JP5481768B2 - Radiation sensitive resin composition and resist pattern forming method using the same - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition suitably used for immersion exposure in which a photoresist film is exposed through a liquid for immersion exposure such as water, and a resist pattern forming method using the same.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, lithography technology 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. However, with such near ultraviolet rays, it is extremely difficult to perform fine processing at a subquarter micron level. Therefore, in order to enable microfabrication at a level of 0.1 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. Among these, KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm) is particularly attracting attention.

  As a resist suitable for excimer laser irradiation, chemical amplification by a component having an acid-dissociable functional group and a component that generates acid upon irradiation (hereinafter referred to as “exposure”) (hereinafter referred to as “acid generator”) Many resists utilizing the 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 t-butyl ester group of carboxylic acid or a t-butyl carbonate group of phenol and an acid generator has been proposed. In this resist, the t-butyl ester group or t-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 (carboxyl group or phenolic hydroxyl group). It will be like that. Therefore, the phenomenon that the exposed region of the resist film becomes readily soluble in an alkali developer is utilized.

  In such a lithography process, formation of a finer pattern (for example, a fine resist pattern having a line width of about 45 nm) will be required in the future. In order to achieve such a pattern formation finer than 45 nm, it is conceivable to shorten the light source wavelength of the exposure apparatus or increase the numerical aperture (NA) of the lens. 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.

  In recent years, an immersion exposure (liquid immersion lithography) method has been reported as a lithography technique capable of solving such problems. In this immersion exposure method, at the time of exposure, a liquid refractive index medium (for immersion exposure) such as pure water or fluorine-based inert liquid having a predetermined thickness is formed on at least the resist film between the lens and the resist film on the substrate. Liquid). 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 an immersion exposure method is adopted, it is possible to realize formation of a resist pattern that is low in cost, excellent in high resolution, and excellent in depth of focus by using a lens mounted on an existing apparatus. Therefore, it is attracting a lot of attention.

  However, in the immersion exposure method, the resist film comes into direct contact with an immersion exposure liquid such as water during exposure, so that the acid generator and the like are eluted from the resist film. When the amount of the eluted material is large, there are problems that the lens is damaged, a predetermined pattern shape cannot be obtained, and sufficient resolution may be difficult to obtain.

  Further, when water is used as the liquid for immersion exposure, there is a problem that if the receding contact angle of water in the resist film is low, the water drop is reduced during high-speed scanning exposure, and the watermark tends to remain.

  As a resist resin used in the immersion exposure apparatus, for example, resins described in Patent Document 1 and Patent Document 2 have been proposed. Moreover, the additive of patent document 3 is also proposed as an additive for resists used for an immersion exposure apparatus. However, even with resists using these resins and additives, the receding contact angle between the resist film and water is not always sufficient. In addition, when the receding contact angle is low, water breakage is reduced during high-speed scanning exposure, and the watermark tends to remain. Furthermore, it cannot be said that the amount of the eluate in water such as an acid generator is sufficiently suppressed.

International Publication No. 2004/068242 Pamphlet JP 2005-173474 A JP 2006-48029 A

  The present invention has been made in view of the above-described problems of the prior art, and the problem is that the amount of the eluate in the immersion exposure liquid that comes into contact with the immersion exposure is small, and the liquid An object of the present invention is to provide a radiation-sensitive resin composition capable of forming a photoresist film having a large receding contact angle with an immersion exposure liquid and capable of forming a fine resist pattern with high accuracy. A further object of the present invention is to provide a resist pattern forming method capable of forming a fine resist pattern with high accuracy.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have determined that when a photoresist film is formed, the fluorine content and the carbon content in a predetermined region from the film surface of the formed photoresist film. It has been found that the above-mentioned problems can be achieved by using a radiation-sensitive resin composition having a ratio within a predetermined numerical range, and the present invention has been completed.

  That is, according to this invention, the radiation sensitive resin composition shown below and the resist pattern formation method using the same are provided.

（前記一般式（９）中、Ｒ^１６は水素、メチル基、又はトリフルオロメチル基を示し、Ｚは単結合、酸素原子、硫黄原子、カルボニルオキシ基、オキシカルボニル基、アミド基、スルホニルアミド基、又はウレタン基を示す。Ｒ^１７は、少なくとも一以上のフッ素原子を含有する、炭素数１〜６の直鎖状若しくは分岐状のアルキル基、又は炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体を示す。）

（前記一般式（Ａ−２）中、Ｒは水素原子又はメトキシメチル基を示す。但し、一般式（Ａ−２）中の全Ｒの４０％がメトキシメチル基である。）

[1] Resin (A) that becomes alkali-soluble by the action of an acid (excluding those having a fluorine atom), a radiation-sensitive acid generator (B), a nitrogen-containing compound (C), a solvent (D), and The fluorine-containing compound (E) is contained, and the amount of the fluorine-containing compound (E) is 0.1 to 40 parts by mass with respect to 100 parts by mass of the resin (A). ) Is a fluorine-containing polymer (E1) containing a repeating unit represented by the following general formula (9) (excluding the repeating units represented by the following formulas (E-1) to (E-27)). Resist pattern formation including an immersion exposure step of exposing a photoresist film formed on a substrate by irradiating with radiation in a state where an immersion exposure liquid having a refractive index higher than that of air is present at a wavelength of 193 nm In the method, the photo register A radiation-sensitive resin composition used to form the bets film, in the case of forming the photoresist film, is measured and calculated by the following surface elemental analysis, the fluorine content of the photoresist film (F ₁ (atom%)) and the carbon content (C ₁ (atom%)) are (F ₁ ) / (C ₁ ) = 0.01 to 0.6, and the ratio of the formed photoresist film is The ratio of fluorine content (F ₂ (atom%)) to carbon content (C ₂ (atom%)) in the whole is (F ₂ ) / (C ₂ ) = 0.004 to 0.05. Radiation sensitive resin composition (however, a resin comprising a repeating unit represented by the following formula (A-1) and a repeating unit represented by the following general formula (A-2), represented by the following formula (A-1) Repeating unit represented by the following formula (A-3) A resin comprising a repeating unit represented by the following formula (A-1) and a repeating unit represented by the following formula (A-4), a repeating unit represented by the following formula (A-5) and the following: Resin comprising a repeating unit represented by the formula (A-6), a resin comprising a repeating unit represented by the following formula (A-5) and a repeating unit represented by the following formula (A-7), A resin comprising a repeating unit represented by A-5) and a repeating unit represented by the following formula (A-8), a repeating unit represented by the following formula (A-5) and the following formula (A-9) Resin comprising a repeating unit represented by the formula, a resin comprising a repeating unit represented by the following formula (A-5) and a repeating unit represented by the following formula (A-10), or represented by the following formula (A-5) And a resin comprising a repeating unit represented by the following formula (A-11) Except those containing. ).
(Surface elemental analysis): A photoelectron spectrometer is used to irradiate the film surface of the photoresist film with an X-ray, and the amount of secondary electrons generated is measured at an angle of 90 ° with respect to the film surface. The distribution amounts of fluorine atoms and carbon atoms in the photoresist film are measured.

(In the general formula (9), R ¹⁶ represents hydrogen, methyl group, or trifluoromethyl group, and Z represents a single bond, oxygen atom, sulfur atom, carbonyloxy group, oxycarbonyl group, amide group, sulfonylamide group. or .R ¹⁷ showing the urethane groups contain at least one or more fluorine atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, or a monovalent alicyclic having 4 to 20 carbon atoms Represents a hydrocarbon group or a derivative thereof.)

(In the general formula (A-2), R represents a hydrogen atom or a methoxymethyl group. However, 40% of all R in the general formula (A-2) is a methoxymethyl group.)

[ 2 ] The resin (A) contains at least one repeating unit (1) having a structure in which alkali solubility is expressed by the action of an acid and a repeating unit (2) having a lactone structure, and is insoluble in alkali or The radiation sensitive resin composition according to the above [ 1 ], which is hardly soluble.

[ 3 ] A photoresist film made of the radiation-sensitive resin composition according to [1] or [2] is formed on the surface of the substrate, and a refractive index at a wavelength of 193 nm is higher on the film surface than air. A resist pattern forming method including an immersion exposure step of exposing the photoresist film by irradiating radiation with the immersion exposure liquid directly in contact.

[4] on the film surface of the photoresist film, the immersion exposure liquid, in a state of being in direct contact mediated without forming a protective film, wherein the [3 which irradiates radiation to the photoresist film ] The resist pattern formation method of description.

  The radiation-sensitive resin composition of the present invention has a fine resist pattern that has a small amount of eluate to the liquid for immersion exposure that comes into contact with liquid immersion exposure and has a large receding contact angle with the liquid for liquid immersion exposure. The effect is that a photoresist film that can be formed with high accuracy can be formed.

  Moreover, according to the resist pattern forming method of the present invention, a fine resist pattern can be formed with high accuracy.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

1. Radiation sensitive resin composition:
One embodiment of the radiation-sensitive resin composition of the present invention irradiates a photoresist film formed on a substrate with radiation in a state where an immersion exposure liquid having a refractive index higher than that of air is interposed at a wavelength of 193 nm. It is a radiation sensitive resin composition used for forming a photoresist film in a resist pattern forming method including an immersion exposure process in which exposure is performed. And when this photoresist film is formed, this radiation sensitive resin composition is measured and calculated by the following surface elemental analysis, and the fluorine content (F ₁ (atom%)) and carbon content of the photoresist film. The ratio to (C ₁ (atom%)) is (F ₁ ) / (C ₁ ) = 0.005 to 0.6, and the fluorine content (F ₂ (F ₂ ( atom%)) and the carbon content (C ₂ (atom%)) are (F ₂ ) / (C ₂ ) = 0.004 to 0.05 (provided that the above formula (A -1) and a resin composed of a repeating unit represented by the above general formula (A-2), a repeating unit represented by the above formula (A-1) and the above formula (A-3) Resin comprising a repeating unit represented by the above formula (A-1) Resin comprising a repeating unit and a repeating unit represented by the above formula (A-4), a resin comprising a repeating unit represented by the above formula (A-5) and a repeating unit represented by the above formula (A-6) A resin comprising a repeating unit represented by the above formula (A-5) and a repeating unit represented by the above formula (A-7), a repeating unit represented by the above formula (A-5) and the above formula (A) -8) resin composed of a repeating unit, a resin composed of a repeating unit represented by the above formula (A-5) and a repeating unit represented by the above formula (A-9), the above formula (A-5) ) And a repeating unit represented by the above formula (A-10) or a repeating unit represented by the above formula (A-5) and the above formula (A-11). Except those containing a resin composed of repeating units) . The details will be described below.
(Surface elemental analysis): Photoresist film is irradiated with X-rays using a photoelectron spectrometer, and the amount of secondary electrons generated is measured at an angle of 90 ° to the film surface. Each distribution amount of fluorine atoms and carbon atoms in the film is measured.

