JP5935651B2 - Resist composition for extreme ultraviolet light and electron beam exposure, and resist pattern forming method using the same - Google Patents

Description

  The present invention relates to a resist composition for extreme ultraviolet (EUV) light and electron (EB) beam exposure, and a resist pattern forming method using the resist composition for EUV light and EB exposure. Specifically, a resist composition using EUV light or EB as an exposure source using a polymer in which fullerene derivatives having a specific structure are linked via an acid-dissociable partial structure, and resist pattern formation using this resist composition It is about the method.

  In recent years, with the high integration and high speed of LSI, pattern miniaturization is rapidly progressing. As a pattern miniaturization technique, generally, the wavelength of an exposure source is shortened. Specifically, we have shifted from ultraviolet rays such as g-line and i-line to lithography technology using KrF excimer laser (248 nm) and ArF excimer laser (193 nm) as an exposure source, and recently for further miniaturization. Further, mass production is also being studied for immersion ArF lithography using the refractive index of water and double patterning technology for performing exposure twice. Further, as a technique using a short wavelength high energy beam, a lithography technique using EB (electron beam) or EUV (extreme ultraviolet light: wavelength 13.5 nm) light as an exposure source has been studied. While EB exposure has a problem of low throughput, it is possible to form a very fine pattern directly without passing through a mask, whereas the wavelength when EUV light is used is compared with the wavelength of ArF. Therefore, it has attracted attention as a technique for forming ultrafine patterns with high productivity.

  The resist material is required to have lithography characteristics such as sensitivity to exposure sources having these various wavelengths and resolution capable of forming a fine pattern. As a resist composition that satisfies these requirements, it has high solubility in polar organic solvents such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME), and can form a uniform film. A base material component is used in which a photochemical reaction occurs in accordance with an energy distribution formed by various exposures such as a line and an electron beam, and the solubility in a developer changes. Among these photochemical reactions, in particular, a base material component whose solubility in an alkaline developer is changed by the action of an acid, an acid generator that generates an acid upon exposure, and line edge roughness, which is the roughness of the side surface of a line width or resist pattern. (Line Edge Roughness, hereinafter abbreviated as LER) and line width roughness (Line Width Roughness, hereinafter abbreviated as LWR), which is the roughness of the line width caused by the LER of the left and right edges of the line. A chemically amplified resist composition containing a nitrogen-containing organic compound is used for forming a fine pattern. Among these, a positive resist composition is a resist composition used for a resist in which an exposed portion is dissolved in an alkaline developer, and a negative resist is a resist composition used in a resist in which an exposed portion is not dissolved in an alkaline developer. It is called a composition.

  Conventionally, polymers such as novolak resins, polyhydroxystyrenes, methacrylic resins and copolymers thereof have been used as the base component of such chemically amplified resist compositions. In addition, these polymers are applied to positive resist compositions by substituting part of hydroxyl groups and carboxyl groups of these polymers with acid dissociable organic groups.

When an ultrafine pattern is formed using such a pattern forming material, so-called pattern collapse such as bending, folding and peeling of the pattern occurs. This phenomenon depends on the ratio between the pattern height and the line width, that is, the aspect ratio. In the case of an extremely fine pattern, it is said that an aspect ratio of about 2 to 3 is appropriate.
That is, when trying to form a pattern with a line width of 20 nm, it is necessary to form the pattern with a very thin film thickness of around 50 nm. This thinning of the resist film means that the etching resistance of the resist material becomes more important. As a matter of course, since the resist film is made thinner in pattern formation with a line width of 20 nm or less, it can be said that the improvement in etching resistance of the resist material is essential in the formation of a fine pattern.

  Further, in lithography using EUV light as an exposure source, EUV light is absorbed in the atmosphere, so that exposure is performed under high vacuum. Volatile components (outgas) generated from the resist composition during exposure hinders vacuum conditions and, when attached to an optical mirror or reflection mask, forms a hydrocarbon-based deposit film relatively easily by EUV light irradiation. It is known to cause deterioration of resist sensitivity and resolution. Therefore, development of a resist composition for EUV light exposure with a small outgas generation amount is desired.

  However, although the polymer used as a base material component that has been used conventionally has high pattern forming ability, the etching resistance is not always sufficient, and the amount of outgas generated is large, so that an ultrafine pattern using EUV light or EB exposure is used. Was insufficient for the formation of.

By the way, since a large amount method for the synthesis of C ₆₀ fullerene has been established in 1990, studies on fullerene has been energetically carried out. Fullerenes and fullerene derivatives have a low molecular weight and can be produced with a single compound depending on the production method, which is advantageous for forming a fine pattern. Further, it is generally said that there is a correlation between the carbon concentration of the resist film and the dry etching resistance, and fullerenes and fullerene derivatives having a very high carbon concentration have a feature of being excellent in etching resistance.

  For this reason, a fullerene derivative having solubility in a solvent used for resist applications has been developed (Patent Document 1), and KrF exposure and EB exposure are actually performed, and their usefulness has been confirmed. (Patent Document 2).

JP 2006-56878 A JP 2008-33102 A

Org.Lett.2000,2,1919 J.Organomet.Chem.2002,652,31 J. Mater. Chem. 2002, 12, 2109 Org.Lett. 2003,5,4461 J. Am. Chem. Soc. 2004, 126, 432

  An object of the present invention is to provide a resist composition that provides a resist film with high etching resistance and reduced outgas in EUV and EB lithography capable of forming an ultrafine pattern, and a resist pattern forming method using the same. To do.

  As a result of intensive studies to solve the above problems, the present inventors have used a chemically amplified resist composition containing a polymer in which a fullerene derivative having a specific structure is linked via an acid-dissociable partial structure. The inventors have found that the etching resistance is extremely high and the outgas can be reduced, and the present invention has been completed.

  That is, the gist of the present invention resides in the following [1] to [11].

[1] A substrate component (A) whose alkali solubility is changed by the action of an acid, an acid generator (B) that generates an acid upon exposure, a nitrogen-containing organic compound (C), and an organic solvent (D). A resist composition for exposure to extreme ultraviolet light and electron beams.
However, the base material component (A) has an acid dissociable partial structure (X) represented by either the following (X ¹ ) or (X ² ) with respect to the repeating unit constituting the polymer main chain. A polymer having a structural unit to which a fullerene skeleton is linked (hereinafter referred to as “structural unit (I)”).

(Wherein, ^{R 2} represents an organic group or a hydrogen atom having 1 to 20 carbon ^atoms, R ^1, R 3 ^{~R 6} each independently represent an organic group having 1 to 20 carbon atoms, ^{R 7} represents a single bond or Represents an organic group having 1 to 20 carbon atoms, which may have an arbitrary substituent, and R ² and R ³ , R ⁵ and R ⁶ are bonded to each other to form a ring; In (X ¹ ), R ¹ is bonded to the fullerene skeleton, R ³ is bonded to a repeating unit constituting the polymer main chain, and in (X ² ), R ⁴ is bonded to the fullerene skeleton, R ⁷ is bonded to a repeating unit constituting the polymer main chain.)

[2] As a base material component (A), a positive composition containing an alkali-insoluble or alkali-insoluble polymer protected with an acid-dissociable organic group, which becomes alkali-soluble when the acid-dissociable organic group is dissociated. The resist composition for extreme ultraviolet light and electron beam exposure according to [1], which is a mold resist composition.

[3] The base component (A) is a hydroxyphenyl group, a hydroxynaphthyl group, and a carboxyl group (provided that each of these groups further represents the structural unit (I) and the repeating unit constituting the polymer main chain. A structural unit having at least one substituent (Y) selected from the group consisting of (which may have a substituent) and the substituent (Y) being protected with an acid-dissociable organic group The resist composition for extreme ultraviolet light and electron beam exposure according to [2], wherein the resist composition is referred to as “structural unit (II)”.

[4] The resist composition for extreme ultraviolet light and electron beam exposure according to [1], which is a negative resist composition further containing a crosslinking agent component (E).

[5] The resist composition for extreme ultraviolet light and electron beam exposure according to any one of [1] to [4], wherein the fullerene skeleton has a partial structure represented by the following formula (1): .

(In the formula ^{(1), C} 1 ~C ¹⁰ represents a carbon atom constituting the fullerene skeleton, ^{C 1} is bonded to ^{R 1} or ^{R 4} in the acid-dissociable moiety (X), ^{C 6} To C ¹⁰ are each independently bonded to a group represented by the following formula (2) (hereinafter sometimes abbreviated as “R ²⁰ ”).

(In the formula (2), Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, and R has a hydrogen atom, an alkyl group which may have a substituent, or a substituent. And represents an aryl group or an acid dissociable organic group, and n represents an integer of 1 to 3.)

[6] R ³ and / or R ^{7 in the} acid dissociable partial structure (X) may have a substituent, a phenylene group, a naphthylene group, a carbonyl group, a phenylenecarbonyl group, a naphthylenecarbonyl group, Any one of [1] to [5], which is at least one selected from the group consisting of a phenyleneoxyalkylene group, a phenyleneoxyphenylene group, a naphthyleneoxyalkylene group, and a naphthyleneoxyphenylene group. A resist composition for exposure to extreme ultraviolet light and electron beams.

