Pattern inverting photocurable composition, and method for producing electronic device or optical device using same

Abstract

Provided is a pattern inverting photocurable composition that accurately transfers a pattern of a first resist film while inhibiting deformation of the pattern to form a second resist film having a relief-inverted pattern of the first resist film and having etching resistance.　A pattern inverting photocurable composition according to the present invention uses, as a mold, a pattern of a first resist film having a pattern provided in the surface of a member to be processed, to form, on the surface of the member to be processed, a second resist film having a relief-inverted pattern of the pattern of the first resist film. The photocurable composition comprises: a photoacid generator; and an aromatic monomer having a vinyl group and an electron-donating group other than the vinyl group and having a molecular weight of at least 120. The photocurable composition has a viscosity of 0.1-15 mPa·s at 25°C and at a shear rate of 200 (s-1).

Description

Photocurable composition for pattern reversal and method for manufacturing electronic or optical device using same

[0001] The present invention relates to a photocurable composition for pattern reversal and a method for producing an electronic device or an optical device using the same.

[0002] In recent years, as electronic devices have become larger in capacity and smaller in size, the circuit patterns of semiconductor integrated circuits have become increasingly finer.

[0003] The circuit pattern of a semiconductor integrated circuit is formed by etching a substrate while the substrate is covered with a mask having a pattern and having etching resistance (i.e., an etching mask). In order to miniaturize the circuit pattern of a semiconductor integrated circuit, it is necessary to miniaturize the pattern of the etching mask.

[0004] In the field of optical devices, research into new technologies such as metalenses and silicon photonics is actively underway. For example, metalenses requires a processing technology that can easily and cost-effectively form surface nanostructures. Similarly, silicon photonics requires a processing technology that can easily and cost-effectively form thin-wire waveguides.

[0005] Surface nanostructures of optical devices and patterns of thin-line waveguides can be formed by etching a substrate covered with an etching mask, similar to the circuit patterns of semiconductor integrated circuits.

[0006] As a method for forming an etching mask, for example, an imprint method is known.

[0007] When forming an etching mask by an imprint method, as patterns become finer, it becomes very difficult to release the pattern, particularly in patterns with a high aspect ratio such as line patterns or dot patterns, and the pattern is likely to be damaged during release.

[0008] Therefore, a method is known in which a first resist film having a pattern with a low aspect ratio that is easy to release is first formed by an imprinting method, the pattern shape of the formed first resist film is transferred to a resin composition for pattern reversal, and then the first resist film is removed by etching, thereby producing a second resist film having a high aspect ratio pattern that is an inverse of the concavo-convex shape of the first resist film.

[0009] For example, Patent Document 1 discloses a method in which a composition containing 3,000 to 3,500 parts by weight of a solvent such as PGMEA per 100 parts by weight of an aromatic polymer (specifically, a polymer obtained by polymerizing an aromatic monomer such as styrene, vinylnaphthalene, or N-vinylcarbazole) is used as a pattern reversal resin composition, which is applied onto a first resist film and prebaked at 100°C or 180°C for 60 seconds to evaporate the solvent, thereby transferring the pattern shape of the first resist film to the composition.

[0010] JP 2014-157246 A

[0011] However, when the pattern reversal resin composition applied to the first resist film is subjected to a pre-bake treatment to evaporate the solvent, the heat of the pre-bake easily causes the pattern of the first resist film to collapse, which in turn narrows the width of the concave portions of the pattern of the second resist film obtained by reversing the concave and convex portions of the pattern, reduces the flatness of the surface of the convex portions of the pattern, and reduces the filling ability of the pattern reversal resin composition, causing defects (voids) in some of the pattern, making it difficult to form a second resist film with good pattern accuracy.In addition, if the substrate, which is the workpiece, has a layer, such as an organic resin layer or an inorganic layer, laminated thereon, which has a coefficient of linear thermal expansion different from that of the substrate, the heat of the pre-bake may cause the substrate to warp.

[0012] One method for preventing the pattern of the first resist film from collapsing or the workpiece from warping due to the heat of prebaking is to reduce the solvent content of the pattern reversal resin composition. However, reducing the solvent content increases the viscosity of the pattern reversal resin composition, reducing its ability to fill the first resist film, making it more likely to produce defects (voids) in the second resist film. Therefore, this method makes it difficult to improve the pattern accuracy of the second resist film.

[0013] Therefore, an object of the present invention is to provide a photocurable composition for pattern reversal that precisely transfers a pattern of a first resist film while suppressing deformation of the pattern of the first resist film, thereby forming a second resist film having an inverse pattern of the concave-convex shape of the first resist film and having etching resistance. Another object of the present invention is to provide a photocurable composition for pattern reversal that precisely transfers the pattern of a first resist film provided on a workpiece, while suppressing warping of the workpiece and suppressing deformation of the pattern of the first resist film, thereby forming a second resist film having an inverse pattern of the concave-convex shape of the first resist film and having etching resistance. Another object of the present invention is to provide a method for manufacturing an electronic or optical device equipped with a semiconductor element having a fine pattern using the photocurable composition for pattern reversal.

[0014] The present inventors conducted extensive research to solve the above problems and found the following: 1. A composition containing an aromatic monomer having a molecular weight of 120 or more, which has a vinyl group and an electron-donating group other than a vinyl group, and a photoacid generator has low viscosity even without the addition of a solvent, has excellent pattern transferability, and can have a reduced solvent content or be solvent-free compared to conventional resin compositions for pattern reversal. 2. By reducing the solvent content of the composition or making it solvent-free, pre-baking is no longer necessary or the pre-baking time can be significantly reduced, making it possible to suppress or prevent thermal deformation of the pattern of the first resist film, which serves as a mold, when molding the composition using the pattern of the first resist film as a mold. 3. By reducing the solvent content of the composition or making it solvent-free, pre-baking is no longer necessary or the pre-baking time can be significantly reduced, making it possible to suppress or prevent warping of the substrate, which is the workpiece, even when a layer with a different coefficient of linear thermal expansion from that of the substrate, such as an organic resin layer or an inorganic layer, is laminated on the substrate. 4. The composition can be rapidly cured by irradiation with light to form a resist film with excellent etching resistance. 5. Use of the composition enables accurate transfer while suppressing pattern deformation of the first resist film. 6. By applying the composition onto the pattern of the first resist film (or filling recesses in the pattern), curing, and then removing the pattern of the first resist film by a method such as etching, a resist film can be formed having a pattern that is an inverse of the concave and convex shapes of the first resist film with high accuracy, and the resist film thus obtained can be suitably used as a mask for etching the surface of a workpiece. The present invention was completed based on these findings.

[0015] That is, the present invention provides a composition for forming a second resist film on a surface of a workpiece using a pattern of a first resist film having a pattern provided on the surface of the workpiece as a mold, the second resist film having a concave-convex inverted pattern of the first resist film, the composition comprising: an aromatic monomer having a vinyl group and an electron-donating group other than a vinyl group and having a molecular weight of 120 or more; and a photoacid generator, the composition being capable of being heated at 25°C and a shear rate of 200 (s -1The present invention provides a photocurable composition for pattern reversal, which has a viscosity of 0.1 to 15 mPa·s when heated to 100°C.

[0016] The present invention also provides the photocurable composition for pattern reversal, which does not contain water or an organic solvent, or which contains water and / or an organic solvent, wherein the total content of water and organic solvent is 5 wt % or less of the total amount of the photocurable composition.

[0017] The present invention also provides the photocurable composition for pattern reversal, wherein the aromatic monomer is a compound represented by the following formula (1-1) and has a molecular weight of 120 or more: (wherein ring Z represents an aromatic hydrocarbon ring or a bonded ring in which two or more aromatic hydrocarbon rings are bonded via a single bond or a linking group; R 1 represents an electron-donating group. n1 and n2 may be the same or different and represent an integer of 1 or more. Note that n1 + n2 is an integer of 2 or more and 6 or less.

[0018] The present invention also provides the photocurable composition for pattern reversal, wherein the total number of atoms, the number of carbon atoms, and the number of hydrogen atoms constituting one molecule of the aromatic monomer satisfy the following formula (A): (number of carbon atoms + number of hydrogen atoms) / total number of atoms≧0.95 (A).

[0019] The present invention also provides a method for manufacturing an electronic or optical device, comprising an etching mask manufacturing step and an etching step of etching a workpiece using the etching mask obtained in the above step, wherein the etching mask manufacturing step comprises the following steps 1, 2, and 3: Step 1: providing a first resist film having a pattern on the surface of the workpiece; Step 2: applying the photocurable composition for pattern reversal onto the pattern of the first resist film provided on the surface of the workpiece, and photocuring the composition; and Step 3: removing the pattern of the first resist film to obtain a second resist film made of a cured product of the photocurable composition and having a pattern that is the inverse of the pattern of the first resist film, and using this second resist film as an etching mask.