When the radiation sensitive resin composition of this embodiment is applied on a predetermined substrate, a so-called photoresist film can be formed. Here, the photoresist film formed using the radiation-sensitive resin composition of this embodiment has a fluorine content (F ₁ (atom%)) measured and calculated by a specific surface element analysis (ESCA). The ratio with the carbon content (C ₁ (atom%)) falls within a predetermined numerical range. In other words, the photoresist film formed using the radiation-sensitive resin composition of the present embodiment is a region having a predetermined thickness from the film surface (surface (surface) opposite to the substrate to be coated). The fluorine content in is higher than in other regions. For this reason, when a photoresist film is formed using the radiation-sensitive resin composition of the present embodiment and immersion exposure is performed, ordinary components contained in the composition (for example, a radiation-sensitive acid generator or Elution of the acid diffusion control agent or the like into the liquid for immersion exposure is effectively suppressed. Furthermore, due to the water-repellent characteristics of this fluorine, the receding contact angle between the photoresist film and the immersion exposure liquid is increased, so that water droplets hardly remain, and high-speed scanning exposure is possible. Further, not only the elution of components contained in the composition is reduced, but also the resist has high water repellency and can effectively suppress the occurrence of defects derived from immersion exposure liquids such as watermarks.

Fluorine content (F ₁ (atom%)) and carbon content (C ₁ ) measured and calculated by the surface element analysis of the photoresist film formed using the radiation-sensitive resin composition of this embodiment. The ratio (= (F ₁ ) / (C ₁ )) to (atom%)) is 0.01 to 0.6, preferably 0.015 to 0.55. When the value of (F ₁ ) / (C ₁ ) is less than 0.01, the receding contact angle of the photoresist film tends to decrease, or elution of an acid generator or the like from the photoresist film tends to be difficult to suppress. is there. On the other hand, if the value of (F ₁ ) / (C ₁ ) is more than 0.6, the developability of the resist may be lowered.

Further, the fluorine content (F ₂ (atom%)) and the carbon content (C ₂ (atom%)) in the entire photoresist film formed using the radiation-sensitive resin composition of the present embodiment The ratio (= (F ₂ ) / (C ₂ )) is preferably 0.001 to 0.05, more preferably 0.001 to 0.04, and 0.01 to 0.03. It is particularly preferred. The “fluorine content (F ₂ (atom%)) and carbon content (C ₂ (atom%))” in the entire photoresist film are the structures of various components contained in the radiation-sensitive resin composition, It is a numerical value that is theoretically produced from the blending ratio.

Specifically, the radiation-sensitive resin composition of the present invention includes a resin (A) that becomes alkali-soluble by the action of an acid (excluding those having a fluorine atom) , a radiation-sensitive acid generator (B), nitrogen-containing compound (C), a solvent (D), and Ru der those containing a fluorine-containing compound (E). However, a resin comprising a repeating unit represented by the above formula (A-1) and a repeating unit represented by the above general formula (A-2), a repeating unit represented by the above formula (A-1) and the above formula Resin comprising a repeating unit represented by (A-3), a resin comprising a repeating unit represented by the above formula (A-1) and a repeating unit represented by the above formula (A-4), the above formula (A −5) a resin comprising a repeating unit represented by the above formula (A-6), a repeating unit represented by the above formula (A-5) and the above formula (A-7). A resin composed of a repeating unit represented by the above formula (A-5) and a resin composed of a repeating unit represented by the above formula (A-8), represented by the above formula (A-5). A resin comprising a repeating unit and a repeating unit represented by the above formula (A-9), the above formula (A- ) And a repeating unit represented by the above formula (A-10) or a repeating unit represented by the above formula (A-5) and the above formula (A-11). Except those containing resin consisting of repeating units. Details of each component will be described below.

(Resin (A))
The resin (A) is a resin that becomes alkali-soluble by the action of an acid (excluding those having a fluorine atom) . As the resin (A), it is preferable to use a resin that is insoluble or hardly soluble in alkali and becomes alkali-soluble by the action of an acid. Here, the term “alkali insoluble or hardly soluble” as used herein refers to an alkali that is used when a resist pattern is formed from a photoresist film formed from a radiation-sensitive resin composition containing the resin (A). When a film using only the resin (A) instead of the photoresist film is developed under development conditions, it means that 50% or more of the initial film thickness of the film remains after development.

  Specific examples of the resin (A) include a resin having an alicyclic skeleton such as a norbornane ring in a main chain obtained by polymerizing a norbornene derivative or the like, and a main chain obtained by copolymerizing a norbornene derivative and maleic anhydride. Resin having a norbornane ring and a maleic anhydride derivative, a resin having a norbornane ring and a (meth) acryl skeleton mixed in the main chain obtained by copolymerizing a norbornene derivative and a (meth) acrylic compound, a norbornene derivative, maleic anhydride, and Resin in which norbornane ring, maleic anhydride derivative and (meth) acrylic skeleton are mixed in the main chain obtained by copolymerizing (meth) acrylic compound, and main chain obtained by copolymerizing (meth) acrylic compound is (meta ) Acrylic skeleton resin and the like. “(Meth) acryl” means either or both of “acryl” and “methacryl”. In addition, resin (A) can be used individually by 1 type or in combination of 2 or more types.

  Moreover, it is preferable that resin (A) contains the repeating unit (henceforth "repeating unit (1)") containing group represented by the following general formula (1).

(In the general formula (1), R ¹ is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched chain having 1 to 4 carbon atoms, which are independent of each other. Represents an alkyl group, and at least one of R ^{1 is} an alicyclic hydrocarbon group or a derivative thereof, or any two of R ¹ are bonded to each other, and each is bonded A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof is formed together with a carbon atom, and the remaining R ¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, or the number of carbon atoms 4-20 monovalent alicyclic hydrocarbon groups or derivatives thereof)

In the general formula (1), a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ¹ and any two R ^{1 s} bonded to each other to form 4 to 20 carbon atoms. Examples of the divalent alicyclic hydrocarbon group include fatty acids derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A group consisting of a cyclic ring; a group consisting of these alicyclic rings is, for example, a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methyl Examples thereof include groups substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as propyl group and t-butyl group. Among these alicyclic hydrocarbon groups, a group consisting of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane or cyclohexane, or a group consisting of these alicyclic rings is described above. A group substituted with an alkyl group is preferred.

  Examples of the alicyclic hydrocarbon group derivative include hydroxyl group; carboxyl group; oxo group (that is, ═O group); hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxy. A hydroxyalkyl group having 1 to 4 carbon atoms such as propyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group; C1-C4 alkoxyl groups such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group; cyano group ; C2-C5 shear such as cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl group, etc. It can include one or more or one or more a group having a substituent such as an alkyl group. Of these, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, a cyanomethyl group, and the like are preferable.

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

  As the skeleton contained in the repeating unit (1), for example, a group represented by the following general formula (a), the following general formula (b), the following general formula (c), or the following general formula (d) is preferable.

(In the general formulas (a) to (d), R ² independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, and m represents an integer of 0 to 4).

In the general formulas (a) to (d), examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ² include a methyl group, an ethyl group, an n-propyl group, and i. -Propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group are preferable.

The two R ² in the general formula (a) are preferably both methyl groups. Further, R ² in the general formula (b) is preferably a methyl group, an ethyl group, an n-propyl group, or an i-propyl group. In the general formula (c), m = 0 and R ² = methyl group combination, m = 0 and R ² = ethyl group combination, m = 1 and R ² = methyl group combination, m = 1 and R ² = A combination of ethyl groups is preferred. Moreover, it is preferable that two R < ² > in the said general formula (d) is a methyl group.

  Preferred skeletons contained in the repeating unit (1) other than the general formulas (a) to (d) are, for example, t-butoxycarbonyl groups, represented by the following formulas (e-1) to (e-8). And the like.

The main chain skeleton of the repeating unit (1) is not particularly limited, but is preferably skeleton having methacrylic acid ester structure, or an acrylic acid ester structure. In the present specification, “(meth) acrylic acid ester” indicates both acrylic acid ester and methacrylic acid ester.

As a preferable monomer used for constituting the repeating unit (1), for example, (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-methyl Rishikuro [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-cyclopentyl Examples include esters, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester, and the like.

  Among the above monomers, (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) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (Meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl 1-cyclohexyl ester are more preferred. In addition, 2 or more types of repeating units (1) may be contained in resin (A).

  Further, the resin (A) includes a repeating unit (2) containing groups represented by the following general formulas (2-1) to (2-6) (hereinafter also referred to as “repeating unit (2)”). It is preferable.

(In the general formula (2-1) ~ (2-6), R 3 represents an alkyl group which may have a hydrogen atom or a substituent having 1 to 4 carbon atoms, ^{R 4} is a hydrogen atom or a methoxy group A represents a single bond or a methylene group, B represents an oxygen atom or a methylene group, l represents an integer of 1 to 3, and m represents 0 or 1.

