resist film due to the interaction with the structural unit (I) of the polymer and the like is reasonably short. As a result, the nano edge roughness performance can be further improved.

In the above formula (3), 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. Y ⁺ is a monovalent radiation-sensitive onium cation.

Examples of the monovalent group including a ring structure having 6 or more ring members represented by R ^p1 include a monovalent group including an alicyclic structure having 6 or more ring members and an aliphatic heterocyclic structure having 6 or more ring members. A monovalent group, a monovalent group containing an aromatic ring structure having 6 or more ring members, a monovalent group containing an aromatic heterocyclic structure having 6 or more ring members, and the like.

Examples of the alicyclic structure having 6 or more ring members include monocyclic cycloalkane structures such as a cyclohexane structure, a cycloheptane structure, a cyclooctane structure, a cyclononane structure, a cyclodecane structure, and a cyclododecane structure;
Monocyclic cycloalkene structures such as cyclohexene structure, cycloheptene structure, cyclooctene structure, cyclodecene structure;
Polycyclic cycloalkane structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;
Examples thereof include polycyclic cycloalkene structures such as a norbornene structure and a tricyclodecene structure.

Examples of the aliphatic heterocyclic structure having 6 or more ring members include lactone structures such as a hexanolactone structure and a norbornane lactone structure;
Sultone structures such as hexanosultone structure and norbornane sultone structure;
An oxygen atom-containing heterocyclic structure such as an oxacycloheptane structure or an oxanorbornane structure;
Nitrogen atom-containing heterocyclic structures such as azacyclohexane structure and diazabicyclooctane structure;
Examples thereof include a sulfur atom-containing heterocyclic structure having a thiacyclohexane structure and a thianorbornane structure.

  Examples of the aromatic ring structure having 6 or more ring members include a benzene structure, a naphthalene structure, a phenanthrene structure, and an anthracene structure.

  Examples of the aromatic heterocyclic structure having 6 or more ring members include oxygen atom-containing heterocyclic structures such as furan structure, pyran structure and benzopyran structure, nitrogen atom-containing heterocyclic structures such as pyridine structure, pyrimidine structure and indole structure. Can be mentioned.

The lower limit of the number of ring members of the ring structure of R ^p1 is preferably 7, more preferably 8, more preferably 9, and particularly preferably 10. On the other hand, the upper limit of the number of ring members is preferably 15, more preferably 14, still more preferably 13, and particularly preferably 12. By setting the number of ring members in the above range, the acid diffusion length can be further appropriately shortened, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved.

A part or all of the hydrogen atoms ^{contained in} the ring structure of R ^p1 may be substituted with a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, Examples include an acyloxy group. Of these, a hydroxy group is preferred.

Among these, R ^p1 is preferably a monovalent group containing an alicyclic structure having 6 or more ring members and a monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members, and an alicyclic group having 9 or more ring members. A monovalent group containing a ring structure and a monovalent group containing an aliphatic heterocyclic structure having 9 or more ring members are more preferable, and an adamantyl group, a hydroxyadamantyl group, a norbornanelactone-yl group, a norbornane sultone-yl group, and 5- An oxo-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-yl group is more preferred, and an adamantyl group is particularly preferred.

Examples of the divalent linking group represented by R ^p2 include a carbonyl group, an ether group, a carbonyloxy group, a sulfide group, a thiocarbonyl group, a sulfonyl group, and a divalent hydrocarbon group. The divalent linking group represented by R ^p2 is preferably a carbonyloxy group, a sulfonyl group, an alkanediyl group and a cycloalkanediyl group, more preferably a carbonyloxy group and a cycloalkanediyl group, a carbonyloxy group and a norbornanediyl group. A group is more preferred, and a carbonyloxy group is particularly preferred.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^p3 and R ^p4 include an alkyl group having 1 to 20 carbon atoms. Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ^p3 and R ^p4 include a fluorinated alkyl group having 1 to 20 carbon atoms. R ^p3 and R ^p4 are preferably a hydrogen atom, a fluorine atom and a fluorinated alkyl group, more preferably a fluorine atom and a perfluoroalkyl group, and still more preferably a fluorine atom and a trifluoromethyl group.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ^p5 and R ^p6 include a fluorinated alkyl group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are preferably a fluorine atom and a fluorinated alkyl group, more preferably a fluorine atom and a perfluoroalkyl group, still more preferably a fluorine atom and a trifluoromethyl group, and particularly preferably a fluorine atom.

The n ^p1, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, more preferably an integer of 0 to 2, 0 and 1 are particularly preferred.

The n ^p2, preferably an integer of 0 to 5, more preferably an integer of 0 to 2, more preferably 0 and 1, 0 being particularly preferred.

As ^np3 , the integer of 1-5 is preferable, the integer of 1-4 is more preferable, the integer of 1-3 is more preferable, and 1 and 2 are especially preferable.

The monovalent radiation-sensitive onium cation represented by Y ⁺ is a cation that decomposes upon exposure to exposure light. In the exposed portion, sulfonic acid is generated from protons generated by the decomposition of the radiation-sensitive onium cation and sulfonate anions. Examples of the monovalent radiation-sensitive onium cation include a cation represented by the following formula (Y-1) (hereinafter also referred to as “cation (Y-1)”) and the following formula (Y-2). Cations (hereinafter also referred to as “cation (Y-2)”), cations represented by the following formula (Y-3) (hereinafter also referred to as “cation (Y-3)”), and the like.

In the above formula (Y-1), R ^a1 , R ^a2 and R ^a3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, substituted or unsubstituted. aromatic hydrocarbon group having 6 to 12 carbon atoms, a or a -OSO ₂ -R ^P or _-SO 2 -R ^Q, or two or more are combined with each other configured ring of these groups . R ^P and R ^Q are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k1, k2 and k3 are each independently an integer of 0 to 5. R ^a1 to R ^a3 and when ^{R P} and ^{R Q} are a plurality each of the plurality of ^R a1 ^{to R a3} and ^{R P} and ^{R Q} may be the same as or different from each other.

In the above formula (Y-2), R ^b1 represents a substituted or unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon having 6 to 8 carbon atoms. It is a group. k4 is an integer of 0-7. If R ^b1 is plural, the plurality of R ^b1 may be the same or different, and plural R ^b1 may represent a constructed ring aligned with each other.
R ^b2 is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0-6. If R ^b2 is plural, the plurality of R ^b2 may be the same or different, and plural R ^b2 may represent a keyed configured ring structure. r is an integer of 0-3. R ^b3 is a single bond or a divalent organic group having 1 to 20 carbon atoms. t is an integer of 0-2.

In the above formula (Y-3), R ^c1 and R ^c2 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted carbon number of 6 12 aromatic hydrocarbon group, or an -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k6 and k7 are each independently an integer of 0 to 5. R ^{c1, R} c2, ^R when ^R and ^{R S} is plural respective plurality of ^{R c1,} R c2, ^{R R} and ^{R S} may have respectively the same or different.

Examples of the unsubstituted linear alkyl group represented by R ^{a1 to} R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. Is mentioned.

Examples of the unsubstituted branched alkyl group represented by R ^{a1 to} R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include i-propyl group, i-butyl group, sec-butyl group, t- A butyl group etc. are mentioned.