[7] The ratio of the structural unit (I) in all repeating units constituting the polymer main chain of the base component (A) is from 0.1 mol% to 30 mol% [1] to [6] ] The resist composition for extreme ultraviolet light and electron beam exposure as described in any of the above.

[8] The resist composition for extreme ultraviolet light and electron beam exposure according to any one of [1] to [7], wherein the acid generator (B) is an onium salt acid generator.

[9] The onium salt acid generator is a sulfonium salt acid generator represented by the following formula (3) and / or an iodonium salt acid generator represented by the following formula (4): 8] The resist composition for exposure to extreme ultraviolet light and electron beam.

(In formulas (3) and (4), R ^{8 to} R ¹⁰ each independently represents an organic group having 1 to 20 carbon atoms, and R ¹¹ is a linear, branched or cyclic alkyl group or fluorinated. Represents an alkyl group, R ⁸ and R ⁹ may be bonded to each other to form a ring.)

[10] The resist composition for extreme ultraviolet light and electron beam exposure according to any one of [1] to [9], wherein the nitrogen-containing organic compound (C) is a tertiary aliphatic amine.

[11] A step of applying a resist composition for extreme ultraviolet light and electron beam exposure according to any one of [1] to [10] on a substrate to form a resist film, a step of heat-treating the resist film, A resist pattern forming method, comprising: a step of selectively exposing the resist film to extreme ultraviolet light or an electron beam; and a step of developing the resist film after the exposure to form a resist pattern.

  According to the present invention, it is possible to provide a resist composition for EUV light and EB exposure that has extremely high etching resistance and generates a small amount of outgas, and the resist composition for EUV light and EB exposure that uses the resist composition of the present invention. According to the resist pattern forming method, a resist pattern having excellent etching resistance can be industrially advantageously formed.

  Hereinafter, although an embodiment of the present invention is described in detail, the present invention is not limited to the following contents, and can be arbitrarily changed and implemented without departing from the gist thereof.

[1. Resist composition]
The resist composition for exposure to EUV light and EB of the present invention (hereinafter sometimes referred to as “resist composition of the present invention”) is a base component (A) whose alkali solubility is changed by the action of an acid, exposure Contains an acid generator (B) that generates an acid, a nitrogen-containing organic compound (C), and an organic solvent (D).
In addition, the base component (A) has an acid dissociable partial structure (X) represented by either the following (X ¹ ) or (X ² ) with respect to the repeating unit constituting the polymer main chain. And the structural unit (I) to which the fullerene skeleton is linked.

(However, R ² represents an organic group having 1 to 20 carbon atoms or a hydrogen atom, R ¹ and R ^{3 to} R ⁶ each independently represents an organic group having 1 to 20 carbon atoms, and R ⁷ represents a single atom. Represents a bond or an organic group having 1 to 20 carbon atoms, which may have an arbitrary substituent, and R ² and R ³ , R ⁵ and R ⁶ are bonded to each other to form a ring; In (X ¹ ), R ¹ is bonded to the fullerene skeleton, R ³ is bonded to a repeating unit constituting the polymer main chain, and in (X ² ), R ⁴ is bonded to the fullerene skeleton. R ⁷ is bonded to a repeating unit constituting the polymer main chain.)

  The base component (A) whose alkali solubility is changed by the action of an acid, that is, the base component (A) whose solubility in an alkali developer is changed by the action of an acid is alkali developed by the action of an acid generated during exposure. The solubility in the liquid may be increased, or the solubility in the alkaline developer may be reduced. The resist composition of the present invention is a positive resist composition when the base component (A) whose alkali solubility is changed by the action of an acid is the former, and a negative resist composition in the latter. The resist composition of the present invention may be a positive resist composition or a negative resist composition.

  When the resist composition of the present invention is a positive resist composition, the fullerene linked to the acid dissociable partial structure (X) is usually connected to the base component (A) whose alkali solubility is changed by the action of an acid. Those having an acid dissociable organic group in addition to the skeleton are preferably used. In the positive resist composition, when acid is generated from the acid generator (B) by EUV light exposure or EB exposure at the time of resist pattern formation, the acid is separated from the acid dissociable partial structure (X) and the acid on the base component (A). By reacting with and reacting with dissociable organic groups, and dissociating them, the resist composition is insoluble or hardly soluble in an alkaline developer in an EUV light exposure part or EB exposure part, and from an alkali developer to an alkali developer. It becomes soluble and alkali development is possible.

  When the resist composition of the present invention is a negative resist composition, the resist composition of the present invention is a base component (A) whose alkali solubility is changed by the action of an acid, and an acid generator that generates an acid upon exposure. In addition to the agent (B), the nitrogen-containing organic compound (C) and the organic solvent (D), it is preferable to further contain a crosslinking agent component (E). The negative resist composition comprises a base material component (A) and a crosslinking agent whose alkali solubility is changed by the action of the acid when an acid is generated from the acid generator (B) by EUV light exposure or EB exposure during resist pattern formation. Crosslinking occurs between the component (E) and the solubility of the resist composition in the alkaline developer in the EUV light exposed part or EB exposed part changes from soluble to insoluble or hardly soluble, thereby enabling alkaline development. Therefore, the base component (A) before exposure is soluble in an alkaline developer having at least one functional group having an affinity with an alkaline developer, for example, an acidic functional group such as a phenolic hydroxyl group or a carboxyl group. This is an alkali-soluble resin.

  In the present invention, “alkali-soluble” means 50% of the initial film thickness of the film under the alkali development conditions employed when a resist pattern is formed from a resist film formed using the resist composition. The above means a property that does not remain after development, that is, 50% or less is dissolved and removed, and “alkali insoluble” or “alkali poorly soluble” means a property that remains 50% or more of the initial film thickness.

  In both positive and negative resist compositions, when the substrate component (A) contains a fullerene skeleton, the carbon concentration that correlates with the dry etching resistance increases, so that the etching resistance is enhanced. Moreover, since the acid dissociable partial structure (X) is included, the contrast difference in the solubility of the alkaline developer due to the acid can be increased. Furthermore, since the radical trap performance by the fullerene skeleton is also provided, the outgas generation amount is small.

[2. Base component (A) whose alkali solubility is changed by the action of an acid]
The base component (A) is a polymer having a structural unit (I) in which a fullerene skeleton is linked via an acid-dissociable partial structure (X) to a repeating unit constituting the polymer main chain.

  When the resist composition of the present invention is a positive resist composition, the substrate component (A) is composed of a structural unit (I) and a repeating unit constituting the polymer main chain, a hydroxyphenyl group, a hydroxynaphthyl group. And at least one substituent (Y) selected from the group consisting of a group and a carboxyl group (however, each of these groups may further have a substituent), and the substituent (Y) is an acid A copolymer having a structural unit protected by a dissociable organic group (hereinafter referred to as “structural unit (II)”) is preferable.

Thus, by having an acid dissociable organic group separately from the acid dissociable partial structure (X), the acid dissociable partial structure (by the acid generated from the acid generator (B) by EUV light exposure or EB exposure) X) and the acid dissociable organic group are dissociated, the ratio of the acid dissociable group in the polymer is increased, and the contrast difference of the alkali developer solubility can be increased, which is preferable.
That is, in general, it is difficult to synthesize a fullerene skeleton into a polymer main chain via an acid-dissociable partial structure (X) at a high introduction rate due to the bulkiness of the fullerene skeleton. For this reason, in the polymer having only the structural unit (I), the content of the acid-dissociable partial structure (X) is small, so that the contrast difference in alkali developer solubility tends to be low. On the other hand, by forming a copolymer having the structural unit (II) in addition to the structural unit (I), the content of acid dissociable groups in the entire polymer is increased to increase the contrast difference, that is, a resist material. Can function as.

[2-1. Polymer main chain]
The polymer main chain of the substrate component (A) is preferably a polyethylene chain. Accordingly, the base component (A) is preferably one in which the structural unit (I) is introduced to a polymer whose main chain is a polyethylene chain, such as polyhydroxystyrene, polyacrylic acid, polymethacrylic acid, and the like. It is preferable that an acid dissociable organic group or a substituent (Y) and an acid dissociable organic group are introduced.

[2-2. Structural unit (I)]
In the structural unit (I), the fullerene skeleton is linked to the repeating unit constituting the polymer main chain of the base component (A) via the acid dissociable partial structure (X).

[2-2-1. Acid dissociable partial structure (X)]
The acid dissociable partial structure (X) is represented by either (X ¹ ) or (X ² ) below.

Said R < ¹ > -R < ⁷ > represents a C1-C20 organic group. These organic groups may have an arbitrary substituent. R ² may be a hydrogen atom in addition to the organic group, and R ⁷ may be a single bond in addition to the organic group. R ² and R ³ may be bonded to each other to form a ring. R ⁵ and R ⁶ may be similarly bonded to each other to form a ring.

