JP7472917B2 - Pattern forming method, radiation-sensitive composition and inclusion compound - Google Patents

Description

The present invention relates to a pattern forming method, a radiation-sensitive composition and an inclusion compound.

Radiation-sensitive compositions containing a polymer having a polymerizable group, a crosslinking agent, and a polymerization initiator are widely known as negative pattern-forming materials used as display element forming materials, semiconductor resists, etc. (see Patent Documents 1 to 3). In such radiation-sensitive compositions, a crosslinked polymer having a three-dimensional network structure is formed by crosslinking, and it is said that a pattern excellent in heat resistance, solvent resistance, etching resistance, etc. can be obtained. However, conventional radiation-sensitive compositions such as those described above have the disadvantage that the crosslinked polymer formed swells during development, causing pattern defects, and the pattern shrinks after crosslinking and hardening. In addition, various characteristics are required for the pattern-forming material and the pattern formed according to the application, etc. Therefore, there is a demand for the development of a new pattern-forming material and a pattern-forming method that can form a pattern with physical properties, performance, etc. different from conventional ones.

JP 2014-48428 A JP 2013-200431 A JP 2012-150180 A

The present invention has been made based on the above circumstances, and aims to provide a pattern formation method using a novel pattern formation material, a radiation-sensitive composition that can be used as a novel pattern formation material, and an inclusion compound that is suitable as a component of such a radiation-sensitive composition.

One aspect of the invention made to solve the above problem is a pattern formation method comprising the steps of forming a coating film on a substrate from a radiation-sensitive composition containing a polymer having a host group and a first guest compound, exposing the coating film to light, and developing the coating film after exposure, wherein the host group is a monovalent group in which one hydrogen atom or hydroxyl group has been removed from a cyclodextrin derivative.

Another aspect of the present invention is a radiation-sensitive composition for pattern formation, which contains a polymer having a host group and a first guest compound, and the host group is a monovalent group obtained by removing one hydrogen atom or hydroxyl group from a cyclodextrin derivative.

Another aspect of the present invention is an inclusion compound in which at least a portion of a first guest compound is included in the host group of a polymer having a host group, the host group being a monovalent group in which one hydrogen atom or hydroxyl group has been removed from a cyclodextrin derivative, the cyclodextrin derivative having a structure in which the hydrogen atom of at least one hydroxyl group in the cyclodextrin is substituted with at least one group selected from the group consisting of a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, and -CONHR, where R is a methyl group or an ethyl group, and the first guest compound is an inclusion compound having a crosslinkable group and a hydrocarbon group having 6 to 30 carbon atoms.

According to any of the aspects of the present invention, it is possible to provide a pattern formation method using a novel pattern formation material, a radiation-sensitive composition that can be used as a novel pattern formation material, and an inclusion compound that is suitable as a component of such a radiation-sensitive composition.

A preferred embodiment of the present invention will be described in detail below. Note that the present invention is not limited to the embodiment described below, and should be understood to include various modifications that are implemented within the scope of the present invention.

<Radiation-sensitive composition>
A radiation-sensitive composition according to one embodiment of the present invention contains a polymer having a host group (polymer [A]) and a first guest compound (guest compound [G1]). The radiation-sensitive composition is a composition for forming a pattern. In a preferred embodiment of the radiation-sensitive composition, at least a part of the guest compound [G1] is encapsulated in the host group of the polymer [A]. In this case, a free guest compound [G1] that is not encapsulated in the host group of the polymer [A] may be present. The guest compound [G1] may have a guest group, and this guest group may be encapsulated in the host group of the polymer [A]. The entire guest compound [G1] may be encapsulated in the host group of the polymer [A].

It is preferable that the [G1] guest compound is, in its first preferred form, a compound having a crosslinkable group ([G1-1] crosslinkable compound) or, in its second preferred form, a photoreactive compound ([G1-2] photoreactive compound).

In a first preferred embodiment, when the guest compound [G1] is a crosslinkable compound [G1-1], the polymer [A] and the crosslinkable compound [G1-1] can form an inclusion compound in which a part of the crosslinkable compound [G1-1] (usually a part other than the crosslinkable group) is included in the host group of the polymer [A]. Such an inclusion compound functions as a polymer having a crosslinkable group, and exhibits photocurability when used in combination with, for example, a radiation-sensitive polymerization initiator [C]. For this reason, a pattern can be formed by exposure and development.

That is, in the first preferred embodiment, the radiation-sensitive composition preferably contains the polymer [A], the guest compound [G1] which is the included crosslinkable compound [G1-1], and the radiation-sensitive polymerization initiator [C], and more preferably further contains the polymerizable compound [B]. An example of the first preferred embodiment is shown in the following scheme. In the following example, the adamantyl group of the adamantyl acrylate which is the crosslinkable compound [G1-1] is included in the host group (αCD) of the polymer [A] to form an inclusion compound. By irradiating with radiation in the presence of the radiation-sensitive polymerization initiator [C] (not shown in the following scheme), a crosslinked structure is formed by a chemical reaction between the acryloyl group of the adamantyl acrylate which is the crosslinkable compound [G1-1] constituting the inclusion compound and the vinyl group of the 1,2-divinylcyclobutane which is the polymerizable compound [B], and hardening occurs. Alternatively, the composition may be one in which the polymerizable compound [B] is not present, and the acryloyl groups of the adamantyl acrylate, which is the crosslinkable compound [G1-1] constituting the inclusion compound, react with each other to form a crosslinked structure through a chemical reaction, thereby causing hardening.

In a second preferred embodiment, when the guest compound [G1] is a photoreactive compound [G1-2], radiation is irradiated to a coating of a radiation-sensitive composition containing a polymer [A] and a photoreactive compound [G1-2], causing the photoreactive compound [G1-2] to react and changing the solubility of the radiation-irradiated portion in a developer. This allows a pattern to be formed by exposure and development. For example, when the photoreactive compound [G1-2] is a photoisomerizable compound, the polymer [A] and the photoreactive compound [G1-2] (photoisomerizable compound) can form an inclusion compound in which at least a part of the photoreactive compound [G1-2] is included in the host group of the polymer [A]. When the photoreactive compound [G1-2] (photoisomerizable compound) in such an inclusion compound is irradiated with radiation, the photoreactive compound [G1-2] (photoisomerizable compound) is isomerized and released from the host group. In the radiation-sensitive composition, when a polymer having a guest group (the [G2] polymer) is further contained as a second guest compound (the [G2] guest compound) in a state where it is not encapsulated, the host group encapsulates the guest group of the [G2] polymer while the [G1-2] photoreactive compound (photoisomerizable compound) is released from the host group, and the [A] polymer and the [G2] polymer form a crosslinked structure due to host-guest interaction. In this way, for example, a radiation-sensitive composition containing the [A] polymer, the [G1-2] photoreactive compound, and the [G2] polymer exhibits photocurability and can form a pattern by exposure and development.

That is, in the second preferred embodiment, the radiation-sensitive composition preferably contains the polymer [A], the guest compound [G1] which is the encapsulated photoreactive compound [G1-2], and the guest compound [G2] which is the unencapsulated polymer [G2]. An example of the second preferred embodiment is shown in the following schematic diagram. In the following example, the host group of the polymer [A] encapsulates the photoreactive compound [G1-2] azobenzene (trans form) to form an inclusion compound. When such an inclusion compound is irradiated with radiation, the photoreactive compound [G1-2] azobenzene is isomerized to a cis form and released from the host group, and the guest group (adamantyl group) of the polymer [G2] is encapsulated in the host group, and the polymer [A] and the polymer [G2] form a crosslinked structure due to host-guest interaction.

In this way, the radiation-sensitive composition preferably utilizes the host group of the polymer [A] and the guest compound [G1] or the guest compound [G2] to form a crosslinked structure by a chemical reaction or a host-guest interaction accompanying radiation exposure, and can be used as a pattern-forming material. In addition, as described below, by selecting the type of the guest compound [G1] and the guest compound [G2], and the guest group they have, the properties required of a pattern-forming material, such as sensitivity, exposure margin, depth of focus, LWR (Line Width Roughness), film loss, and heat resistance, are improved. The radiation-sensitive composition is particularly useful as a negative pattern-forming material. Each component will be described in detail below.

<Polymer (A)>
The polymer (A) has a host group.

(Structural Unit (I))
The polymer (A) preferably contains a structural unit (I) having a host group. The host group has a structure capable of encapsulating at least a part of the guest compound (G1).

The host group is a monovalent group in which one hydrogen atom or hydroxyl group has been removed from a cyclodextrin derivative, and a group in which one hydroxyl group has been removed from a cyclodextrin derivative is preferred.

A cyclodextrin derivative is one in which the hydrogen atom of a hydroxyl group of cyclodextrin is replaced with a substituent. Examples of the substituent include a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, -CONHR, etc., where R is a methyl group or an ethyl group. In other words, the cyclodextrin derivative is preferably one having a structure in which the hydrogen atom of a hydroxyl group of cyclodextrin is replaced with at least one group (substituent) selected from the group consisting of a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group, and -CONHR.

Examples of monovalent hydrocarbon groups having 1 to 12 carbon atoms include monovalent linear hydrocarbon groups having 1 to 12 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 12 carbon atoms, and monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms.

Examples of monovalent chain hydrocarbon groups having 1 to 12 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl groups, alkenyl groups such as ethenyl, propenyl, and butenyl groups, and alkynyl groups such as ethynyl, propynyl, and butynyl groups.

Examples of monovalent alicyclic hydrocarbon groups having 3 to 12 carbon atoms include monovalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl and cyclohexyl groups, monovalent monocyclic unsaturated hydrocarbon groups such as cyclopentenyl and cyclohexenyl groups, monovalent polycyclic saturated alicyclic hydrocarbon groups such as norbornyl and adamantyl groups, and monovalent polycyclic unsaturated alicyclic hydrocarbon groups such as norbornenyl groups.

Examples of monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms include phenyl groups, tolyl groups, and naphthyl groups.

Examples of acyl groups having 1 to 12 carbon atoms include a formyl group, an acetyl group, a propionyl group, and a benzoyl group. As the acyl group, an acyl group having 1 to 8 carbon atoms is preferred.

Among these substituents, monovalent hydrocarbon groups having 1 to 12 carbon atoms are preferred, and monovalent hydrocarbon groups having 1 to 4 carbon atoms are more preferred.

In the host group (a monovalent group obtained by removing one hydrogen atom or hydroxyl group from a cyclodextrin derivative), the number of groups in which the hydrogen atoms of hydroxyl groups are replaced with substituents relative to the total number of hydroxyl groups and groups in which the hydrogen atoms of hydroxyl groups are replaced with substituents is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. In such a case, the host group can exhibit excellent affinity (inclusion ability) particularly for the hydrophobic [G1] guest compound or hydrophobic guest group.

The cyclodextrin is not particularly limited as long as it is a cyclic oligosaccharide in which multiple D-glucose units are linked by α-1,4 glycosidic bonds to form a cyclic structure. Of the cyclodextrins, at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin is preferred. By using such a cyclodextrin, it is possible to exhibit good inclusion properties for an appropriate [G1] guest compound, and effective release properties upon light irradiation in a state in which a [G1-2] photoreactive compound (photoisomerizable compound) is encapsulated.

That is, a suitable host group is a group represented by the following formula (H). The group represented by formula (H) is an example of a group in which one hydroxyl group has been removed from a cyclodextrin derivative.

In formula (H), each of the multiple R ^a's is independently a hydrogen atom or a substituent. The substituent is a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, or -CONHR. Here, R is a methyl group or an ethyl group. At least one of the multiple R ^a 's is the above-mentioned substituent. p is 5, 6, or 7. * represents a bonding site.