[0020] The photocurable composition of the present invention contains an aromatic monomer (1-1) having a molecular weight of 120 or greater, a vinyl group, and an electron-donating group other than a vinyl group, and a photoacid generator (2). This composition exhibits low viscosity even without the addition of a solvent and excellent fillability into a first resist film. Furthermore, the photocurable composition exhibits excellent photoresponsiveness and rapidly cures upon exposure to light. Therefore, use of the photocurable composition eliminates the need for a prebake process or significantly reduces the prebake time, thereby eliminating the problem of pattern deformation of the first resist film caused by the prebake process. Furthermore, even when a substrate, which is a workpiece, is laminated with a layer having a different coefficient of linear thermal expansion from the substrate, such as an organic resin layer or an inorganic layer, the use of the photocurable composition of the present invention can eliminate the problem of substrate warpage caused by the prebake process. Furthermore, use of the photocurable composition eliminates or significantly reduces the energy required for the prebake process to evaporate the solvent, thereby saving energy and reducing carbon dioxide (CO2) emissions. Furthermore, the cured product of the photocurable composition has excellent etching resistance. A photocurable composition having the above properties is filled into the recesses of a pattern of a first resist film, cured, and then the first resist film is removed by etching to form a resist film (i.e., a second resist film) having a highly accurate fine pattern (e.g., a fine pattern having a high aspect ratio). Furthermore, by using the resist film (i.e., the second resist film) as an etching mask, semiconductor elements having fine circuit patterns can be formed, which can greatly contribute to increasing the capacity and miniaturizing electronic devices. Furthermore, by using the resist film (i.e., the second resist film) as an etching mask, surface nanostructures and thin-wire waveguides of optical devices can be formed easily and at low cost.

[0021] FIG. 1 is a diagram showing an SEM image (a) of the surface and an SEM image (b) of the cross section of a first resist film used in Examples and Comparative Examples. FIG. 2 is a diagram showing an SEM image (a) of the surface and an SEM image (b) of the cross section of a second resist film obtained using the composition of Example 1. FIG. 3 is a diagram showing an SEM image (a) of the surface and an SEM image (b) of the cross section of a second resist film obtained using the composition of Comparative Example 1. FIG. 4 is a schematic diagram illustrating a method for producing a second resist film from a first resist film formed by an imprint method using the photocurable composition for pattern reversal of the present invention. FIG. 5 is a schematic diagram illustrating a method for producing a second resist film from a first resist film formed by a photolithography method using the photocurable composition for pattern reversal of the present invention.

[0022] [Photocurable composition for pattern reversal] The photocurable composition of the present invention comprises a resin component (1) and a photoacid generator (2), wherein the resin component (1) comprises an aromatic monomer (1-1) having a vinyl group and an electron-donating group (excluding a vinyl group) and having a molecular weight of 120 or more.

[0023] The photocurable composition is useful as a composition for forming a second resist film on the surface of a workpiece, using the pattern of a first resist film having a pattern provided on the surface of the workpiece as a mold, the second resist film having a concave-convex inverted pattern of the first resist film, i.e., a photocurable composition for pattern reversal.

[0024] Furthermore, a cured product of the photocurable composition has excellent resistance to dry etching (e.g., dry etching using a fluorine-based gas such as CF4 or CF8), making the photocurable composition useful as an etching mask material for a member (e.g., a silicon substrate) to be processed by dry etching.

[0025] The photocurable composition was heated at 25°C and a shear rate of 200 (s -1) is 0.1 to 15 mPa·s. The lower limit of the viscosity is preferably 0.3 mPa·s, more preferably 0.5 mPa·s, particularly preferably 0.6 mPa·s, and most preferably 0.7 mPa·s, from the viewpoints of excellent coatability and the ability to form a coating film of uniform thickness by a method such as spin coating. The upper limit of the viscosity is preferably 12 mPa·s, more preferably 10 mPa·s, particularly preferably 9.9 mPa·s, and most preferably 9.8 mPa·s, from the viewpoints of excellent filling ability into recesses in the pattern of the first resist film and forming a second resist film with good pattern transfer accuracy. The viscosity can be measured by the method described in the Examples.

[0026] (Aromatic Monomer (1-1)) The aromatic monomer (1-1) of the present invention is an aromatic compound having a vinyl group and an electron-donating group (other than a vinyl group).

[0027] The molecular weight of the aromatic monomer (1-1) is 120 or more, for example, 120 to 350. The lower limit of the molecular weight is preferably 130, more preferably 140, particularly preferably 146, most preferably 150, and especially preferably 160, in order to impart good film-forming properties to the photocurable composition. The upper limit of the molecular weight is preferably 300, particularly preferably 270, and most preferably 250, in order to impart good transferability to the photocurable composition.

[0028] When the aromatic monomer (1-1) is an aromatic monomer (1-1a) having a molecular weight of 120 to 200, the proportion of the aromatic monomer (1-1a) in the total amount of resin component (1) is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 85% by weight or more, in order to increase the fluidity of the photocurable composition without reducing its photoresponsiveness and thereby obtain a photocurable composition having good film-forming properties, photoresponsiveness, and transferability. The upper limit of the proportion of the aromatic monomer (1-1a) is, for example, 100% by weight, preferably 95% by weight.

[0029] When the aromatic monomer (1-1) is an aromatic monomer (1-1b) having a molecular weight of more than 200 (for example, more than 200 but not more than 350), the proportion of the aromatic monomer (1-1b) in the total amount of resin component (1) is preferably 5 wt % or more, more preferably 10 wt % or more, even more preferably 15 wt % or more, and particularly preferably 20 wt % or more, in order to increase the fluidity of the photocurable composition without reducing its photoresponsiveness, thereby obtaining a photocurable composition having good photoresponsiveness. The upper limit of the proportion of the aromatic monomer (1-1b) is preferably 50 wt %, more preferably 40 wt %, even more preferably 35 wt %, and particularly preferably 30 wt %, in order to impart good film-forming properties and transferability to the photocurable composition.

[0030] The aromatic monomer (1-1) is, for example, a compound represented by the following formula (1-1). (wherein ring Z represents an aromatic hydrocarbon ring or a bonded ring in which two or more aromatic hydrocarbon rings are bonded via a single bond or a linking group; R 1 represents an electron-donating group. n1 and n2 may be the same or different and represent an integer of 1 or more. Note that n1 + n2 is an integer of 2 or more and 6 or less.

[0031] Examples of the aromatic hydrocarbon ring in the ring Z include aromatic hydrocarbon rings having 6 to 15 carbon atoms, such as a benzene ring and a naphthalene ring.

[0032] Examples of the linking group include a hydrocarbon group, a carbonyl group (-CO-), an ether bond (-O-), a thioether bond (-S-), an ester bond (-COO-), an amide bond (-CONH-), and a carbonate bond (-OCOO-). Among these, a hydrocarbon group or a carbonyl group (-CO-) is preferred, and a hydrocarbon group is particularly preferred, in terms of forming a cured product with excellent etching resistance. Examples of the hydrocarbon group include C 1-5 Alkylene group, C 2-5 Examples thereof include an alkenylene group.

[0033] Examples of the aromatic hydrocarbon ring in ring Z and the rings connected thereto include rings represented by the following formulae (z-1) to (z-7).

[0034] The ring Z is preferably a benzene ring represented by the formula (z-1). Therefore, the aromatic monomer (1-1) is particularly preferably a compound represented by the following formula (1-1-1): (In the formula, R 1 represents an electron-donating group. n1 and n2 may be the same or different and represent an integer of 1 or more. Note that n1 + n2 is an integer of 2 or more and 6 or less.

[0035] The number (n1) of vinyl groups contained in the aromatic monomer (1-1) is an integer of 1 or more, preferably 2 or more, and particularly preferably 2 or 3.

[0036] When the aromatic monomer (1-1) has two vinyl groups (when n1=2), the bonding positions of the two vinyl groups to the ring Z are not particularly limited. However, when the ring Z is a benzene ring, the bonding positions are preferably the meta or para positions, and particularly preferably the meta positions.

[0037] The electron-donating group is an electron-donating group other than a vinyl group, and examples thereof include a —R group, a —OH group, a —OR group, a —NH 2 group, a —NHR group, and a —NR 2 group.

[0038] The R represents a hydrocarbon group, and includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and groups formed by combining these groups.

[0039] The aliphatic hydrocarbon group may be C 1-20Aliphatic hydrocarbon groups (i.e., aliphatic hydrocarbon groups having 1 to 20 carbon atoms) are preferred, and examples thereof include alkyl groups having 1 to 20 carbon atoms (preferably 1 to 10, particularly preferably 1 to 3), such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, decyl, and dodecyl; alkenyl groups having 3 to 20 carbon atoms (preferably 3 to 10, particularly preferably 3 to 5), such as allyl and 1-butenyl; and alkynyl groups having 2 to 20 carbon atoms (preferably 2 to 10, particularly preferably 2 to 3), such as ethynyl and propynyl.

[0040] The alicyclic hydrocarbon group includes C 3-20 Alicyclic hydrocarbon groups (i.e., 3- to 20-membered alicyclic hydrocarbon groups) are preferred, and examples thereof include 3- to 20-membered (preferably 3- to 15-membered, particularly preferably 5- to 8-membered) cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and cyclooctyl group; 3- to 20-membered (preferably 3- to 15-membered, particularly preferably 5- to 8-membered) cycloalkenyl groups such as cyclopentenyl group and cyclohexenyl group; perhydronaphthalen-1-yl group, norbornyl group, adamantyl group, tricyclo[5.2.1.0] group, 2,6 ] decan-8-yl group, tetracyclo[4.4.0.1 2,5 .1 7,10 ] Bridged cyclic hydrocarbon groups such as dodecan-3-yl group and the like are also included.

[0041] The aromatic hydrocarbon group may be C 6-14 Aromatic hydrocarbon groups (especially C 6-10 Aromatic hydrocarbon groups are preferred, and examples thereof include a phenyl group and a naphthyl group.

