JP5711958B2 - Pattern formation method - Google Patents

Description

  In the present invention, after forming a positive resist pattern using one or more kinds of chemically amplified positive resist compositions, a pattern reversal composition is applied thereon to form a pattern reversal film, The present invention relates to a pattern forming method for forming a pattern in which an image of the positive resist pattern is reversed on the pattern reversal film by performing organic solvent development.

A technique (pattern formation technique) for forming a fine pattern on a support and etching the lower layer of the pattern by using this as a mask has been widely adopted in the manufacture of IC devices in the semiconductor field, Has attracted attention.
The fine pattern is usually made of an organic material, and is formed by a technique such as a lithography method or a nanoimprint method. For example, in a lithography method, a resist film made of a resist material is formed on a support such as a substrate, and the resist film is subjected to selective exposure with radiation such as light or an electron beam, followed by development processing. Thus, a step of forming a resist pattern having a predetermined shape on the resist film is performed. And a semiconductor element etc. are manufactured through the process of processing a board | substrate by an etching using the said resist pattern as a mask. A resist material in which the solubility of the exposed portion in the developer increases is referred to as a positive type, and a resist material in which the solubility of the exposed portion in the developer decreases is referred to as a negative type.
In recent years, pattern miniaturization is rapidly progressing due to the advancement of lithography technology. As a technique for miniaturizing a resist pattern, the exposure light source is generally shortened in wavelength. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but now mass production of semiconductor elements using KrF excimer laser and ArF excimer laser has been started. Lithography using an ArF excimer laser enables pattern formation with a resolution of 45 nm level. In addition, in order to further improve the resolution, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.
Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition containing an acid generator that generates an acid upon exposure is used. In general, the chemically amplified resist composition is mixed with a base material component whose solubility in an alkaline developer is changed by the action of an acid, together with the acid generator. For example, as a base material component of a positive chemically amplified resist, a material whose solubility in an alkaline developer is increased by the action of an acid is used (for example, see Patent Document 1).
Resin is mainly used as a base material component of the chemically amplified resist composition.

As one of the methods for further improving the resolution, exposure (immersion exposure) is performed by interposing a liquid (immersion medium) having a higher refractive index than air between the objective lens of the exposure machine and the sample. A so-called immersion lithography (hereinafter referred to as “immersion exposure”) is known (for example, see Non-Patent Document 1).
According to immersion exposure, even when a light source having the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and the depth of focus can be reduced. It is said that there is no decline. In addition, immersion exposure can be performed by applying an existing exposure apparatus. For this reason, immersion exposure is expected to be able to form resist patterns with low cost, high resolution, and excellent depth of focus. In particular, in terms of lithography characteristics such as resolution, the semiconductor industry is attracting a great deal of attention.
Immersion exposure is effective in forming all pattern shapes, and can be combined with super-resolution techniques such as the phase shift method and the modified illumination method that are currently being studied. Currently, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. Currently, water is mainly studied as an immersion medium.

One recently proposed lithography technique is a double patterning process in which a resist pattern is formed by performing patterning twice or more (see, for example, Non-Patent Documents 2 to 3).
There are several types of double patterning processes. For example, (1) a method of forming a pattern by repeating a lithography step (from application of a resist composition to exposure and development) and an etching step twice or more, and (2) a lithography step There is a method of repeating the above twice or more.
Formation of the pattern by the method (1) is performed, for example, according to the following procedure. First, a laminate in which a substrate, an underlayer film, and a hard mask are laminated is prepared. Next, a resist film is provided on the hard mask, and the resist film is selectively exposed through a photomask and developed, whereby a plurality of resist patterns of a predetermined size are arranged at predetermined positions. One resist pattern is formed. Next, after etching the hard mask using the first resist pattern as a mask, the remaining first resist pattern is removed. Thereby, a hard mask to which the first resist pattern is transferred is obtained. Next, a resist composition is applied on the hard mask to form a resist film that fills the gaps in the hard mask. Then, the resist film is selectively exposed through a photomask having a different pattern arrangement and developed to form a second resist pattern. Next, after etching the hard mask using the second resist pattern as a mask, the remaining second resist pattern is removed. Thereby, a hard mask to which the first resist pattern and the second resist pattern are transferred is obtained. By performing etching using this hard mask as a mask, the pattern of the hard mask is transferred to the lower layer film, and as a result, a pattern having a narrower pitch than the photomask used is formed.
In the method (2), for example, a first resist film is formed on a support, and a plurality of resist patterns (first resist patterns) are formed by patterning the first resist film. A second resist material is applied thereon to form a second resist film that fills the gaps between the plurality of resist patterns, and the second resist film is patterned.
According to these double patterning processes, even if a light source having the same exposure wavelength is used or the same resist composition is used, the resolution is higher than that in the case of forming in one lithography process (single patterning). It is possible to form a resist pattern. The double patterning process can be performed using an existing exposure apparatus.

  Further, as a recently proposed lithography technique, there is a resin having a repeating unit having a structure having an acid labile group that is eliminated by an acid, and being soluble in an alkali developer by the elimination of the acid labile group. A composition for forming a chemically amplified positive resist film, comprising a photoacid generator that generates an acid upon exposure to high energy rays, a thermal acid generator that generates an acid upon heating, and an organic solvent. A step of obtaining a positive type pattern, exposing or heating the positive type pattern obtained in the step and removing the acid labile group of the resin in the positive type pattern by acid or heat to dissolve the alkali And by forming a crosslink in the resin in such a range that the solubility in an alkaline wet etching solution is not lost, the organic solution used in the composition for forming a film for reversal in the positive pattern is formed. Using positive / negative reversal, including a step of imparting resistance to the above, a step of forming a reversal film using a composition for forming a reversal film, and a step of dissolving and removing the above-mentioned cross-linked positive pattern with an alkaline wet etching solution A pattern forming method has been proposed (see Patent Document 2).

JP 2003-241385 A JP 2009-211036 A

Proceedings of SPIE, 5754, 119-128 (2005). Proceedings of SPIE, 5256, 985-994 (2003). Proceedings of SPIE, 6153, 615301-1-19 (2006).

When a space pattern or hole pattern is formed on a resist film, light that is forced to form a pattern under a weak light incident intensity compared to the case of forming a line pattern or dot pattern, and is incident on an exposed area and an unexposed area, respectively. The contrast of intensity is small. For this reason, the resolution and lithography margin in resist pattern formation (for example, allowance for exposure dose (EL margin), allowance for depth of focus (DOF margin), pattern shape verticality, etc.) are likely to be limited, and high resolution is achieved. It tends to be difficult to form an image resist pattern.
As a technique capable of forming a high-resolution resist pattern, it is conceivable to use a double patterning process as described above. However, among the double patterning processes as described above, in the method (1), in order to form a pattern on the substrate, the resist film is patterned (resist film formation, exposure, development) at least twice. For example, it is necessary to perform etching of the underlying hard mask at least twice, which increases the number of processes, the amount of chemicals used, and the associated increase in manufacturing costs.
The method (2) is suitable for forming a line and space pattern, but is not suitable for forming an isolated space pattern (trench pattern) or a hole pattern.

Moreover, in the pattern formation method described in Patent Document 2, it is necessary to newly provide an exposure step for generating an acid from a photoacid generator after obtaining a positive pattern. Further, when a thermal acid generator is used, in the formation of a positive pattern (first resist pattern), the contrast is weakened due to the influence of the acid generated from the thermal acid generator by post-exposure heating, and the resolution is lowered. There is a risk of causing problems such as inability to form a pattern.
Further, since Patent Document 2 is a method in which a composition for forming a reversal film is applied to a positive resist pattern and then developed using an alkaline wet etching solution, the positive resist pattern and the reversal film forming process are used. It is necessary to use the difference in deprotection energy in the pattern reversal film formed using the composition. In particular, when the deprotection energy of the positive resist pattern is high, the deprotection reaction of the positive resist pattern may be insufficient, and a reverse pattern in which the positive resist pattern is selectively removed is formed. May be difficult.

Therefore, there is a need for a novel technique that can form a pattern such as a space pattern and a hole pattern with a high resolution with a simple method with as few steps as possible.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the pattern formation method useful for formation of a fine pattern.

  In order to solve the above problems, the present invention employs the following configuration.

［式（ｆ２−０−１）中、Ｑは２価の連結基又は単結合であり、Ｒ ^５ はフッ素化アルキル基である。式（ｆ２−０−２）中、Ｑ及びＲ ^５ はいずれも前記と同じである。式（ｆ２−０−３）中、Ｒ ^５１ ，Ｒ ^５２ はそれぞれ独立して水素原子、炭素数１〜５の低級アルキル基、フッ素原子、又は炭素数１〜５のフッ素化低級アルキル基であり、ｍ _ｆ ，ｎ _ｆ はそれぞれ独立して０〜５の整数（ただし、ｍ _ｆ ＋ｎ _ｆ ≧１）であり、ｑ’は０〜５の整数である。］
That is, the pattern forming method of the present invention includes a step (1) of forming a positive resist pattern on a support with one or a plurality of positive resist compositions whose solubility in an alkaline developer is increased by exposure; A process of forming a pattern reversal film by applying a pattern reversal composition containing an organic solvent (S) that does not dissolve the positive resist pattern on the support on which the positive resist pattern is formed (2) And developing the pattern reversal film using an organic solvent developer that dissolves the positive resist pattern, thereby removing the positive resist pattern and forming a resist pattern (3); a pattern forming method comprising, the positive resist composition, an acid generator component that generates acid on exposure (B), and acid-decomposable group The pattern reversal composition contains a substrate component (A ″) that is compatible with the organic solvent (S), and the acid decomposability of (A). The base component (A ″) does not include an acidic compound that decomposes a group, and the polar component includes a hydroxyl group, a cyano group, a carboxy group, a group represented by the following general formula (f2-0-1), Resin having a structural unit (a ″ 1) containing at least one selected from the group consisting of a group represented by the formula (f2-0-2) and a group represented by the following general formula (f2-0-3) And the solubility of the pattern reversal film in the organic solvent developer during development in the step (3) is smaller than the solubility of the positive resist pattern in the organic solvent developer. To do.

[In formula (f2-0-1), Q represents a divalent linking group or a single bond, and R ⁵ represents a fluorinated alkyl group. In formula (f2-0-2), Q and R ⁵ are the same as described above. In formula (f2-0-3), R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms. , M _f and n _f are each independently an integer of 0 to 5 (where m _f + n _f ≧ 1), and q ′ is an integer of 0 to 5. ]

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
The “structural unit” means a monomer unit (monomer unit) constituting a polymer compound (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

“(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.
“(Meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.
“(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

    ADVANTAGE OF THE INVENTION According to this invention, the pattern formation method useful for formation of a fine pattern can be provided.

It is each process figure of the resist pattern formation method in this invention.

≪Pattern formation method≫
The pattern forming method of the present invention comprises a step (1) of forming a positive resist pattern on a support with one or a plurality of positive resist compositions whose solubility in an alkali developer increases upon exposure; (2) forming a pattern reversal film by applying a pattern reversal composition containing an organic solvent (S) that does not dissolve the positive resist pattern on the support on which a mold resist pattern is formed; And (3) forming the resist pattern by developing the pattern reversal film using an organic solvent developer that dissolves the positive resist pattern to remove the positive resist pattern. .
Hereinafter, each step will be described in more detail with reference to FIG.

[Step (1)]
First, the positive resist pattern 2 is formed on the support 1 by using one or a plurality of positive resist compositions whose solubility in an alkaline developer is increased by exposure.
The support 1 is not particularly limited, and a conventionally known one can be used. For example, a substrate for an electronic component or a substrate on which a predetermined wiring pattern is formed can be exemplified. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support 1 may be a substrate in which an inorganic and / or organic film is provided on the substrate as described above. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC) and a lower layer film in a multilayer resist method. In particular, it is preferable to provide an organic film because a pattern with a high aspect ratio can be formed on the substrate, which is useful in manufacturing semiconductors.
Here, the multilayer resist method is a method in which at least one organic film (lower film) and at least one resist film are provided on a substrate, and the lower layer is patterned using the resist pattern formed on the upper resist film as a mask. It is said that a high aspect ratio pattern can be formed. In the multilayer resist method, basically, a method having a two-layer structure of an upper resist film and a lower film, and one or more intermediate layers (metal thin film, etc.) are provided between the resist film and the lower film. And a method of forming a multilayer structure of three or more layers. According to the multilayer resist method, by securing a required thickness with the lower layer film, the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
The inorganic film can be formed, for example, by coating an inorganic antireflection film composition such as a silicon-based material on a substrate and baking.
The organic film is formed by, for example, applying an organic film forming material in which a resin component or the like constituting the film is dissolved in an organic solvent to a substrate with a spinner or the like, preferably 200 to 300 ° C., preferably 30 to 300 seconds, More preferably, it can be formed by baking under heating conditions of 60 to 180 seconds.

The positive resist pattern 2 in the step (1) can be formed by a conventionally known method, and can be formed by applying a positive resist composition whose solubility in an alkali developer increases by exposure on a support.
The positive resist composition is not particularly limited, and can be appropriately selected from known chemical amplification type positive resist compositions.
Here, the “chemically amplified resist composition” contains an acid generator component that generates an acid upon exposure as an essential component, and an alkali of the entire chemically amplified resist composition by the action of the acid. It has the property of changing the solubility in a developer. For example, in the case of a positive type, the solubility in an alkali developer increases.
The positive resist composition in the step (1) preferably contains an acid generator component (B) that generates an acid upon exposure and a base material component (A) having an acid-decomposable group. When exposure and post-exposure baking are performed on a resist film formed using this positive resist composition, the acid of the base component (A) is produced by the action of the acid generated from the acid generator component (B). Degradable groups are decomposed.

Here, the “acid-decomposable group” is an acid decomposition that can break at least a part of the bond in the structure of the acid-decomposable group by the action of an acid generated from the acid generator component (B) by exposure. It is a group having properties. The acid-decomposable group is decomposed by the action of an acid to generate a polar group, so that the polarity is increased. Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (—SO ₃ H). Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as OH-containing polar group) is preferable, and a carboxy group or a hydroxyl group is more preferable.
More specifically, examples of the acid-decomposable group include a group obtained by protecting the polar group with an acid dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is substituted with an acid dissociable group).
The “acid-dissociable group” is capable of cleaving at least a bond between an acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid generated from the acid generator component (B) by exposure. It is a group having acid dissociability. The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than a polar group generated by dissociation of the acid-dissociable group. Dissociates, and a polar group having a polarity higher than that of the acid-dissociable group is generated to increase the polarity.
As a result, the polarity of the entire base component (A) increases. By increasing the polarity, the solubility in an alkaline developer is relatively increased if an alkaline development process is applied. On the other hand, if a solvent development process is applied, the solubility in an organic developer containing an organic solvent is relatively reduced.

  In the step (1), this acid-decomposable group has an alkali dissolution inhibiting property that makes the entire base component (A) difficult to dissolve in an alkali developer before decomposition, and the acid generator component (B). The acid-decomposable group is decomposed by the action of the acid generated from the resin, and the decomposition of the acid-decomposable group increases the solubility of the substrate component (A) in the alkaline developer. Therefore, when selective exposure and post-exposure baking are performed on a resist film formed using the positive resist composition, the exposed portion of the resist film acts as an acid generated from the acid generator component (B). As a result, the solubility in an alkali developer increases while the solubility in an unexposed portion does not change in the alkali developer. Therefore, only the exposed portion is dissolved and removed by alkali development, and a positive resist pattern 2 is formed. The positive resist composition used for forming the positive resist pattern 2 in the step (1) will be described in detail later.

The positive resist composition can be applied by a conventionally known method using a spinner or the like.
Specifically, the positive resist composition is applied onto a support with a spinner or the like, and is baked (pre-baked) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. The resist film can be formed by volatilizing the organic solvent.
The thickness of the resist film is preferably 50 to 500 nm, more preferably 50 to 450 nm. By setting it within this range, there are effects that a resist pattern can be formed with high resolution and sufficient resistance to etching can be obtained.

The patterning in the step (1) can be performed by using a conventionally known method. For example, the resist film is selectively exposed through a mask (mask pattern) on which a predetermined pattern is formed. Bake treatment (PEB (post-exposure heating)) is performed for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 150 ° C., for example, a tetramethylammonium hydroxide (TMAH) aqueous solution having a concentration of 0.1 to 10% by mass When the alkali development is performed, the exposed portion of the resist film is removed, and the positive resist pattern 2 is formed.
In some cases, a post-baking step may be included after the alkali development.
The wavelength used for the exposure is not particularly limited, and includes KrF excimer laser, ArF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation.

At this time, the selective exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or immersion exposure. In the present invention, it is preferable to perform immersion exposure because a finer reversal pattern can be formed.
In immersion exposure, at the time of exposure, a solvent (having a refractive index larger than the refractive index of air) is formed between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. Exposure is performed in a state filled with the immersion medium.
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure can be performed through a desired mask pattern (immersion exposure).
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film exposed by the immersion exposure is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).

  The positive resist pattern 2 may be a single pattern or a plurality of patterns. In the case of forming a plurality of patterns, a double patterning process by alkali development is performed using a plurality of types of positive resist compositions. Alternatively, after the initial positive resist pattern is formed, a step of freezing the pattern may be provided.

[Step (2)]
Next, a pattern reversal composition 6 containing an organic solvent (S) that does not dissolve the positive resist pattern is applied on the support 1 on which the positive resist pattern 2 is formed, and the pattern reversal film 6 is formed. Form.
The pattern reversal composition preferably contains a base material component (A ″) which is compatible with the organic solvent (S) (hereinafter referred to as “(S) component”). Furthermore, the step (3) Therefore, it is not necessary to deprotect the positive resist pattern because the organic solvent development is carried out in step 1. Therefore, the pattern reversal composition does not contain an acidic compound capable of decomposing the acid-decomposable group (A). preferable.
The pattern reversal composition more preferably does not have an acid-decomposable group from the viewpoint of improving the stability as a composition (solution).
When the pattern reversal composition contains the component (S), dissolution of the positive resist pattern 2 by the organic solvent in the pattern reversal composition when the pattern reversal composition is applied can be suppressed. Deterioration or disappearance of the shape of the mold resist pattern 2, generation of mixing at the interface between the positive resist pattern 2 and the pattern reversal film 6 can be prevented.

