JP4725421B2 - 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 for forming a photoresist film suitable for a resist pattern forming method including an immersion exposure step of irradiating radiation through an immersion exposure liquid. More specifically, during the immersion exposure process, when the substrate with the photoresist film is placed in an immersion exposure liquid such as water, the amount of the substance eluted from the photoresist film can be reduced. The present invention relates to a radiation-sensitive resin composition and a resist pattern forming method capable of forming a photoresist film having a good cross-sectional shape of a resist pattern and excellent resolution and depth of focus.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, a lithography technique capable of microfabrication at a level of 0.10 μm or less is required. However, in the conventional lithography process, near ultraviolet rays such as i rays are generally used as radiation, and it is said that fine processing at the subquarter micron level is extremely difficult with this near ultraviolet rays. Therefore, in order to enable fine processing at a level of 0.20 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, X-rays, and electron beams. An ArF excimer laser (wavelength: 193 nm) has attracted attention.
As a resist suitable for irradiation with such an excimer laser, a component having an acid-dissociable group and a component that generates acid upon irradiation with radiation (hereinafter also referred to as “exposure”) (hereinafter referred to as “acid generator”). )) And a resist utilizing the chemical amplification effect (hereinafter referred to as “chemically amplified resist”) have been proposed. As the chemically amplified resist, for example, a resist containing a resin having a tert-butyl ester group of carboxylic acid or a tert-butyl carbonate group of phenol and an acid generator has been proposed. In this resist, a tert-butyl ester group or tert-butyl carbonate group present in the resin is dissociated by the action of an acid generated by exposure, and the resin has an acidic group composed of a carboxyl group or a phenolic hydroxyl group. As a result, it utilizes the phenomenon that the exposed region of the resist becomes readily soluble in an alkaline developer.

  In such a lithography process, further fine pattern formation (for example, a fine resist pattern having a line width of about 90 nm) is required. In order to achieve such a pattern formation finer than 90 nm, it is conceivable to shorten the light source wavelength of the exposure apparatus and increase the numerical aperture (NA) of the lens as described above. However, a new expensive exposure apparatus is required to shorten the light source wavelength. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

  Recently, a liquid immersion lithography (liquid immersion lithography) method has been reported as a lithography technique that can solve such problems. In this method, at the time of exposure, a liquid refractive index medium (immersion liquid) such as pure water or a fluorine-based inert liquid having a predetermined thickness is interposed on at least the photoresist film between the lens and the photoresist film on the substrate. It is to let you. In this method, a light source having the same exposure wavelength can be used by replacing the exposure optical path space, which has conventionally been an inert gas such as air or nitrogen, with a liquid having a higher refractive index (n), such as pure water. Similar to the case of using a light source with a shorter wavelength or the case of using a high NA lens, high resolution is achieved and there is no reduction in the depth of focus. If such immersion exposure is used, it is possible to realize the formation of a resist pattern that is low in cost, excellent in high resolution, and excellent in depth of focus, using a lens mounted on an existing apparatus. It is attracting a lot of attention.

However, in the above immersion exposure process, the photoresist film is brought into direct contact with a high refractive index liquid (immersion liquid) such as water during exposure, so that the acid generator and the like are eluted from the photoresist film before exposure. There is a possibility. If the amount of the eluate is large, the immersion liquid contains impurities, causing damage to the lens, a predetermined pattern shape cannot be obtained, and sufficient resolution cannot be obtained.
Therefore, it has been eagerly desired to further reduce the amount of elution of the acid generator and the like into the immersion liquid in the resist used in the immersion exposure apparatus.
As resins for forming a resist film used in an immersion exposure apparatus, for example, resins described in Patent Document 1 and Patent Document 2 have been proposed. However, even with resists using these resins, the depth of focus is not always sufficient.

International Publication WO 2004-068242 JP 2005-173474 A

  The object of the present invention is to reduce the amount of a substance eluted from a photoresist film when the substrate with a photoresist film is placed in an immersion exposure liquid such as water during the immersion exposure process. The present invention provides a radiation-sensitive resin composition capable of forming a photoresist film having a good cross-sectional shape of the obtained resist pattern and excellent in resolution and depth of focus, and a resist pattern forming method using the composition. There is.

As means for achieving the above object, the invention of claim 1 is a photoresist film forming step of applying a radiation sensitive resin composition on a substrate to form a photoresist film,
Performing a pre-application bake (PAB) on the photoresist coating;
A step of performing immersion exposure in which a liquid for immersion exposure having a refractive index higher than that of air at a wavelength of 193 nm is interposed between the lens and the photoresist film, and the photoresist film is irradiated with radiation;
Performing a post-exposure bake on the photoresist coating;
A development step of removing an exposed portion of the photoresist film with a developer, and a resist pattern forming method comprising:
The radiation-sensitive resin composition used for forming the photoresist coating contains a resin having a glass transition temperature of 70 to 150 ° C., a radiation-sensitive acid generator, a nitrogen-containing compound, and a solvent.
Resist pattern, characterized in that the have line pre application bake at a temperature above the glass transition temperature of the resin, and the temperature difference between the glass transition temperature of said resin of the pre-application bake and 5 to 50 ° C. It is a forming method.

  The invention according to claim 2 is the resist pattern forming method according to claim 1, wherein the glass transition temperature of the resin is 80 to 150 ° C.

  The invention according to claim 3 is the method for forming a resist pattern according to claim 1 or 2, wherein the resin includes a repeating unit having a structure expressing alkali solubility by the action of an acid and a repeating unit having a lactone structure. is there.

  The invention according to claim 4 is the resist pattern according to any one of claims 1 to 3, wherein in the step of performing the immersion exposure, the exposure is performed in a state in which an immersion exposure liquid is disposed on the surface of the photoresist film. It is a forming method.

The invention of claim 5 is a photoresist film forming step of applying a radiation sensitive resin composition on a substrate and forming a photoresist film;
Performing a pre-application bake (PAB) on the photoresist coating;
A step of performing immersion exposure in which a liquid for immersion exposure having a refractive index higher than that of air at a wavelength of 193 nm is interposed between the lens and the photoresist film, and the photoresist film is irradiated with radiation;
Performing a post-exposure bake on the photoresist coating;
A development step of removing an exposed portion of the photoresist film with a developer, a resist pattern forming method, wherein the radiation-sensitive resin composition used for forming the photoresist film,
A resin having a glass transition temperature of 70 to 150 ° C., a radiation-sensitive acid generator, a nitrogen-containing compound, and a solvent;
Wherein the glass transition temperature of the resin is, the Ri der temperature below when performing pre-application bake, and the temperature difference between the glass transition temperature of said resin of the pre-application bake is 5 to 50 ° C. It is a radiation sensitive resin composition.

According to the resist pattern forming method of the present invention, it is possible to obtain a resist pattern having excellent resolution and depth of focus and having a good cross-sectional shape.
Further, according to the present invention, in the immersion exposure process using the substrate with the photoresist film obtained by forming the photoresist film made of the composition on the surface of a silicon substrate or the like, the substrate with the photoresist film Can be reduced in the amount of the substance eluted from the photoresist film when placed in an immersion exposure liquid such as water, the resist pattern has a good cross-sectional shape, and resolution and depth of focus are also improved. Excellent.

  Hereinafter, the present invention will be described in detail. In the present specification, “(meth) acryl” means acryl and methacryl, and “(meth) acrylate” means acrylate and methacrylate.

1. Radiation-sensitive resin composition The radiation-sensitive resin composition of the present invention (hereinafter referred to as “the composition of the present invention”) contains a resin, a radiation-sensitive acid generator, a nitrogen-containing compound, and a solvent. In addition, the glass transition temperature of the resin is equal to or lower than a pre-application baking (PAB) temperature when forming a resist pattern.

1-1. Resin (hereinafter, also referred to as "resin (A)".) According to the resin present invention the glass transition temperature (Tg) of, 70 to 150 ° C. der is, more preferably eighty to one hundred and forty-five ° C., more preferably 90 to 140 ° C, particularly preferably 95 to 130 ° C, most preferably 95 to 120 ° C. In addition, Tg of this resin can be measured by scanning calorimetry (Differential Scanning Calorimeter). The Tg can be controlled by selection of the main chain skeleton of the repeating unit, bulkiness and flexibility of the pendant portion, copolymer composition, and molecular weight.
Moreover, the temperature of the said pre-application baking (PAB) at the time of forming a resist pattern is 70-150 degreeC normally, Preferably it is 75-150 degreeC, More preferably, it is 80-150 degreeC.
Furthermore, a glass transition temperature of the resin (A), the difference between the pre-application bake (PAB) temperature is 5 to 50 ° C., particularly preferably from 10 to 50 ° C..
Thus, the density of the photoresist film can be increased when the glass transition temperature of the resin [A] is equal to or lower than the pre-application baking (PAB) temperature for forming the resist pattern, and the composition of the present invention. Reducing the amount of a substance eluted from the photoresist film when the substrate with the photoresist film comprising the photoresist film is placed in an immersion exposure liquid such as water during the immersion exposure process. it can. Furthermore, a resist pattern having a good cross-sectional shape can be obtained, and resolution and depth of focus can be improved.