An example of structural unit (I) is a structural unit represented by the following formula (1):

In formula (1), R ¹ is a hydrogen atom or a methyl group. R ² is a divalent linking group. R ³ is a group represented by -O- or -NR ⁴ - (R ⁴ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms). R ^H is a host group.

Examples of the divalent linking group represented by ^R2 include -O-, -S-, -CO-, -CS-, -SO-, -SO ₂ -, -NR ^b -, substituted or unsubstituted divalent hydrocarbon groups, and divalent groups combining two or more of these. R ^b is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^b is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a methyl group.

Examples of divalent hydrocarbon groups include divalent hydrocarbon groups having 1 to 20 carbon atoms. Examples of divalent hydrocarbon groups having 1 to 20 carbon atoms include divalent linear hydrocarbon groups having 1 to 20 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, and divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

Examples of divalent linear hydrocarbon groups having 1 to 20 carbon atoms include alkanediyl groups such as methanediyl, ethanediyl, propanediyl, and butanediyl groups, alkenediyl groups such as ethenediyl, propenediyl, and butenediyl groups, and alkynediyl groups such as ethynediyl, propynediyl, and butynediyl groups.

Examples of divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include divalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentanediyl groups and cyclohexanediyl groups, divalent monocyclic unsaturated hydrocarbon groups such as cyclopentenediyl groups and cyclohexenediyl groups, divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornanediyl groups, adamantanediyl groups and tricyclodecanediyl groups, and divalent polycyclic alicyclic unsaturated hydrocarbon groups such as norbornenediyl groups and tricyclodecenediyl groups.

Examples of divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include arenediyl groups such as benzenediyl, toluenediyl, xylylenediyl, naphthalenediyl, and anthracenediyl groups, and arenediylalkanediyl groups such as benzenediylmethanediyl, benzenediylethanediyl, naphthalenediylmethanediyl, and anthracenediylmethanediyl groups.

Examples of substituents on divalent hydrocarbon groups include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, hydroxy groups, amino groups, and carboxy groups.

The divalent linking group represented by ^R2 preferably has 0 to 30 carbon atoms, and more preferably has 1 to 20 carbon atoms.

Preferred examples of the divalent linking group represented by ^R2 include groups represented by the following formulas (2a) to (2f).
-CO- (2a)
-COO-R"- (2b)
-CONR'-R"- (2c)
—COO-R″-NR′-CO- (2d)
-CONR'-R"-NR'-CO- (2e)
-R"- (2f)

In the above formulas (2a) to (2f), each R' is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Each R" is independently a divalent hydrocarbon group having 1 to 20 carbon atoms.

R' is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group.

Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms represented by R" include the same divalent hydrocarbon groups having 1 to 20 carbon atoms exemplified as the divalent linking group represented by ^R2 . A preferred form of R" is a divalent hydrocarbon group represented by -Ph _n -(CH ₂ ) _m - (Ph is a phenylene group, n is 0 or 1, and m is an integer of 0 to 4, with the proviso that either n or m is an integer of 1 or greater).

Examples of the host group represented by R 1 ^H include those described above, such as the group represented by formula (H).

[A] The polymer can be obtained by polymerizing a monomer containing a monomer (I) that gives the structural unit (I) by a known method. One or more types of monomer (I) can be used.

An example of the monomer (I) that provides the structural unit (I) is a monomer represented by the following formula (3).

In the above formula (3), R ¹ , R ² , R ³ and R ^H have the same meanings as R ¹ , R ² , R ³ and R ^H in the above formula (1), respectively.

When R ^H in the above formula (3) is a monovalent group obtained by removing one hydroxyl group from a cyclodextrin derivative, the monomer represented by the above formula (3) can be synthesized, for example, by the following method (i) or (ii).
(i) A method of dehydrating and condensing a compound represented by the following formula (4) with cyclodextrin, and substituting the hydrogen atoms of the hydroxyl groups in the resulting condensate with substituents. (ii) A method of substituting the hydrogen atoms of the hydroxyl groups in cyclodextrin with substituents, and dehydrating and condensing the compound represented by the following formula (4) with the resulting cyclodextrin derivative.

In the above formula (4), ^R1 and ^R2 are the same as ^R1 and ^R2 in the above formula (1), respectively. ^R5 is a group represented by -OH or ^-NHR4 ( ^R4 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms).

In the above method (i), dehydration condensation occurs between the group R ⁵ (—OH or —NHR ⁴ ) of the compound represented by formula (4) and the hydroxyl group of cyclodextrin. This dehydration condensation can be carried out in a solvent, if necessary, in the presence of an acid catalyst.

The acid catalyst is not particularly limited, and a wide variety of known catalysts can be used, such as p-toluenesulfonic acid, aluminum chloride, hydrochloric acid, etc. The amount of the acid catalyst used can be, for example, 0.01 mol % or more and 20 mol % or less relative to the cyclodextrin.

The solvent used in the above dehydration condensation reaction is not particularly limited, and examples thereof include dimethylformamide, dimethylsulfoxide, and N-methylpyrrolidone. The reaction temperature and reaction time of the dehydration condensation are also not limited, and the reaction can be carried out under appropriate conditions. From the viewpoint of proceeding with the reaction more quickly, the reaction temperature is preferably 25 to 100°C, and the reaction time is preferably 1 minute to 3 hours.

A known method can be used to replace the hydrogen atom of the hydroxyl group in the obtained condensation product with a substituent.

The hydrogen atoms of the hydroxyl groups present in the condensate (cyclodextrin) can be replaced with hydrocarbon groups as substituents by, for example, any of the well-known alkylation reactions. For example, the replacement with a hydrocarbon group can be carried out by reacting an alkyl halide with the condensate in the presence of sodium hydride. Examples of alkyl halides include methyl iodide, ethyl iodide, and propyl iodide.

The hydrogen atom of the hydroxyl group present in the condensate (cyclodextrin) can be replaced with an acyl group such as an acetyl group by, for example, any of the known acylation reactions. For example, the replacement with an acetyl group can be carried out by reacting an acetyl halide with the condensate in the presence of sodium hydride. Examples of acetyl halides include acetyl bromide and acetyl iodide.

The hydrogen atom of the hydroxyl group present in the condensate (cyclodextrin) can be replaced with -CONHR (R is a methyl group or an ethyl group) by, for example, a widely known alkyl carbamate reaction. Examples of alkyl carbamate agents used in alkyl carbamate reactions include alkyl isocyanates such as methyl isocyanate and ethyl isocyanate.

The method of substituting the hydrogen atom of the hydroxyl group in the cyclodextrin with a substituent in the above method (ii) can be carried out by known alkylation reactions, acylation reactions, alkyl carbamate reactions, etc., similar to the respective substitution reactions in the above method (i). In addition, the dehydration condensation in the above method (ii) can also be carried out by known methods, such as the dehydration condensation in the above method (i).

In addition, monomer (I) can be synthesized in accordance with the methods described in WO2018/159791 and WO2017/159346.

[A] The lower limit of the content of the structural unit (I) in the polymer is preferably 1% by mass, more preferably 2% by mass, even more preferably 3% by mass, and even more preferably 5% by mass. On the other hand, the upper limit of the content of the structural unit (I) is preferably 80% by mass, more preferably 50% by mass, even more preferably 30% by mass, and even more preferably 20% by mass. By making the content of the structural unit (I) equal to or higher than the above lower limit, the performance of the radiation-sensitive composition based on the structural unit (I) is further improved. On the other hand, by making the content of the structural unit (I) equal to or lower than the above upper limit, other structural units can be contained in sufficient amounts, and other performances such as developability can be sufficiently improved.

(Structural Unit (II))
The polymer [A] preferably further contains a structural unit (II) having a carboxy group or a phenolic hydroxyl group. The polymer [A] contains the structural unit (II), which can improve the coatability, developability, pattern shape of the obtained cured film, etc. As the structural unit (II), a structural unit having a carboxy group is more preferable.

Examples of monomers which provide the structural unit (II) include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and 4-vinylbenzoic acid;
Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid;
Anhydrides of the above unsaturated dicarboxylic acids;
Examples of the monomer include (meth)acrylic acid esters having a phenolic hydroxyl group such as 4-hydroxyphenyl (meth)acrylate, etc. These monomers can be used alone or in combination of two or more.

[A] The lower limit of the content of structural unit (II) in the polymer is preferably 1% by mass, more preferably 3% by mass, and even more preferably 5% by mass. On the other hand, the upper limit of the content of structural unit (II) is preferably 50% by mass, more preferably 40% by mass, and even more preferably 30% by mass.

(Structural unit (III))
The polymer [A] preferably contains a structural unit (III) having a monovalent hydrocarbon group having 1 to 20 carbon atoms. When the polymer [A] contains the structural unit (III), the solubility of the polymer [A] is optimized, and thus the properties such as LWR become more excellent.

Examples of monovalent hydrocarbon groups having 1 to 20 carbon atoms include aliphatic hydrocarbon groups having 1 to 20 carbon atoms and aromatic hydrocarbon groups having 6 to 20 carbon atoms.

As the aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aliphatic chain hydrocarbon group is preferable, and specific examples include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, nonyl, decyl, dodecyl, pentadecyl, and octadecyl groups, alkenyl groups such as ethenyl, propenyl, butenyl, hexenyl, octenyl, decenyl, and octadecenyl groups, and alkynyl groups such as ethynyl, propynyl, butynyl, hexynyl, octynyl, decynyl, and octadecenyl groups.

Examples of aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenyl groups, benzyl groups, tolyl groups, xylyl groups, naphthyl groups, and anthracenyl groups.

The lower limit of the number of carbon atoms in this monovalent hydrocarbon group is preferably 2, more preferably 3, and even more preferably 4. On the other hand, the upper limit of the number of carbon atoms is preferably 15, and more preferably 10.

Examples of monomers that give structural unit (III) include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, benzyl (meth)acrylate, naphthyl (meth)acrylate, styrene, and phenyl vinyl ether. The monomer that gives structural unit (III) is preferably a (meth)acrylic acid ester. These monomers can be used alone or in combination.

[A] The lower limit of the content of structural unit (III) in the polymer is preferably 10% by mass, more preferably 30% by mass, even more preferably 50% by mass, and even more preferably 70% by mass. On the other hand, the upper limit of the content of structural unit (III) is preferably 95% by mass, more preferably 90% by mass, even more preferably 85% by mass, and even more preferably 80% by mass.

(Structural Unit (IV))
The polymer (A) may further contain a structural unit (IV) other than the structural units (I) to (III).

Examples of monomers that provide structural unit (IV) include 2-hydroxyethyl (meth)acrylate, polyethylene glycol methyl ether (meth)acrylate, polypropylene glycol methyl ether (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, etc. These monomers can be used alone or in combination of two or more.

[A] The upper limit of the content of structural unit (IV) in the polymer is preferably 30% by mass, more preferably 10% by mass, even more preferably 3% by mass, and particularly preferably 1% by mass.

It is preferable that the [A] polymer does not substantially contain a structural unit (V) having an alicyclic hydrocarbon group having 6 to 30 carbon atoms. An alicyclic hydrocarbon group having 6 to 30 carbon atoms is easily included in a host group, which is a monovalent group obtained by removing one hydrogen atom or hydroxyl group from a cyclodextrin derivative. For this reason, when the [A] polymer does not substantially contain such a structural unit (V), the occurrence of host-guest interactions between the [A] polymers is suppressed, and host-guest interactions between the [A] polymer and the [G1] guest compound or the [G2] guest compound are likely to occur. The upper limit of the content ratio of the structural unit (V) in the [A] polymer is preferably 10% by mass, more preferably 3% by mass, even more preferably 1% by mass, even more preferably 0.1% by mass, and particularly preferably 0% by mass. However, depending on the structure of the host group possessed by the [A] polymer, an [A] polymer containing a structural unit (V) having an alicyclic hydrocarbon group having 6 to 30 carbon atoms can also be preferably used.