Here, “does not dissolve the positive resist pattern” in the component (S) means that a positive resist composition is applied on a support, dried, and dried at 23 ° C. and a film thickness of 0.2 μm. When this is immersed in the organic solvent, even after 60 minutes, the resist film disappears or the film thickness does not change significantly (preferably, the resist film has a thickness of 0.16 μm). Not the following).
The component (S) may be any component that does not dissolve the positive resist pattern and can dissolve the components blended in the pattern reversal composition. Especially, it is preferable that they are an alcohol type organic solvent or an ether type organic solvent which does not have a hydroxyl group. Among these, ether-based organic solvents having no hydroxyl group are preferable from the viewpoint of the coating property on the support and the solubility of the components blended in the pattern reversal composition such as the resin component.
When the organic solvent (S ′) (hereinafter referred to as “(S ′) component”) contained in the positive resist composition is an alcohol organic solvent, the (S) component does not have a hydroxyl group. An ether organic solvent is preferred.
Here, the “alcohol-based organic solvent” is a compound in which at least one of the hydrogen atoms of the aliphatic hydrocarbon is substituted with a hydroxyl group, and is a compound that is liquid at normal temperature and normal pressure. The structure of the main chain constituting the aliphatic hydrocarbon may be a chain structure, may be a cyclic structure, may have a cyclic structure in the chain structure, The chain structure may contain an ether bond.
The “ether-based organic solvent having no hydroxyl group” is a compound that has an ether bond (C—O—C) in its structure, does not have a hydroxyl group, and is liquid at normal temperature and pressure. The ether organic solvent having no hydroxyl group preferably further has no carbonyl group in addition to the hydroxyl group.

As the alcohol organic solvent, monohydric alcohols, dihydric alcohols, derivatives of dihydric alcohols, and the like are preferable.
As the monohydric alcohol, although depending on the number of carbon atoms, a primary or secondary monohydric alcohol is preferable, and a primary monohydric alcohol is most preferable.
Here, the monohydric alcohol means a compound in which one of the hydrogen atoms of a hydrocarbon compound composed only of carbon atoms and hydrogen atoms is substituted with a hydroxyl group, and does not include dihydric or higher polyhydric alcohol derivatives. . The hydrocarbon compound may have a chain structure or a cyclic structure.
The dihydric alcohol means a compound in which two hydrogen atoms of the hydrocarbon compound are substituted with a hydroxyl group, and does not include a trihydric or higher polyhydric alcohol derivative.
Examples of the dihydric alcohol derivative include compounds in which one of the hydroxyl groups of the dihydric alcohol is substituted with a substituent (such as an alkoxy group or an alkoxyalkyloxy group).

The boiling point (under normal pressure) of the alcohol-based organic solvent is preferably 80 to 250 ° C., more preferably 90 to 220 ° C., and 100 to 200 ° C. Most preferable from the viewpoint of stability and baking temperature.
Specific examples of the alcohol-based organic solvent include propylene glycol (PG); 1-butoxy-2-propanol (PGB), n-hexanol, 2-heptanol, 3-heptanol, and 1-heptanol as those having a chain structure. 5-methyl-1-hexanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2- (2-butoxyethoxy) ethanol , N-pentyl alcohol, s-pentyl alcohol, t-pentyl alcohol, isopentyl alcohol, isobutanol (also referred to as isobutyl alcohol or 2-methyl-1-propanol, IBA), isopropyl alcohol, 2-ethylbutanol, neopentyl Alcoa , N- butanol, s- butanol, t-butanol, 1-propanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol (MIBC), and the like.
In addition, as those having a cyclic structure, cyclopentanemethanol, 1-cyclopentylethanol, cyclohexanol, cyclohexanemethanol (CM), cyclohexaneethanol, 1,2,3,6-tetrahydrobenzyl alcohol, exo-norbornol, 2-methyl Examples include cyclohexanol, cycloheptanol, 3,5-dimethylcyclohexanol, and benzyl alcohol.

  Among alcohol-based organic solvents, chain-structured monohydric alcohols or dihydric alcohol derivatives are preferred, such as 1-butoxy-2-propanol (PGB); isobutanol (also known as isobutyl alcohol or 2-methyl-1-propanol). IBA.), 4-methyl-2-pentanol (MIBC) and n-butanol are preferred, and 4-methyl-2-pentanol (MIBC) is most preferred.

Preferred examples of the ether organic solvent having no hydroxyl group include compounds represented by the following general formula (s-1).
R ⁴⁰ —O—R ⁴¹ (s-1)
[Wherein, R ⁴⁰ and R ⁴¹ each independently represent a monovalent hydrocarbon group, and R ⁴⁰ and R ⁴¹ may combine to form a ring. -O- represents an ether bond. ]

In the above formula, examples of the hydrocarbon group for R ⁴⁰ and R ⁴¹ include an alkyl group and an aryl group, and an alkyl group is preferred. Among ^them, it is preferable that any of R ^{40, R 41} is an alkyl ^group, and ^{R 40} and ^{R 41} is more preferably the same alkyl group.
As each of the alkyl groups of R ^40, R ^41, not particularly limited, for example, straight, branched or cyclic alkyl group, and the like. In the alkyl group, part or all of the hydrogen atoms may or may not be substituted with a halogen atom or the like.
The alkyl group preferably has 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms because the coating property of the pattern reversal composition is good. Specific examples include an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a cyclopentyl group, and a hexyl group, and an n-butyl group and an isopentyl group are particularly preferable. .
The halogen atom that may be substituted for the hydrogen atom of the alkyl group is preferably a fluorine atom.
Each aryl group for R ⁴⁰ and R ⁴¹ is not particularly limited, and is, for example, an aryl group having 6 to 12 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups, It may or may not be substituted with a halogen atom or the like.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specifically, a phenyl group, a benzyl group, a naphthyl group, etc. are mentioned, for example.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is more preferable.
As the alkoxy group which may substitute the hydrogen atom of the said aryl group, a C1-C5 alkoxy group is preferable and a methoxy group and an ethoxy group are more preferable.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
In the above formula, R ⁴⁰ and R ⁴¹ may combine to form a ring.
R ⁴⁰ and R ⁴¹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 10 carbon atoms), and the end of R ⁴⁰ is bonded to the end of R ^41. To form a ring. In addition, the carbon atom of the alkylene group may be substituted with an oxygen atom.
Specific examples of the ether organic solvent include 1,8-cineol, tetrahydrofuran, dioxane and the like.

The boiling point (under normal pressure) of the ether-based organic solvent having no hydroxyl group is preferably 30 to 300 ° C, more preferably 100 to 200 ° C, and further preferably 140 to 180 ° C. By being at least the lower limit of the temperature range, the component (S) is less likely to evaporate during spin coating during application of the pattern reversal composition, so that coating unevenness is suppressed and coating properties are improved. On the other hand, by being below the upper limit value, the (S) component is sufficiently removed from the pattern inversion film by pre-baking, and the formability of the pattern inversion film is improved. Further, when the temperature is within this range, the effect of reducing the film thickness of the pattern reversal film and the stability of the composition during storage are further improved. It is also preferable from the viewpoint of baking temperature.
Specific examples of the ether organic solvent having no hydroxyl group include, for example, 1,8-cineol (boiling point 176 ° C.), dibutyl ether (boiling point 142 ° C.), diisopentyl ether (boiling point 171 ° C .; DIAE), dioxane (boiling point). 101 ° C), anisole (boiling point 155 ° C), ethyl benzyl ether (boiling point 189 ° C), diphenyl ether (boiling point 259 ° C), dibenzyl ether (boiling point 297 ° C), phenetole (boiling point 170 ° C), butylphenyl ether, tetrahydrofuran (boiling point) 66 ° C), ethyl propyl ether (boiling point 63 ° C), diisopropyl ether (boiling point 69 ° C), dihexyl ether (boiling point 226 ° C), dipropyl ether (boiling point 91 ° C), and the like.
The ether-based organic solvent having no hydroxyl group is preferably a cyclic or chain-shaped ether-based organic solvent because it has a good effect of reducing film loss of the pattern reversal film, and among these, 1,8-cineole, At least one selected from the group consisting of dibutyl ether and diisopentyl ether (DIAE) is preferred.

The (S) component used in the pattern reversal composition may be a single type or two or more types.
The pattern reversal composition may contain an organic solvent other than the (S) component (hereinafter referred to as the (S ″) component) as long as the effect of using the (S) component is not impaired.
As the component (S ″), those capable of dissolving the components blended in the pattern reversal composition are preferable. Specifically, the same as the component (S ′) mentioned in the description of the positive resist composition described later. Things.
The compounding amount of the component (S ″) is preferably 0 to 20% by mass and more preferably 1 to 15% by mass in the total organic solvent used in the pattern reversal composition.
The amount of the total organic solvent used in the pattern reversal composition is not particularly limited, and is usually an amount that makes the pattern reversal composition a liquid having a concentration that can be applied onto the support. For example, it is used so that the solid content concentration of the pattern reversal composition is in the range of 1 to 30% by mass.

  Specific examples of components (base component (A ″), etc.) other than the component (S) blended in the pattern reversal composition will be described in detail later.

Similar to the positive resist film 2, the pattern reversal film 6 can be formed by a conventionally known method.
Specifically, for example, on the support 1 on which the positive resist pattern 2 is formed, a pattern reversal composition is applied using a conventionally known method such as using a spinner, and a baking process (pre-baking) is performed. By volatilizing the organic solvent, the pattern reversal film 6 filling the gap between the positive resist patterns 2a can be formed.
Then, the resist pattern 2a is removed by organic solvent development in the step (3), and a reverse pattern is formed.

[Step (3)]
Next, the pattern reversal film 6 is developed using an organic solvent developer that dissolves the positive resist pattern 2, thereby removing the positive resist pattern to form a resist pattern (reversal pattern). .
Here, during the development in the step (3), the acid-decomposable group remains in the positive resist pattern 2 (the unexposed portion remains) in the step (1). The solubility of the resist pattern 2 in the organic solvent developer is relatively large, and the solubility of the pattern reversal film 6 in the organic solvent developer is relatively small. Therefore, by this development, the positive resist pattern 2 can be selectively removed and a reverse pattern can be formed.
If the step (3) is performed in an alkali development process instead of an organic solvent development process, an acid-decomposable group that acts as a dissolution-inhibiting group in the alkaline developer remains in the positive resist pattern 2. In order to remove the positive resist pattern 2, it is necessary to further decompose the acid-decomposable group and increase the solubility in an alkali developer. At this time, since the pattern inversion film 6 needs to remain as a final pattern, it is necessary to use the difference in deprotection energy between the positive resist pattern 2 and the pattern inversion film 6. In particular, when the deprotection energy of the positive resist pattern 2 is high, there is a risk that the deprotection reaction of the positive resist pattern 2 may be insufficient. It may be difficult to form. On the other hand, in the present invention, since organic solvent development is performed, such a problem does not occur.

In the present invention, the film thickness of the pattern reversal film 6 (minimum value of the film thickness of the portion filling the gap between the resist patterns 2a) is adjusted to the solubility of the pattern reversal film 6 in the organic solvent developer. What is necessary is just to adjust suitably. When the solubility is slightly high, it is preferable that the film thickness of the pattern reversal film 6 is made larger than the height of the resist pattern 2a. When the solubility is not so high, the film thickness of the pattern reversal film 6 is set to the thickness of the resist pattern 2a. It is preferable that the height is the same as the height, or the thickness of the pattern reversal film 6 covering the upper surface of the resist pattern 2a is thin enough to be easily removed at the time of organic solvent development in the step (3). That is, the pattern reversal film 6 (film formed on the resist pattern 2a) in this portion is thin and is likely to be reduced by organic solvent development. Therefore, it is dissolved and removed together with the resist pattern 2a at the time of development, and a reverse pattern can be formed satisfactorily.
If the pattern reversal film 6 is too thick although the solubility of the pattern reversal film 6 in the organic solvent developer is low (or the development time is short), the resist during the organic solvent development in the step (3) The pattern reversal film 6 on the upper surface of the pattern 2a cannot be removed well.
On the other hand, if the pattern reversal film 6 is too thin (or the development time is long) even though the pattern reversal film 6 has a high solubility in organic solvent development (or a long development time), the organic in the step (3) At the time of solvent development, not only the resist pattern 2a but also the pattern reversal film 6 are all dissolved in the organic solvent developer, and a good reversal pattern may not be formed.

After the pattern reversal film 6 is formed, organic solvent development is performed. As described above, by appropriately adjusting the solubility and film thickness (and development time) of the pattern reversal film 6 in the organic solvent developer, after the organic solvent development, the pattern reversal film 6 on the upper surface of the resist pattern 2a. The existing portion is removed, and the resist pattern 2a is also removed accordingly. On the other hand, the pattern reversal film 6 filled between the resist patterns 2a remains without being removed. As a result, as shown in FIG. 1, a pattern (reversal pattern) obtained by reversing the image of the resist pattern 2a is formed at the position 6c where the resist pattern 2a was present.
For example, when the positive resist pattern is a line pattern, a space pattern having the same dimension (space width) as that of the line pattern is formed as an inverted pattern at the same position as the line pattern. When the positive resist pattern is a dot pattern, a hole pattern having the same size (dot diameter) as that of the dot pattern is formed as an inverted pattern at the same position as the dot pattern.

The organic solvent development treatment is performed using an organic solvent.
The organic solvent is not particularly limited as long as it can dissolve the positive resist pattern 2 and can be appropriately selected from known organic solvents.
Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used.
The ketone solvent is an organic solvent containing C—C (═O) —C in the structure.
The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure.
The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group.
The amide solvent is an organic solvent containing an amide group in the structure.
The ether solvent is an organic solvent containing C—O—C in the structure.
Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification. The hydrocarbon solvent is a hydrocarbon solvent made of hydrocarbon and having no substituent (a group or atom other than a hydrogen atom and a hydrocarbon group).
Specific examples of each solvent include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, Examples include methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, and γ-butyrolactone.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene Recall monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Nethyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyrubin Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate Examples include ethyl acid, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.
As the ester solvent, a solvent represented by general formula (1) described later or a solvent represented by general formula (2) described later is preferably used, and a solvent represented by general formula (1) is used. Is more preferable, alkyl acetate is more preferably used, and butyl acetate is most preferably used.

  Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, monohydric alcohols such as n-octyl alcohol, n-decanol and 3-methoxy-1-butanol; glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, Triethylene glycol monoethyl ether, methoxymethylbutanol, ethylene glycol monoethyl ether, Glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and propylene glycol monophenyl ether, glycol ether solvent containing a hydroxyl group; and the like. Of these, glycol ether solvents are preferred.

Examples of ether solvents include glycol ether solvents containing the above hydroxyl groups; glycol ether solvents that do not contain hydroxyl groups, such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; dioxane, tetrahydrofuran, anisole, Examples include perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, and 1,4-dioxane. Of these, glycol ether solvents such as glycol ether solvents containing hydroxyl groups and glycol ether solvents not containing hydroxyl groups are preferred.
Examples of the amide solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like. Can be mentioned.
Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane, and perfluoroheptane. Aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene, dipropylbenzene; Is mentioned. Among these, aromatic hydrocarbon solvents are preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used, or butyl acetate (BA) and propylene glycol monomethyl ether (PE) may be used in combination. Good. The mixing ratio (BA / PE) is preferably 99/1 to 70/30, more preferably 97/3 to 80/20, and still more preferably 95/5 to 85/15. The solubility of the positive resist pattern 2 and the pattern reversal film 6 can be adjusted by appropriately adjusting the mixing ratio.
Moreover, you may mix and use the organic solvent and water other than the above.

As the organic solvent used in the organic developer, a solvent represented by the following general formula (1) or (2) is preferable.
R ⁰⁰ —C (═O) —O—R ⁰¹ (1)
R ⁰² —C (═O) —O—R ⁰³ —O—R ⁰⁴ (2)
[In the formula (1), R ⁰⁰ and R ⁰¹ are each independently a hydrogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a carboxy group, a hydroxyl group, a cyano group or a halogen atom, and R ⁰⁰ and R ⁰¹ are bonded to each other. To form a ring. In the formula (2), R ⁰² and R ⁰⁴ are each independently a hydrogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a carboxy group, a hydroxyl group, a cyano group, or a halogen atom, and R ⁰² and R ⁰⁴ are bonded to each other. May form a ring, and R ⁰³ is an alkylene group. ]

In formula (1), the alkyl group in R ⁰⁰ and R ⁰¹ may be linear, branched or cyclic, and is preferably linear or branched, and has 1 to 5 carbon atoms. Is preferred. The alkyl group may have a substituent. Examples of the substituent include a hydroxyl group, a carboxy group, and a cyano group.
Examples of the alkyl group in the alkoxy group and alkoxycarbonyl group include the same alkyl groups as those described above.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
R ⁰⁰ and R ⁰¹ are each preferably a hydrogen atom or an alkyl group.
Specific examples of the solvent represented by the formula (1) include, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, lactic acid Butyl, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, Examples include isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, and the like.
Among the above, the solvent represented by the formula (1) is preferably one in which R ⁰⁰ and R ⁰¹ are unsubstituted alkyl groups, more preferably alkyl acetate, and particularly preferably butyl acetate.

In the formula (2), R ⁰² and R ⁰⁴ are the same as R ⁰⁰ and R ⁰¹ , respectively.
The alkylene group for R ⁰³ may be linear, branched or cyclic, and is preferably linear or branched, and preferably has 1 to 5 carbon atoms. The alkylene group may have a substituent. Examples of the substituent include a hydroxyl group, a carboxy group, and a cyano group. When the alkylene group has 2 or more carbon atoms, an oxygen atom (—O—) may be interposed between carbon atoms of the alkylene group.
Specific examples of the solvent represented by the formula (2) include, for example, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoacetate. Propyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methyl-3-meth Cypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, ethyl methoxyacetate, ethyl ethoxyacetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4 -Methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3 -Methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4 Methyl-4-methoxy pentyl acetate, and the like.

