Curable resin composition for silicon-containing resist, pattern forming method, method for producing imprint mold, and method for producing semiconductor device

Abstract

To provide a curable resin composition for a silicon-containing resist having good filling property and flattening property.SOLUTION: The present disclosure provides a curable resin composition for a silicon-containing resist comprising a polymerizable compound having a siloxane bond in a molecule and at least one polymerizable functional group, and a polymerization initiator, wherein a proportion of oxygen atoms bonded to a single silicon atom among oxygen atoms bonded to silicon atoms contained in the polymerizable compound is 10 mol% or less, and the curable resin composition for a silicon-containing resist has a viscosity of 20 cps or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a curable resin composition for a silicon-containing resist, a pattern formation method using the same, a method for producing an imprint mold, and a method for producing a semiconductor device. [Background technology]

[0002] Semiconductor devices and the like are typically fabricated by processing a substrate by dry etching using a patterned resist film as an etching mask. In recent years, there has been a demand for finer patterns. For example, pattern widths of less than 20 nm are required. To prevent pattern collapse in fine patterns, resist layers have been increasingly thinned. However, as resist layers become thinner, there are also trends toward deterioration of the cross-sectional shape of the resist layer and increased line edge roughness (LWR). As resist patterns become finer, the deterioration of resist pattern shape has become a problem due to a combination of the thinning of resist layers to prevent collapse and the various influences of the resist material. These influences include the diffusion of acid generated by exposure in the case of chemically amplified resists, the influence of reflected electrons in the case of electron beam (EB) resists, and shrinkage due to curing in the case of nanoimprint resists.

[0003] Given this background, inversion processes are sometimes used in current semiconductor miniaturization processes to form highly accurate fine patterns. In the inversion process, as shown in FIG. 5, a hard mask layer 52 is formed on a substrate 51 to be processed, and a pattern made of a conventional organic resist material is formed on the hard mask layer 52 as a core pattern 53 (FIG. 5(a)). An inversion layer 54 made of an inversion layer material is formed on the core pattern 53 (FIG. 5(b)). The core pattern 53 is removed by etching to form an inversion pattern 54p that has higher etching resistance than the core pattern (FIG. 5(c)). The hard mask layer 52 is etched using the inversion pattern 54p as a mask to form a hard mask pattern 52p (FIG. 5(d)). The substrate 51 is etched using the hard mask pattern 52p as a mask to obtain a patterned body 51p (FIG. 5(e)). The inversion layer material is typically a silicon-containing photocurable resin that has a sufficiently high etching selectivity with respect to the hard mask layer (see, for example, References 1 and 2). This method allows dry etching of a hard mask layer using a reverse pattern, which has higher etching resistance than a resist pattern made of a conventional organic resist material, as a mask, and also allows the selection of a wide variety of etching gases. Furthermore, since the pattern is reversed when the core pattern is formed, when a high-resolution pattern is drawn by electron beam lithography or the like, the drawing area can often be reduced, thereby shortening the construction period.

[0004] The above-mentioned Patent Documents 1 and 2 describe the manufacture of a mold using the above-mentioned pattern formation method. Patent Document 2 describes the formation of a flat inversion layer by applying a photocurable material containing silicon as an inversion layer material onto a resist pattern (core pattern) and curing the inversion layer material while pressing down a flat mold (flattening imprint). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5144127 [Patent Document 2] Japanese Patent Application Publication No. 2018-98470 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventionally, silicon-containing materials, particularly those with a siloxane skeleton, have been used as inversion layer materials to increase the etching selectivity. However, conventional materials with a siloxane skeleton have relatively high viscosity and may thicken during storage due to the curing reaction. As a result, as shown in Figure 5, when an inversion layer 54 is formed by applying the inversion layer material to a concave-convex structure 50 having a surface with a concave-convex structure X, the concaves (gaps between the core pattern 53) are not sufficiently filled, resulting in the formation of bubbles B, which cause defects after curing (Figure 5(b)). While dilution with a solvent can be considered to improve application performance, this can lead to problems such as the solvent floating to the surface during curing, impairing flatness, or causing poor curing. Using a film with such defects or poor flatness as an etching mask makes it difficult to accurately form fine patterns on the substrate being processed. Therefore, an inversion layer material with good filling and planarization properties is required.