Among the organic groups of R ^{1 to} R ⁷ , R ¹ and R ⁴ are each a linking group bonded to a fullerene skeleton, R ³ and R ⁷ are linking groups bonded to a repeating unit constituting the polymer main chain, and R ¹ , R ³ , R ⁴ is a divalent organic group, and R ⁷ is a divalent organic group or a single bond. R ² is a monovalent organic group or a hydrogen atom, and R ⁵ and R ⁶ are monovalent organic groups.

Specific examples of the monovalent organic group of R ² , R ⁵ and R ⁶ include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxyphenyl group, an aralkyl group, a heterocyclic group, an alkoxy group, and an ester group. Can be mentioned.

Among the above organic groups, the alkyl group includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl. A linear or branched alkyl group such as a group; and a cyclic alkyl group such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alkenyl group include linear or branched alkenyl groups such as a vinyl group, propenyl group, and hexenyl group; and cyclic alkenyl groups such as a cyclopentenyl group and a cyclohexenyl group. Examples of the alkynyl group include alkynyl groups such as ethynyl group, methylethynyl group, and 2-propynyl group (propargyl group). Examples of the aryl group include a phenyl group, a naphthyl group, and a toluyl group. A methoxyphenyl group etc. are mentioned as an alkoxyphenyl group. Examples of the aralkyl group include a benzyl group and a phenylethyl group. Examples of the heterocyclic group include a thienyl group, a pyridyl group, and a furyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. Examples of the ester group include an ethyl ester group and a butyl ester group. Of these, an alkyl group having 1 to 20 carbon atoms is preferable from the viewpoint of easy production, and an alkyl group having 1 to 15 carbon atoms is particularly preferable. As the organic group for R ² , R ⁵ and R ⁶ , an alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group is particularly preferable.

Specific examples of the divalent organic group include a carbonyl group (—CO—) and an oxy group (—O—) in addition to the divalent organic group obtained by further removing one hydrogen atom from the above monovalent organic group. , A thio group (—S—), an imino group (—NH—), a phosphine diyl group (—PH—), a silylene group (—SiH ₂ —), and the like. These divalent organic groups may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. That is, two or more of these divalent organic groups may be linked. Among these, an alkylene group, an arylene group, a carbonyl group, and an oxy group are preferable from the viewpoint of easy availability of raw materials, and a linear alkylene group having 2 to 12 carbon atoms, a phenylene group, a carbonyl group, and an oxy group are more preferable. From the viewpoint of easy production, the combination of divalent organic groups is preferably a phenyleneoxyalkylene group, a phenylenecarbonyl group, an alkyleneoxyalkylene group, or the like. In particular, as R ³ and R ⁷ in the acid dissociable partial structure (X), a phenylene group, a naphthylene group, a carbonyl group, a phenylenecarbonyl group, a naphthylenecarbonyl group, a phenyleneoxy group which may have a substituent An alkylene group, a phenyleneoxyphenylene group, a naphthyleneoxyalkylene group, and a naphthyleneoxyphenylene group are preferred.

The organic group of R ^{1 to} R ⁷ may have an arbitrary substituent. The substituent that the organic group of R ^{1 to} R ⁷ may have is not particularly limited as long as it does not significantly impair the excellent physical properties of the resist composition of the present invention. Alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, heterocyclic group, alkoxy group, hydroxyl group, amino group, carboxyl group, ester group, halogen atom, thiol group, thioether group, alkoxyphenyl group, organosilicon group, etc. Is mentioned. In addition, these substituents may further have a substituent, and examples of the substituent include the above organic groups having 1 to 20 carbon atoms.
In the present invention, the carbon number of the organic group means the carbon number including the substituent when the organic group further has a substituent.

R ² and R ³ may be connected to each other to form a ring. The ring R ² and R ³ are formed by connecting, including carbon and oxygen atoms between R ² and R ^3, tetrahydropyranyl ring, tetrahydrofuranyl ring, tetrahydropyranyl ring methylene Examples include a ring in which a group is substituted with an oxy group.

R ⁵ and R ⁶ may be connected to each other to form a ring. Examples of the ring and R ⁵ and R ⁶ are formed by connecting, including the carbon atoms between R ⁵ and R ^6, a cyclohexane ring, norbornane ring, and adamantane ring.

[2-2-2. Fullerene skeleton]
The fullerene skeleton contained in the structural unit (I) of the substrate component (A) preferably has a partial structure represented by the following formula (1) from the viewpoint of easy production.

(In the formula ^{(1), C} 1 ~C ¹⁰ represents a carbon atom constituting the fullerene skeleton, ^{C 1} is bonded to ^{R 1} or ^{R 4} in the acid-dissociable moiety (X), ^{C 6} independently -C ¹⁰ are each connected to group ^{(R 20)} represented by the following formula (2).)

(In the formula (2), Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, and R has a hydrogen atom, an alkyl group which may have a substituent, or a substituent. And represents an aryl group or an acid dissociable organic group, and n represents an integer of 1 to 3.)

  “Fullerene” is a carbon cluster having a closed shell structure, and the number of carbon atoms of fullerene is usually an even number of 60 to 130.

Specific examples of fullerene include C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C ₉₆ and higher carbon clusters having more carbon atoms. Can be mentioned. In this specification, a fullerene skeleton having i carbon atoms (where i represents an arbitrary natural number) is appropriately represented by a general formula “C _i ”.

  The “fullerene derivative” described later is a general term for compounds or compositions having a fullerene skeleton. That is, fullerene derivatives include those having a substituent on the fullerene skeleton, those containing a metal or a compound inside the fullerene skeleton, and those having a complex formed with another metal atom or compound.

Although the fullerene skeleton which the structural unit (I) of the base component (A) has is not limited, C ₆₀ or C ₇₀ is preferable, and C ₆₀ is more preferable. Since C ₆₀ and C ₇₀ are obtained as the main product in the production of fullerenes, the advantage that is easily available. That is, the base component (A) _were introduced _{C 60} or _{C 70,} preferably a derivative of _{C 60} or _{C 70,} and more preferably a derivative of _{C 60.} Further, it is preferable in terms of cost is a mixture of derivatives of C ₆₀ derivatives and C _70. In this case, an optional mixing ratio of the derivative of C ₆₀ derivatives and C _70, may be determined from the ranges by the features of the resist composition of the present invention.

Hereinafter, the group (R ²⁰ ) represented by the formula (2) will be described in detail. In R ²⁰ , 1 to 3 hydrogen atoms out of monovalent hydrocarbon groups having 6 to 18 carbon atoms are OR groups (R may be a hydrogen atom or a substituent). An alkyl group, an aryl group which may have a substituent, or an acid dissociable organic group).

Specific examples of the aromatic hydrocarbon group Ar having 6 to 18 carbon atoms to which the OR group is bonded (monovalent Ar group before being substituted with the OR group) include a phenyl group; Vinylphenyl groups such as vinylphenyl group, divinylphenyl group and trivinylphenyl group; pentarenyl group, indenyl group, naphthyl group, azulenyl group, heptaenyl group, biphenylenyl group, as-indacenyl group, s-indacenyl group, acenaphthylenyl group, fluorenyl group And cyclic hydrocarbon groups such as a group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoracenyl group, an acephenanthrylenyl group, an aceantirenyl group, a triphenylenyl group, a pyrenyl group, a chrycenyl group, and a tetracenyl group.
Among these, a phenyl group, a naphthyl group, an anthracenyl group, a phenalenyl group, and a pyrenyl group are preferable from the viewpoint of raw material procurement, and a phenyl group and a naphthyl group are particularly preferable from the viewpoint of ease of synthesis.

The position at which the monovalent hydrocarbon group Ar having 6 to 18 carbon atoms is bonded to C ^{6 to} C ^{10 of the} fullerene skeleton is not limited and is arbitrary. For example, in the case of a group having a naphthalene skeleton From the viewpoint of raw material procurement and ease of synthesis, it is preferable that the bonds are bonded at the β-position. With respect to other hydrocarbon groups Ar, preferred bonding positions can be determined from the above viewpoint.

  In the formula (2), an OR group (R represents a hydrogen atom, an alkyl group which may have a substituent, or a substituent) bonded to an aromatic hydrocarbon group Ar having 6 to 18 carbon atoms. The number n of aryl groups or acid dissociable organic groups that may have is preferably 1 to 3. Usually, from the viewpoint of easy synthesis, the number of OR groups, that is, n is preferably 1. In addition, from the viewpoint of increasing the solubility of the developer and the proton source when irradiated with EUV light or EB, OR is preferable. The number of groups, i.e., n is preferably 2 or 3.

  The position at which the OR group is bonded to the aromatic hydrocarbon group Ar is not limited and is arbitrary, and when there are a plurality of OR groups, the relative positional relationship is also not limited and is arbitrary.

In the base component (A) used in the present invention, the group represented by the formula (2) (that is, R ²⁰ ) is “—C ₆ H ₄ -4-OR”, “—C” from the viewpoint of synthesis. ₆ H ₄ -3-OR "," _{- C 6 H 3 -3,4- (OR} ) 2 "," _{- C 6 H 3 -3,5- (OR} ) 2 "," _- C 6 _{H 2 -} 3,4,5- _{(OR) 3} "," _{- β-C 10 H 6 -6} -OR "phenols such as, catechols, pyrogallols, a group derived from naphthols are particularly preferred.