  The resin [A] contains a repeating unit having a structure that expresses alkali solubility by the action of an acid (hereinafter referred to as “repeating unit [1]”) as an essential unit. In addition, in any case of two or more kinds, it is an alkali-insoluble or alkali-insoluble resin that becomes alkali-soluble by the action of an acid. “Alkali-insoluble or hardly soluble in alkali” means that under the alkali development conditions employed when a resist pattern is formed from a photoresist film comprising a radiation-sensitive resin composition containing the resin [A]. When a film made only of the resin [A] is developed instead of the resist film, it means that 50% or more of the initial film thickness of the film remains after development.

  The repeating unit [1] in the present invention is particularly preferably a unit represented by the following general formula (1) (hereinafter referred to as “repeating unit (1a)”).

〔式中、Ｒ^１は、水素原子、メチル基又はトリフルオロメチル基を表し、Ｒ^２は、炭素数１〜４の直鎖状又は分岐状のアルキル基を表す。〕

[Wherein, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group, and R ² represents a linear or branched alkyl group having 1 to 4 carbon atoms. ]

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ² include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1 -A methylpropyl group, a tert-butyl group, etc. can be mentioned. Among these alkyl groups, a methyl group, an ethyl group, an n-propyl group, and an isopropyl group are preferable.

Here, preferred examples of the repeating unit (1a) include (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, and (meth) acrylic acid 1-propyl. Examples include -1-cyclopentyl ester and (meth) acrylic acid 1-isopropyl-1-cyclopentyl ester.
Among these, (meth) acrylic acid 1-methyl-1-cyclopentyl ester and (meth) acrylic acid 1-ethyl-1-cyclopentyl ester are preferable.

Resin [A] in this invention may contain only 1 type of the said repeating unit (1a), and may contain 2 or more types.
Further, the resin [A] contains, as the repeating unit [1], a unit represented by the following general formula (2) other than the repeating unit (1a) (hereinafter referred to as “repeating unit (1b)”). It may be.

In the general formula (2), R ³ represents a hydrogen atom, a methyl group, or a trifluoromethyl group.
In the general formula (2), each R ⁴ is independently of each other a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a straight chain having 1 to 4 carbon atoms or It is a branched alkyl group. More preferable R ⁴ satisfies the following condition (i) or (ii).
(I) At least one R ⁴ is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof.
(Ii) Two R ^4's are combined to have a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative structure thereof, and the remaining R ⁴ is a monovalent fat having 4 to 20 carbon atoms. It is a cyclic hydrocarbon group or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms.

In the general formula (2), a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms as R ⁴ and a divalent hydrocarbon having 4 to 20 carbon atoms formed by combining two R ⁴ groups. The alicyclic hydrocarbon group consists of alicyclic rings derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, etc. Group and a group consisting of these alicyclic rings, a hydrogen atom is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, Examples thereof include a group substituted with one or more linear or branched or cyclic alkyl groups having 1 to 4 carbon atoms such as a tert-butyl group. Among these alicyclic hydrocarbon groups, a group consisting of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane or cyclohexane, a group consisting of these alicyclic rings, A group in which an atom is substituted with the alkyl group is preferable.

In addition, as the derivative of the alicyclic hydrocarbon group, in the alicyclic hydrocarbon group, a hydrogen atom is a hydroxyl group; a carboxyl group; an oxo group (that is, ═O group); a hydroxymethyl group, 1-hydroxy Ethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group A C1-C4 hydroxyalkyl group such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, tert-butoxy group, etc. C1-C4 alkoxyl group; cyano group; cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl , Such substituted radicals with one or more, or one or more such cyanoalkyl group having 2 to 5 carbon atoms such as 4-cyanobutyl group.
Among these, a group substituted with a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, a cyanomethyl group, or the like is preferable.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms as R ⁴ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methylpropyl group, 1 -A methylpropyl group, a tert-butyl group, etc. are mentioned.
Of these alkyl groups, a methyl group, an ethyl group, an n-propyl group, and an isopropyl group are preferable.

Here, preferable examples of the repeating unit (1b) include (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-methyl-3-hydroxyadamantyl-2-yl ester, ( (Meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyl-3-hydroxyadamantyl-2-yl ester, (meth) acrylic acid 2-n-propyladamantyl-2-yl ester, (Meth) acrylic acid 2-isopropyladamantyl-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-2-ethylbicyclo [ 2.2.1] Hept-2-yl ester, (meth) acrylic acid-8-methyltricyclo [5.2.1] 0 ^2,6] decan-8-yl ester, (meth) ethyl-8-acrylic acid tricyclo [5.2.1.0 ^2,6] decan-8-yl ester, (meth) acrylic acid-4- Methyltetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid-4-ethyltetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid 1- (bicyclo [2.2.1] hept-2-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tetracyclo [6.2.1 ^3,6.0 0.0 ^2,7 ] dodecane -4-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1- (3-hydroxyadamantan-1-yl) -1-methyl ethyl ester, (meth) acrylic acid 1,1-dicyclohexylethyl ester, (meth) acrylic acid 1,1-di (bicyclo [2.2.1] hept-2-yl) ethyl ester, Meth) acrylic acid 1,1-di (tricyclo [5.2.1.0 ^2,6] decan-8-yl) ethyl ester, (meth) acrylic acid 1,1-di (tetracyclo [6.2.1 ^3,6 .0 ^2,7] dodecane-4-yl) ethyl ester, (meth) acrylic acid 1,1-di (adamantan-1-yl) ethyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl Ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester, and the like. Particularly preferable repeating unit (1b) includes (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid. 2-ethyladamantyl-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid- 2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 1- (bicyclo [2.2.1] hept-2-yl) -1-methylethyl ester, (meth) Examples include acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, and (meth) acrylic acid 1-ethyl-1-cyclohexyl ester.

  Moreover, resin [A] in this invention may contain only 1 type of the said repeating unit (1b), and may contain 2 or more types.

Resin [A] which concerns on this invention may be resin containing "the other repeating unit" which does not have a structure which expresses alkali solubility by the effect | action of an acid other than the said repeating unit [1].
Other repeating units are not particularly limited, and examples thereof include units containing a lactone structure (hereinafter referred to as repeating unit [2]).
Specific examples of the repeating unit [2] include units represented by the following general formulas (f-1) to (f-6).

〔各式中、Ｒ^５は、水素原子であり、Ｒ^６は、水素原子又はメトキシ基である。Ａは、単結合又はメチレン基であり、Ｂは、酸素原子又はメチレン基である。ｌは、１〜３の整数であり、ｍは、０又は１である。〕

[In each formula, R ⁵ is a hydrogen atom, and R ⁶ is a hydrogen atom or a methoxy group. A is a single bond or a methylene group, and B is an oxygen atom or a methylene group. l is an integer of 1 to 3, and m is 0 or 1. ]

In the unit containing the lactone structure represented by the general formulas (f-1) to (f-6), the main chain skeleton is not particularly limited, but is preferably a (meth) acrylate structure or α-tri It has a fluoroacrylic ester structure.
Therefore, among the monomers forming the units containing the lactone structure represented by the general formulas (f-1) to (f-6), preferred compounds include (meth) acrylic acid-5-oxo-4. -Oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1. 0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5-oxo-4-oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic Acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5.2.1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl Steal, (meth) acrylic acid-4-methoxycarbonyl-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa- Bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (Meth) acrylic acid-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxo Tetrahydropyran-4-yl ester, (meth) acrylic acid-4-propyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5- Oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2,2-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl Ester, (meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5- Dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid -3,3-dimethyl-5-oxotetrahydrofuran - yl methyl ester, and (meth) -4,4-dimethyl-5-oxo-tetrahydrofuran-2-yl methyl ester and acrylic acid.

Furthermore, examples of the other repeating units include repeating units represented by the following general formulas (3) to (5). Hereinafter, the repeating unit represented by the general formula (3) is referred to as “repeating unit [3]”, the repeating unit represented by the general formula (4) is referred to as “other repeating unit (4)”, and the general formula (5). ) Is referred to as “another repeating unit (5)”.
In addition, resin [A] in this invention may contain only 1 type of the said other repeating unit, and may contain 2 or more types.

〔式中、Ｒ^７は、水素原子、メチル基又はトリフルオロメチル基であり、Ｘは、炭素数７〜２０の多環型脂環式炭化水素基である。〕

[Wherein, R ⁷ represents a hydrogen atom, a methyl group or a trifluoromethyl group, and X represents a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. ]

〔式中、Ｒ^８は、水素原子、メチル基又はトリフルオロメチル基であり、Ｒ^９は、２価の有機基である。〕

[Wherein R ⁸ represents a hydrogen atom, a methyl group or a trifluoromethyl group, and R ⁹ represents a divalent organic group. ]

〔式中、Ｒ^１０は、水素原子、メチル基又はトリフルオロメチル基であり、Ｙは、炭素数１〜３の２価の有機基であり、Ｚは、互いに独立して、単結合又は炭素数１〜３の２価の有機基であり、Ｒ^１１は、互いに独立して、水素原子、ヒドロキシル基、シアノ基又は−ＣＯＯＲ^１２基（但し、Ｒ^１２は、水素原子或いは炭素数１〜４の直鎖状若しくは分岐状のアルキル基、又は、炭素数３〜２０の脂環式のアルキル基を表す。）である。〕

[Wherein, R ¹⁰ is a hydrogen atom, a methyl group or a trifluoromethyl group, Y is a divalent organic group having 1 to 3 carbon atoms, and Z is independently a single bond or carbon R ¹¹ is a hydrogen atom, a hydroxyl group, a cyano group or a —COOR ¹² group (provided that R ¹² is a hydrogen atom or a carbon number of 1 to 4). Represents a linear or branched alkyl group or an alicyclic alkyl group having 3 to 20 carbon atoms. ]

In the repeating unit represented by the general formula (3), X is a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms, and the following bicyclo [2.2.1] heptane (3a ), Bicyclo [2.2.2] octane (3b), tricyclo [5.2.1.0 ^2,6 ] decane (3c), tetracyclo [6.2.1.1 ^3,6 . And hydrocarbon groups containing an alicyclic ring derived from cycloalkanes such as 0 ^2,7 ] dodecane (3d) and tricyclo [3.3.1.1 ^3,7 ] decane (3e).