The main chain skeleton of the repeating unit (2) is not particularly limited, but is preferably skeleton having methacrylic acid ester structure, or an acrylic acid ester structure.

As a preferable monomer used for constituting the repeating unit (2), for example, (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nona- 2-yl ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid -5-oxo-4-oxatricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxatri Cyclo [5.2.1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, ( (Meth) acrylic acid-4-methoxyca Bonyl-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-oxabicyclo [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-oxotetrahydropyran-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-2-ylmethyl ester, (meth) acrylic acid- , May be mentioned 4-dimethyl-5-oxo-tetrahydrofuran-2-yl methyl ester. Two or more types of repeating units (2) may be contained in the resin (A).

Furthermore, the resin (A) may contain a repeating unit other than the repeating unit (1) and the repeating unit (2) (hereinafter also referred to as “other repeating unit”). As other repeating units, the repeating unit represented by the following general formula (3) (hereinafter, also referred to as "repeating unit (3)"), the repeating units (hereinafter represented by the following following general formula (5), " At least one selected from the group consisting of (also referred to as repeating unit (5)) is preferred.

In the general formula (3), R ⁵ represents a hydrogen atom or a methyl group, and X represents a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. The polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms may be substituted with an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a cyano group, or a hydroxyalkyl group having 1 to 10 carbon atoms.

In the general formula (5), R ⁸ represents hydrogen or a methyl group, X represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Y independently of each other represents a single bond or a carbon number. 1 to 3 divalent organic groups, and R9 independently represents a hydrogen atom, a hydroxyl group, a cyano group, or a COOR ¹⁰ group. However, R ¹⁰ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl group having 3 to 20 carbon atoms. When at least one of the three R ⁹ is not a hydrogen atom and X is a single bond, at least one of the three Y is a divalent organic group having 1 to 3 carbon atoms. Preferably there is.

X in the repeating unit (3) represented by the general formula (3) is preferably a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. Examples of such polycyclic alicyclic hydrocarbon groups include bicyclo [2.2.1] heptane (3a) and bicyclo [2.2.2, as shown in the following formulas (3a) to (3e). 2] Octane (3b), tricyclo [5.2.1.0 ^2,6 ] decane (3c), tetracyclo [6.2.1.1 ^3,6 . And hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as 0 ^2,7 ] dodecane (3d) and tricyclo [3.3.1.1 ^3,7 ] decane (3e).

  These cycloalkane-derived alicyclic rings may have a substituent. Examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, and a t-butyl group. One or more or four or more linear, branched or cyclic alkyl groups may be mentioned. In addition, cycloalkane-derived alicyclic rings are not limited to those substituted by these alkyl groups, but are hydroxyl groups, cyano groups, hydroxyalkyl groups having 1 to 10 carbon atoms, carboxyl groups, and oxygen. It may be substituted. Two or more types of repeating units (3) may be contained in the resin (A).

Preferred monomers used for constituting the repeating unit (3) include, for example, (meth) acrylic acid-bicyclo [2.2.1] heptyl ester, (meth) acrylic acid-cyclohexyl ester, (meth) Acrylic acid-bicyclo [4.4.0] decanyl ester, (meth) acrylic acid-bicyclo [2.2.2] octyl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] Decanyl ester, (meth) acrylic acid-tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] decanyl ester, and the like.

Examples of the divalent organic group having 1 to 3 carbon atoms represented by X and Y in the repeating unit (5) represented by the general formula (5) include a methylene group, an ethylene group, and a propylene group. it can. In addition, among R ^{9 in} the general formula (5), examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ^{10 in} the group represented by —COOR ¹⁰ include, for example, a methyl group , Ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group and t-butyl group. Examples of the alicyclic alkyl group having 3 to 20 carbon _{atoms, -C n H 2n-1 (} n is an integer of 3-20) cycloalkyl group represented by (e.g., cyclopropyl group, cyclobutyl group, Cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, etc.). In addition, examples of the polycyclic alicyclic alkyl group include a bicyclo [2.2.1] heptyl group, a tricyclo [5.2.1.0 ^2,6 ] decyl group, and a tetracyclo [6.2.1 ^3,6. . 0 ^2,7 ] dodecanyl group, adamantyl group or the like, or one or more of linear, branched, or cyclic alkyl groups, and a part of cycloalkyl group or polycyclic alicyclic alkyl group. Examples include substituted groups.

  Preferable monomers used for constituting the repeating unit (5) include, for example, (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 Examples thereof include 3-hydroxy-5,7-dimethyladamantan-1-yl ester and (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-ylmethyl ester.

Resin (A) contains a repeating unit in which a polymerizable unsaturated bond of a polyfunctional monomer shown below is cleaved as a repeating unit other than the above repeating units (1) to ( 3 ) and (5). It may be.

  (Meth) acrylic acid esters having a bridged hydrocarbon skeleton such as (meth) acrylic acid dicyclopentenyl, (meth) acrylic acid adamantylmethyl; (meth) acrylic acid carboxynorbornyl, (meth) acrylic acid carboxy Carboxyl group-containing esters having a bridged hydrocarbon skeleton of an unsaturated carboxylic acid such as tricyclodecanyl or carboxytetracycloundecanyl (meth) acrylate;

  Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 1-methyl (meth) acrylate Propyl, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, ( (Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 4-methoxycyclohexyl, (meth) acrylic acid 2-cyclopentyloxycarbonylethyl, (meth) acrylic acid 2-cyclohexyloxycarbonylethyl, (meth) 2- (4-Methoxycyclohexyl) acrylic acid No bridged hydrocarbon skeleton such as aryloxycarbonyl ethyl (meth) acrylate;

  α-hydroxymethyl acrylate esters such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate; (meth) acrylonitrile , Α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesaconitrile, citraconitrile, itaconnitrile, and other unsaturated nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide , Fumaramide, mesaconamide, citraconic amide, itaconic amide, etc .; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinyl Other nitrogen-containing vinyl compounds such as lysine and vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, etc. Unsaturated carboxylic acids (anhydrides); 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, Carboxyl group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as (meth) acrylic acid 4-carboxycyclohexyl;

  1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, etc. A polyfunctional monomer having a bridged hydrocarbon skeleton;

  Styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2-t-butoxycarbonylethyloxy) styrene 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene, 2-hydroxy-α-methylstyrene, 3-hydroxy-α-methylstyrene, 4-hydroxy-α-methylstyrene, 2-methyl-3-hydroxystyrene 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene, 2,4,6- Trihydroxystyrene, 4-t-butoxystyrene, 4-t Butoxy-α-methylstyrene, 4- (2-ethyl-2-propoxy) styrene, 4- (2-ethyl-2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- ( 1-ethoxyethoxy) -α-methylstyrene, phenyl (meth) acrylate, benzyl (meth) acrylate, acenaphthylene, 5-hydroxyacenaphthylene, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-hydroxy-6 Vinylnaphthalene, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, 1-naphthylmethyl (meth) acrylate, 1-anthryl (meth) acrylate, 2-anthryl (meth) acrylate, 9-anthryl (meth) Acrylate, 9-anthrylmethyl (meth) acrylate, 1-vinyl A monomer having an aromatic skeleton such as lupine;

  Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 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, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate, 1,3-bis A polyfunctional monomer having no bridged hydrocarbon skeleton such as (2-hydroxypropyl) benzenedi (meth) acrylate;

  Of the repeating units composed of these polyfunctional monomers, units in which a polymerizable unsaturated bond of a (meth) acrylic acid ester having a bridged hydrocarbon skeleton is cleaved are preferred.

  The ratio of the repeating unit (1) contained in the resin (A) is usually 10 to 90 mol%, preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on all repeating units. If the content of the repeating unit (1) is less than 10 mol%, the resolution as a resist tends to deteriorate. On the other hand, if it exceeds 90 mol%, the developability of the resist tends to deteriorate.

  The ratio of the repeating unit (2) contained in the resin (A) is usually 10 to 70 mol%, preferably 15 to 65 mol%, more preferably 20 to 60 mol%, based on all repeating units. When the content ratio of the repeating unit (2) is less than 10 mol%, the resist tends to be reduced in solubility in an alkaline developer, which tends to contribute to development defects and to deteriorate the exposure margin. is there. Here, the exposure margin means a change in line width with respect to a change in exposure amount. On the other hand, if it exceeds 70 mol%, the solubility of the resist in the solvent tends to be low, and the resolution tends to decrease.

  The ratio of the repeating unit (3) contained in the resin (A) is usually 30 mol% or less, preferably 25 mol% or less, based on all repeating units. When the content ratio of the repeating unit (3) is more than 30 mol%, the resulting photoresist film tends to swell with the alkali developer or the solubility in the alkali developer tends to decrease.

  Moreover, the ratio of the repeating unit (5) contained in resin (A) is 30 mol% or less normally with respect to all the repeating units, Preferably it is 25 mol% or less. When the content ratio of the repeating unit (5) is more than 30 mol%, the resulting photoresist film tends to swell with an alkali developer or the solubility in an alkali developer tends to be reduced.

  Resin (A) uses, for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit, and radical polymerization initiators such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. And it can manufacture by superposing | polymerizing in a suitable solvent in presence of a chain transfer agent as needed.

  Examples of the solvent used for polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, norbornane. Cycloalkanes such as benzene, toluene, xylene, ethylbenzene, cumene and other aromatic hydrocarbons; chlorobutanes, bromohexanes, dichloroethanes, halogenated hydrocarbons such as hexamethylene dibromide, chlorobenzene; ethyl acetate, Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, di List ethers such as ethoxyethanes Rukoto can. These solvents can be used alone or in combination of two or more. The reaction temperature in 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.