Examples of the unsubstituted aromatic hydrocarbon group represented by R ^{a1 to} R ^a3 , R ^c1 and R ^c2 include aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group and naphthyl group; benzyl group and phenethyl group And an aralkyl group such as a group.

Examples of the unsubstituted aromatic hydrocarbon group represented by R ^b1 and R ^b2 include a phenyl group, a tolyl group, and a benzyl group.

Examples of the divalent organic group represented by R ^b3 include the same groups as those exemplified as the divalent organic group of L ^{1 in} the above formula (3).

  Examples of the substituent that may be substituted for the hydrogen atom of the alkyl group and the aromatic hydrocarbon group include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, a hydroxy group, a carboxy group, a cyano group, Examples thereof include a nitro group, an alkoxy group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an acyl group, and an acyloxy group. Among these, a halogen atom is preferable and a fluorine atom is more preferable.

R ^{a1 to} R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include an unsubstituted linear or branched alkyl group, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, —OSO ₂ —R ″ and —SO ₂ —R ″ are preferred, fluorinated alkyl groups and unsubstituted monovalent aromatic hydrocarbon groups are more preferred, and fluorinated alkyl groups are more preferred. R ″ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

  As k1, k2, and k3 in Formula (Y-1), integers of 0 to 2 are preferable, 0 and 1 are more preferable, and 0 is more preferable. As k4 in Formula (X-2), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 1 is more preferable. k5 is preferably an integer of 0 to 2, more preferably 0 and 1, and still more preferably 0. As r, 2 and 3 are preferable, and 2 is more preferable. As t, 0 and 1 are preferable, and 0 is more preferable. As k6 and k7 in Formula (Y-3), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 0 is more preferable.

Among these, as Y ⁺ , a cation (Y-1) and a cation (Y-3) are preferable, and a triphenylsulfonium cation and a diphenyliodonium cation are more preferable.

  [B] Examples of the acid generator include compounds represented by the following formulas (3-1) to (3-16) (hereinafter also referred to as “compounds (3-1) to (3-16)”). It is done.

In the above formulas (3-1) to (3-16), Y ⁺ is a monovalent radiation-sensitive onium cation.

  [B] The acid generator is preferably an onium salt compound, more preferably compounds (3-15) and (3-16), and still more preferably compound (3-16).

[Polymer having acid-generating group]
Examples of the polymer having a group capable of generating an acid of [B] include a polymer having a structural unit represented by the following formula (4).

In the formula ^{(4), R 17} is a hydrogen atom or a methyl group. L ³ is a single bond, —COO—, a substituted or unsubstituted divalent hydrocarbon group, a substituted or unsubstituted divalent carbonyloxy hydrocarbon group, or a substituted or unsubstituted sulfonyloxy hydrocarbon group. R ¹⁸ is a fluorinated alkanediyl group having 1 to 10 carbon atoms. Y ⁺ is a monovalent radiation-sensitive onium cation.

  When the component [B] is a [B] acid generator, the lower limit of the content of the [B] acid generator is preferably 0.1 part by weight with respect to 100 parts by weight of the component [A], and 1 part by weight. Is more preferable, 5 parts by mass is more preferable, 10 parts by mass is particularly preferable, and 15% by mass is further particularly preferable. As an upper limit of the said content, 50 mass parts is preferable, 40 mass parts is more preferable, and 30 mass parts is further more preferable. [B] By making content of an acid generator into the said range, a sensitivity can further be improved. As a result, the nano edge roughness performance can be further improved. [B] A component can use 1 type (s) or 2 or more types.

<[C] Compound>
[C] The compound is a compound represented by the following formula (1).

In the above formula (1), Ar ¹ is an (m + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. m is an integer of 0-11. Ar ² is an (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. n is an integer of 0 to 11. R ¹ and R ² are each independently a hydroxy group, a sulfanyl group, an amino group, or a monovalent organic group having 1 to 20 carbon atoms. When m is 2 or more, the plurality of R ¹ may be the same or different, and a ring structure having 3 to 20 ring members is formed together with a carbon chain in which two or more of the plurality of R ¹ are combined with each other. It may be formed. when n is 2 or more, plural R ² may be the same or different, two or more are combined with each other ring ring members 3 to 20 together with the carbon chain to which they are attached among the plurality of R ² It may be formed. When m is 1 or more and n is 10 or less, R ^{1 of 1} and the carbon atom constituting the aromatic ring of the aromatic hydrocarbon group of Ar ² are combined with each other, and R ¹ has —O—, —S—. , —NR′— or an organic group having 1 to 20 carbon atoms may form a ring. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ³ is a group that is dissociated by the action of an acid.

As represented by the following scheme, the [C] compound gives a diarylamine structure by dissociating R ³ (group dissociated by the action of an acid) by the action of an acid (H ⁺ ).

  According to this diarylamine structure, a function as a sensitizer that absorbs ultraviolet light of 365 nm or the like and gives the absorbed energy to the [B] component can be exhibited. Therefore, according to the radiation sensitive resin composition, an acid is generated from the [B] component by exposure with exposure light such as EUV, and a sensitizer is generated from the [C] compound by the action of this acid. Next, by irradiating with ultraviolet light using an exposure machine equipped with a high-pressure mercury lamp, an acid can be effectively generated from the [B] component by the action of this sensitizer. That is, the radiation sensitive resin composition can exhibit high sensitivity. As a result, the nano edge roughness performance can be improved.

Examples of the (m + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by Ar ¹ and the (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by Ar ² include carbon. Examples include groups obtained by removing 1 to 12 hydrogen atoms from an aromatic hydrocarbon group of several 6 to 20.

  Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include benzene, naphthalene, anthracene, phenanthrene, phenalene, triphenylene, pyrene, chrysene, tetracene, and perylene.

  As m and n, the integer of 0-2 is preferable, 0 and 1 are preferable and 0 is more preferable.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ and R ² include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms and a divalent hydrocarbon between carbon-carbon of the hydrocarbon group. Examples include a group (α) containing a heteroatom-containing group, a group obtained by substituting part or all of the hydrogen atoms of the hydrocarbon group and the group (α) with a monovalent heteroatom-containing group.

  Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and 6 to 6 carbon atoms. 20 monovalent aromatic hydrocarbon groups and the like.

Examples of the monovalent chain hydrocarbon group having 1 to 20 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 20 carbon atoms include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group;
A monocyclic cycloalkenyl group such as a cyclopentenyl group and a cyclohexenyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group and a tricyclodecyl group;
Examples thereof include polycyclic cycloalkenyl groups such as norbornenyl group and tricyclodecenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group and anthrylmethyl group.

  Examples of the hetero atom constituting the monovalent and divalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, and a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Examples of the divalent heteroatom-containing group include —O—, —CO—, —S—, —CS—, —NR′—, a group in which two or more of these are combined, and the like. R 'is a hydrogen atom or a monovalent hydrocarbon group. Of these, -O- is preferred.

  Examples of the monovalent heteroatom-containing group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, amino group and sulfanyl group (—SH). Among these, a fluorine atom is preferable.

As R ¹ and R ² , a hydroxy group, a sulfanyl group and an amino group are preferable, and a sulfanyl group is more preferable.

Examples of the ring structure having 3 to 20 ring members that two or more of R ¹ or two or more of R ² may form include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, Cycloaliphatic structures such as cyclohexane structure, cyclooctane structure, norbornane structure, adamantane structure, cyclopentene structure, cyclohexene structure;
Examples thereof include aromatic ring structures such as benzene structure, naphthalene structure, anthracene structure, and phenanthrene structure.

