Method for using degradable film and method for producing resist pattern

Abstract

A method for using a degradable film, comprising the steps of: preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or base upon irradiation with energy rays, the degradable film having a content of adhesive resins other than the aliphatic polycarbonate of 10% by mass or less; irradiating the entire surface or a portion of the degradable film in a planar view with energy rays; and heating the degradable film to decompose the entire surface or a portion of the degradable film in a planar view. This method for using a degradable film allows the degradable film to be easily decomposed.

Description

[Technical Field]

[0001] The present invention relates to a method for using a degradable film and a method for producing a resist pattern. [Background technology]

[0002] Photolithography has traditionally been used to form patterns on thin films and the like using light, and resist is used to form these patterns. There are negative and positive types of photolithography. In negative types, the pattern is formed in the areas that are exposed to light, while in positive types, the pattern is formed in the areas that are not exposed to light. When photolithography was first developed, negative types were the mainstream, but now positive types, which use highly sensitive resists, are the mainstream.

[0003] As a positive resist, for example, a chemically amplified positive photosensitive composition has been proposed in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2022-129980 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional photoresists require a development step using a developer and pure water to form a pattern after exposure, but a dry process is desirable from the standpoint of improving the working environment and preventing environmental pollution.

[0006] An object of the present invention is to provide a method for using a degradable film that allows the film to be easily decomposed, and a method for producing a resist pattern that allows a resist pattern to be easily produced. [Means for solving the problem]

[0007] In order to achieve the above object, first, the present invention provides a method for using a degradable film, comprising the steps of: preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays, wherein the content of adhesive resins other than the aliphatic polycarbonate is 10 mass % or less; irradiating the entire surface or a part of the degradable film in a planar view with energy rays; and decomposing the entire surface or a part of the degradable film in a planar view by heating the degradable film (Invention 1).

[0008] Second, the present invention provides a method for using a degradable film, comprising the steps of: preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; irradiating the entire surface or a part of the degradable film in plan view with energy rays; and heating the degradable film at a temperature of 30°C or higher and 120°C or lower to decompose the entire surface or a part of the degradable film in plan view (Invention 2).

[0009] In the above inventions (Inventions 1 and 2), when the degradable film is irradiated with energy rays, an acid or base is generated by the action of the acid / base generator. The action of this generated acid or base lowers the backbiting initiation temperature of the aliphatic polycarbonate, allowing the aliphatic polycarbonate to decompose even at a relatively low temperature. By heating the degradable film in this state, the aliphatic polycarbonate is effectively thermally decomposed, and the degradable film itself is also decomposed. Thus, according to the above method of using the degradable film, the degradable film can be easily decomposed, and if desired, the degradable film can be decomposed at a relatively low temperature.

[0010] In the above inventions (Inventions 1 and 2), it is preferable that the energy rays irradiated in the irradiation step include energy rays having at least a part of the wavelength range of 150 to 400 nm (Invention 3).

[0011] In the above inventions (Inventions 1 to 3), the amount of energy rays irradiated in the irradiation step is 50 mJ / cm 2 More than 1500mJ / cm 2 It is preferable that the following is true (Invention 4):

[0012] In the above inventions (Inventions 1 to 4), the heating time in the decomposition step is preferably 1 minute or more and 30 minutes or less (Invention 5).

[0013] In the above inventions (Inventions 1 to 5), the acid / base generator is an acid generator that generates an acid upon irradiation with energy rays, and the acid generator has a sulfonium salt structure and a molar absorption coefficient of 50 M or less for energy rays having a wavelength of 365 nm. -1 cm -1 It is preferable that the above is true (Invention 6).

[0014] In the above inventions (Inventions 1 to 5), the acid / base generator is a base generator that generates a base upon irradiation with energy rays, and the base generator has a biguanide salt structure and a molar absorption coefficient of 50 M or less with respect to energy rays having a wavelength of 365 nm. -1 cm -1 It is preferable that the above is true (Invention 7).

[0015] In the above inventions (Inventions 1 to 7), the degradable film preferably contains 0.01 parts by mass or more and 10 parts by mass or less of the acid / base generator per 100 parts by mass of the aliphatic polycarbonate (Invention 8).

[0016] In the above inventions (Inventions 1 to 8), the aliphatic polycarbonate preferably has a structural unit represented by the following general formula (1a) (Invention 9). [ka] (In the formula, R 1 , R 2 , R 3 and R 4each independently represents a hydrogen atom, a linear hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 8 carbon atoms, or an aromatic hydrocarbon group having 6 to 8 carbon atoms.

[0017] In the above inventions (Inventions 1 to 9), the aliphatic polycarbonate preferably has a glass transition temperature of −40° C. or higher and 150° C. or lower (Invention 10).

[0018] In the above inventions (Inventions 1 to 10), the weight average molecular weight of the aliphatic polycarbonate is preferably 2,000 or more and 1,000,000 or less (Invention 11).

[0019] In the above inventions (Inventions 1 to 11), the thickness of the degradable film is preferably 1 μm or more and 50 μm or less (Invention 12).

[0020] Third, the present invention provides a method for producing a resist pattern, comprising the steps of: preparing a decomposable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; irradiating a portion of the decomposable film in a planar view with energy rays; and decomposing the portion of the decomposable film in a planar view by heating the decomposable film (Invention 13). [Effects of the Invention]

[0021] According to the method for using a degradable film of the present invention, the degradable film can be easily decomposed, and according to the method for producing a resist pattern of the present invention, a resist pattern can be easily produced. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described. [How to use degradable film] A method for using a degradable film according to a first embodiment of the present invention includes the steps of: preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays, the degradable film having a content of adhesive resins other than the aliphatic polycarbonate of 10% by mass or less; irradiating the entire surface or a portion of the degradable film in a planar view with energy rays; and decomposing the degradable film by heating the degradable film to decompose the entire surface or a portion of the degradable film in a planar view.

[0023] A method for using a degradable film according to a second embodiment of the present invention includes the steps of: preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; irradiating the entire surface or a portion of the degradable film in plan view with energy rays; and decomposing the degradable film at a temperature of 30°C or higher and 120°C or lower to decompose the entire surface or a portion of the degradable film in plan view.

[0024] In the above method, when the decomposable film is irradiated with energy rays, an acid or base is generated by the action of the acid / base generator. The action of the generated acid or base lowers the backbiting initiation temperature of the aliphatic polycarbonate, allowing the aliphatic polycarbonate to decompose even at relatively low temperatures. Heating the decomposable film in this state effectively thermally decomposes the aliphatic polycarbonate, and the decomposable film itself also decomposes. Thus, according to the above method of using the decomposable film, the decomposable film can be easily decomposed, and if desired, the decomposable film can be decomposed at a relatively low temperature. Furthermore, by irradiating the decomposable film with energy rays in a desired pattern, the decomposable film can be decomposed in the desired pattern. In other words, a desired pattern (a pattern that is the inverse of the decomposed pattern) can be easily formed by a dry process that does not require a liquid development step.

[0025] 1. Prepare degradable film The degradable film used in this embodiment contains an aliphatic polycarbonate and an acid / base generator that generates an acid or base upon irradiation with energy rays. In the degradable film, the content of adhesive resins other than the aliphatic polycarbonate is preferably 10% by mass or less, more preferably 7% by mass or less, particularly preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, and most preferably 0% by mass. This reduces the amount of residue remaining after the decomposition step.