  In the hydrocarbon groups represented by the above embodiments (3a) to (3e), when two hydrogen atoms are bonded to a carbon atom, the hydrogen atom is a straight chain having 1 to 4 carbon atoms, Branched or cyclic alkyl group (methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group, etc.), hydroxyl group, cyano Group, a carboxyl group, or a C1-C10 hydroxyalkyl group may be substituted.

Accordingly, among the monomers forming the repeating unit represented by the general formula (3), preferred compounds include (meth) acrylic acid 2-bicyclo [2.2.1] heptyl ester, (meth) acrylic. Acid 2-bicyclo [2.2.2] octyl ester, (meth) acrylic acid 8-tricyclo [5.2.1.0 ^2,6 ] decanyl ester, (meth) acrylic acid 9-tetracyclo [6.2 1.1 ^{3, 6} . 0 ^2,7 ] dodecanyl ester, (meth) acrylic acid 1-tricyclo [3.3.1.1 ^3,7 ] decanyl ester, (meth) acrylic acid 2-tricyclo [3.3.1.1 ^{3 , 7} ] decanyl ester and the like.

In the repeating unit represented by the general formula (4), R ⁹ is a divalent organic group. Examples of the divalent organic group include a hydrocarbon group, an alkylene glycol group, and an alkylene ester group. Of these, hydrocarbon groups are preferred, and may be chain-like or cyclic.
Chain hydrocarbon groups include methylene, ethylene, 1,3-propylene, 1,2-propylene and other propylene groups, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octane Methylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group Methylene group, insalene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, ethylidene group, propylidene group, 2-propylidene group, etc. It includes sums chain hydrocarbon group. The cyclic hydrocarbon group includes a cyclobutylene group such as a 1,3-cyclobutylene group, a cyclopentylene group such as a 1,3-cyclopentylene group, and a cyclohexylene group such as a 1,4-cyclohexylene group. A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms such as a cyclooctylene group such as a 1,5-cyclooctylene group; a 1,4-norbornylene group, a 2,5-norbornylene group, etc. Bridged cyclic hydrocarbon ring groups having 4 to 30 carbon atoms such as 2 to 4 cyclic hydrocarbon ring groups such as adamantylene groups such as norbornylene group, 1,5-adamantylene group and 2,6-adamantylene group Etc.

In the case where R ⁹ is a divalent aliphatic cyclic hydrocarbon group, an alkylene group having 1 to 4 carbon atoms as a spacer between the bistrifluoromethyl-hydroxy-methyl group and the aliphatic cyclic hydrocarbon group. Is preferably inserted.
R ⁹ in the general formula (4) is preferably a hydrocarbon group containing a 2,5-norbornylene group, a 1,2-ethylene group, or a propylene group.

  Accordingly, among the monomers forming the repeating unit represented by the general formula (4), preferred compounds include (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2). -Hydroxy-3-propyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1, 1-trifluoro-2-trifluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) Ester, (meth) acrylic acid 2-{[5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2 1] heptyl} ester.

  In the repeating unit represented by the general formula (5), Y is a divalent organic group having 1 to 3 carbon atoms, and Z is independently a single bond or a divalent group having 1 to 3 carbon atoms. Is an organic group. Examples of these divalent organic groups having 1 to 3 carbon atoms include a methylene group, an ethylene group, and a propylene group.

In the repeating unit represented by the general formula (5), R ¹¹ is independently a hydrogen atom, a hydroxyl group, a cyano group, or a —COOR ¹² group. ^{Incidentally, R 11} is -COOR ¹² group where ^{R 12} is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or an alkyl alicyclic having 3 to 20 carbon atoms It is a group.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, Examples thereof include a tert-butyl group.
Examples of the alicyclic alkyl group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group represented by -C _n H _2n-1 (n is an integer of 3 to 20), A cycloalkyl group (monocyclic alicyclic alkyl group) such as a cycloheptyl group and a cyclooctyl group; a bicyclo [2.2.1] heptyl group, a tricyclo [5.2.1.0 ^2,6 ] decyl group, Tetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecanyl group, polycyclic alicyclic alkyl group such as adamantyl group and the like. In addition, the hydrogen atom in the alicyclic alkyl group may be a group formed by substitution with one or more linear, branched, or cyclic alkyl groups.

  Accordingly, among the monomers forming the repeating unit represented by the general formula (5), (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantane -1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) Acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-ylmethyl ester, and the like are preferable.

  In addition, the resin [A] may contain “another repeating unit” other than the above. Examples of the compound that forms such a repeating unit include (meth) acrylic acid, (meth) acrylic acid ester having a bridged hydrocarbon skeleton, (meth) acrylic acid ester having no bridged hydrocarbon skeleton, Carboxyl group-containing unsaturated carboxylic acid ester having a bridged hydrocarbon skeleton, carboxyl group-containing unsaturated carboxylic acid ester having no bridged hydrocarbon skeleton, and a polyfunctional monomer having a bridged hydrocarbon skeleton And a polyfunctional monomer having no bridged hydrocarbon skeleton.

  Examples of the (meth) acrylic acid ester having a bridged hydrocarbon skeleton include dicyclopentenyl (meth) acrylate and adamantylmethyl (meth) acrylate.

  Examples of the (meth) acrylic acid ester having no bridged hydrocarbon skeleton include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and n- (meth) acrylic acid. Butyl, 2-methylpropyl (meth) acrylate, 1-methylpropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxy (meth) acrylate Propyl, cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-methoxycyclohexyl (meth) acrylate, 2-cyclopentyloxycarbonylethyl (meth) acrylate, (meth) acryl Acid 2-cyclohexyloxycarbonylethyl, (meth) acrylic 2- (4 methoxycyclohexyl) oxycarbonyl ethyl, and the like.

  Examples of the carboxyl group-containing unsaturated carboxylic acid ester having a bridged hydrocarbon skeleton include carboxynorbornyl (meth) acrylate, carboxytricyclodecanyl (meth) acrylate, and carboxytetracycloun (meth) acrylate. Decanyl etc. are mentioned.

  Examples of the carboxyl group-containing unsaturated carboxylic acid ester having no bridged hydrocarbon skeleton include methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, α- N-butyl hydroxymethyl acrylate, (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, (meth) acrylic acid 4 -Carboxybutyl, (meth) acrylic acid 4-carboxycyclohexyl, etc. are mentioned.

  Examples of the multifunctional monomer having a bridged hydrocarbon skeleton include 1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di ( And (meth) acrylate, tricyclodecanyldimethylol di (meth) acrylate, and the like.

  Examples of the multifunctional monomer having no bridged hydrocarbon skeleton include methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and 1,6-hexanediol. Di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1, Examples thereof include 4-bis (2-hydroxypropyl) benzenedi (meth) acrylate and 1,3-bis (2-hydroxypropyl) benzenedi (meth) acrylate.

Among these, a unit in which a polymerizable unsaturated bond of (meth) acrylic acid ester having a bridged hydrocarbon skeleton is cleaved is preferable.
In addition, resin [A] in this invention may contain only 1 type of the said further another repeating unit, and may contain 2 or more types.

In the resin (A), the content of the repeating units (1a) and (1b) is for all resins, regardless of whether the resin is one kind or two or more kinds. When the total amount of repeating units constituting each resin is 100 mol%, it is usually 10 to 80 mol%, preferably 15 to 70 mol%, and more preferably 20 to 70 mol%. In this case, if the content of the repeating unit (1) is less than 10 mol%, the resolution as a resist may be lowered. On the other hand, if it exceeds 80 mol%, the exposure margin may be deteriorated.
Further, the content of the repeating unit (2) is usually 10 to 70 mol%, preferably 15 to 65 when the total amount of the repeating units constituting each resin is 100 mol% for all resins. It is mol%, More preferably, it is 20-60 mol%. In this case, when the content of the repeating unit (2) is less than 10 mol%, the resist has poor solubility in an alkaline developer, which may contribute to development defects or deteriorate the exposure margin. The exposure margin indicates a change in line width with respect to a change in exposure amount. On the other hand, when it exceeds 70 mol%, the solubility of the resist in the solvent is lowered, and the resolution may be lowered.
Further, the content of the repeating unit (3) is usually 30 mol% or less, preferably 25 mol% or less when the total amount of the repeating units constituting each resin is 100 mol% for all resins. It is. In this case, if the content of the repeating unit (3) exceeds 30 mol%, the resulting resist film may be easily swollen by the alkali developer or the solubility in the alkali developer may be reduced.
The content of the repeating unit (4) is usually 30 mol% or less, preferably 25 mol% or less, assuming that the total amount of the repeating units constituting each resin is 100 mol% for all resins. It is. In this case, if the content of the repeating unit (4) exceeds 30 mol%, the top loss of the resist pattern may occur and the pattern shape may be deteriorated.
Further, the content of the repeating unit (5) is usually 30 mol% or less, preferably 25 mol% or less when the total amount of the repeating units constituting each resin is 100 mol% for all resins. It is. In this case, if the content of the repeating unit (5) exceeds 30 mol%, the resulting resist film may be easily swollen by the alkali developer or the solubility in the alkali developer may be reduced.
Furthermore, the content of other repeating units is usually 50 mol% or less, preferably, for all resins, when the total amount of repeating units constituting each resin is 100 mol%. It is 40 mol% or less.