When m is 1 or more and n is 10 or less, R ^{1 of 1} and the carbon atom constituting the aromatic ring of the aromatic hydrocarbon group of Ar ² are combined with each other, and —O—, —S—, —NR ′ Examples of the ring structure formed through an organic group having 1 to 20 carbon atoms include a phenoxazine structure, a phenothiazine structure, a dihydrophenazine structure, and a dihydroacridine structure. Among these, a phenoxazine structure and a phenothiazine structure are preferable, and a phenothiazine structure is more preferable.

  R ′ is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms and a group dissociated by the action of an acid.

The group dissociated by the action of the acid represented by R ³ is not particularly limited as long as it has this property. For example, a group represented by the following formula (2) (hereinafter referred to as “group (2)”) And the like).

In the above formula (2), ^{R 4} is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁵ and R ⁶ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, or are configured together with a carbon atom to which the hydrocarbon groups are combined with each other and bonded to each other. An alicyclic structure having 3 to 20 ring members is represented. * Shows the site | part couple | bonded with the nitrogen atom in the said Formula (1).

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁴ , R ⁵ and R ⁶ include the same groups as the hydrocarbon groups exemplified as R ¹ and R ² above.

Examples of the alicyclic structure having 3 to 20 ring members formed by combining the hydrocarbon groups of R ⁵ and R ⁶ with each other include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, and a cyclooctane structure. Monocyclic cycloalkane structures such as
Polycyclic cycloalkane structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;
Monocyclic cycloalkene structures such as cyclopropene structure, cyclobutene structure, cyclopentene structure, cyclohexene structure, cycloheptene structure, cyclooctene structure;
Examples thereof include polycyclic cycloalkene structures such as a norbornene structure, a tricyclodecene structure, and a tetracyclododecene structure.

As R ⁴ , a chain hydrocarbon group and an aromatic hydrocarbon group are preferable, an alkyl group and an aryl group are more preferable, and a methyl group and a phenyl group are more preferable.

As R ⁵ and R ⁶ , a hydrogen atom and a chain hydrocarbon group are preferable, a hydrogen atom and an alkyl group are preferable, and a hydrogen atom and a methyl group are more preferable.

  Examples of the group (2) include a t-butyl group, a t-amyl group, a 1-methylcyclopentan-1-yl group, a 2-ethyladamantan-2-yl group, and a benzyl group. Among these, a t-butyl group and a benzyl group are preferable.

  Examples of the [C] compound include compounds represented by the following formula (1-1).

In the above formula ^{(1-1), R 1, R} 2, R 3, m and n have the same meanings as in formula (1). X is O, S or NR ′. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. When R ¹ is plural, a plurality of R ¹ may be the same or different. When R ² is plural, the plurality of R ² may be the same or different. a and b are each independently an integer of 0 to 3;

  As said X, O and S are preferable and S is more preferable.

  As a and b, the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is further more preferable.

  Examples of the compound [C] include compounds represented by the following formulas (c1) to (c12) (hereinafter also referred to as “compounds (c1) to (c12)”).

  Of these, compounds (c1) to (c6) are preferred.

  Compounds (c1) and (c4) generate phenothiazine by the action of an acid generated from the [B] acid generator, as represented by the following scheme. This phenothiazine can be a sensitizer that absorbs ultraviolet light such as an exposure machine equipped with a high-pressure mercury lamp and effectively generates an acid from the [B] component.

  [C] The lower limit of the content of the compound is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, further preferably 1 part by mass, with respect to 100 parts by mass of the component [A]. Is particularly preferred. As an upper limit of the said content, 30 mass parts is preferable, 20 mass parts is more preferable, 10 mass parts is further more preferable, 7 mass parts is especially preferable. [C] By making content of a compound into the said range, the sensitivity and nano edge roughness performance of the said radiation sensitive resin composition can further be improved.

<Method for Producing [C] Compound>
The [C] compound is obtained by, for example, reacting a hydrogen atom bonded to a nitrogen atom of a diarylamine compound having a structure of (R ¹ ) _m —Ar ¹ —NH—Ar ² — (R ² ) _n by a known reaction with R ³ It can synthesize | combine by substituting to the group dissociated by the effect | action of the acid represented by. As a compound for such a reaction, when R ³ is —COOR ′ and R ′ is a hydrocarbon group, for example, an acid anhydride compound represented by (R′OCO) ₂ O, R′OCOZ (Z is And acid halide compounds represented by (halogen atom). [C] As shown in the following scheme, the compound [C] is a diarylamine compound such as phenothiazine and the acid anhydride compound or acid halide compound in a solvent such as methylene chloride in the presence of a base such as dimethylaminopyridine. It can synthesize | combine by making it react with.

<[D] Acid diffusion controller>
[D] The acid diffusion controller controls the diffusion phenomenon in the resist film of the acid generated from the [B] acid generator by exposure, and has an effect of suppressing an undesirable chemical reaction in the non-exposed region. In addition, the storage stability of the radiation-sensitive composition is further improved, and the resolution as a resist is further improved. Furthermore, a change in the line width of the resist pattern due to fluctuations in the holding time from exposure to development processing can be suppressed, and a radiation-sensitive composition excellent in process stability can be obtained. [D] The content of the acid diffusion controller in the radiation-sensitive resin composition is incorporated as part of the polymer even in the form of a low molecular compound (hereinafter referred to as “[D] acid diffusion controller” as appropriate). Or both of these forms.

  [D] As the acid diffusion controller, for example, a compound represented by the following formula (5) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound (I)”) "Nitrogen-containing compound (II)"), compounds having three nitrogen atoms (hereinafter also referred to as "nitrogen-containing compound (III)"), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc. It is done.

In said formula (5), R <^19> , R <^20> and R <^21> are respectively independently a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group.

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tri-n-pentylamine; and fragrances such as aniline Group amines and the like.

  Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, and the like.

  Examples of the nitrogen-containing compound (III) include polyamine compounds such as polyethyleneimine and polyallylamine; polymers such as dimethylaminoethylacrylamide.

  Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. It is done.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea and the like.

  Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N- (undecan-1-ylcarbonyloxyethyl) morpholine; pyrazine, pyrazole and the like. .

  Moreover, the compound which has an acid dissociable group can also be used as said nitrogen-containing compound. Examples of the nitrogen-containing compound having such an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2- Phenylbenzimidazole, N- (t-butoxycarbonyl) di-n-octylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine and the like can be mentioned.

  [D] As the acid diffusion controller, a photodegradable base that is sensitized by exposure can also be used. The photodegradable base exhibits acid diffusion controllability due to its basicity in the unexposed area, but loses acid diffusion controllability in the exposed area because the basicity is reduced by the acid generated by decomposition by exposure. Examples of the photodegradable base include onium salt compounds. Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (6-1), an iodonium salt compound represented by the following formula (6-2), and the like.

In formulas (6-1) and (6-2), R ^{22 to} R ²⁶ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, or a halogen atom. E ⁻ and Q ⁻ are each independently an anion represented by OH ⁻ , R ^β —COO ⁻ , R ^β —SO ₃ ^— or the following formula (6-3). ^Rβ is an alkyl group, an aryl group, or an aralkyl group.