  The weight average molecular weight (Mw) in terms of polystyrene by the gel permeation chromatography (GPC) method of the resin (A) is preferably 1,000 to 100,000, more preferably 1,000 to 30,000, and particularly preferably 1, 000 to 20,000. If the Mw of the resin (A) is less than 1,000, the heat resistance of the photoresist film tends to decrease. On the other hand, if the Mw of the resin (A) is more than 100,000, the developability of the photoresist film tends to be lowered. In addition, ratio (Mw / Mn) of Mw of resin (A) and polystyrene number average molecular weight (Mn) by GPC method becomes like this. Preferably it is 1-5, More preferably, it is 1-3.

  The ratio of the low molecular weight component derived from the monomer used when preparing the resin (A) contained in the resin (A) (in terms of solid content) is 100% by mass of the resin (A). The content is preferably 0.1% by mass or less, more preferably 0.07% by mass or less, and particularly preferably 0.05% by mass or less. When the content ratio of the low molecular weight component is 0.1% by mass or less, it is possible to further reduce the amount of the eluate in the immersion exposure liquid such as water that has been in contact with the immersion exposure. Furthermore, it is difficult for foreign matters to be generated during storage of the radiation-sensitive resin composition, and uneven coating is difficult to occur even when applied to a substrate or the like, and the occurrence of defects during resist pattern formation can be sufficiently suppressed. .

  In addition, as a low molecular weight component originating in a monomer, Mw = 500 or less components, such as a monomer, a dimer, a trimer, and an oligomer, can be mentioned. Such low molecular weight components should be removed, for example, by chemical purification methods such as washing with water, liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. Can do. Moreover, the content rate of these low molecular weight components can be measured by analyzing resin (A) by a high performance liquid chromatography (HPLC). In addition, resin (A) is so preferable that there is little content of impurities, such as a halogen and a metal, and, thereby, the sensitivity at the time of setting it as a radiation sensitive resin composition, resolution, process stability, a pattern shape, etc. are improved further. be able to.

(Radiosensitive acid generator (B))
The radiation sensitive acid generator (B) is a component that generates an acid upon irradiation (exposure) of radiation, and dissociates an acid dissociable group existing in the copolymer by the action of the generated acid (protecting group). Desorption). As a result, the exposed portion of the photoresist film becomes readily soluble in an alkali developer, and a positive resist pattern can be formed. As a radiation sensitive acid generator contained in the radiation sensitive resin composition of this invention, what contains the compound represented by following General formula (6) is preferable.

In the general formula (6), R ¹¹ is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched group having 1 to 10 carbon atoms. An alkoxyl group or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms is shown. R ¹² represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. R ¹³ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group, or an optionally substituted naphthyl group. However, two R < ¹³ > may combine with each other to form a divalent group having 2 to 10 carbon atoms, and the divalent group may be substituted. k is an integer of 0 to 2, and X ⁻ is a formula: R ¹⁴ C _n F _2n SO ₃ ⁻ (wherein R ¹⁴ is a fluorine atom or an optionally substituted hydrocarbon having 1 to 12 carbon atoms. An anion represented by the formula: R ¹⁴ SO ₃ ^— , or the following general formulas (7-1) and (7-2): R represents an integer of 0 to 10.

In the general formulas (7-1) and (7-2), R ¹⁵ independently represents an alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms. However, two R ¹⁵ are bonded to each other to form a group containing a divalent fluorine atom having 2 to 10 carbon atoms, and the divalent group may be substituted.

Examples of the linear or branched alkyl group having 1 to 10 carbon atoms of R ¹¹ , R ¹² and R ¹³ in the general formula (6) include, for example, a methyl group, an ethyl group, an 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, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group and the like can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

Examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms of R ¹¹ and R ¹² in the general formula (6) include a methoxy group, an ethoxy group, an n-propoxy group, and an i-propoxy group. N-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy Group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group and the like. Of these alkoxyl groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

Examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms of R ¹¹ in the general formula (6) include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, and i-propoxy group. Carbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n -Heptyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like can be mentioned. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms in R ¹² in the general formula (6) include a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, n-butanesulfonyl group, tert-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n-nonane Examples include a sulfonyl group, an n-decanesulfonyl group, a cyclopentanesulfonyl group, and a cyclohexanesulfonyl group. Of these alkanesulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable. Moreover, as r in the said General formula (6), 0-2 are preferable.

Examples of the optionally substituted phenyl group represented by R ¹³ in the general formula (6) include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 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, Phenyl group such as 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group; substituted with a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms A phenyl group substituted with these phenyl group or alkyl group, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxy group; Examples include a group substituted with at least one group such as a sialkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group.

  Of the substituents that can be introduced into a phenyl group and a phenyl group substituted with an alkyl group, the alkoxyl group includes, for example, a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, Examples thereof include linear, branched or cyclic alkoxyl groups having 1 to 20 carbon atoms such as 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, cyclopentyloxy group, cyclohexyloxy group and the like. it can.

  Of the substituents that can be introduced into a phenyl group and a phenyl group substituted with an alkyl group, examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, Examples thereof include linear, branched, or cyclic alkoxyalkyl groups having 2 to 21 carbon atoms such as 1-ethoxyethyl group and 2-ethoxyethyl group. Among the substituents that can be introduced into a phenyl group substituted with a phenyl group or an alkyl group, examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, and an i-propoxycarbonyl group. A linear or branched group having 2 to 21 carbon atoms such as a group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl, etc. And cyclic alkoxycarbonyl groups and the like.

Among the substituents that can be introduced into a phenyl group and a phenyl group substituted with an alkyl group, the alkoxycarbonyloxy group includes, for example, a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, Linear, branched or cyclic alkoxycarbonyl having 2 to 21 carbon atoms such as i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl, etc. An oxy group etc. can be mentioned. In the general formula (6), as the optionally substituted phenyl group for R ¹³ , phenyl group, 4-cyclohexylphenyl group, 4-t-butylphenyl group, 4-methoxyphenyl group, 4-t-butoxy A phenyl group and the like are preferable.

Examples of the optionally substituted naphthyl group of R ¹³ in the general formula (6) include 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-naphthyl 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-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group, 2-naphthyl group, 1-methyl Substituted with a naphthyl group such as a 2-naphthyl group, 3-methyl-2-naphthyl group, 4-methyl-2-naphthyl group, or a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms These naphthyl groups or alkyl-substituted naphthyl groups are substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Examples include substituted groups.

  Examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group, and alkoxycarbonyloxy group as the above-described substituent include the groups exemplified for the above-described phenyl group and alkyl-substituted phenyl group.

In the general formula (6), as the optionally substituted naphthyl group of R ¹³ , 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-propoxynaphthyl) group ) Group, 2- (7-n-butoxynaphthyl) group and the like are preferable.

The divalent group having 2 to 10 carbon atoms formed by bonding two R ¹³ to each other, together with the sulfur atom in the general formula (6), is a 5-membered or 6-membered ring, particularly preferably a 5-membered ring. Groups that form a ring (ie, a tetrahydrothiophene ring) are desirable. Examples of the substituent that can be introduced into the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxy group exemplified as the substituents for the above-described phenyl group and alkyl-substituted phenyl group. Examples thereof include an alkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. As R ¹³ 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 ^13s are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom. A divalent group or the like that forms is preferable.

  Preferred cation sites of the general formula (6) include triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, and 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, 1- ( -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-propoxy) Naphthyl) tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation, 2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthyl) tetra Mud thiophenium cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) can be exemplified tetrahydrothiophenium cation, or the like.

In the general formula (6), the C _n F _2n — group in the R ¹⁴ C _n F _2n SO ₃ ^— anion represented by X ⁻ is a perfluoroalkylene group having n carbon atoms. The alkylene group may be linear or branched. Here, n is preferably 1, 2, 4, or 8. Examples of the optionally substituted hydrocarbon group having 1 to 12 carbon atoms in R ¹⁴ in R ¹⁴ C _n F _2n SO ₃ ^— and R ¹⁴ SO ₃ ^— anion include an alkyl group having 1 to 12 carbon atoms, cyclo An alkyl group and a bridged alicyclic hydrocarbon group 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.

Examples of the alkyl group containing a linear or branched fluorine atom having 1 to 10 carbon atoms independently of each other of R ¹⁵ in the general formula (7) include a trifluoromethyl group, a pentafluoroethyl group, a hepta. A fluoropropyl group, a nonafluorobutyl group, a dodecafluoropentyl group, a perfluorooctyl group, etc. can be mentioned.

In the general formula (7), two examples of the group containing divalent fluorine atoms bonded to carbon atoms 2 to 10 R ¹⁵ with each other, tetrafluoroethylene group, hexafluoropropylene group, octafluorobutylene Group, decafluoropentylene group, undecafluorohexylene group and the like.

  Preferred anion sites of the general formula (7) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hept-2- Yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, 1-adamantylsulfonate anion, and the following formula ( Examples include the anions represented by 8-1) to (8-7).

  Although the radiation sensitive acid generator (B) is given by the combination of the cation and the anion exemplified above, the combination is not particularly limited. Moreover, a radiation sensitive acid generator (B) can be used individually by 1 type or in combination of 2 or more types.

  Examples of the radiation sensitive acid generator other than the above-mentioned radiation sensitive acid generator (B) include radiation sensitive acid generators such as onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds. (Hereinafter also referred to as “other acid generators”) can be used. Specific examples of these “other acid generators” include the following.

  Onium salt compounds: Examples of the onium salt compounds include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. More specific onium salt compounds 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-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-Butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2 Tetrafluoroethane sulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

  Halogen-containing compound: Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. More specific halogen-containing compounds include phenyltris (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine and the like (trichloro And methyl) -s-triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

  Diazoketone compound: Examples of the diazoketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like. More specific diazo ketone compounds include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2,4 of 4,3,4,4′-tetrahydroxybenzophenone. Naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane or Examples include 1,2-naphthoquinonediazide-5-sulfonic acid ester.

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

  Sulfonic acid compounds: 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. More specific sulfonic acid compounds 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- (trifluoromethanesulfone Ruoxy) 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 imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic imidononafluoro-n-butanesulfonate, 1,8-naphthalenedicarboxylic Examples include acid imido perfluoro-n-octane sulfonate.