[0042] The hydrocarbon group in the electron-donating group is preferably an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a group in which these are bonded via a single bond, in order to form a cured product having excellent etching resistance.

[0043] As the electron-donating group, from the viewpoint of imparting good photoresponsiveness, a group having a heteroatom (particularly, an oxygen atom or a nitrogen atom), such as an -OH group, an -OR group, an -NHR group, or an -NHR group, is preferred, with an -OR group being particularly preferred. Furthermore, R is preferably an aliphatic hydrocarbon group, with an alkyl group (for example, an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms) being particularly preferred.

[0044] The electron-donating group is preferably bonded to the ortho-position or para-position relative to the position at which the vinyl group of the aromatic monomer (1-1) is bonded, and particularly preferably to the ortho-position, in terms of increasing the reactivity of the vinyl group and obtaining the effect of forming a cured product having excellent etching resistance.

[0045] The number of electron-donating groups (n2) is an integer of 1 or more, preferably an integer of 1 to 3, particularly preferably 1 or 2, and most preferably 1.

[0046] The number of vinyl groups (n1) and the number of electron-donating groups (n2) contained in the aromatic monomer (1-1) are each an integer of 1 or more and satisfy the following formula: 2≦n1+n2≦6

[0047] The upper limit of (n1+n2) is preferably 5, particularly preferably 4, and most preferably 3.

[0048] The lower limit of (n1+n2) is preferably 3.

[0049] The aromatic monomer (1-1) preferably has a high ratio of carbon atoms and hydrogen atoms to the total number of atoms constituting one molecule, i.e., a low ratio of atoms other than carbon atoms and hydrogen atoms to the total number of atoms, in order to form a cured product with excellent etching resistance. The total number of atoms, the number of carbon atoms, and the number of hydrogen atoms preferably satisfy the following formula (A), and particularly preferably satisfy the following formula (A-1): 0.95≦[(number of carbon atoms+number of hydrogen atoms) / total number of atoms]≦1 (A) 0.96≦[(number of carbon atoms+number of hydrogen atoms) / total number of atoms]≦1 (A-1)

[0050] Furthermore, the aromatic monomer (1-1) preferably has an electron-donating group containing a heteroatom other than carbon and hydrogen atoms (particularly, an oxygen atom or a nitrogen atom) in order to form a cured product with excellent photoresponsiveness, and the total number of atoms, the number of carbon atoms, and the number of hydrogen atoms preferably satisfy the following formula (A-2), and particularly preferably satisfy the following formula (A-3): 0.95≦[(number of carbon atoms+number of hydrogen atoms) / total number of atoms]≦0.99 (A-2) 0.96≦[(number of carbon atoms+number of hydrogen atoms) / total number of atoms]≦0.99 (A-3)

[0051] (Another Monomer (1-2)) The resin component (1) may contain another monomer (hereinafter, sometimes referred to as "monomer (1-2)") in addition to the aromatic monomer (1-1).

[0052] The monomer (1-2) may be any monomer having a group polymerizable with the vinyl group contained in the aromatic monomer (1-1), and examples of the group polymerizable with the vinyl group include cationically polymerizable groups such as a vinyl group, an epoxy group, and an oxetane group, and radically polymerizable groups such as a (meth)acryloyl group. Of these, cationically polymerizable groups are preferred, and vinyl groups are particularly preferred, in that they provide the effect of forming a cured product with excellent etching resistance.

[0053] Therefore, the monomer (1-2) is preferably a vinyl monomer.

[0054] The number of vinyl groups contained in the monomer (1-2) is preferably one or more (for example, one to three), and more preferably one or two.

[0055] Furthermore, as the monomer (1-2), an aromatic monomer is preferred in that it is possible to obtain the effect of forming a cured product having excellent etching resistance.

[0056] From the above, the monomer (1-2) is preferably a vinyl aromatic compound represented by the following formula (1-2). (In the formula, ring Z represents an aromatic hydrocarbon ring or a bonded ring in which two or more aromatic hydrocarbon rings are bonded via a single bond or a linking group. R 2 represents a substituent; n3 represents an integer of 1 or more; and n4 represents an integer of 0 or more.

[0057] Examples of ring Z in formula (1-2) include the same as those of ring Z in formula (1-1) above.

[0058] As the ring Z, the rings represented by the above formulae (z-1) to (z-7) are preferred, and a benzene ring is particularly preferred.

[0059] Therefore, as the monomer (1-2), a compound represented by the following formula (1-2-1) is particularly preferred. (In the formula, R 2 represents a substituent; n3 represents an integer of 1 or more; and n4 represents an integer of 0 or more.

[0060] The R 2 is a substituent bonded to ring Z, and examples thereof include electron-donating groups such as -R group, -OH group, -OR group, -NH group, -NHR group, and -NR group. R represents a hydrocarbon group, and examples thereof are the same as those mentioned above.

[0061] The R 2 Among these, a -R group is preferred. Furthermore, R is preferably an aliphatic hydrocarbon group, and particularly preferably an alkyl group (for example, an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms).

[0062] In the above formulas (1-2) and (1-2-1), n3 is an integer of 1 or more, for example, an integer of 1 to 3, and preferably 1 or 2.

[0063] In the above formulas (1-2) and (1-2-1), n4 is an integer of 0 or more, for example, an integer of 0 to 3, preferably an integer of 0 to 2, and particularly preferably 1 or 2.

[0064] When n3=2 in the above formula (1-2-1), there are no particular restrictions on the bonding positions of the two vinyl groups to the benzene ring, but meta or para positions are preferred, and meta positions are particularly preferred.

[0065] In the above formula (1-2-1), R 2 The bonding position of to the benzene ring is not particularly limited, but the meta or para position relative to the bonding position of the vinyl group is preferred, and the meta position is particularly preferred.

[0066] It is preferable that the proportion of the number of carbon atoms and the number of hydrogen atoms in the total number of atoms constituting one molecule of the monomer (1-2) is high, that is, that the proportion of atoms other than carbon atoms and hydrogen atoms in the total number of atoms is low, from the viewpoint of forming a cured product having excellent etching resistance. It is preferable that the total number of atoms, the number of carbon atoms, and the number of hydrogen atoms satisfy the above formula (A), and it is particularly preferable that they satisfy the above formula (A-1).

[0067] Monomer (1-2) is preferably a compound having a lower or higher molecular weight than aromatic monomer (1-1), and its molecular weight is, for example, 104 to 350. The lower limit of the molecular weight is preferably 110, more preferably 115, from the viewpoint of imparting good film-forming properties to the photocurable composition. The upper limit of the molecular weight is preferably 250, more preferably 200, even more preferably 180, even more preferably 150, still more preferably 140, particularly preferably 130, most preferably 125, and especially preferably 120, from the viewpoint of imparting good transferability without reducing the photoresponsiveness of the photocurable composition.

[0068] When the molecular weight of the aromatic monomer (1-1) exceeds 200, the monomer (1-2) used in combination with the aromatic monomer (1-1) is preferably a compound having a molecular weight of 104 to 200, in order to improve the fluidity of the photocurable composition without reducing its photoresponsiveness and to impart good transferability to the photocurable composition. The upper limit of the molecular weight of the monomer (1-2) is more preferably 180, even more preferably 160, even more preferably 150, even more preferably 145, even more preferably 140, particularly preferably 130, most preferably 125, and particularly preferably 120. The lower limit of the molecular weight of the monomer (1-2) is more preferably 110, especially preferably 115, in order to impart good film-forming properties to the photocurable composition. The monomer (1-2) may have a substituent other than the vinyl group, and the other substituent may be an electron-donating group such as an -R group, an -OH group, an -OR group, an -NH group, an -NHR group, or an -NR group. The R represents a hydrocarbon group, and examples thereof are the same as those described above.

[0069] When the molecular weight of aromatic monomer (1-1) is 200 or less, monomer (1-2) used in combination with aromatic monomer (1-1) is preferably a compound having a molecular weight of more than 200 (e.g., more than 200 but not more than 350), particularly preferably a compound having a molecular weight of 250 or more, and most preferably a compound having a molecular weight of 300 or more, in order to moderately increase the viscosity of the photocurable composition without reducing the photoresponsiveness of the composition and to impart good coating film formability to the photocurable composition. Furthermore, the monomer (1-2) may have a substituent other than the vinyl group, and may have an electron-donating group such as an -R group, an -OH group, an -OR group, an -NH group, an -NHR group, or an -NR group as the substituent. R represents a hydrocarbon group, and examples thereof include those similar to those described above.

[0070] When the photocurable composition contains the aromatic monomer (1-1) and the monomer (1-2), the total content of the aromatic monomer (1-1) and the monomer (1-2) is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 85% by weight or more of the total amount of the resin component (1), with the upper limit being 100% by weight.

[0071] When the photocurable composition contains aromatic monomer (1-1) and monomer (1-2), the total content of aromatic monomer (1-1) and monomer (1-2) is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 85% by weight or more of the total amount of monomers contained in resin component (1), with the upper limit being 100% by weight.

[0072] When the photocurable composition contains the aromatic monomer (1-1) and the monomer (1-2), the blending ratio thereof (former / latter; weight ratio) is, for example, in the range of 10 / 90 to 90 / 10 (preferably 15 / 85 to 85 / 15, particularly preferably 80 / 20 to 20 / 80), and the photocurable composition is heated at 25°C and a shear rate of 200 (s -1 It is preferable to adjust the viscosity in the range of 0.1 to 15 mPa·s.