  Specific examples of R include a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or an acid-dissociable organic group. From the viewpoint of the solubility contrast with respect to, an acid-dissociable organic group is preferred. As the acid dissociable organic group, those exemplified in the description of the structural unit (II) described later can be used. Particularly preferred R includes a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a benzyl group, a 1-methoxyethyl group, a 1-ethoxyethyl group, a trimethylsilyl group, a t-butoxycarbonyl group, a t-butoxycarbonylmethyl group, a tetrahydro group. Examples include a pyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrothiofuranyl group, a norbornyl group, and a methyladamantyl group.

In the base component (A), C ^{6 to} C ¹⁰ of the fullerene skeleton represented by the formula (1) are each independently bonded to a group (R ²⁰ ) represented by the formula (2). R ²⁰ may be groups having the same structure or different structures, but from the viewpoint of easy synthesis, all R ²⁰ bonded to C ^{6 to} C ¹⁰ have the same structure. It is preferably a group.

In the present specification, C ^{1 of the} formula (1) is bonded to R ¹ or R ^{4 in the} acid dissociable partial structure (X), and C ^{6 to} C ¹⁰ are each independently represented by the formula (2). The partial structure bonded to the group (R ²⁰ ) may be referred to as “5-fold addition partial structure”.

Examples of the structure of the fullerene skeleton contained in the structural unit (I) are given below. However, the structure of the fullerene skeleton of the base component (A) used in the present invention is not limited to the following examples.
A 5-addition fullerene skeleton represented by the general formula C _i (R ²⁰ ) ₅ (—R ¹ — or —R ⁴ —) having one 5-addition partial structure on the fullerene skeleton.
A 10-fold addition fullerene skeleton represented by the general formula C _i (R ²⁰ ) ₁₀ (—R ¹ — or —R ⁴ —) ₂ having two 5-fold addition partial structures on the fullerene skeleton.

  Among these, since the production is easy and a single compound can be produced, a pentaaddition fullerene skeleton having one pentaaddition partial structure on the fullerene skeleton is preferable from the viewpoint of easy reaction control. From the standpoint of adhesion to the substrate and improvement in sensitivity during exposure, a 10-fold addition fullerene skeleton is preferred. The structures of the 5-added fullerene skeleton and the 10-added fullerene skeleton have been clarified by Eiichi Nakamura et al. (Non-Patent Documents 1 to 5).

[2-3. Unit (II)]
In the case where the resist composition of the present invention is a positive resist composition, the base component (A) contains, in addition to the structural unit (I), a hydroxyphenyl group, a hydroxynaphthyl group with respect to a repeating unit constituting the polymer main chain. And at least one substituent (Y) selected from the group consisting of a group and a carboxyl group (however, each of these groups may further have a substituent), and the substituent (Y) is an acid A copolymer having the structural unit (II) protected with a dissociable organic group is preferred.
The structural unit (II) may contain two or more substituents (Y) protected with an acid-dissociable organic group, and in that case, the substituents protected with each acid-dissociable organic group The groups (Y) may be the same as or different from each other.
Further, the structural unit (II) includes a substituent other than the substituent (Y), for example, an alkyl group, an alkoxy group, an aryl group, and an aryloxy group (however, these groups each may further have a substituent) You may have.

  As the monomer having a substituent (Y) that can constitute this structural unit (II), hydroxystyrene, acrylic acid, methacrylic acid, or the substituent (Y) of these monomers is an acid-dissociable organic group in advance. Examples include a protected monomer, but from the viewpoint of reaction controllability, the structural unit (II) before being protected with an acid-dissociable organic group is preferably one represented by the following formula (AA), particularly substituted What is represented by the following formula (AAA-1) and the following formula (AAA-2) in which one of the groups is a hydrogen atom (that is, an unsubstituted form) or a methyl group is more preferable.

  Examples of the substituent (Y) include a hydroxyphenyl group, a hydroxynaphthyl group, and a carboxyl group, and a hydroxyphenyl group and a carboxyl group are particularly preferable from the viewpoint of easy availability of raw materials. In the copolymer of the base component (A), these substituents (Y) may contain one kind alone, or two or more kinds in any combination and ratio. Each of these substituents (Y) may further have a substituent. In particular, an acid functional group which is dissociated with an acid is substituted for and protected with respect to an acidic functional group such as a hydroxyl group or a carboxyl group which the substituent (Y) has.

  Here, examples of the acid dissociable organic group include a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, a silyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid dissociable group. Can be mentioned.

Examples of the substituted methyl group include methoxymethyl group, methylthiomethyl group, ethoxymethyl group, ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, bromophenacyl group, and methoxyphenacyl. Group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group , Ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, isopropoxycarbonylmethyl group, n-butoxycarbonylmethyl group, t-butoxy Rubonirumechiru group, and the like can be mentioned.
Examples of the 1-substituted ethyl group include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1- Diethoxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropylethyl group, 1- Phenylethyl group, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-isopropoxycarbonylethyl group, 1-n-butoxycarbonylethyl Group, 1-t-butoxycarbonylethyl group and the like.
Examples of the 1-branched alkyl group include isopropyl group, sec-butyl group, t-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group, and the like. Can do.

Examples of the silyl group include trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, isopropyldimethylsilyl group, methyldiisopropylsilyl group, triisopropylsilyl group, t-butyldimethylsilyl group, methyldiethyl group. -T-butylsilyl group, tri-t-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, triphenylsilyl group and the like can be mentioned.
Examples of the germyl group include a trimethylgermyl group, an ethyldimethylgermyl group, a methyldiethylgermyl group, a triethylgermyl group, an isopropyldimethylgermyl group, a methyldiisopropylgermyl group, a triisopropylgermyl group, Examples thereof include t-butyldimethylgermyl group, methyldi-t-butylgermyl group, tri-t-butylgermyl group, phenyldimethylgermyl group, methyldiphenylgermyl group, and triphenylgermyl group.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, and a t-butoxycarbonyl group.

Examples of the acyl group include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, laurylyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl Group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, canphoroyl group Benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group Isonicotinoyl group, p- toluenesulfonyl group, and mesyl group.
Furthermore, examples of the cyclic acid dissociable group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a 4-methoxycyclohexyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, and a tetrahydro group. Thiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophene-1,1-dioxide group, norbornyl group, isobornyl group, tricyclo A decanyl group, an adamantyl group, a methyladamantyl group, etc. can be mentioned.

  Among these acid dissociable organic groups, t-butyl group, benzyl group, 1-methoxyethyl group, 1-ethoxyethyl group, trimethylsilyl group, t-butoxycarbonyl group, t-butoxycarbonylmethyl group, tetrahydropyranyl group , Tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group, norbornyl group, methyladamantyl group and the like are preferable.

The copolymer of the base component (A) may contain only one kind of these acid dissociable organic groups, or may contain two or more kinds in any combination and ratio.
In addition to the structural unit corresponding to the structural unit (I) or the structural unit (II), the copolymer includes other structural units (for example, ethylene units, propylene units or other α-olefin units, styrene units, (metabolites). ) Acrylic acid alkyl ester unit, alkyl vinyl ether unit, etc.).

[2-4. Content of Structural Unit (I)]
The substrate component (A) contains the structural unit (I) as an essential structural unit, and further contains the structural unit (II) as necessary.

  The ratio of the structural unit (I) contained in the base component (A) is the ratio of the structural unit (I) to all repeating units constituting the polymer main chain of the base component (A) (hereinafter, this ratio is referred to as “configuration In some cases, the unit (I) content ”is generally 0.01 mol% or more and 50 mol% or less, preferably 0.1 mol% or more and 30 mol% or less, more preferably 0.5 mol% or more and 10 mol%. It is as follows. When there is too little content of structural unit (I), there exists a possibility that improvement effects, such as etching tolerance by having introduced fullerene frame | skeleton in base-material component (A), may not fully be acquired, on the other hand, structural unit (I) If the content of is too large, the amount of the expensive fullerene derivative used is large, which increases the cost and may cause a reduction in exposure sensitivity.

[2-5. Content of acid dissociable organic group in structural unit (II)]
When the substrate component (A) contains the structural unit (II), the content of the structural unit (II) is the content of the structural unit (I) or the acid dissociable organic contained in one structural unit (II). Although it depends on the number and type of groups, the molecular weight and polarity of the base component (A), the use of the resist composition, and the required properties, the constituent unit for all repeating units constituting the polymer main chain of the base component (A) The total amount of the acid dissociable organic group and structural unit (I) contained in (II) (hereinafter, this ratio may be referred to as “total acid dissociable group content”), In such a positive resist, the proportion is preferably 10 mol% or more and 100 mol% or less, more preferably 15 mol% or more and 70 mol% or less. On the other hand, in a negative resist in which the unexposed portion is alkali-soluble, the total acid dissociable group content is preferably 0.1 mol% or more and 40 mol% or less, and more preferably 0.1 mol% or more and 20 mol% or less. If the total acid dissociable group content is too small, a sufficient contrast difference in alkali developer solubility due to the introduction of the structural unit (II) cannot be obtained, and if it is too large, the exposure sensitivity may be insufficient.