[0007] There is also a technique for forming uneven shapes of different heights (depths) on a substrate (concave-convex structure) having an uneven surface. In this technique, a silicon-containing resist film is formed on the substrate having an uneven surface so as to cover the unevenness, and a pattern is formed on the silicon-containing resist film using an organic resist material. The silicon-containing resist film and the substrate are then etched using the organic resist pattern as a mask. Therefore, the silicon-containing resist film used to form such a multi-level uneven structure is also required to have good filling and planarizing properties for the substrate having an uneven surface.

[0008] The present disclosure has been made in view of the above circumstances, and a main object of the present disclosure is to provide a curable resin composition for a silicon-containing resist that has good filling properties and planarization properties. [Means for solving the problem]

[0009] The present disclosure provides a curable resin composition for a silicon-containing resist, comprising a polymerizable compound having a siloxane bond in its molecule and at least one polymerizable functional group, and a polymerization initiator, wherein the proportion of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to silicon atoms in the polymerizable compound is 10 mol % or less, the curable resin composition for a silicon-containing resist does not contain a solvent, and has a viscosity of 20 cPs or less.

[0010] The curable resin composition for silicon-containing resists of the present disclosure has a low viscosity of not more than the above-mentioned value. Furthermore, by ensuring that the proportion of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound is 10 mol % or less, thickening of the resin composition is suppressed. Therefore, the resin composition can be applied to a concave-convex structure with good filling properties while suppressing the generation of bubbles. Furthermore, since the resin composition is substantially solvent-free, it is possible to suppress the solvent from floating up to the surface during the curing process, thereby obtaining a cured layer with good flatness. Furthermore, since the resin composition contains silicon, it has good etching resistance to oxygen gas and chlorine gas.

[0011] In the above disclosure, the polymerizable compound preferably has a spherical structure. A polymerizable compound having a spherical structure can sufficiently reduce the viscosity of the curable resin composition for silicon-containing resists. Furthermore, a cured layer with high thermal stability can be obtained, suppressing thermal degradation during etching. Furthermore, the molecular weight after curing is homogenized, improving the linear error (LER).

[0012] In the above disclosure, the polymerizable compound preferably does not have an oxygen atom, a nitrogen atom, a phosphorus atom, or a sulfur atom between the silicon atom in the siloxane polymerized portion constituting the main skeleton of the spherical structure and the polymerizable functional group, because this improves etching resistance.

[0013] In the above disclosure, the cured product of the curable resin composition for silicon-containing resist preferably has an etching rate ratio of 1.0 or more to a standard resist when using fluorine gas, an etching rate ratio of 0.2 or less to a standard resist when using oxygen gas, and an etching rate ratio of 2.0 or less to a metal chromium layer when using chlorine gas. This is because having such etching characteristics enables the formation of fine patterns with high precision, particularly when used in a reversal process.

[0014] In the above disclosure, it is preferable that the contact angle with the surface of the standard resist is 20° or less. This improves wettability with resists made of organic materials, and allows for better filling of gaps in the core pattern (protrusions), especially when used in a reversal process.

[0015] Furthermore, the present disclosure provides a pattern formation method, which includes a coating step of coating a concave-convex structure having a concave-convex surface with the above-mentioned curable resin composition for a silicon-containing resist so as to cover the concave-convex structure, and etching the concave-convex structure using a cured layer of the curable resin composition for a silicon-containing resist. The curable resin composition for a silicon-containing resist of the present disclosure can be applied with good filling properties even in the concave-convex structure.