[0073] (Polymer (1-3)) The resin component (1) may contain a polymer (including an oligomer, hereinafter sometimes referred to as "polymer (1-3))") in addition to the above-mentioned monomers.

[0074] The molecular weight of the polymer (1-3) is, for example, 500 or more, preferably 1000 or more, and particularly preferably 1500 or more. From the viewpoint of improving etching accuracy, the upper limit of the molecular weight is, for example, 5000, preferably 4000, and particularly preferably 3000.

[0075] When the viscosity of the photocurable composition is low, adding the polymer (1-3) having the above molecular weight can increase the viscosity and provide good film-forming properties.

[0076] As the polymer (1-3), from the viewpoint of preventing a decrease in the etching resistance of the resulting cured product, a compound having a bonded ring structure in which aromatic hydrocarbon rings are bonded via a single bond or a linking group is preferred, and a compound represented by the following formula (1-3) is particularly preferred: (In the formula, ring Z 1 ~Z 3 are the same or different and represent an aromatic hydrocarbon ring or a bonded ring in which two or more aromatic hydrocarbon rings are bonded via a single bond or a linking group; L 1 , L 2 are the same or different and represent a single bond or a linking group; and m represents an integer of 0 or more.

[0077] Ring Z in formula (1-3) 1 ~Z 3 Examples of the ring include the same as those of ring Z in formula (1-1).

[0078] The ring Z 1 ~Z 3 As the ring, the rings represented by the above formulae (z-1) to (z-7) are preferred.

[0079] The ring Z 1 ~Z 3 may have a substituent, and examples of the substituent include an -R group, an -OH group, an -OR group, an -NH group, an -NHR group, an -NR group, the cationically polymerizable group, the radically polymerizable group, etc. Furthermore, the R represents a hydrocarbon group, and examples thereof include the same as those described above.

[0080] L 1 , L 2 Examples of the linking group in the formula (I) include a hydrocarbon group, a carbonyl group (-CO-), an ether bond (-O-), a thioether bond (-S-), an ester bond (-COO-), an amide bond (-CONH-), and a carbonate bond (-OCOO-). Among these, a hydrocarbon group or a carbonyl group (-CO-) is preferred, and a hydrocarbon group is particularly preferred, in terms of forming a cured product with excellent etching resistance. Examples of the hydrocarbon group include C 1-5 Alkylene group, C 2-5 Examples thereof include an alkenylene group.

[0081] When m is an integer of 2 or more, m Z 2 The m L2s may be the same or different.

[0082] It is preferable that the polymer (1-3) has a high ratio of carbon atoms and hydrogen atoms to the total number of atoms constituting one molecule, that is, a low ratio of atoms other than carbon atoms and hydrogen atoms to the total number of atoms, from the viewpoint of forming a cured product having excellent etching resistance. The total number of atoms, the number of carbon atoms, and the number of hydrogen atoms preferably satisfy the above formula (A), and particularly preferably satisfy the above formula (A-1).

[0083] The resin component (1) may further contain other compounds, but the content of compounds in which the ratio of carbon atoms and hydrogen atoms to the total number of atoms constituting one molecule is low, i.e., compounds in which the ratio of atoms other than carbon atoms and hydrogen atoms to the total number of atoms is high (for example, compounds satisfying the following formula (X)) is, for example, 30% by weight or less of the total amount of resin component (1), is preferred from the viewpoint of forming a cured product with excellent etching resistance, more preferably 20% by weight or less, particularly preferably 10% by weight or less, most preferably 5% by weight or less, and particularly preferably 1% by weight or less. [(number of carbon atoms + number of hydrogen atoms) / total number of atoms]<0.95 (X)

[0084] (Photoacid Generator (2)) The photoacid generator (2) of the present invention is a compound that generates an acid upon exposure to light. The generated acid initiates the cationic polymerization reaction of the aromatic monomer (1-1).

[0085] The photoacid generator (2) includes an ionic photoacid generator (2-1) and a nonionic photoacid generator (2-2).

[0086] The ionic photoacid generator (2-1) is a compound comprising a cation moiety that absorbs light and an anion moiety that serves as an acid generating source, and examples thereof include compounds represented by the following formula (2-1). (In the formula, E represents an element having a valence of m selected from S, I, N, and P, and m represents an integer of 1 to 3. R 11 represents an organic group. (m+1) R 11 may be the same or different. 11 are linked to each other via a single bond, or are linked to each other via —O—, —S—, —SO—, —SO2—, —NH—, —CO—, —COO—, —CONH—, C 1-5 Alkylene group or C 6-14 They may be linked via an arylene group to form a ring structure together with the adjacent E. - indicates a monovalent counter anion)

[0087] The R 11 Examples of the organic group in the formula include an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms, and a group in which two or more of the above groups are bonded via a single bond. The above group may have a substituent. Examples of the substituent include a nitro group, a hydroxyl group, a cyano group, -OR 3 group, -COR 3 Group, -COOR 3 group, -SR 3 group, -NR 3 2 groups, halogen atoms, etc. 3 represents a hydrogen atom or a hydrocarbon group. Examples of the hydrocarbon group include the same hydrocarbon groups as those represented by R above.

[0088] The R 11As the group, a group containing an aryl group having 6 to 14 carbon atoms is preferred in that it enhances the sensitivity to light of a short wavelength.

[0089] The X - represents a monovalent counter anion, and examples thereof include a halogen ion, a halogen oxo acid anion, a boron anion, a phosphate anion, a sulfate anion, a sulfonate anion, a sulfonylimide anion, a carboxylate anion, a gallate anion, a methide anion, an antimony anion, and OH - , SCN - , NO2 - , NO3 - etc.

[0090] Examples of the halogen ions include Cl - ,Br - , I - etc.

[0091] Examples of the halogen oxo acid anion include ClO - , IO3 - , BrO - etc.

[0092] The boron anion may be, for example, BF4 - Inorganic boron anions such as (C6F5)4B - , ((CF3)2C6H3)4B - , tetraphenylborate, tetrakis(monofluorophenyl)borate, tetrakis(difluorophenyl)borate, tetrakis(trifluorophenyl)borate, tetrakis(pentafluorophenyl)borate, and other organic boron anions.

[0093] The phosphate anion may be, for example, PF6 - , PF(C2F5)5 - , PF2(C2F5)4 - , PF3(C2F5)3 - , PF4(C2F5)2 - , PF5 (C2F5) - , PO4 3- and the like.

[0094] The sulfonate anion is represented by, for example, the following formula (s1): s1 -SO3 - (s1) (wherein, R s1 indicates an organic group)

[0095] R s1 The organic group in the formula (I) may be, for example, a C 1-30 Hydrocarbon groups, heterocyclic groups which may have a substituent, and groups in which two or more of the above groups are joined by a single bond, -O-, -CO2-, -S-, -SO3-, and -SON(R s2 )- is a group linked to the other group.

[0096] The R s2 is a hydrogen atom or an alkyl group (e.g., C 1-30 alkyl group).

[0097] Examples of the substituent include halogen atoms such as fluorine atoms.

[0098] Said C 1-30 The hydrocarbon group includes C 1-30 Aliphatic hydrocarbon group, C 3-30 Alicyclic hydrocarbon group, C 6-30 Aromatic hydrocarbon groups and groups in which two of these are combined are included.

[0099] Said C 1-30 The hydrocarbon group includes C 1-30 Alkyl group, C 6-15 Aryl group, C 6-15 Cycloalkylene group, C 6-15 Bridged cyclic hydrocarbon groups and groups in which two of these are bonded together are preferred.

[0100] The heterocyclic group is a group in which one hydrogen atom has been removed from the structural formula of a heterocycle. The heterocycle includes aromatic heterocycles and non-aromatic heterocycles. Examples of such heterocycles include 3- to 10-membered rings (preferably 4- to 6-membered rings) containing carbon atoms and at least one heteroatom (e.g., oxygen atom, sulfur atom, nitrogen atom, etc.) as ring-constituting atoms, and condensed rings thereof.

[0101] Specific examples of the sulfonate anion include CH3SO3- (MsO - ), C4H9SO3 - , CF3SO3 - (TfO - ), C2F5C4H4SO3 - , C4F9SO3 - , benzenesulfonate anion, p-toluenesulfonate anion, and camphorsulfonate anion.

[0102] The sulfonylimide anion is represented, for example, by the following formula (n1): (R n1 SO2)2N - (n1) (wherein two R n1 are the same or different and represent an organic group.

[0103] R n1 The organic group in s1 Examples of the organic group are the same as those in the above.

[0104] Specific examples of the sulfonylimide anion include (FSO2)2N - , (CF3SO2)2N - , (C4F9SO2)2N - , (C2F5SO2)2N - etc.

[0105] The carboxylate anion is represented by, for example, the following formula (c1): c1 -COO - (c1) (wherein, R c1 indicates an organic group)

[0106] R c1 The organic group in s1 Examples of the organic group are the same as those in the above.

[0107] Specific examples of the carboxylic acid anion include CF3CO2 - , CH3CO2 - , C2H5CO2 - , PhCO2 - etc.

[0108] The gallate anion is represented, for example, by the following formula (g1): (R g1 )t (F) 4-t Ga - (g1) (wherein, R g1 represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, and t represents an integer of 1 to 4.