[A] The polymer can be obtained, for example, by polymerizing each of the above monomers by a known method such as radical polymerization.

[A] The weight average molecular weight (Mw) of the polymer is usually 1,000 to 100,000, preferably 3,000 to 30,000. Mw refers to the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography.

The lower limit of the content of the polymer [A] in the solid content of the radiation-sensitive composition is preferably 10% by mass, more preferably 30% by mass, and even more preferably 50% by mass. On the other hand, the upper limit of this content is preferably 90% by mass, more preferably 80% by mass, more preferably 70% by mass, and even more preferably 60% by mass or 50% by mass. By setting the content of the polymer [A] in the above range, the content ratio with other components is optimized, and the characteristics required for the pattern forming material are further improved. The solid content refers to all components other than the solvent.

<[G1-1] Crosslinkable compound>
The radiation-sensitive composition containing the crosslinkable compound [G1-1] is particularly excellent in the properties required for a pattern-forming material, such as sensitivity, exposure latitude, depth of focus, LWR, film loss, and heat resistance. The crosslinkable compound [G1-1] preferably has one or more guest groups and one or more crosslinkable groups. In one embodiment, the crosslinkable compound [G1-1] may be a compound having one guest group and one crosslinkable group.

The guest group is not particularly limited as long as it is a group that can be included in the host group of the polymer [A], but a hydrocarbon group having 6 to 30 carbon atoms is preferred.

The hydrocarbon group having 6 to 30 carbon atoms is usually a monovalent group. Examples of the hydrocarbon group having 6 to 30 carbon atoms include a chain hydrocarbon group having 6 to 30 carbon atoms, an alicyclic hydrocarbon group having 6 to 30 carbon atoms, and an aromatic hydrocarbon group having 6 to 30 carbon atoms.
Examples of the chain hydrocarbon group having 6 to 30 carbon atoms include alkyl groups such as a hexyl group, octyl group, nonyl group, decyl group, dodecyl group, pentadecyl group, and octadecyl group; alkenyl groups such as a hexenyl group, octenyl group, decenyl group, and octadecenyl group; and alkynyl groups such as a hexynyl group, octynyl group, decynyl group, and octadecynyl group.
Examples of the alicyclic hydrocarbon group having 6 to 30 carbon atoms include monovalent monocyclic alicyclic saturated hydrocarbon groups such as a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; monovalent monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclohexenyl group, a cyclooctenyl group, and a cyclodecenyl group; monovalent polycyclic alicyclic saturated hydrocarbon groups such as a norbornyl group, an isobornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group; and monovalent polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group, a tricyclodecenyl group, and a tetracyclododecenyl group.
Examples of the aromatic hydrocarbon group having 6 to 30 carbon atoms include a phenyl group, a benzyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthracenyl group.

Among the hydrocarbon groups having 6 to 30 carbon atoms, alicyclic hydrocarbon groups having 6 to 30 carbon atoms and aromatic hydrocarbon groups having 6 to 30 carbon atoms are preferred, and alicyclic hydrocarbon groups having 6 to 30 carbon atoms are more preferred. Such hydrocarbon groups can be effectively encapsulated in groups derived from cyclodextrin derivatives. As the alicyclic hydrocarbon group, a polycyclic group is preferred, and a polycyclic alicyclic saturated hydrocarbon group is more preferred. The lower limit of the number of carbon atoms in the hydrocarbon group is preferably 8. On the other hand, the upper limit is preferably 20, and more preferably 15.

A crosslinkable group is a group that can form a crosslinked structure by chemical reaction. Examples of crosslinkable groups include epoxy groups, cyclic carbonate groups, methylol groups (hydroxymethyl structure), (meth)acryloyl groups, and vinyl groups. Note that an epoxy group refers to a cyclic ether group, and examples of such groups include an oxiranyl group (1,2-epoxy structure) and an oxetanyl group (1,3-epoxy structure). As crosslinkable groups, (meth)acryloyl groups and vinyl groups are preferred, and (meth)acryloyl groups are more preferred.

[G1-1] Examples of crosslinkable compounds include cyclohexyl (meth)acrylate, cyclooctyl (meth)acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, ethyl adamantyl (meth)acrylate, cyclohexyl adamantyl (meth)acrylate, N-cyclohexyl (meth)acrylamide, N-cyclooctyl (meth)acrylamide, N-norbornyl (meth)acrylamide, N-isobornyl (meth)acrylamide, N- Examples of the vinyl ether include adamantyl (meth)acrylamide, cyclohexyl vinyl ether, cyclooctyl vinyl ether, norbornyl vinyl ether, isobornyl vinyl ether, adamantyl vinyl ether, cyclohexyl allyl ether, cyclooctyl allyl ether, norbornyl vinyl ether, isobornyl vinyl ether, adamantyl vinyl ether, hexyl (meth)acrylate, decyl (meth)acrylate, benzyl (meth)acrylate, naphthyl (meth)acrylate, and styrene.

In the radiation-sensitive composition, at least a portion of the crosslinkable compound [G1-1] is usually present in a state in which the guest group is included in the host group of the polymer [A]. In other words, the polymer [A] and at least a portion of the crosslinkable compound [G1-1] form an inclusion compound.

The weight average molecular weight (Mw) of the inclusion compound (polymer) formed from the polymer [A] and the crosslinkable compound [G1-1] is typically 1,000 to 100,000, preferably 3,000 to 30,000.

The lower limit of the content of the crosslinkable compound [G1-1] is preferably 1 part by mass, more preferably 10 parts by mass, and even more preferably 20 parts by mass, per 100 parts by mass of the polymer [A]. On the other hand, the upper limit of this content is preferably 200 parts by mass, more preferably 100 parts by mass, and even more preferably 60 parts by mass. By having the content of the crosslinkable compound [G1-1] within the above range, the properties required of a pattern forming material are further improved, such as the crosslinked structure being able to be particularly satisfactorily formed by chemical reaction.

<[G1-2] Photoreactive compound>
The photoreactive compound [G1-2] is a compound whose structure changes upon reaction with light or other radiation. Examples of photoreactions caused by the photoreactive compound [G1-2] include isomerization reactions, bimolecular cyclization reactions, ring-closing reactions, ring-opening reactions, addition reactions, elimination reactions, condensation reactions, solvolysis reactions, nucleophilic reactions, electrophilic reactions, radical reactions, and complexation reactions. Among these, isomerization reactions, bimolecular cyclization reactions, ring-closing reactions, and ring-opening reactions are preferred, and isomerization reactions are more preferred.

Compounds that undergo isomerization reactions include azobenzene compounds and stilbene compounds. Compounds that undergo bimolecular cyclization reactions include cinnamic acid compounds, coumarin compounds, and chalcone compounds. Compounds that undergo ring-closing reactions include diarylethene compounds, fulgide compounds, and fulgimide compounds. Compounds that undergo ring-opening reactions include spiropyran compounds and spirooxazine compounds.

[G1-2] The photoreactive compound may be a low molecular weight compound or a high molecular weight compound, but in the case of a high molecular weight compound, it is preferable that the compound is a high molecular weight compound having a pendant photoreactive moiety.

[G1-2] As the photoreactive compound, a photoisomerizable compound is preferred, and an azobenzene-based compound and a stilbene-based compound are more preferred. The azobenzene-based compound refers to azobenzene and a compound in which at least one hydrogen atom of the azobenzene is substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. The stilbene-based compound refers to stilbene and a compound in which at least one hydrogen atom of the stilbene is substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. In other words, the photoisomerizable compound as the photoreactive compound [G1-2] is preferably azobenzene, stilbene, or a compound in which at least one hydrogen atom of these is substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. In such photoisomerizable compounds, when they are in the trans form, they are easily included in the cyclodextrin derivative, while when they are photoisomerized to become a cis form, they are easily released from the cyclodextrin derivative. For this reason, when such a photoreactive compound [G1-2] is used in combination with a polymer [A] having, as a host group, a monovalent group obtained by removing one hydrogen atom or hydroxyl group from a cyclodextrin derivative, and a guest compound [G2] as a polymer having a guest group, the formation of a crosslinked structure due to the host-guest interaction upon irradiation with light as described above occurs particularly effectively.

Specific examples of monovalent hydrocarbon groups having 1 to 12 carbon atoms are as described above, with linear hydrocarbon groups being preferred, and linear hydrocarbon groups having 1 to 4 carbon atoms being more preferred.

An alkoxy group having 1 to 12 carbon atoms refers to a group in which a monovalent hydrocarbon group having 1 to 12 carbon atoms is bonded to an oxygen atom (-O-). Among alkoxy groups having 1 to 12 carbon atoms, groups in which a chain hydrocarbon group is bonded to an oxygen atom are preferred, and groups in which a chain hydrocarbon group having 1 to 4 carbon atoms is bonded to an oxygen atom, such as a methoxy group or an ethoxy group, are more preferred.

In the radiation-sensitive composition, at least a portion of the photoreactive compound [G1-2] is usually present in a state where the whole molecule or a portion of the molecule is included in the host group of the polymer [A]. In other words, the polymer [A] and at least a portion of the photoreactive compound [G1-2] form an inclusion compound. In addition, when the photoreactive compound [G1-2] is a cis-trans isomer, it is usually included in the host group of the polymer [A] in the trans form.

The weight average molecular weight (Mw) of the inclusion compound (polymer) formed from the polymer [A] and the photoreactive compound [G1-2] is typically 1,000 to 100,000, preferably 3,000 to 30,000.

The lower limit of the content of the photoreactive compound [G1-2] is preferably 50 mol %, and more preferably 100 mol %, relative to the content of the host group in the polymer [A]. On the other hand, the upper limit of this content is preferably 200 mol %, and more preferably 150 mol %. By having the content of the photoreactive compound [G1-2] within the above range, the properties required of the pattern forming material are further improved.

The lower limit of the content of the inclusion compound (polymer) formed from the polymer [A] and the photoreactive compound [G1-2] in the solid content of the radiation-sensitive composition is preferably 10% by mass, more preferably 30% by mass, and even more preferably 40% by mass. On the other hand, the upper limit of this content is preferably 90% by mass, more preferably 70% by mass, and even more preferably 60% by mass. By having the content of the inclusion compound in the above range, the properties required of the pattern forming material are further improved.

<[G2] Guest compound>
When the [G1] guest compound is a [G1-2] photoreactive compound, the radiation-sensitive composition preferably further contains a [G2] guest compound. The [G2] guest compound is a compound having a guest group other than the [G1-2] photoreactive compound. In a radiation-sensitive composition containing a [G1-2] photoreactive compound and a [G2] guest compound, usually at least a part of the [G1-2] photoreactive compound is included in the host group of the [A] polymer. On the other hand, the [G2] guest compound is usually not included in the host group of the [A] polymer and exists in a free state. By exposing a coating film of such a radiation-sensitive composition, at least a part of the [G1-2] photoreactive compound is released from the host group, and in its place, at least a part of the [G2] guest compound is included in the host group. As a result, the [A] polymer and the [G2] guest compound are bonded by host-guest interaction, and when the [G2] guest compound is a polymer having a guest group (a [G2] polymer), a crosslinked structure is formed between the [A] polymer and the [G2] guest compound (a [G2] polymer) by the host-guest interaction.