[0016] In the above disclosure, it is preferable to further include a planarization step in which the silicon-containing resist curable composition applied to the concave-convex structure is cured while being pressed against a flat mold from above to obtain the cured layer. The silicon-containing resist curable resin composition of the present disclosure can suppress the solvent from floating onto the surface during the planarization step, and a cured layer with good flatness can be obtained.

[0017] In the above disclosure, the concavo-convex structure preferably includes a substrate to be processed, a hard mask layer formed on the substrate to be processed, and a core pattern formed on the hard mask layer and made of an organic resist material, and after the planarization step, the method preferably includes the steps of: etching the core pattern to form a reverse pattern of the hardened layer complementary to the core pattern; etching the hard mask layer using the reverse pattern as a mask to form a hard mask pattern; and etching the substrate to be processed using the hard mask pattern as a mask. Such a reverse process makes it possible to form a fine pattern (e.g., dimension 20 nm or less) on the substrate to be processed with high precision.

[0018] In addition, in the above disclosure, it is preferable that the concavo-convex structure is a workpiece substrate having concaves and convexes on its surface, and that the method further comprises, after the planarization step, forming an organic resist pattern on the hardened layer, and etching the hardened layer and the workpiece substrate using the organic resist pattern as a mask. By using this method, a highly precise multi-level concavo-convex structure can be formed on the workpiece.

[0019] The present disclosure provides a method for manufacturing an imprint mold, which uses the above-described pattern formation method to manufacture an imprint mold.

[0020] The present disclosure provides a method for manufacturing a semiconductor device, which uses the above-described pattern formation method to manufacture a semiconductor device. [Effects of the Invention]

[0021] The present disclosure can provide a curable resin composition for a silicon-containing resist that has good filling properties and planarization properties for a concave-convex structure. [Brief explanation of the drawings]

[0022] [Figure 1]FIG. 1 is a schematic process diagram of a pattern formation method (first embodiment) using a curable resin composition for a silicon-containing resist according to the present disclosure. [Figure 2] FIG. 1 is a schematic process diagram of a pattern formation method (first embodiment) using a curable resin composition for a silicon-containing resist according to the present disclosure. [Figure 3] FIG. 2 is a schematic process diagram of a pattern formation method (second embodiment) using a curable resin composition for a silicon-containing resist according to the present disclosure. [Figure 4] FIG. 2 is a schematic process diagram of a pattern formation method (second embodiment) using a curable resin composition for a silicon-containing resist according to the present disclosure. [Figure 5] 1A to 1C are schematic cross-sectional views illustrating a pattern formation method using a conventional reversal process. [Figure 6] 1A to 1C are schematic process diagrams illustrating a method for manufacturing an imprint mold according to the present disclosure. [Figure 7] 1 is a microscopic photograph of a pattern formed on a substrate to be processed in an example. [Figure 8] 10 is a microscope photograph of a pattern formed on a substrate to be processed in a reference example. DETAILED DESCRIPTION OF THE INVENTION

[0023] Embodiments of the present disclosure will be described below with reference to the drawings and the like. However, the present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, to clarify the explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the actual form, but these are merely examples and are not intended to limit the interpretation of the present disclosure. Furthermore, in this specification and each drawing, elements similar to those previously described with reference to the preceding drawings will be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0024] In this specification, when describing a mode in which another component is placed on a certain component, the terms "above" or "below" are used, unless otherwise specified, to include both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween. Also, in this specification, when describing a mode in which another component is placed on the surface of a certain component, the terms "on the surface side" or "on the surface" are used, unless otherwise specified, to include both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween.

[0025] The curable resin composition for a silicon-containing resist, the pattern formation method, the imprint mold production method, and the semiconductor device production method of the present disclosure will be described in detail below.