[0109] R g1 The fluoroalkyl group in the formula (I) is a group in which at least one hydrogen atom bonded to an alkyl group is substituted with a fluorine atom, and among these, a perfluoroalkyl group is preferred, and perfluoroC 1-5 Alkyl groups are particularly preferred, and perfluoro C 1-3 Alkyl groups are most preferred.

[0110] R g1 The fluoroaryl group in the formula (I) is a group in which at least one hydrogen atom bonded to an aryl group is substituted with a fluorine atom. As the aryl group, for example, an aryl group having 6 to 14 carbon atoms such as a phenyl group or a naphthyl group is preferred, and a phenyl group is particularly preferred.

[0111] R g1 As the fluoroaryl group in the formula (I), a perfluoroaryl group is preferable, and perfluoro C 6-14 Aryl groups are particularly preferred, with perfluorophenyl groups being most preferred.

[0112] R g1 The fluoroalkyl-substituted aryl group in the formula (I) is an aryl group having, as a substituent, a group in which at least one hydrogen atom bonded to an alkyl group is substituted with a fluorine atom.

[0113] R g1 As the fluoroalkyl-substituted aryl group in the formula (I), a perfluoroalkyl-substituted aryl group is preferred, and perfluoro C 1-5 Alkyl-substituted aryl groups are more preferred, and perfluoro C 1-3 Alkyl-substituted C 6-14 Phenyl groups are particularly preferred.

[0114] Also, R g1The number of fluoroalkyl groups in the fluoroalkyl-substituted aryl group is, for example, 1 to 5, preferably 1 to 3, and particularly preferably 1 or 2.

[0115] In formula (g1), t represents an integer of 1 to 4, preferably an integer of 2 to 4, particularly preferably 3 or 4, and most preferably 4.

[0116] Examples of the gallate anion include tetrakis[fluorophenyl]gallate anions such as tetrafluorogallate anion and tetrakis(pentafluorophenyl)gallate anion; tetrakis[fluorophenyl]gallate anions such as tetrakis(4-fluorophenyl)gallate anion; tetrakis[difluorophenyl]gallate anions such as tetrakis(3,5-difluorophenyl)gallate anion; tris(pentafluorophenyl)fluorogallate anion, bis(pentafluorophenyl)difluorogallate anion, (pentafluorophenyl)trifluorogallate anion; and tetrakis[(C 1-5 tetrakis[bis(C haloalkyl)phenyl]gallate anion; tetrakis[bis(C haloalkyl)phenyl]gallate anion, such as tetrakis[3,5-bis(trifluoromethyl)phenyl]gallate anion; 1-5 tris[(C haloalkyl)phenyl]gallate anion, such as tris[4-(trifluoromethyl)phenyl]fluorogallate anion; 1-5 tris[bis(C haloalkyl)phenyl]fluorogallate anion, etc.; tris[bis(C 1-5 haloalkyl)phenyl]fluorogallate anion, etc.; bis[(C 1-5 bis[bis(C haloalkyl)phenyl]difluorogallate anion; bis[3,5-bis(trifluoromethyl)phenyl]difluorogallate anion, etc. 1-5 [(C haloalkyl)phenyl]difluorodifluorogallate anion; [4-(trifluoromethyl)phenyl]trifluorogallate anion, etc.1-5 [bis(C haloalkyl)phenyl]trifluorogallate anion; [3,5-bis(trifluoromethyl)phenyl]trifluorogallate anion, etc. 1-5 haloalkyl)phenyl]trifluorogallate anion and the like.

[0117] The methide anion may, for example, be a sulfonylmethide anion represented by the following formula (m1): (R m1 SO2)3C - (m1) (wherein three R m1 are the same or different and represent an organic group.

[0118] R m1 The organic group in s1 Examples of the organic group are the same as those in the above.

[0119] Specific examples of the methide anion include (CF3SO2)3C - etc.

[0120] The antimony anion may be, for example, SbF - etc.

[0121] In addition to the above, the monovalent counter anion includes, for example, the anions described in JP-A-2013-47211, JP-A-2021-81708, JP-A-2013-80245, JP-A-2013-80240, and JP-A-2013-33161.

[0122] The counter anion is preferably a sulfonate anion, a sulfonylimide anion, or a halogen ion, in that it improves sensitivity to light of a short wavelength and has excellent solvent solubility.

[0123] Examples of the nonionic photoacid generator (2-2) include compounds represented by the following formulas (2-2a), (2-2b), and (2-2c). (In the formula, R 12 , R 13 , R 14 are the same or different and represent an organic group. 13 and R 14are linked to each other via a single bond, or are linked to each other via —O—, —S—, —SO—, —SO2—, —NH—, —CO—, —COO—, —CONH—, C 1-5 Alkylene group or C 6-14 They may be linked via an arylene group to form a ring structure.

[0124] The R 12 , R 13 , R 14 The organic group in R 11 Examples of the organic group are the same as those in the above.

[0125] As the photoacid generator (2), an ionic photoacid generator (2-1) is particularly preferred, since it can generate a super strong acid and can form the second resist film with high precision.

[0126] The content of the photoacid generator (2) is, for example, 0.1 to 5 parts by weight per 100 parts by weight of the resin component (1).

[0127] (Others) In addition to the above components, the photocurable composition may contain, as necessary, one or more selected from a sensitizer, a surfactant, a pigment, a dye, a dispersant, a filler, a leveling agent, an antifoaming agent, an antistatic agent, a flame retardant, a flow adjuster, an adhesion imparting agent, an antioxidant, an ion scavenger, a light stabilizer, an ultraviolet absorber, a pH adjuster, a surface modifier, a plasticizer, a drying accelerator, and the like.

[0128] The sensitizer is a compound that has the effect of accelerating the photodecomposition of a photoacid generator upon exposure to light to generate an acid, and examples thereof include anthracene derivatives such as 9,10-dibutoxyanthracene and 9,10-diethoxyanthracene; benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether, and α,α-dimethoxy-α-phenylacetophenone; benzophenone derivatives such as benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4′-bis(dimethylamino)benzophenone, and 4,4′-bis(diethylamino)benzophenone; carbonyl compounds such as anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; organic sulfur compounds such as thioxanthone derivatives such as 2-chlorothioxanthone, 2-isopropylthioxanthone, and 2,4-diethylthioxanthen-9-one; persulfides; redox compounds; azo compounds; diazo compounds; halogen compounds; and photoreducible dyes. These can be used alone or in combination of two or more. Among these, anthracene derivatives and thioxanthone derivatives are preferred as the sensitizer.

[0129] The content of the sensitizer is, for example, 0.1 to 1 part by weight per 1 part by weight of the photoacid generator (2).

[0130] The surfactant is a compound that has the effect of improving the wettability of the photocurable composition and further improving the transferability. Examples of the surfactant include fluorine-based surfactants, silicone-based surfactants, alkyl-based surfactants, and acrylic-based surfactants. These surfactants can be used alone or in combination of two or more.

[0131] The content of the surfactant is, for example, 0.1 to 5 parts by weight per 100 parts by weight of the resin component (1).

[0132] Since the resin component (1) in the photocurable composition has low viscosity and excellent fluidity, there is no need to add a solvent to further reduce the viscosity. Therefore, the photocurable composition does not need to contain a solvent (water and / or organic solvent). When the photocurable composition contains a solvent, in order to suppress pattern deformation of the first resist film, the solvent content (total content of water and organic solvent) is preferably, for example, 5 wt % or less of the total amount of the photocurable composition, more preferably 4 wt % or less, even more preferably 3 wt % or less, even more preferably 2 wt % or less, particularly preferably 1 wt % or less, most preferably 0.55 wt % or less, and particularly preferably 0.1 wt % or less.

[0133] The photocurable composition can be prepared by blending and mixing the resin component (1), the photoacid generator (2), and, if necessary, other components.

[0134] [Method for Manufacturing an Electronic or Optical Device] The method for manufacturing an electronic or optical device of the present invention includes an etching mask manufacturing step, and an etching step of etching a workpiece using the etching mask obtained in the above step.

[0135] (Etching Mask Manufacturing Process) The etching mask manufacturing process includes the following steps 1, 2, and 3. Step 1: Providing a first resist film having a pattern on the surface of a workpiece. Step 2: Applying the photocurable composition onto the pattern of the first resist film provided on the surface of the workpiece and photocuring it. Step 3: Removing the pattern of the first resist film to obtain a second resist film made of a cured product of the photocurable composition and having a pattern that is an inverse of the pattern of the first resist film, and using this as an etching mask.

[0136] (Step 1) Step 1 is a step of providing a first resist film having a pattern on the surface of a workpiece.

[0137] The workpiece is not particularly limited, but examples thereof include a silicon substrate, a gallium oxide substrate, and a sapphire substrate.

[0138] The first resist film is a resist film having a pattern, and the pattern is, for example, a pattern having a concave-convex reverse shape of a pattern that should be provided on an etching mask.

[0139] The first resist film is preferably a film that can be easily removed after the photocurable composition is cured, and in particular, is preferably a film that can be easily removed by dry etching using a fluorine-based gas plasma such as CF4 or C4F8, or by wet etching using an alkaline or fluorine-based etching solution.

[0140] The method for providing the first resist film on the surface of the workpiece is not particularly limited, and examples thereof include photoimprinting, thermal imprinting, and photolithography.

[0141] In the present invention, among these, the optical imprint method or the photolithography method is preferred in that a fine pattern can be formed with high precision.