The guest group of the [G2] guest compound is not particularly limited as long as it can be included in the host group of the [A] polymer, but is preferably a hydrocarbon group having 6 to 30 carbon atoms, more preferably an alicyclic hydrocarbon group having 6 to 30 carbon atoms and an aromatic hydrocarbon group having 6 to 30 carbon atoms, and even more preferably an alicyclic hydrocarbon group having 6 to 30 carbon atoms. When the [G1-2] photoreactive compound is released from the host group, such a hydrocarbon group can be effectively included in the host group, particularly a group derived from a cyclodextrin derivative. For this reason, when a [G2] guest compound having such a hydrocarbon group is used, the properties required for a pattern forming material, such as sensitivity, exposure margin, depth of focus, LWR, film loss, and heat resistance, become particularly good.

<Polymer [G2]>
The guest compound (G2) is preferably a polymer containing a structural unit (i) having a guest group (hereinafter also referred to as the polymer (G2)).

(Structural unit (i))
The guest group in the structural unit (i) is preferably a hydrocarbon group having 6 to 30 carbon atoms. Specific examples and suitable examples of the hydrocarbon group having 6 to 30 carbon atoms as the guest group in the structural unit (i) are the same as those explained in the crosslinkable compound [G1-1]. That is, the lower limit of the number of carbon atoms in the hydrocarbon group is preferably 8. On the other hand, the upper limit is preferably 20, more preferably 15. Among the hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups are preferred, and alicyclic hydrocarbon groups are more preferred. As the alicyclic hydrocarbon group, a polycyclic group such as a norbornyl group, an isobornyl group, or an adamantyl group is preferred, and a polycyclic alicyclic saturated hydrocarbon group is more preferred. The structural unit (i) may also include a structural unit having an alicyclic hydrocarbon group having 6 to 30 carbon atoms and a structural unit having an aromatic hydrocarbon group having 6 to 30 carbon atoms.

Monomers that give structural unit (i) include cyclohexyl (meth)acrylate, cyclooctyl (meth)acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, ethyl adamantyl (meth)acrylate, cyclohexyl adamantyl (meth)acrylate, N-cyclohexyl (meth)acrylamide, N-cyclooctyl (meth)acrylamide, N-norbornyl (meth)acrylamide, N-isobornyl (meth)acrylamide, N Adamantyl (meth)acrylamide, cyclohexyl vinyl ether, cyclooctyl vinyl ether, norbornyl vinyl ether, isobornyl vinyl ether, adamantyl vinyl ether, cyclohexyl allyl ether, cyclooctyl allyl ether, norbornyl vinyl ether, isobornyl vinyl ether, adamantyl vinyl ether, styrene, benzyl (meth)acrylate, naphthyl (meth)acrylate, hexyl (meth)acrylate, decyl (meth)acrylate, and the like.

[G2] The lower limit of the content of structural unit (i) in the polymer is preferably 10% by mass, more preferably 20% by mass, and even more preferably 30% by mass. On the other hand, the upper limit of the content of structural unit (i) is preferably 95% by mass, more preferably 90% by mass, even more preferably 80% by mass, and in some cases even more preferably 70% by mass or 60% by mass. By setting the content of structural unit (i) within the above range, it is possible to form a sufficient crosslinked structure due to host-guest interaction. In addition, from the viewpoint of being able to form a crosslinked structure due to host-guest interaction more sufficiently, the content of structural units having an alicyclic hydrocarbon group having 6 to 30 carbon atoms in structural unit (i) is preferably 50% by mass or more, and more preferably 60% by mass or more.

(Structural unit (ii))
It is preferable that the polymer [G2] further contains a structural unit (ii) having a crosslinkable group. The crosslinkable group of the structural unit (ii) is a group capable of forming a crosslinked structure by chemical reaction. By further containing the structural unit (ii) of the polymer [G2], a crosslinked structure by chemical reaction can be formed in addition to the crosslinked structure by host-guest interaction, and the curability and heat resistance of the resulting pattern (cured film) are improved. Examples of the crosslinkable group of the structural unit (ii) include the same ones as those exemplified as the crosslinkable group of the crosslinkable compound [G1-1], but (meth)acryloyl group and epoxy group are preferred.

A structural unit having a (meth)acryloyl group can be formed, for example, by reacting a carboxy group in a polymer containing a structural unit having a carboxy group with a (meth)acrylic acid ester having an epoxy group.

The monomer that gives the structural unit having a carboxy group is the same as the example of the monomer that gives the structural unit (II) of the polymer [A], and among them, acrylic acid, methacrylic acid and maleic anhydride are preferred. These monomers can be used alone or in combination of two or more.

Examples of (meth)acrylic acid esters having an epoxy group include glycidyl (meth)acrylate, 3-(meth)acryloyloxymethyl-3-ethyloxetane, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxytricyclo[5.2.1.0 ^2.6 ]decyl (meth)acrylate, and tris(4-hydroxyphenyl)ethane triglycidyl ether.

The structural unit having a (meth)acryloyl group obtained by reacting a (meth)acrylic acid ester having an epoxy group with the carboxy group of a structural unit having a carboxy group may be represented by the following formula (5).

In formula (5), R ³⁰ and R ³¹ are each independently a hydrogen atom or a methyl group, a is an integer of 1 to 6, and R ³² is a divalent group represented by the following formula (5-1) or formula (5-2).

In formula (5-1), R ³³ is a hydrogen atom or a methyl group. In formulas (5-1) and (5-2), * indicates the site of bonding to an oxygen atom.

Regarding the structural unit represented by formula (5), for example, when a polymer containing a structural unit having a carboxy group is reacted with a compound such as glycidyl methacrylate or 2-methylglycidyl methacrylate, R ³² in formula (5) becomes a group represented by formula (5-1). On the other hand, when a compound such as 3,4-epoxycyclohexylmethyl methacrylate is reacted, R ³² in formula (5) becomes a group represented by formula (5-2).

In addition, structural units having a (meth)acryloyl group can be formed by a method of reacting (meth)acrylic acid with an epoxy group in a polymer containing a structural unit having an epoxy group, or by a method of reacting a (meth)acrylic acid ester having an isocyanate group with a hydroxyl group in a polymer containing a structural unit having a hydroxyl group.

Examples of monomers that provide structural units having epoxy groups include unsaturated compounds containing oxiranyl groups (1,2-epoxy structure), oxetanyl groups (1,3-epoxy structure), etc.

Examples of unsaturated compounds having an oxiranyl group include glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, α-ethyl-6,7-epoxyheptyl acrylate, 3,4-epoxycyclohexyl methacrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether.

Examples of unsaturated compounds having an oxetanyl group include 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 3-(2-methacryloyloxyethyl)oxetane, 3-(2-methacryloyloxyethyl)-2-ethyloxetane, 3-(2-methacryloyloxyethyl)-3-ethyloxetane, 3-(2-methacryloyloxyethyl)-2-phenyloxetane, and 3-(2-methacryloyloxyethyl)-2,2-difluorooxetane.

[G2] The lower limit of the content of structural unit (ii) in the polymer is preferably 5% by mass, more preferably 20% by mass. On the other hand, the upper limit of the content of structural unit (ii) is preferably 60% by mass, more preferably 50% by mass.

(Structural unit (iii))
The polymer [G2] preferably contains a structural unit having a monovalent hydrocarbon group having 1 to 5 carbon atoms. When the polymer [G2] contains the structural unit (iii), the solubility of the polymer [G2] is optimized, and thus the properties such as LWR become more excellent.

Examples of monomers that provide structural unit (iii) include those that have a monovalent hydrocarbon group having 1 to 5 carbon atoms among the monomers that provide structural unit (III) of the polymer [A] described above. Among such monomers, (meth)acrylic acid esters such as methyl (meth)acrylate and ethyl (meth)acrylate are preferred.

[G2] The lower limit of the content of structural unit (iii) in the polymer is preferably 5% by mass, more preferably 10% by mass. On the other hand, the upper limit of the content of structural unit (iii) is preferably 60% by mass, more preferably 40% by mass.

(Structural unit (iv))
The polymer [G2] preferably further contains a structural unit (iv) having a carboxy group or a phenolic hydroxyl group. The polymer [G2] contains the structural unit (iv), and thus the coating property, developability, and pattern shape of the obtained cured film can be improved. The structural unit (iv) is more preferably a structural unit having a carboxy group. Examples of the monomer that gives the structural unit (iv) include the same monomers that give the structural unit (II) described above.

[G2] The lower limit of the content of structural unit (iv) in the polymer is preferably 5% by mass, more preferably 10% by mass. On the other hand, the upper limit of the content of structural unit (iv) is preferably 40% by mass, more preferably 30% by mass.

(Structural Unit (v))
The polymer [G2] may further contain a structural unit (v) other than the structural units (i) to (iv). Examples of the monomer that provides the structural unit (v) include the same monomers as those that provide the structural unit (IV) described above.

[G2] The upper limit of the content of structural unit (v) in the polymer is preferably 30% by mass, more preferably 10% by mass, even more preferably 3% by mass, and even more preferably 1% by mass.

[G2] The polymer can be obtained, for example, by polymerizing each of the above monomers by a known method such as radical polymerization.

[G2] The weight average molecular weight (Mw) of the polymer is typically 1,000 to 100,000, preferably 3,000 to 50,000.

The lower limit of the content of the [G2] guest compound ([G2] polymer) in the radiation-sensitive composition is preferably 40 parts by mass, and more preferably 60 parts by mass, per 100 parts by mass of the total of the [A] polymer and the [G1-2] photoreactive compound. On the other hand, the upper limit of this content is preferably 200 parts by mass, and more preferably 150 parts by mass. By having the content of the [G2] guest compound ([G2] polymer) within the above range, the properties required of a pattern-forming material are further improved.

<[B] Polymerizable compound>
It is preferable that the radiation-sensitive composition further contains another polymerizable compound (polymerizable compound [B]) other than the crosslinkable compound [G1-1] and the polymer [G2] containing the structural unit (ii). The polymerizable compound [B] further improves various properties such as sensitivity, film loss, and heat resistance. The polymerizable compound [B] is a compound having a crosslinkable group (polymerizable group) as described above. The polymerizable compound [B] may be used alone or in combination of two or more kinds.

[B] As the polymerizable compound, a polymerizable compound having an ethylenically unsaturated bond is preferably used. [B] As the polymerizable compound, for example, monofunctional (meth)acrylate compounds such as ω-carboxypolycaprolactone mono(meth)acrylate and 2-(2'-vinyloxyethoxy)ethyl (meth)acrylate; ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, bisphenoxyethanol fluorene di(meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol acrylate, tetramethylolpropane tri(meth) ... Examples of the polyfunctional (meth)acrylate compounds include urethane (meth)acrylate compounds obtained by reacting a compound having a linear alkylene group and an alicyclic structure and having two or more isocyanate groups with a compound having one or more hydroxyl groups in the molecule and having 3 to 5 (meth)acryloyloxy groups; and vinyl compounds such as 1,2-divinylcyclobutane and divinylbenzene.

The lower limit of the content of the polymerizable compound [B] in the solid content of the radiation-sensitive composition is preferably 0.1% by mass, more preferably 5% by mass. Meanwhile, the upper limit of this content is preferably 50% by mass, more preferably 30% by mass. Also, the lower limit of the content of the polymerizable compound [B] is preferably 1 part by mass, more preferably 5 parts by mass, relative to 100 parts by mass of the polymer [A]. Meanwhile, the upper limit of this content is preferably 100 parts by mass, more preferably 50 parts by mass.