[2-6. Molecular weight of base component (A)]
The weight average molecular weight (hereinafter referred to as “Mw”) in terms of polystyrene measured by gel permeation chromatography of the base material component (A) is preferably 1,000 to 150,000, more preferably 2,000 to 100. , 000. If the Mw of the substrate component (A) is larger than the above upper limit, fine patterning may be difficult, and if it is smaller than the lower limit, applicability may be lowered.

[2-7. Manufacturing method of substrate component (A)]
The base material component (A) acts, for example, a fullerene derivative (having a vinyl ether group or a tertiary ester-containing haloacetyl group) capable of introducing an acid dissociable partial structure (X) with respect to a hydroxyl group or a carboxyl group of an alkali-soluble resin. It can be produced by a method or copolymerization of a fullerene derivative having both an acid-dissociable partial structure and a polymerization active site with other generally known monomers.

As a method for introducing a fullerene skeleton into an alkali-soluble resin via an acid-dissociable organic group, a general acetalization reaction of a vinyl ether group or an etherification reaction of a haloacetyl group can be employed. A detailed manufacturing method can refer to documents such as PROTECTED GROUPS IN ORGANIC SYNTHESIS (John Wiley & Sons, Inc.).
In addition, regarding the copolymerization of fullerene derivatives having both an acid-dissociable partial structure and a polymerization active site with other monomers, radical polymerization initiators and anionic polymerization are performed depending on the type of monomer and reaction medium. A polymerization initiator such as a catalyst, a coordination anion polymerization catalyst, a cation polymerization catalyst or a polymerization catalyst is appropriately selected, and an appropriate one such as bulk polymerization, solution polymerization, precipitation polymerization, emulsion polymerization, suspension polymerization, bulk-suspension polymerization, etc. It can be carried out by a polymerization method.

A specific manufacturing method will be shown in the synthesis example described later. In the synthesis examples described later, polyhydroxystyrene is used as a polymer having the above-described substituent (Y) as a side chain with respect to the polymer main chain as a raw material polymer. An acid or a copolymer of a monomer constituting the polymer and another monomer can be used. Examples of such monomers include α-olefins such as propylene, alkyl vinyl ethers, aryl vinyl ethers, styrene, and (meth) acrylic acid alkyl esters.
In the synthesis examples described later, such a raw material polymer is reacted with a fullerene derivative to which an acid dissociable partial structure (X) is added, and the side chain of the raw material polymer is reacted with the fullerene via the acid dissociable partial structure (X). A copolymer of the base material component (A) is synthesized by introducing a skeleton and then protecting the substituent (Y) of the raw material polymer with an acid-dissociable organic group.

[2-8. Content of base material component]
In the resist composition of the present invention, the content of the base component (A) whose alkali solubility is changed by the action of an acid includes an acid generator (B), a nitrogen-containing organic compound (C), and a negative resist composition. The crosslinking agent component (E) contained in the case of the product is contained in the resist composition in a preferable range with respect to the base material component (A), and the amount thereof is determined by the organic solvent (D) according to a preferable solid content described later. It is optional in the range adjusted to the density. Specifically, in terms of the balance between the applicability of the resist composition and the performance as a resist, such as sensitivity and pattern formability, 40 to 98% by weight with respect to the total solid content in the resist composition, In particular, it is preferably 50 to 90% by weight. In addition, "solid content" refers to components other than the organic solvent (D) in a resist composition here.

[3. Acid generator (B)]
The acid generator (B) generates an acid by EUV light or EB exposure, and changes the alkali solubility of the base component (A) by its action.

  The acid generator (B) used in the present invention is not particularly limited, and those conventionally proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, glyoxime acid generators, diazomethane acid generators, nitrobenzyl sulfonate acid generators, Examples include imino sulfonate acid generators and disulfone acid generators. Among them, onium salt acid generators and oxime sulfonate acid generators are preferable, onium salt acid generators are more preferable, and sulfonium salt (following formula (3)) or iodonium salt (following formula (4)). The acid generator is preferred.

(In formulas (3) and (4), R ^{8 to} R ¹⁰ each independently represents an organic group having 1 to 20 carbon atoms, and R ¹¹ is a linear, branched or cyclic alkyl group or fluorinated. Represents an alkyl group, R ⁸ and R ⁹ may be bonded to each other to form a ring.)

Examples of the organic group having 1 to 20 carbon atoms of R ^{8 to} R ¹⁰ in formula (3) and R ⁸ and R ⁹ in formula (4) include a linear, branched or cyclic alkyl group, Examples include an alkenyl group, an oxyalkyl group or an oxyalkenyl group, and an aryl group, aralkyl group or aryloxyalkyl group which may have a substituent. Some or all of the hydrogen atoms of these groups may be substituted with alkoxy groups or the like. R ⁸ and R ⁹ may be bonded to each other to form a ring, and when forming a ring, R ⁸ and R ⁹ each represent an alkylene group having 1 to 10 carbon atoms, that is, S ⁺ Or what forms a 3-21 membered ring including I ^<+> is mentioned. R ^{8 to} R ¹⁰ may be the same as or different from each other.

Specific examples of R ^{8 to} R ¹⁰ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, Alkyl groups such as nonyl group, decanyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, adamantyl group; vinyl group, allyl group, propenyl group, Alkenyl groups such as butenyl, hexenyl, and cyclohexenyl; 2-oxycyclopentyl, 2-oxycyclohexyl, 2-oxypropyl, 2-cyclopentyl-2-oxyethyl, 2-cyclohexyl-2-oxyethyl, 2- (4-Methylcyclohexyl)- An oxyalkyl group such as oxyethyl group; an aryl group such as phenyl group and naphthyl group; p-methoxyphenyl group, m-methoxyphenyl group, o-methoxyphenyl group, ethoxyphenyl group, p-tert-butoxyphenyl group, m -Alkoxyphenyl group such as tert-butoxyphenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, ethylphenyl group, 4-tert-butylphenyl group, 4-butylphenyl group, dimethylphenyl Alkylphenyl groups such as groups, alkyl naphthyl groups such as methyl naphthyl groups, ethyl naphthyl groups, dimethyl naphthyl groups and diethyl naphthyl groups, alkoxy naphthyl groups such as methoxy naphthyl groups, ethoxy naphthyl, dimethoxy naphthyl groups and diethoxy naphthyl groups Ally with substituent Groups: aralkyl groups such as benzyl group and phenethyl group (phenylethyl group), 2-phenyl-2-oxyethyl group, 2- (1-naphthyl) -2-oxyethyl group, 2- (2-naphthyl) -2-oxyethyl And 2-aryl-2-oxyalkyl groups such as a group.

  Among these, an aryl group is preferable, and a phenyl group and a naphthyl group are particularly preferable.

R ^{11 in} formula (3) and formula (4) represents a linear, branched or cyclic alkyl group or fluorinated alkyl group. The linear or branched alkyl group usually preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The cyclic alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

  It is preferable that at least a part of hydrogen atoms of these alkyl groups is substituted with fluorine atoms. The substitution rate to the fluorine atom is usually 10 to 100%, preferably 50 to 100%. In particular, a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms is preferred from the viewpoint of increasing the strength (pKa) of the acid.

  As the acid generator (B), one kind of these acid generators may be used alone, or two or more kinds may be used in combination. When combining two or more types, the types and ratios are arbitrary.

  In the present invention, as the acid generator (B), it is particularly preferable to use an onium salt acid generator that gives a fluorinated alkylsulfonic acid ion or a dialkylaryliodonium ion.

  The content of the acid generator (B) in the resist composition of the present invention is usually preferably 1 to 50% by weight with respect to the base component (A) whose alkali solubility is changed by the action of the acid, 40% by weight is more preferred, and 5-30% by weight is most preferred. By setting it as the said range, pattern formation by EUV light or EB exposure is fully performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

[4. Nitrogen-containing organic compound (C)]
The resist composition of the present invention contains a nitrogen-containing organic compound (C) in order to improve the resist pattern shape, the stability over time, and the like in both positive and negative types. As the nitrogen-containing organic compound (C), any one reported so far may be used, but a cyclic amine and an aliphatic amine are preferable. In particular, secondary aliphatic amines and tertiary aliphatic amines are preferred, and tertiary aliphatic amines are most preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and preferably has 1 to 15 carbon atoms.

  Specific examples of the nitrogen-containing organic compound (C) include primary aliphatic alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n Secondary aliphatic alkylamines such as -propylamine, di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, dicyclohexylamine; Trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine , Tertiary aliphatic alkyl such as tri-n-decanylamine and tri-n-dodecylamine Min; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di -n- octanol amine, alkyl alcohol amines such as tri -n- octanol amine.

  Other specific examples include aliphatic monocyclic amines such as piperidine and piperazine; 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0]. And aliphatic polycyclic amines such as -7-undecene, 1,4-diazabicyclo [2.2.2] -octane, and hexamethylenetetramine.

  Among these, a tertiary aliphatic amine having 5 to 10 carbon atoms is preferable, and tri-n-octylamine having 8 carbon atoms is particularly preferable.

  As the nitrogen-containing organic compound (C), one kind of these nitrogen-containing organic compounds may be used alone, or two or more kinds may be used in combination. When combining two or more types, the types and ratios are arbitrary.