Any one of the solvents represented by the formula (1) or (2) may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use with another solvent.
The other solvent is not particularly limited as long as it can be mixed without being separated into the solvent represented by the formula (1) or (2) to be used. For example, the above-described ester solvent, ketone solvent, alcohol It can be suitably selected from among a solvent, an amide solvent, an ether solvent, a hydrocarbon solvent and the like.

As the organic solvent used for organic solvent development, an organic solvent containing no halogen atom is preferably used from the viewpoint of cost reduction of the solvent used for development. The content of the organic solvent not containing halogen atoms in the total weight of the organic developer is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and 100% by mass. Also good.
The boiling point of the organic solvent used in the organic developer is desirably 50 ° C. or higher and lower than 250 ° C.
The ignition point of the organic solvent used in the organic developer is preferably 200 ° C. or higher.

A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.
Examples of commercially available surfactants that can be used include F-top EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Ltd.), MegaFuck F171, F173, F176, F189, and R08. (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

  Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C6F13 group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C6F13 group and (poly (oxyethylene)) acrylate (or Copolymer of methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate), copolymer of acrylate having C8F17 group (or methacrylate) and (poly (oxyalkylene)) acrylate (or methacrylate), C8F17 A copolymer of an acrylate (or methacrylate) having a group, (poly (oxyethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate), etc. It can gel.

As the surfactant, a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 0% with respect to the total amount of the organic developer. 5 mass% is more preferable.

  The development process using an organic solvent can be carried out by a known development method, for example, a method of immersing a support in a developer for a certain period of time (dip method), and a developer on the surface of the support by surface tension. Method of raising and resting for a certain time (paddle method), method of spraying developer on the support surface (spray method), scanning the developer coating nozzle at a constant speed on a support rotating at a constant speed Examples thereof include a method of continuously applying the developer (dynamic dispensing method).

It is preferable to carry out a rinsing treatment using a rinsing liquid containing an organic solvent after the development treatment and before drying. Thereby, a favorable pattern can be formed.
As the organic solvent used for the rinsing liquid, for example, among the organic solvents mentioned as the organic solvent used for the organic solvent development, those which are difficult to dissolve the resist pattern can be appropriately selected and used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A known additive can be blended with the organic solvent as necessary. Examples of the additive include a surfactant. Examples of the surfactant include those described above, and nonionic surfactants are preferable, and fluorine-based surfactants or silicon-based surfactants are more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.
The rinsing treatment (washing treatment) using the rinsing liquid can be carried out by a known rinsing method. For example, the rinsing liquid is continuously applied onto a support rotating at a constant speed (rotary coating method). A method of immersing the support in a rinsing solution for a certain time (dip method), a method of spraying a rinsing solution on the surface of the support (spray method), and the like.

As described above, the solubility of the pattern reversal film 6 in the organic solvent developer during the organic solvent development in the step (3) is smaller than the solubility of the positive resist pattern 2 in the organic solvent developer. .
The solubility in the organic solvent developer in the positive resist pattern 2 and the pattern reversal film 6 is in this relationship, so that the resist pattern 2a is dissolved and removed during development, while the pattern reversal film 6 is A reversal pattern with good resolution is formed without being dissolved and removed in an organic solvent developer.
Such solubility can be controlled by a combination with a base material component (A) or a base material component (A ″) described later.

In the present invention, a space pattern and / or a hole pattern can be obtained as an inverted pattern by forming a line pattern and / or a dot pattern as the positive resist pattern.
Thus, the space pattern and hole pattern formed as a reversal pattern have a resolution, a shape, a lithography margin (for example, a margin with respect to an exposure amount (EL margin), a focal point, and the like, compared with a case where the space pattern and hole pattern are directly formed in one lithography process. It is excellent in pattern forming ability such as a margin with respect to depth (DOF margin), verticality of pattern shape, and the like. That is, when directly forming a space pattern or a hole pattern that requires removal of a very small part or a fine region of the resist film, as described above, it is forced to form a pattern under weak light incident intensity, and the pattern forming ability However, the pattern forming ability when forming the reverse pattern depends on the pattern forming ability when forming the positive resist pattern (isolated line pattern, dot pattern, line and space pattern, etc.). Compared with the case of directly forming a space pattern or a hole pattern, the pattern forming ability is less limited, and a good resist pattern can be formed.

In the pattern forming method of the present invention, the positive resist pattern can be removed by organic solvent development in step (3) by applying the pattern reversal composition in step (2). Therefore, in the pattern forming method of the present invention, compared to the second patterning of the double patterning process, it is not necessary to perform both exposure and post-exposure baking, and a reverse pattern can be formed only by organic solvent development. Therefore, such a pattern forming method has a smaller number of steps than the conventional double patterning process and is a simple method, and the throughput is improved.
Further, in such a pattern forming method, there is no limitation that a specific resist composition such as having the above-mentioned cross-linking ability must be used as a positive resist composition, and there has been no conventionally known conventionally proposed method. The chemically amplified positive resist composition can be used as it is. Moreover, the resin composition etc. which were proposed until now can also be used as a pattern reversal composition as it is.
Furthermore, in the present invention, since organic solvent development is performed, it is not necessary to consider the difference in deprotection energy between the positive resist pattern 2 and the pattern reversal film 6 as described above.

  In the present invention, the operation of the above step (2) may be performed on a resist pattern formed by performing normal patterning twice or more (by double patterning). Thereby, a denser pattern with a narrower pitch or a pattern with a complicated shape can be formed.

Further, in the present invention, after the step (3), the support 1 may be etched using the formed pattern as a mask. A semiconductor device or the like can be manufactured by etching the support 1.
As the etching method, a known method (dry etching, wet etching) can be used. For example, the etching of the organic film (resist pattern, organic antireflection film, etc.) is preferably dry etching. In particular, oxygen plasma etching or etching using CF ₄ gas or CHF ₃ gas is preferable, and oxygen plasma etching is particularly preferable. Etching of the substrate and the inorganic antireflection film is preferably performed using a halogen gas, more preferably using a fluorocarbon-based gas, and particularly preferably using a CF ₄ gas or a CHF ₃ gas.

(Positive resist composition)
In the step (1), the positive resist composition for forming the positive resist pattern is not particularly limited as long as the solubility in an alkaline developer is increased by exposure. Contains a base material component (A) (hereinafter referred to as “component (A)”) having increased solubility, and an acid generator component (B) (hereinafter referred to as “component (B)”) that generates an acid upon exposure. Those that do are preferred.
The component (A) preferably contains an acid-decomposable group.
Furthermore, the positive resist composition preferably has low compatibility with the component (S).
In the positive resist composition, the component (A) is insoluble in an alkali developer before exposure, and when the acid generated from the component (B) acts upon exposure, the entire alkali development of the component (A) is performed. The solubility in the liquid is increased, and the alkali-insoluble is changed to the alkali-soluble. Therefore, when a resist film obtained by using a positive resist composition is selectively exposed in the formation of a resist pattern, the exposed portion turns alkali-soluble, while the unexposed portion remains alkali-insoluble. Therefore, a resist pattern can be formed by alkali development.

<(A) component>
In the positive resist composition, the component (A) may be a resin component (A1) (hereinafter also referred to as “component (A1)”) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound component (A2) (hereinafter sometimes referred to as “component (A2)”) whose solubility in an alkaline developer is increased by the action of an acid, or a mixture thereof. Good.
Among these, it is preferable that (A) component contains (A1) component.

<(A1) component>
The component (A1) suitably used in such a positive resist composition is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. It is preferable to have a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid.
More specifically, the acid-decomposable group is a group in which a polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of a polar group containing a —COOH group or —OH group is substituted with an acid-dissociable group). Is mentioned.
The acid dissociable group has a low solubility with respect to the alkali developer used in step (1) before dissociation and increases the solubility after dissociation, whereas in step (3) The organic solvent developer to be used is a group having high solubility before dissociation and lowering the solubility after dissociation.
In the present invention, the structural unit (a1) is derived from an acrylate ester containing an acid dissociable group, and the structural unit (a11) that generates a —COOH group (carboxy group) after the acid dissociable group is deprotected; It is classified into a structural unit (a0-1) which is derived from an acrylate ester containing an acid dissociable group and generates an alcoholic hydroxyl group after the acid dissociable group is deprotected. The component (A1) more preferably includes the structural unit (a11), and may include both the structural unit (a11) and (a0-1).
In addition to the structural unit (a1), the component (A1) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. And at least one structural unit (a2) selected from the group consisting of a structural unit (a2 ^L ) containing a lactone-containing cyclic group and a structural unit (a2 ^S ) containing a —SO ₂ -containing cyclic group, It is preferable to have.
Further, in the component (A1), in addition to the structural unit (a1) or the structural units (a1) and (a2), a hydrogen atom bonded to the α-position carbon atom may be further substituted with a substituent. It is preferable to have a structural unit (a3) which is a structural unit derived from a good acrylic ester and contains a polar group-containing aliphatic hydrocarbon group.
In addition to the structural unit (a1), the component (A1), in addition to the structural units (a1) and (a2), in addition to the structural units (a1), (a2) and (a3), It is preferable to have a structural unit (a0-2) represented by the following general formula (a0-2).
In addition to the structural unit (a1), the component (A1) has other structural units other than the structural unit (a1), (a2), (a3), or (a0-2). Good

Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” refers to a compound in which the hydrogen atom at the terminal of the carboxy group of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
The substituent in the “acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent” includes a halogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogenated group having 1 to 5 carbon atoms. Examples thereof include an alkyl group and a hydroxyalkyl group.
The α-position carbon atom of the acrylate ester means a carbon atom to which a carbonyl group is bonded unless otherwise specified.
Hereinafter, an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an “α-substituted acrylate ester”. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.
In the α-substituted acrylate ester, examples of the halogen atom that replaces the hydrogen atom bonded to the carbon atom at the α-position include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
The alkyl group that replaces the hydrogen atom bonded to the α-position carbon atom is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, Examples include isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
The halogenated alkyl group that replaces the hydrogen atom bonded to the α-position carbon atom is specifically a part of the hydrogen atom of the above-mentioned “alkyl group that replaces the hydrogen atom bonded to the α-position carbon atom”. Or the group which substituted all with the halogen atom is mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In addition, the hydroxyalkyl group that replaces the hydrogen atom bonded to the α-position carbon atom is a part of or all of the hydrogen atoms of the above-mentioned “alkyl group that replaces the hydrogen atom bonded to the α-position carbon atom” with a hydroxyl group. Examples include substituted groups.
(Α-substituted) Those bonded to the α-position of the acrylate ester are preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom and 1 carbon atom. -5 alkyl groups or fluorinated alkyl groups having 1 to 5 carbon atoms are more preferable, and a hydrogen atom or a methyl group is particularly preferable from the viewpoint of industrial availability.

・ Structural unit (a11)
The structural unit (a11) is derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom containing the acid dissociable group may be substituted with a substituent, and the acid dissociable group is deprotected. A structural unit that produces a —COOH group.
The acid dissociable group in the structural unit (a11) has an alkali dissolution inhibiting property that makes the entire component (A1) hardly soluble in an alkali developer before dissociation, and dissociates with an acid to dissociate the entire component (A1). Can be used, which can be used as an acid-dissociable group of a base resin for a chemically amplified resist.
In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable group such as an alkoxyalkyl group is widely known. The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable group include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.

Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, compound, or the like that does not have aromaticity.
“Aliphatic branched” means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples thereof include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a11) may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include a monocycloalkane, a bicycloalkane, and a tricyclo which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group. Examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as an alkane or tetracycloalkane. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

  Examples of the acid-dissociable group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group, specifically, 2-methyl-2-adamantyl. Group, 2-ethyl-2-adamantyl group and the like. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) A group having an aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecyl group, or a tetracyclododecyl group and a branched alkylene group having a tertiary carbon atom bonded thereto. Can be mentioned.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し；Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁵ and R ¹⁶ are alkyl groups (both linear and branched); Well, preferably 1 to 5 carbon atoms). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms in R is hydrogen bonded to the α-position carbon atom. This is the same as the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms for substituting the atoms.

The “acetal acid dissociable group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable group and the oxygen atom to which the acetal acid dissociable group is bonded.
Examples of the acetal type acid dissociable group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎ’は０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n ′ represents an integer of 0 to 3 and Y represents an alkyl having 1 to 5 carbon atoms. Represents a group or an aliphatic cyclic group. ]

In the above formula, n ′ is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms of R ¹ ′ and R ² ′ include those similar to the alkyl group having 1 to 5 carbon atoms of R, preferably a methyl group or an ethyl group, and most preferably a methyl group. preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ’、Ｙは上記と同様である。］

[Wherein R ¹ ′, n ′ and Y are the same as described above. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Y include the same as the alkyl group having 1 to 5 carbon atoms of R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ And may be combined.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a11), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し；Ｘ^１は酸解離性基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; X ¹ represents an acid dissociable group. ]

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し；Ｘ^２は酸解離性基を示し；Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; X ² represents an acid dissociable group; Y ² represents a divalent linking group. Show. ]

In the general formula (a1-0-1), the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms of R may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group having ˜5 or the halogenated alkyl group having 1 to 5 carbon atoms.
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. Type acid dissociable groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Examples of the divalent linking group for Y ² include an alkylene group, a divalent aliphatic cyclic group, and a divalent linking group containing a hetero atom.
As the aliphatic cyclic group, those similar to the explanation of the “aliphatic cyclic group” can be used except that a group in which two or more hydrogen atoms are removed is used.
When Y ² is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .
When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—. , —S (═O) ₂ —, —S (═O) ₂ —O—, “—AO (oxygen atom) —B— (wherein A and B each independently have a substituent) A divalent hydrocarbon group that may be present.) ”,“ —A—O—C (═O) —B— ”and the like.

When Y ² is —NH—, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred that
When Y ² is “A—O—B” or “—A—O—C (═O) —B—”, A and B may each independently have a substituent 2 Valent hydrocarbon group.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.

  The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.

The aliphatic hydrocarbon group for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - Alkylethylene groups such as CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group bonded to the terminal of the aromatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specifically, the polycycloalkane includes adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

  A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

  More specifically, examples of the structural unit (a11) include structural units represented by general formulas (a1-1) to (a1-4) shown below.

［式中、Ｘ’は第３級アルキルエステル型酸解離性基を表し、Ｙは炭素数１〜５のアルキル基、または脂肪族環式基を表し；ｎ’は０〜３の整数を表し；Ｙ^２は２価の連結基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester-type acid dissociable group, Y represents an alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group; n ′ represents an integer of 0 to 3] Y ² represents a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; ]

In the formula, X 'include the same tertiary alkyl ester-type acid dissociable groups described above for X ^{1.
R 1 ', R 2',} n ', as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable group" described above ^{(p1)', R 2 '} , n', Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in general formula (a1-0-2)

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

As the structural unit (a11), one type may be used alone, or two or more types may be used in combination.
Among these, structural units represented by general formula (a1-1), (a1-2) or (a1-3) are preferable, and specifically, the formulas (a1-1-1) to (a1-1-1-) are preferable. 7), formulas (a1-1-36) to (a1-1-42), formulas (a1-1-47) to (a1-1-50), formulas (a1-1-51) to (a1-1) -54); Formula (a1-2-3), (a1-2-4), (a1-2-9), (a1-2-10), (a1-2-13), (a1-2) 14), (a1-2-17), (a1-2-18), (a1-2-20), (a1-2-21) to (a1-231); formula (a1-3-49) ) To (a1-3-56) and at least one selected from the group consisting of structural units represented by formulas (a1-3-57) to (a1-3-58) are more preferable.
Further, the structural unit (a11) is particularly represented by the formula (a1-1-1) to the formula (a1-1-5) and the formula (a1-1-47) to the formula (a1-1-50). Represented by the following general formula (a1-1-01) including the structural units represented by formula (a1-1-28), formula (a1-1-31) to formula (a1-1-34), ( a1-1-36) to (a1-1-42) and formulas (a1-1-51) to (a1-1-54) include the structural units represented by the following general formula (a1-1-02) Those represented by formulas (a1-2-3), (a1-2-4), (a1-2-9), (a1-2-10), (a1-2-13), (a1 -2-14), (a1-2-17), (a1-2-18) and (a1-2-20) are represented by the following general formula (a1-2-01) including the structural units represented by Is A compound represented by the following general formula (a1-2-02) including structural units represented by (a1-2-21) to (a1-231); a formula (a1-3-57) Represented by the following general formula (a1-3-01) including structural units represented by (a1-3-58) and formulas (a1-3-59) to (a1-3-60) Represented by the following general formula (a1-3-02) including the structural units represented by the following general formulas including the structural units of the formulas (a1-3-49) to (a1-3-52) What is represented by (a1-3-03), and is represented by the following general formula (a1-3-04) including the structural units of formulas (a1-3-53) to (a1-3-56) Is also preferable.

［式（ａ１−１−０１）中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し、Ｒ^１１は炭素数１〜５のアルキル基を示す。式（ａ１−１−０２）中、Ｒは前記と同じであり、Ｒ^１２は炭素数１〜５のアルキル基を示し、ｊは１〜６の整数を表す。］

[In formula (a1-1-01), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and R ¹¹ represents an alkyl group having 1 to 5 carbon atoms. Show. In formula (a1-1-02), R is the same as defined above, R ¹² represents an alkyl group having 1 to 5 carbon atoms, and j represents an integer of 1 to 6. ]

In general formula (a1-1-01), R is the same as defined above.
The alkyl group having 1 to 5 carbon atoms of R ¹¹ is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group.

In general formula (a1-1-02), R is the same as defined above.
The alkyl group having 1 to 5 carbon atoms of R ¹² is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group. j is preferably 1 or 2, and most preferably 2.