<[C] Radiation-sensitive polymerization initiator>
The radiation-sensitive composition may preferably contain a radiation-sensitive polymerization initiator [C]. The radiation-sensitive polymerization initiator [C] is a component that generates an active species capable of initiating polymerization (crosslinking reaction) of a component having a crosslinkable group in response to radiation. Examples of the component having a crosslinkable group include a crosslinkable compound [G1-1], a polymer [G2] containing a structural unit (ii), and a polymerizable compound [B].

[C] Examples of the radiation-sensitive polymerization initiator include radical polymerization initiators. [C] Examples of the radiation-sensitive polymerization initiator include oxime ester compounds, acetophenone compounds, biimidazole compounds, etc. [C] The radiation-sensitive polymerization initiators may be used alone or in combination of two or more.

Examples of oxime ester compounds include ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)], 1-[9-ethyl-6-benzoyl-9H-carbazol-3-yl]-octan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9H-carbazol-3-yl]-ethane-1-one oxime-O-benzoate, ethanone-1-[9-ethyl and O-acyloxime compounds such as ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), and ethanone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl}-9H-carbazol-3-yl]-1-(O-acetyloxime).

Examples of acetophenone compounds include α-aminoketone compounds, α-hydroxyketone compounds, etc.

Examples of α-aminoketone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one.

Examples of α-hydroxyketone compounds include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, etc.

Examples of biimidazole compounds include 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, and 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole.

When the radiation-sensitive composition contains a component having an epoxy group or the like as a crosslinkable group, a radiation-sensitive acid generator can also be used as the radiation-sensitive polymerization initiator [C]. Examples of radiation-sensitive acid generators include sulfonimide compounds and tetrahydrothiophenium salts.

Examples of sulfonimide compounds include N-(trifluoromethylsulfonyloxy)-1,8-naphthalene dicarboimide, N-(camphorsulfonyloxy)naphthyldicarboxylimide, etc.

Examples of tetrahydrothiophenium salts include 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium trifluoromethanesulfonate and 1-(4,7-dibutoxy-1-naphthalenyl)tetrahydrothiophenium trifluoromethanesulfonate.

Other examples of radiation-sensitive acid generators include onium salts, oxime sulfonate compounds, thianthrene compounds, etc. Commercially available products can be used as these radiation-sensitive acid generators.

The lower limit of the content of the radiation-sensitive polymerization initiator [C] in the solid content of the radiation-sensitive composition is preferably 0.1% by mass, more preferably 1% by mass. On the other hand, the upper limit of this content is preferably 20% by mass, more preferably 10% by mass. In addition, the lower limit of the content of the radiation-sensitive polymerization initiator [C] is preferably 1 part by mass, more preferably 3 parts by mass, per 100 parts by mass of the component having a crosslinkable group. On the other hand, the upper limit of this content is preferably 50 parts by mass, more preferably 30 parts by mass.

<Other ingredients>
The radiation-sensitive composition may contain, as necessary, an antioxidant, a surfactant, an adhesion aid, a solvent, and the like.

Examples of the antioxidant include hindered phenol-based, hindered amine-based, phosphorus-based, thiol-based, benzotriazole-based, benzophenone-based, hydroxylamine-based, salicylic acid ester-based, and triazine-based compounds. Known antioxidants can be used as the antioxidant. The content of the antioxidant in the solid content of the radiation-sensitive composition can be, for example, 0.01% by mass or more and 5% by mass or less.

Examples of the surfactant include a fluorine-based surfactant and a silicone-based surfactant. The content of the surfactant in the solid content of the radiation-sensitive composition can be, for example, 0.001% by mass or more and 1% by mass or less.

As the adhesion aid, a silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, or an oxiranyl group is preferably used, and examples thereof include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The content of the adhesion aid in the solid content of the radiation-sensitive composition can be, for example, 0.01% by mass or more and 5% by mass or less.

Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and octanol;
Esters such as ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate;
Ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene diglycol monomethyl ether, and ethylene diglycol ethyl methyl ether;
Amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone can be used.

Solvents can be used alone or in a mixture of two or more.

The solids concentration of the radiation-sensitive composition is, for example, 10% by mass or more and 80% by mass or less.

<Method of Preparing Radiation-Sensitive Composition>
The radiation-sensitive composition can be prepared by mixing the polymer [A], the guest compound [G1], and other components as necessary in a predetermined ratio, and dissolving or dispersing the mixture in a suitable solvent. The prepared radiation-sensitive composition is preferably filtered through a filter having a pore size of about 0.2 μm.

When the radiation-sensitive composition uses a combination of a [G1] guest compound and a [G2] guest compound, it is preferable to prepare the radiation-sensitive composition in the following manner. First, the [A] polymer and the [G1] guest compound are mixed to obtain an inclusion compound of the [A] polymer and the [G1] guest compound. This inclusion compound is mixed with the [G2] guest compound and, if necessary, other components to obtain a radiation-sensitive composition. By preparing the radiation-sensitive composition in this manner, a radiation-sensitive composition can be obtained in which the [G1] guest compound is included in the host group of the [A] polymer and the [G2] guest compound is not included.

When the [G2] guest compound is not used, the [A] polymer and the [G1] guest compound may be mixed in advance to obtain an inclusion compound, which is then mixed with other components, or the [A] polymer and the [G1] guest compound may be mixed with other components at the same time. In either case, a radiation-sensitive composition can be obtained in which the [G1] guest compound is encapsulated in the host group of the [A] polymer.

<Inclusion compounds>
The inclusion compound according to one embodiment of the present invention comprises
An inclusion compound in which at least a part of a first guest compound (guest compound [G1]) is included in a host group of a polymer (polymer [A]) having a host group,
the host group is a monovalent group obtained by removing one hydrogen atom or one hydroxyl group from a cyclodextrin derivative,
The cyclodextrin derivative has a structure in which a hydrogen atom of at least one hydroxyl group of cyclodextrin is substituted with at least one group selected from the group consisting of a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, and -CONHR, wherein R is a methyl group or an ethyl group;
The first guest compound (guest compound [G1]) is an inclusion compound having a crosslinkable group and a hydrocarbon group having 6 to 30 carbon atoms.

The inclusion compound is the one described above as the inclusion compound formed from the polymer [A] and the crosslinkable compound [G1-1] in the radiation-sensitive composition according to one embodiment of the present invention. Therefore, the specific and preferred aspects of the inclusion compound are the same as those described above.

<Pattern Formation Method>
A pattern forming method according to one embodiment of the present invention includes the steps of:
(1) forming a coating film on a substrate using a radiation-sensitive composition according to one embodiment of the present invention;
(2) a step of exposing the coating film to light; and (3) a step of developing the coating film after exposure.

[Step (1)]
In step (1), the radiation-sensitive composition is applied onto a substrate, and prebaked as necessary to form a coating film. Examples of the substrate used in step (1) include glass substrates, silicon wafers, plastic substrates, and substrates having various inorganic films such as silicon nitride formed on their surfaces. Examples of the plastic substrate include substrates mainly made of plastics such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethersulfone, polycarbonate, and polyimide. The substrate may be provided with an underlayer film such as an anti-reflection film.

The radiation-sensitive composition can be applied by any suitable method, such as spraying, roll coating, rotary coating (spin coating), slit die coating, bar coating, or inkjet coating.

The pre-baking conditions vary depending on the type and amount of components contained in the radiation-sensitive composition, but can be, for example, at 60°C or higher and 100°C or lower for 20 seconds or higher and 10 minutes or lower.

The average thickness of the coating film after prebaking is preferably 0.1 μm, more preferably 0.5 μm, and more preferably 15 μm, more preferably 10 μm, and even more preferably 5 μm.

[Step (2)]
In step (2), for example, the coating film formed in step (1) is irradiated with radiation through a mask having a predetermined pattern. Examples of the radiation include ultraviolet light, far ultraviolet light, X-rays, and charged particle beams.

In particular, when a radiation-sensitive composition containing an azobenzene-based compound or a stilbene-based compound as the [G1-2] photoreactive compound is used, radiation having at least one of the wavelengths of 246 nm and 365 nm is preferred. Azobenzene-based compounds are isomerized from trans to cis at a wavelength of 365 nm (such as i-line). Stilbene-based compounds are isomerized from trans to cis at a wavelength of 246 nm (such as KrF excimer laser light). Therefore, when a radiation-sensitive composition contains an [A] polymer, an azobenzene-based compound or a stilbene-based compound as the [G1-2] photoreactive compound, and a [G2] polymer as the [G2] guest compound, exposure to radiation of such a wavelength causes the [G1-2] reactive compound to be released from the host group of the [A] polymer, and the guest group of the [G2] polymer to be included in the host group of the [A] polymer, effectively forming a crosslinked structure between the [A] polymer and the [G2] polymer.

In addition, in the case of radiation-sensitive compositions of other compositions, the radiation is not particularly limited, and radiation of other wavelengths can also be used.

The radiation exposure amount is, for example, preferably from 10 J/m ² to 100,000 J/m ² , and more preferably 1,000 J/m ² or more.

After exposure, the coating film may be heated again on a hot plate or the like before development. Heating conditions may be, for example, at 60°C or higher and 150°C or lower for 20 seconds or longer and 10 minutes or shorter.

[Step (3)]
In step (3), the coating film after exposure in step (2) is developed. Specifically, the coating film irradiated in step (2) is usually developed with a developer to remove the non-irradiated areas.

Examples of developing solutions include aqueous solutions of alkalis (basic compounds) such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5,4,0]-7-undecene, and 1,5-diazabicyclo[4,3,0]-5-nonane. Aqueous solutions in which an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant has been added to the aqueous solutions of the above alkalis, or aqueous alkali solutions containing small amounts of various other organic solvents may also be used as developing solutions.

In addition, compounds having a highly hydrophobic group, such as an alkyl group having 6 or more carbon atoms, have high solubility in organic solvents. Therefore, when such a compound is used as the [G1] guest compound or the [G2] guest compound, the dissolution contrast in the organic solvent between the non-exposed and exposed parts is increased, and the developability in organic solvent development is improved. For this reason, a developer containing an organic solvent can also be used as the developer. Examples of this organic solvent include the various solvents listed as optional components of the radiation-sensitive composition. In one embodiment of the present invention, the content of the organic solvent in the developer is preferably 50% by mass or more, more preferably 90% by mass or more, and even more preferably 99% by mass or more. This organic solvent-based developer may contain an inorganic solvent such as water and other additives.

As the developing method, for example, a suitable method such as a puddle method, a dipping method, a rocking immersion method, a shower method, a paddle method, etc. can be used. The developing time can be, for example, 20 seconds or more and 120 seconds or less.

After development, the patterned coating film may be rinsed with running water or the like.

If necessary, the coating can then be heated and baked (post-baked) to promote hardening of the coating.

According to the pattern forming method, a good pattern can be formed by exposure and development utilizing the radiation sensitivity of the radiation-sensitive composition. The pattern forming method can be used to form a resist pattern in photolithography. The pattern forming method can also be used to form various patterns of element components such as interlayer insulating films, spacers, protective films, and colored patterns for color filters.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the aspects of these examples.

A nuclear magnetic resonance apparatus (AVANCE700, manufactured by Bruker) was used for ¹ H-NMR and ¹³ C-NMR measurements for identifying the structure of the compound. The molecular weight of the monomer was measured using a liquid chromatograph mass spectrometer (LCMS-8045, manufactured by Shimadzu Corporation).
The molecular weights of the polymers (weight average molecular weight (Mw) and number average molecular weight (Mn)) were measured by gel permeation chromatography (GPC) under the following conditions. Mw/Mn was calculated from the obtained Mw and Mn.
Apparatus: GPC-101 (manufactured by Showa Denko)
Column: GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 (all manufactured by Showa Denko) Mobile phase: Tetrahydrofuran Column temperature: 40°C
Flow rate: 1.0 mL/min Sample concentration: 0.1% by mass
Sample injection volume: 100 μL
Detector: differential refractometer Standard material: monodisperse polystyrene The above analyses were performed and it was confirmed that the target compound had been obtained.
In the following synthesis examples of each polymer, the mass ratio of each monomer used was substantially equal to the content (mass ratio) of the corresponding structural unit in the resulting polymer.