[0026] 1-1. Each ingredient (1) Aliphatic polycarbonate (1-1) Structure of Aliphatic Polycarbonate The aliphatic polycarbonate used in the degradable film of this embodiment is a polycarbonate whose main chain is composed of a carbonate group (-O-C(=O)-O-) and an aliphatic group, and has a structure in which the divalent aliphatic groups constituting the main chain are linked by carbonate groups.

[0027] The aliphatic polycarbonate may have a carboxylic acid ester bond (-C(=O)-O-) in its main chain, but preferably does not. When the aliphatic polycarbonate does not have a carboxylic acid ester bond in its main chain, the aliphatic polycarbonate does not include a polymer having a polycarbonate skeleton obtained by reacting a carboxylic acid or its derivative with an alcohol to form an ester bond in the main chain. Here, examples of the carboxylic acid derivative include carboxylic acid anhydrides and carboxylic acid halides, which are capable of forming an ester bond.

[0028] Furthermore, the aliphatic polycarbonate may have a urethane bond (—NH—C(═O)—O—) in its main chain, but preferably does not have one. When the aliphatic polycarbonate does not have a urethane bond in its main chain, the aliphatic polycarbonate does not include a polymer having a polycarbonate skeleton obtained by reacting a compound having an isocyanate group with an alcohol to form a urethane bond in the main chain.

[0029] Furthermore, the aliphatic polycarbonate may have an ether bond (—O—) in its main chain.

[0030] The aliphatic polycarbonate may or may not have either or both of a carboxylic acid ester bond and a urethane bond in its side chain.

[0031] The aliphatic polycarbonate may, for example, be one having a structural unit represented by the following general formula (1).

[0032] [ka] (In the formula, X is an unsubstituted or substituted divalent aliphatic hydrocarbon group.)

[0033] In the formula, X is an unsubstituted or substituted divalent aliphatic hydrocarbon group, and the aliphatic hydrocarbon group may be linear, branched, or cyclic, or may have both a linear structure and a cyclic structure. The cyclic aliphatic hydrocarbon group may be monocyclic or polycyclic.

[0034] Regarding X, the aliphatic hydrocarbon group "having a substituent" means an aliphatic hydrocarbon group in which one or more hydrogen atoms have been substituted with a group (substituent) other than a hydrogen atom.

[0035] When the aliphatic hydrocarbon group has a substituent, the substituent is not particularly limited, and examples thereof include a hydroxy group, a carboxy group, a halogen atom, an alkoxy group, an alkenyl group, an alkenyloxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, an alkylsilyl group, an alkylsilyloxy group, etc. Thus, the aliphatic polycarbonate may or may not have an aromatic group in a side chain branching from the main chain, as long as the only groups other than the carbonate groups constituting the main chain are aliphatic groups.

[0036] Examples of the halogen atom in the above substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0037] Examples of the alkoxy group in the above substituent include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a cyclopropoxy group, and a cyclobutoxy group, and the like, and R 1 and the like.

[0038] Examples of the alkenyl group in the above substituent include a vinyl group, an allyl group, a 1-methylethenyl group, a 2-methylethenyl group, a 1-cyclohexenyl group, a 2-cyclohexenyl group, a 3-cyclohexenyl group, and the like, and R 1 and the like.

[0039] Examples of the alkenyloxy group in the above-mentioned substituent include an ethenyloxy group, a 2-propenyloxy group, a 1-methylethenyloxy group, a 2-methylethenyloxy group, a 1-cyclohexenyloxy group, a 2-cyclohexenyloxy group, and a 3-cyclohexenyloxy group, which are monovalent groups formed by bonding an oxygen atom to the above-mentioned alkenyl group.

[0040] The aryl group in the above-mentioned substituent may be either monocyclic or polycyclic, and preferably has 6 to 13 carbon atoms. Examples thereof include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-tolyl group, a m-tolyl group, a p-tolyl group, and a xylyl group (dimethylphenyl group). One or more hydrogen atoms of these aryl groups may be further substituted with one or more hydrogen atoms of these aryl groups or with one or more hydrogen atoms of the aryl groups described below. 1 Also included are those substituted with alkyl groups similar to those listed above. These substituted aryl groups preferably have 6 to 13 carbon atoms including the carbon number of the substituent.

[0041] The heteroaryl group in the above-mentioned substituent may be either monocyclic or polycyclic. Such a heteroaryl group may be, for example, the above-mentioned aryl group, in which one or more carbon atoms constituting the aromatic ring skeleton are substituted with heteroatoms, either singly or together with the hydrogen atoms bonded to those carbon atoms, and thus have aromaticity. Alternatively, it may be a cyclic unsaturated aliphatic hydrocarbon group having 3 or more carbon atoms, in which one or more carbon atoms constituting the ring skeleton are substituted with heteroatoms, either singly or together with the hydrogen atoms bonded to those carbon atoms, and thus have aromaticity. Preferred examples of such heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, selenium atoms, and phosphorus atoms. The number of heteroatoms constituting the aromatic ring skeleton is not particularly limited, but is preferably 1 to 2. When the number of heteroatoms constituting the aromatic ring skeleton is two or more, these multiple heteroatoms may be all the same, all different, or only partly the same.

[0042] In this specification, for example, a group having a structure in which an aromatic hydrocarbon group and an aromatic heterocyclic group are condensed is referred to as an aromatic heterocyclic group.

[0043] Examples of the aryloxy group in the above substituent include a phenoxy group, a 1-naphthoxy group, a 2-naphthoxy group, and other monovalent groups formed by bonding an oxygen atom to the above-mentioned aryl group.

[0044] Examples of the heteroaryloxy group in the above substituent include monovalent groups formed by bonding an oxygen atom to the above heteroaryl group.

[0045] The alkylsilyl group in the above substituent may be any of a monoalkylsilyl group, a dialkylsilyl group, and a trialkylsilyl group. In such an alkylsilyl group, the alkyl group bonded to the silicon atom may be any of a linear, branched, and cyclic group, and may have both a linear structure and a cyclic structure. The cyclic alkyl group may be either a monocyclic or a polycyclic group. Examples of the alkyl group bonded to the silicon atom include, for example, R 1 The alkyl group may be the same as the alkyl group in the above, and preferably has 1 to 10 carbon atoms.

[0046] In the dialkylsilyl group and trialkylsilyl group, the alkyl groups may be the same or different from one another. In the trialkylsilyl group, the three alkyl groups may all be the same or different, or only two may be the same.

[0047] Examples of the alkylsilyloxy group in the above-mentioned substituent include a monovalent group formed by bonding the above-mentioned alkylsilyl group to an oxygen atom, such as a dimethylsilyloxy group, an ethylmethylsilyloxy group, a trimethylsilyloxy group, an ethylmethyl-n-propylsilyloxy group, and an ethyldimethylsilyloxy group.

[0048] The number of substituents possessed by the aliphatic hydrocarbon group is not particularly limited, and may be one or more, or all hydrogen atoms may be substituted with substituents. The total number of carbon atoms, including the substituents, of the unsubstituted or substituted aliphatic hydrocarbon group may be one or more, preferably two or more. The total number of carbon atoms, including the substituents, is preferably 18 or less, more preferably 14 or less, and particularly preferably 12 or less. When the total number of carbon atoms, including the substituents, of the aliphatic hydrocarbon group is within the above range, film-forming ability and decomposability can be achieved at the same time.

[0049] In the above-described aliphatic hydrocarbon group, when the number of substituents is two or more, these substituents may be the same or different. That is, two or more substituents may all be the same, all may be different, or only some may be the same. Furthermore, the bonding position of the substituent in the above-described aliphatic hydrocarbon group is not particularly limited, but it is preferable that the terminal end of the substituent is the terminal end of the side chain, and it may be a carbon atom constituting the main chain in X or a carbon atom at the terminal of the side chain.