[0026] A. Curable resin composition for silicon-containing resist As described above, materials having siloxane bonds in their molecules have been used as inversion layers in conventional inversion processes. Generally, such siloxane materials have relatively high viscosities. Furthermore, polymers having siloxane bonds in their molecules have oxygen atoms bonded to two silicon atoms. However, among the oxygen atoms, some oxygen atoms bonded to a single silicon atom are present, for example, at the terminals of the polymer. Such oxygen atoms typically constitute highly reactive functional groups, such as —OH or —OR (where R represents an alkyl group having 1 to 4 carbon atoms). The present inventors have newly discovered that the presence of such highly reactive functional groups causes a reaction during storage of a curable resin composition for imprints, resulting in a polymerizable compound with a high molecular weight, resulting in an increase in viscosity. It has also been found that the highly reactive functional groups of such polymerizable compounds chemically bond with the constituent material of the mold, such as quartz, resulting in stains that are difficult to remove by cleaning or the like.

[0027] The curable resin composition for silicon-containing resists according to the present disclosure comprises a polymerizable compound having a siloxane bond in its molecule and at least one polymerizable functional group, and a polymerization initiator; the ratio of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to silicon atoms in the polymerizable compound is 10 mol % or less; the curable resin composition for silicon-containing resists has a viscosity of 20 cPs or less; and is free of solvents.

[0028] 1 and 2 are schematic process diagrams illustrating an example of a pattern formation method for forming a pattern on a workpiece substrate by an inversion process using the curable resin composition for silicon-containing resists according to the present disclosure as an inversion layer material. As shown in Fig. 1, a concavo-convex structure 10 having a workpiece substrate 1, a hard mask layer 2 formed on the workpiece substrate, and a core pattern 3 (protrusions) composed of an organic resist material formed on the hard mask layer 2 is etched using the curable resin composition for silicon-containing resists as an inversion layer material to form a pattern on the workpiece substrate 1.

[0029] First, a curable resin composition 14 for a silicon-containing resist according to the present disclosure is applied to a concave-convex structure 10 having a surface with concave-convex patterns X1 so as to cover the concave-convex patterns X1 ( FIGS. 1(a) and 1(b), application step). Next, the curable resin composition 14 for a silicon-containing resist applied to the concave-convex structure is cured while a flat mold 5 is pressed against the concave-convex structure from above, to obtain a cured layer (reverse layer) 4 ( FIG. 1(c), planarization step). Next, after peeling off the flat mold 5, the cured layer 4 is etched to leave the cured layer 4 filling the gaps (concave portions) of the core pattern 3 (convex portions) ( FIG. 1(d)). Next, the core pattern 3 is removed by etching using the cured layer 4 filling the concave portions as a mask. By removing the core pattern 3, a cured layer pattern (reverse pattern) 4p complementary to the core pattern is formed on the hard mask layer 2 ( FIG. 2(e)). Using the hardened layer pattern 4p as a mask, the hard mask layer is etched to form a hard mask pattern 2p (FIG. 2(f)), and using the hard mask pattern 2p as a mask, the substrate 1 to be processed is etched to obtain a patterned body 1p (FIGS. 2(g) and 2(h)).

[0030] The curable resin composition for silicon-containing resists according to the present disclosure has low viscosity, and therefore can suppress the generation of bubbles when applied to a concave-convex structure. Furthermore, since it is substantially solvent-free, it can suppress the solvent from floating out onto the surface during the planarization process, and a cured layer with excellent flatness can be obtained. Furthermore, it can suppress poor curing due to the presence of a solvent. Furthermore, the curable resin composition for silicon-containing resists according to the present disclosure has good stability over time and can suppress thickening during storage. Furthermore, it can also suppress the reaction with the surface of the flat mold, as described below, and therefore has excellent releasability from the flat mold.