  Among the above-mentioned “other acid generators”, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1]. Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium nonafluoro-n-butanesulfonate Bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-Tetra Fluoroethanesulfonate, 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-tetrafluoroethanesulfonate Bicyclo [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-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid Imidotrifluoromethanesulfonate and the like are preferable. These “other acid generators” can be used alone or in combination of two or more.

  The total amount of the radiation-sensitive acid generator (B) and “other acid generator” is usually 0 with respect to 100 parts by mass of the resin (A) from the viewpoint of ensuring the sensitivity and developability as a resist. 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass. If the total amount used is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, if it exceeds 20 parts by mass, the transparency to radiation is lowered, and it tends to be difficult to obtain a rectangular resist pattern. The ratio of the “other acid generator” used is usually 80% by mass or less, preferably 60% by mass, based on the total of the radiation-sensitive acid generator (B) and “other acid generator”. It is as follows.

(Nitrogen-containing compound (C))
The nitrogen-containing compound (C) is an acid diffusion control agent that controls the diffusion phenomenon in the photoresist film of the acid generated from the radiation-sensitive acid generator (B) upon exposure and suppresses undesired chemical reactions in non-exposed areas. It is a component that acts. By blending such an acid diffusion controller, the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and the process from exposure to heat treatment after exposure is improved. A change in the line width of the resist pattern due to a change in the placement time (PED) can be suppressed, and a composition having extremely excellent process stability can be obtained.

  Examples of such acid diffusion control agents include tertiary amine compounds, amide group-containing compounds, quaternary ammonium hydroxide compounds, and other nitrogen-containing heterocyclic compounds.

  Tertiary amine compound: Examples of the tertiary amine compound include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, Tri (cyclo) alkylamines such as tri-n-octylamine, cyclohexyldimethylamine, dicyclohexylmethylamine, tricyclohexylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methyl Aromatic amines such as aniline, 4-methylaniline, 4-nitroaniline, 2,6-dimethylaniline and 2,6-diisopropylaniline; alkanolamines such as triethanolamine and N, N-di (hydroxyethyl) aniline Class; N, N, N ′, N′-teto Methylethylenediamine, 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.

  Amide group-containing compound: Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, N -T-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S )-(−)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4 -Hydroxypiperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxy Carbonyl piperazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4 ′ -Diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N'-di-t-butoxycarbonyl- 1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di -T-butoxycarbonyl-1,10-diaminodecane, N, N'-di-t-butoxycarbonyl-1,12-diaminodode N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl Examples thereof include Nt-butoxycarbonyl group-containing amino compounds such as 2-phenylbenzimidazole.

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

  Nitrogen-containing heterocyclic compound: Examples of the nitrogen-containing heterocyclic compound include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2- Pyridines such as methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine; piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine Others, pyrazine, 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-methyl Imidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole Nt-butoxycarbonyl-2-phenylbenzimidazole and the like. These acid diffusion control agents (nitrogen-containing compounds (C)) can be used singly or in combination of two or more.

  The use amount of the nitrogen-containing compound (C) is usually less than 10 parts by mass, preferably less than 5 parts by mass with respect to 100 parts by mass of the resin (A) from the viewpoint of ensuring high sensitivity as a resist. When the amount of the nitrogen-containing compound (C) used exceeds 10 parts by mass, the sensitivity as a resist tends to be remarkably lowered. When the amount of nitrogen-containing compound used is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist tend to decrease depending on the process conditions.

(Solvent (D))
The radiation-sensitive resin composition of the present embodiment is dissolved in a predetermined solvent (solvent (D)) so that the total solid content is usually 1 to 50% by mass, preferably 1 to 25% by mass. For example, it can be prepared by filtering with a filter having a pore diameter of about 0.2 μm.

  Examples of the solvent (D) include 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, and 3,3-dimethyl. Linear or branched ketones such as 2-butanone, 2-heptanone, 2-octanone; cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone Cyclic ketones such as: propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl ether Propylene glycol monoalkyl ether acetates such as cetate, propylene glycol mono-i-butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; methyl 2-hydroxypropionate, 2-hydroxypropionic acid Ethyl, 2-hydroxypropionate n-propyl, 2-hydroxypropionate i-propyl, 2-hydroxypropionate n-butyl, 2-hydroxypropionate i-butyl, 2-hydroxypropionate sec-butyl, 2-hydroxy Alkyl 2-hydroxypropionates such as t-butyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionate Methyl phosphate, other 3-alkoxy propionic acid alkyl such as ethyl 3-ethoxypropionate,

  n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-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 monoethyl 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, diethylene glycol Cole 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. Can do.

  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. . These solvent (D) can be used individually by 1 type or in combination of 2 or more types.

(Fluorine-containing compound (E))
The fluorine-containing compound (E) is a compound containing fluorine in its molecular structure. The fluorine-containing compound (E) preferably has a receding contact angle with water at the time of forming a film containing the fluorine-containing compound (E) of 70 ° or more, and 75 ° or more. More preferably, it is particularly preferably 80 ° or more, and most preferably 85 ° or more. The “retracting contact angle” in the present specification refers to the liquid surface when 25 μl of water is dropped on the substrate on which the coating film is formed, and then the water on the substrate is sucked at a rate of 10 μl / min. The contact angle with the substrate. This contact angle can be measured using, for example, a contact angle meter (trade name “DSA-10”) manufactured by KRUS, as shown in the following examples.

  This fluorine-containing compound (E) has a site containing fluorine in its molecular structure. Therefore, when added as a component of the radiation-sensitive resin composition, when the photoresist film is formed, its distribution tends to increase on the surface of the photoresist film due to its oil repellency characteristics. For this reason, at the time of immersion exposure, it becomes possible to suppress effectively that a radiation sensitive acid generator, an acid diffusion control agent, etc. elute to the liquid for immersion exposure. Further, due to the water-repellent characteristics of the fluorine-containing compound (E), the receding contact angle between the photoresist film and the immersion exposure liquid becomes high, so that water droplets hardly remain, and high-speed scan exposure is possible. . Further, when used in combination with the conventional liquid immersion upper layer film, not only elution is further reduced, but also the resist has high water repellency and can suppress the occurrence of defects derived from liquid for immersion exposure such as watermark. .

Here, it referred to herein as "fluorine-containing compound (E)" are relatively high molecular weight polymers (hereinafter "fluorine-containing polymer (E1)") Ru der (however, the formula (E1 ) To (E-27) are excluded). Na us, fluorine-containing compound (E) may be used either individually or in combination of two or more.

  The fluorine-containing polymer (E1) can be prepared by polymerizing one or more monomers containing fluorine atoms in the molecular structure. The monomer containing a fluorine atom in its molecular structure includes a monomer containing a fluorine atom in the main chain, a monomer containing a fluorine atom in the side chain, and a single monomer containing a fluorine atom in the main chain and the side chain. The body can be mentioned.

  Examples of the monomer containing a fluorine atom in the main chain include an α-fluoroacrylate compound, an α-trifluoromethyl acrylate compound, a β-fluoroacrylate compound, a β-trifluoromethyl acrylate compound, and an α, β-fluoroacrylate compound. , Α, β-trifluoromethyl acrylate compounds, compounds in which one or more types of vinyl moiety hydrogen is substituted with fluorine or a trifluoromethyl group, and the like.

  Examples of the monomer containing a fluorine atom in the side chain include those in which the side chain of an alicyclic olefin compound such as norbornene is fluorine, a fluoroalkyl group or a derivative thereof; a fluoroalkyl group of acrylic acid or methacrylic acid And ester compounds of derivatives thereof, and those in which the side chain of one or more olefins (sites not containing double bonds) is a fluorine or fluoroalkyl group or a derivative thereof.

  Examples of monomers containing fluorine atoms in the main chain and side chain include α-fluoroacrylic acid, β-fluoroacrylic acid, α, β-fluoroacrylic acid, α-trifluoromethylacrylic acid, β-trifluoro Ester compounds of fluoroalkyl groups such as methylacrylic acid and α, β-trifluoromethylacrylic acid and their derivatives; the side chain of a compound in which one or more types of vinyl moiety hydrogen has been replaced with fluorine or a trifluoromethyl group Substituted with a fluorine or fluoroalkyl group or a derivative thereof; the hydrogen bonded to the double bond of one or more alicyclic olefin compounds is substituted with a fluorine atom or a trifluoromethyl group, and the side chain is Examples thereof include a fluoroalkyl group and derivatives thereof. The alicyclic olefin compound refers to a compound in which a part of the ring is a double bond.

Fluorine-containing polymer (E1) is a repeating unit (hereinafter, also referred to as "repeating unit (6)") represented by the following following general formula (9) Ru der those containing. In addition, a fluorine-containing polymer (E1) may contain only 1 type of this repeating unit (6), and may contain 2 or more types.

In the general formula (9), R ¹⁶ represents hydrogen, a methyl group, or a trifluoromethyl group, Z represents a single bond, an oxygen atom, a sulfur atom, a carbonyloxy group, an oxycarbonyl group, an amide group, a sulfonylamide group, Or a urethane group is shown. R ¹⁷ represents a linear or branched alkyl group having 1 to 6 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing at least one fluorine atom. Show.

The linking group in the general formula (9), represented by Z is a single bond, an oxygen atom, a sulfur atom, a carbonyl group, an oxycarbonyl group, an amide group, sulfonyl amide groups, or a urethane group.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms and containing at least one fluorine atom in R ¹⁷ of the general formula (9) include, for example, a methyl group, an ethyl group, and 1-propyl. Group, 2-propyl group, 1-butyl group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2 -Methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4 -Methylpentyl) group, 3- (2-methylpe) Nyl) group, 3- (3-methylpentyl) group or the like, or a group in which a linear or branched alkyl group is partially fluorinated, or a perfluoroalkyl group.