  The content of the nitrogen-containing organic compound (C) in the resist composition of the present invention is usually preferably 0.01 to 20% by weight with respect to the base component (A) whose alkali solubility is changed by the action of the acid described above. 0.1 to 10% by weight is more preferable, and 1 to 5% by weight is most preferable. When the content of the nitrogen-containing organic compound (C) is too large, the acid in the resist composition may be excessively captured and the EUV light sensitivity or EB sensitivity may be lowered, and when the content is too small, the acid in the resist composition may be reduced. LER, LWR, and resolution may deteriorate due to insufficient capture.

[5. Organic solvent (D)]
The resist composition of the present invention contains an organic solvent (D) in both positive and negative types. The organic solvent (D) is not particularly limited as long as it dissolves the components to be used to form a uniform solution, and any organic solvent that has been reported so far as an organic solvent for conventional chemically amplified resist compositions is used. can do.

  Specific examples of the organic solvent (D) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol Polyhydric alcohols such as dipropylene glycol; ester compounds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate; monomethyl ethers of the polyhydric alcohols or ester compounds, mono Examples thereof include monoalkyl ethers such as ethyl ether, monopropyl ether, and monobutyl ether.

  In addition, cyclic ethers such as dioxane; methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, Esters such as ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethyl benzene, diethyl benzene, isopropyl benzene, amyl benzene, toluene, xylene, trimethyl benzene, etc. Aromatic organic solvents; amines such as N, N-dimethylacetamide and the like.

  Among these, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, cyclohexanone, and γ-butyrolactone are preferable.

  As the organic solvent (D), one kind of these organic solvents may be used alone, or two or more kinds may be used in combination. When combining two or more types, the types and ratios are arbitrary.

  The amount of the organic solvent (D) used is not particularly limited, but may be appropriately set according to the coating film thickness so that the resist composition of the present invention has a viscosity and concentration that can be applied to a substrate or the like. The organic solvent (D) is used so that the solid content concentration of the resist composition of the present invention is usually 0.5 to 20% by weight, preferably 1 to 10% by weight.

[6. Crosslinking agent component (E)]
When used as a negative resist composition, the resist composition of the present invention preferably contains a crosslinking agent component (E). This crosslinking agent component (E) is not particularly limited, and any crosslinking agent used in conventional chemically amplified negative resist compositions can be used.

  Specific examples of the crosslinking agent component (E) include 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis (hydroxymethyl) norbornane, cyclohexanedimethanol, 3,4,8-tri Hydroxyl such as hydroxytricyclodecane, 3,4,9-trihydroxytricyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane An aliphatic cyclic hydrocarbon having a group or a hydroxyalkyl group, or an oxygen-containing derivative thereof.

  Further, formaldehyde, or formaldehyde and a lower alcohol are reacted with an amino group-containing compound such as melamine, acetoguanamine, benzoguanamine, urea, ethylene urea, propylene urea, glycoluril, and the hydrogen atom of the amino group is converted into a hydroxymethyl group or a lower group. The compound substituted by the alkoxymethyl group etc. is mentioned.

  Among these, those using melamine as an amino group-containing compound are melamine-based crosslinking agents, those using urea, ethylene urea, propylene urea, etc. are urea-based crosslinking agents, and those using glycoluril are glycoluril-based crosslinking agents. That's it. Of these, melamine-based crosslinking agents are particularly preferred.

  Melamine-based crosslinking agents include compounds in which melamine and formaldehyde are reacted to replace the amino group hydrogen atom with a hydroxymethyl group, and melamine, formaldehyde and lower alcohol are reacted to convert the amino group hydrogen atom into lower alkoxymethyl. And a compound substituted with a group. Specific examples include hexamethoxymethyl melanin, hexaethoxymethyl melanin, hexapropoxymethyl melanin, hexabutoxymethyl melanin, etc. Among them, hexamethoxymethyl melanin is preferable.

  As the crosslinking agent component (E), one kind of these crosslinking agent components may be used alone, or two or more kinds may be used in combination. When combining two or more types, the types and ratios are arbitrary.

  The content of the crosslinking agent component (E) in the negative resist composition of the present invention is preferably 1 to 50% by weight with respect to the base material component (A) whose alkali solubility is changed by the action of an acid. 40% by weight is more preferred, and 5-30% by weight is most preferred. By setting it as the above range, the crosslinking reaction with the base material component (A) proceeds sufficiently, a good resist pattern is formed, and the storage stability of the resist composition is good, and the EUV light sensitivity or EB Sensitivity deterioration with time is suppressed.

[7. Method for preparing resist composition]
Although there is no restriction | limiting in the preparation method of the resist composition of this invention, The base material component (A) from which alkali solubility changes with the effect | action of an acid, the acid generator (B) which generate | occur | produces an acid by exposure, a nitrogen-containing organic compound ( C) and an organic solvent (D), and in the case of a negative resist composition, the crosslinking agent component (E) may be prepared by a method of dissolving with stirring in a predetermined apparatus, a method of irradiating ultrasonic waves, or the like. it can. The prepared resist composition may be purified by filtering as necessary.

  In addition, in the resist composition of this invention, in the range which does not impair the objective of this invention, the base material component (A) from which alkali solubility changes with the effect | action of an acid, the acid generator (B) which generate | occur | produces an acid by exposure , Nitrogen-containing organic compound (C) and organic solvent (D), and other components other than the crosslinking agent component (E) used in the negative resist composition, such as surfactants, dissolution inhibitors, plasticizers, stability Agents, colorants, antihalation agents, dyes and the like may be included.

[8. Resist pattern forming method]
The method for forming a resist pattern of the present invention comprises a step of applying a resist composition of the present invention on a substrate to form a resist film, a step of heat-treating the formed resist film, and selectively processing the resist film after the heat treatment. And a step of exposing to EUV light or EB, and a step of developing a resist film after EUV light or EB exposure to form a resist pattern. Note that the exposed resist film may be heat-treated again as necessary before development.

[8-1. Process for forming resist film: coating process]
A resist film can be formed by coating the resist composition of the present invention on a substrate by using any coating method such as spraying, spin coating, dip coating, or roll coating. As a method, a spin coating method is preferable from the viewpoint of forming a uniform thin film.

  There is no restriction | limiting in the board | substrate used as application | coating object, The dimension and shape are arbitrary. Also, although the material of the substrate is not limited, for example, in the manufacturing process of a semiconductor integrated circuit, usually a silicon (Si) substrate, a wide gap semiconductor such as SiC, nitride semiconductor, diamond, or a compound semiconductor such as GaAs or AlGaAs. A substrate is used. In addition, as a thin film material to be processed into a desired pattern by dry etching or the like on a substrate on which a resist film is formed, a polysilicon thin film or a laminated film of a polysilicon thin film and a metal thin film, Al, W, Cu, Mo, etc. Insulator thin films such as metal thin films, Si oxide films, Si nitride films, and Si oxynitride films. An organic film is formed on the thin film material desired to be processed into the desired pattern to have a thickness of 1 nm or more and 30 nm or less, preferably 3 nm or more and 25 nm or less, most preferably 5 nm or more and 20 nm or less, and the resist composition of the present invention is formed thereon. The resist film may be formed.

  Furthermore, a resist film of the resist composition of the present invention may be formed on the surface as an upper layer resist in a so-called multilayer resist structure. A typical multilayer resist structure is an upper layer resist, an intermediate layer, and a lower layer structure from the surface. Alternatively, the number of layers may be further increased as necessary. For example, a coating-type carbon film as a lower layer, an organic Si-based film as an intermediate layer, an organic film as an upper layer, and a resist film of the resist composition of the present invention as an uppermost layer are formed on the desired thin film to be processed. As the lower layer, in addition to the coating type carbon film, a carbon film formed by sputtering, an organic film formed by spin coating and subjected to heat treatment, and the like are also used. As the intermediate layer, an Si oxide film, a Si nitride film, a Si oxynitride film, a spin-on-glass (SOG) film, a TiN film, and the like are used in addition to the organic Si film.

Usually, the resist film thickness when EUV light or EB is used is 10 nm or more and 200 nm or less, preferably 20 nm or more and 100 nm or less, and most preferably 30 nm or more and 80 nm or less. The film thickness is also determined according to the minimum processing dimension of the desired pattern.
If the resist film thickness is too thin, the dimension of the resist pattern tends to vary greatly from the desired dimension, and if it is too thick, the resolution tends to be poor.

[8-2. Step of heating resist film: pre-bake]
The organic solvent contained in the resist film is removed by heating the resist film formed from the resist composition of the present invention. The heating temperature is usually in the range of 70 to 250 ° C., preferably 90 to 150 ° C., for 10 to 300 seconds, preferably 30 to 150 seconds, and more preferably 60 to 100 seconds. If the heating temperature is too low, the organic solvent removal efficiency is poor, and if it is too high, the resist composition may be decomposed. If the heating time is too long, the productivity at the time of production tends to decrease, and if it is too short, the heat is not sufficiently transmitted and the heating effect may vary.