[0050] The unsubstituted or substituted aliphatic hydrocarbon group described above is preferably an unsubstituted or substituted alkylene group, and more preferably an unsubstituted or substituted ethylene group. When the aliphatic hydrocarbon group is such an alkylene group, particularly an ethylene group, the glass transition temperature (Tg) of the aliphatic polycarbonate is lowered, and low-temperature decomposition properties are improved.

[0051] The above aliphatic polycarbonate preferably has a structural unit represented by the following general formula (1a) (hereinafter sometimes abbreviated as "structural unit (1a)").

[0052] [ka] In the formula, R 1 , R 2 , R 3 and R4 are each independently a hydrogen atom, or an unsubstituted or substituted alkyl or alkoxy group, and R 1 , R 2 , R 3 and R 4 When two or more of the above are unsubstituted or substituted alkyl or alkoxy groups, these two or more alkyl or alkoxy groups may be bonded to each other to form a ring.

[0053] R in the formula 1 ~R 4 The alkyl group in may be linear, branched, or cyclic, and may have both a linear structure and a cyclic structure, but is preferably linear. The cyclic alkyl group may be monocyclic or polycyclic.

[0054] Examples of the linear or branched alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, a 2-methylpentyl group, an n-heptyl group, a 2-methylhexyl group, a 2-ethylhexyl group, an n-octyl group, an isooctyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, and a hexadecyl group.

[0055] Examples of the cyclic alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, an isobornyl group, a 1-adamantyl group, a 2-adamantyl group, and a tricyclodecyl group. Furthermore, examples of the cyclic alkyl group include those in which one or more hydrogen atoms of these cyclic alkyl groups are substituted with a linear, branched, or cyclic alkyl group. Here, examples of the linear, branched, and cyclic alkyl groups substituting hydrogen atoms include R 1 ~R 4 Examples of the alkyl group in the formula (I) include those exemplified above.

[0056] The linear alkyl group preferably has 2 or less carbon atoms, more preferably 1. When the number of carbon atoms in the alkyl group is within this upper limit, decomposability is improved. Furthermore, when the number of carbon atoms in the alkyl group is within this range, the aliphatic polycarbonate having the structural unit (1a) has a low glass transition temperature (Tg) and improved low-temperature decomposability.

[0057] R 1 ~R 4 The alkoxy group in may be linear, branched, or cyclic, and may have both a linear structure and a cyclic structure, but is preferably linear. The cyclic alkoxy group may be monocyclic or polycyclic.

[0058] Examples of the linear or branched alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, an n-pentyloxy group, an isopentyloxy group, an n-hexyloxy group, a 2-methylpentyloxy group, an n-heptyloxy group, a 2-methylhexyloxy group, a 2-ethylhexyloxy group, an n-octyloxy group, an isooctyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, a tridecyloxy group, a tetradecyloxy group, a pentadecyloxy group, and a hexadecyloxy group; 1 ~R 4 Examples of such groups include monovalent groups formed by bonding an oxygen atom to a linear or branched alkyl group as shown in the formula:

[0059] Examples of the cyclic alkoxy group include a cyclopropoxy group, a cyclobutoxy group, a cyclopentyloxy group, and a cyclohexyloxy group. 1 ~R 4 Examples of such groups include monovalent groups formed by bonding an oxygen atom to a cyclic alkyl group in the above formula.

[0060] The linear alkoxy group preferably has 2 or less carbon atoms, more preferably 1. When the number of carbon atoms in the alkoxy group is within this upper limit, decomposability is improved. Furthermore, when the number of carbon atoms in the alkoxy group is within this numerical range, the aliphatic polycarbonate having the structural unit (1a) has a low glass transition temperature (Tg) and improved low-temperature decomposability.

[0061] R 1 ~R 4 When two or more of the above are unsubstituted or substituted alkyl or alkoxy groups (hereinafter referred to as "alkyl groups, etc."), these two or more alkyl groups, etc. may be bonded to each other to form a ring together with the carbon atoms to which these alkyl groups, etc. are bonded. In this case, the position (carbon atom) at which these alkyl groups, etc. are bonded to each other is not particularly limited, but when an alkyl group, etc. having a substituent forms a ring, a carbon atom at a position other than the substituent is bonded to a carbon atom of the other alkyl group. A preferred example of the position (carbon atom) at which two or more alkyl groups, etc. are bonded to each other is the terminal carbon atom (carbon atom of a methyl group) of these alkyl groups, etc.

[0062] When two or more alkyl groups or the like are bonded to each other to form a ring, the ring may be either monocyclic or polycyclic, and preferably has 5 to 10 ring members.

[0063] R 1 ~R 4 Preferred examples of the structural unit (1a) in which two or more alkyl groups or the like form a ring include, for example, R 1 and R 2 Either one of these and R 3 and R 4 and either one of the following is bonded to each other to form a ring.

[0064] R 1 ~R 4When the alkyl group or alkoxy group in the formula (I) has a substituent, examples of the substituent include a hydroxy group, a carboxy group, a halogen atom, an alkoxy group, an alkenyl group, an alkenyloxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, an alkylsilyl group, an alkylsilyloxy group, and the like. These substituents are the same as the substituents when the aliphatic hydrocarbon group described above has a substituent.

[0065] R 1 ~R 4 The number of substituents that the alkyl or alkoxy group has in the formula (I) is not particularly limited, and may be 1 or 2 or more, or all hydrogen atoms may be substituted with substituents. The alkyl or alkoxy group having a substituent preferably has the number of carbon atoms, including the number of carbon atoms of the substituent, within the above-mentioned range.

[0066] R 1 ~R 4 When the alkyl group or alkoxy group in has two or more substituents, these substituents may be the same or different from one another. That is, the two or more substituents may all be the same, all be different, or only some may be the same.

[0067] The bonding position of the substituent in the alkyl group or alkoxy group is not particularly limited. For example, in the case of an alkyl group, it is preferably the terminal part (the carbon atom at the end of the alkyl group opposite to the carbon atom bonded to the ethylene group).

[0068] R with a substituent 1 ~R 4 Examples of the alkyl group having a substituent include a hydroxyalkyl group, a carboxyalkyl group, a haloalkyl group, an alkoxyalkyl group, an arylalkyl group, a heteroarylalkyl group, an aryloxyalkyl group, a heteroaryloxyalkyl group, an alkylsilylalkyl group, and an alkylsilyloxyalkyl group. 1 ~R 4When has a substituent, the hydrogen atom is similarly substituted with the substituent.

[0069] From the viewpoint of film-forming properties, the structural unit (1a) is R 1 ~R 4 may be an unsubstituted or substituted alkyl group or alkoxy group (alkyl group, etc.), but from the viewpoint of decomposability, the alkyl group, etc. is preferably R 1 ~R 4 is preferably 2 or less, more preferably 1 or less, and is 0 (R 1 ~R 4 are all hydrogen atoms).

[0070] In this embodiment, the aliphatic polycarbonate may have only one type of structural unit or two or more types, and when there are two or more types, the combination and ratio can be appropriately selected depending on the purpose. For example, when the aliphatic polycarbonate has the structural unit (1a), the aliphatic polycarbonate may or may not have a structural unit other than the structural unit (1a). The structural unit (1a) that the aliphatic polycarbonate has may be only one type or two or more types, and the structural unit other than the structural unit (1a) may be only one type or two or more types.