In the above formula ^{(6-3), R 27} is an alkyl group, a fluorinated alkyl group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms having 1 to 12 carbon atoms. u is an integer of 0-2. When u is 2, two R ²⁷ may be the same or different.

  Examples of the photodegradable base include compounds represented by the following formulas.

  Of these, the photodegradable base is preferably a sulfonium salt, more preferably a triarylsulfonium salt, and even more preferably triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate.

  When the said radiation sensitive resin composition contains a [D] acid diffusion control agent, as a minimum of content of a [D] acid diffusion control agent, it is 0.1 mass with respect to 100 mass parts of [A] component. Part is preferred, 0.5 part by weight is more preferred, and 1 part by weight is even more preferred. The upper limit of the content is preferably 20 parts by mass, more preferably 10 parts by mass, further preferably 5 parts by mass, and particularly preferably 3 parts by mass. [D] By making content of an acid diffusion control agent into the said range, the resolution of a radiation sensitive resin composition, nano edge roughness performance, etc. can be improved more.

<[E] solvent>
The radiation-sensitive resin composition usually contains an [E] solvent. [E] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the [A] component, the [B] component, the [C] compound, and the optionally contained [D] acid diffusion controller.

  [E] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

Examples of alcohol solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , Sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec -Monoalcohol solvents such as heptadecyl alcohol, furfuryl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 -Polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether.

Examples of ether solvents include dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
And aromatic ring-containing ether solvents such as diphenyl ether and anisole.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, Linear ketone solvents such as di-iso-butyl ketone and trimethylnonanone;
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone;
2,4-pentanedione, acetonylacetone, acetophenone and the like can be mentioned.

Examples of the amide solvent include cyclic amide solvents such as N, N′-dimethylimidazolidinone and N-methylpyrrolidone;
Examples thereof include chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide.

Examples of the ester solvent include methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, i-pentyl acetate, sec -Acetate solvents such as pentyl, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate;
Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether Polyhydric alcohol partial ether acetate solvents such as acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate;
Carbonate solvents such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate;
lactone solvents such as γ-butyrolactone and δ-valerolactone;
Glycol acetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl acetoacetate, ethyl acetoacetate, methyl lactate, ethyl lactate N-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate and the like.

Examples of the hydrocarbon solvent include n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, and cyclohexane. , Aliphatic hydrocarbon solvents such as methylcyclohexane;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene and n-amylnaphthalene Group hydrocarbon solvents and the like.

  Of these, ester solvents are preferred, polyhydric alcohol partial ether acetate solvents and lactone solvents are more preferred, and propylene glycol monomethyl ether acetate and γ-butyrolactone are even more preferred. [E] 1 type (s) or 2 or more types can be used for a solvent.

<Other optional components>
The radiation-sensitive resin composition may contain, for example, a fluorine atom-containing polymer, a surfactant and the like as other optional components in addition to the components [A] to [E]. The radiation-sensitive resin composition may contain one or more other optional components.

[Fluorine atom-containing polymer]
The fluorine atom-containing polymer is a polymer having a higher fluorine atom content than the component [A]. When the radiation-sensitive resin composition contains a fluorine atom-containing polymer, when the resist film is formed, the distribution is unevenly distributed near the resist film surface due to the oil-repellent characteristics of the fluorine atom-containing polymer in the resist film. It is possible to prevent the acid generator, the acid diffusion controller and the like from being eluted into the immersion medium during immersion exposure. Further, due to the water-repellent characteristics of this fluorine atom-containing polymer, the advancing contact angle between the resist film and the immersion medium can be controlled within a desired range, and the occurrence of bubble defects can be suppressed. Furthermore, the receding contact angle between the resist film and the immersion medium is increased, and high-speed scanning exposure is possible without leaving water droplets. Thus, the said radiation sensitive resin composition can form the resist film suitable for an immersion exposure method by further containing a fluorine atom containing polymer.

  As a minimum of content of a fluorine atom content polymer, 0.1 mass part is preferred to 100 mass parts of [A] ingredient, 0.5 mass part is more preferred, and 1 mass part is still more preferred. As an upper limit of the said content, 20 mass parts is preferable, 15 mass parts is more preferable, and 10 mass parts is further more preferable.

[Surfactant]
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate; commercially available products include KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, Tochem Products), MegaFuck F171, F173 (above, DIC), Florard FC430, FC431 (above, Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, Asahi Glass Industrial Co., Ltd.) Can be mentioned. As an upper limit of content of the said surfactant, 2 mass parts is preferable with respect to 100 mass parts of [A] polymers.

  The radiation sensitive resin composition can be preferably used particularly for extreme ultraviolet (EUV, vacuum ultraviolet) exposure and electron beam exposure. Since the conventional radiation sensitive resin composition has insufficient sensitivity to EUV and electron beam and nano edge roughness performance, the benefit of using the present invention is particularly great.

<Method for preparing radiation-sensitive resin composition>
The radiation-sensitive resin composition is obtained by, for example, mixing [A] component, [B] component, [C] compound, [E] solvent and other optional components as necessary, in a predetermined ratio. The obtained mixture can be prepared by filtering with a membrane filter having a pore size of about 0.2 μm. As a minimum of solid content concentration of the radiation sensitive resin composition, 0.1 mass% is preferred, 0.5 mass% is more preferred, 1 mass% is still more preferred, and 1.5 mass% is especially preferred. The upper limit of the solid content concentration is preferably 50% by mass, more preferably 30% by mass, further preferably 10% by mass, and particularly preferably 5% by mass.

  The radiation-sensitive resin composition can be used for forming a positive pattern using an alkaline developer and for forming a negative pattern using a developer containing an organic solvent.

<Resist pattern formation method>
The resist pattern forming method includes a step of forming a resist film on a substrate using the radiation-sensitive resin composition described above (hereinafter also referred to as “resist film forming step”), and a step [B] component absorbs. A first exposure step (hereinafter, referred to as pattern exposure) of the resist film with a first exposure light (hereinafter also referred to as “exposure light (I)”) containing radiation of one wavelength (hereinafter also referred to as “wavelength (I)”). "Exposure step (1)") and second exposure light (hereinafter "exposure light (II)" including radiation having a second wavelength longer than wavelength (I) (hereinafter also referred to as "wavelength (II)"). A second exposure step (hereinafter also referred to as “exposure step (2)”) for exposing the resist film exposed with the exposure light (I), and a resist exposed with the exposure light (II). And a step of developing the film.
In the resist pattern forming method, in the exposure step (2), it is preferable that no acid is substantially generated from the [B] component in a region where the exposure light (I) is not irradiated in the exposure step (1). In the resist pattern forming method, as described later, usually, in the exposure step (1), a sensitizer is produced from the [C] compound by the action of the acid generated from [B], and the exposure step. In (2), acid is generated from the component [B] by the action of the sensitizer in the exposed portion exposed in the exposure step (1).

  According to the resist pattern forming method, since the radiation sensitive resin composition described above is used, it is possible to form a resist pattern with a small nano edge roughness while exhibiting high sensitivity. Hereinafter, each step will be described.