[0142] In this step, the pattern of the first resist film is preferably a pattern with a low aspect ratio, because when a photoimprinting method is employed, it is possible to prevent the pattern from being damaged during demolding, and when a photolithography method is employed, it is possible to prevent the pattern from collapsing during the development step and rinsing step, thereby enabling the formation of a first resist film having a highly accurate pattern.

[0143] <Formation of First Resist Film by Photoimprinting Method> When the first resist film is formed by photoimprinting, a well-known and commonly used photocurable composition for imprinting can be used as the composition for forming the first resist film.

[0144] The photocurable composition for imprints is, for example, a composition containing a radical polymerizable compound and a photoradical polymerization initiator. The photocurable composition for imprints may further contain a solvent.

[0145] The radical polymerizable compound is a compound having at least one radical polymerizable group.

[0146] Examples of the radical polymerizable compound include monofunctional or polyfunctional (meth)acrylates and modified products thereof (e.g., ethylene oxide-modified (meth)acrylate, propylene oxide-modified (meth)acrylate, (poly)glycerin-modified (meth)acrylate, etc.) These may be used alone or in combination of two or more.

[0147] Examples of the monofunctional (meth)acrylate include stearyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate.

[0148] Examples of polyfunctional (meth)acrylates include bifunctional (meth)acrylates such as triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin di(meth)acrylate, diglycerin di(meth)acrylate, and (poly)glycerin di(meth)acrylate; trifunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; and trifunctional or higher functional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate.

[0149] Examples of the photoradical polymerization initiator include α-aminoacetophenones such as 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-4-yl-phenyl)butan-1-one; benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; 2,2-dimethoxy-2-phenylacetophenone, and oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propiophenone; benzyl ketals such as 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propan-1-one; hydroxyacetophenones such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. These may be used alone or in combination of two or more.

[0150] The amount of the photoradical polymerization initiator used (blended amount) is, for example, 0.1 to 10% by weight, preferably 1 to 5% by weight, of the total amount of the radical polymerizable compounds.

[0151] An example of a method for forming a first resist film by imprinting using the photocurable composition for imprints is a method including the following steps P1 to P3.

[0152] Step P1: forming a coating film of the photocurable composition for imprints on a workpiece; Step P2: irradiating the coating film with light while pressing a pattern transfer mold against the coating film; and Step P3: releasing the mold.

[0153] (Step P1) Step P1 is a step of forming a coating film of the photocurable composition for imprints on a workpiece to be etched.

[0154] The coating film of the chemically amplified resist can be formed by applying the chemically amplified resist to the workpiece by a known method such as spin coating, curtain coating, roll coating, spray coating, or screen printing, and then drying it.

[0155] The coating may be dried by natural drying or by heating (for example, at a temperature of 50° C. or higher but lower than 130° C. for 1 to 5 minutes).

[0156] The thickness of the coating film is, for example, 1 to 1000 nm.

[0157] (Step P2) In step P2, a pattern transfer mold is pressed against the coating film obtained in step P1, and the coating film is exposed to light in this state. Through this step, a pattern having a concave-convex shape that is the inverse of the pattern to be provided on the etching mask is formed on the coating film.

[0158] The light used for the photoirradiation is not particularly limited as long as it can generate radicals from the photoradical polymerization initiator contained in the coating film, and the wavelength of the light is, for example, 100 to 500 nm. Examples of the light include X-rays, electron beams, EUV, UV, etc.

[0159] The pattern transfer mold is a mold made of a material (such as quartz) that transmits the irradiated light beam.

[0160] <Formation of First Resist Film by Photolithography> When the first resist film is formed by photolithography, a well-known and commonly used chemically amplified resist can be used as the composition for forming the first resist film.

[0161] The chemically amplified resist is, for example, a composition containing a photoacid generator and a photosensitive resin.

[0162] Examples of the photoacid generator include the same examples as those of the photoacid generator (2).

[0163] The photosensitive resin includes a negative photosensitive resin whose solubility decreases when irradiated with light, and a positive photosensitive resin whose solubility increases when irradiated with light.

[0164] Examples of the negative photosensitive resin include a composition containing a phenolic hydroxyl group-containing resin and a crosslinking agent, each of which may be used alone or in combination of two or more.

[0165] Examples of the positive photosensitive resin include alkali-soluble resins (e.g., phenolic hydroxyl group-containing resins, carboxyl group-containing resins, sulfonic acid group-containing resins, etc.) in which some or all of the hydrogen atoms of acidic functional groups (e.g., phenolic hydroxyl groups, carboxyl groups, sulfonyl groups, etc.) have been substituted with acid-dissociable groups (e.g., 1-substituted methyl groups, 1-substituted ethyl groups, 1-branched alkyl groups, alkoxycarbonyl groups, acyl groups, etc.).

[0166] The chemically amplified resist can be prepared, for example, by dissolving the photoacid generator (2) in a solvent and mixing the solution with a photosensitive resin.

[0167] An example of a method for forming a first resist film by photolithography using a chemically amplified resist is a method including the following steps L1 to L3.

[0168] Step L1: A step of forming a coating film of a chemically amplified resist on a workpiece; Step L2: A step of irradiating the coating film with light to transfer a pattern; Step L3: A step of performing alkaline development.

[0169] (Step L1) Step L1 is a step of forming a coating film of a chemically amplified resist on a workpiece to be etched, and is the same as step P1 above, except that a chemically amplified resist is used instead of the photocurable composition for imprints.

[0170] The coating film of the chemically amplified resist can be formed by applying the chemically amplified resist to the workpiece by a known method such as spin coating, curtain coating, roll coating, spray coating, or screen printing, and then drying it.

[0171] The coating may be dried by natural drying or by heating (for example, at a temperature of 50° C. or higher but lower than 130° C. for 1 to 5 minutes).

[0172] The thickness of the coating film is, for example, 1 to 1000 nm.

[0173] (Step L2) Step L2 is a step of transferring a pattern to the coating film obtained through step L1 by irradiating the coating film with light through a patterned photomask, for example. Through this step, a pattern having a concave-convex shape that is the inverse of the pattern to be provided on the etching mask is formed on the coating film.

[0174] The light used for the photoirradiation is not particularly limited as long as it can generate an acid from the photoacid generator (2) contained in the coating film, and the wavelength of the light is, for example, 100 to 500 nm. Examples of the light include X-rays, electron beams, EUV, UV, etc.

[0175] After the light irradiation, the film may be heated at a temperature of 60 to 200° C. for about 0.1 to 120 minutes.

[0176] (Step L3) Step L3 is a step of subjecting the coating film of the chemically amplified resist obtained through step L2 to an alkali development treatment.

[0177] Examples of the alkaline developer used in the alkaline development treatment include an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, sodium hydrogen carbonate, and an aqueous solution of tetramethylammonium salt.

[0178] The alkaline developer may contain methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N-methylpyrrolidone, or the like.

[0179] The temperature of the alkaline developer is, for example, 25 to 40° C. The alkaline development time is determined appropriately depending on the thickness of the resist, but is, for example, about 1 to 5 minutes.

[0180] Through step L3, a first resist film having a pattern can be formed on the workpiece. The first resist film thus obtained is used as a mold (e.g., a resin mold) for forming an etching mask.

[0181] (Step 2) Step 2 is a step of applying the photocurable composition onto the pattern of the first resist film provided on the surface of the workpiece, and photocuring the composition.

[0182] Step 2 preferably includes steps [I] to [II] (see FIG. 4): [I] A step of filling the pattern recesses (2c) of the first resist film provided on the surface of the workpiece (1) with a photocurable composition (3). [II] A step of photocuring the applied photocurable composition (3).

[0183] The method for applying the photocurable composition is not particularly limited as long as it is a method that can fill the pattern recesses of the first resist film with the photocurable composition, and for example, known methods such as spin coating, curtain coating, roll coating, spray coating, and screen printing can be used.

[0184] When the photocurable composition contains a solvent, it is preferable to dry the composition after application. Since the resin component (1) has low viscosity, the photocurable composition contains only a small amount of solvent even when it contains a solvent, and therefore the photocurable composition can be dried by heating while suppressing or preventing pattern deformation of the first resist film.

[0185] The light used to photocure the coating film of the photocurable composition is not particularly limited as long as it can generate an acid from the photoacid generator (2), and the wavelength of the light is, for example, 100 to 500 nm. Examples of the light include X-rays, electron beams, EUV, UV, etc.

[0186] (Step 3) Step 3 is a step of removing the pattern of the first resist film provided on the surface of the workpiece.

[0187] The method for removing the pattern of the first resist film (i.e., the pattern convex portions) may be any method that can remove the pattern of the first resist film (i.e., the pattern convex portions) while suppressing damage to the cured product of the photocurable composition present in the pattern concave portions of the first resist film.

[0188] When the cured product of the photocurable composition is also laminated on the pattern convex portions of the first resist film, it is preferable to first scrape off the cured product on the pattern convex portions by a CMP method or the like to expose the pattern convex surfaces of the first resist film, and then selectively remove the first resist film.

[0189] Step 3 preferably includes steps [III] to [IV] (see FIG. 4 ): [III] A step of exposing the pattern convex portions (2b) of the first resist film; and [IV] A step of removing the pattern convex portions (2b) of the first resist film to obtain a second resist film (5) having pattern convex portions (4) that are the inverse of the pattern convex portions (2b) of the first resist film.

[0190] The pattern of the first resist film can be removed by etching, which includes dry etching using oxygen gas plasma and wet etching using an alkaline or fluorine-based etching solution.