[0071] In the aliphatic polycarbonate of the present embodiment, the proportion of the amount of the structural unit (1a) relative to the total amount of structural units is preferably 90 mol% or more, more preferably 95 mol% or more, even more preferably 97 mol% or more, particularly preferably 99 mol% or more, and may be 100 mol%.

[0072] The aliphatic polycarbonate in this embodiment may have alkyl groups or the like in its side chains, but in order to obtain a particularly significant effect of facilitating thermal decomposition, the number of alkyl groups or the like in the side chains is preferably 2 or less, more preferably 1 or less, and particularly preferably 0 (no alkyl groups or the like in the side chains). However, in order to further lower the glass transition temperature (Tg) and further improve low-temperature decomposition properties, either or both of an alkyl group and an alkoxy group may be present in the side chains.

[0073] The number of carbon atoms in such alkyl and alkoxy groups is as explained above, and is preferably 2 or less, and particularly preferably 1. For example, when the aliphatic polycarbonate of this embodiment has the structural unit (1a), R 1 ~R 4 may be an alkyl group or an alkoxy group, and such an alkyl group or alkoxy group is 1 ~R 4 is preferably 2 or less, more preferably 1 or less, and is 0 (R 1 ~R 4 It is particularly preferred that R 1 ~R 4 When one or more of R is an alkyl group or an alkoxy group, the alkyl group or alkoxy group is preferably an alkyl group or alkoxy group having 2 or less carbon atoms, and the alkyl group or alkoxy group having 2 or less carbon atoms is preferably R 1 ~R 4 Among them, R 1 and / or R 2 It is more preferable that:

[0074] Specifically, the aliphatic polycarbonate of this embodiment is preferably polypropylene carbonate, a polypropylene carbonate derivative, polybutylene carbonate, or a polybutylene carbonate derivative. Degradable films using these polycarbonates can exhibit excellent degradability when prepared using the method of this embodiment.

[0075] (1-2) Physical properties of aliphatic polycarbonate The aliphatic polycarbonate used in this embodiment preferably has a weight-average molecular weight (Mw) of 2,000 or more, more preferably 10,000 or more, particularly preferably 20,000 or more, and even more preferably 40,000 or more. This results in good film-forming properties. Furthermore, the weight-average molecular weight (Mw) is preferably 1,000,000 or less, more preferably 700,000 or less, particularly preferably 400,000 or less, and even more preferably 200,000 or less. This results in good coatability. In this specification, unless otherwise specified, "weight-average molecular weight" refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0076] The aliphatic polycarbonate used in this embodiment preferably has a number average molecular weight (Mn) of 2,000 or more, more preferably 5,000 or more, particularly preferably 10,000 or more, and even more preferably 30,000 or more. This results in good film formability. Furthermore, the number average molecular weight (Mn) is preferably 500,000 or less, more preferably 400,000 or less, particularly preferably 300,000 or less, and even more preferably 150,000 or less. This results in good coatability. In this specification, unless otherwise specified, "number average molecular weight" refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0077] The glass transition temperature (Tg) of the aliphatic polycarbonate used in this embodiment is preferably 150°C or lower, more preferably 100°C or lower, particularly preferably 70°C or lower, and even more preferably 40°C or lower. This improves low-temperature decomposition properties. The glass transition temperature (Tg) is also preferably -40°C or higher, more preferably 0°C or higher, particularly preferably 10°C or higher, and even more preferably 15°C or higher. This improves the mechanical strength of the film. Note that a specific method for measuring the glass transition temperature (Tg) in this specification is as shown in the Examples below.

[0078] The content of the aliphatic polycarbonate in the degradable film of this embodiment is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 80% by mass or more, and even more preferably 90% by mass or more. This results in excellent degradability and reduces residue after the decomposition process. On the other hand, the content is preferably 99.999% by mass or less, more preferably 99.99% by mass or less, particularly preferably 99.9% by mass or less. This allows the amount of acid / base generator described below to be ensured.

[0079] (1-3) Method for producing aliphatic polycarbonate The aliphatic polycarbonate used in this embodiment can be produced, for example, by a production method including a step of polymerizing carbon dioxide (CO2) with a monomer that polymerizes to form an aliphatic main chain in the presence of a metal catalyst, while optionally controlling the water content below a predetermined level. For example, an aliphatic polycarbonate having structural unit (1a) can be produced by a production method including a step of polymerizing carbon dioxide with a compound represented by the following general formula (1b) (ethylene oxide (epoxide) or its derivative, hereinafter sometimes abbreviated as "compound (1b)") in the presence of a metal catalyst, while optionally controlling the water content below a predetermined level (see, for example, International Publication No. 2011 / 142259). In this specification, unless otherwise specified, the term "monomer" refers to a compound that polymerizes with carbon dioxide to form an aliphatic main chain. Furthermore, the term "derivative" refers to a compound in which one or more hydrogen atoms of the original compound are substituted with a group (substituent) other than a hydrogen atom. The "substituent" here refers to the R 1 ~R 4 When the group has a substituent, the substituents are the same as those of the group.

[0080] [ka] (In the formula, R 1 , R 2 , R 3 and R 4 is the same as above; and n is an integer of 2 or greater.

[0081] In the formula, R 1 ~R 4 represents R in the general formula (1a) 1 ~R 4 In addition, n is an integer of 2 or more, and represents the number of structural units (1a) in the aliphatic polycarbonate.

[0082] Preferred examples of compound (1b) include ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide, 1-pentene oxide, 1-hexene oxide, 1-octene oxide, 1-decene oxide, cyclopentene oxide, styrene oxide, vinylcyclohexene oxide, 3-phenylpropylene oxide, 3,3,3-trifluoropropylene oxide, 3-naphthylpropylene oxide, butadiene monoxide, 3-vinyloxypropylene oxide, 3-trimethylsilyloxypropylene oxide, 3-methoxypropylene oxide (methyl glycidyl ether), 3-n-butoxypropylene oxide (n-butyl glycidyl ether), glycidyl acrylate, and glycidyl methacrylate. Among these, ethylene oxide, derivatives of ethylene oxide, propylene oxide, derivatives of propylene oxide, 1-butene oxide and derivatives of 1-butene oxide are more preferred as compound (1b) in terms of having high polymerization reactivity with carbon dioxide.

[0083] The monomer used in the polymerization reaction step (e.g., compound (1b) or a monomer other than compound (1b)) may be one type or two or more types, and when two or more types are used, the combination and ratio thereof may be appropriately adjusted depending on the purpose.

[0084] Examples of the metal catalyst used in the polymerization reaction step include a cobalt catalyst, an aluminum catalyst, a zinc catalyst, etc. Among these, the metal catalyst is preferably a cobalt catalyst, and particularly preferably a cobalt salen catalyst, because it exhibits high polymerization activity in the polymerization reaction of carbon dioxide with the above-mentioned monomer.

[0085] The amount of metal catalyst used during the polymerization reaction is preferably 0.001 to 20 parts by mass, and particularly preferably 0.01 to 14 parts by mass, per 100 parts by mass of the monomer used, which allows the polymerization reaction to proceed more easily.

[0086] In the polymerization reaction step, it is also preferable to use a co-catalyst together with the metal catalyst, such as bis(triphenylphosphoranylidene)ammonium chloride, 4-dimethylaminopyridine, tetrabutylammonium chloride, tetrabutylammonium bromide, triphenylphosphine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, or 1,4-diazabicyclo[2.2.2]octane.