Synthesis Example 1 Synthesis of acrylamidomethyl α-cyclodextrin (αCDAAmMe) Acrylamidomethyl α-cyclodextrin (αCDAAmMe) was synthesized according to the method described in WO2017/159346. Specifically, the synthesis was carried out according to the following procedure.
20 g (20 mmol) of α-cyclodextrin (αCD), 2 g (20 mmol) of N-hydroxymethylacrylamide, and 190 mg of p-toluenesulfonic acid monohydrate were weighed into a 300 mL round-bottom flask, and these were added to 50 mL of N,N-dimethylformamide (DMF) to prepare a reaction solution. This reaction solution was heated to 90°C in an oil bath and stirred. After stirring for 1 hour, the reaction solution was allowed to cool at room temperature and poured into 500 mL of acetone. The resulting precipitate was filtered off, washed with acetone, and dried under reduced pressure to obtain the reaction product.
Next, the reaction product was dissolved in 500 mL of distilled water and separated and purified by preparative high pressure liquid chromatography to separate unreacted α-cyclodextrin and αCDAAmMe.
The aqueous solution containing αCDAAmMe was extracted with an organic solvent, and the organic solvent was removed under reduced pressure to obtain the target product, αCDAAmMe (1.8 g of white powder).
The structure of the target substance was confirmed to be αCDAAmMe by ¹ H-NMR measurement, ¹³ C-NMR measurement and LC-MS measurement.

[Synthesis Example 2] Methoxylation of acrylamidomethyl α-cyclodextrin (αCDAAmMe) In a 300 mL round-bottom flask, αCDAAmMe obtained in Synthesis Example 1 was dissolved in N,N-dimethylformamide (DMF), and then sodium hydride was added and stirred for 1 hour. Methyl iodide was added dropwise from a dropping funnel and allowed to react for 1 hour. The hydroxyl group of αCDAAmMe was methoxylated.
Then, DMF was removed under reduced pressure, and the residue was purified by treating with dilute hydrochloric acid and water and repeatedly extracting with an organic solvent to obtain methoxylated acrylamidomethyl α-cyclodextrin (MeO-αCDAAmMe).

[Synthesis Example 3] Synthesis of acrylamidomethyl-β-cyclodextrin (βCDAAmMe) and its methoxylation Acrylamidemethyl-β-cyclodextrin (βCDAAmMe) was obtained by the same procedure as in Synthesis Example 1, except that α-cyclodextrin used in Synthesis Example 1 was replaced with β-cyclodextrin. Methoxylation of acrylamidomethyl-β-cyclodextrin (βCDAAmMe) was also performed by the same procedure as in Synthesis Example 2, to obtain methoxylated acrylamidomethyl-β-cyclodextrin (MeO-βCDAAmMe).

Synthesis Example 4 Synthesis of acrylamidomethyl γ-cyclodextrin (γCDAAmMe) and its methoxylation Acrylamidemethyl γ-cyclodextrin (γCDAAmMe) was obtained by the same procedure as in Synthesis Example 1, except that α-cyclodextrin used in Synthesis Example 1 was replaced with γ-cyclodextrin. Methoxylation of acrylamidomethyl γ-cyclodextrin (γCDAAmMe) was also performed by the same procedure as in Synthesis Example 2, to obtain methoxylated acrylamidomethyl γ-cyclodextrin (MeO-γCDAAmMe).

Synthesis Example 5 Synthesis of 4-vinylbenzylamine α-cyclodextrin (αCDVBA) and its methoxylation 20 g (20 mmol) of α-cyclodextrin, 2.7 g (20 mmol) of 4-vinylbenzylamine, and 190 mg of p-toluenesulfonic acid monohydrate were weighed into a 300 mL round-bottom flask, and these were added to 50 mL of N,N-dimethylformamide to prepare a reaction solution. This reaction solution was heated and stirred at 90° C. in an oil bath. After stirring for 1 hour, the reaction solution was allowed to cool at room temperature and poured into 500 mL of acetone. The resulting precipitate was filtered off, washed with acetone, and dried under reduced pressure to obtain a reaction product.
Next, the reaction product was dissolved in 500 mL of distilled water and separated and purified using preparative high pressure liquid chromatography to separate unreacted α-cyclodextrin and αCDVBA.
The aqueous solution containing α-CDVBA was extracted with an organic solvent, and the organic solvent was removed under reduced pressure to obtain the target product, α-CDVBA (2.2 g of white powder).
The structure of the target substance was confirmed to be the target αCDVBA by ¹ H-NMR measurement, ¹³ C-NMR measurement and LC-MS measurement.
Next, αCDVBA was methoxylated in the same manner as in Synthesis Example 2. It was confirmed that methoxylated 4-vinylbenzylamine α-cyclodextrin (MeO-αCDVBA) was obtained.

[Synthesis Example 6] Synthesis of MeO-αCDAAmMe/n-butyl acrylate/acrylic acid/styrene copolymer 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) were charged into a flask equipped with a cooling tube and a stirrer. Next, 10 parts by mass of MeO-αCDAAmMe obtained in Synthesis Example 2, 70 parts by mass of n-butyl acrylate, 15 parts by mass of acrylic acid, and 5 parts by mass of styrene were charged, and after nitrogen replacement, the temperature of the solution was raised to 90°C while gently stirring, and this temperature was maintained for 5 hours to polymerize. As a result, a polymer solution containing MeO-αCDAAmMe/n-butyl acrylate/acrylic acid/styrene (MeO-αCDAAmMe/BA/AA/ST) copolymer was obtained. This copolymer is referred to as polymer (A-1). The weight average molecular weight (Mw) of the polymer (A-1) was 5,000, and the Mw/Mn was 2.1.
The content ratio of the structural units derived from each component in the polymer (A-1) was MeO-αCDAAmMe/BA/AA/ST=10/70/15/5% by mass.

[Synthesis Example 7] Synthesis of MeO-αCDAAmMe/n-butyl acrylate/acrylic acid/styrene copolymer containing azobenzene as a guest compound Azobenzene (trans form) was dissolved in the polymer (A-1) solution obtained in Synthesis Example 6 so that the molar amount was equivalent to that of αCD in polymer (A-1), and the mixture was stirred at room temperature for 1 hour. As a result, a MeO-αCDAAmMe/n-butyl acrylate/acrylic acid/styrene (AzB MeO-αCDAAmMe/BA/AA/ST) copolymer containing azobenzene as a guest compound was obtained. This copolymer is referred to as polymer (AG-1).

Synthesis Example 8 Synthesis of MeO-αCDAAmMe/n-butyl acrylate/acrylic acid/styrene copolymer containing stilbene as guest compound Except for using stilbene (trans form) as the guest molecule, the same procedure as in Synthesis Example 7 was carried out to obtain a MeO-αCDAAmMe/n-butyl acrylate/acrylic acid/styrene (StB MeO-αCDAAmMe/BA/AA/ST) copolymer containing stilbene as the guest compound. This copolymer is referred to as polymer (AG-2).

[Synthesis Example 9] Synthesis of MeO-γCDAAmMe/n-butyl acrylate/acrylic acid/styrene copolymer containing 4-methoxyazobenzene as a guest compound (1) The same procedure as in Synthesis Example 6 was carried out except that MeO-γCDAAmMe obtained in Synthesis Example 4 was used instead of MeO-αCDAAmMe, and a polymer solution containing MeO-γCDAAmMe/n-butyl acrylate/acrylic acid/styrene (MeO-γCDAAmMe/BA/AA/ST) copolymer was obtained. This copolymer is referred to as polymer (A-3a). The content ratio of the structural units derived from each component in polymer (A-3a) was MeO-γCDAAmMe/BA/AA/ST=10/70/15/5% by mass.
Furthermore, a MeO-γCDAAmMe/n-butyl acrylate/acrylic acid/styrene (4-MeOAzB MeO-γCDAAmMe/BA/AA/ST) copolymer containing 4-methoxyazobenzene (trans form) as a guest molecule was obtained in the same manner as in Synthesis Example 7. The obtained copolymer is designated polymer (AG-3a).
(2) The same procedure as in Synthesis Example 6 was carried out except that MeO-βCDAAmMe obtained in Synthesis Example 3 was used instead of MeO-αCDAAmMe, and a polymer solution containing a MeO-βCDAAmMe/n-butyl acrylate/acrylic acid/styrene (MeO-βCDAAmMe/BA/AA/ST) copolymer was obtained. This copolymer is designated as polymer (A-3b). The content ratio of the structural units derived from each component in polymer (A-3b) was MeO-βCDAAmMe/BA/AA/ST=10/70/15/5% by mass.
Furthermore, a MeO-βCDAAmMe/n-butyl acrylate/acrylic acid/styrene (4-MeOAzB MeO-βCDAAmMe/BA/AA/ST) copolymer containing 4-methoxyazobenzene (trans form) as a guest molecule was obtained in the same manner as in Synthesis Example 7. The obtained copolymer is designated polymer (AG-3b).

[Synthesis Example 10] Synthesis of MeO-αCDVBA/benzyl acrylate/acrylic acid/styrene copolymer]
A flask equipped with a cooling tube and a stirrer was charged with 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA). Next, 10 parts by mass of MeO-αCDVBA obtained in Synthesis Example 5, 70 parts by mass of benzyl acrylate (BzA), 15 parts by mass of acrylic acid (AA) and 5 parts by mass of styrene (ST) were charged, and after nitrogen replacement, the temperature of the solution was raised to 90°C while gently stirring, and this temperature was maintained for 5 hours to polymerize. As a result, a polymer solution containing MeO-αCDVBA/benzyl acrylate/acrylic acid/styrene (MeO-αCDVBA/BzA/AA/ST) copolymer was obtained. This copolymer was designated polymer (A-4). The weight average molecular weight (Mw) of polymer (A-4) was 4,000, and Mw/Mn was 2.3. The content ratio of the structural units derived from each component in the polymer (A-4) was MeO-αCDVBA/BzA/AA/ST=10/70/15/5% by mass.

Synthesis Example 11 Synthesis of MeO-αCDVBA/benzyl acrylate/acrylic acid/styrene copolymer containing azobenzene as a guest compound A MeO-αCDVBA/benzyl acrylate/acrylic acid/styrene (AzB MeO-αCDVBA/BzA/AA/ST) copolymer containing azobenzene (trans form) as a guest molecule was obtained from polymer (A-4) obtained in Synthesis Example 10 in the same manner as in Synthesis Example 7. The obtained copolymer is referred to as polymer (AG-4).

Synthesis Example 12 Synthesis of MeO-αCDVBA/benzyl acrylate/acrylic acid/styrene copolymer containing stilbene as guest compound Except for using stilbene (trans form) as the guest molecule, the same procedure as in Synthesis Example 11 was carried out to obtain a MeO-αCDVBA/benzyl acrylate/acrylic acid/styrene (StB MeO-αCDVBA/BzA/AA/ST) copolymer containing stilbene as the guest compound. This copolymer is referred to as polymer (AG-5).