[Resist film forming step]
First, as shown in FIG. 1A, a resist film 12 is formed on one surface side of a substrate 11 in a resist film forming step (S101). Specifically, the resist film 12 is formed by preparing a substrate 11 (for example, a wafer), applying a radiation-sensitive resin composition on the substrate 11 and performing pre-baking.

  Examples of the method for applying the radiation sensitive resin composition include spin coating, roll coating, and dipping. As a minimum of prebaking temperature, 50 ° C is preferred and 80 ° C is more preferred. As an upper limit of the temperature of prebaking, 150 degreeC is preferable and 120 degreeC is more preferable. The lower limit of the pre-baking time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the pre-baking time is preferably 600 seconds, and more preferably 300 seconds. The lower limit of the average thickness of the resist film is preferably 10 nm, and more preferably 20 nm. The upper limit of the average thickness is preferably 300 nm, and more preferably 150 nm.

  As shown in FIG. 2, when the developer is an alkali developer, the latent image on the resist film 12 when the amount of energy applied to the resist film exceeds a threshold value Ea (hereinafter also referred to as “latent image formation energy”). The portion where the latent image is formed begins to dissolve in the developer. When the amount of energy further increases and exceeds a threshold Et (hereinafter also referred to as “required energy amount”), the portion where the latent image is formed is completely dissolved and removed in the developer.

  The resist pattern forming method may further include a step of forming an organic underlayer film on the surface side of the substrate on which the resist film is formed before the resist film forming step. Examples of the organic underlayer film include an organic film formed using a resist underlayer film composition, a carbon film formed by a conventionally known CVD (Chemical Vapor Deposition) method, and the like.

  Further, a step of forming a silicon-containing film on the surface of the organic underlayer film on which the resist film is formed may be further provided between the organic underlayer film forming step and the resist film forming step. The silicon-containing film is formed using, for example, a polysiloxane composition containing polysiloxane and a solvent. The polysiloxane is not particularly limited as long as it is a polymer having a siloxane bond, but a hydrolysis condensate of a compound containing a silane compound having a hydrolyzable group is preferable.

  After the resist film forming step, a step of forming a protective film on the surface of the resist film opposite to the substrate may be provided. By forming a protective film, the immersion liquid in immersion exposure is prevented from coming into direct contact with the resist film, and the resist is formed by penetration of the immersion liquid into the resist film and elution of the resist film components into the immersion liquid. Deterioration of performance can be suppressed, and lens contamination of the exposure apparatus due to components eluted into the immersion liquid can be prevented. In addition, evaporation of outgas from the resist film can be reduced during exposure using radiation such as EUV or electron beam, so that contamination of the exposure apparatus can be prevented. The protective film can be formed using, for example, a composition containing a polymer having a fluorine atom and / or a silicon atom and a solvent.

<Exposure process (1)>
Next, as shown in FIG. 1B, in the exposure step (1) (S103), the resist film 12 is exposed by irradiation with exposure light (I). The exposure light (I) includes radiation having a wavelength (I) that can be absorbed by the [B] component to generate an acid. Upon exposure to exposure light (I), an acid is generated from the [B] component in the resist film 12, and the sensitizer is a compound represented by the above formula (1 ′) from the [C] compound by the action of this acid. Produces. In the resist film 12, both generation of acid from the [B] component and generation of sensitizer from the [C] compound occur. Due to the action of the acid generated from the [B] component, polarity conversion, crosslinking, decomposition reaction and the like occur in the [A] component, and as a result, the solubility of the [A] component in the developer changes. In order to form a resist pattern by development, it is necessary to generate a certain amount of acid from the [B] component. It is preferable that the exposure light (I) does not substantially contain radiation having a wavelength (II) in the exposure light (II) described later. Since the exposure light (I) does not substantially contain radiation having the wavelength (II), the nano edge roughness performance of the resist pattern can be further improved.

  The exposure step (1) is performed in a vacuum or an inert atmosphere, for example. The exposure light (I) is emitted from the exposure light source 21 so as to irradiate the resist film 12 from above. Here, the exposure light (I) is applied to one surface in the resist film 12. As shown in FIG. 1, the exposure light (I) is irradiated, for example, on the entire surface of the resist film 12. However, the exposure light (I) may be applied only to a part of the region, such as a pattern, to the entire resist film 12. The exposure light (I) is an electromagnetic wave such as visible light, UV (ultraviolet light), DUV (deep ultraviolet light), EUV, or X-ray. Further, the exposure light (I) may be an electron beam or an ion beam. Of these, EUV and electron beam are preferable as the exposure light (I).

  As shown in FIG. 2, in the exposure step (1) (S103), the exposure light (I) dose Ef is a dose that does not exceed the latent image formation energy amount Ea. That is, in the exposure step (1) (S103), less acid than the amount necessary for forming a resist pattern at the time of development is generated from the [B] component. For this reason, at the stage of performing the exposure step (1) (S103), the resist film 12 is not dissolved in the developer, and a resist pattern is not formed.

<Holding process>
After the exposure step (1), as shown in FIG. 1C, a holding step (S105) may include a step of holding the state of the resist layer 12. Specifically, until the exposure process (2) (S107) described later is executed, the environment is controlled without performing pre-baking, and the exposure light (I) is irradiated in the exposure process (1) (S103). A reduction in the amount of acid generated from the [B] component in the resist film 12 and the amount of sensitizer generated from the [C] compound is suppressed.

  For example, the environment around the resist film 12 is an atmosphere in which the decrease in the amount of acid and sensitizer generated in the exposure step (1) can be controlled. The atmosphere that can control the decrease in the amount of acid and sensitizer may be an inert gas atmosphere or a vacuum atmosphere that does not contain a basic substance. In addition, a protective film that blocks basic substances and / or oxygen may be provided. In the case of an inert gas atmosphere, for example, nitrogen gas, helium gas, argon gas or the like is used as the inert gas, and can be used under reduced pressure or increased pressure. In the case of a vacuum atmosphere, it is sufficient that the periphery of the resist film 12 is under vacuum. Preferably, the periphery of the resist film 12 is set to a vacuum of 1 Pa or less. In the environment of an inert gas atmosphere or a vacuum atmosphere, a decrease in the amount of sensitizer generated in the resist film 12 is suppressed.

  The environment around the resist film 12 may be an atmosphere or a liquid that can increase the amount of acid and / or sensitizer in the resist film 12. An active gas atmosphere is used as an atmosphere that can increase the amount of acid and / or sensitizer. As the active gas atmosphere, for example, a reactive gas for shifting the absorption wavelength is used. As an active liquid that can increase the amount of acid and sensitizer, for example, a reactive liquid for shifting the absorption wavelength is used. The sensitizer generated in the resist film 12 reacts with the active gas or the active liquid, and is converted into the active substance α or the stable substance α1 in the exposure step (2) (S107) described later. The active substance α or the stable substance α1 can function as a sensitizer similarly to the sensitizer produced from the [C] compound. The active substance α is, for example, an aromatic compound radical or an iodine compound radical, and the stable substance α1 is, for example, an aromatic compound or an iodine compound. When the active liquid is used, the active liquid may be removed from the resist film 12 before the exposure process (2) (S107) is performed, or the exposure process (2) without removing the active liquid. (S107) may be executed.