[0031] Thus, the silicon-containing resist curable resin composition of the present disclosure can provide a cured layer with excellent filling properties and flatness. Furthermore, because it contains silicon, it has excellent etching resistance against oxygen gas and chlorine gas. By using such a cured layer as an inversion layer in a reversal process, for example, it becomes possible to accurately form a fine pattern (e.g., dimensions of 20 nm or less) on a substrate to be processed.

[0032] The curable resin composition for silicon-containing resists (hereinafter sometimes simply referred to as the resin composition) of the present disclosure will be described in detail below.

[0033] 1.Viscosity The resin composition of the present disclosure has a viscosity of 20 cPs or less, preferably 10 cPs or less, and more preferably 7 cPs or less. On the other hand, although the lower limit is not particularly limited, it can be 1 cPs or more, and preferably 1.5 cPs or more. The resin composition of the present disclosure has an extremely low viscosity, allowing it to be applied to a concave-convex structure with good filling properties while suppressing the generation of air bubbles. Furthermore, such a low viscosity allows it to be applied using an inkjet method. In the present invention, the viscosity of the resin composition is measured at 25°C and 1000 (1 / s) when the resin composition is dropped onto a circular plate using an AR-G2 manufactured by TA Instruments in a measurement environment of 25°C and 40% RH, and a standard steel cone with a diameter of 40 mm is subjected to a shear rate of 10 to 1000 (1 / s).

[0034] 2.Polymerizable compound The polymerizable compound contained in the resin composition of the present disclosure has a siloxane bond in its molecule, has at least one polymerizable functional group, and has 10 mol% or less of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to the silicon atoms contained therein. The polymerizable compound of the present disclosure can be a polymer or oligomer having a tetrafunctional silane, trifunctional silane, bifunctional silane, or monofunctional silane as a structural unit, either alone or in combination.

[0035] In the present disclosure, it is preferable to use a resin composition containing mainly trifunctional silanes and difunctional silanes as structural units, depending on the desired properties of the resin composition, such as etching resistance, viscosity, etc. Furthermore, for the purpose of improving etching resistance, etc., a tetrafunctional silane may be contained.

[0036] The polymerizable compound used in the present disclosure is characterized in that, among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound, the proportion of oxygen atoms bonded to a single silicon atom is 10 mol % or less, preferably 7 mol % or less, and particularly preferably 5 mol % or less.

[0037] Here, the oxygen atom bonded to a single silicon atom means an oxygen atom in which one of the two halves of the oxygen atom is bonded to silicon, but not an oxygen atom in which both halves of the oxygen atom are bonded to silicon atoms. The other halves of the oxygen atom are not particularly limited as long as they are bonded to something other than silicon, but are preferably bonded to hydrogen or an alkyl group having 1 to 4 carbon atoms.

[0038] In the present disclosure, by ensuring that the proportion of oxygen atoms bonded to a single silicon atom, i.e., the proportion of highly reactive functional groups such as -OH or -OR (R represents an alkyl group having 1 to 4 carbon atoms) bonded to silicon atoms, falls within the above range, the stability over time of the resin composition can be improved and thickening during storage can be suppressed. For the same reason, the reaction with the surface of the flat mold, which will be described later, can also be suppressed, resulting in excellent releasability from the flat mold.

[0039] The reason why such highly reactive functional groups as described above are present in a certain proportion in the polymerizable compound is presumably due to unreacted oxygen atoms remaining in the production process of the polymerizable compound. The reason why such unreacted oxygen atoms remain is thought to be that in the case of -OR (R represents an alkyl group having 1 to 4 carbon atoms), hydrolysis of the alkoxy group in the raw material has not progressed, and in the case of -OH, it is thought to be because the polymerization reaction has not progressed completely due to steric hindrance, etc.

[0040] In the present disclosure, the ratio of oxygen atoms bonded to a single silicon atom refers to the number of oxygen atoms bonded to a single silicon atom, assuming that the number of oxygen atoms bonded to silicon atoms in the polymerizable compound is 100. The method for measuring this ratio is: 29 It can be calculated by analyzing the spectrum by Si NMR.