[0087] The amount of the co-catalyst used during the polymerization reaction is preferably 0.001 to 20 parts by mass, and particularly preferably 0.01 to 14 parts by mass, per 100 parts by mass of the monomer used, which allows the polymerization reaction to proceed more easily.

[0088] The method for carrying out the polymerization reaction is not particularly limited as long as the target product can be obtained. For example, an autoclave may be charged with the above-mentioned monomer, metal catalyst, co-catalyst, and, if necessary, a solvent, and then the resulting mixture is mixed with carbon dioxide under pressure to cause the reaction.

[0089] The solvent used in the polymerization reaction as needed is not particularly limited, but is preferably an organic solvent. Examples of the organic solvent include aliphatic hydrocarbons such as pentane, hexane, octane, decane, and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated hydrocarbons such as chloromethane, dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, chlorobenzene, and bromobenzene; carboxylic acid esters such as ethyl acetate, propyl acetate, butyl acetate, and isobutyl acetate; carbonate esters such as dimethyl carbonate, diethyl carbonate, propylene carbonate, and 1,2-butylene carbonate; and lactams such as N-methylpyrrolidone.

[0090] The amount of solvent used is preferably 100 to 10,000 parts by mass per 100 parts by mass of the monomer used, since this allows the polymerization reaction to proceed more easily.

[0091] The pressure at which carbon dioxide is injected during the polymerization reaction is not particularly limited, but is preferably 0.1 to 20 MPa, more preferably 0.1 to 10 MPa, and even more preferably 0.1 to 5 MPa. When the pressure at which carbon dioxide is injected is equal to or greater than the above-mentioned lower limit, the polymerization reaction proceeds more easily. Furthermore, when the pressure at which carbon dioxide is injected is equal to or less than the above-mentioned upper limit, excessive use of carbon dioxide is suppressed, improving economic efficiency.

[0092] During the polymerization reaction, the amount of water in the reaction system is preferably 5 mol% or less, more preferably 4.5 mol% or less, based on the amount (mol) of metal catalyst used. The amount of water in the reaction system during the polymerization reaction can be measured, for example, using a Karl Fischer moisture meter. The amount of water in the reaction system can be adjusted by known methods, for example, using a desiccant.

[0093] The reaction temperature during the polymerization reaction is not particularly limited, but is preferably 20°C or higher, and more preferably 40°C or higher. Furthermore, the reaction temperature during the polymerization reaction is preferably 100°C or lower, and more preferably 80°C or lower. By keeping the reaction temperature at or above the lower limit, the polymerization reaction is completed in a shorter time. By keeping the reaction temperature at or below the upper limit, side reactions are suppressed, and the yield of the aliphatic polycarbonate is improved.

[0094] The reaction time for the polymerization reaction may be adjusted appropriately depending on the reaction temperature, but is preferably 2 to 40 hours.

[0095] After the polymerization reaction is completed, known post-treatments may be carried out as necessary, and the target aliphatic polycarbonate may be isolated by known methods. The resulting aliphatic polycarbonate may also be purified as necessary.

[0096] Carbon dioxide is a substance that causes global warming, but at the same time, it is emitted daily in various industrial sectors, and there is a need to reduce emissions on a global scale. In contrast, the above-mentioned production method uses carbon dioxide as a raw material, so it can fix carbon dioxide and is therefore excellent in terms of expanding the options for carbon resources.

[0097] The degradable film of the present embodiment may contain only one type of aliphatic polycarbonate, or two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily depending on the purpose.

[0098] (2) Acid-base generator The acid / base generator used in this embodiment generates an acid or a base upon irradiation with energy rays. Energy rays refer to electromagnetic waves or charged particle rays that have an energy quantum, and specific examples include ultraviolet rays, electron beams, and X-rays. As will be described later, ultraviolet rays, which are easy to handle, are preferred as the energy rays irradiated onto the photodegradable film according to this embodiment. In other words, the acid / base generator used in this embodiment is preferably one that generates an acid or a base upon irradiation with ultraviolet rays.

[0099] Examples of base generators that generate a base upon irradiation with energy rays include α-aminoacetophenone compounds, oxime ester compounds, and compounds having a substituent such as an acyloxyimino group, an N-formylated aromatic amino group, an N-acylated aromatic amino group, a nitrobenzyl carbamate group, or an alkoxybenzyl carbamate group. As the α-aminoacetophenone compound, those having two or more nitrogen atoms are particularly preferred.

[0100] Examples of base generators include 9-anthramethyl-N,N'-diethylcarbamate, (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine, 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidinium 2-(3-benzoylphenyl)propionate, and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate.

[0101] As a base generator, it has a biguanide salt structure and a molar absorption coefficient of 50M for energy rays with a wavelength of 365 nm, which can promote the decomposition of aliphatic polycarbonate even with a small amount added. -1 cm -1 Preferably, it is 60M or more. -1 cm -1 More preferably, 70M or more -1 cm -1 Examples of such a base generator include 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium 2-(3-benzoylphenyl)propionate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate, and the like.

[0102] The above base generators can be used alone or in combination of two or more.

[0103] On the other hand, the acid generator that generates an acid upon irradiation with energy rays is not particularly limited, and examples thereof include naphthoquinone diazide compounds, sulfonium salts, iodonium salts, diazonium salts, selenium salts, pyridinium salts, ferrocenium salts, phosphonium salts, and onium salts such as thiopyrnium salts, and more preferably aromatic sulfonium salts and aromatic iodonium salts. In addition, the anion component may be BF4 - , PF6 - , AsF6 - , SbF6 - , and B(C6F5)4 - Particularly preferred is B(C6F5)4- , SbF6 - , and PF3(C2F5)3 - Examples include:

[0104] As an acid generator, it has a sulfonium salt structure and a molar absorption coefficient of 50M for energy rays with a wavelength of 365 nm, which can promote the decomposition of aliphatic polycarbonate even with a small amount added. -1 cm -1 Preferably, it is 70M or more. -1 cm -1 More preferably, 150M or more -1 cm -1 More preferably, it is 300M or more. -1 cm -1 Examples of such acid generators include [1,1'-biphenyl]-4-yl[4-[[1,1'-biphenyl]-4-ylthio]phenyl](phenyl)sulfonium tetrakis(perfluorophenyl)borate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium hexafluoroarsinate.

[0105] The above acid generators can be used alone or in combination of two or more.

[0106] From the viewpoint of preventing corrosion of the adherend, a base generator is preferable to an acid generator.

[0107] The content of the acid / base generator in the degradable film of this embodiment is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, particularly preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of the aliphatic polycarbonate. This allows the acid / base generator to exert its effect well, and the degradable film can be decomposed well in the heating step and decomposition step. Furthermore, the content is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, particularly preferably 6 parts by mass or less, and even more preferably 5 parts by mass or less. This allows the residue after the decomposition step to be reduced.

[0108] (3) Other ingredients In addition to the above components, the degradable film of the present embodiment may contain various additives, such as sensitizers, plasticizers, crosslinking agents, antistatic agents, thickeners, viscosity reducers, thermal conductive agents, pigments, lightweight fillers, antioxidants, rust inhibitors, etc., as long as they do not impair the desired degradability. However, it is preferable that the film does not contain any components that will become residues after the decomposition step.

[0109] 1-2. Manufacturing method of degradable film (1) Preparation of degradable film-forming composition To produce the degradable film of this embodiment, an aliphatic polycarbonate, an acid / base generator, and optional additives are mixed in a solvent to obtain a coating solution of a degradable film-forming composition. Note that if any of the above components is solid or if precipitation occurs when mixed with other components in an undiluted state, that component may be dissolved or diluted in a solvent before being mixed with the other components.