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing at least one or more fluorine atoms in R ¹⁷ of the general formula (9) include, for example, a cyclopentyl group, a cyclopentylmethyl group, 1- (1-cyclopentylethyl) group, 1- (2-cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group A group in which an alicyclic alkyl group such as cycloheptylmethyl group, 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, and 2-norbornyl group is partially fluorinated, or A perfluoroalkyl group etc. can be mentioned.

  Preferred monomers used for constituting the repeating unit (6) include, for example, trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, and perfluoroethyl. (Meth) acrylic acid ester, perfluoro n-propyl (meth) acrylic acid ester, perfluoro i-propyl (meth) acrylic acid ester, perfluoro n-butyl (meth) acrylic acid ester, perfluoro i-butyl (meta ) Acrylic acid ester, perfluoro t-butyl (meth) acrylic acid ester, 2- (1,1,1,3,3,3-hexafluoropropyl) (meth) acrylic acid ester, 1- (2,2, 3,3,4,4,5,5-octafluoropentyl) (meth) acrylic acid ester, perfluorosilane Rohexylmethyl (meth) acrylic acid ester, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylic acid ester, 1- (3,3,4,4,5,5,6 , 6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl) (meth) acrylic acid ester, 1- (5-trifluoromethyl-3,3,4,4, 5,6,6,6-octafluorohexyl) (meth) acrylic acid ester and the like.

  The ratio of the repeating unit (6) contained in the fluorine-containing polymer (E1) is usually at least 5 mol%, preferably at least 10 mol%, more preferably at least 15 mol%, based on all repeating units. When the content ratio of the repeating unit (6) is less than 5 mol%, it becomes difficult to set the receding contact angle to 70 ° or more, and elution of the radiation sensitive acid generator (B) and the like from the photoresist film. Tends to be difficult to suppress.

  Moreover, it is preferable that the fluorine-containing polymer (E1) further contains one or more of the above-mentioned repeating units (1). By including this repeating unit (1), the receding contact angle is high during exposure, and the solubility in alkali is improved during development. That is, at the time of exposure, the structure of the general formula (1) is maintained, the receding contact angle is high without almost losing the effect of the monomer containing fluorine in the molecular structure, and then the solubility in alkali is obtained by the action of acid. It is increasing. The preferred monomers used for constituting the repeating unit (1) are the same as those already described.

  The proportion of the repeating unit (1) contained in the fluorine-containing polymer (E1) is usually 95 mol% or less, preferably 10 to 90 mol%, more preferably 10 to 85 mol%, based on all repeating units. is there. If the content ratio of the repeating unit (1) exceeds 95 mol%, it becomes difficult to set the receding contact angle to 70 ° or more, and elution of the radiation sensitive acid generator (B) and the like from the photoresist film. Tends to be difficult to suppress.

Further, the fluorine-containing polymer (E1), as a repeating unit other than the repeating units (1) and (6), the repeating units of the above (3) and (5) and other repeating units is also further contain Good. The total of the proportions of these repeating units contained in the fluorine-containing polymer (E1) is usually 70 mol% or less, preferably 65 mol% or less, more preferably 60 mol% or less, based on all repeating units. is there. If the total content of these repeating units exceeds 70 mol%, it becomes difficult to set the receding contact angle to 70 ° or more, and elution of the radiation sensitive acid generator (B) and the like from the photoresist film. Tends to be difficult to suppress.

  In the fluorine-containing polymer (E1), for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit is used to initiate radical polymerization of hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, etc. It can manufacture by superposing | polymerizing in a suitable solvent in presence of a chain transfer agent using an agent as needed.

  Examples of the solvent used for polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, norbornane. Cycloalkanes such as benzene, toluene, xylene, ethylbenzene, cumene and other aromatic hydrocarbons; chlorobutanes, bromohexanes, dichloroethanes, halogenated hydrocarbons such as hexamethylene dibromide, chlorobenzene; ethyl acetate, Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, di Ethers such as ethoxyethanes; Meta Lumpur, ethanol, 1-propanol, 2-propanol, may be mentioned alcohols such as 4-methyl-2-pentanol. These solvents can be used alone or in combination of two or more. The reaction temperature in 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.

  As a suitable example of a fluorine-containing polymer (E1), in addition to the polymer containing the repeating unit (6) represented by the general formula (9), the repeating represented by the following formulas (10) to (29) The thing which has a unit can be mentioned.

The amount of the fluorine-containing polymer (E1) is a fluorine含含containing compound (E), relative to the resin (A) 100 parts by mass of, 0. 1 to 40 parts by mass, preferably 0.5 to 35 parts by mass. When the amount of the fluorine-containing polymer (E1) used is less than 0.1 parts by mass, the effect (high receding angle and low elution) of the fluorine-containing polymer (E1) does not appear, and the receding contact angle of the photoresist film is It tends to decrease or it becomes difficult to suppress elution of the acid generator and the like from the photoresist film. On the other hand, if the amount of the fluorine-containing polymer (E1) used is more than 40 parts by mass, the depth of focus of isolated lines may be reduced or development defects may occur.

  The polystyrene-reduced weight average molecular weight (Mw) by GPC method of the fluorine-containing polymer (E1) is preferably 1,000 to 50,000, more preferably 1,000 to 40,000, and particularly preferably 1,000 to 30. , 000. When the Mw of the fluorine-containing polymer (E1) is less than 1,000, it tends to be difficult to obtain a sufficient receding contact angle. On the other hand, when the Mw of the fluorine-containing polymer (E1) is more than 50,000, the developability of the radiation-sensitive resin composition obtained using the same tends to be lowered. In addition, ratio (Mw / Mn) of Mw of a fluorine-containing polymer (E1) and the polystyrene number average molecular weight (Mn) by GPC method is 1-5 normally, Preferably it is 1-4.

  The smaller the amount of impurities such as halogen and metal contained in the fluorine-containing polymer (E), the better. By reducing the content of these impurities, the sensitivity, resolution, process stability, pattern shape, and the like of the radiation-sensitive resin composition obtained using the impurities can be further improved. Examples of the purification method of the fluorine-containing polymer (E) include chemical purification methods such as water washing and liquid-liquid extraction, and these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. And the like.

(Other ingredients)
Various additives, such as an alicyclic additive, surfactant, and a sensitizer, can be mix | blended with the radiation sensitive resin composition of this embodiment as needed.

An alicyclic additive 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, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α. -Butyrolactone ester, 1,3-adamantane dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane; t-butyl deoxycholic acid, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, 2-deoxycholic acid 2- Cyclohexyloxyethyl, deoxy Deoxycholic acid esters such as 3-oxocyclohexyl cholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester of deoxycholic acid; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, Lithocholic acid esters such as lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, din adipate - butyl, alkyl carboxylic acid esters such as adipate t- butyl or 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^{2, 5} 1 ^7,10 ] dodecane and the like. These alicyclic additives can be used singly or in combination of two or more.

  A surfactant is a component that exhibits an effect of improving coating properties, striation, 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, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173 (manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (made by Asahi Glass Co., Ltd.), etc. Can do. These surfactants can be used singly or in combination of two or more.

  The sensitizer absorbs radiation energy and transmits the absorbed energy to the radiation-sensitive acid generator (B). This has the effect of increasing the amount of acid produced, and has the effect of improving the apparent sensitivity of the radiation-sensitive resin composition. 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 individually by 1 type or in combination of 2 or more types. By adding a dye or pigment, the latent image in the exposed area can be visualized and the influence of halation during exposure can be reduced. Moreover, the adhesiveness with a board | substrate can be improved by mix | blending an adhesion aid.

  Further, components other than the above-mentioned components that can be added as additives include alkali-soluble resins, low-molecular alkali-solubility control agents having acid-dissociable protecting groups, antihalation agents, storage stabilizers, antifoaming agents. Etc.

2. Resist pattern formation method:
Next, the resist pattern forming method of the present invention will be described. In one embodiment of the resist pattern forming method of the present invention, a photoresist film made of the above-mentioned radiation-sensitive resin composition is formed on the surface of a substrate, and the refractive index at a wavelength of 193 nm is higher than that of air on the film surface. This is a method including an immersion exposure step of exposing a photoresist film by irradiating radiation with a high immersion exposure liquid directly in contact. The details will be described below.

  The radiation-sensitive resin composition that is one embodiment of the present invention described above is particularly useful as a chemically amplified resist. In such a chemically amplified resist, an acid-dissociable group in the resin (A) is dissociated by the action of an acid generated from a radiation-sensitive acid generator by exposure to generate a carboxyl group or the like. As a result, the solubility of the exposed portion in the photoresist film with respect to the alkaline developer is increased, so that the exposed portion is dissolved and removed by the alkaline developer to form a positive resist pattern.

  In order to form a resist pattern using the radiation-sensitive resin composition of this embodiment, first, a photoresist film is formed by applying a solution of the radiation-sensitive resin composition on a substrate by an appropriate application means. To do. Examples of the application means include spin coating, cast coating, roll coating, and the like. As the substrate, a silicon wafer, a wafer covered with aluminum, or the like can be used.

  Next, an immersion exposure liquid whose refractive index at a wavelength of 193 nm is higher than that of air is directly brought into contact with the film surface of the formed photoresist film. Specific examples of the liquid for immersion exposure include water. Here, “directly contact the liquid for immersion exposure on the film surface of the photoresist film” means an upper layer or the like usually disposed on the film surface of the photoresist film in general immersion exposure. The liquid for immersion exposure is directly brought into contact with the film surface of the photoresist film without interposing any protective film. By doing so, there is an advantage that the process of applying and peeling the upper protective film becomes unnecessary and the whole process is simplified.

  In order to maximize the potential of the radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12458, an organic or inorganic antireflection on the substrate to be used. It is also preferable to form a film. In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film may be provided on the photoresist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598. Good. Furthermore, in order to more effectively prevent elution of the radiation sensitive acid generator and the like from the photoresist film in immersion exposure, for example, a photoresist film as disclosed in JP-A-2005-352384, etc. An immersion protective film may be disposed on the top. These techniques can be used in combination.