［式（ａ１−２−０１）中、Ｒは前記と同じであり、Ｒ^１’，Ｒ^２’およびｎはそれぞれ前記と同じである。式（ａ１−２−０２）中、Ｒ、Ｒ^１’，Ｒ^２’およびｎは式（ａ１−２−０１）におけるＲ、Ｒ^１’，Ｒ^２’およびｎとそれぞれ同じであり、ｊは１〜６の整数を表す。］

[In formula (a1-2-01), R is as defined above, and R ¹ ′, R ² ′ and n are as defined above. Wherein ^{(a1-2-02), R, R 1} ', R 2' and n are ^{R, R 1 ', R 2} ' respectively and n the same in the formula (a1-2-01), j is The integer of 1-6 is represented. ]

In general formula (a1-2-01), R is the same as described above.
R ¹ ′ and R ² ′ are each independently preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group, and at least one of R ¹ ′ and R ² ′ is a hydrogen atom. Is particularly preferred.
n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
In general formula (a1-2-02), R, R ¹ ′, R ² ′ and n are the same as R, R ¹ ′, R ² ′ and n in general formula (a1-2-01), respectively. is there.
j is preferably 1 or 2, and most preferably 2.

［式（ａ１−３−０１）中、Ｒは前記と同じであり、Ｒ^１４は炭素数１〜５のアルキル基であり、ｑは１〜１０の整数であり、ｒは１〜１０の整数である。式（ａ１−３−０２）中、Ｒ、Ｒ^１４、ｑ、ｒは式（ａ１−３−０１）におけるＲ、Ｒ^１４、ｑ、ｒとそれぞれ同じであり、ｔは１〜６の整数である。式（ａ１−３−０３）中、Ｒ、Ｒ^１４、ｑ、ｒは式（ａ１−３−０１）におけるＲ、Ｒ^１４、ｑ、ｒとそれぞれ同じである。式（ａ１−３−０４）中、Ｒ、Ｒ^１４、ｑ、ｒ、ｔは式（ａ１−３−０２）におけるＲ、Ｒ^１４、ｑ、ｒ、ｔとそれぞれ同じである。］

[In formula (a1-3-01), R is as defined above, R ¹⁴ is an alkyl group having 1 to 5 carbon atoms, q is an integer of 1 to 10, and r is an integer of 1 to 10. It is. Wherein ^{(a1-3-02), R, R 14} , q, r is ^{R, R 14, q,} respectively r the same in the formula (a1-3-01), t is an integer from 1 to 6 is there. Wherein ^{(a1-3-03), R, R 14} , q, r are ^{R, R 14, q,} respectively r the same in the formula (a1-3-01). Wherein ^{(a1-3-04), R, R 14} , q, r, t is the ^{R, R 14, q, r} , respectively t the same in formula (a1-3-02). ]

In general formula (a1-3-01) and general formula (a1-3-03), R is the same as described above.
The alkyl group having 1 to 5 carbon atoms of R ¹⁴ is the same as the alkyl group having 1 to 5 carbon atoms in R, preferably a methyl group or an ethyl group, and more preferably a methyl group.
q is an integer of 1 to 10, an integer of 1 to 5 is preferable, and 1 or 2 is particularly preferable.
r is an integer of 1 to 10, an integer of 1 to 5 is preferable, and 1 or 2 is particularly preferable.

Formula (a1-3-02), in the general formula ^{(a1-3-04), R, R 14} , q, for r is, ^R in the general formula ^{(a1-3-01), R 14, q} , r Are the same.
t is an integer of 1 to 6, preferably 1 to 4, and more preferably 1 or 2.

  The proportion of the structural unit (a11) in the component (A1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the positive resist composition is obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

-Structural unit (a2)
The structural unit (a2) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a —SO ₂ — containing cyclic group. A structural unit derived from an acrylate ester (hereinafter referred to as a structural unit (a2 ^S )) and a structural unit derived from an acrylate ester containing a lactone-containing cyclic group (hereinafter referred to as a structural unit (a2 ^L )). At least one structural unit selected from the group consisting of:
The structural unit (a2) contains a —SO ₂ — containing cyclic group or a lactone cyclic group, whereby a resist film formed using the positive resist composition containing the component (A1) is applied to the substrate. It contributes to the improvement of lithography properties by increasing the adhesion and affinity with a developer containing water.

-Structural unit (a2 ^S ):
The structural unit (a2 ^S ) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a —SO ₂ — containing cyclic group. It is a structural unit derived from an acrylate ester.
Here, -SO ₂ - and containing cyclic group, -SO ₂ - within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO ₂ - in the sulfur atom (S) Are cyclic groups that form part of the ring skeleton of the cyclic group. A ring containing —SO ₂ — in the ring skeleton is counted as one ring, and if it is only the ring, it is a monocyclic group, and if it has another ring structure, it is polycyclic regardless of the structure It is called a group. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed.
The —SO ₂ — containing cyclic group preferably has 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. . However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include a group in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in —COOR ″ and —OC (═O) R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. Group.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、Ａ’は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｚは０〜２の整数であり、Ｒ^２７はアルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基である。］

[In the formula, A ′ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, z is an integer of 0 to 2, and R ²⁷ is an alkyl group. , An alkoxy group, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, and R ″ is a hydrogen atom or an alkyl group.]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ²⁷ may be the same or different.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ²⁷ , the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. In the formula, “Ac” represents an acetyl group.

As the —SO ₂ — containing cyclic group, among the above, groups represented by the general formulas (3-1), (3-3), and (3-4) are preferable, and the chemical formula (3-1-1- It is more preferable to use at least one selected from the group consisting of groups represented by 1), (3-1-18), (3-3-1) and (3-4-1) The group represented by the chemical formula (3-1-1) is most preferable.

More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-0) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^２８は−ＳＯ_２−含有環式基であり、Ｒ^２９は単結合または２価の連結基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²⁸ represents a —SO ₂ — containing cyclic group, and R ²⁹ represents a single bond. Or it is a bivalent coupling group. ]

In formula (a2-0), R is the same as defined above.
R ²⁸ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
The divalent linking group for R ²⁹ is not particularly limited. For example, as the divalent linking group for Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a11). The thing similar to what was mentioned is mentioned. Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
The alkylene group is preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and branched alkylene group mentioned as the aliphatic hydrocarbon group for Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ³⁰ —C (═O) —O— [wherein R ³⁰ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-0-1).

［式中、ＲおよびＲ^２８はそれぞれ前記と同様であり、Ｒ^３０は２価の連結基である。］

[Wherein, R and R ²⁸ are the same as defined above, and R ³⁰ is a divalent linking group. ]

R ³⁰ is not particularly limited, and for example, the same as the divalent linking group for Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a1). Things.
The divalent linking group for R ³⁰ is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
Examples of the linear or branched alkylene group, divalent alicyclic hydrocarbon group, and divalent linking group containing a hetero atom include the linear or branched groups mentioned above as preferred for Y ^2. Examples thereof include the same chain alkylene groups, divalent alicyclic hydrocarbon groups, and divalent linking groups containing a hetero atom.
Among these, a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above formulas -A-O-B-,-[A-C (= O) -O] _m A group represented by —B— or —A—O—C (═O) —B— is more preferable.
Among them, preferred is a group represented by the formula -A-O-C (= O ) -B-, - represented by _{- (CH 2) c -C (} = O) -O- (CH 2) d The group is particularly preferred. c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a0-1-11) or (a0-1-12) shown below is particularly preferable, and represented by formula (a0-1-12). A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^２７、ｚおよびＲ^３０はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ²⁷ , z and R ³⁰ are the same as defined above. ]

In formula (a0-1-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
R ³⁰ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R ^30, the linear or branched alkylene group mentioned above and a divalent linking group containing an oxygen atom are mentioned. Examples are the same as the linking group.
As the structural unit represented by the formula (a0-1-12), a structural unit represented by the following general formula (a0-1-12a) or (a0-1-12b) is particularly preferable.

［式中、ＲおよびＡ’はそれぞれ前記と同じであり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and A ′ are the same as defined above, and c to e are each independently an integer of 1 to 3.] ]

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and an acrylate ester containing a lactone-containing cyclic group Is a structural unit derived from
Here, the lactone-containing cyclic group refers to a cyclic group containing a ring (lactone ring) containing —O—C (O) — in the ring skeleton. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
Examples of the structural unit (a2 ^L ) include those obtained by substituting R ²⁸ in the general formula (a2-0) with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-5) is mentioned.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；Ｒ’はそれぞれ独立に水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０〜２の整数であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり；ｍは０または１である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, carbon An alkoxy group of 1 to 5 or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is an integer of 0 to 2; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
The alkyl group in R ″ may be linear, branched or cyclic.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.
R ²⁹ is the same as ^{R 29} in the aforementioned general formula (a2-0).
In formula (a2-1), s ″ is preferably 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a2 ^L ), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formula (a2-1) to More preferably, at least one selected from the group consisting of structural units represented by (a2-3) is selected from the group consisting of structural units represented by the general formula (a2-1) or (a2-2) Particularly preferred is at least one of the above.
Among them, the formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-2-12), (a2-2-2-) 14), (a2-3-1), at least one selected from the group consisting of structural units represented by (a2-3-5) is preferred.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, or only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.

  In the component (A1), the proportion of the structural unit (a2) is preferably 1 to 80 mol%, and preferably 10 to 70 mol%, based on the total of all structural units constituting the component (A1). Is more preferable, it is more preferable that it is 10-65 mol%, and 10-60 mol% is especially preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

・ Structural unit (a3)
The structural unit (a3) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and an acrylic group containing a polar group-containing aliphatic hydrocarbon group A structural unit derived from an acid ester. However, it is distinguished from structural units (a0-1) and (a0-2) described later for the sake of convenience, and the structural unit (a0-1) or (a0-2) is not included in (a3).
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2), (a3-3) ) Is preferable.

［式中、Ｒは前記と同じであり、ｋは１〜３の整数であり；ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数であり；ｘは１〜２の整数であり、ｙは０〜２の整数であり、ｚは１〜３の整数であり、ｙ＋ｚは２以上の整数である。］

[Wherein, R is as defined above, k is an integer of 1 to 3; t ′ is an integer of 1 to 3, l is an integer of 1 to 5, and s is an integer of 1 to 3] X is an integer of 1 to 2, y is an integer of 0 to 2, z is an integer of 1 to 3, and y + z is an integer of 2 or more. ]

In formula (a3-1), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

In formula (a3-2), t ′ is preferably 1. l is preferably 1.
s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

In the formula (a3-3), x is an integer of 1 to 2, and preferably 1.
y is an integer of 0 to 2, preferably 1.
z is an integer of 1 to 3, preferably 2.
y + z is an integer greater than or equal to 2, Preferably it is 2-4, Most preferably, it is 3.
Of these, 3-methacryloyloxy-4-hydroxytetrahydrofuran and 3-acryloyloxy-4-hydroxytetrahydrofuran are particularly preferable.
By having the structural unit represented by the formula (a3-3), in addition to increasing the affinity with the developer, the effect of improving the adhesion of the resist film to the substrate can also be obtained.

In the component (A1), as the structural unit (a3), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a3) in the component (A1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on all the structural units constituting the component (A1). 25 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a0-1)
The structural unit (a0-1) is derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom containing the acid dissociable group may be substituted with a substituent, and the acid dissociable group is deprotected. Is a unit that generates an alcoholic hydroxyl group, and is preferably a structural unit represented by the following general formula (a0-1).

[In the formula (a0-1), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms; Y ¹ represents an aliphatic cyclic group; Yes; Z is a tertiary alkyl group-containing group or alkoxyalkyl group; a is an integer of 1 to 3, b is an integer of 0 to 2 and a + b = 1 to 3; c, d and e are each independently an integer of 0 to 3. ]

  In general formula (a0-1), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms. For the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms of R, the alkyl group having 1 to 5 carbon atoms or 1 to 1 carbon atoms which may be bonded to the α-position of the acrylate ester. Same as pentahalogenated alkyl group. Among them, R is preferably a hydrogen atom or a methyl group.

In general formula (a0-1), Y ¹ represents an aliphatic cyclic group.
Here, in the present specification and claims, the “aliphatic cyclic group” indicates a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a0-1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The structure of the basic ring (aliphatic ring) excluding the substituent of “aliphatic cyclic group” is not limited to being a ring composed of carbon and hydrogen (hydrocarbon ring), but is a hydrocarbon ring. It is preferable. The “hydrocarbon ring” may be either saturated or unsaturated, but is usually preferably saturated.
Further, a part of the carbon atoms constituting the aliphatic cyclic group may be substituted with a substituent containing a hetero atom, and a part or all of the hydrogen atoms constituting the aliphatic cyclic group are hetero atoms. It may be substituted with a substituent containing
The “heteroatom” in Y ¹ is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may consist of only the hetero atom, or may be a group containing the hetero atom and a group or atom other than the hetero atom. Specifically, for example, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, -NH- (H is an alkyl group, may be substituted with a substituent such as an acyl _{group), - S -, - S} (= O) 2 -, - S (= O) 2 -O- and the like can be mentioned It is done.
The aliphatic cyclic group may be either a polycyclic group or a monocyclic group. Examples of the aliphatic cyclic group include a monocycloalkane, a bicycloalkane, and a tricyclo which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group. Examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as an alkane or tetracycloalkane. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are listed. . The aliphatic cyclic group in the structural unit (a0-1) is preferably a polycyclic group, and among them, a group obtained by removing two or more hydrogen atoms from adamantane is preferable.

In the general formula (a0-1), Z represents a tertiary alkyl group-containing group or an alkoxyalkyl group.
Here, in the present specification and claims, the “tertiary alkyl group” refers to an alkyl group having a tertiary carbon atom. As described above, the “alkyl group” represents a monovalent saturated hydrocarbon group, and includes a chain (straight chain or branched chain) alkyl group and an alkyl group having a cyclic structure.
The “tertiary alkyl group-containing group” refers to a group containing a tertiary alkyl group in its structure. The tertiary alkyl group-containing group may be composed only of a tertiary alkyl group, or may be composed of a tertiary alkyl group and another atom or group other than the tertiary alkyl group. .
Examples of the “atom or group other than the tertiary alkyl group” that constitutes the tertiary alkyl group-containing group together with the tertiary alkyl group include a carbonyloxy group, a carbonyl group, an alkylene group, an oxygen atom, and the like. .

Examples of the tertiary alkyl group-containing group for Z include a tertiary alkyl group-containing group having no cyclic structure, a tertiary alkyl group-containing group having a cyclic structure, and the like.
A tertiary alkyl group-containing group having no cyclic structure is a group containing a branched tertiary alkyl group as the tertiary alkyl group and having no cyclic structure in the structure.
Examples of the branched tertiary alkyl group include groups represented by the following general formula (I).

In formula (I), R ^{21 to} R ²³ are each independently a linear or branched alkyl group. 1-5 are preferable and, as for carbon number of this alkyl group, 1-3 are more preferable.
Moreover, it is preferable that the total carbon number of group represented by general formula (I) is 4-7, it is more preferable that it is 4-6, and it is most preferable that it is 4-5.
Preferred examples of the group represented by the general formula (I) include a tert-butyl group and a tert-pentyl group, and a tert-butyl group is more preferable.

Examples of the tertiary alkyl group-containing group that does not have a cyclic structure include the above-described branched tertiary alkyl group; the above-described branched tertiary alkyl group is a linear or branched alkylene group A tertiary alkyl group-containing chain alkyl group bonded to the above; a tertiary alkyloxycarbonyl group having the branched tertiary alkyl group described above as the tertiary alkyl group; And tertiary alkyloxycarbonylalkyl groups having a branched tertiary alkyl group.
The alkylene group in the tertiary alkyl group-containing chain alkyl group is preferably an alkylene group having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and still more preferably an alkylene group having 1 to 2 carbon atoms. .
Examples of the chain-like tertiary alkyloxycarbonyl group include a group represented by the following general formula (II). ^R 21 ^{to R 23} in the formula (II) is the same as ^R 21 ^{to R 23} in general formula (I). The chain-like tertiary alkyloxycarbonyl group is preferably a tert-butyloxycarbonyl group (t-boc) or a tert-pentyloxycarbonyl group.

Examples of the chain-like tertiary alkyloxycarbonylalkyl group include a group represented by the following general formula (III). ^R 21 ^{to R 23} in the formula (III) are the same as ^R 21 ^{to R 23} in general formula (I). f is an integer of 1 to 3, and 1 or 2 is preferable. As the chain-like tertiary alkyloxycarbonylalkyl group, a tert-butyloxycarbonylmethyl group and a tert-butyloxycarbonylethyl group are preferable.
Of these, the tertiary alkyl group-containing group having no cyclic structure is preferably a tertiary alkyloxycarbonyl group or a tertiary alkyloxycarbonylalkyl group, more preferably a tertiary alkyloxycarbonyl group. A tert-butyloxycarbonyl group (t-boc) is most preferred.

The tertiary alkyl group-containing group having a cyclic structure is a group having a tertiary carbon atom and a cyclic structure in the structure.
In the tertiary alkyl group-containing group having a cyclic structure, the cyclic structure preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and more preferably 6 to 10 carbon atoms constituting the ring. Most preferred. Examples of the cyclic structure include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Preferable examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Examples of the tertiary alkyl group-containing group having a cyclic structure include a group having the following group (1) or (2) as a tertiary alkyl group.
(1) A group in which a linear or branched alkyl group is bonded to a carbon atom constituting a ring of a cyclic alkyl group (cycloalkyl group), and the carbon atom is a tertiary carbon atom.
(2) A group in which an alkylene group having a tertiary carbon atom (branched alkylene group) is bonded to the carbon atom constituting the ring of the cycloalkyl group.

  The linear or branched alkyl group in the group (1) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. . Examples of the group (1) include a 2-methyl-2-adamantyl group, a 2-ethyl-2-adamantyl group, a 1-methyl-1-cycloalkyl group, and a 1-ethyl-1-cycloalkyl group.