[0191] Since the cured product of the photocurable composition has high etching resistance to dry etching with oxygen gas plasma, it is preferable to utilize the difference in etching resistance to remove the pattern of the first resist film by dry etching, in that a second resist film having a highly accurate pattern can be obtained.

[0192] Through this step, a second resist film is obtained on the surface of the workpiece, which is made of the cured product of the photocurable composition and has a pattern that is the inverse of the pattern of the first resist film.

[0193] According to the present invention, a second resist film having a fine pattern with a high aspect ratio can be formed with high precision.

[0194] (Etching Step of Etching a Workpiece) This step is a step of etching a workpiece using the second resist film obtained through the etching mask manufacturing step as an etching mask.

[0195] As a method for etching the workpiece, it is preferable to use an etching method to which the second resist film has resistance, and in the present invention, it is preferable to use a dry etching method. The etching gas used in the dry etching method can be selected depending on the type of workpiece. For example, when the workpiece is a silicon substrate, it is preferable to use a fluorine-based gas such as CF4 or CF8.

[0196] According to the present invention, by etching a workpiece using an etching mask having a highly accurate fine pattern with a high aspect ratio, it is possible to form a semiconductor element having a fine circuit pattern with high precision, thereby realizing a large capacity and miniaturization of electronic devices. Also, according to the present invention, by etching a workpiece using an etching mask having a highly accurate fine pattern with a high aspect ratio, it is possible to form a surface nanostructure or a thin-wire waveguide of an optical device at low cost and easily.

[0197] Examples of the electronic device include display devices such as organic EL displays and liquid crystal displays; input devices such as touch panels; light-emitting devices; sensor devices; and MEMS (Micro Electro Mechanical Systems) devices such as optical scanners, optical switches, acceleration sensors, pressure sensors, gyroscopes, microchannels, and inkjet heads.

[0198] The optical devices include, for example, optical waveguides, metalenses, semiconductor lasers, and the like.

[0199] The above-described configurations and combinations of the present invention are merely examples, and additions, omissions, substitutions, and modifications of the configurations are possible as appropriate without departing from the spirit of the present invention. Furthermore, each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

[0200] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0201] Synthesis Example 1 [A1-1: Synthesis of benzyl (2,4-divinylphenyl) ether] A three-neck flask equipped with a thermometer, a condenser, and a magnetic stirrer was charged with 25.0 g of 4-hydroxyisophthalaldehyde, 29.9 g of potassium carbonate, and 400 mL of dimethylformamide. 21.8 mL of benzyl bromide was added, and the mixture was heated to 60°C and stirred for 2 hours. Subsequently, 400 mL of dichloromethane and 500 mL of water were added to the reaction solution, and the mixture was separated. The organic layer was concentrated under reduced pressure. 20 mL of dichloromethane and 100 mL of hexane were added to the residue, and the precipitated solid was collected by filtration to obtain 35.3 g of benzyl (2,4-diformylphenyl) ether. Subsequently, a three-neck flask equipped with a thermometer, an ice bath, and a magnetic stirrer was charged with 46.2 g of potassium tert-butoxide and 126 g of methyltriphenylphosphonium bromide, and the atmosphere in the reaction vessel was purged with nitrogen. Thereafter, 250 mL of tetrahydrofuran was added, and the mixture was stirred for 1 hour while still in an ice bath. Then, 580 mL of a benzyl (2,4-diformylphenyl) ether / tetrahydrofuran solution (concentration: 0.25 mol / L) was slowly added dropwise to the reaction vessel, and after the addition was completed, the mixture was stirred at room temperature for 1 hour. 20 mL of acetone was added to the reaction solution to terminate the reaction, and 800 mL of dichloromethane and 800 mL of water were added to separate the layers, and the organic layer was concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain 25.5 g of benzyl (2,4-divinylphenyl) ether (A1-1).

[0202] Synthesis Example 2 [Synthesis of Polymer (B-3)] A three-neck flask equipped with a thermometer, a condenser, and a magnetic stirrer was charged with 50 g of 2,7-dihydroxynaphthalene (molecular weight 160, (number of carbon atoms + number of hydrogen atoms) / total number of atoms=0.90), 9.4 g of paraformaldehyde, 16 g of ion-exchanged water, and 150 g of methyl isobutyl ketone, to which 0.54 g of paratoluenesulfonic acid was added. The mixture was heated to 80°C and stirred for 7 hours to polymerize. After polymerization was completed, the reaction solution was poured into a large amount of a methanol / water (80 / 20 vol%) mixed solution, and the precipitate was collected by filtration to obtain Polymer (B-3) having a repeating unit represented by the following formula [(number of carbon atoms + number of hydrogen atoms) / total number of atoms=0.91]. GPC measurement revealed that the number average molecular weight of Polymer (B-3) was approximately 2,000.

[0203] Preparation Example 1 Triglycerin diacrylate (100 parts by weight), 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (4 parts by weight), and propylene glycol monomethyl ether acetate (5000 parts by weight) were blended to obtain a composition for forming a first resist film.

[0204] Example 1 Monomer A1-1 (25 parts by weight), monomer A2-1 (75 parts by weight), photocationic polymerization initiator C-1 (0.75 parts by weight), sensitizer D-1 (0.15 parts by weight), and surfactant E-1 (0.75 parts by weight) were mixed to obtain composition 1.

[0205] Example 2 Composition 2 was obtained in the same manner as in Example 1, except that the formulation was changed to that shown in Table 1 below.

[0206] Comparative Example 1 Polymer B-3 (10 parts by weight) shown below was mixed with solvent S-1 (90 parts by weight) by stirring to dissolve, thereby obtaining composition 3.

[0207] Comparative Example 2 Composition 4 was obtained in the same manner as in Example 1, except that the formulation was changed to that shown in Table 1 below.

[0208] Comparative Example 3: Composition 1 obtained in the same manner as in Example 1 was subjected to 2000 mJ / cm 2The procedure of Comparative Example 1 was repeated except that the obtained polymer B-4 was used instead of the polymer B-3. However, the polymer B-4 was insoluble in the solvent S-1.

[0209] The viscosity and etching rate of the compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were measured by the following methods.

[0210] [Viscosity Measurement] Using a TV-25 viscometer manufactured by Toki Sangyo, the viscosity was measured at 25°C and a shear rate of 200 (s -1 The viscosity at 1000 kJ / min was measured.

[0211] [Etching Rate Measurement] Dry etching was performed under the following conditions, and the etching rate was measured: O2 gas flow rate: 4 sccm, etching chamber pressure: 0.2 Pa, RF power: 30 W.

[0212] The viscosity and etching rate of the first resist film-forming composition obtained in Preparation Example 1 were measured by the above-mentioned method. -1 The viscosity at 1000 kJ / min was 3.5 mPa·s, and the etching rate was 74.6 nm / min.

[0213] The accuracy of the reverse pattern was evaluated by the following method for the compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2. [Evaluation of Accuracy of Reverse Pattern] [Creation of First Resist Film by Photo-Nanoimprint] A quartz mold was used, which had a line / space pattern (1 / 5) with a line width of 45 nm and a pattern depth of 100 nm, and the pattern surface was treated with a silane coupling agent having a perfluoroalkyl structure.

[0214] The first resist film-forming composition obtained in Preparation Example 1 was applied onto a silicon substrate by spin coating and baked at 50°C for 120 seconds to form a coating film with a thickness of 100 nm. The quartz mold was placed on the obtained coating film under a nitrogen gas flow and pressed onto the substrate at 25°C with a pressure of 1 MPa. Then, 2000 mJ / cm was applied from the backside of the quartz mold. 2After exposure, the quartz mold was released to obtain a first resist film having a pattern. The surface and cross section of the obtained first resist film were observed by SEM. The results are shown in Figure 1.

[0215] The compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were applied onto the resulting first resist film by spin coating to form coating films with a thickness of 200 nm. 2 The coating film obtained in Comparative Example 1 was subjected to a baking treatment at 180° C. for 60 seconds to volatilize the solvent and solidify the coating film.

[0216] Thereafter, the first resist film was removed by dry etching under the following conditions. As a result, a substrate was obtained having a second resist film having a pattern that was the inverse of the pattern of the first resist film. <Dry etching conditions> O2 gas flow rate: 4 sccm, etching chamber pressure: 0.2 Pa, RF power: 30 W

[0217] The surface and cross section of the resulting second resist film were observed by SEM. The results of Example 1 are shown in FIG. 2, and the results of Comparative Example 1 are shown in FIG.

[0218] Furthermore, the pattern of the second resist film was evaluated for pattern width precision, flatness of the pattern convex portions, and the presence or absence of defects (voids) by the following methods.

[0219] <Pattern Width Precision> From the SEM image, the width (w1; nm) of the pattern convex portion of the first resist film and the width (w2; nm) of the pattern concave portion of the second resist film formed by transferring the pattern convex portion were measured, and the transfer precision was evaluated according to the following criteria: Good: w2 satisfies the following formula (1) Poor: w2 does not satisfy the following formula (1) w1 - (w1 × 0.5 / 100) ≦ w2 ≦ w1 + (w1 × 0.5 / 100) (1)

[0220] <Thickness uniformity of pattern convex portion> The thickness (t1; nm) of the second resist film at the center of the pattern convex portion and the thickness (t2; nm) of the pattern convex portion at the end of the pattern convex portion were measured from the SEM image, and the transfer accuracy was evaluated according to the following criteria: Good: |t1 - t2| satisfies the following formula (2) Poor: |t1 - t2| does not satisfy the following formula (2) |t1 - t2|≦5 (2)

[0221] <Presence or Absence of Defects> The pattern of the second resist film was visually observed to check for the presence or absence of defects.