  Further, as a method for controlling the environment, a method for controlling the temperature of the resist film 12 may be used. Since the amount of acid and / or sensitizer decreases when the temperature of the resist film 12 exceeds a certain threshold temperature, the acid and / or increase of the resist film 12 is maintained by keeping the temperature of the resist layer 12 below the threshold temperature. A decrease in the amount of the sensation body can be suppressed. For example, after the exposure step (1) (S103), the temperature of the resist film 12 is lowered below the threshold temperature by performing a rapid cooling process in the holding step (S105). The threshold temperature is, for example, 30 ° C. Alternatively, the exposure step (1) (S103) may be performed at a predetermined temperature or lower, and the temperature of the resist film 12 may be maintained at a threshold temperature or lower in the holding step (S105).

  In addition, if the resist film 12 is irradiated with unexpected radiation before the exposure step (2) (S107) is performed, the amount of acid and / or sensitizer may decrease. For this reason, in the holding step (S105), the resist film 12 is positioned in an environment that is not irradiated with radiation.

  Further, since the amount of acid and / or sensitizer decreases with time, the elapsed time between the exposure step (1) (S103) and the exposure step (2) (S107) described later is controlled. Thus, a decrease in the amount of acid and / or sensitizer in the resist film 12 can also be suppressed. The time from the exposure step (1) to the later-described exposure step (2) is preferably within 60 minutes. Note that the control of temperature, illuminance, or time may be performed simultaneously with the control of the environment around the resist film 12.

<Exposure process (2)>
After the exposure step (1) (S103) or the holding step (S105), as shown in FIG. 1 (d), the exposure step (2) (S107) is executed. In the exposure step (2), a pattern latent image is formed on the resist film 12 exposed with the exposure light (I) by irradiation with exposure light (II) containing radiation having a wavelength (II) longer than the wavelength (I). . The exposure light (II) acts on the sensitizer, the active substance α and / or the stable substance α1 generated from the [C] compound, and contains radiation (II) that can generate an acid from the [B] component. It is. In the region of the resist film 12 irradiated with the exposure light (II), the sensitizer produced from the [C] compound and the production of the sensitizer from the [C] compound by the action of the active substance α / stable substance α1, And generation of an acid (or an acid having a structure different from that of the acid) from the component [B]. The exposure light (II) is a radiation that generates an acid from the [B] component by the action of the sensitizer and the active substance α / stabilizing substance α1, and also generates an acid from the [B] component in the resist film 12. There may be. In this case, at the site of the resist film 12 irradiated with the exposure light (II), an acid (or an acid having a structure different from this acid) is generated from the component [B], and the sensitizer and the active substance α / stable A sensitizer is generated from the [C] compound by the action of the substance α1, and an acid (or an acid having a structure different from that of the acid) is generated from the [B] component. As shown in FIG. 2, in the exposure step (2) (S107), the exposure light (II) irradiation amount Ep is an irradiation amount not exceeding the latent image forming energy amount Ea, and the exposure light (II). The sum total of the irradiation amount Ep and the irradiation amount Ef of the exposure light (I) exceeds the required energy amount Et. In other words, the amount of acid generated from the component [B] by the action of the sensitizer and the active substance α / stable substance α1 in the exposure step (2) (S107) is the same as that in the exposure step (1) (S103). The amount of acid produced from the component [B] in the exposure step (1) (S103) is smaller than the amount necessary for forming a resist pattern during development, except when no acid is produced from the component. In step (2) (S107), the total amount of the acid obtained from the component [B] exceeds the amount necessary for forming a resist pattern during development.

  The exposure light (II) is emitted from the exposure light source (2) 22 so as to irradiate the resist film 12 from above. The exposure light source (2) 22 may be the same as the exposure light source (1) 21 that emits the exposure light (I), or may be different from the exposure light source (1) 21. Here, the exposure light (II) is irradiated in a pattern shape in the region of the resist film 12 irradiated with the exposure light (I). The exposure light (II) can be selected according to the resolution of the pattern to be formed. For example, the exposure light (II) may be an electromagnetic wave such as UV, DUV, EUV, or X-ray, and may be an electron beam or an ion beam. The exposure step (2) is performed in, for example, a vacuum atmosphere, an active gas atmosphere, or an inert atmosphere. As described above, the resist film 12 is exposed to the exposure part (A) 121 irradiated only with the exposure light (I), and the exposure part (B) irradiated with both the exposure light (I) and the exposure light (II). 122 (see FIG. 1).

<Development process>
After the exposure step (2), a development step (S110) is performed as shown in FIG. In the development step, the resist film 12 is developed. The development of the resist film 12 is performed, for example, by performing post-exposure baking and then placing the substrate 11 in a developer tank. In the present embodiment, the irradiation amount Ef received by the exposed portion (A) 121 of the resist film 12 does not exceed the latent image forming energy amount Ea. Since the amount of acid generated from the component [B] in the exposed portion (A) 121 is less than the amount necessary for forming the resist pattern, the exposed portion (A) 121 is not dissolved in the developer. On the other hand, the energy amount Es (that is, Ef + Ep) received by the exposed portion (B) 122 of the resist film 12 exceeds the required energy amount Et. In the exposed portion (A) 121, the sum of the amount of acid generated from the component [B] in the exposure step (1) and the amount of acid generated by the action of a sensitizer or the like is necessary for forming a resist pattern. Since the amount is exceeded, the exposed portion (B) 122 is dissolved in the developer. Thus, a predetermined resist pattern is formed on the substrate 11.

  The developer used in the development process may be an alkali developer or an organic solvent developer. By using an alkaline developer, a positive resist pattern can be obtained. By using an organic solvent developer, a negative resist pattern can be obtained.

  Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine. , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4 .3.0] -5 aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved. In these, a TMAH aqueous solution is preferable and a 2.38 mass% TMAH aqueous solution is more preferable.

  Examples of the organic solvent developer include organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, and liquids containing organic solvents. Examples of the organic solvent include one or more of the solvents exemplified as the [E] solvent of the above-described radiation-sensitive resin composition. Among these, ester solvents and ketone solvents are preferable. As the ester solvent, an acetate solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. The lower limit of the content of the organic solvent in the organic solvent developer is preferably 80% by mass, more preferably 90% by mass, further preferably 95% by mass, and particularly preferably 99% by mass. Examples of components other than the organic solvent in the organic solvent developer include water and silicone oil.

  These developers may be used alone or in combination of two or more. In general, after development, the substrate is washed with water or the like and dried.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Each physical property was measured by the following method.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Mw and Mn of the polymer were measured using a Tosoh GPC column (2 G2000HXL, 1 G3000HXL and 1 G4000HXL), flow rate 1.0 mL / min, elution solvent tetrahydrofuran, sample concentration 1.0 mass%, sample injection Measurement was performed by GPC using a monodisperse polystyrene as a standard using a differential refractometer as a detector under analysis conditions of an amount of 100 μL and a column temperature of 40 ° C.

[ 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.

<Synthesis of [A] Component>
The monomers used for the synthesis of the polymer of component [A] are shown below.

[Synthesis Example 1]
After dissolving 55 g (50 mol%) of the compound (M-1), 45 g (50 mol%) of the compound (M-2) and 3 g of AIBN (3.6 mol% based on the total amount of the compounds) in 300 g of methyl ethyl ketone. Under a nitrogen atmosphere, the reaction temperature was maintained at 78 ° C., and polymerization was performed for 6 hours. After completion of the polymerization reaction, the polymerization 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). 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 ratios of structural units derived from (M-1) and (M-2) were 52 mol% and 48 mol%, respectively.