  The polystyrene-converted weight average molecular weight (hereinafter referred to as “Mw”) of the resin [A] by gel permeation chromatography (GPC) is not particularly limited, but is preferably 1000-100000, more preferably 1000-30000, Preferably it is 1000-20000. By being the said range, it is excellent in developability and heat resistance when forming a resist pattern. The ratio (Mw / Mn) of Mw of the resin [A] and the number average molecular weight (hereinafter referred to as “Mn”) in terms of polystyrene by gel permeation chromatography (GPC) is usually 1 to 5, Preferably it is 1-3.

The resin [A] requires a polymerizable unsaturated monomer corresponding to each repeating unit, using radical polymerization initiators such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. Accordingly, it can be produced by polymerizing in a suitable solvent in the presence of a chain transfer agent. Examples of the solvent include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin and norbornane; Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene; ethyl acetate, n-butyl acetate, acetic acid Saturated carboxylic acid esters such as isobutyl and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; ethers such as tetrahydrofuran, dimethoxyethanes and diethoxyethanes Is mentioned. These solvents can be used alone or in combination of two or more.
The reaction temperature during the polymerization is usually 40 to 150 ° C, preferably 50 to 120 ° C, and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

In the resin [A], the content of the low molecular weight component derived from the monomer produced during the production of the resin [A] is preferably 0.1% with respect to 100% by mass of the resin [A]. It is not more than mass%, more preferably not more than 0.07 mass%, still more preferably not more than 0.05 mass%. When the content of the low molecular weight component is 0.1% by mass or less, a substance that is eluted when the photoresist film is placed in an immersion exposure liquid such as water during immersion exposure. The amount can be reduced. In addition, it is possible to suppress uneven coating when applying the composition of the present invention, no foreign matter is generated on the surface of the photoresist film during storage of the product comprising the obtained photoresist film, It is possible to suppress the occurrence of defects when forming a resist pattern.
The low molecular weight component derived from the monomer can be analyzed by high performance liquid chromatography (HPLC) of the resin [A], and includes a monomer, a dimer, a trimer, an oligomer, and the like. The following components. The components having an Mw of 500 or less are removed by, for example, chemical purification methods such as washing with water and liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. can do.
Therefore, the resin [A] used in preparing the composition of the present invention is preferably as the content of impurities such as halogen, metal, etc. including the low molecular weight component derived from the monomer is smaller. It is possible to further improve the sensitivity, resolution, process stability, pattern shape and the like when a film is formed and then exposed, developed, and the like.

1-2. Radiation-sensitive acid generator The radiation-sensitive acid generator (hereinafter also referred to as “acid generator [B]”) according to the present invention is applied to the photoresist film by exposing the photoresist film to exposure (exposure). It is a compound that generates acid. An acid generated from the acid generator [B] by exposure acts on the resin [A] containing the repeating unit [1] having a structure that expresses alkali solubility by the action of an acid. The acid dissociable group is dissociated (the protecting group is eliminated). As a result, the exposed portion of the photoresist film becomes readily soluble in an alkali developer, and a positive resist pattern is formed.

  The acid generator [B] can be used singly or in combination of two or more, but a compound represented by the following general formula (6) (hereinafter referred to as “acid generator 1”). It is preferable to include.

〔式中、Ｒ^１３は、水素原子、フッ素原子、ヒドロキシル基、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、炭素数１〜１０の直鎖状若しくは分岐状のアルコキシル基、又は、炭素数２〜１１の直鎖状若しくは分岐状のアルコキシカルボニル基であり、Ｒ^１４は、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、炭素数１〜１０のアルコキシル基、又は、炭素数１〜１０の直鎖状、分岐状、環状のアルカンスルホニル基であり、Ｒ^１５は、互いに独立して、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、置換基を有してもよいフェニル基或いは置換基を有してもよいナフチル基であるか、又は、２つのＲ^１５が互いに結合してなり、置換基を有してもよい炭素数２〜１０の２価の基である。また、Ｘ⁻は、Ｒ^１６Ｃ_ｎＦ_２ｎＳＯ_３ ⁻或いはＲ^１６ＳＯ_３ ⁻（式中、Ｒ^１６は、フッ素原子、又は、置換基を有してもよい炭素数１〜１２の炭化水素基であり、ｎは、１〜１０の整数である。）で表されるアニオン、又は、下記一般式（７−１）或いは（７−２）で表されるアニオンである。ｒは０〜１０の整数であり、ｋは、０〜２の整数である。〕

[Wherein, R ¹³ represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or , A linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms, and R ¹⁴ is a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or , A linear, branched, or cyclic alkanesulfonyl group having 1 to 10 carbon atoms, and R ¹⁵ is independently of each other a linear or branched alkyl group having 1 to 10 carbon atoms or a substituent. It may be a phenyl group which may have a substituent or a naphthyl group which may have a substituent, or two R ^15's may be bonded to each other and may have a substituent. Is a valent group. X ⁻ represents R ¹⁶ C _n F _2n SO ₃ ^— or R ¹⁶ SO ₃ ^— (wherein R ¹⁶ is a fluorine atom or a hydrocarbon having 1 to 12 carbon atoms which may have a substituent. N is an integer of 1 to 10), or an anion represented by the following general formula (7-1) or (7-2). r is an integer of 0 to 10, and k is an integer of 0 to 2. ]

〔式中、Ｒ^１７は、独立に炭素数１〜１０の直鎖状若しくは分岐状のフッ素原子を含有するアルキル基を示すか、或いは２個のＲ^１７が互いに結合して炭素数２〜１０の２価のフッ素原子を含有する基を形成しており、該２価の基は置換されていてもよい。〕

[Wherein, R ¹⁷ independently represents an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms, or two R ¹⁷ are bonded to each other to form 2 to 10 carbon atoms. A group containing a divalent fluorine atom is formed, and the divalent group may be substituted. ]

In the general formula (6), when R ¹³ , R ¹⁴ and R ¹⁵ are a linear or branched alkyl group having 1 to 10 carbon atoms, a methyl group, an ethyl group, an n-propyl group, an isopropyl group N-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group , N-nonyl group, n-decyl group and the like. Of these, a methyl group, an ethyl group, an n-butyl group, a tert-butyl group and the like are preferable.

Moreover, when R < ¹³ > and R < ¹⁴ > is a C1-C10 linear or branched alkoxyl group, a methoxy group, an ethoxy group, n-propoxy group, an isopropoxy group, n-butoxy group, 2- Methylpropoxy group, 1-methylpropoxy group, tert-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, An n-nonyloxy group, an n-decyloxy group, etc. are mentioned. Of these, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

When R ¹³ is a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, 2 -Methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, tert-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, n-octyloxy Examples include carbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like. Of these, methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group and the like are preferable.

When R ¹⁴ is a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a tert-butanesulfonyl group Group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n-nonanesulfonyl group, n-decanesulfonyl group, cyclo A pentanesulfonyl group, a cyclohexanesulfonyl group, etc. are mentioned. Of these, methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl group, n-butanesulfonyl group, cyclopentanesulfonyl group, cyclohexanesulfonyl group and the like are preferable.

  R is an integer of 0 to 10, preferably 0, 1 or 2.

R ¹⁵ in the general formula (6) may be a phenyl group or a phenyl group having a substituent. In the latter case, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-fluoro Examples thereof include a phenyl group substituted with a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms such as a phenyl group.

In the above phenyl group and alkyl-substituted phenyl group, one or more hydrogen atoms are replaced by a hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, alkoxycarbonyloxy group, etc. It can also be a substituted group.
Examples of the alkoxyl group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, tert-butoxy group, cyclopentyloxy group, and cyclohexyloxy group. And a linear, branched or cyclic alkoxyl group having 1 to 20 carbon atoms.
Examples of the alkoxyalkyl group include linear chains having 2 to 21 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. And a branched or cyclic alkoxyalkyl group.
Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, tert-butoxycarbonyl. A linear, branched or cyclic alkoxycarbonyl group having 2 to 21 carbon atoms such as a group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like.
Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an isopropoxycarbonyloxy group, an n-butoxycarbonyloxy group, a tert-butoxycarbonyloxy group, and a cyclopentyloxycarbonyl. And a straight-chain, branched or cyclic alkoxycarbonyloxy group having 2 to 21 carbon atoms, such as a group and cyclohexyloxycarbonyl.

When R ¹⁵ in the general formula (6) is an optionally substituted phenyl group, a phenyl group, 4-cyclohexylphenyl group, 4-tert-butylphenyl group, 4-methoxyphenyl group, 4-tert- A butoxyphenyl group and the like are preferable.