[0222]

[0223] [Monomer (A1)] A1-1: benzyl (2,4-divinylphenyl) ether obtained in Synthesis Example 1, molecular weight 236, [(number of carbon atoms + number of hydrogen atoms) / total number of atoms] = 0.97 A1-2: 2,4-divinylphenyl methyl ether, molecular weight 160, [(number of carbon atoms + number of hydrogen atoms) / total number of atoms] = 0.96 [Other Monomer (A2)] A2-1: vinyltoluene, molecular weight 118, [(number of carbon atoms + number of hydrogen atoms) / total number of atoms] = 1.00 [Polymer (B)] B-1: a compound produced by the method described in Macromolecules, 1980, Vol. 13, No. 6, pp. 1350-1354 (Toshinobu Higashimura), which is represented by the following formula (B-1), having a number average molecular weight of about 2,000 as measured by GPC, [(number of carbon atoms + number of hydrogen atoms) / total number of atoms] = 1 B-2: Polystyrene, number average molecular weight 60,000, [(number of carbon atoms + number of hydrogen atoms) / total number of atoms] = 1, trade name "Toyo Styrol G100C", manufactured by Toyo Styrene Co., Ltd. B-3: Polymer obtained in Synthesis Example 2, number average molecular weight approximately 2,000, [(number of carbon atoms + number of hydrogen atoms) / total number of atoms] = 0.91 [Photoacid generator (C)] C-1: Cumyl-p-tolyliodonium tris(pentafluoroethyl)trifluorophosphate C-2: Cumyl-p-tolyliodonium tetrakis(pentafluorophenyl)borate [Sensitizer (D)] D-1: 9,10-dioctoxyanthracene D-2: 9,10-dibutoxyanthracene [Surfactant (E)] E-1: Megafac F-554 (manufactured by DIC Corporation) [Solvent (S)] S-1: Propylene glycol monomethyl ether acetate

[0224] Table 1 and Figures 1 to 3 show that the use of the photocurable composition for pattern reversal of the present invention can suppress deformation of the pattern of the first resist film during curing, allowing the formation of a second resist film having a highly accurate pattern that is the inverse of the concave-convex shape of the pattern of the first resist film. On the other hand, when a composition is used that does not contain an aromatic monomer having a molecular weight of 120 or more and in which the viscosity is adjusted by diluting the polymer with a solvent, the pattern of the first resist film is prone to thermal deformation during the bake treatment to solidify the composition, making it difficult to form a second resist film having a highly accurate pattern that is the inverse of the concave-convex shape of the pattern of the first resist film. Furthermore, when a composition containing an aromatic monomer having a molecular weight of 120 or more but with too high a viscosity is used, the pattern recesses are poorly filled, preventing the pattern of the first resist film from being transferred with high accuracy, making it difficult to form a second resist film having a highly accurate pattern that is the inverse of the concave-convex shape of the pattern of the first resist film.

[0225]

[0013] In summary, the configuration of the present invention and its variations are described below. [1] A composition for forming a second resist film on a surface of a workpiece using a pattern of a first resist film having a pattern provided on the surface of the workpiece as a mold, the second resist film having a concave-convex reversed pattern of the pattern of the first resist film, the composition comprising: an aromatic monomer having a vinyl group and an electron-donating group other than a vinyl group and having a molecular weight of 120 or more; and a photoacid generator, the composition being heated at 25°C and a shear rate of 200 (s -1 a photocurable composition for pattern reversal having a viscosity of 0.1 to 15 mPa·s at 2000 K. [2] The photocurable composition for pattern reversal according to [1], which does not contain water and an organic solvent, or contains water and / or an organic solvent, with the total content of water and organic solvent being 5 wt % or less of the total amount of the photocurable composition. [3] The photocurable composition for pattern reversal according to [1] or [2], wherein the aromatic monomer is a compound represented by formula (1-1) and has a molecular weight of 120 or more. [4] The photocurable composition for pattern reversal according to any one of [1] to [3], wherein the total number of atoms, the number of carbon atoms, and the number of hydrogen atoms constituting one molecule of the aromatic monomer satisfy the following formula (A): (number of carbon atoms + number of hydrogen atoms) / total number of atoms≧0.95 (A) [5] A method for manufacturing an electronic or optical device, comprising: an etching mask manufacturing step; and an etching step of etching a workpiece using the etching mask obtained in the etching mask manufacturing step, wherein the etching mask manufacturing step comprises the following steps 1, 2, and 3: Step 1: Providing a first resist film having a pattern on the surface of a workpiece; Step 2: Applying the photocurable composition for pattern reversal according to any one of [1] to [4] onto the pattern of the first resist film provided on the surface of a workpiece, and photocuring; Step 3: Removing the pattern of the first resist film to obtain a second resist film made of a cured product of the photocurable composition and having a pattern that is a convex-concave inverse of the pattern of the first resist film, which is used as an etching mask. [6] A photo-curable composition for pattern reversal comprising an aromatic monomer having a vinyl group and an electron-donating group other than a vinyl group, and a molecular weight of 120 or more; and a photoacid generator, and capable of being heated at 25°C and a shear rate of 200 (s -1) is 0.1 to 15 mPa·s, for use in forming a second resist film on the surface of a workpiece, the second resist film having a pattern that is an inverse of the concave-convex pattern of the first resist film, using the pattern of a first resist film provided on the surface of the workpiece as a mold. [7] The use according to [6], wherein the photocurable composition does not contain water or an organic solvent, or contains water and / or an organic solvent, and the total content of water and organic solvent is 5% by weight or less of the total amount of the photocurable composition. [8] The use according to [6] or [7], wherein the aromatic monomer is a compound represented by formula (1-1) and has a molecular weight of 120 or more. [9] The use according to any one of [6] to [8], wherein the total number of atoms, the number of carbon atoms, and the number of hydrogen atoms constituting one molecule of the aromatic monomer satisfy the following formula (A): (number of carbon atoms + number of hydrogen atoms) / total number of atoms≧0.95 (A)

[0226] The photocurable composition of the present invention is filled into the pattern recesses of a first resist film, cured, and then the first resist film is removed by etching, thereby forming a second resist film having a highly accurate fine pattern. By using the second resist film as an etching mask, a semiconductor element having a fine circuit pattern can be formed. Therefore, the photocurable composition of the present invention can greatly contribute to increasing the capacity and reducing the size of electronic devices. Furthermore, by using the second resist film as an etching mask, surface nanostructures and thin-wire waveguides of optical devices can be formed easily and at low cost.

[0227] 1 Workpiece 2a Bottom of first resist film 2b Pattern convex portion of first resist film 2c Pattern concave portion of first resist film 3 Photocurable composition for pattern reversal 4 Photocured product of photocurable composition for pattern reversal 5 Second resist film w1 Width of pattern convex portion (2b) of first resist film w2 Width of pattern concave portion of second resist film t1 Film thickness at center of pattern convex portion of second resist film t2 Film thickness at end of pattern convex portion of second resist film

Claims

1. A composition for forming a second resist film having a pattern that is an inverse shape of the pattern of the first resist film on the surface of a workpiece by using the pattern of the first resist film having a pattern provided on the surface of the workpiece as a mold, the composition comprising: an aromatic monomer having a molecular weight of 120 or more and a photoacid generator, the aromatic monomer having a vinyl group and an electron donating group other than the vinyl group, and the photoacid generator; and the composition is heated at 25°C and a shear rate of 200 (s -1 The photocurable composition for pattern reversal has a viscosity of 0.1 to 15 mPa·s when heated to 200° C.

2. The photocurable composition for pattern reversal according to claim 1, which does not contain water and organic solvent, or which contains water and / or organic solvent, and the total content of water and organic solvent is 5% by weight or less of the total amount of the photocurable composition.

3. The photocurable composition for pattern reversal according to claim 1 or 2, wherein the aromatic monomer is a compound represented by the following formula (1-1) and has a molecular weight of 120 or more. (In the formula, ring Z represents an aromatic hydrocarbon ring or a bonded ring in which two or more aromatic hydrocarbon rings are bonded via a single bond or a linking group; R 1 represents an electron donating group. n1 and n2 may be the same or different and represent an integer of 1 or more. Note that n1+n2 is an integer of 2 or more and 6 or less.

4. The photocurable composition for pattern reversal according to claim 1 or 2, wherein the total number of atoms, the number of carbon atoms, and the number of hydrogen atoms constituting one molecule of the aromatic monomer satisfy the following formula (A): (number of carbon atoms + number of hydrogen atoms) / total number of atoms ≧ 0.95 (A).

5. A method for manufacturing an electronic or optical device, comprising an etching mask manufacturing step, and an etching step of etching a workpiece using the etching mask obtained in the above step, the etching mask manufacturing step comprising the following steps 1, 2, and 3. Step 1: Providing a first resist film having a pattern on the surface of the workpiece; Step 2: Applying the photocurable composition for pattern reversal according to claim 1 or 2 onto the pattern of the first resist film provided on the surface of the workpiece, and photocuring; Step 3: Removing the pattern of the first resist film to obtain a second resist film made of a cured product of the photocurable composition and having a pattern that is an inverse of the concave-convex shape of the pattern of the first resist film, and using this as an etching mask.