[Synthesis Example 2]
In a nitrogen atmosphere, 55 g (42 mol%) of the above compound (M-3), 45 g (58 mol%) of the above compound (M-1), 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 completion of the polymerization reaction, the polymerization reaction solution was dropped into 1,000 g of n-hexane to solidify and purify the polymer. Next, 150 g of propylene glycol monomethyl ether was added to the polymer, 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). The polymer (A-2) had Mw of 6,000 and Mw / Mn of 1.90. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (M-1) and hydroxystyrene were 50 mol% and 50 mol%, respectively.

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

[Synthesis of [C] Compound]
[Synthesis Example 5]
A 300 mL three-necked flask was charged with 100 mL of methylene chloride, 10.0 g (50.1 mmol) of phenothiazine (a compound represented by the following formula (PTZ)) and 6.13 g (50.2 mmol) of dimethylaminopyridine. A mixed solution of 10.9 g (50 mmol) of ditert-butyl dicarbonate and 20 mL of methylene chloride was added dropwise over 30 minutes under a nitrogen stream and under ice cooling, and the mixture was stirred at room temperature for 2 hours after completion of the addition. Next, the produced salt is filtered off from the reaction solution, and the obtained organic layer is washed with ultrapure water three times to remove the water-soluble portion such as the salt and dimethylaminopyridine. Was collected and concentrated under reduced pressure. The obtained concentrate was purified by silica gel column chromatography using ethyl acetate / hexane (1/1 (mass ratio)) to obtain a compound represented by the following formula (PT-PTZ) in a yield of 60%. Obtained.

[Synthesis Examples 6 and 7]
A compound represented by the following formula (PT-MeOPTZ) and a compound represented by the following formula (PT-CF ₃ PTZ) were synthesized in the same manner as in Synthesis Example 5 except that the raw material compound was changed from phenothiazine. .

The measurement results of ¹ H-NMR spectrum and GC-Mass analysis of the synthesized compound (PT-PTZ), compound (PT-MeOPTZ) and compound (PT-CF ₃ PTZ) are shown below.

Compound (PT-PTZ): ¹ H-NMR (CDCl ₃ , δ: ppm); 7.70-7.00 (8H, Ar), 1.38 (9H, tert-Bu), GC-Mass; m / z = 299.10.

Compound (PT-MeOPTZ): ¹ H-NMR (CDCl ₃ , δ: ppm); 7.70-6.90 (7H, Ar), 3.83 (3H, —OMe), 1.38 (9H, tert -Bu), GC-Mass; m / z = 329.10.

Compound (PT-CF ₃ PTZ): ¹ H-NMR (CDCl ₃ , δ: ppm); 7.70-7.00 (7H, Ar), 1.38 (9H, tert-Bu), GC-Mass; m / z = 367.10.

[Synthesis Example 8]
A 300 mL three-necked flask is charged with 100 mL of methylene chloride, 10.0 g (50.1 mmol) of phenothiazine and 6.13 g (50.2 mmol) of dimethylaminopyridine, and 7.17 mL (50 mmol) of benzyl chloroformate and methylene chloride from the dropping funnel. The mixed solution with 20 mL was added dropwise over 30 minutes under a nitrogen stream and under ice cooling. After completion of the addition, the mixture was stirred at room temperature for 2 hours. Next, the salt and the reaction solution are separated by filtration, the reaction solution is washed three times with ultrapure water, the salt and the water-soluble part such as dimethylaminopyridine are removed, the organic layer is recovered, and the pressure is reduced. Concentrated. The obtained concentrate was purified by silica gel column chromatography using ethyl acetate / hexane (1/1 (volume ratio)) to obtain a compound represented by the following formula (PZ-PTZ) in a yield of 70%. Obtained.

[Synthesis Examples 9 and 10]
A compound represented by the following formula (PZ-MeOPTZ) and a compound represented by the following formula (PZ-CF ₃ PTZ) were synthesized in the same manner as in Synthesis Example 8 except that the raw material compound was changed from phenothiazine. .

The measurement results of ¹ H-NMR spectrum and GC-Mass analysis of the synthesized compound (PZ-PTZ), compound (PZ-MeOPTZ), and compound (PZ-CF ₃ PTZ) are shown below.

Compound (PZ-PTZ): ¹ H-NMR (CDCl ₃ , δ: ppm); 7.70-7.00 (13H, Ar), 5.08 (2H, —CH ₂ —), GC-Mass; m /Z=333.10

Compound (PZ-MeOPTZ): ¹ H-NMR (CDCl ₃ , δ: ppm); 7.70-6.90 (13H, Ar), 5.09 (2H, —CH ₂ —), 3.83 (3H) , -OMe), GC-Mass; m / z = 363.10.

Compound (PZ—CF ₃ PTZ): ¹ H-NMR (CDCl ₃ , δ: ppm); 7.70-7.00 (7H, Ar), 5.09 (2H, —CH ₂ —), GC-Mass M / z = 367.10.

<Preparation of radiation-sensitive resin composition>
Each component other than [A] component used for preparation of a radiation sensitive resin composition is shown below.

[[B] component]
B-1: Triphenylsulfonium perfluoro-n-octanesulfonate (compound represented by the following formula (B-1))
B-2: Diphenyliodonium perfluoro-n-octanesulfonate (compound represented by the following formula (B-2))

[[C] Compound]
Compound (PT-PTZ), Compound (PT-MeOPTZ), Compound (PT-CF ₃ PTZ), Compound (PZ-PTZ), Compound (PZ-MeOPTZ) and Compound (PZ-CF ₃ PTZ) synthesized above

[[C ′] Compound]
Phenothiazine (compound represented by the following formula (PTZ)) and di (4-methoxyphenyl) ketone (compound represented by the following formula (MeOBzP))

[[D] acid diffusion controller]
D-1: Nt-amyloxycarbonyl-4-hydroxypiperidine (compound represented by the following formula (D-1))

[[E] solvent]
E-1: Propylene glycol monomethyl ether acetate E-2: γ-butyrolactone

[Example 1]
[A] component (A-1) 100 parts by mass, [B] component (B-1) 20 parts by mass, [C] compound PT-PTZ 5 parts by mass, [D] acid diffusion controller 2 parts by weight as (D-1) and 4,300 parts by weight as (E-1) solvent and 1,900 parts by weight as (E-2) solvent, and the resulting mixture was mixed with a pore size of 0. The mixture was filtered through a 20 μm membrane filter to prepare a radiation sensitive resin composition (S-1). The solid content concentration of the radiation sensitive resin composition (S-1) was 2.0 mass%.

[Examples 2 to 14 and Comparative Examples 1 to 3]
Each radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that the components having the types and contents shown in Table 2 were used. Table 2 shows the solid content concentration (% by mass) of each radiation-sensitive resin composition.

<Formation of resist pattern>
[Example 1]
After spin-coating the prepared radiation sensitive resin composition (S-1) on a silicon wafer in “Clean Track ACT-8” of Tokyo Electron, PB was performed under conditions of 110 ° C. and 60 seconds, A resist film having an average thickness of 50 nm was formed. Subsequently, patterning was performed by irradiating an electron beam using a simple electron beam drawing apparatus (“HL800D” manufactured by Hitachi, Ltd., output: 50 KeV, current density: 5.0 ampere / cm ² ). After the electron beam irradiation, the following operation (a) or (b) was performed.