In the above (2), the cycloalkyl group to which the branched alkylene group is bonded may have a substituent. Examples of the substituent include a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.
Examples of the group (2) include groups represented by the following chemical formula (IV).

In the formula (IV), R ²⁴ is a cycloalkyl group which may or may not have a substituent. Examples of the substituent that the cycloalkyl group may have include a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).
R ²⁵ and R ²⁶ are each independently a linear or branched alkyl group, and the alkyl group is the same as the alkyl group of R ^{21 to} R ²³ in the formula (I). Can be mentioned.

  Examples of the alkoxyalkyl group for Z include groups represented by the following general formula (V).

In the formula, R ⁴¹ is a linear, branched or cyclic alkyl group.
When R ⁴¹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ⁴¹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. For example, one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group And the like except for. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. . Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
^R42 is a linear or branched alkylene group. The alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 1 to 2 carbon atoms.
As the alkoxyalkyl group for Z, a group represented by the following general formula (VI) is particularly preferable.

In the formula (VI), R ⁴¹ is the same as described above, and R ⁴³ and R ⁴⁴ are each independently a linear or branched alkyl group or a hydrogen atom.
In R ⁴³ and R ⁴⁴ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, one of R ⁴³ and R ⁴⁴ is preferably a hydrogen atom and the other is a methyl group.

  Among these, as Z, a tertiary alkyl group-containing group is preferable, a group represented by the general formula (II) is more preferable, and a tert-butyloxycarbonyl group (t-boc) is most preferable.

In the general formula (a0-1), a is an integer of 1 to 3, b is an integer of 0 to 2, and a + b = 1 to 3.
a is preferably 1 or 2. By setting a to 1 or 2, it is excellent in suppressing the resist pattern collapse and improving the pattern shape. Furthermore, it is thought that it is excellent also in the effect which makes a proximity effect small. The proximity effect refers to the effect that the size and shape of the resist pattern to be formed are affected by the pattern formed in the vicinity of the resist pattern. In the case of forming each, it is preferable because the dimensional difference between patterns at each pitch can be reduced. Moreover, when a is 2, it is preferable at the point which is excellent in the solubility with respect to a negative developing solution (organic type developing solution).
b is preferably 0.
a + b is preferably 1 or 2.
c is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
d is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
e is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

  As the structural unit (a0-1), a structural unit represented by general formula (a0-1-1), (a0-1-2) or (a0-1-3) shown below is particularly desirable.

［式中、Ｒ，Ｚ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。］

[Wherein R, Z, b, c, d and e are the same as defined above. ]

［式中、Ｒ，Ｚ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。複数のｅおよびＺは互いに異なっていてもよい。］

[Wherein R, Z, b, c, d and e are the same as defined above. Several e and Z may mutually differ. ]

［式中、Ｒ，Ｚ，ａ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。ｃ”は１〜３の整数である。］
式（ａ０−１−３）中、ｃ”は１〜３の整数であり、１または２であることが好ましく、１であることがより好ましい。
前記式（ａ０−１−３）におけるｃが０の場合、アクリル酸エステルのカルボニルオキシ基（−Ｃ（＝Ｏ）−Ｏ−）の末端の酸素原子は、環式基中の酸素原子に結合する炭素原子には結合していないことが好ましい。すなわち、ｃが０の場合、当該末端の酸素原子と当該環式基中の酸素原子との間には炭素原子が２つ以上存在する（この炭素原子の数が１である（すなわちアセタール結合となる）場合を除く）ことが好ましい。

[Wherein R, Z, a, b, c, d and e are the same as defined above. c ″ is an integer of 1 to 3.]
In formula (a0-1-3), c ″ is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.
When c in the formula (a0-1-3) is 0, the oxygen atom at the terminal of the carbonyloxy group (—C (═O) —O—) of the acrylate ester is bonded to the oxygen atom in the cyclic group. It is preferable that it is not bonded to the carbon atom. That is, when c is 0, there are two or more carbon atoms between the terminal oxygen atom and the oxygen atom in the cyclic group (the number of carbon atoms is 1 (that is, acetal bond and It is preferable that the above is excluded).

  The monomer for deriving the structural unit (a0-1) is, for example, a compound represented by the following general formula (a0-1-0 ′) (an acryl containing an aliphatic cyclic group having 1 to 3 alcoholic hydroxyl groups) The acid ester) can be synthesized by protecting some or all of the hydroxyl groups with a tertiary alkyl group-containing group or an alkoxyalkyl group using a known method.

［式中、Ｒ，Ｙ^１，ａ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。］

[Wherein, R, Y ¹ , a, b, c, d, and e are the same as defined above. ]

As the structural unit (a0-1), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a0-1) in the component (A1) is preferably 1 to 50 mol%, and preferably 5 to 45 mol%, based on the total of all structural units constituting the component (A1). It is more preferable. By setting it to the lower limit or higher, solubility in an organic solvent such as an alcoholic organic solvent is improved, and when it is lower than the upper limit, the balance with other structural units is good.

・ Structural unit (a0-2)
The structural unit (a0-2) is a structural unit represented by the following general formula (a0-2).

［式（ａ０−２）中、Ｒは水素原子、炭素原子数１〜５の低級アルキル基、又は炭素原子数１〜５のハロゲン化低級アルキル基であり；Ｙ^３はアルキレン基又は脂肪族環式基であり；ｇ、ｈはそれぞれ独立して０〜３の整数であり；ｉは１〜３の整数である。］

[In the formula (a0-2), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms; Y ³ represents an alkylene group or an aliphatic ring. G and h are each independently an integer of 0 to 3; i is an integer of 1 to 3; ]

In general formula (a0-2), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms. R may be the same as R in the formula (a0-1).
Y ³ is an alkylene group or an aliphatic cyclic group.
Examples of the alkylene group for Y ³ include alkylene groups having 1 to 10 carbon atoms.
Examples of the aliphatic cyclic group for Y ³ include the same groups as those described above for Y ¹ in the formula (a0-1).
Y ³ preferably has the same basic ring (aliphatic ring) structure as Y ¹ .
g is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
h is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
i is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

［式中、Ｒ，ｇ，ｈ，ｉはそれぞれ前記と同じである。］

[Wherein R, g, h and i are the same as defined above. ]

As the structural unit (a0-2), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a0-2) in the component (A1) is preferably 1 to 40 mol%, and preferably 1 to 35 mol% with respect to the total of all the structural units constituting the component (A1). More preferably, it is more preferable that it is 5-30 mol%, and 5-25 mol% is the most preferable. By setting the lower limit value or more, the cross-sectional shape is highly rectangular, and a resist pattern having a good shape can be formed. If the upper limit value or less, the balance with other structural units is good.

・ Structural unit (a4)
The component (A1) may contain other structural units (a4) other than the structural units (a1) to (a3) and (a0-2) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those similar to those exemplified in the case of the structural unit (a11), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

  When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). 10 to 20 mol% is more preferable.

In the positive resist composition, the component (A1) includes a copolymer having the structural units (a11) and (a2); a copolymer having the structural units (a11) and (a0-1); ), A copolymer having (a2) and (a0-1); a copolymer having structural units (a11) and (a0-2); a structural unit (a11), (a2) and (a0-2). Copolymer having structural units (a11), (a0-1) and (a0-2); structural units (a11), (a2), (a0-1) and (a0-2) The copolymer which has is mentioned. Examples of such copolymers include copolymers comprising the structural units (a11), (a2), (a0-1) and (a0-2); the structural units (a11), (a2), (a0-1). And a copolymer consisting of structural units (a11), (a0-1) and (a3).
In the positive resist composition, the component (A1) preferably contains the following combination of structural units.

［式中、Ｒ、Ｒ^１１、Ｒ^２９、ｓ”はそれぞれ前記と同じであり、式中に複数あるＲはそれぞれ同じであっても異なっていてもよい。ｊ１”は、１〜３の整数である。］

[Wherein R, R ¹¹ , R ²⁹ , and s ″ are the same as defined above, and a plurality of R in the formula may be the same or different. J1 ″ is an integer of 1 to 3. It is. ]

［式（Ａ１−１）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-1), R is the same as above, and a plurality of R may be the same or different from each other. R ¹¹ is the same as ^{R 11} in formula (a1-1-01). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−２）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。ｎは上記式（ｐ１）におけるｎと同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-2), R is the same as above, and a plurality of R may be the same or different from each other. n is the same as n in the above formula (p1). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−３）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-3), R is the same as above, and a plurality of R may be the same as or different from each other. R ¹¹ is the same as ^{R 11} in formula (a1-1-01). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−４）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-4), R is the same as above, and a plurality of R may be the same or different from each other. R ¹¹ is the same as ^{R 11} in formula (a1-1-01). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−５）中、Ｒは前記と同じであり、複数のＲはそれぞれ同じであってもよく異なっていてもよい。Ｒ^１４、ｑおよびｒはそれぞれ前記と同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-5), R is the same as defined above, and the plurality of R may be the same or different. R ¹⁴ , q and r are the same as defined above. R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−６）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-6), R is the same as above, and a plurality of R may be the same as or different from each other. R ¹¹ is the same as ^{R 11} in formula (a1-1-01). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−７）中、Ｒは上記と同じであり、Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じであり、Ｒ^１２およびｊは式（ａ１−１−０２）におけるＲ^１２およびｊとそれぞれ同じであり、Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。複数のＲ、Ｒ^２１〜Ｒ^２３、ｅは相互に同じであっても異なっていてもよい。］

Wherein (A1-7), R is as defined ^{above, R 11} is the same as ^{R 11} in formula ^{(a1-1-01), R 12} and j in formula (a1-1-02) are each and R ¹² and j ^same, R 21 ^{to R 23} are the same respectively as ^R 21 ^{to R 23} in formula (II), e is the same as e in formula (a0-1). A plurality of R, R ^{21 to} R ²³ and e may be the same as or different from each other. ]

［式（Ａ１−８）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じである。Ｒ^１２およびｊは式（ａ１−１−０２）におけるＲ^１２およびｊとそれぞれ同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。］

[In formula (A1-8), R is the same as above, and the plurality of R may be the same or different from each other. R ¹¹ is the same as ^{R 11} in formula (a1-1-01). R ¹² and j are respectively the same as ^{R 12} and j in the formula (a1-1-02). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a0-1). ]

［式（Ａ１−９）中、Ｒは上記と同じであり、Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じであり、Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ０−１）におけるｅと同じである。複数のＲ、Ｒ^２１〜Ｒ^２３、ｅは相互に同じであっても異なっていてもよい。］

Wherein (A1-9), R is as defined ^{above, R 11} is the same as ^{R 11} in formula ^{(a1-1-01), R R 21 ~R} 23 is in the above formula (II) ²¹ To R ^23, and e is the same as e in the above formula (a0-1). A plurality of R, R ^{21 to} R ²³ and e may be the same as or different from each other. ]

The component (A1) is obtained by polymerizing a monomer for deriving each structural unit by known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. be able to.
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 1000 to 50000, more preferably 1500 to 30000, and 2500 to 20000. Most preferred. When it is smaller than the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist. When it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.
In the positive resist composition, the content of the component (A1) may be appropriately adjusted according to the resist film thickness to be formed.

<(A2) component>
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. Specific examples include those in which some of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable group.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a functional group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. Of course, it is not limited to these.
The acid dissociable group is not particularly limited, and examples thereof include those described above.

  In the component (A), as the component (A2), one type may be used alone, or two or more types may be used in combination.

In the positive resist composition, as the component (A), one type may be used alone, or two or more types may be used in combination.
The content of the component (A) in the positive resist composition may be adjusted according to the resist film thickness to be formed.

<(B) component>
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、置換基を有していてもよいアリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group which may have a substituent; R in the formula (b-1) Any one of ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula; R ⁴ ″ represents an alkyl group which may have a substituent, a halogen atom; An alkyl group, an aryl group or an alkenyl group; at least one of R ¹ ″ to R ³ ″ represents an aryl group and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and examples thereof include an aryl group having 6 to 20 carbon atoms. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The aryl group may have a substituent. “Having a substituent” means that part or all of the hydrogen atoms of the aryl group are substituted with a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, An alkoxyalkyloxy group, —O—R ⁵⁰ —C (═O) — (O) _n —R ⁵¹ , wherein R ⁵⁰ is an alkylene group or a single bond, and R ⁵¹ is an acid dissociable group or an acid non-dissociating group. N is 0 or 1. ] Etc. are mentioned.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

As the alkoxyalkyloxy group in which the hydrogen atom of the aryl group may be substituted, for example, —O—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ^{49 wherein} R ⁴⁷ and R ⁴⁸ are each It is independently a hydrogen atom or a linear or branched alkyl group, R ⁴⁹ is an alkyl group, and R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. However, at least one of R ⁴⁷ and R ⁴⁸ is a hydrogen atom. ].
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, preferably an ethyl group or a methyl group, and most preferably a methyl group.
One of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom, the other is preferably a hydrogen atom or a methyl group, and both R ⁴⁷ and R ⁴⁸ are particularly preferably hydrogen atoms.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms.
Specifically, a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. In this case, a cyclic group is formed by R ⁴⁸ , R ⁴⁹ , the oxygen atom to which R ⁴⁹ is bonded, and the carbon atom to which the oxygen atom and R ⁴⁸ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring.

In —O—R ⁵⁰ —C (═O) — (O) _n —R ⁵¹ in which the hydrogen atom of the aryl group may be substituted, the alkylene group for R ⁵⁰ is a linear or branched alkylene Group is preferable, and the number of carbon atoms is preferably 1 to 5. Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a 1,1-dimethylethylene group.
The acid dissociable group in R ⁵¹ is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid (an acid generated from the component (B) during exposure). For example, the structural unit (a11) or (a0- Examples thereof include the same acid dissociable groups as mentioned in the description of 1). Among them, the tertiary alkyl ester type is preferable.
Examples of the acid non-dissociable group in R ⁵¹ include a linear alkyl group which may have a substituent, and a branched alkyl group which may have a substituent (however, a tertiary alkyl group). A non-acid dissociable aliphatic cyclic group and the like. Examples of the non-acid-dissociable aliphatic cyclic group are the same as those described in the description of the structural unit (a4). Preferred acid non-dissociable groups include decyl group, tricyclodecanyl group, adamantyl group, 1- (1-adamantyl) methyl group, tetracyclododecanyl group, isobornyl group and norbornyl group.

The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
The alkyl group may have a substituent. “Having a substituent” means that part or all of the hydrogen atoms of the alkyl group are substituted with a substituent, and the substituent may be a substituent that the aryl group may have. The thing similar to what was mentioned as a group is mentioned.

In formula (b-1), any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when one or both of the two forming a ring is a cyclic group (cyclic alkyl group or aryl group), a polycyclic ring (fused ring) is formed when they are combined.
When two of R ¹ ″ to R ³ ″ are combined to form a ring, one ring containing a sulfur atom in the ring skeleton in the formula is a 3 to 10 membered ring including the sulfur atom. Of these, a 5- to 7-membered ring is particularly preferable.
Specific examples of the ring formed by combining two of R ¹ ″ to R ³ ″ include benzothiophene, dibenzothiophene, 9H-thioxanthene, thioxanthone, thianthrene, phenoxathiin, tetrahydrothiophenium, tetrahydro Examples include thiopyranium.
When any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one is preferably an aryl group.

Of the cation moiety of the compound represented by formula (b-1), when R ¹ ″ to R ³ ″ are all phenyl groups that may have a substituent, that is, the cation moiety is triphenylsulfonium. Specific examples of preferred skeletons include cation moieties represented by the following formulas (I-1-1) to (I-1-14).

  Moreover, what substituted a part or all of the phenyl group in these cation parts with the naphthyl group which may have a substituent is mentioned as a preferable thing. Of the three phenyl groups, 1 or 2 is preferably substituted with the naphthyl group.

Moreover, among the cation part of the compound represented by the formula (b-1), any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula. Preferable specific examples of the case include, for example, cation moieties represented by the following formulas (I-11-10) to (I-11-13).

［式中、Ｒ^９は、置換基を有していてもよいフェニル基、置換基を有していてもよいナフチル基または炭素数１〜５のアルキル基であり、Ｒ^１０は、置換基を有していてもよいフェニル基、置換基を有していてもよいナフチル基、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または水酸基であり、ｕは１〜３の整数である。］

[Wherein, R ⁹ is a phenyl group which may have a substituent, a naphthyl group which may have a substituent or an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ represents a substituent. A phenyl group which may have, a naphthyl group which may have a substituent, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms or a hydroxyl group, u is an integer of 1 to 3 It is. ]

［式中、Ｚ^４は単結合、メチレン基、硫黄原子、酸素原子、窒素原子、カルボニル基、−ＳＯ−、−ＳＯ_２−、−ＳＯ_３−、−ＣＯＯ−、−ＣＯＮＨ−または−Ｎ（Ｒ_Ｎ）−（該Ｒ_Ｎは炭素数１〜５のアルキル基である。）であり；Ｒ^４１〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[In the formula, Z ⁴ represents a single bond, a methylene group, a sulfur atom, an oxygen atom, a nitrogen atom, a carbonyl group, —SO—, —SO ₂ —, —SO ₃ —, —COO—, —CONH— or —N ( R _N ) — (wherein R _N is an alkyl group having 1 to 5 carbon atoms); R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl. N _{1 to} n ₅ are each independently an integer of 0 to 3, and n ₆ is an integer of 0 to 2. ]

In the formulas (I-11-10) to (I-11-11), in R ^{9 to} R ¹⁰ , the substituent that the phenyl group or naphthyl group may have may be represented by R ¹ ″ to R ³ ″. The thing similar to what was mentioned as a substituent which an aryl group may have is mentioned. As the substituent that the alkyl group have the ^{R 9 ~R 10, R 1 "} ~R 3" are the same as those of the substituent which may be alkyl groups have in the Can be mentioned.
u is an integer of 1 to 3, and 1 or 2 is most preferable.
In formulas (I-11-12) to (I-11-13), in R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and in particular, a linear or branched alkyl group A group is more preferable, and a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

In formulas (b-1) to (b-2), R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 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 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “optionally substituted” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a formula: XQ ^1- [wherein Q ¹ is a divalent linking group containing an oxygen atom, and X has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ⁴ ″ as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

X-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —, —C (═O) —O—R. ⁹³ —O—C (═O) — (wherein R ^{91 to} R ⁹³ are each independently an alkylene group).
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond. Among them, —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) — O—, —C (═O) —O—R ⁹³ — or —C (═O) —O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by XQ ^1- , the hydrocarbon group of X may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted by a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in X is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The “substituent containing a heteroatom” (hereinafter sometimes referred to as a heteroatom-containing substituent) may be composed only of the heteroatom, or may be a group containing a group other than the heteroatom or an atom. May be.