  In some cases, after a heat treatment (hereinafter also referred to as “PB”) is performed in advance, the photoresist film is exposed to form a predetermined resist pattern. As radiation that can be used for exposure, visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, and the like can be appropriately selected according to the type of the radiation-sensitive acid generator (B) to be blended. it can. Especially, the far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) or KrF excimer laser (wavelength 248 nm) are preferable, and especially ArF excimer laser (wavelength 193 nm) is preferable.

  What is necessary is just to set suitably exposure conditions, such as exposure amount, according to the compounding composition of a radiation sensitive resin composition, the kind of additive, etc. Note that heat treatment (PEB) is preferably performed after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the resin (A) easily proceeds smoothly. The heating conditions for PEB vary depending on the composition of the radiation sensitive resin composition, but are usually 30 to 200 ° C, preferably 50 to 170 ° C.

  Next, the exposed photoresist film is developed to form a predetermined resist pattern. Examples of the developer used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. When the concentration of the alkaline aqueous solution is more than 10% by mass, the non-exposed part tends to be easily dissolved in the developer.

  When the developer is an alkaline aqueous solution, an organic solvent can be added to the alkaline aqueous solution. Examples of organic solvents that can be added include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, n Alcohols such as -propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; tetrahydrofuran, dioxane, etc. Ethers; esters such as ethyl acetate, n-butyl acetate, i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonyl acetone, dimethylformamide, and the like. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

  The addition amount of the organic solvent is preferably 100% by volume or less with respect to the alkaline aqueous solution. If the addition amount of the organic solvent is more than 100% by volume, the developability tends to decrease and the amount of development remaining in the exposed area tends to increase. Further, when the developer is an alkaline aqueous solution, an appropriate amount of a surfactant or the like can be added to the alkaline aqueous solution. In addition, after developing with a developing solution, it may generally be washed with water and dried.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Mw and Mn]: Tosoh GPC columns (model number “G2000HXL”: 2, model number “G3000HXL”: 1, model number “G4000HXL”: 1), flow rate: 1.0 ml / min, elution solvent : Tetrahydrofuran, column temperature: Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C. The degree of dispersion (Mw / Mn) was calculated from the GPC measurement results.

^[13 C-NMR analysis]: ¹³ C-NMR of the polymer, were measured and analyzed using a JEOL Co., Ltd. under the trade name "JNM-EX270".

  [Amount of low molecular weight component derived from monomer]: Using a trade name “Intersil ODS-25 μm column” (4.6 mmφ × 250 mm) manufactured by GL Sciences, flow rate: 1.0 ml / min, elution solvent: acrylonitrile / Measured by high performance liquid chromatography (HPLC) under the analysis conditions of 0.1% phosphoric acid aqueous solution.

(Synthesis of resin (A) and fluorine-containing polymer (E1))
Hereinafter, synthesis of the resin (A) and the fluorine-containing polymer (E1) will be described. The monomers (M-1) to (M-5) used in the synthesis are shown below.

(1) Synthesis of resin (A-1):
Monomer (M-1) 53.93 g (50 mol%), monomer (M-2) 35.38 g (40 mol%), and monomer (M-3) 10.69 g (10 mol%) ) Was dissolved in 200 g of 2-butanone, and 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to prepare a monomer solution. In addition, 100 g of 2-butanone was charged into a 500 ml three-necked flask and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring, and the monomer solution was added dropwise over 3 hours using a dropping funnel. 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. The cooled polymerization solution was put into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice on the slurry with 400 g of methanol, filtered and dried at 50 ° C. for 17 hours to obtain a white powder copolymer (74 g, yield 74). %). Mw of the obtained copolymer was 6900, and Mw / Mn was 1.70. As a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the monomers (M-1), (M-2), and (M-3) was 53.0: 37.2: 9. .8 (mol%) copolymer. This copolymer was referred to as “resin (A-1)”. In addition, content of the low molecular weight component derived from each monomer in resin (A-1) was 0.03% with respect to 100% of this polymer.

(2) Synthesis of fluorine-containing polymer (E1-1):
Monomer (M-2) 32.15 g (70 mol%) and monomer (M-4) 17.85 g (30 mol%) were dissolved in 2-butanone 50 g, and dimethyl 2,2 ′. -A monomer solution was prepared by adding 4.64 g of azobis (2-methylpropionate). In addition, 100 g of 2-butanone was charged into a 500 ml three-necked flask and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring, and the monomer solution was added dropwise over 3 hours using a dropping funnel. 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. The cooled polymerization solution was put into 1000 g of a mixed solvent of methanol / water = 4/1, and the precipitated white powder was filtered off. The filtered white powder was washed twice on the slurry with 200 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder copolymer (41 g, yield 82). %). Mw of the obtained copolymer was 5900, and Mw / Mn was 1.87. Moreover, as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the monomers (M-2) and (M-4) was a copolymer having a content of 71.6: 28.4 (mol%). there were. This copolymer was designated as a fluorine-containing polymer (E1-1).

(3) Synthesis of fluorine-containing polymer (E1-2):
Monomer (M-2) 40.70 g (85 mol%) and monomer (M-4) 9.30 g (15 mol%) were dissolved in 2-butanone 50 g, and further dimethyl 2,2 ′. -Perform the same operation as the above-mentioned "Synthesis of fluorine-containing polymer (E-1)" except that 7.26 g of azobis (2-methylpropionate) was added to prepare a monomer solution. Thus, a white powder copolymer was obtained (40 g, yield 80%). Mw of the obtained copolymer was 4000, and Mw / Mn was 1.40. In addition, as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the monomers (M-2) and (M-4) was a copolymer of 86.3: 13.7 (mol%). there were. This copolymer was designated as a fluorine-containing polymer (E1-2).

(4) Synthesis of fluorine-containing polymer (E1-3):
Monomer (M-1) 8.49 g (15 mol%), (M-2) 32.49 g (70 mol%), and monomer (M-4) 9.02 g (15 mol%) Except that the monomer solution was prepared by dissolving in 50 g of 2-butanone and further adding 2.93 g of dimethyl 2,2′-azobis (2-methylpropionate), the above-mentioned “fluorine-containing polymer ( By performing an operation equivalent to “synthesis of E-1)”, a white powder copolymer was obtained (36 g, yield 78%). Mw of the obtained copolymer is 8000, Mw / Mn is 1.60, and as a result of ¹³ C-NMR analysis, it is derived from monomers (M-1), (M-2), and (M-4). It was a copolymer having a content of each repeating unit of 15.8: 70.1: 14.1 (mol%). This copolymer was designated as a fluorine-containing polymer (E1-3).

(5) Synthesis of fluorine-containing polymer (E1-4):
Monomer (M-2) 30.80 g (70 mol%), (M-4) 8.55 g (15 mol%), monomer (M-5) 10.65 g (15 mol%) -The above-mentioned "fluorine-containing polymer (E) except that it was dissolved in 50 g of butanone and 2.78 g of dimethyl 2,2'-azobis (2-methylpropionate) was further added to prepare a monomer solution. The same operation as in “Synthesis of -1)” was performed to obtain a white powder copolymer (34 g, yield 68%). Mw of the obtained copolymer was 9000 and Mw / Mn was 1.80. Moreover, as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the monomers (M-2), (M-4) and (M-5) was 70.6: 13.8: 15. It was 6 (mol%) copolymer. This copolymer was designated as a fluorine-containing polymer (E1-4).

( Reference Example 1 )
99 parts of resin (A-1), 1.5 parts of acid generator (B-1), 6.0 parts of acid generator (B-2), 0.65 part of nitrogen-containing compound (C-1), solvent ( D-1) A radiation-sensitive resin composition ( Reference Example 1 ) was prepared by mixing 1400 parts, solvent (D-2) 30 parts, and fluorine-containing polymer (E1-1) 1 part.

(Examples 1 to 10 , Comparative Example 1 , Reference Examples 2 to 6 )
A radiation-sensitive resin composition (Examples 1 to 10 , Comparative Example 1 and Reference Examples 2 to 6 ) was prepared in the same manner as in Reference Example 1 , except that the formulation shown in Table 1 was used. In addition, the detail of each used component (Table 1) is shown below.

(Acid generator (B))
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (B-2): 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro-n-butanesulfonate

(Nitrogen-containing compound (C))
(C-1): Nt-butoxycarbonyl-4-hydroxypiperidine

(Solvent (D))
(D-1): Propylene glycol monomethyl ether acetate (D-2): Gamma-butyrolactone

(Evaluation of radiation-sensitive resin composition)
Examples 1-10, Comparative Example 1, the radiation-sensitive resin composition of Reference Example 1-6, was subjected to various evaluations described below. The evaluation results are shown in Table 2. Also. The evaluation method is as follows.

[Measurement of (F ₁ ) / (C ₁ ) ratio]: For the formed photoresist film, a photoelectron spectroscope (trade name “Quantum 2000”, manufactured by ULVAC-PHI) is used, and the two generated by X-ray surface irradiation. Surface elemental analysis (ESCA) was performed to measure secondary electrons. The measurement angle was 90 °, the element distribution in the depth direction of the photoresist film was measured, and the ratio of fluorine content (F ₁ (atom%)) to carbon content (C ₁ (atom%)) A value of (F ₁ ) / (C ₁ ) was calculated. Here, by analyzing at a measurement angle of 90 °, it is possible to measure the element distribution from the film surface to a depth of about 5 nm.