Further, R ¹⁵ in the general formula (6) may be a 1-naphthyl group or a 2-naphthyl group, or may be a naphthyl group having a substituent. In the latter case, 1-naphthyl group, 2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1 -Naphtyl group, 6-methyl-1-naphthyl group, 7-methyl-1-naphthyl group, 8-methyl-1-naphthyl group, 2,3-dimethyl-1-naphthyl group, 2,4-dimethyl-1- Naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6-dimethyl-1-naphthyl group, 2,7-dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4 -Dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl group, 3,6-dimethyl-1-naphthyl group, 3,7-dimethyl-1-naphthyl group, 3,8-dimethyl-1-naphthyl Group, 4,5-dimethyl-1-naphthyl group, 5,8 1-10 carbon atoms such as dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group, 1-methyl-2-naphthyl group, 3-methyl-2-naphthyl group, 4-methyl-2-naphthyl group, etc. And a naphthyl group substituted with a linear, branched or cyclic alkyl group.

In the above naphthyl group and alkyl-substituted naphthyl group, one or more hydrogen atoms are replaced by hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, alkoxycarbonyloxy group, etc. It can also be a substituted group.
For the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group and alkoxycarbonyloxy group, the groups exemplified in the description of the alkyl-substituted phenyl group can be applied.

When R ¹⁵ in the general formula (6) is an optionally substituted naphthyl group, 1-naphthyl group, 1- (4-methoxynaphthyl) group, 1- (4-ethoxynaphthyl) group, 1- (4-n-propoxynaphthyl) group, 1- (4-n-butoxynaphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n-propoxy) A naphthyl) group, a 2- (7-n-butoxynaphthyl) group, and the like are preferable.

Also, if the formula (6) two R ¹⁵ that binds to a sulfur atom in the is comprised bonded to each other, a divalent group having carbon atoms of 2-10 that may have a substituent, said sulfur A 5-membered or 6-membered ring, particularly preferably a 5-membered ring (that is, a tetrahydrothiophene ring) is preferably formed together with the atoms. In the case where the divalent group has a substituent, one or more hydrogen atoms may be substituted with hydroxyl group, carboxyl group, cyano group, nitro group, alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, alkoxycarbonyloxy group, etc. It can also be a group formed by substitution.
For the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group and alkoxycarbonyloxy group, the groups exemplified in the description of the alkyl-substituted phenyl group can be applied.

From the above, as R ¹⁵ in the general formula (6), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ¹⁵ are bonded to each other to form a tetrahydrothiophene ring together with a sulfur atom. A divalent group constituting the structure is preferred.
Accordingly, preferred cation sites in the general formula (6) include triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, di-4- Fluorophenyl-phenylsulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl-diphenylsulfonium cation, 4-methanesulfonylphenyl-diphenylsulfonium cation, 4-cyclohexanesulfonyl-diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation 1-naphthyl diethylsulfonium cation, 1- (4-hydroxynaphthyl) dimethylsulfonium cation ON, 1- (4-methylnaphthyl) dimethylsulfonium cation, 1- (4-methylnaphthyl) diethylsulfonium cation, 1- (4-cyanonaphthyl) dimethylsulfonium cation, 1- (4-cyanonaphthyl) diethylsulfonium cation, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthyl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation, 2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxyna Chill) tetrahydrothiophenium cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) tetrahydrothiophenium cation, and the like.

The C _n F _2n — group in the anion represented by R ¹⁶ C _n F _2n SO ₃ ^— in X ⁻ in the general formula (6) is a perfluoroalkylene group having n carbon atoms. It can be linear or branched. Here, n is preferably 1, 2, 4 or 8.
In the anion represented by R ¹⁶ C _n F _2n SO ₃ ^— and R ¹⁶ SO ₃ ^— , the optionally substituted hydrocarbon group having 1 to 12 carbon atoms of R ¹⁶ may have 1 to 1 carbon atoms. Twelve alkyl groups, cycloalkyl groups, and bridged alicyclic hydrocarbon groups are preferred. Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group N-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl group Etc.

Furthermore, in the anions represented by the general formulas (7-1) and (7-2), R ¹⁷ independently represents an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms. Trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, dodecafluoropentyl group, perfluorooctyl group and the like.
Examples of the group in which two R ¹⁷ are bonded to each other and contain a divalent fluorine atom having 2 to 10 carbon atoms include a tetrafluoroethylene group, a hexafluoropropylene group, an octafluorobutylene group, and a decafluoropentylene group. Group, undecafluorohexylene group and the like.

  Accordingly, preferred anion sites in the general formula (6) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hepta- 2-yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, and the following formula (8-1): And anions represented by (8-7).

  Examples of the acid generator 1 include triphenylsulfonium trifluoromethanesulfonate, tri-tert-butylphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium trifluoromethanesulfonate, 1 -(3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, triphenylsulfonium perfluoro-n-butanesulfonate, Tri-tert-butylphenylsulfonium perfluoro-n-butanesulfonate, 4-cycl Hexylphenyl-diphenylsulfonium perfluoro-n-butanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium perfluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro- n-butanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, tri-tert-butylphenylsulfonium perfluoro-n- Octane sulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-octane sulfonate, 4-methanesulfonylphenyl-diphenylsulfonium -Fluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-octanesulfonate, triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- ( Bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-Methanesulfonylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4 -Hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthyl) Tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (bicyclo [2.2.1] Hepta-2'-yl) -1,1-difluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2.1] Pt-2'-yl) -1,1-difluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 4- Methanesulfonylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] ] Hepta-2′-yl) -1,1-difluoroethanesulfonate, the following formula (B1-1) ˜ B1-15), and the like.

  In addition, these acid generators 1 can be used individually by 1 type or in combination of 2 or more types.

  Further, a radiation sensitive acid generator other than the acid generator 1 (hereinafter referred to as “other acid generator”) can also be used. For example, an onium salt compound, a halogen-containing compound, a diazoketone compound, a sulfone compound, Examples thereof include sulfonic acid compounds.

Examples of the onium salt compounds include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.
Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta-2. -Yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis ( 4-tert-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-tert-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2- 1,2,2,2-tetrafluoroethanesulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, etc. Can be mentioned.

Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds.
Specific examples of halogen-containing compounds include (trichloromethyl such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine. ) -S-triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

Examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like.
Specific examples of the diazoketone compound include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 1,2-naphtho of 2,3,4,4′-tetrahydroxybenzophenone. Quinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane or 1 , 2-naphthoquinonediazide-5-sulfonic acid ester and the like.

Examples of the sulfone compound include β-ketosulfone compounds, β-sulfonylsulfone compounds, α-diazo compounds of these compounds, and the like.
Specific examples of the sulfone compound include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like.

Examples of the sulfonic acid compounds include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates.
Specific examples of the sulfonic acid compound include benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept- 5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2 .1] Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2. 1] Hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyl Xyl) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic acid imidononafluoro-n-butanesulfonate, 1,8-naphthalenedicarboxylic acid And acid imido perfluoro-n-octane sulfonate.
The other acid generators can be used singly or in combination of two or more.

Among the other acid generators, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta-2 -Yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis ( 4-tert-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-tert-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1, , 2,2-tetrafluoroethane sulfonate,
Cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate,

  Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2 1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate and the like are preferable.

  In the composition of the present invention, the content of the acid generator [B] is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin [A] from the viewpoint of ensuring sensitivity and developability as a resist. Part, more preferably 0.5 to 10 parts by mass. If the content of the acid generator [B] is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, if the content exceeds 20 parts by mass, the transparency to radiation decreases and a rectangular resist. It tends to be difficult to obtain a pattern. When the acid generator 1 is used in combination with another acid generator, the use ratio of the other acid generator is usually 80% by mass with respect to 100% by mass of the acid generator [B]. Hereinafter, it is preferably 60% by mass or less.

1-3. Nitrogen-containing compound The nitrogen-containing compound according to the present invention (hereinafter also referred to as “nitrogen-containing compound [C]”) is a nitrogen-containing compound other than the acid generator [B], and is exposed to an acid generator [B]. It acts as an acid diffusion control agent that controls the diffusion phenomenon of acid generated in the resist film and suppresses undesired chemical reactions in non-exposed areas. Further, by blending this nitrogen-containing compound [C], the radiation-sensitive resin composition is excellent in storage stability, the resolution as a resist is further improved, and the holding time from exposure to heat treatment after exposure is also provided. Changes in the line width of the resist pattern due to fluctuations in (PED) can be suppressed, and the process stability is extremely excellent.
Examples of the nitrogen-containing compound [C] include tertiary amine compounds, amide group-containing compounds, quaternary ammonium hydroxide compounds, and nitrogen-containing heterocyclic compounds.

  Examples of the tertiary amine compound include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n- Tri (cyclo) alkylamines such as octylamine, cyclohexyldimethylamine, dicyclohexylmethylamine, tricyclohexylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4- Aromatic amines such as methylaniline, 4-nitroaniline, 2,6-dimethylaniline and 2,6-diisopropylaniline; alkanolamines such as triethanolamine and N, N-di (hydroxyethyl) aniline; N, N ', N'-tetramethylethylene Amine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, bis (2- Dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, and the like.