[0110] Examples of the solvent that can be used include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; alcohols such as methanol, ethanol, and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate, propyl acetate, butyl acetate, and isobutyl acetate; ethers such as diethylene glycol dimethyl ether; cellosolve-based solvents such as ethyl cellosolve; carbonate esters such as propylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, and diethyl carbonate; and lactam-based solvents such as N-methylpyrrolidone.

[0111] The concentration and viscosity of the coating solution of the degradable film-forming composition prepared in this manner are not particularly limited as long as they are within a range that allows coating, and can be selected appropriately depending on the situation. For example, the degradable film-forming composition is diluted with a solvent so that the concentration becomes 10 to 60 mass %. Note that the addition of a dilution solvent is not a necessary condition for obtaining the coating solution, and as long as the degradable film-forming composition has a viscosity that allows coating, the addition of a dilution solvent is not necessary.

[0112] (2) Coating and drying of the degradable film-forming composition The coating solution of the degradable film-forming composition obtained as described above is applied to a desired object and then dried to obtain a degradable film.

[0113] The coating film of the degradable film-forming composition can be dried by heat treatment. The heating temperature for the heat treatment is preferably 50 to 150° C., and more preferably 70 to 120° C. The heating time is preferably 10 seconds to 10 minutes, and more preferably 50 seconds to 2 minutes.

[0114] The object to be coated may be a release sheet, a desired substrate, a desired thin film (film to be etched), or the like, and is not particularly limited thereto. For example, a coating solution of the degradable film-forming composition may be applied to the release surface of a release sheet, dried, and then laminated with the desired substrate to obtain a laminate consisting of release sheet / degradable film / substrate. Alternatively, a coating solution of the degradable film-forming composition may be applied to the release surface of a first release sheet, dried, and then laminated with the release surface of a second release sheet to obtain a laminate consisting of first release sheet / degradable film / second release sheet. On the other hand, when a degradable film is used in photolithography, it may be directly coated on, for example, a metal thin film formed on a substrate or an oxide film formed on a semiconductor wafer, and a degradable film may be formed on these thin films.

[0115] Examples of methods for applying the coating solution of the degradable film-forming composition include bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, curtain coating, spray coating, and spin coating.

[0116] 1-3. Thickness of degradable film The thickness of the degradable film in this embodiment is preferably 1 μm or more, more preferably 3 μm or more, particularly preferably 5 μm or more, and even more preferably 10 μm or more. This allows the film to maintain good strength. Furthermore, for example, it can function as a resist pattern. On the other hand, the thickness is preferably 50 μm or less, more preferably 40 μm or less, particularly preferably 30 μm or less, and even more preferably 25 μm or less. This allows the degradable film to be decomposed well in the decomposition step described below.

[0117] 2.Irradiation process In this embodiment, next, the entire surface or a part of the decomposable film in plan view is irradiated with energy rays. This irradiation of energy rays may be performed at the same timing as the heating in the decomposition step described below. That is, the irradiation step and the decomposition step may be performed simultaneously. However, if the acid / base generator is likely to volatilize due to heating in the decomposition step, it is preferable to perform the irradiation step before the decomposition step.

[0118] When the decomposable film is irradiated with energy rays, an acid or base is generated from the acid / base generator. The action of the acid or base makes the aliphatic polycarbonate more susceptible to thermal decomposition in the subsequent decomposition step.

[0119] As mentioned above, examples of energy rays include ultraviolet rays, electron beams, and X-rays, among which ultraviolet rays are preferred because they are easy to handle and irradiation equipment can be easily installed.The wavelength of ultraviolet rays is generally 10 to 400 nm.

[0120] The energy rays irradiated in this embodiment preferably include energy rays (ultraviolet rays) with at least a portion of the wavelength range of 150 to 400 nm. This makes it easier for an acid or base to be generated from the acid / base generator. The wavelength is preferably 190 to 380 nm, and particularly preferably 240 to 370 nm.

[0121] The light amount (total light amount) of the energy rays (ultraviolet rays) irradiated in this embodiment is 50 to 1500 mJ / cm 2 It is preferable that the concentration is 80 to 1200 mJ / cm. 2 and more preferably 100 to 1100 mJ / cm 2 This makes it easier for the acid or base to be generated from the acid / base generator.

[0122] The irradiance of the energy rays (ultraviolet rays) irradiated in this embodiment is usually 50 to 500 mW / cm 2 Approximately 100-450mW / cm 2 is preferred, and 150 to 300 mW / cm 2The ultraviolet light source is not particularly limited, and examples thereof include a high-pressure mercury lamp, a metal halide lamp, and a UV-LED.

[0123] When an electron beam is used as the energy beam, the acceleration voltage can be appropriately selected depending on the type and amount of the acid / base generator and the thickness of the decomposable film. An acceleration voltage of approximately 10 to 1,000 kV is generally preferred. The irradiation dose can be set within a range that allows the acid or base to be appropriately generated from the acid / base generator, and is generally selected within a range of 10 to 1,000 krad. There are no particular limitations on the electron beam source, and various electron beam accelerators, such as Cockcroft-Walton, Van de Graaf, resonant transformer, insulated core transformer, linear, dynamitron, and high-frequency types, can be used.

[0124] In this embodiment, depending on the application of the degradable film, the energy beam may be irradiated onto the entire surface of the degradable film, or onto a portion of the degradable film in a planar view. When irradiating a portion of the degradable film in a planar view with the energy beam, the energy beam is irradiated onto the portion of the degradable film that is to be decomposed. When it is desired to decompose the degradable film in a desired pattern, it is preferable to irradiate the degradable film with the energy beam using a mask having a pattern that is the inverse of the desired pattern. This makes it possible to decompose the desired portion of the degradable film. As the mask, a known mask can be used, and there are no particular limitations as long as it is made of a material that does not transmit energy beams.

[0125] As a method for irradiating the portion of the degradable film to be decomposed with energy rays, a UV laser can be used without using a mask to irradiate the desired portion with UV laser light.

[0126] 3. Decomposition process In this embodiment, the decomposable film is finally heated to decompose the entire surface or a portion of the decomposable film in plan view. In the irradiation step described above, the aliphatic polycarbonate is susceptible to thermal decomposition due to the action of the acid or base generated from the acid / base generator. Therefore, the aliphatic polycarbonate is thermally decomposed by the heating, thereby decomposing the decomposable film. Contamination by residues is suppressed if the decomposable film does not substantially contain any components other than the aliphatic polycarbonate and the acid / base generator.

[0127] The heating temperature is preferably 30°C or higher, more preferably 40°C or higher, particularly preferably 50°C or higher, and even more preferably 55°C or higher. This allows the aliphatic polycarbonate to be thermally decomposed well, thereby allowing the decomposable film to be decomposed well. The heating temperature is also preferably 150°C or lower, more preferably 120°C or lower, particularly preferably 110°C or lower, and even more preferably 105°C or lower. As described above, in this embodiment, the aliphatic polycarbonate can be decomposed even at a relatively low temperature, and therefore the decomposable film can be decomposed even at the above-mentioned relatively low temperature.

[0128] The heating time is preferably 1 to 30 minutes, more preferably 2 to 27 minutes, particularly preferably 3 to 25 minutes, and even more preferably 4 to 20 minutes, which allows the decomposable film to be decomposed satisfactorily.