Examples of the hetero atom-containing substituent that may substitute a part of carbon atoms constituting the aliphatic hydrocarbon group include —O—, —C (═O) —O—, —C (═O) —. , —O—C (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S. -, -S (= O) _2- , -S (= O) _2- O- and the like. In the case of -NH-, the substituent (alkyl group, acyl group, etc.) that may substitute for H preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Particularly preferably, it has 1 to 5 carbon atoms.
When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.

Examples of the hetero atom-containing substituent that may substitute part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group include a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [ R ⁸⁰ is an alkyl group. ], -COOR ⁸¹ [R ⁸¹ is a hydrogen atom or an alkyl group. ], Halogenated alkyl groups, halogenated alkoxy groups, amino groups, amide groups, nitro groups, oxygen atoms (= O), sulfur atoms, sulfonyl groups (SO ₂ ) and the like.
Examples of the halogen atom as the heteroatom-containing substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The alkyl group in the alkoxy group as the heteroatom-containing substituent may be linear, branched or cyclic, or a combination thereof. The carbon number is preferably 1-30. When the alkyl group is linear or branched, the carbon number is preferably 1-20, more preferably 1-17, still more preferably 1-15, 10 is particularly preferred. Specific examples thereof include those similar to the specific examples of the linear or branched saturated hydrocarbon group exemplified below. When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkane, groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In these cycloalkyl groups, some or all of the hydrogen atoms bonded to the ring may or may not be substituted with a substituent such as a fluorine atom or a fluorinated alkyl group.
In —C (═O) —R ⁸⁰ and —COOR ⁸¹ as the hetero atom-containing substituent, the alkyl group in R ⁸⁰ and R ⁸¹ is the same as the alkyl group ^{exemplified as} the alkyl group in the alkoxy group. Can be mentioned.
Examples of the alkyl group in the halogenated alkyl group as the heteroatom-containing substituent include the same alkyl groups as mentioned for the alkyl group in the alkoxy group. As the halogenated alkyl group, a fluorinated alkyl group is particularly preferred.
Examples of the halogenated alkoxy group as the heteroatom-containing substituent include groups in which some or all of the hydrogen atoms of the alkoxy group have been substituted with the halogen atoms. The halogenated alkoxy group is preferably a fluorinated alkoxy group.
Examples of the hydroxyalkyl group as the heteroatom-containing substituent include groups in which at least one hydrogen atom of the alkyl group mentioned as the alkyl group in the alkoxy group is substituted with a hydroxyl group. The number of hydroxyl groups that the hydroxyalkyl group has is preferably 1 to 3, and most preferably 1.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group. As the unsaturated hydrocarbon group, a propenyl group is particularly preferable.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include groups represented by the following formulas (L1) to (L6) and (S1) to (S4).

［式中、Ｑ”は、酸素原子もしくは硫黄原子を含んでいてもよいアルキレン基、酸素原子または硫黄原子であり、ｍは０または１の整数である。］

[Wherein Q ″ is an alkylene group, an oxygen atom or a sulfur atom which may contain an oxygen atom or a sulfur atom, and m is an integer of 0 or 1.]

In the formula, the alkylene group in Q ″ is preferably linear or branched, and preferably has 1 to 5 carbon atoms. Specifically, a methylene group [—CH ₂ —]; —CH ( _{CH 3) -, - CH (} CH 2 CH 3) -, - C (CH 3) 2 -, - C (CH 3) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH ₃ )-, an alkylmethylene group such as —C (CH ₂ CH ₃ ) ₂ —; an ethylene group [—CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH _{3) -, - C (CH} 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 - alkyl groups such as, trimethylene group (n- propylene _{group) [- CH 2 CH 2 CH} 2 -] _{; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3 Tetramethylene group _{[-CH 2 CH 2 CH 2 CH} 2 -];; - CH 2 alkyltetramethylene groups such as _{- CH (CH 3) CH 2} CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 An alkyltetramethylene group such as CH ₂ —, a pentamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —], etc. Among these, a methylene group or an alkylmethylene group is preferable, and a methylene group, —CH (CH ₃ ) — or —C (CH ₃ ) ₂ — is particularly preferred.
The alkylene group may contain an oxygen atom (—O—) or a sulfur atom (—S—). Specific examples thereof include groups in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, and examples thereof include —O—R ⁹⁴ —, —S—R ⁹⁵ —, and —R ⁹⁶ —. O-R ^{<97 >} -, -R < ^{98 >} -S-R ^<99> -, etc. are mentioned. Here, R ^{94 to} R ⁹⁹ are each independently an alkylene group. Examples of the alkylene group include the same alkylene groups exemplified as the alkylene group for Q "Among _{them, -O-CH 2 -.,} - CH 2 -O-CH 2 -, - S-CH 2 - , —CH ₂ —S—CH ₂ — and the like are preferable.

In these aliphatic cyclic groups, some or all of the hydrogen atoms may be substituted with substituents. Examples of the substituent include an alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [R ⁸⁰ is an alkyl group. ], -COOR ⁸¹ [R ⁸¹ is a hydrogen atom or an alkyl group. ], Halogenated alkyl groups, halogenated alkoxy groups, amino groups, amide groups, nitro groups, oxygen atoms (= O), sulfur atoms, sulfonyl groups (SO ₂ ) and the like.
Examples of the alkyl group as the substituent include the same alkyl groups as those described above for the alkoxy group as the heteroatom-containing substituent.
As the alkyl group, an alkyl group having 1 to 6 carbon atoms is particularly preferable. The alkyl group is preferably linear or branched, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, Examples include pentyl group, isopentyl group, neopentyl group, hexyl group and the like. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
As the halogen atom, alkoxy group, —C (═O) —R ⁸⁰ , —COOR ⁸¹ , halogenated alkyl group, and halogenated alkoxy group as the substituent, a hydrogen atom constituting the aliphatic hydrocarbon group, respectively. The same thing as the thing quoted as the hetero atom containing substituent which may substitute a part or all of is mentioned.
Among the above, the substituent for substituting the hydrogen atom of the aliphatic cyclic group is preferably an alkyl group, an oxygen atom (= O), or a hydroxyl group.
The number of substituents possessed by the aliphatic cyclic group may be one or two or more. When having a plurality of substituents, the plurality of substituents may be the same or different.

X is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, and groups represented by the above (L2) to (L6) and (S3) to (S4). Etc. are preferred.

"- if it has a, ^{R 4} is ^{X-Q 1} as a substituent" as ^{the, X-Q 1 -Y 1 -} R 4 [ wherein, ^{Q 1} and X are as defined above, ^{Y 1} is a substituted group It is a C1-C4 alkylene group which may have, or a C1-C4 fluorinated alkylene group which may have a substituent. ] Is preferable.
In the group represented by XQ ¹ -Y ^1- , the alkylene group for Y ¹ includes the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate; bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate; triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate; dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropane sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of monophenyldimethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of diphenyl monomethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of di (1-naphthyl) phenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
In addition, the anion part of these onium salts is methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, 1-adamantanesulfonate, 2-norbornanesulfonate, d-camphor-10-sulfonate, benzenesulfonate, Onium salts substituted with alkyl sulfonates such as fluorobenzene sulfonate and p-toluene sulfonate can also be used.
Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1)-(b8) can also be used.

［式中、ｐは１〜３の整数であり、ｖ０は０〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、ｔ３は１〜３の整数であり、Ｒ^７は置換基であり、Ｒ^８は水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。］

[Wherein, p is an integer of 1 to 3, v0 is an integer of 0 to 3, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, and r1 ~r2 are each independently an integer of 0 to 3, g is an integer of 1 to 20, t3 is an integer from 1 to 3, ^{R 7} is a substituent, ^{R 8} is a hydrogen atom, the number of carbon atoms It is a 1-5 alkyl group or a C1-C5 halogenated alkyl group. ]

［式中、ｐ、Ｒ^７、Ｑ”はそれぞれ前記と同じであり、ｎ１〜ｎ５はそれぞれ独立に０または１であり、ｖ１〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数である。］

[Wherein, p, R ⁷ and Q ″ are the same as defined above, n1 to n5 are each independently 0 or 1, v1 to v5 are each independently an integer of 0 to 3, w1 to w5 Are each independently an integer of 0 to 3.]

Examples of the substituent for R ⁷ include an alkyl group and a heteroatom-containing substituent. Examples of the alkyl group include those similar to the alkyl group mentioned as the substituent that the aromatic hydrocarbon group may have in the description of X. In addition, the heteroatom-containing substituent is the same as the heteroatom-containing substituent that may substitute part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group in the description of X. Is mentioned.
Code (r1 and r2, w1 to w5) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.
Examples of the alkyl group and halogenated alkyl group for R ⁸ include the same alkyl groups and halogenated alkyl groups as those described above for R.
r1 to r2 and w1 to w5 are each preferably an integer of 0 to 2, and more preferably 0 or 1.
v0 to v5 are preferably 0 to 2, and most preferably 0 or 1.
t3 is preferably 1 or 2, and most preferably 1.
q3 is preferably 1 to 5, more preferably 1 to 3, and most preferably 1.

  Moreover, as an onium salt type | system | group acid generator, in the said general formula (b-1) or (b-2), an anion part is represented by the following general formula (b-3) or (b-4). An onium salt-based acid generator replaced with can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

In the general formula (b-1) or (b-2), the anion moiety (R ⁴ ″ SO ₃ ⁻ ) is R ⁷ ″ -COO ⁻ [wherein R ⁷ ″ is an alkyl group or a fluorinated alkyl group. An onium salt-based acid generator replaced with a cation group can be used (the cation moiety is the same as (b-1) or (b-2)).
Examples of R ⁷ ″ include the same as R ⁴ ″ described above.
Specific examples of the “R ⁷ ″ —COO ⁻ ” include trifluoroacetate ions, acetate ions, CF ₃ CF ₂ CF ₂ COO ⁻ , 1-adamantane carboxylate ions, and the like.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.
As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.
As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope Nthenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
0.5-50 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component in a resist composition, 1-40 mass parts is more preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

[(S ′) component]
The positive resist composition can be produced by dissolving the material in an organic solvent ((S ′) component).
As the component (S ′), any component can be used as long as it can dissolve each component to be used to form a uniform solution, and any one of conventionally known solvents for chemically amplified resists can be used. Or it can select and use 2 or more types suitably.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; many such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl lactate (EL), and γ-butyrolactone are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
Furthermore, as the component (S), a mixed solvent of the above-described mixed solvent of PGMEA and PGME and γ-butyrolactone is also preferable. In this case, as a mixing ratio, the mass ratio of the former and the latter is preferably 99.9: 0.1 to 80:20, more preferably 99.9: 0.1 to 90:10, Most preferably, it is 99.9: 0.1-95: 5. By setting it as the said range, the rectangularity of a resist pattern improves.

Further, when the component (S) contained in the pattern reversal composition is an ether organic solvent having no hydroxyl group, the component (S ′) is the above-described monohydric alcohol, dihydric alcohol, dihydric alcohol. Alcohol-based organic solvents such as alcohol derivatives may be used.
Specific examples of the alcohol-based organic solvent include propylene glycol (PG); 1-butoxy-2-propanol (PGB), n-hexanol, 2-heptanol, 3-heptanol, and 1-heptanol as those having a chain structure. 5-methyl-1-hexanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2- (2-butoxyethoxy) ethanol , N-pentyl alcohol, s-pentyl alcohol, t-pentyl alcohol, isopentyl alcohol, isobutanol (also referred to as isobutyl alcohol or 2-methyl-1-propanol, IBA), isopropyl alcohol, 2-ethylbutanol, neopentyl Alcoa , N- butanol, s- butanol, t-butanol, 1-propanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol (MIBC), and the like.
In addition, as those having a cyclic structure, cyclopentanemethanol, 1-cyclopentylethanol, cyclohexanol, cyclohexanemethanol (CM), cyclohexaneethanol, 1,2,3,6-tetrahydrobenzyl alcohol, exo-norbornol, 2-methyl Examples include cyclohexanol, cycloheptanol, 3,5-dimethylcyclohexanol, and benzyl alcohol.

  Among alcohol-based organic solvents, chain-structured monohydric alcohols or dihydric alcohol derivatives are preferred, such as 1-butoxy-2-propanol (PGB); isobutanol (also known as isobutyl alcohol or 2-methyl-1-propanol). IBA.), 4-methyl-2-pentanol (MIBC) and n-butanol are more preferred, and 1-butoxy-2-propanol (PGB) is most preferred.

  The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 5-15% by mass.

<Optional component>
[(D) component]
The positive resist composition further contains a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) as an optional component in order to improve the resist pattern shape, the stability over time, and the like. It is preferable to contain.
Since a wide variety of components (D) have already been proposed, any known one may be used. Cyclic amines, aliphatic amines, particularly secondary aliphatic amines and tertiary fats may be used. Group amines are preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms. Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n-heptylamine, Dialkylamines such as di-n-octylamine and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptyl Trialkylamines such as amine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n -Ok Noruamin, alkyl alcohol amines such as tri -n- octanol amine.
Of these, alkyl alcohol amines and trialkyl amines are preferred. Of the alkyl alcohol amines, triethanolamine and triisopropanolamine are particularly preferred. Of the trialkylamines, tri-n-pentylamine is particularly preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

[(E) component]
The positive resist composition comprises, as optional components, organic carboxylic acid, phosphorus oxo acid and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, stability with time, etc. At least one compound (E) selected from the group (hereinafter referred to as “component (E)”) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

[(F) component]
The positive resist composition may further contain, as an optional component, a polymer compound (F1) having a structural unit containing a base dissociable group (hereinafter referred to as the (F1) component).
In the present invention, since the component (F1) is contained, the dissolution rate in the organic solvent developer in the step (3) is increased. Therefore, the organic solvent developer of the positive resist composition and the pattern reversal composition This is preferable because the dissolution contrast with respect to the surface becomes large and a reversal pattern is easily formed.
Examples of the component (F1) include those described in US Patent Application Publication No. 2009/0197204.

  In the present invention, as the component (F1), those having the following structural units (fluorine-containing polymer compound (F1-1)) are particularly preferable.

［式（Ｆ１−１）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、複数のＲはそれぞれ同じであっても異なっていてもよい。ｊ”は０〜３の整数であり、Ｒ^３０は炭素数１〜５のアルキル基であり、ｈ”は１〜６の整数である。］

[In Formula (F1-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a plurality of R may be the same or different. Good. j ″ is an integer of 0 to 3, R ³⁰ is an alkyl group having 1 to 5 carbon atoms, and h ″ is an integer of 1 to 6. ]

In formula (F1-1), R is the same as R in the structural unit (a11).
j ″ is preferably 0 to 2, more preferably 0 or 1, and most preferably 0.
R ³⁰ is the same as the lower alkyl group having 1 to 5 carbon atoms in R, particularly preferably a methyl group or an ethyl group, and most preferably an ethyl group.
h ″ is preferably 3 or 4, and most preferably 4.

The mass average molecular weight (Mw) of the component (F1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 2000-100000, more preferably 3000-100000, and more preferably 4000-50000. Preferably, 5000 to 50000 is most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.8.

As the component (F1), one type may be used alone, or two or more types may be used in combination.
The content of the component (F1) in the positive resist composition is preferably 0.1 to 50 parts by weight, more preferably 0.3 to 40 parts by weight, with respect to 100 parts by weight of the component (A). -30 mass parts is especially preferable, and 0.1-15 mass parts is the most preferable. The hydrophobicity of the resist film formed using the positive resist composition is improved by setting it to the lower limit value or more of the above range, and has a hydrophobic property suitable for immersion exposure. If so, the lithography properties are improved.
Such component (F1) can also be suitably used as an additive for a resist composition when undergoing an immersion exposure process in step (1).
Moreover, by setting it as the lower limit value or more of the above range, the dissolution contrast between the positive resist composition and the pattern reversal composition with respect to the organic solvent developer in the step (3) increases, and it becomes easier to form a reversal pattern. preferable.

≪Pattern reversal composition≫
In the present invention, the pattern reversal composition contains the component (S) that does not dissolve the positive resist pattern.
As the pattern reversal composition, when the organic solvent development is performed, the positive resist pattern is removed, but any pattern reversal film that remains without being removed on the support may be formed. It is preferable that the base component (A ″) compatible with the component (S) is contained and no acidic compound that decomposes the acid-decomposable group of the component (A) is contained.
Furthermore, it is more preferable that the pattern reversal composition does not have an acid-decomposable group.

<(A ") component>
The substrate component (A ″) (hereinafter also referred to as “(A ″) component”) is an organic compound having film-forming ability.
The pattern reversal composition in the present invention is preferably a resin composition in which the component (A ″) contains a resin component (A ″ 1) (hereinafter also referred to as “(A ″ 1) component”).
Hereinafter, preferred embodiments of the component (A ″ 1) will be described more specifically.

<(A "1) component>
Examples of the component (A ″ 1) include a resin having a structural unit containing a polar group. By having a structural unit containing a polar group, the component (A ″ 1) is converted into the component (S). The solubility with respect to is improved. Among these (A ″ 1) components, preferred are a hydroxyl group, a cyano group, a carboxy group, a group represented by the following general formula (f2-0-1), a general formula (f2) as polar groups. -0-2) and a resin component having a structural unit (a ″ 1) containing at least one selected from the group consisting of groups represented by the following general formula (f2-0-3) It is done.