[Synthesis Example 13] Synthesis of adamantyl acrylate / benzyl acrylate / methyl acrylate copolymer 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) were charged into a flask equipped with a cooling tube and a stirrer. Next, 60 parts by mass of adamantyl acrylate (AdA), 20 parts by mass of benzyl acrylate (BzA) and 20 parts by mass of methyl acrylate (MeA) were charged, and after nitrogen replacement, the temperature of the solution was raised to 90 ° C. while stirring gently, and this temperature was maintained for 5 hours to polymerize. As a result, a polymer solution containing AdA / BzA / MA copolymer was obtained. This copolymer is polymer (G-1). The weight average molecular weight (Mw) of polymer (G-1) was 10,000, and Mw / Mn was 1.8. The content ratio of the structural units derived from each component in the polymer (G-1) was AdA/BzA/MeA=60/20/20% by mass.

Synthesis Example 14 Synthesis of Copolymer Obtained by Reacting Adamantyl Methacrylate/Methyl Methacrylate/Methacrylic Acid Copolymer with Glycidyl Methacrylate A flask equipped with a cooling tube and a stirrer was charged with 4 parts by mass of 2,2'-azobisisobutyronitrile and 190 parts by mass of propylene glycol monomethyl ether acetate, followed by 35 parts by mass of adamantyl methacrylate (AdMA), 15 parts by mass of methyl methacrylate (MeMA), and 50 parts by mass of methacrylic acid (MA). With gentle stirring, the temperature of the solution was raised to 80°C, maintained at this temperature for 4 hours, and then raised to 100°C and maintained at this temperature for 1 hour to polymerize, thereby obtaining a solution containing a copolymer. Next, 1.1 parts by mass of tetrabutylammonium bromide and 0.05 parts by mass of 4-methoxyphenol as a polymerization inhibitor were added to the solution containing this copolymer, and the mixture was stirred at 90° C. for 30 minutes under an air atmosphere, and then 35 parts by mass of glycidyl methacrylate was added and reacted at 90° C. for 10 hours to obtain a polymer solution containing a copolymer in which glycidyl methacrylate (GMA) was reacted with an adamantyl methacrylate/methyl methacrylate/methacrylic acid copolymer. This copolymer is designated as polymer (G-2). The weight average molecular weight (Mw) of polymer (G-2) was 12,000, and Mw/Mn was 1.9. The content ratio of structural units derived from each component in polymer (G-2) was AdMA/MeMA/MA/MA-GMA=26/11/11/52% by mass.

[Synthesis Example 15] Synthesis of adamantyl methacrylate / glycidyl methacrylate / methacrylic acid copolymer 5.3 parts by mass of 2,2'-azobis-(2,4-dimethylvaleronitrile) and 200 parts by mass of diethylene glycol methyl ethyl ether were charged into a flask equipped with a cooling tube and a stirrer. Subsequently, 52 parts by mass of adamantyl methacrylate (AdMA), 30 parts by mass of glycidyl methacrylate (GMA), 18 parts by mass of methacrylic acid (MA), and 0.5 parts by mass of α-methylstyrene dimer were charged and substituted with nitrogen, and then gentle stirring was started. The temperature of the solution was raised to 70 ° C. and maintained at this temperature for 5 hours to obtain a polymer solution containing adamantyl methacrylate / glycidyl methacrylate / methacrylic acid copolymer. This copolymer is referred to as polymer (G-3). The weight average molecular weight (Mw) of polymer (G-3) was 10,000, and Mw / Mn was 2.3. The content ratio of the structural units derived from each component in the polymer (G-3) was AdMA/GMA/MA=52/30/18% by mass.

[Synthesis Example 16] Synthesis of ethyl adamantyl acrylate / benzyl acrylate / methyl acrylate copolymer 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) were charged into a flask equipped with a cooling tube and a stirrer. Next, 50 parts by mass of ethyl adamantyl acrylate (EtAdA), 20 parts by mass of benzyl acrylate (BzA) and 30 parts by mass of methyl acrylate (MeA) were charged, and after nitrogen replacement, the temperature of the solution was raised to 90 ° C. while stirring gently, and this temperature was maintained for 5 hours to polymerize. As a result, a polymer solution containing an ethyl adamantyl acrylate / benzyl acrylate / methyl acrylate copolymer was obtained. This copolymer is called (G-4). The weight average molecular weight (Mw) of the polymer (G-4) was 9,000, and Mw / Mn was 2.1. The content ratio of the structural units derived from each component in the polymer (G-4) was EtAdA/BzA/MeA=50/20/30% by mass.

[Synthesis Example 17] Synthesis of cyclohexyl adamantyl acrylate / benzyl acrylate / methyl acrylate copolymer A flask equipped with a cooling tube and a stirrer was charged with 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA). Next, 50 parts by mass of cyclohexyl adamantyl acrylate (HeAdA), 20 parts by mass of benzyl acrylate (BzA) and 30 parts by mass of methyl acrylate (MeA) were charged, and after nitrogen replacement, the temperature of the solution was raised to 90 ° C. while stirring gently, and this temperature was maintained for 5 hours to polymerize. As a result, a polymer solution containing cyclohexyl adamantyl acrylate / benzyl acrylate / methyl acrylate copolymer was obtained. This copolymer is polymer (G-5). The weight average molecular weight (Mw) of polymer (G-5) was 8,000, and Mw / Mn was 2.2. The content ratio of the structural units derived from each component in the polymer (G-5) was HeAdA/BzA/MeA=50/20/30% by mass.

[Synthesis Example 18] Synthesis of benzyl acrylate / methyl acrylate / n-butyl acrylate copolymer A flask equipped with a cooling tube and a stirrer was charged with 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA). Next, 60 parts by mass of benzyl acrylate (BzA), 20 parts by mass of methyl acrylate (MeA) and 20 parts by mass of n-butyl acrylate (BA) were charged, and after nitrogen replacement, the temperature of the solution was raised to 90 ° C. while stirring gently, and this temperature was maintained for 5 hours to polymerize. This resulted in a polymer solution containing a benzyl acrylate / methyl acrylate / n-butyl acrylate copolymer. This copolymer was polymer (G-6). The weight average molecular weight (Mw) of polymer (G-6) was 7,000, and Mw / Mn was 2.0. The content ratio of the structural units derived from each component in the polymer (G-6) was BzA/MeA/BA=60/20/20% by mass.

Comparative Synthesis Example 1: Synthesis of methyl methacrylate/methacrylic acid/ethyl methacrylate copolymer A flask equipped with a cooling tube and a stirrer was charged with 8 parts by mass of azobisisobutyronitrile (AIBN) and 200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA). Next, 20 parts by mass of methyl methacrylate (MeMA), 20 parts by mass of methacrylic acid (MA) and 60 parts by mass of ethyl methacrylate (EtMA) were charged, and after nitrogen replacement, the temperature of the solution was raised to 90° C. while gently stirring, and this temperature was maintained for 5 hours to polymerize. This resulted in a polymer solution containing a methyl methacrylate/methacrylic acid/ethyl methacrylate copolymer. This copolymer was designated polymer (g-1). The weight average molecular weight (Mw) of polymer (g-1) was 8,000, and Mw/Mn was 1.8. The content ratio of the structural units derived from each component in the polymer (g-1) was MeMA/MA/EtMA=20/20/60% by mass.

<Preparation of Radiation-Sensitive Composition>
The components used in preparing the radiation-sensitive composition are shown below.
[A] Polymer (A-1) Polymer obtained in Synthesis Example 6 MeO-αCDAAmMe/BA/AA/ST copolymer (A-4) Polymer obtained in Synthesis Example 10 MeO-αCDVBA/BzA/AA/ST copolymer

Inclusion compound of polymer [A] and photoreactive compound [G1-2] (AG-1) Polymer obtained in Synthesis Example 7 AzB MeO-αCDAAmMe/BA/AA/ST copolymer (AG-2) Polymer obtained in Synthesis Example 8 StB MeO-αCDAAmMe/BA/AA/ST copolymer (AG-3a) Polymer obtained in Synthesis Example 9 (1) 4-MeOAzB MeO-γCDAAmMe/BA/AA/ST copolymer (AG-3b) Polymer obtained in Synthesis Example 9 (2) 4-MeOAzB MeO-βCDAAmMe/BA/AA/ST copolymer (AG-4) Polymer obtained in Synthesis Example 11 AzB MeO-αCDVBA/BzA/AA/ST copolymer (AG-5) Polymer obtained in Synthesis Example 12 StB MeO-αCDVBA/BzA/AA/ST copolymer

[G2] Polymer or Comparative Polymer (G-1) Polymer obtained in Synthesis Example 13 Adamantyl acrylate/benzyl acrylate/methyl acrylate (AdA/BzA/MeA) copolymer (G-2) Polymer obtained in Synthesis Example 14 Adamantyl methacrylate/methyl methacrylate/methacrylic acid copolymer reacted with glycidyl methacrylate (AdMA/MeMA/MA/MA-GMA) copolymer (G-3) Polymer obtained in Synthesis Example 15 Adamantyl methacrylate/glycidyl methacrylate/methacrylic acid (AdMA/GMA/MA) copolymer (G-4) Polymer obtained in Synthesis Example 16 Ethyl adamantyl acrylate/benzyl acrylate/methyl acrylate (EtAdA/BzA/MeA) copolymer (G-5) Polymer obtained in Synthesis Example 17 Cyclohexyladamantyl acrylate/benzyl acrylate/methyl acrylate (HeAdA/BzA/MeA) copolymer (G-6) Polymer obtained in Synthesis Example 18 Benzyl acrylate/methyl acrylate/n-butyl acrylate (BzA/MeA/BA) copolymer (g-1) Polymer obtained in Comparative Synthesis Example 1 Methyl methacrylate/methacrylic acid/ethyl methacrylate (MeMA/MA/EtMA) copolymer

[G1-1] Crosslinkable compound (G1-1) Adamantyl acrylate

[B] Polymerizable compound (B-1): 1,6-hexanediol diacrylate (B-2): Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate ("KAYARAD DPHA" from Nippon Kayaku Co., Ltd.)

[C] Radiation-sensitive polymerization initiator (polymerization initiator)
(C-1) Ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) (BASF "Irgacure OXE-02")
(C-2) (N-(trifluoromethylsulfonyloxy)-1,8-naphthalene dicarbimide ("NAI-105" manufactured by Midori Chemical Industry Co., Ltd.)

[Example 1]
100 parts by mass of polymer (A-1) as the polymer [A] and 30 parts by mass of adamantyl acrylate (G1-1) as the crosslinkable compound [G1-1] were dissolved in propylene glycol monomethyl ether acetate, 0.01 parts by mass of SH 190 (manufactured by Toray Dow Corning Silicone) as a surfactant was added, and the mixture was mixed and stirred at room temperature for 30 minutes. Then, 30 parts by mass of 1,6-hexanediol di(meth)acrylate (B-1) as the polymerizable compound [B] and 5 parts by mass of ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) as the polymerization initiator [C] were added, dissolved, and filtered using a filter with a pore size of 0.2 μm to prepare the composition (T-1) of Example 1.

[Examples 2 to 3, Comparative Example 1]
Compositions (T-2) to (T-3) of Examples 2 and 3 and composition (t-1) of Comparative Example 1 were prepared in the same manner as in Example 1, except that the types and amounts of the polymer [A], the crosslinkable compound [G1-1], the polymerizable compound [B], and the polymerization initiator [C] were as shown in Table 1. In Table 1, "-" indicates that no addition was made.