[0041] Specifically, when a composition containing a siloxane structure having a trifunctional silane as a building block is analyzed by NMR, a component T in which none of the three oxygen atoms bonded to the silicon atom are bonded to other silicon atoms is identified. 0 , component T in which one of the three oxygen atoms bonded to a silicon atom is bonded to another silicon atom 1 , component T in which two of the three oxygen atoms bonded to a silicon atom are bonded to other silicon atoms 2 , and component T in which all three oxygen atoms bonded to a silicon atom are bonded to other silicon atoms. 3 Four peaks are observed.

[0042] These four peaks (T 0 ~Τ 3 ) is the integral of the area ratio, T 0 ~T 3 In this case, the proportion (mol %) of oxygen atoms bonded to the single silicon atom can be calculated from the following formula (1).

[0043] (T 0 ×3+T 1 ×2+T 2 x1+T 3 ×0) / ((T 0 +T 1 +T 2 +T 3 )×3)×100 (1)

[0044] Furthermore, when the composition contains a siloxane structure having a bifunctional silane as a constituent unit, three peaks are observed: a component in which none of the two oxygen atoms bonded to the silicon atom are bonded to another silicon atom, a component in which one of the two oxygen atoms bonded to the silicon atom is bonded to another silicon atom, and a component in which all of the two oxygen atoms bonded to the silicon atom are bonded to another silicon atom.

[0045] The integral of these three peaks, that is, the ratio of their areas, is called D 0 ~D 2In this case, the proportion (mol %) of oxygen atoms bonded to the single silicon atom can be calculated from the following formula (2).

[0046] (D 0 ×2+D 1 ×1+D 2 ×0) / ((D 0 +D 1 +D 2 )×2)×100 (2)

[0047] Furthermore, when the composition contains a siloxane structure having a tetrafunctional silane as a constituent unit, five peaks are observed: a component in which none of the four oxygen atoms bonded to the silicon atom are bonded to other silicon atoms; a component in which one of the four oxygen atoms bonded to the silicon atom is bonded to other silicon atoms; a component in which two of the four oxygen atoms bonded to the silicon atom are bonded to other silicon atoms; a component in which three of the four oxygen atoms bonded to the silicon atom are bonded to other silicon atoms; and a component in which all of the four oxygen atoms bonded to the silicon atom are bonded to other silicon atoms.

[0048] The integral of these five peaks, i.e., the ratio of their areas, is called Q 0 ~Q 4 In this case, the proportion (mol %) of oxygen atoms bonded to a single silicon atom can be calculated from the following formula (3).

[0049] (Q 0 ×4+Q 1 ×3+Q 2 ×2+Q 3 ×1+Q 4 ×0) / ((Q 0 +Q 1 +Q 2 +Q 3 +Q 4 )×4)×100 (3)

[0050] For example, when the polymerizable compound having two types of constituent units, a trifunctional silane and a bifunctional silane, is contained in the resin composition, ((T 0 ×3+T1 ×2+T 2 x1+T 3 ×0)+(D 0 ×2+D 1 ×1+D 2 ×0)) / ((T 0 +T 1 +T 2 +T 3 )×3+(D 0 +D 1 +D 2 )×2)×100 It is calculated as follows. the above 29 The values ​​calculated by performing Si NMR spectrum analysis on the resin composition of the present disclosure will be used.

[0051] The weight average molecular weight of the polymerizable compound is preferably in the range of 500 to 100,000, particularly in the range of 600 to 50,000, and more particularly in the range of 700 to 20,000.

[0052] The weight average molecular weight (Mw) is a polystyrene-equivalent molecular weight measured by gel permeation chromatography (GPC), and is a value measured under the following conditions after pressure filtration through a membrane filter with a pore size of 0.2 μm.