(A) Immediately after the electron beam irradiation, PEB was performed in the clean track ACT-8 under the conditions of 100 ° C. and 60 seconds, and then a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution was added. Used, developed by the paddle method at 23 ° C. for 1 minute, washed with pure water, and dried to form a positive resist pattern.

(B) After irradiation with the electron beam, the entire surface was exposed in the air for 10 minutes using a black light (wavelength: 320 nm) manufactured by Toshiba Corporation so that the irradiation amount was 1 mW / h. Then, immediately after PEB was performed in the clean track ACT-8 at 100 ° C. for 60 seconds, a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution was used for 1 minute at 23 ° C. Developed by paddle method, washed with pure water and dried to form a positive resist pattern

[Examples 2 to 13 and Comparative Examples 1 to 3]
Each resist pattern was formed in the same manner as in Example 1 except that the radiation-sensitive resin composition shown in Table 3 below was used.

<Evaluation>
The sensitivity and nanoedge roughness performance of the radiation sensitive resin composition were evaluated by measuring the formed positive resist pattern according to the following method. The evaluation results are shown in Table 3.

[sensitivity]
Optimum exposure amount is used to form a line-and-space pattern (1L1S) having a line portion of 150 nm and a space portion having an interval of 150 nm formed by adjacent line portions having a line width of 150 nm with a one-to-one line width. This optimum exposure amount was defined as sensitivity (μC / cm ² ). When the sensitivity was 35 μC / cm ² or less, it was evaluated as “A (good)”, and when it exceeded 35 μC / cm ² , it was evaluated as “B (bad)”.

[Nano edge roughness (LER) performance]
The line pattern of the line and space pattern (1L1S) was observed using a high-resolution FEB length measuring device (“S-9220” from Hitachi, Ltd.). Arbitrary 20 points in the substrate were observed, and the observed shape was uneven along the lateral surface 2a of the line part 2 of the resist film formed on the silicon wafer 1, as shown in FIGS. The difference “ΔCD” between the line width at the most remarkable point and the design line width of 150 nm was measured, and the average value of this ΔCD was defined as nano edge roughness performance (nm). When the nano edge roughness performance is 15.0 nm or less, “AA (very good)”, when it exceeds 15.0 nm and 16.5 nm or less, “A (good)”, and when it exceeds 16.5 nm It was evaluated as “B (defect)”. In addition, the unevenness | corrugation shown in FIG.3 and FIG.4 is exaggerated rather than actually.

  As can be seen from the results in Table 3, the radiation-sensitive resin compositions of the examples are superior in both sensitivity and nanoedge roughness performance as compared with the radiation-sensitive resin compositions of the comparative examples. According to the radiation sensitive resin composition of the example, a resist pattern with a small nano edge roughness can be formed by the process (a) in which the black light irradiation is not performed after PEB, but the process of performing the black light irradiation after PEB ( By performing b), the sensitivity can be improved, and the nano edge roughness performance can be further improved. In general, it is known that the electron beam exposure shows the same tendency as in the case of EUV exposure. Therefore, according to the radiation-sensitive resin composition of the example, in the case of EUV exposure. Is presumed to be excellent in sensitivity and nanoedge roughness performance.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, a resist pattern that can exhibit high sensitivity and has a small nano edge roughness can be formed. Therefore, these can be suitably used for manufacturing semiconductor devices that are expected to be further miniaturized in the future.

DESCRIPTION OF SYMBOLS 1 Base material 2 Resist pattern 2a Side surface 11 of resist pattern 11 Substrate 12 Resist film 21 Exposure light source (1)
22 Exposure light source (2)
121 Exposure part (A)
122 Exposure part (B)

Claims (11)

A first component whose solubility in a developer is changed by the action of an acid;
A radiation-sensitive resin composition comprising a second component that generates an acid by the action of radiation, and a compound represented by the following formula (1).

(In Formula (1), Ar ¹ is an (m + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. M is an integer of 0 to 11. Ar ² is 6 to 20 carbon atoms. N is an integer of 0 to 11. R ¹ and R ² each independently represent a hydroxy group, a sulfanyl group, an amino group, or a carbon number of 1 to A monovalent organic group of 20. When m is 2 or more, a plurality of R ^{1 s} may be the same or different, and two or more of the plurality of R ¹ are combined with each other and bonded together. And may form a ring structure having 3 to 20 ring members, and when n is 2 or more, the plurality of R ² may be the same or different, and two or more of the plurality of R ² may be combined with each other. And a carbon chain to which these are bonded may form a ring structure having 3 to 20 ring members. If 1 or more and n is 10 or less, and the carbon atoms are combined together to form one aromatic ring of the aromatic hydrocarbon group ^{R 1} and Ar ^2, -O ^{where R 1} has -, - S -, - A ring may be formed through NR′- or an organic group having 1 to 20 carbon atoms, R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is It is a group dissociated by the action of an acid.)   The radiation-sensitive resin composition according to claim 1, wherein the first component is a polymer having an acid dissociable group.   The radiation-sensitive resin composition according to claim 1 or 2, wherein the second component is a radiation-sensitive acid generator.   The radiation-sensitive resin composition according to claim 1 or 2, wherein the second component is a polymer having a group capable of generating an acid. The radiation sensitive resin composition according to any one of claims 1 to 4, wherein the compound is represented by the following formula (1-1).

(In the formula (1-1), R ¹ , R ² , R ³ , m and n are as defined in the above formula (1). X is O, S or NR ′. R ′ is hydrogen. It is an atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and when R ¹ is plural, plural R ¹ may be the same or different, and when R ² is plural, plural R ² are the same. And a and b are each independently an integer of 0 to 3.)   The radiation sensitive resin composition according to any one of claims 1 to 5, wherein the compound has a phenothiazine skeleton. The radiation sensitive resin composition according to any one of claims 1 to 6, wherein R ³ in the formula (1) is represented by the following formula (2).

(In formula (2), R ⁴ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁵ and R ⁶ are each independently a hydrogen atom or a monovalent hydrocarbon having 1 to 20 carbon atoms. It is a hydrocarbon group, or represents an alicyclic structure having 3 to 20 ring members composed of these groups together with the carbon atoms to which they are bonded, and * represents a nitrogen atom in the above formula (1). Indicates the binding site.) A step of forming a resist film on a substrate using the radiation-sensitive resin composition according to any one of claims 1 to 7,
A first exposure step of pattern-exposing the resist film with first exposure light containing radiation of a first wavelength absorbed by the second component;
A second exposure step of exposing the resist film pattern-exposed with the first exposure light with a second exposure light containing radiation having a second wavelength longer than the first wavelength;
And a step of developing the resist film exposed with the second exposure light.   The resist pattern forming method according to claim 8, wherein in the second exposure step, acid is not substantially generated from the second component in a region where the first exposure light is not irradiated in the first exposure step.   The sensitizer is produced from the compound represented by the formula (1) by the action of the acid generated from the second component in the first exposure step. Resist pattern forming method. 11. The resist pattern formation according to claim 10, wherein an acid is generated from the second component by the action of the sensitizer in the exposed portion exposed by the first exposure light in the second exposure step. Method.

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