  Examples of the amide group-containing compound include N-tert-butoxycarbonyldi-n-octylamine, N-tert-butoxycarbonyldi-n-nonylamine, N-tert-butoxycarbonyldi-n-decylamine, and N-tert. -Butoxycarbonyldicyclohexylamine, N-tert-butoxycarbonyl-1-adamantylamine, N-tert-butoxycarbonyl-2-adamantylamine, N-tert-butoxycarbonyl-N-methyl-1-adamantylamine, (S)- (-)-1- (tert-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (tert-butoxycarbonyl) -2-pyrrolidinemethanol, N-tert-butoxycarbonyl-4-hydroxy Piperidine, -Tert-butoxycarbonylpyrrolidine, N-tert-butoxycarbonylpiperazine, N, N-di-tert-butoxycarbonyl-1-adamantylamine, N, N-di-tert-butoxycarbonyl-N-methyl-1-adamantylamine N-tert-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-tert-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-tert-butoxycarbonylhexamethylenediamine, N, N′-di-tert-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-tert-butoxycarbonyl-1,8-diaminooctane, N, N′-di-tert-butoxycarbonyl- 1,9-diaminononane, N, N′-di tert-butoxycarbonyl-1,10-diaminodecane, N, N′-di-tert-butoxycarbonyl-1,12-diaminododecane, N, N′-di-tert-butoxycarbonyl-4,4′-diaminodiphenylmethane N-tert-butoxycarbonyl group-containing amino compounds such as N-tert-butoxycarbonylbenzimidazole, N-tert-butoxycarbonyl-2-methylbenzimidazole, N-tert-butoxycarbonyl-2-phenylbenzimidazole, etc. It is done.

  Examples of the quaternary ammonium hydroxide compound include tetra-n-propylammonium hydroxide and tetra-n-butylammonium hydroxide.

Examples of the nitrogen-containing heterocyclic compound include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenyl. Pyridines such as pyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline and acridine; piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, as well as pyrazine and pyrazole , Pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, Imidazole, 4-methylimidazole 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, N-tert-butoxycarbonylbenzimidazole, N-tert-butoxycarbonyl-2-methylbenzimidazole, N -Tert-butoxycarbonyl-2-phenylbenzimidazole and the like.
The said nitrogen-containing compound [C] can be used individually by 1 type or in combination of 2 or more types.

  In the composition of the present invention, the content of the nitrogen-containing compound [C] is preferably less than 10 parts by mass with respect to 100 parts by mass of the resin [A], more preferably from the viewpoint of ensuring high sensitivity as a resist. Less than 5 parts by weight. However, the lower limit is usually 0.001 part by mass. When the content of the nitrogen-containing compound [C] is too large, the sensitivity as a resist tends to be remarkably lowered. On the other hand, if the content of the nitrogen-containing compound [C] is too small, the pattern shape and dimensional stability as a resist may be lowered depending on the process conditions.

1-4. Solvent The solvent according to the present invention (hereinafter also referred to as “solvent [D]”) preferably dissolves the resin [A], the acid generator [B] and the nitrogen-containing compound [C]. 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3-dimethyl-2-butanone, 2-heptanone, Linear or branched ketones such as 2-octanone; cyclic ketones such as cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone; propylene glycol Monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl Propylene glycol mono, such as ether acetate, propylene glycol mono-isopropyl ether acetate, propylene glycol mono-n-butyl ether acetate, propylene glycol mono-isobutyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-tert-butyl ether acetate Alkyl ether acetates; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, n-propyl 2-hydroxypropionate, isopropyl 2-hydroxypropionate, n-butyl 2-hydroxypropionate, isobutyl 2-hydroxypropionate , 2-hydroxypropionic acid sec-butyl, 2-hydroxypropionic acid ter -Alkyl 2-hydroxypropionates such as butyl; other alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate ,

  n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether, propylene Glycol mono Chill ether, propylene glycol mono-n-propyl ether, toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, Ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethyl Glycol monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, etc. It is done.

Among these, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone, and the like are preferable.
The said solvent [D] can be used individually by 1 type or in combination of 2 or more types.

1-5. Additives In the radiation sensitive resin composition of the present invention, additives such as an alicyclic additive having an acid dissociable group, a surfactant, and a sensitizer can be blended as necessary.

The alicyclic additive having an acid dissociable group is a component that exhibits an action of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid, 2-adamantanone, tert-butyl 1-adamantanecarboxylate, tert-butoxycarbonylmethyl 1-adamantanecarboxylate, 1-adamantanecarboxylic acid α -Butyrolactone ester, 1,3-adamantane dicarboxylate di-tert-butyl, 1-adamantane acetate tert-butyl, 1-adamantane acetate tert-butoxycarbonylmethyl, 1,3-adamantane diacetate di-tert-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane; tert-butyl deoxycholic acid, tert-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, deoxy Deoxycholic acid esters such as 2-cyclohexyloxyethyl cholic acid, 3-oxocyclohexyl deoxycholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester of deoxycholic acid; tert-butyl lithocholic acid, tert-butoxycarbonyl lithocholic acid Lithocholic acid esters such as methyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate Alkyl carboxylic acid esters such as dipropyl adipate, di-n-butyl adipate, di-tert-butyl adipate, and 3- [2-hydroxy-2,2-bis ((Trifluoromethyl) ethyl) tetracyclo [4.4.0.12,5.17,10] dodecane and the like. These alicyclic additives can be used alone or in combination of two or more.

The surfactant is a component having an action of improving coating properties, striations, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, "KP341" (manufactured by Shin-Etsu Chemical Co., Ltd.), "Polyflow No. 75", "Polyflow No. 95" (above) , Kyoeisha Chemical Co., Ltd.), "F-top EF301", "F-top EF303", "F-top EF352" (above, manufactured by Tochem Products), "Megafax F171", "Megafax F173" ( Greater than Japan (Made by Ki Chemical Industry Co., Ltd.), “Florard FC430”, “Florard FC431” (manufactured by Sumitomo 3M Ltd.), “Asahi Guard AG710”, “Surflon S-382”, “Surflon SC-101”, “ Surflon SC-102 "," Surflon SC-103 "," Surflon SC-104 "," Surflon SC-105 "," Surflon SC-106 "(manufactured by Asahi Glass Co., Ltd.) and the like. These surfactants can be used alone or in combination of two or more.

The sensitizer absorbs radiation energy and transmits the energy to the acid generator [B], thereby increasing the amount of acid produced. The apparent appearance of the radiation-sensitive resin composition Has the effect of improving the sensitivity.
Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used alone or in combination of two or more.

  Examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like. Furthermore, by blending dyes or pigments, the latent image of the exposed area can be visualized, and the influence of halation during exposure can be mitigated. By blending an adhesion aid, adhesion to the substrate can be improved. it can.

1-6. Preparation of Composition The composition of the present invention has a total solid content of resin [A], acid generator [B], nitrogen-containing compound [C], and additives used as necessary. It can be prepared by dissolving each of the above-mentioned components in a solvent [D] so that the amount is preferably 1 to 50% by mass, more preferably 1 to 25% by mass. After dissolution, for removal of impurities, filtration may be performed using, for example, a filter having a pore size of about 0.2 μm.

2. Method for Forming Resist Pattern A method for forming a resist pattern of the present invention comprises a photoresist film forming step of applying a radiation-sensitive resin composition on a substrate to form a photoresist film, and a pre-application for the photoresist film. A baking step and immersion exposure in which a liquid for immersion exposure having a refractive index higher than that of air at a wavelength of 193 nm is interposed between the lens and the photoresist film to irradiate the photoresist film with radiation. A resist pattern forming method comprising: a step of performing post-exposure baking on the photoresist film; and a developing step of removing an exposed portion of the photoresist film with a developer. Radiation-sensitive resin composition used for forming resin and radiation-sensitive acid generation Agent, a nitrogen-containing compound, and contains a solvent, wherein the pre-application bake are performed by the temperature higher than the glass transition temperature of the resin, and the glass transition temperature of said resin of the pre-application bake The temperature difference is 5 to 50 ° C.
In the resist pattern forming method, in the step of performing the immersion exposure, the exposure may be performed in a state where an immersion exposure liquid is disposed on the surface of the photoresist film.

Here, the substrate used in the photoresist film forming step may be a substrate made of an inorganic material, or a composite substrate in which a lower antireflection film is formed on a substrate made of this inorganic material. Good.
As the substrate made of the inorganic substance, a metal such as silicon, aluminum, iron, ruthenium, tungsten, titanium, molybdenum, etc., which is not deformed or altered by the subsequent heat treatment; stainless steel, aluminum / silicon alloy, aluminum / silicon / copper A substrate made of an alloy or an alloy such as tungsten silicide can be used. A laminated substrate such as a wafer coated with aluminum can also be used. Also, in the subsequent immersion exposure process, if the irradiated radiation may be reflected on the substrate surface, halation and standing waves may occur, and a fine resist pattern may not be accurately reproduced. A composite substrate on which an antireflection film is formed is used. The lower antireflection film can be made of a known organic or inorganic material disclosed in Japanese Patent Application Laid-Open No. 59-93448. The thickness of the lower antireflection film is not particularly limited, but is usually in the range of 10 to 200 μm.