[0053] (conditions) Equipment: Water 2695 Sample amount: Approximately 10 mg of sample per 3 mL of solvent ·Injection volume: 5μL Guard column: LF-G (Shodex) Column: GPC LF-804 x 3 (Shodex) Column temperature: 40℃ Mobile phase: Tetrahydrofuran ·Flow rate: 1.0mL / min Detector: Differential refractometer (Water 2414) Molecular weight calibration: Polystyrene equivalent

[0054] The polymerizable functional group possessed by the polymerizable compound is not particularly limited as long as it is a functional group capable of undergoing a polymerization reaction and the polymerization reaction proceeds in response to an external stimulus, and examples thereof include an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an epoxy group, an oxetane group, a vinyl ether group, etc., which undergo a polymerization reaction in response to light irradiation, heat, heat accompanying light irradiation, the action of a photoacid generator, etc. This is because such polymerizable functional groups have good stability during synthesis and storage, good reactivity during curing, and are easy to obtain as raw materials.

[0055] In the present disclosure, acryloyl groups and methacryloyl groups are particularly preferred due to their curing speed and wide range of physical property options.

[0056] When the polymerizable group directly bonded to the silicon atom in the polymerizable compound is bulky, steric hindrance may change the reactivity, affecting curability, etc. In consideration of this, the molecular weight of the polymerizable group directly bonded to the silicon atom is preferably in the range of 20 to 500, and more preferably in the range of 25 to 400. In the present disclosure, the polymerizable group refers to a group containing a polymerizable functional group. As such a polymerizable group, preferred examples include the structures shown below.

[0057] [ka] (Here, R1 represents a substituted or unsubstituted alkyl chain having 1 to 10 carbon atoms, and R2 represents a substituted or unsubstituted alkyl chain having 1 to 3 carbon atoms or a hydrogen atom. Both R1 and R2 may be linear or branched.) At least one polymerizable functional group may be bonded to the structural unit of the polymerizable compound, but this is not limitative, and two or more polymerizable functional groups may be bonded.

[0058] As a structural unit having a polymerizable group of the polymerizable compound used in the present disclosure, the following can be given as preferred examples.

[0059] First, examples of trifunctional silanes include 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-ethyl-3-[3'-(trimethoxysilyl)propyl]methyloxetane, 3-ethyl-3-[3'-(triethoxy ... ]methyloxetane, and the like can be mentioned, among which 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-ethyl-3-[3'-(trimethoxysilyl)propyl]methyloxetane, 3-ethyl-3-[3'-(triethoxysilyl)propyl]methyloxetane, and the like can be preferably used.

[0060] Examples of bifunctional silanes include 3-acryloxypropyl(methyl)dimethoxysilane, 3-acryloxypropyl(methyl)diethoxysilane, 3-methacryloxypropyl(methyl)dimethoxysilane, 3-methacryloxypropyl(methyl)diethoxysilane, vinyl(methyl)dimethoxysilane, vinyl(methyl)diethoxysilane, allyl(methyl)dimethoxysilane, allyl(methyl)diethoxysilane, and styryl(methyl)dimethoxysilane. Silane, styryl(methyl)diethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)diethoxysilane, 3-ethyl-3-[3'-(methyldimethoxysilyl)propyl]methyloxetane, 3-ethyl-3-[3'-(methyldiethoxysilyl) Examples of suitable alkyl silanes include 3-acryloxypropyl(methyl)dimethoxysilane, 3-acryloxypropyl(methyl)diethoxysilane, 3-methacryloxypropyl(methyl)dimethoxysilane, 3-methacryloxypropyl(methyl)diethoxysilane, vinyl(methyl)dimethoxysilane, vinyl(methyl)diethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)diethoxysilane, 3-ethyl-3-[3'-(methyldimethoxysilyl)propyl]methyloxetane, and 3-ethyl-3-[3'-(methyldiethoxysilyl)propyl]methyloxetane.