[0129] The heating means is not particularly limited and may be appropriately selected depending on the intended use of the degradable film. For example, a hot air dryer, a near-infrared lamp, a hot plate, or other suitable means may be used.

[0130] 4.Applications Examples of the methods for using the degradable film according to the embodiment include a method for producing a resist pattern, use as a temporary fixing material (agent), use as an easily degradable adhesive, and the like.

[0131] [Method for producing a resist pattern] A method for producing a resist pattern according to one embodiment of the present invention includes the steps of: preparing a decomposable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; irradiating a portion of the decomposable film in a planar view with energy rays; and decomposing the portion of the decomposable film in a planar view by heating the decomposable film.

[0132] The decomposable film used is as described in the above embodiment. In the irradiation step, a mask having a desired pattern can be used to irradiate a portion of the decomposable film in a planar view with energy rays. Alternatively, a portion of the decomposable film in a planar view can be irradiated with UV laser light.

[0133] The details of the irradiation step and the decomposition step are as described in the above-described embodiment. According to the method for producing a resist pattern of this embodiment, a resist film (resist pattern) having a desired pattern can be produced on a metal thin film formed on a substrate or an oxide film formed on a semiconductor wafer, and can be used for photolithography.

[0134] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0135] In this specification, when it is written "X to Y" (X and Y are any numbers), it means "X or more and Y or less" unless otherwise specified, and also includes the meaning "preferably greater than X" or "preferably smaller than Y." Furthermore, when it is written "X or more" (X is any number), it means "preferably greater than X" unless otherwise specified, and when it is written "Y or less" (Y is any number), it also means "preferably smaller than Y" unless otherwise specified. [Example]

[0136] The present invention will be described in more detail below by showing examples, but the present invention is not limited to the following examples.

[0137] [Production Example 1] (Synthesis of polymerization catalyst) (R,R)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexanecobalt(II) and pentafluorobenzoic acid were weighed out in a molar ratio of 1:1.1 and placed in a flask, followed by the addition of dehydrated toluene. The flask was shielded from light with aluminum foil and the reaction was carried out at room temperature for 20 hours. The chemical reaction formula is as follows: After the reaction was completed, the solvent was removed under reduced pressure and the mixture was washed several times with excess hexane. The mixture was then vacuum dried at room temperature to obtain a cobalt salen complex.

[0138] [ka]

[0139] (Preparation of Aliphatic Polycarbonate (PPC)) 1,437 parts by mass of propylene oxide as a raw material monomer, 10.1 parts by mass of the cobalt salen complex obtained above as a catalyst, and 7.1 parts by mass of bis(triphenylphosphoranylidene)ammonium chloride as a co-catalyst were dissolved in 479 parts by mass of ethyl acetate to obtain a mixed liquid.

[0140] The interior of a 4-liter autoclave equipped with a stirrer, gas inlet tube, and thermometer was first purged with nitrogen, and then the mixture was charged. Next, while stirring the resulting mixture, carbon dioxide gas was added until the reaction system reached 3 MPa. The temperature was then raised to 40°C, and the polymerization reaction was carried out for 5 hours while replenishment of carbon dioxide consumed during the reaction was continued. After the reaction was completed, the autoclave was cooled and depressurized, and the contents were diluted with ethyl acetate. The catalyst was then removed by reprecipitation purification.

[0141] The obtained ethyl acetate solution was dried to obtain the produced aliphatic polycarbonate. Analysis showed that the glass transition temperature (Tg) was 30 °C, the weight average molecular weight (Mw) was 43,900, and the number average molecular weight (Mn) was 35,700. This aliphatic polycarbonate was polypropylene carbonate (PPC).

[0142] 〔Production Example 2〕Preparation of aliphatic polycarbonate (PBC) An aliphatic polycarbonate was prepared in the same manner as in Example 1, except that 1,2-butylene oxide was used instead of propylene oxide as the raw material monomer. The produced aliphatic polycarbonate was obtained and analyzed. As a result, the glass transition temperature (Tg) was 16 °C, the weight average molecular weight (Mw) was 59,000, and the number average molecular weight (Mn) was 47,000. This aliphatic polycarbonate was polybutylene carbonate (PBC).

[0143] Here, the glass transition temperature (Tg) described in the production example was determined by differential scanning calorimetry (DSC) using a product named "DSC Q2000" manufactured by TA Instruments Japan Co., Ltd. Specifically, an aluminum pan was used as the container, and the temperature was raised from -70 °C to 150 °C at 10.0 °C / min under a nitrogen atmosphere, held for 5 minutes, then cooled to -70 °C at 10.0 °C / min, held for 5 minutes, and then raised to 150 °C at 10.0 °C / min for measurement.

[0144] Also, the weight average molecular weight (Mw) and number average molecular weight (Mn) described in the production example were measured using a gel permeation chromatograph (product name "HLC-8320" manufactured by Tosoh Corporation) under the following conditions and were values measured in terms of standard polystyrene conversion.

[0145] <GPC measurement conditions> · Column: A series of columns connected in sequence, namely "TSK guard column SuperH-H", "TSK gel SuperHM-H", "TSK gel SuperHM-H", and "TSK gel SuperH2000" (all manufactured by Tosoh Corporation) Column temperature: 40℃ Developing solvent: tetrahydrofuran (copolymer concentration 1% by mass) ·Injection volume: 20μl ·Flow rate: 0.6mL / min Detector: Differential refractometer Standard sample: Polystyrene

[0146] Example 1 1. Manufacturing of degradable films 10 parts by mass of polypropylene carbonate obtained in Production Example 1 and 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium 2-(3-benzoylphenyl)propionate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "WPBG-266", molar absorption coefficient for energy rays with a wavelength of 365 nm: 80 M -1 cm -1 0.5 parts by mass of the above was dissolved in 40 parts by mass of methyl ethyl ketone, and the resulting mixture was thoroughly stirred and mixed to prepare a coating liquid of the film-forming composition.

[0147] The obtained coating solution of the film-forming composition was applied using a knife coater to the release-treated surface of a heavy-release release sheet (manufactured by Lintec Corporation, product name "SP-PET382150", thickness: 38 μm) in which one side of a polyethylene terephthalate film had been treated with a silicone-based release agent, and then heated and dried at 100°C for 2 minutes to form a film.

[0148] Next, the release-treated surface of a light-release release sheet (manufactured by Lintec Corporation, product name "SP-PET381031", thickness: 38 μm), which was a polyethylene terephthalate film with one side treated with a silicone-based release agent, was laminated onto the above film. In this way, a laminate consisting of a light-release release sheet / degradable film (20 μm) / heavy-release release sheet was produced. The thickness of the resulting degradable film was 20 μm.

[0149] 2.Irradiation process The light release sheet was peeled off from the laminate, and the exposed degradable film was attached to a silicon plate. Next, the heavy release sheet was peeled off from the degradable film. Then, a high-pressure mercury lamp was used to irradiate the degradable film on the silicon plate with an illuminance of 200 mW / cm. 2 ,Light amount: 1000mJ / cm 2 The central wavelength of the irradiated ultraviolet light was 365 nm.

[0150] 3. Decomposition process Next, the laminate of the UV-irradiated degradable film and silicon plate was heated at 60°C for 5, 10, 15 or 20 minutes in a laboratory oven (Espec Corporation, "SPH-202") to decompose the degradable film.

[0151] Examples 2 and 3 The same degradable film as in Example 1 was decomposed in the same manner as in Example 1, except that the heating temperature in the decomposition step was changed to the temperature shown in Table 1.