In the photoresist film forming step, the composition of the present invention is applied to the surface of the substrate or the surface of the lower antireflection film of the composite substrate by spin coating, casting coating, roll coating, etc. It is applied by a method, the solvent is removed by heat treatment (pre-application baking), a photoresist film is formed, and a substrate with a photoresist film (hereinafter referred to as “laminated substrate”) is obtained. The photoresist film may be a single layer or a plurality of layers. The film thickness is usually in the range of 50 to 500 μm. Furthermore, the conditions for the heat treatment are appropriately selected according to the composition of the photoresist film, the kind of the additive, etc., but the temperature is as described above, and the time is usually 5 to 300 seconds.
A schematic view of the laminated substrate is as shown in FIG. That is, the laminated substrate 2 of FIG. 2 is provided on a substrate 21 such as a silicon plate, a lower antireflection film 22 provided on one surface of the substrate 21, and a surface of the lower antireflection film 22. And a photoresist film 23.
If necessary, for example, in order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film such as that disclosed in JP-A-5-188598 is used. It can be disposed on the surface. This protective film usually has a property that does not cause mixing with the photoresist film, and is dissolved, altered, expanded, etc. by an immersion exposure liquid that will be contacted in a subsequent immersion exposure process. It has the property of not producing.

In the immersion exposure step, first, an immersion exposure liquid having a refractive index higher than that of air at a wavelength of 193 nm is disposed so as to cover at least the surface of the photoresist film of the multilayer substrate. Examples of the immersion exposure liquid include water; fluorine-based inert liquids such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F _7. Usually, water is used. Thereafter, an exposure lens is disposed on the liquid surface so that only one surface is in contact with the immersion exposure liquid. Then, the surface of the photoresist film is irradiated, that is, exposed to radiation such as visible light, ultraviolet light, far ultraviolet light, X-rays, and charged particle beams through a photomask having a mask pattern for forming a desired pattern. . Thereby, the radiation passes through the opening of the photomask, further passes through the exposure lens and the immersion exposure liquid (and the protective film), and reaches the photoresist film.
The radiation is selected according to the type of acid generator contained in the photoresist film, but far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) and KrF excimer laser (wavelength 248 nm) are preferable. In particular, an ArF excimer laser (wavelength 193 nm) is preferable. The exposure conditions such as the exposure amount are appropriately selected according to the composition of the photoresist film, the type of additive, and the like.

After the liquid immersion exposure step, the laminated substrate is taken out from the liquid for liquid immersion exposure and washed as necessary. When a protective film is formed on the surface of the photoresist film, the protective film may be removed at this time, or may be performed after the following post-exposure heating.
Thereafter, the laminated substrate provided with the exposed photoresist film is heated (hereinafter also referred to as “post-exposure heating (PEB)”) to smoothly dissociate the acid-dissociable groups of the resin contained in the photoresist film. Proceed. The conditions for the post-exposure heating are appropriately selected according to the composition of the photoresist film, the type of additive, and the like, but the temperature is usually 30 to 200 ° C., preferably 50 to 170 ° C. The time is usually 5 to 300 seconds.

  Next, in the development step, the exposed portion of the photoresist film is removed with a developer. This developer is an alkaline solution such as 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, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [ 4.3.0] An aqueous solution (alkaline aqueous solution) in which a compound such as 5-nonene is dissolved can be used. In this case, the solute may be one of the above compounds or two or more. When the developer is an aqueous solution (alkaline aqueous solution) in which the compound is dissolved, the concentration is usually 10% by mass or less. If this concentration is too high, the unexposed area may also be dissolved in the developer.

The developer may contain an organic solvent, a surfactant and the like. Examples of organic solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, 2,6-dimethylcyclohexanone, and the like; methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol , N-butyl alcohol, tert-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol and other alcohols; tetrahydrofuran, dioxane and other ethers; ethyl acetate, n-acetate -Esters such as butyl and isoamyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone, dimethylformamide and the like. These organic solvents can be used alone or in combination of two or more.
The amount of the organic solvent used is preferably 100% by volume or less when the alkaline aqueous solution is 100% by volume. If the amount of the organic solvent used exceeds 100% by volume, the developability may be deteriorated, resulting in a large amount of development residue in the exposed area.

  After the development step, a desired positive resist pattern can be obtained by taking out the laminated substrate from the developer, washing and drying. In addition, after baking, you may post-bake as needed.

  As described above, according to the method for forming a resist pattern of the present invention, the photoresist film has high resistance to immersion exposure liquid made of water or the like, and acts efficiently as a chemically amplified resist. Accordingly, a resist pattern having a fine structure such as a line-and-space pattern having a small pitch can be formed.

  Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the following, parts and% are based on mass unless otherwise specified.

Each measurement and evaluation in each of the following synthesis examples was performed in the following manner.
(1) Mw and Mn
Using a GPC column (2 G2000HXL, 1 G3000HXL and 1 G4000HXL) manufactured by Tosoh Corporation, gel permeation with monodisperse polystyrene as a standard under the conditions of elution solvent tetrahydrofuran, flow rate 1.0 ml / min and column temperature 40 ° C. It was subjected to an association chromatography (GPC) measurement to obtain a weight average molecular weight (Mw) and a number average molecular weight (Mn). Further, the degree of dispersion Mw / Mn was calculated from the measurement results.
(2) Amount of low molecular weight component derived from monomer Using an Intersil ODS-25 μm column (4.6 mmφ × 250 mm) manufactured by GL Sciences, eluent acrylonitrile / 0.1% phosphoric acid aqueous solution, and a flow rate of 1.0 The measurement was performed by high performance liquid chromatography (HPLC) under the condition of milliliter / minute, and the low molecular weight component was quantified.
^{(3) 13} C-NMR analysis of ¹³ C-NMR analysis the polymer, a CDCl ₃ as a measuring solvent was carried out using a Nippon Denshi Co. "JNM-EX270".
(4) Glass transition temperature (Tg)
Tg analysis of each polymer was measured using “DSC-3200S” manufactured by Mac Science. The sample was once heated to 150 ° C., cooled to room temperature, and measured from 40 to 200 ° C. at a temperature increase rate of 10 ° C./min. In addition, regarding the polymer in which Tg cannot be confirmed in this temperature range, it was set as “unmeasurable”.

1. Production of resin [A]
<Synthesis Example 1>
The following compound (M-1) 41.67 g (40 mol%), compound (M-2) 25.25 g (30 mol%), and compound (M-3) 33.07 g (30 mol%) -A monomer solution was prepared by dissolving 4.1 g of dimethyl 2,2'-azobis (2-methylpropionate) in 200 g of butanone. On the other hand, 100 g of 2-butanone was placed in a three-necked flask having a volume of 500 ml, and the inside was purged with nitrogen gas for 30 minutes. After purging with nitrogen, the mixture was heated to 80 ° C. with stirring, and the monomer solution was added dropwise through a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or lower by water cooling. Subsequently, this polymerization solution was put into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed on the slurry twice with 400 g of methanol. Thereafter, the product was collected by filtration and dried at 50 ° C. for 17 hours to obtain a white powder resin (68.9 g, yield 68.9%). As a result of ¹³ C-NMR analysis, this resin has a content ratio of each repeating unit derived from the compound (M-1), the compound (M-2) and the compound (M-3) as 51.2: 19, respectively. 8: 29.0 (mol%), Mw was 6200, Mw / Mn was 1.78, and Tg was 126 ° C. (hereinafter, this copolymer was referred to as “resin (A-1 ) "). In addition, content of the low molecular weight component derived from the monomer used for superposition | polymerization in this resin (A-1) was 0.02% with respect to 100% of this resin.

<Synthesis Example 2>
The following compound (M-1) 54.21 g (50 mol%), compound (M-2) 35.04 g (40 mol%), and compound (M-4) 10.74 g (10 mol%) -Polymerization was conducted in the same manner as in Synthesis Example 1 except that a monomer solution prepared by dissolving in 200 g of butanone and further adding 4.28 g of 2,2'-azobis (isobutyronitrile) was used. It was. As a result of ¹³ C-NMR analysis, the resin thus obtained has a content ratio of each repeating unit derived from the compound (M-1), the compound (M-2), and the compound (M-4) of 50, respectively. 0.8 mol%, 40.3 mol% and 8.9 mol% of copolymer, Mw was 6900, Mw / Mn was 1.82, and Tg was 122 ° C. "Resin (A-2)"). In addition, content of the low molecular weight component derived from the monomer used for superposition | polymerization in this resin (A-2) was 0.02% with respect to 100% of this resin.

<Synthesis Example 3>
The following compound (M-5) 53.93 g (50 mol%), compound (M-6) 35.38 g (40 mol%), and compound (M-7) 10.69 g (10 mol%) -In the same manner as in Synthesis Example 1 except that a monomer solution prepared by dissolving 5.58 g of dimethyl 2,2'-azobis (2-methylpropionate) and dissolving in 200 g of butanone was used. Polymerization was performed. As a result of ¹³ C-NMR analysis, the resin thus obtained had 52% content of each repeating unit derived from the compound (M-5), the compound (M-6), and the compound (M-7). .2 mol%, 39.2 mol%, and 8.6 mol%, and Mw was 7400 (hereinafter, this copolymer is referred to as “resin (A-3)”).
The Tg of this resin (A-3) could not be confirmed at the temperature until the weight phenomenon occurred.