[8-3-1. Selective EUV exposure process]
An EUV exposure source for extracting EUV light from plasma generated by irradiating a target such as Sn, its compound, Xe, etc., called a laser beam to the resist film after the organic solvent is removed by heating; An EUV exposure source for extracting EUV light from plasma generated by discharge with Sn, its compound, Xe being present in the vicinity of the electrode, which is called W, SiC, etc .; with laser light as a target Exposure is performed through a desired mask pattern using a light source such as an EUV exposure source that extracts EUV light from plasma generated by irradiation and discharge; or an EUV exposure source that extracts EUV light from a radiation light source. In order to extract EUV light from the light source of each of the above EUV exposure sources, a reflection type or transmission type filter is used.
At this time, the dimension of the resist pattern formed after development varies depending on the exposure amount. The exposure amount is preferably an exposure amount having a desired dimension, but the exposure amount within ± 10% is preferable with respect to the desired size, and the exposure amount within ± 5% is particularly preferable. At this time, the exposure amount having a desired dimension may be referred to as sensitivity in each pattern dimension.

[8-3-2. Selective EB exposure process]
The resist film from which the organic solvent has been removed by heating is irradiated with an electron beam (EB) emitted from an electron gun to draw and expose a desired pattern. The EB acceleration voltage is preferably 1 to 200 kV, more preferably 10 to 150 kV, and particularly preferably 30 to 125 kV. By setting it as the said range, high-resolution pattern formation and high productivity are securable.

[8-4. Reheating process: Post exposure bake]
The film after selective EUV light or EB exposure may be heated as necessary to effectively diffuse the acid generated by exposure into the resist film. The heating temperature in this case is usually in the range of 70 to 200 ° C., preferably 80 to 150 ° C., for 10 to 300 seconds, preferably 30 to 150 seconds, more preferably 60 to 100 seconds. If the heating temperature is too low, the acid diffusion efficiency may be poor and the sensitivity may be lowered. If the heating temperature is too high, the acid diffusion efficiency may be too high, and good resolution, LER, and LWR may not be obtained. If the heating time is too long, the productivity at the time of production tends to decrease, and if it is too short, the heat is not sufficiently transmitted and the heating effect may vary.

[8-5. Development process]
A resist pattern can be formed by developing the film subjected to the above-described process using an alkali developer.

Examples of the alkali developer include alkaline aqueous solutions such as tetramethylammonium hydroxide (TMAH) and tetrabutylammonium hydroxide (TBAH). The TMAH concentration is usually 0.1 to 10% by weight, preferably 1 to 5% by weight. More preferably, the development is performed using a 2 to 3 wt% aqueous solution for 10 to 180 seconds, preferably 20 to 120 seconds, by a conventional method such as an immersion method, a paddle method, or a spray method.
Other arbitrary compounds such as a surfactant may be contained in the developer as long as the excellent characteristics of the resist pattern forming method of the present invention are not significantly impaired.
After alkali development, a washing process with pure water is usually performed.

  Note that the present invention is characterized by EUV light or EB exposure, and fine patterning with a smaller resolution is possible than using other currently developed exposure sources.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and may be arbitrarily modified without departing from the gist of the present invention. be able to.

[Synthesis Example 1: Synthesis of Polymer (A1) Introducing Fullerene Derivative]

<Synthesis of Raw Material Fullerene Derivative: [C ₆₀ ] (4-OMe-C ₆ H ₄ ) ₅ ((CH ₂ ) ₁₁ OCH═CH ₂ )>

Potassium t-butoxide (2.39 mmol) was added at 25 ° C. to a tetrahydrofuran suspension (80 mL) of [C ₆₀ ] (4-OMe—C ₆ H ₄ ) ₅ H (2.00 g 1.59 mmol). After stirring for 20 minutes at the same temperature, the reaction solution changed to a black homogeneous solution. Subsequently, 1-bromo-11- (vinyloxy) -undecane (3.18 mmol) was added, heated to reflux temperature, and stirred for 20 hours. Thereafter, the reaction was stopped with ion-exchanged water (0.1 mL), and the reaction solvent was removed by an evaporator. The solution was passed through flash chromatography using silica gel (eluent: toluene: ethyl acetate: triethylamine = 100: 5: 1), and the eluent was removed by an evaporator. Thereafter, a solution obtained by dissolving the obtained solid in 10 mL of toluene was added dropwise to 400 mL of methanol to perform crystallization. As a result, the title compound was obtained as a red solid (1.97 g, 1.36 mmol, 85% yield). The instrumental analysis data of the fullerene derivative obtained is shown below.

¹ H NMR (400 Hz solvent: CDCl ₃ ): 0.8 to 1.8 (m, ₂₀ H, [C ₆₀ ] —C ₁₀ H ₂₀ ), 3.72 (t, 2 H, C H ₂ OCH═CH ₂ ) , 3.75 (s, 3H, OC H ₃ ), 3.80 (s, 12H, OC H ₃ ), 4.01 (d, 1H, CH ₂ OCH═C H ₂ ), 4.19 (d, _{1H, CH 2 OCH = C H} 2), 6.49 (dd, 1H, CH 2 O CH = CH 2), 6.68 (d, 2H, C 6 H 4), 6.83 (d, 8H, _{C 6 H 4), 7.26 (} d, 2H, C 6 H 4), 7.65 (dd, 8H, C 6 H 4)

As a result of HPLC measurement of the obtained toluene solution of the fullerene derivative under the following conditions, a peak of 94% (Area%) was observed at a retention time of 9.7 min.
Column type: ODS
Column size: 150mm x 4.6mmφ
Eluent: Toluene / methanol = 3/7
Detector: UV290nm

Moreover, the following results were obtained by performing LC-MASS measurement under the following conditions.
APCI-MS (-) (eluent: toluene / methanol = 25/75): m / z = 1452.4 (M -)

<Synthesis of Intermediate Polymer (a1)>

Polyhydroxystyrene (VP-2500 Mw: 4200 manufactured by Nippon Soda Co., Ltd.) (0.15 g, 1.2 mmol (monomer conversion)), p-toluenesulfonic acid (21 mg 0.12 mmol), molecular sieves 4A (0.3 g) ), Dehydrated tetrahydrofuran (THF) (7.5 mL), [C ₆₀ ] (4-OMe—C ₆ H ₄ ) ₅ ((CH ₂ ) ₁₁ OCH═CH ₂ ) (0.54 g 0.37 mmol) at 25 ° C. And stirred at reflux temperature for 6 hours. Thereafter, the reaction was stopped with triethylamine (0.1 mL), and the organic layer was extracted by a liquid separation operation of ethyl acetate / water. The organic layer was washed with ion-exchanged water three times and dried with sodium sulfate, and then the solvent was removed by an evaporator. Then, the title compound (0.16g) was obtained as a result of performing crystallization by dripping the solution which melt | dissolved the target object in 1 mL of ethyl acetate in 300 mL of toluene. The hydroxyl group protection rate of the resulting product was determined by ¹ H-NMR measurement to be 98% OH groups and 2% fullerene vinyl ether groups. The instrumental analysis data of the polymer (a1) obtained are shown below.

¹ H NMR (400 Hz solvent: DMSO-d ₆ ): 5.1 to 5.4 (br, C ₆ H ₄ OC H (CH ₃ ) OCH ₂ ), 6.0 to 6.8 (br, C ₆ H ₄ O), 8.7-9.2 (br, C ₆ H ₄ O H ).

<Synthesis of target polymer (A1)>
Polymer (a1) (0.16 g), di-t-butyl dicarbonate (94 mg), THF (10 mL), triethylamine (0.5 mL), 4-dimethylaminopyridine (10 mg) were added at 25 ° C, and 5 at 25 ° C was added. Stir for hours. Thereafter, the reaction was stopped with ion-exchanged water (1 mL), and the organic layer was extracted by a liquid separation operation of ethyl acetate / water. The organic layer was washed with ion-exchanged water three times and dried with sodium sulfate, and then the solvent was removed by an evaporator. Then, the title compound (0.19g) was obtained as a result of performing crystallization by dripping the solution which melt | dissolved the target object in ethyl acetate 1mL in hexane 300mL. When the protection rate of the hydroxyl group of the obtained product was determined by ¹ H-NMR measurement, it was 48% OH group, 2% fullerene vinyl ether group, and 50% t-butoxycarbonyl group (containing structural unit (I)) Rate 2 mol%, total acid dissociable group content 52%).
The instrumental analysis data of the obtained polymer (A1) is shown below.