  [Measurement of Elution Amount]: As shown in FIG. 1, HMDS (hexamethyldisilazane) 31 treatment (100 ° C., 60 seconds) was performed in advance using a trade name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron). In addition, a silicon rubber sheet 4 (manufactured by Kureha Elastomer Co., Ltd., thickness: 1.0 mm, shape: square with a side of 30 cm) at the center on an 8-inch silicon wafer 3 is cut into a circular shape with a center of 11.3 cm in diameter. ) Was placed. Next, 10 ml of ultrapure water 5 was filled in the hollowed portion at the center of the silicon rubber sheet 4 using a 10 ml hole pipette. Thereafter, a lower layer antireflection film (trade name “ARC29A”, manufactured by Brewer Science Co., Ltd.) 61 having a film thickness of 77 nm was formed using a trade name “CLEAN TRACK ACT8”. Next, a radiation sensitive resin composition is spin-coated on the lower antireflection film 61 using a trade name “CLEAN TRACK ACT8”, and baked (115 ° C., 60 seconds) to form a photoresist film having a thickness of 205 nm. The silicon wafer 6 on which the 62 was formed was placed on the silicon rubber sheet 4 so that the film surface of the photoresist film 62 was in contact with the ultrapure water 5 and the ultrapure water 5 was not leaked. After maintaining for 10 seconds in that state, the silicon wafer 6 was removed, and ultrapure water 5 was collected as a sample for analysis with a glass syringe. Note that the recovery rate of ultrapure water after holding was 95% or more.

Using LC-MS (liquid chromatograph mass spectrometer, LC part: trade name “SERIES1100” (manufactured by AGILENT), MS part: trade name “Mariner” (manufactured by Perseptive Biosystems, Inc.)), the following measurement was performed. According to the conditions, the peak intensity of the anion portion of the radiation-sensitive acid generator in the collected ultrapure water 5 was measured. At that time, each of the peak intensities of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the photoacid generator was measured under the following measurement conditions to prepare a calibration curve, and the elution amount was calculated from the peak intensity using this calibration curve. Similarly, each of the peak intensities of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the acid diffusion control agent is measured under the following measurement conditions to create a calibration curve, and the acid diffusion control agent is calculated from the peak intensity using this calibration curve. The amount of elution was calculated. In addition, when the elution amount was more than 1.0 × 10 ⁻¹¹ mol / cm ² , “x”, 1.0 × 10 ⁻¹¹ mol / cm ^{2 to} 5.0 × 10 ⁻¹² mol / cm ² When it was less than “Δ” and less than 5.0 × 10 ⁻¹² mol / cm ² , it was evaluated as “◯”.
(Measurement condition)
Column used: Trade name “CAPCELL PAK MG” (manufactured by Shiseido Co., Ltd.), 1 flow rate: 0.2 ml / min
Elution solvent: Water / methanol (3/7) with 0.1% formic acid added Measurement temperature: 35 ° C

  [Measurement of receding contact angle]: Using a contact angle meter (trade name “DSA-10”) manufactured by KRUS, a substrate (wafer) on which a coating film with a radiation-sensitive resin composition was formed was prepared. The measurement was promptly performed according to the following procedure in an environment of room temperature: 23 ° C., humidity: 45%, and normal pressure.

(1) Adjust the wafer stage position.
(2) Set the wafer on the stage.
(3) Inject water into the needle.
(4) Finely adjust the position of the needle.
(5) Drain water from the needle to form 25 μl water droplets on the wafer.
(6) Pull out the needle from the water drop.
(7) Pull the needle down again to the position adjusted in (4) above.
(8) Aspirate a water droplet from the needle at a speed of 10 μl / min for 90 seconds. At the same time, the contact angle is measured every second (total 90 times).
(9) An average value is calculated for a total of 20 contact angles from the time when the contact angle is stabilized, and this average value is defined as a “retreat contact angle”.

  [Sensitivity]: A 12-inch silicon wafer having a 77 nm-thick lower-layer antireflection film (trade name “ARC29A” (Brewer Science)) formed on the surface thereof was used as a substrate. In addition, the brand name “CLEAN TRACK ACT8” (manufactured by Tokyo Electron) was used for forming the lower antireflection film. On this substrate, a radiation sensitive resin composition is spin-coated using the trade name “CLEAN TRACK ACT8”, and baking (PB) is performed at 120 ° C. for 60 seconds to form a 205 nm-thick photoresist film. did. The formed photoresist film was exposed through a mask pattern using an ArF excimer laser exposure apparatus (trade name “NSR S306C” (manufactured by Nikon), certification condition: NA 0.78 sigma 0.93 / 0.69). After performing PEB at 115 ° C. for 60 seconds, development was performed at 23 ° C. for 30 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution. After washing with water and drying, a positive resist pattern was formed. At this time, an exposure amount for forming a line-and-space pattern (1L1S) having a line width of 90 nm in a one-to-one line width was defined as an optimum exposure amount, and this optimum exposure amount was defined as sensitivity. A scanning electron microscope (trade name “S-9380” (manufactured by Hitachi High-Technologies Corporation) was used for this measurement.

  [Cross-sectional shape of the pattern]: The cross-sectional shape of the 90 nm line and space pattern was observed using an electron microscope (trade name “S-4800” (manufactured by Hitachi High-Technologies Corporation)), as shown in FIG. The line width in the middle of the resist pattern 2 (intermediate line width Lb) and the line width in the upper part of the film (upper line width La) were measured. The case where it was within the range of 0.9 ≦ (La−Lb) /Lb≦1.1 was evaluated as “good”, and the case where it was out of the range was evaluated as “bad”.

As shown in Table 2, when the radiation sensitive resin compositions of Examples 1 to 10 were used, contact was made during immersion exposure as compared to the case of using the radiation sensitive resin composition of Comparative Example 1. It is clear that the amount of eluate in the water is small, gives a high receding contact angle, and the pattern shape is also good.

  The radiation-sensitive resin composition of the present invention can be particularly suitably used in lithography that will be miniaturized in the future.

It is a schematic diagram explaining the method of producing the sample for a measurement of the elution amount. It is sectional drawing which shows a line and space pattern typically.

Explanation of symbols

1: substrate, 2: resist pattern, 3: silicon wafer, 31: HMDS, 4: silicon rubber sheet, 5: ultrapure water, 6: silicon wafer, 61: lower antireflection film, 62: photoresist film, La: Upper line width, Lb: Intermediate line width

Claims (4)

Resin (A) that becomes alkali-soluble by the action of acid (excluding those having fluorine atoms), radiation-sensitive acid generator (B), nitrogen-containing compound (C), solvent (D), and fluorine-containing compound Containing (E),
The compounding quantity of the said fluorine-containing compound (E) is 0.1-40 mass parts with respect to 100 mass parts of said resin (A),
The fluorine-containing compound (E) is a fluorine-containing polymer (E1) containing a repeating unit represented by the following general formula (9) (however, represented by the following formulas (E-1) to (E-27)). Excluding repeating units),
In a resist pattern forming method including an immersion exposure step of exposing a photoresist film formed on a substrate by irradiating radiation in a state where an immersion exposure liquid having a refractive index higher than that of air is interposed at a wavelength of 193 nm A radiation-sensitive resin composition used for forming the photoresist film,
When the photoresist film is formed, the fluorine content (F ₁ (atom%)) and carbon content (C ₁ (atom%)) of the photoresist film, which are measured and calculated by the following surface elemental analysis, The ratio of (F ₁ ) / (C ₁ ) = 0.01 to 0.6, and the fluorine content (F ₂ (atom%)) and carbon content ( C ₂ (atom%)) is a radiation-sensitive resin composition (provided by the following formula (A-1)) where (F ₂ ) / (C ₂ ) = 0.004 to 0.05 A resin comprising a repeating unit represented by the following general formula (A-2), a repeating unit represented by the following formula (A-1) and a repeating unit represented by the following formula (A-3): Resin, repeating unit represented by the following formula (A-1) and the following formula Resin comprising a repeating unit represented by (A-4), a resin comprising a repeating unit represented by the following formula (A-5) and a repeating unit represented by the following formula (A-6), A resin comprising a repeating unit represented by formula (-5) and a repeating unit represented by formula (A-7), a repeating unit represented by formula (A-5) and formula (A-8) A resin composed of a repeating unit, a resin composed of a repeating unit represented by the following formula (A-5) and a repeating unit represented by the following formula (A-9), represented by the following formula (A-5) Resin comprising a repeating unit represented by the following formula (A-10) or a repeating unit represented by the following formula (A-5) and a repeating unit represented by the following formula (A-11) Excluding those containing resin.) (Surface elemental analysis): A photoelectron spectrometer is used to irradiate the film surface of the photoresist film with an X-ray, and the amount of secondary electrons generated is measured at an angle of 90 ° with respect to the film surface. The distribution amounts of fluorine atoms and carbon atoms in the photoresist film are measured.

(In the general formula (9), R ¹⁶ represents hydrogen, methyl group, or trifluoromethyl group, and Z represents a single bond, oxygen atom, sulfur atom, carbonyloxy group, oxycarbonyl group, amide group, sulfonylamide group. or .R ¹⁷ showing the urethane groups contain at least one or more fluorine atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, or a monovalent alicyclic having 4 to 20 carbon atoms Represents a hydrocarbon group or a derivative thereof.)

(In the general formula (A-2), R represents a hydrogen atom or a methoxymethyl group. However, 40% of all R in the general formula (A-2) is a methoxymethyl group.)

The resin (A) is
A repeating unit (1) having a structure in which alkali solubility is expressed by the action of an acid;
A repeating unit (2) having a lactone structure;
The radiation-sensitive resin composition according to claim 1, wherein the radiation-sensitive resin composition contains at least one of each of the above and is insoluble in alkali or hardly soluble. A photoresist film made of the radiation-sensitive resin composition according to claim 1 or 2 is formed on the surface of the substrate,
An immersion exposure step of exposing the photoresist film by irradiating the photoresist film with a radiation exposure liquid having a refractive index higher than that of air at a wavelength of 193 nm directly in contact with the film surface; Resist pattern forming method.   4. The radiation according to claim 3, wherein the liquid immersion exposure liquid is irradiated with radiation on the film surface of the photoresist film in a state where the liquid for immersion exposure is directly contacted without forming a protective film. 5. Resist pattern forming method.

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