［式（ｆ２−０−１）中、Ｑは２価の連結基又は単結合であり、Ｒ^５はフッ素化アルキル基である。式（ｆ２−０−２）中、Ｑ及びＲ^５はいずれも前記と同じである。式（ｆ２−０−３）中、Ｒ^５１，Ｒ^５２はそれぞれ独立して水素原子、炭素数１〜５の低級アルキル基、フッ素原子、又は炭素数１〜５のフッ素化低級アルキル基であり、ｍ_ｆ，ｎ_ｆはそれぞれ独立して０〜５の整数（ただし、ｍ_ｆ＋ｎ_ｆ≧１）であり、ｑ’は０〜５の整数である。］

[In formula (f2-0-1), Q represents a divalent linking group or a single bond, and R ⁵ represents a fluorinated alkyl group. In formula (f2-0-2), Q and R ⁵ are the same as described above. In formula (f2-0-3), R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms. , M _f and n _f are each independently an integer of 0 to 5 (where m _f + n _f ≧ 1), and q ′ is an integer of 0 to 5. ]

-Structural unit (a "1):
The structural unit (a ″ 1) is represented by a hydroxyl group, a cyano group, a carboxy group, a group represented by the general formula (f2-0-1), or the general formula (f2-0-2) as a polar group. And a structural unit containing at least one selected from the group consisting of groups represented by general formula (f2-0-3).

"Group represented by general formula (f2-0-1)"
In the formula (f2-0-1), Q represents a divalent linking group or a single bond.
Examples of the divalent linking group include methylene group, ethylene group, propylene group, isopropylene group, cyclopropylene group, n-butylene group, isobutylene group, pentene group, isopentene group, neopentene group, cyclopentylene group, cyclohexane. C1-C8 linear, branched or cyclic alkylene groups, such as a hexylene group, a cycloheptylene group, and a cyclooctylene group, are mentioned. Further, the divalent linking group in Q may contain a hetero atom, such as an ether group, an ester group, a group in which at least one of a hydrogen atom and / or a carbon atom in the above-described alkylene group is substituted with a hetero atom, etc. Also mentioned. Among these, a linear alkylene group is preferable from the viewpoint of ease of synthesis, and a methylene group is particularly preferable.

R ⁵ is a fluorinated alkyl group. The fluorinated alkyl group is a group in which part or all of the hydrogen atoms of a linear, branched or cyclic alkyl group are substituted with fluorine atoms.
As such a linear or branched alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a pentyl group, an isopentyl group, and a neopentyl group, and a methyl group is particularly preferable.
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.
Among these, as the fluorinated alkyl group for R ^5, a linear or branched fluorinated alkyl group is preferable, a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable, and a hydrogen atom of the alkyl group is Particularly preferred are perfluoroalkyl groups all substituted with fluorine atoms. Specific examples of the perfluoroalkyl group include a trifluoromethyl group and a pentafluoroethyl group, and the trifluoromethyl group is most preferable.

"Group represented by general formula (f2-0-2)"
In the formula (f2-0-2), Q and R ⁵ are both the same as Q and R ⁵ in the formula (f2-0-1).

"Group represented by general formula (f2-0-3)"
In the formula (f2-0-3), R ⁵¹ and R ⁵² are each independently a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated lower alkyl group.
In R ⁵¹ and R ⁵² , the lower alkyl group having 1 to 5 carbon atoms is preferably a linear or branched lower alkyl group, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or an n-butyl group. , Isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like, and a methyl group is preferable.
In R ^{51, R 52,} as the fluorinated lower alkyl group of 1 to 5 carbon atoms, wherein at least one of the hydrogen atoms of the lower alkyl group ^{R 51, R 52} can be mentioned those substituted with a fluorine atom.
Among ^these, as R ^{51, R 52,} preferably is a hydrogen atom, and most preferably both hydrogen atoms.
m _f and n _f are each independently an integer of 0 to 5 (however, m _f + n _f ≧ 1), preferably an integer of 1 to 3, from the viewpoint of the dissolution rate in an organic solvent developer. , M _f and n _f are most preferably 1.
q ′ is an integer of 0 to 5, preferably an integer of 0 to 3, more preferably 0 or 1, and most preferably 1.

  Examples of the structural unit containing a group represented by the formula (f2-0-3) include a structural unit containing a group represented by the following general formula (f2-0-3-1).

［式中、Ｒ^５１，Ｒ^５２、ｍ_ｆ，ｎ_ｆ、ｑ’はそれぞれ上記と同様である。Ｒ^５３，Ｒ^５４はそれぞれ独立して水素原子、炭素数１〜５の低級アルキル基、フッ素原子、又は炭素数１〜５のフッ素化低級アルキル基であり、ｐ’は１〜５の整数である。］

[Wherein, R ⁵¹ , R ⁵² , m _f , n _f and q ′ are the same as described above. R ⁵³ and R ⁵⁴ are each independently a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms, and p ′ is an integer of 1 to 5. is there. ]

In the formula (f2-0-3-1), R ⁵³ and R ⁵⁴ may be the same as R ⁵¹ and R ⁵² , respectively. Of these, a hydrogen atom is preferable, and it is most preferable that both are hydrogen atoms.
p ′ is an integer of 1 to 5, preferably an integer of 1 to 3, more preferably 1 or 2, and particularly preferably 2.

  Among the above, the polar group in the structural unit (a ″ 1) is represented by a hydroxyl group, a group represented by the general formula (f2-0-1), and a general formula (f2-0-3). Particularly preferred is at least one selected from the group consisting of

  The structural unit (a ″ 1) is particularly preferably, for example, a structural unit derived from hydroxystyrene or a structural unit having a cyclic main chain (hereinafter referred to as “main chain cyclic structural unit”). The novolak resin among the cyclic main chain resins will be described later.

  In the present invention, the “main chain cyclic structural unit” has a monocyclic or polycyclic ring structure, and at least one, preferably two or more carbon atoms on the ring of the ring structure have a main chain. A constituent unit. By including the main chain cyclic structural unit, a pattern reversal film having high hydrophobicity on the film surface is obtained, and etching resistance is also improved. The reason for this is presumed that the carbon density is high due to the cyclic main chain.

  More specifically, examples of the structural unit (a ″ 1) include the following structural unit (a ″ 11) and structural unit (a ″ 12).

..Structural unit (a "11)
As the structural unit (a ″ 1), the solubility in the S component is good, and the solubility in the organic solvent developer is adjusted (the solubility of the pattern reversal film in the organic solvent developer is the positive type). It is easy to adjust the resist pattern to be less than the solubility in an organic solvent developer, and is excellent in etching resistance. Therefore, a structural unit represented by the following general formula (a ″ 11-1) "Structural unit (a" 11) ") can be suitably exemplified.

［式中、Ｒ^２０は水素原子又は炭素数１〜５のアルキル基であり；Ｒ^６は炭素数１〜５のアルキル基であり；ｐは１〜３の整数であり；ｑは０〜２の整数である。］

[Wherein, R ²⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ⁶ is an alkyl group having 1 to 5 carbon atoms; p is an integer of 1 to 3; q is 0 to 2] Is an integer. ]

In the formula (a ″ 11-1), as the alkyl group having 1 to 5 carbon atoms in R ²⁰ , specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert group -Linear or branched alkyl groups, such as a butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
R ²⁰ is particularly preferably a hydrogen atom or a methyl group.

p is an integer of 1 to 3, preferably 1.
The bonding position of the hydroxyl group may be any of the o-position, m-position and p-position of the phenyl group. When p is 1, the p-position is preferred because it is readily available and inexpensive. When p is 2 or 3, arbitrary substitution positions can be combined.

q is an integer of 0-2. Among these, q is preferably 0 or 1, and is preferably 0 industrially.
As the alkyl group for R ^6, the same alkyl groups as those for R ²⁰ can be used.
When q is 1, the substitution position of R ⁶ may be any of the o-position, m-position, and p-position. When q is 2, arbitrary substitution positions can be combined. At this time, the plurality of R ⁶ may be the same or different.

As the structural unit (a ″ 11), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
The proportion of the structural unit (a ″ 11) in the component (A ″ 1) is preferably 50 to 90 mol% based on the total of all structural units constituting the component (A ″ 1). It is more preferably mol%, and further preferably 60 to 80 mol%. If the proportion of the structural unit (a ″ 11) is not less than the lower limit of the range, the solubility in an organic solvent developer When the composition for pattern reversal becomes easy, a predetermined organic solvent solubility (to the extent that all of the pattern reversal composition film does not dissolve) is obtained, and when it is below the upper limit of the range, Good balance with other structural units.

..Structural unit (a "12)
The structural unit (a ″ 1) is derived from polycycloolefin because the etching resistance when the main chain is an acrylic skeleton (such as the structural unit (a3)) is superior to that of the pattern inversion film. The structural unit (hereinafter, this structural unit is referred to as “structural unit (a” 12) ”) can be preferably exemplified.
As the structural unit derived from polycycloolefin, a structural unit having a basic skeleton represented by the following general formula (a ″ 12-0 ′) is preferable.

［式中、ａ’は０又は１である。］

[Wherein a ′ is 0 or 1; ]

  In formula (a ″ 12-0 ′), a ′ is 0 or 1, and is preferably 0 in view of industrial availability.

In this specification, the “structural unit having the basic skeleton represented by the general formula (a ″ 12-0 ′)” is the structural unit represented by the general formula (a ″ 12-0 ′) (that is, bicyclo [2.2.1] -2-heptene structural unit derived from (norbornene), or tetracyclo ^{[4.4.0.1 2.5 .1.} 7.10] -3- configurations derived from dodecene Unit, and may have a substituent on the ring skeleton, that is, “a structural unit having a basic skeleton represented by the general formula (a ″ 12-0 ′)” , the carbon atoms constituting the ring skeleton (bicyclo [2.2.1] -2-heptane or tetracyclo ^{[4.4.0.1 2.5 .1.} 7.10] -3- dodecane) A part or all of the bonded hydrogen atoms are atoms or substituents other than hydrogen atoms. It shall also include substituted constitutional units.

  Preferred examples of the structural unit (a ″ 12) include structural units represented by general formula (a ″ 12-0) shown below.

［式中、Ｒ^６１〜Ｒ^６４はそれぞれ独立して水素原子、フッ素原子、直鎖状もしくは分岐鎖状のアルキル基、フッ素化アルキル基、前記一般式（ｆ２−０−１）で表される基、前記一般式（ｆ２−０−２）で表される基、又は前記一般式（ｆ２−０−３）で表される基である。ただし、Ｒ^６１〜Ｒ^６４のうち少なくとも一つは、前記一般式（ｆ２−０−１）で表される基、前記一般式（ｆ２−０−２）で表される基、又は前記一般式（ｆ２−０−３）で表される基である。ａ’は０又は１である。］

[Wherein, R ^{61 to} R ⁶⁴ each independently represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group, a fluorinated alkyl group, or the general formula (f2-0-1). A group represented by the general formula (f2-0-2), or a group represented by the general formula (f2-0-3). However, at least one of R ^{61 to} R ⁶⁴ is a group represented by the general formula (f2-0-1), a group represented by the general formula (f2-0-2), or the general formula It is a group represented by (f2-0-3). a ′ is 0 or 1; ]

  The structural unit represented by the formula (a ″ 12-0) is substituted at a specific position on the ring in the structural unit having the basic skeleton represented by the general formula (a ″ 12-0 ′). The group is represented by at least a group represented by the general formula (f2-0-1), a group represented by the general formula (f2-0-2), or the general formula (f2-0-3). It has a group.

  In the formula (a ″ 12-0), a ′ is the same as a ′ in the formula (a ″ 12-0 ′).

In the formula (a ″ 12-0), R ^{61 to} R ⁶⁴ each independently represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group, a fluorinated alkyl group, the general formula (f 2 − 0-1), a group represented by the general formula (f2-0-2), or a group represented by the general formula (f2-0-3).
In R ^{61 to} R ⁶⁴ , examples of the linear or branched alkyl group include the same as those exemplified in the description of the linear or branched alkyl group in R ⁵ .
In R ^{61 to} R ⁶⁴ , examples of the fluorinated alkyl group include those exemplified in the description of the fluorinated alkyl group for R ⁵ .
However, at least one of R ^{61 to} R ⁶⁴ is a group represented by the general formula (f2-0-1), a group represented by the general formula (f2-0-2), or the general formula It is a group represented by (f2-0-3), and is a group represented by the general formula (f2-0-1) or a group represented by the general formula (f2-0-3). More preferred.
Among them, at least one of R ^{61 to} R ⁶⁴ is a group represented by the general formula (f2-0-1), (f2-0-2), or formula (f2-0-3). More preferably, the remaining 0 to 3 are selected from a hydrogen atom and a linear or branched alkyl group.

  Specific examples of the structural unit (a ″ 12) include structural units represented by the following general formulas (a ″ 12-1 ′) to (a ″ 12-4 ′).

  In formulas (a ″ 12-1 ′) to (a ″ 12-4 ′), a ′ is the same as a ′ in formula (a ″ 12-0 ′).

In formula (a ″ 12-1 ′) and formula (a ″ 12-2 ′), c is an integer of 1 to 5, preferably 1 to 3, and most preferably 1.
b is an integer of 1-5, the integer of 1-3 is preferable and 1 is the most preferable.

In the formula (a ″ 12-3 ′), q ′ is the same as q ′ in the above formula (f2-0-3), and is most preferably 1.
m _{f, n f} is the same both as _m f, _{n f} in the formula (f2-0-3), and most preferably _{m f} and _{n f} are both 1.

In formula (a ″ 12-4 ′), q ′ is the same as q ′ in formula (f2-0-3), preferably 1.
m _{f, n f} is the same both as _m f, _{n f} in the formula (f2-0-3), preferably _{m f} and _{n f} are both 1.
p ′ is the same as p ′ in the above formula (f2-0-3-1), more preferably 1 or 2, and particularly preferably 2.

As the structural unit (a ″ 12), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
Among them, the structural unit (a ″ 12) is at least one selected from the group consisting of structural units represented by the general formulas (a ″ 12-1 ′) to (a ″ 12-2 ′). It is particularly preferred.
The proportion of the structural unit (a ″ 12) in the component (A ″ 1) is preferably 1 mol% or more, more preferably 5 mol% or more with respect to the total of all the structural units constituting the component (A ″ 1). 10 to 100 mol% is more preferable. When the proportion of the structural unit (a ″ 12) is not less than the lower limit of the range, the solubility in an organic solvent developer can be easily adjusted, and the pattern reversal composition In this case, predetermined organic solvent solubility is obtained.
More specifically, the structural unit represented by the formula (a ″ 12-1 ′) is preferably 1 to 50 mol% based on the total of all structural units constituting the component (A ″ 1). -45 mol% is more preferable, and 5-35 mol% is further more preferable. The structural unit represented by the formula (a ″ 12-2 ′) or the formula (a ″ 12-3 ′) is 15 to 15% of the total of all structural units constituting the component (A ″ 1). 80 mol% is preferable, 20 to 75 mol% is more preferable, and 25 to 75 mol% is more preferable, By making these ranges, the same effect as described above can be obtained.

  The monomer for deriving the structural unit (a ″ 12) can be synthesized, for example, by the technique disclosed in US Pat. No. 6,420,503.

-Structural unit (a "2):
The component (A ″ 1) is a structural unit other than the structural unit (a ″ 1) (hereinafter, this structural unit is referred to as “structural unit (a ″ 2)”) as long as the effects of the present invention are not impaired. ) May be included.
The structural unit (a ″ 2) is a structural unit that is not classified as the structural unit (a ″ 1) and is derived from a monomer that is copolymerizable with the monomer that derives the structural unit (a ″ 1). The unit is not particularly limited as long as it is a unit.

Examples of the structural unit (a ″ 2) include structural units that do not have a polar group. By including such a structural unit, the hydrophobicity of the pattern reversal film surface is improved, and an organic solvent developer. It is possible to control the solubility with respect to.
Specifically, a structural unit derived from styrene, a structural unit derived from a polycycloolefin having no substituent, and a structural unit derived from a polycycloolefin having a polycyclic alicyclic group as a substituent Etc.

“Structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene.
In this specification, “styrene” refers to styrene and those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group, and derivatives thereof (excluding the above-mentioned hydroxystyrene). Include concepts. Moreover, what substituted the hydrogen atom of the phenyl group with substituents, such as a C1-C5 alkyl group, etc. shall also be included.
By having a structural unit derived from styrene as the structural unit (a ″ 2), it is possible to adjust the solubility in an organic solvent developer. Resistance is improved.
Among the structural units derived from styrene, preferred are structural units represented by the following general formula (a ″ 21-1).

［式中、Ｒ^２０は前記と同じであり；Ｒ^４は炭素数１〜５のアルキル基であり；ｘは０〜３の整数である。］

[Wherein, R ²⁰ is the same as described above; R ⁴ is an alkyl group having 1 to 5 carbon atoms; x is an integer of 0 to 3; ]

"In ^{(21-1, R 20} is the formula (a Formula a)" is the same as ^{R 20} in 11-1).
In the formula (a ″ 21-1), examples of the alkyl group for R ⁴ include the same as the alkyl group for R ^{6 in} the general formula (a ″ 11-1).
x is an integer of 0 to 3, preferably 0 or 1, and industrially particularly preferably 0.
When x is 1, the substitution position of R ⁴ may be any of the o-position, m-position and p-position of the phenyl group. When x is 2 or 3, any substitution position can be combined. At this time, the plurality of R ⁴ may be the same or different.

Examples of the structural unit derived from a polycycloolefin having no substituent include bicyclo [2.2.1] -2-heptene (norbornene), tetracyclo [4.4.0.1 ^2.5 . 1. ^7.10 ] -3-dodecene and the like.
In addition, as a structural unit derived from a polycycloolefin having a polycyclic alicyclic group as a substituent, as a substituent on a ring of a structural unit derived from a polycycloolefin having no substituent, Examples include structural units having a polycyclic group such as a tricyclodecanyl group, an adamantyl group, and a tetracyclododecanyl group.