[Example 4]
50 parts by mass of polymer (AG-1) as an inclusion compound of polymer [A] and photoreactive compound [G1-2], and 50 parts by mass of polymer (G-1) as polymer [G2] were dissolved in propylene glycol monomethyl ether acetate, 0.01 parts by mass of SH 190 (manufactured by Toray Dow Corning Silicone) was added as a surfactant, and the mixture was mixed and stirred, and then filtered using a filter with a pore size of 0.2 μm, to prepare composition (T-4) of Example 4.

[Example 5]
50 parts by mass of polymer (AG-1) as an inclusion compound of the polymer [A] and the photoreactive compound [G1-2], 50 parts by mass of polymer (G-2) as the polymer [G2], and 5 parts by mass of (C-1) ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) as the polymerization initiator [C] were added and dissolved in propylene glycol monomethyl ether acetate. Furthermore, 0.01 parts by mass of SH 190 (manufactured by Toray Dow Corning Silicone) was added as a surfactant, mixed and stirred, and then filtered using a filter with a pore size of 0.2 μm to prepare the composition (T-5) of Example 5.

[Examples 6 to 13, Comparative Example 2]
Compositions (T-6) to (T-13) of Examples 6 to 13 and composition (t-2) of Comparative Example 2 were prepared in the same manner as in Example 5, except that the types and amounts of the inclusion compound of the polymer [A] and the photoreactive compound [G1-2] or the polymer [A], the polymer [G2] or the comparative polymer, and the polymerization initiator [C] were as shown in Table 2. In Table 2, "-" indicates that no addition was made.

<Formation of Resist Pattern>
A bottom antireflection film ("ARC66" manufactured by Brewer Science) was applied onto an 8-inch silicon wafer using a spin coater ("CLEAN TRACK Lithius Pro i" manufactured by Tokyo Electron Ltd.), and then heated at 205°C for 60 seconds to form a bottom antireflection film with a thickness of 0.15 µm.
Next, using the spin coater, each composition shown in Tables 1 and 2 was applied, and PB was carried out at 90° C. for 60 seconds, followed by cooling at 23° C. for 30 seconds to form a coating film having a thickness of 2.0 μm.
Next, the coating film was exposed to light using an i-line exposure device (manufactured by Nikon Seiki Co., Ltd.) or a KrF exposure device (manufactured by Nikon Seiki Co., Ltd.) Thereafter, the coating film was heated on a hot plate at a temperature of 120° C. for 60 seconds, and then cooled at 23° C. for 30 seconds.
The coating was then paddle-developed for 30 seconds with a given developer. After development, the coating was rinsed with pure water to obtain a pattern. The length was measured using a scanning electron microscope (CG4000, manufactured by Hitachi High-Technologies Corporation).
In the exposure step, an i-line exposure device and a KrF exposure device were used depending on the guest compound used. Specifically, an i-line exposure device was used for the composition containing an azobenzene compound as the guest compound. A KrF exposure device was used for the other compositions.

<Evaluation>
The resist patterns formed as described above were subjected to the following various evaluations. The evaluation results are shown in Tables 1 and 2. It should be noted that the composition of Comparative Example 2 did not exhibit radiation sensitivity, and a resist pattern could not be formed by the above method.

[sensitivity]
The optimum exposure amount was determined as the exposure amount at which the line pattern formed by the above pattern forming method had a line of 1 μm/pitch of 2 ^μm , and this optimum exposure amount was determined as the sensitivity (mJ/ ^cm2 ). A sensitivity of 160 mJ/cm2 or less was determined to be sufficiently usable as a radiation-sensitive pattern forming material, and a sensitivity of 100 mJ/cm2 or ^less was determined to be particularly good.

[Exposure latitude (EL)]
Exposure was performed through a mask that would result in a line pattern of 1 μm line/2 μm pitch after reduced projection exposure, and the ratio of the range of exposure dose when the line width of the formed line pattern was within ±15% of the 1 μm line to the optimal exposure dose was defined as the exposure latitude (EL (%)). An EL value of 4% or more was determined to be sufficiently usable as a radiation-sensitive pattern forming material, and an EL value of 15% or more was determined to be particularly good, with small variation in patterning performance relative to changes in exposure dose.

[Depth Of Focus (DOF)]
The exposure was performed through a mask that would result in a line pattern of 1 μm line/2 μm pitch after reduced projection exposure, and the focus deviation when the line width of the formed line pattern was within ±10% of the 1 μm line was defined as the depth of focus (DOF (μm)). When the DOF value was 0.3 μm or more, it was determined that the variation in patterning performance with respect to focus change was small and good.

[LWR (Line Width Roughness)]
The 1 μm line/2 μm pitch line pattern resolved with the above optimal exposure dose was observed from above the pattern using a scanning electron microscope (CG4000, manufactured by Hitachi High-Technologies Corporation). The line width was measured at 50 arbitrary points in total, and the measurement variation was calculated as 3 sigma to obtain the LWR. A value of 0.1 μm or less was judged to be good.

[Film loss amount]
In the same manner as in the above sensitivity evaluation, a line pattern of 1 μm line/2 μm pitch was formed. The resist was developed with 2.38% TMAH developer at 23° C. for 60 seconds and dried. After the series of processes were completed, the thickness of the remaining resist film was measured, and the value obtained by subtracting the remaining film thickness from the initial film thickness was taken as the film loss amount. The film thickness was measured using an optical interference film thickness measuring device (Lambda Ace, manufactured by Dainippon Screen Mfg. Co., Ltd.). The initial film thickness is the film thickness before exposure after coating on the substrate. When the measured film loss amount was 0.8 μm or less, the film loss amount was judged to be sufficiently small, and when it was 0.3 μm or less, it was judged to be particularly good.

[Heat resistance evaluation]
The composition was applied onto a substrate and then dried to form a coating film. The resulting coating film was exposed to light without a pattern mask. The thickness (T1) of the resulting cured film was measured. The substrate on which the cured film was formed was then heated in a clean oven at 200°C for 30 minutes, and the thickness (t1) of the cured film was then measured. The thickness change rate of the cured film {|t1-T1|/T1} x 100 [%] was calculated. When this value was 12% or less, the heat resistance was judged to be sufficient, and when it was 5% or less, the heat resistance was judged to be particularly good.

As shown in Tables 1 and 2, it is understood that each of the compositions of Examples 1 to 13 can be used as a pattern-forming material having radiation sensitivity. Among these, each of the compositions of Examples 1 to 12 was found to be particularly preferable as a pattern-forming material, since it was evaluated to be favorable in terms of sensitivity, exposure latitude, depth of focus, LWR, film loss amount, and heat resistance.
In addition, since the compositions of Examples 1 to 3 exhibit higher sensitivity, heat resistance, etc. than the composition of Comparative Example 1, it is presumed that a crosslinked structure is formed between the polymers [A]. That is, it is presumed that an inclusion compound is formed in which adamantyl acrylate (G1-1) as shown in the following formula is included in the host group of the polymer [A], and that a crosslinked structure is formed between the inclusion compounds as a result of the crosslinkable group of adamantyl acrylate (G1-1) in the inclusion compound reacting upon exposure to light.

The radiation-sensitive composition of the present invention can be suitably used as a pattern-forming material for forming a resist pattern or the like.

Claims (23)

forming a coating film on a substrate using a radiation-sensitive composition containing a polymer having a host group and a first guest compound;
The method includes a step of exposing the coating film to light, and a step of developing the coating film after exposure,
The pattern forming method, wherein the host group is a monovalent group obtained by removing one hydrogen atom or hydroxyl group from a cyclodextrin derivative. The pattern formation method according to claim 1, wherein the cyclodextrin derivative has a structure in which the hydrogen atom of the hydroxyl group of the cyclodextrin is substituted with at least one group selected from the group consisting of a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, and -CONHR, wherein R is a methyl group or an ethyl group. The pattern forming method according to claim 2, wherein the cyclodextrin is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin. A pattern forming method according to claim 1, claim 2 or claim 3, wherein at least a portion of the first guest compound is encapsulated in the host group. A pattern forming method according to any one of claims 1 to 4, wherein the first guest compound is a compound having a crosslinkable group or a photoreactive compound. the first guest compound is a compound having the crosslinkable group,
6. The pattern forming method according to claim 5, wherein the compound having a crosslinkable group further has a hydrocarbon group having 6 to 30 carbon atoms. the first guest compound is a photoisomerizable compound that is the photoreactive compound,
6. The pattern formation method according to claim 5, wherein the photoisomerizable compound is an azobenzene, a stilbene, or a compound in which at least one hydrogen atom of these is substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. the first guest compound is a photoreactive compound at least a portion of which is included in the host group;
8. The method for forming a pattern according to claim 4, wherein the radiation-sensitive composition further contains a second guest compound that is not encapsulated in the host group. The pattern formation method according to claim 8, wherein the exposure causes at least a portion of the first guest compound to be released from the host group and at least a portion of the second guest compound to be included in the host group. A pattern forming method as described in claim 8 or claim 9, wherein the second guest compound is a polymer containing a structural unit having a hydrocarbon group having 6 to 30 carbon atoms. The pattern formation method according to any one of claims 1 to 10, wherein the exposure step is carried out with radiation having at least one of the wavelengths of 246 nm and 365 nm. The composition comprises a polymer having a host group and a first guest compound,
The radiation-sensitive composition for pattern formation, wherein the host group is a monovalent group formed by removing one hydrogen atom or hydroxyl group from a cyclodextrin derivative. The radiation-sensitive composition according to claim 12, wherein the cyclodextrin derivative has a structure in which the hydrogen atom of a hydroxyl group of cyclodextrin is substituted with at least one group selected from the group consisting of a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, and -CONHR, and the R is a methyl group or an ethyl group. The radiation-sensitive composition according to claim 13, wherein the cyclodextrin is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin. The radiation-sensitive composition according to claim 12, claim 13 or claim 14, wherein at least a portion of the first guest compound is encapsulated in the host group. The radiation-sensitive composition according to any one of claims 12 to 15, wherein the first guest compound is a compound having a crosslinkable group or a photoreactive compound. the first guest compound is a compound having the crosslinkable group,
17. The radiation-sensitive composition according to claim 16, wherein the compound having a crosslinkable group further has a hydrocarbon group having 6 to 30 carbon atoms. the first guest compound is a photoisomerizable compound that is the photoreactive compound,
17. The radiation-sensitive composition according to claim 16, wherein the photoisomerizable compound is an azobenzene, a stilbene, or a compound in which at least one hydrogen atom of these is substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. the first guest compound is a photoreactive compound at least a portion of which is included in the host group;
19. The radiation-sensitive composition according to claim 15, further comprising a second guest compound that is not included in the host group. The radiation-sensitive composition described in claim 19, wherein the second guest compound is a polymer containing a structural unit having a hydrocarbon group having 6 to 30 carbon atoms. An inclusion compound in which at least a part of a first guest compound is included in a host group of a polymer having a host group,
the host group is a monovalent group obtained by removing one hydrogen atom or one hydroxyl group from a cyclodextrin derivative,
The cyclodextrin derivative has a structure in which a hydrogen atom of at least one hydroxyl group of cyclodextrin is substituted with at least one group selected from the group consisting of a monovalent hydrocarbon group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, and -CONHR, wherein R is a methyl group or an ethyl group;
The first guest compound is an inclusion compound having a crosslinkable group and a hydrocarbon group having 6 to 30 carbon atoms. 22. The inclusion compound of claim 21, wherein the polymer comprises a structural unit represented by the following formula (1):

In formula (1), R ¹ is a hydrogen atom or a methyl group. R ² is a divalent linking group. R ³ is a group represented by -O- or -NR ⁴ -. R ⁴ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^H is the above-mentioned host group. 23. The inclusion compound of claim 21 or claim 22, wherein the first guest compound is adamantyl (meth)acrylate.