[0152] Example 4 A degradable film was produced in the same manner as in Example 1, except that the polybutylene carbonate prepared in Production Example 2 was used instead of the polypropylene carbonate prepared in Production Example 1. Then, after carrying out the irradiation step in the same manner as in Example 1, the decomposition step was carried out in the same manner as in Example 1, except that the heating temperature in the decomposition step was changed to 40°C.

[0153] Examples 5 to 7 The same degradable film as in Example 4 was decomposed in the same manner as in Example 4, except that the heating temperature in the decomposition step was changed to the temperature shown in Table 1.

[0154] Comparative Examples 1 to 4 An acrylic adhesive (product name "PE-121" manufactured by Nippon Carbide Industries Co., Ltd.) was used in place of the polypropylene carbonate prepared in Production Example 1, and a laminate was produced in the same manner as in Example 1. Specifically, a laminate consisting of a light release type release sheet / adhesive layer (20 μm) / heavy release type release sheet was produced.

[0155] The light release release sheet was peeled off from the laminate, and the exposed adhesive layer was attached to a silicon plate. Next, the heavy release release sheet was peeled off from the adhesive layer. The adhesive layer on the silicon plate was then subjected to an irradiation step in the same manner as in Example 1. Thereafter, a decomposition step was carried out at the temperature shown in Table 1 in the same manner as in Example 1.

[0156] [Test Example 1] In the decomposition process of the Examples and Comparative Examples, the films were heated for 5, 10, 15, and 20 minutes, then allowed to cool, and the thicknesses of the decomposable film and the pressure-sensitive adhesive layer were measured in accordance with JIS K7130:1999 using a constant pressure thickness measuring device (manufactured by Teclock Corporation, product name "PG-02").

[0157] Then, the reduction rate (film thickness reduction rate; %) relative to the thickness before the irradiation step was calculated according to the following formula. Film thickness reduction rate (%) = {(thickness before irradiation process - measured thickness) / thickness before irradiation process} × 100

[0158] The degradability of the degradable film and the adhesive layer was then evaluated based on the following criteria. The results are shown in Table 1. A: The film thickness reduction rate was 90% or more. B: The film thickness reduction rate was 60% or more and less than 90%. C: The film thickness reduction rate was 10% or more and less than 60%. F: The film thickness reduction rate was less than 10%.

[0159] In each example, the same test as above was also carried out when the irradiation step was not carried out (no UV irradiation). The results are shown in Table 1.

[0160] [Table 1]

[0161] As can be seen from Table 1, by using the degradable films produced in the Examples and carrying out the steps of the Examples, the degradable films could be effectively decomposed. [Industrial Applicability]

[0162] The method for using the decomposable film according to the present invention is suitable for, for example, producing a resist pattern.

Claims

1. a step of preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays, the film having a content of adhesive resins other than the aliphatic polycarbonate of 10% by mass or less; an irradiation step of irradiating the entire surface or a part of the degradable film in a plan view with energy rays; a decomposition step of heating the decomposable film to decompose the entire surface or a part of the decomposable film in plan view; Equipped with the acid / base generator is an acid generator that generates an acid upon irradiation with energy rays, The acid generator has a sulfonium salt structure and a molar absorption coefficient of 50 M −1 cm −1 or more with respect to an energy ray having a wavelength of 365 nm. A method for using a degradable film.

2. A process for preparing a degradable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays, the film having a content of adhesive resins other than the aliphatic polycarbonate of 10 mass % or less; an irradiation step of irradiating the entire surface or a part of the degradable film in a plan view with energy rays; a decomposition step of heating the decomposable film to decompose the entire surface or a part of the decomposable film in plan view; Equipped with the acid / base generator is a base generator that generates a base upon irradiation with energy rays, The base generator has a biguanide salt structure and a molar absorption coefficient of 50 M −1 cm −1 or more with respect to an energy ray having a wavelength of 365 nm. A method for using a degradable film.

3. a step of preparing a decomposable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; an irradiation step of irradiating the entire surface or a part of the degradable film in a plan view with energy rays; a decomposition step of heating the decomposable film at 30°C or higher and 120°C or lower to decompose the entire surface or a part of the decomposable film in plan view; Equipped with the acid / base generator is an acid generator that generates an acid upon irradiation with energy rays, The acid generator has a sulfonium salt structure and a molar absorption coefficient of 50 M −1 cm −1 or more with respect to an energy ray having a wavelength of 365 nm. A method for using a degradable film.

4. A method of producing a decomposable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; an irradiation step of irradiating the entire surface or a part of the degradable film in a plan view with energy rays; a decomposition step of heating the decomposable film at 30°C or higher and 120°C or lower to decompose the entire surface or a part of the decomposable film in plan view; Equipped with the acid / base generator is a base generator that generates a base upon irradiation with energy rays, The base generator has a biguanide salt structure and a molar absorption coefficient of 50 M −1 cm −1 or more with respect to an energy ray having a wavelength of 365 nm. A method for using a degradable film.

5. 5. The method for using the degradable film according to claim 1, wherein the energy rays irradiated in the irradiation step include energy rays having at least a part of a wavelength range of 150 to 400 nm.

6. The amount of light of the energy ray irradiated in the irradiation step is 50 mJ / cm ２ Above, 1500mJ / cm ２ A method for using the degradable film according to any one of claims 1 to 4, characterized in that:

7. 5. The method for using the degradable film according to claim 1, wherein the heating time in the decomposition step is 1 minute or more and 30 minutes or less.

8. The method for using the degradable film according to any one of claims 1 to 4, characterized in that the degradable film contains the acid / base generator in an amount of 0.01 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the aliphatic polycarbonate.

9. 5. The method for using the degradable film according to claim 1, wherein the aliphatic polycarbonate has a structural unit represented by the following general formula (1a): 【Chemistry 1】 (In the formula, R １ , R ２ , R ３ and R ４ each independently represents a hydrogen atom, a linear hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 8 carbon atoms, or an aromatic hydrocarbon group having 6 to 8 carbon atoms.

10. 5. The method for using the degradable film according to claim 1, wherein the aliphatic polycarbonate has a glass transition temperature of -40°C or higher and 150°C or lower.

11. 5. The method for using the degradable film according to claim 1, wherein the aliphatic polycarbonate has a weight average molecular weight of 2,000 or more and 1,000,000 or less.

12. 5. The method for using the degradable film according to claim 1, wherein the thickness of the degradable film is 1 μm or more and 50 μm or less.

13. a step of preparing a decomposable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; an irradiation step of irradiating a part of the degradable film in a planar view with an energy ray; a decomposition step of heating the decomposable film to decompose a part of the decomposable film in a planar view; Equipped with the acid / base generator is an acid generator that generates an acid upon irradiation with energy rays, The acid generator has a sulfonium salt structure and a molar absorption coefficient of 50 M −1 cm −1 or more with respect to an energy ray having a wavelength of 365 nm. A method for producing a resist pattern comprising:

14. A method of producing a decomposable film comprising: preparing a decomposable film containing an aliphatic polycarbonate and an acid / base generator that generates an acid or a base upon irradiation with energy rays; an irradiation step of irradiating a part of the degradable film in a planar view with an energy ray; a decomposition step of heating the decomposable film to decompose a part of the decomposable film in a planar view; Equipped with the acid / base generator is a base generator that generates a base upon irradiation with energy rays, The base generator has a biguanide salt structure and a molar absorption coefficient of 50 M −1 cm −1 or more with respect to an energy ray having a wavelength of 365 nm. A method for producing a resist pattern comprising:

Images