  When the structural unit (a ″ 2) described above is contained in the component (A ″ 1), the structural unit (a ″ 2) is added to the total of all structural units constituting the component (A ″ 1). It is preferable to contain -90 mol%, It is more preferable to contain 10-85 mol%, It is more preferable to contain 15-80 mol%. When it is at least the lower limit of the range, the effect of having the structural unit (a ″ 2) is enhanced, and when it is at most the upper limit, the balance with the structural unit (a ″ 1) is good.

  Further, as the structural unit (a ″ 2), in addition to those described above, structural units derived from a polycycloolefin having a fluorinated alkyl group as a substituent, specifically, the following general formula (a ″ 22- The structural unit represented by 1) is also included.

［式中、Ｒ^２７はフッ素化アルキル基であり；ａは０又は１である。］

[Wherein R ²⁷ is a fluorinated alkyl group; a is 0 or 1; ]

  In the formula (a ″ 22-1), a is 0 or 1, and is preferably 0 in consideration of industrial availability.

In the formula (a ″ 22-1), R ²⁷ is a fluorinated alkyl group, and a group in which part or all of the hydrogen atoms of the linear, branched or cyclic alkyl group are substituted with fluorine atoms. is there.
As a linear or branched alkyl group, a C1-C10 alkyl group is preferable, a C1-C8 alkyl group is more preferable, and a C1-C5 alkyl group is further more preferable. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a pentyl group, an isopentyl group, and a neopentyl group, and a propyl group is particularly preferable.
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.
Among the above, as the fluorinated alkyl group for R ^27, a group in which one hydrogen atom of a linear or branched alkyl group is substituted with a perfluoroalkyl group (an alkylene group is added to the perfluoroalkyl group). A bonded group), and — (CH ₂ ) _f —CF ₃ , — (CH ₂ ) _f —C ₂ F ₅ [f = 1 to 3] are more preferable, —CH ₂ —CF ₃ , —CH ₂ -C ₂ F ₅ are particularly preferred.

  The structural unit represented by the formula (a ″ 22-1) may have a substituent on the ring of the ring structure constituting the main chain. The substituent has 1 carbon atom. -5 lower alkyl groups, fluorine atoms, or fluorinated alkyl groups.

  When the structural unit represented by the formula (a ″ 22-1) is contained in the component (A ″ 1), the formula (A ″ 1) is added to the total of all the structural units constituting the component (A ″ 1). The structural unit represented by a ″ 22-1) is preferably contained in an amount of 5 to 75 mol%, more preferably 10 to 70 mol%, and further preferably 15 to 60 mol%. By setting it as the above range, the controllability of the dissolution rate in the organic solvent developer is excellent.

  The monomer for deriving the structural unit represented by the formula (a ″ 22-1) is, for example, a method disclosed in JP 2000-235263 A [fluorinated alkyl ester of (meth) acrylic acid and cyclohexane]. [Method of reacting pentadiene or dicyclopentadiene with Diels-Alder reaction, which is a known reaction].

In the present invention, the component (A ″ 1) preferably contains a resin component having the structural unit (a ″ 1) (hereinafter, this resin component is referred to as “(A ″ 1-1) component”).
The component (A ″ 1-1) preferably has no acid-decomposable group from the viewpoint of improving the stability as a composition (solution).
Preferred examples of the component (A ″ 1-1) include, for example, a copolymer composed of a plurality of structural units (a ″ 1), a structural unit (a ″ 1) and a structural unit (a ″ 2). The copolymer which consists of is mentioned.
Specifically, the copolymer composed of the structural unit (a ″ 1) and the structural unit (a ″ 2) is specifically represented by the structural unit (a ″ 11) and the general formula (a ″ 21-1). A copolymer composed of a unit and a copolymer composed of the structural unit (a ″ 12) and the structural unit represented by the general formula (a ″ 22-1) can be preferably exemplified.

As the component (A ″ 1), one type may be used alone, or two or more types may be used in combination.
In the present invention, as the component (A ″ 1), those containing the following combinations of structural units are particularly preferable.

［式中、Ｒ^２０、Ｒ^６、ｐ、ｑは、上記式（ａ”１１−１）におけるＲ^２０、Ｒ^６、ｐ、ｑとそれぞれ同様である。Ｒ^４、ｘは、上記式（ａ”２１−１）におけるＲ^４、ｘとそれぞれ同様である。複数のＲ^２０は同じであっても異なっていてもよい。］

^{Wherein, R 20, R 6, p} , q are, ^R 20 in the formula ^{(a "11-1), R 6} , p, respectively similar to the q ^.R 4, x is the equation (a The same as R ⁴ and x in “21-1)”. The plurality of R ²⁰ may be the same or different. ]

［式中、ｃ、ｂ、ｑ’、ｍ_ｆ、ｎ_ｆは、それぞれ上記と同様である。Ｒ^２７’は炭素数１〜５のフッ素化アルキル基である。］

[Wherein, c, b, q ′, m _f and n _f are the same as defined above. R ²⁷ ′ is a fluorinated alkyl group having 1 to 5 carbon atoms. ]

c is preferably an integer of 1 to 3, and most preferably 1.
b is preferably an integer of 1 to 3, and most preferably 1.
q ′ is preferably an integer of 0 to 3, more preferably 0 or 1, and most preferably 1.
m _f and n _f are preferably integers of 1 to 3, and most preferably m _f and n _f are both 1.
R ²⁷ ′ is particularly preferably —CH ₂ —CF ₃ or —CH ₂ —C ₂ F ₅ .

The mass average molecular weight (Mw) of the component (A ″ 1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, It is most preferably 2000 to 20000. If it is not more than the upper limit of this range, it has sufficient solubility in an organic solvent to be used as a resin component for forming the film for pattern reversal, and is not less than the lower limit of this range. The dry etching resistance and the pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A ″ 1) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.0 to 2. 5 is most preferred.

The component (A ″ 1) is obtained, for example, by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN). Can do.
Moreover, when it has a main chain cyclic | annular structural unit, (A "1) component is compoundable by the method as described in Unexamined-Japanese-Patent No. 2006-291177, for example.

Examples of the component (A ″) other than the above-described resin component include novolac resins.

As the novolak resin, those obtained by reacting phenols and aldehydes in the presence of an acidic catalyst can be used.
The novolak resin is preferable because it has a slight solubility in an organic solvent developer during development, can be easily controlled to a predetermined dissolution rate, and the main chain has excellent etching resistance. In terms of etching resistance, a novolac resin is preferably used because it is superior to a resin having any one of the structural units (a3) and (a ″ 11) to (a ″ 12).
Examples of the phenols include phenol; cresols such as m-cresol, p-cresol, and o-cresol; 2,3-dimethylphenol, 2,5-dimethylphenol, 3,5-dimethylphenol, 3,4- Dimethylphenols such as dimethylphenol; m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol, 2,3,5-triethylphenol, 4-tert-butylphenol, 3-tert -Alkylphenols such as butylphenol, 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2-tert-butyl-5-methylphenol; p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-e Alkoxyphenols such as xylphenol, p-propoxyphenol, m-propoxyphenol; o-isopropenylphenol, p-isopropenylphenol, 2-methyl-4-isopropenylphenol, 2-ethyl-4-isopropenylphenol, etc. Isopropenyl phenols; arylphenols such as phenylphenol; polyhydroxyphenols such as 4,4′-dihydroxybiphenyl, bisphenol A, resorcinol, hydroquinone, pyrogallol, and the like. Among these, 3,4-dimethylphenol, 2,3,5-trimethylphenol, m-cresol, and p-cresol are particularly preferable.
The said phenols may be used individually by 1 type, or may be used in combination of 2 or more type. Among these, it is preferable to use a combination of two or more, and it is preferable to use a combination of two or more selected from 3,4-dimethylphenol, 2,3,5-trimethylphenol, m-cresol, and p-cresol. Particularly preferred.
Examples of the aldehydes include conventionally known aldehydes such as formaldehyde, paraformaldehyde, trioxane, and acetaldehyde, and formaldehyde is preferable.
Examples of the acidic catalyst include hydrochloric acid, sulfuric acid, formic acid, oxalic acid, paratoluenesulfonic acid, and the like, and oxalic acid is preferable.

In the pattern reversal composition in the present invention, as the component (A ″), one type may be used alone, or two or more types may be used in combination.
The content of the component (A ″) in the pattern reversal composition may be adjusted according to the film thickness to be formed.

[Optional ingredients]
In addition to the above components (S) and (A ″), the pattern reversal composition may further contain miscible additives, for example, an additional resin for improving the performance of the pattern reversal film. A surfactant, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like for improving the coating property can be appropriately added and contained.

Specific examples of the dissolution inhibitor include onium salt-based acid generators exemplified in the description of the component (B) blended in the positive resist composition described above. Among them, the compound represented by the above formula (b-1) is preferable because it can be easily controlled to a predetermined dissolution rate and the solubility can be easily adjusted.
A dissolution inhibitor may be used individually by 1 type, and may use 2 or more types together.
The content of the dissolution inhibitor in the pattern reversal composition is preferably 0 to 25 parts by mass, more preferably 0.1 to 20 parts by mass, and 0.5 to 18 parts by mass with respect to 100 parts by mass of the component (A ″). When the content is within the above range, the film for pattern reversal is sufficiently formed, and a uniform solution can be obtained and the storage stability is improved, which is preferable.

The pattern reversal composition in the present invention is not limited to the resin composition containing the component (A ″ 1) described above, and a non-chemically amplified positive resist composition may be used.
This non-chemically amplified positive resist composition includes (S) component, a polar group-containing resin such as novolac resin and hydroxystyrene resin, which has been used in radiation-sensitive compositions, and naphtho. And a resist composition containing a photosensitive component such as a quinonediazide group-containing compound. The resist composition may contain a sensitizer as necessary.

  According to the pattern forming method of the present invention described above, a finer reversal pattern can be easily formed.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

<Synthesis of resin component (A)>
The polymer compound 1 as the component (A1) used in the examples was synthesized using monomers (1) to (4) represented by the following chemical formula. For the polymer compound, the mass average molecular weight (Mw) and the molecular weight dispersity (Mw / Mn) are values in terms of standard polystyrene determined by GPC measurement, and the copolymer composition ratio (molar ratio) is carbon 13 nuclear magnetism. It was determined by resonance spectrum (600MHz_ ¹³ C-NMR).

[Ｍｗ：７０００、Ｍｗ／Ｍｎ：１．７０、モル比：ｌ／ｍ／ｎ／ｏ＝２５／４５／１５／１５]

[Mw: 7000, Mw / Mn: 1.70, molar ratio: 1 / m / n / o = 25/45/15/15]

<Preparation of resist composition>
Each component shown in Table 1 was mixed and dissolved to prepare a resist composition.

In Table 1, the numerical value in [] shows a compounding quantity (part by mass). Moreover, the symbol in Table 1 shows the following, respectively.
(A) -1: the polymer compound 1
(B) -1: Compound represented by the following chemical formula (B) -1 (D) -1: Tri-n-pentylamine (E) -1: Salicylic acid (F) -1: Formula (F) -1 (Mw: 12000, dispersity: 1.5).
(S ′)-1: 1-butoxy-2-propanol

<Preparation of pattern reversal composition>
The components shown in Table 2 were mixed and dissolved to prepare a pattern reversal composition 1.

Each abbreviation in Table 2 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -2: m-cresol / 3,4-dimethylphenol = 80/20 (molar ratio) mixed phenols are subjected to a condensation reaction by a conventional method using formaldehyde as a condensing agent and an oxalic acid catalyst. A novolak resin having a Mw of 8900, obtained by subjecting the novolak resin thus obtained to a fractionation treatment with a water-methanol mixed solvent.

  (S) -2: Mixed solvent of dibutyl ether (DBE) and 4-methyl-2-pentanol (MIBC) (DBE: MIBC = 90: 10 (mass ratio)).

<Formation of reverse pattern>
Using the resists 1 and 2 as a positive resist composition and the pattern reversal composition 1 as a pattern reversal composition, a reversal pattern was formed as follows.

Example 1
[Step (1)]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed.
The resist 1 is coated on the organic antireflection film using a spinner, pre-baked (PAB) at 120 ° C. for 60 seconds on a hot plate, and dried to obtain a resist film having a thickness of 80 nm. (Positive resist film) was formed.
Next, a line having a line width of 150 nm / pitch of 300 nm is applied to the positive resist film using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination). The positive resist film was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone) targeting an and-space resist pattern (hereinafter referred to as “LS pattern”). .
Then, a post-exposure heating (PEB) treatment was performed at 90 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, Tokyo Ohka Kogyo Co., Ltd.) For 30 seconds, and then post-baked at 140 ° C. for 60 seconds.
As a result, an LS pattern (hereinafter referred to as “LS pattern (a-1)”) in which lines having a width of 150 nm are arranged at equal intervals (pitch: 300 nm) was formed on the positive resist film.

[Step (2)]
Next, the pattern reversal composition 1 is applied onto the organic antireflection film on which the LS pattern (a-1) is formed using a spinner, and is heated on a hot plate at 130 ° C. for 60 seconds. By performing pre-baking (PAB) and drying, a resist film (pattern inversion film) having a film thickness of 100 nm was formed.

[Step (3)]
Next, the organic solvent development for 10 seconds was performed using butyl acetate at 23 degreeC.

  As a result, the line portion of the LS pattern (a) formed on the positive resist film is dissolved and removed in butyl acetate, and the space portion of the LS pattern (a) is derived from the pattern inversion film. As a result, a reverse pattern of the LS pattern (a-1), that is, a space-and-line resist pattern (hereinafter referred to as “SL pattern”) having a space width of about 150 nm / pitch of about 300 nm is formed. .

(Example 2)
[Process (1)]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed. Then, the resist composition 2 is applied onto the antireflection film using a spinner, prebaked (PAB) on a hot plate at 120 ° C. for 60 seconds, and dried. A resist film having a thickness of 80 nm was formed.
Next, an ArF excimer laser (193 nm) is applied to the resist film through a mask pattern using an ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon; NA (numerical aperture) = 1.07, σ0.97). ) Was selectively irradiated. Then, PEB treatment is performed at 90 ° C. for 60 seconds, and further development processing is performed with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 30 seconds, and then pure water is used for 30 seconds. Rinse with water and shake off to dry.
As a result, an LS pattern (hereinafter referred to as “LS pattern (a-2)”) in which lines having a width of 55 nm are arranged at equal intervals (pitch 110 nm) was formed on the positive resist film.
[Step (2)]
Next, the pattern reversal composition 1 is applied onto the organic antireflection film on which the LS pattern (a-2) is formed using a spinner, and is heated on a hot plate at 130 ° C. for 60 seconds. By performing pre-baking (PAB) and drying, a resist film (pattern inversion film) having a film thickness of 100 nm was formed.

[Step (3)]
Next, the organic solvent development for 10 seconds was performed using butyl acetate at 23 degreeC.

  As a result, the line portion of the LS pattern (a-2) formed on the positive resist film is removed by dissolving in butyl acetate, and the pattern inversion is applied to the space portion of the LS pattern (a-2). By forming a line derived from the film for use, an inverted pattern of the LS pattern (a-2), that is, an SL pattern having a space width of about 55 nm / pitch of about 110 nm was formed.

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... Positive resist pattern, 6 ... Film for pattern inversion

Claims (8)

A step (1) of forming a positive resist pattern on the support with one or more positive resist compositions whose solubility in an alkaline developer increases upon exposure;
A process of forming a pattern reversal film by applying a pattern reversal composition containing an organic solvent (S) that does not dissolve the positive resist pattern on the support on which the positive resist pattern is formed (2) )When,
A step (3) of removing the positive resist pattern to form a resist pattern by developing the pattern reversal film using an organic solvent developer that dissolves the positive resist pattern. A forming method comprising:
The positive resist composition contains an acid generator component (B) that generates an acid upon exposure and a base material component (A) having an acid-decomposable group, and the pattern reversal composition comprises the organic It contains a base material component (A ″) that is compatible with the solvent (S), and does not contain an acidic compound that decomposes the acid-decomposable group of (A),
The substrate component (A ″) is represented by a hydroxyl group, a cyano group, a carboxy group, a group represented by the following general formula (f2-0-1), or a general formula (f2-0-2) below as a polar group. And a resin component having a structural unit (a ″ 1) containing at least one selected from the group consisting of a group represented by the following general formula (f2-0-3):
At the time of development in the step (3), the pattern forming method is characterized in that the solubility of the pattern reversal film in the organic solvent developer is smaller than the solubility of the positive resist pattern in the organic solvent developer.

[In formula (f2-0-1), Q represents a divalent linking group or a single bond, and R ⁵ represents a fluorinated alkyl group. In formula (f2-0-2), Q and R ⁵ are the same as described above. In formula (f2-0-3), R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms. , M _f and n _f are each independently an integer of 0 to 5 (where m _f + n _f ≧ 1), and q ′ is an integer of 0 to 5. ] The pattern forming method according to claim 1 , wherein the base material component (A ″) does not have an acid-decomposable group. The organic solvent (S) The pattern forming method according to claim 1 or 2 is an ether-based organic solvent having no alcoholic organic solvent or a hydroxyl group. The base component (A) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and an acid whose polarity is increased by the action of an acid the pattern forming method according to any one of claims 1 to 3 containing a resin component (A1) having a structural unit containing a decomposable group (a1). The resin component (A1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a lactone-containing cyclic group the structural unit (a2 ^L) and -SO 2 _- pattern forming method according to claim 4 having the structure units of at least one selected from the group consisting of structural units containing containing cyclic group (a2 ^S). The resin component (A1) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and the polar group-containing aliphatic hydrocarbon group The pattern formation method of Claim 4 or 5 which has a structural unit (a3) containing. The positive resist pattern, line pattern and / or pattern forming method according to any one of claims 1 to 6 including the dot pattern. The exposure, a pattern forming method according to any one of claims 1 to 7, which is a liquid immersion exposure.

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