<含窒素化合物〔Ｃ〕>
（Ｃ−１）：Ｎ−ｔｅｒｔ−ブトキシカルボニルピロリジン
<溶剤〔Ｄ〕>
（Ｄ−１）：プロピレングリコールモノメチルエーテルアセテート
（Ｄ−２）：γ−ブチロラクトン
（Ｄ−３）：シクロヘキサノン 2. Preparation and Evaluation of Radiation Sensitive Resin Composition Examples 1 to 3 and Comparative Examples 1 and 2
The resin [A] obtained as described above, the following acid generator [B], the nitrogen-containing compound [C], and the solvent [D] are mixed in the proportions shown in Table 1 to produce a radiation-sensitive resin composition. I got a thing.
<Acid generator [B]>
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (B-2): Compound having the following structure

<Nitrogen-containing compound [C]>
(C-1): N-tert-butoxycarbonylpyrrolidine
<Solvent [D]>
(D-1): Propylene glycol monomethyl ether acetate (D-2): γ-butyrolactone (D-3): Cyclohexanone

Next, the following evaluation was performed about the prepared radiation sensitive resin composition. Evaluation items and methods are as follows.
(1) Elution volume (elution volume of elution components)
In the following manner, the elution amount evaluation structure 1 shown in FIG. 1 is prepared, and the acid generator [B] and nitrogen-containing compound [C] eluted in the liquid for immersion exposure (ultra pure water) are quantified, It was confirmed whether the total amount of the eluted components was 5.0 × 10 ⁻¹² mol / (cm ² · sec) or more.
The surface of the 8-inch silicon plate 31 is preliminarily processed by a HMDS (hexamethyldisilazane) treatment (100 ° C., 60 seconds) using a resist coating / developing apparatus “CLEAN TRACK ACT8” manufactured by Tokyo Electron Co., Ltd. A silicon rubber sheet 4 (manufactured by Kureha Elastomer Co., Ltd., thickness: 1.0 mm, shape: square with a side of 30 cm) was placed at the center of the HMDS treated surface. Next, the hollow portion at the center of the silicon rubber sheet 4 was filled with 10 ml of ultrapure water (5 in FIG. 1) using a hole pipette having a capacity of 10 ml.
On the other hand, an antireflection film 22 (“ARC29A”, manufactured by Brewer Science Co., Ltd.) having a film thickness of 77 nm is formed on the surface of the 8-inch silicon plate 21 using the “CLEAN TRACK ACT8”, and then prepared as described above. The resulting radiation-sensitive resin composition was spin-coated on the antireflection film 22 using the above-mentioned apparatus, and the coating film was baked (PB) at a temperature of 115 ° C. for 60 seconds. A substrate 2 with a photoresist coating was obtained.
Next, the substrate 2 with the photoresist coating and the silicon rubber sheet 4 are combined with the ultrapure water in which the surface of the photoresist coating 23 of the substrate 2 with the photoresist coating is filled in the cut-out portion of the silicon rubber sheet 4. The ultrapure water was brought into close contact with the silicon rubber sheet 4 so as to come into contact with each other, and the elution amount evaluation structure 1 was produced (see FIG. 1).

Thereafter, this state was maintained for 10 seconds. The wafer 3 was removed, and ultrapure water was collected with a glass syringe (with a collection rate of 95% or more), and this was used as an analysis sample. The acid generator [B] and the nitrogen-containing compound [C] in this analysis sample are LC-MS (liquid chromatograph mass spectrometer, LC part: “SERIES1100” manufactured by AGILENT, MS part: PerSeptive Biosystems, Inc. ("Mariner") manufactured under the following conditions. From the peak intensity of each anion part of the detected acid generator [B] and nitrogen-containing compound [C], it was quantified by a calibration curve. Calibration curves were prepared from the peak intensities obtained by measuring under the same conditions using 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the respective compounds. Using this calibration curve, the elution amount of the acid generator [B] was calculated from the peak intensity. And the nitrogen compound [C] elution amount was calculated. And the case where the sum total of the elution amount containing an acid generator [B] and a nitrogen-containing compound [C] was 5.0 × 10 ⁻¹² mol / (cm ² · sec) or more was regarded as “bad”. The case where it was the following was defined as “good”.

[LC conditions]
Column: 1 “CAPCELL PAK MG” (manufactured by Shiseido Co., Ltd.) Flow rate: 0.2 ml / min Eluent: Water / methanol (3/7) with 0.1% formic acid Column temperature: 35 ° C.

(2) Formation and evaluation of resist pattern By the following method, a substrate with a photoresist coating formed by sequentially laminating a lower antireflection film and a photoresist coating on the surface of a silicon substrate is formed, and a positive resist pattern is formed. Then, the sensitivity and the cross-sectional shape of the pattern were evaluated.
Using a coater and developer device “CLEAN TRACK ACT12” manufactured by Tokyo Electron Co., Ltd., a lower antireflection film 22 (“ARC29A”, manufactured by Brewer Science Co., Ltd.) having a film thickness of 77 nm is formed on the surface of the 12-inch silicon plate 21 for reflection. A wafer with a protective film (hereinafter referred to as “composite substrate”) was obtained.
Thereafter, the radiation sensitive resin composition prepared above was spin-coated (rotary coated) on the surface of the composite substrate using the “CLEAN TRACK ACT12”, and the coating film was pretreated under the conditions shown in Table 2. By application baking (PAB), an unexposed photoresist film 23 (film thickness 150 nm) was formed, and a substrate 2 with a photoresist film was obtained (see FIG. 2).
Next, with respect to the surface of the photoresist film 23, NA (numerical aperture) 0.75, sigma 0,..., Using a Nikon ArF excimer laser exposure apparatus “NSR S306C” through a photomask having a mask pattern. The exposure was performed under the proof condition of 93 / 0.69. Thereafter, post-exposure heating (PEB) was performed under the conditions shown in Table 2. Then, development was performed at 23 ° C. for 30 seconds with an aqueous tetramethylammonium hydroxide solution having a concentration of 2.38%, followed by washing with water and drying to form a positive resist pattern. At this time, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 90 nm with a one-to-one line width was taken as the optimum exposure amount, and this optimum exposure amount was taken as the sensitivity. In this measurement, a scanning electron microscope (model “S-9380”, manufactured by Hitachi High-Technologies Corporation) was used.
The cross-sectional shape of the 90 nm line and space pattern was observed with an ultra-high resolution field emission scanning electron microscope (model “S-4800”, manufactured by Hitachi High-Technologies Corporation), and as shown in FIG. The line width Lb in the middle of the resist pattern and the line width La at the top of the film are measured, and the range of 0.9 ≦ (La−Lb) /Lb≦1.1 is set to “◯”, and the others are “×”. ".

  As is apparent from Table 2, according to Examples 1 to 3, it was found that the amount of the eluate in the ultrapure water contacted before immersion exposure was small, and the resulting pattern shape was good.

In an Example, it is a schematic sectional drawing which shows the structure for elution amount evaluation for measuring the quantity of an elution thing. It is a schematic sectional drawing which shows a board | substrate with a photoresist film. It is a schematic diagram explaining the cross-sectional shape of a resist pattern.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Structure for elution amount evaluation, 2; Substrate with a photoresist coating (laminated substrate), 21; Silicon plate (substrate), 22; Lower antireflection film, 23; Photoresist coating, 3; Wafer, 31; 32; HMDS treatment layer, 4; silicon rubber sheet, 5; ultrapure water filling part, 6; lower antireflection film, 7; resist pattern.

Claims (5)

A photoresist film forming step of applying a radiation sensitive resin composition on a substrate and forming a photoresist film;
Performing a pre-application bake on the photoresist coating;
A step of performing immersion exposure in which a liquid for immersion exposure having a refractive index higher than that of air at a wavelength of 193 nm is interposed between the lens and the photoresist film, and the photoresist film is irradiated with radiation;
Performing a post-exposure bake on the photoresist coating;
A development step of removing an exposed portion of the photoresist film with a developer, and a resist pattern forming method comprising:
The radiation-sensitive resin composition used for forming the photoresist coating contains a resin having a glass transition temperature of 70 to 150 ° C., a radiation-sensitive acid generator, a nitrogen-containing compound, and a solvent.
Resist pattern, characterized in that the have line pre application bake at a temperature above the glass transition temperature of the resin, and the temperature difference between the glass transition temperature of said resin of the pre-application bake and 5 to 50 ° C. Forming method.   The resist pattern forming method according to claim 1, wherein the resin has a glass transition temperature of 80 to 150 ° C.   The resist pattern forming method according to claim 1, wherein the resin includes a repeating unit having a structure that exhibits alkali solubility by the action of an acid and a repeating unit having a lactone structure.   The resist pattern forming method according to claim 1, wherein in the step of performing the immersion exposure, the exposure is performed in a state where an immersion exposure liquid is disposed on the surface of the photoresist film. A photoresist film forming step of applying a radiation sensitive resin composition on a substrate and forming a photoresist film;
Performing a pre-application bake on the photoresist coating;
A step of performing immersion exposure in which a liquid for immersion exposure having a refractive index higher than that of air at a wavelength of 193 nm is interposed between the lens and the photoresist film, and the photoresist film is irradiated with radiation;
Performing a post-exposure bake on the photoresist coating;
A development step of removing an exposed portion of the photoresist film with a developer, a resist pattern forming method, wherein the radiation-sensitive resin composition used for forming the photoresist film,
A resin having a glass transition temperature of 70 to 150 ° C., a radiation-sensitive acid generator, a nitrogen-containing compound, and a solvent;
Wherein the glass transition temperature of the resin is, the Ri der temperature below when performing pre-application bake, and the temperature difference between the glass transition temperature of said resin of the pre-application bake is 5 to 50 ° C. A radiation sensitive resin composition.

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