¹ H NMR (400 Hz solvent: DMSO-d ₆ ): 1.0 to 1.5 (br, Boc) 5.2 to 5.4 (br, C ₆ H ₄ OC H (CH ₃ ) OCH ₂ ), 6 .1 to 7.0 (br, C ₆ H ₄ O), 8.8 to 9.2 (br, C ₆ H ₄ O H )

[Synthesis Example 2: Synthesis of polymer (Z1) not containing fullerene skeleton]

Polyhydroxystyrene (VP-2500 average molecular weight 4200 manufactured by Nippon Soda Co., Ltd.) (2.00 g, 16.5 mmol (monomer conversion)), di-t-butyl dicarbonate (1.62 g), THF (100 mL), triethylamine ( 1 mL) and 4-dimethylaminopyridine (0.3 g) were added at 25 ° C., and the mixture was stirred at 25 ° C. for 9 hours. Thereafter, the reaction was stopped with ion-exchanged water (10 mL), and the organic layer was extracted by an ethyl acetate / water separation operation. The organic layer was washed with ion-exchanged water three times and dried with sodium sulfate, and then the solvent was removed by an evaporator. Thereafter, crystallization was performed by adding 400 mL of hexane to a solution in which the target product was dissolved in 5 mL of ethyl acetate. As a result, the title compound (1.75 g) was obtained. When the protection rate of the hydroxyl group of the obtained product was determined by ¹ H-NMR measurement, it was 48% OH group and 52% t-butoxycarbonyl group.
The instrumental analysis data of the polymer (Z1) obtained are shown below.

¹ H NMR (400 Hz solvent: DMSO-d ₆ ): 1.0 to 1.5 (br, Boc), 6.1 to 7.1 (br, C ₆ H ₄ O), 8.8 to 9.2 (Br, C ₆ H ₄ O H )

[Example 1, Comparative Example 1]
<Preparation of positive resist composition>
The polymer (A1) and 4,4′-di-t-butylphenyliodonium nonafrolate (“BBI-109” manufactured by Midori Kagaku Co., Ltd.) as the photoacid generator (B) were added to the polymer (A1). 3% by weight of tri-n-octylamine as the nitrogen-containing organic compound (C) with respect to the polymer (A1), and perfluoro-containing acrylic oligomer ("Megafac R-30" manufactured by DIC Corporation) as the surfactant. )) With respect to the polymer (A1) in an amount of 0.1% by weight was mixed with the mixed solvent propylene glycol monomethyl ether acetate / cyclohexanone (weight ratio 95/5), which is the organic solvent (D), at 2.40. The positive resist composition (1) of the present invention was prepared by dissolving in a solid content concentration of wt% and filtering this through a 0.2 μm filter ( Example 1).
Further, a positive resist composition (2) of Comparative Example was prepared in the same manner as described above except that the polymer (Z1) was used instead of the polymer (A1) (Comparative Example 1).

<Evaluation of etching resistance of positive resist composition>
After the resist pattern was formed by the following procedure using the positive resist compositions (1) and (2), the etching resistance was evaluated by the following method.

<Formation of resist pattern>
(1) The resist compositions (1) and (2) were spin-coated on a Si substrate to a thickness of 80 nm under conditions of 600 rpm for 4 seconds and 2000 rpm for 30 seconds (application process), 110 ° C. For 90 seconds (pre-bake).
(2) EB exposure apparatus: JBX-6000FS (manufactured by JEOL Ltd.) was used to perform pattern exposure at 400 μC / cm ² at an acceleration voltage of 50 kV (exposure process).
(3) The EB-exposed film was heat-treated at 110 ° C. for 90 seconds (post-exposure baking).
(4) As a developer, an alkali developer having a TMAH concentration of 2.38% by weight (“MF622” manufactured by Shipley) was used and immersed for 30 seconds (development process). Thereafter, pure water was used as a rinse solution, and the developer was rinsed off by immersing in pure water for 30 seconds (cleaning step).

<Etching resistance evaluation>
(I) After pattern formation, the resist film thickness was measured. The film thickness was measured using “Alpha Step 500” manufactured by KLA Tencor.
(Ii) Samples were prepared for each required time in the following manner, each etched, and the resist film thickness was measured.
(RIE etching with CF ₄ gas)
Equipment: RIE-10NR manufactured by Samco International
Etching conditions: CF ₄ , 50 W, 70 sccm, 20 Pa
Etching time: 0 seconds, 60 seconds, 120 seconds, 180 seconds, 240 seconds,
300 seconds, 360 seconds (iii) The etching rate of the resist film is calculated from the slope of the graph of the etching time and the film thickness, and the improvement rate of the etching rate of the resist composition (2) with respect to the etching rate of the resist composition (1) Was calculated.

  The results are shown in Table 1.

As can be seen from Table 1, by using the resist composition of the present invention, a significant improvement in etching resistance is recognized.
The resist composition of the present invention has a high radical scavenging (trapping) performance due to the introduction of the fullerene skeleton, and the generation of outgas during exposure is small.

Claims (11)

It contains a base material component (A) whose alkali solubility is changed by the action of an acid, an acid generator (B) that generates an acid upon exposure, a nitrogen-containing organic compound (C), and an organic solvent (D). Resist composition for exposure to extreme ultraviolet light and electron beam.
However, the base material component (A) has an acid dissociable partial structure (X) represented by either the following (X ¹ ) or (X ² ) with respect to the repeating unit constituting the polymer main chain. A polymer having a structural unit to which a fullerene skeleton is linked (hereinafter referred to as “structural unit (I)”).

(Wherein, ^{R 2} represents an organic group or a hydrogen atom having 1 to 20 carbon ^atoms, R ^1, R 3 ^{~R 6} each independently represent an organic group having 1 to 20 carbon atoms, ^{R 7} represents a single bond or Represents an organic group having 1 to 20 carbon atoms, which may have an arbitrary substituent, and R ² and R ³ , R ⁵ and R ⁶ are bonded to each other to form a ring; In (X ¹ ), R ¹ is bonded to the fullerene skeleton, R ³ is bonded to a repeating unit constituting the polymer main chain, and in (X ² ), R ⁴ is bonded to the fullerene skeleton, R ⁷ is bonded to a repeating unit constituting the polymer main chain.)   A positive resist composition comprising, as a base component (A), an alkali-insoluble or alkali-insoluble polymer protected with an acid-dissociable organic group, which becomes alkali-soluble when the acid-dissociable organic group is dissociated The resist composition for extreme ultraviolet light and electron beam exposure according to claim 1, wherein the resist composition is an object.   The base component (A) is a hydroxyphenyl group, a hydroxynaphthyl group, and a carboxyl group (provided that each of these groups further has a substituent, with respect to the structural unit (I) and the repeating unit constituting the polymer main chain. A structural unit (hereinafter referred to as “structural unit”) having at least one substituent (Y) selected from the group consisting of (which may be present) and wherein the substituent (Y) is protected by an acid-dissociable organic group The resist composition for extreme ultraviolet light and electron beam exposure according to claim 2, wherein the resist composition is called (II) ”.   The resist composition for extreme ultraviolet light and electron beam exposure according to claim 1, further comprising a negative resist composition containing a crosslinking agent component (E). The resist composition for extreme ultraviolet light and electron beam exposure according to any one of claims 1 to 4, wherein the fullerene skeleton has a partial structure represented by the following formula (1).

(In the formula ^{(1), C} 1 ~C ¹⁰ represents a carbon atom constituting the fullerene skeleton, ^{C 1} is bonded to ^{R 1} or ^{R 4} in the acid-dissociable moiety (X), ^{C 6} independently -C ¹⁰ are each bound to the group represented by the following formula (2).)

(In the formula (2), Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, and R has a hydrogen atom, an alkyl group which may have a substituent, or a substituent. Represents an aryl group or an acid dissociable organic group, and n represents an integer of 1 to 3.) R ³ and / or R ^{7 in the} acid dissociable partial structure (X) may have a substituent, phenylene group, naphthylene group, carbonyl group, phenylenecarbonyl group, naphthylenecarbonyl group, phenyleneoxyalkylene The extreme ultraviolet ray according to any one of claims 1 to 5, which is at least one selected from the group consisting of a group, a phenyleneoxyphenylene group, a naphthyleneoxyalkylene group, and a naphthyleneoxyphenylene group. Resist composition for light and electron beam exposure.   The ratio of said structural unit (I) in all the repeating units which comprise the polymer principal chain of a base material component (A) is 0.1 mol% or more and 30 mol% or less, In any one of Claims 1-6 characterized by the above-mentioned. The resist composition for extreme ultraviolet light and electron beam exposure as described.   The resist composition for extreme ultraviolet light and electron beam exposure according to any one of claims 1 to 7, wherein the acid generator (B) is an onium salt acid generator. 9. The onium salt acid generator is a sulfonium salt acid generator represented by the following formula (3) and / or an iodonium salt acid generator represented by the following formula (4). The resist composition for extreme ultraviolet light and electron beam exposure as described.

(In formulas (3) and (4), R ^{8 to} R ¹⁰ each independently represents an organic group having 1 to 20 carbon atoms, and R ¹¹ is a linear, branched or cyclic alkyl group or fluorinated. Represents an alkyl group, R ⁸ and R ⁹ may be bonded to each other to form a ring.)   The resist composition for extreme ultraviolet light and electron beam exposure according to any one of claims 1 to 9, wherein the nitrogen-containing organic compound (C) is a tertiary aliphatic amine.   A process of forming a resist film by applying the resist composition for extreme ultraviolet light and electron beam exposure according to any one of claims 1 to 10 on a substrate, a process of heat-treating the resist film, the resist film A resist pattern forming method characterized by comprising a step of selectively exposing the resist film to extreme ultraviolet light or an electron beam and a step of developing the resist film after the exposure to form a resist pattern.