[0061] Furthermore, a structural unit having a polymerizable group can be used in combination with a structural unit having no polymerizable group. Examples of trifunctional structural units having no polymerizable group include trimethoxy(methyl)silane, triethoxy(methyl)silane, methyltrippropoxysilane, tributoxy(methyl)silane, methyltriphenoxysilane, ethyltrimethoxysilane, triethoxy(ethyl)silane, ethyltrippropoxysilane, tributoxy(ethyl)silane, ethyltriphenoxysilane, trimethoxy(propyl)silane, triethoxy(propyl)silane, tripropoxy(propyl)silane, tributoxy(propyl)silane, triphenoxy(propyl)silane, butyltrimethoxysilane, butyltriethoxysilane, butyltrippropoxysilane, tributoxy(butyl)silane, and butyltriphenoxysilane. Silane, trimethoxy(phenyl)silane, triethoxy(phenyl)silane, phenyltripropoxysilane, tributoxy(phenyl)silane, triphenoxy(phenyl)silane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, cyclohexyltripropoxysilane, cyclohexyltributoxysilane, cyclohexyltriphenoxysilane, and the like can be used. Among these, trimethoxy(methyl)silane, triethoxy(methyl)silane, ethyltrimethoxysilane, triethoxy(ethyl)silane, trimethoxy(phenyl)silane, triethoxy(phenyl)silane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, and the like can be preferably used.

[0062] Furthermore, examples of bifunctional silanes that can be preferably used include dimethoxydimethylsilane, diethoxydimethylsilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, cyclohexyl(dimethoxy)methylsilane, cyclohexyldiethoxymethylsilane, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxymethylvinylsilane, and diethoxymethylvinylsilane.

[0063] The polymerizable compound according to the present disclosure preferably has a silicon atom content of 15% by mass or more, particularly preferably 20% by mass or more, in the polymerizable compound. This silicon atom content improves the etching resistance with oxygen gas or chlorine gas, and allows for excellent etching properties.

[0064] As described above, the polymerizable compound in the present disclosure has a siloxane bond in the molecule, at least one polymerizable functional group, and the structure is not limited as long as the proportion of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound is 10 mol% or less. However, (a) polymerizable compounds having a spherical structure and (b) polyhedral siloxane oligomers having an incompletely condensed skeleton, as described below, are preferred because they can sufficiently reduce the viscosity even in resin compositions that are substantially free of solvents as disclosed in the present disclosure. In particular, (a) polymerizable compounds having a spherical structure are preferred in terms of thermal stability, processing uniformity, etc.

[0065] (a) Polymerizable compound having a spherical structure A spherical structure is a structure in which polymerizable functional groups extend outward from a polymerized portion with a high degree of polymerization. For example, a polymerizable compound with a spherical structure, such as a dendrimer, has a ratio of oxygen atoms bonded to a single silicon atom of 10 mol% or less among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound, and can also sufficiently reduce the viscosity of the resin composition. Furthermore, polymerizable compounds with a spherical structure have high thermal stability and can suppress deterioration during etching. Furthermore, the spherical structure homogenizes the molecular weight after curing, improving processing uniformity and LER.

[0066] Examples of polymerizable compounds having a spherical structure include those containing trifunctional silane as a constituent unit. Among these, those containing only trifunctional silane as a constituent unit are preferred. Examples of polymerizable compounds having such a spherical structure include one or a mixture of two or more hexamers to 36amers (molecular weight 1000 or more and 6300 or less) of trifunctional silanes having polymerizable functional groups. The molecular weight of the polymerizable compound having a spherical structure may be in the range of 2000 or more and 6000 or less, and preferably in the range of 2000 or more and 3000 or less.

[0067] In the case of siloxanes consisting of trifunctional silanes, SiO 3 / 2 The polymerizable compound has a structure in which polymerizable functional groups extend outward from a siloxane polymerization part consisting of units with a high degree of siloxane polymerization. In such a polymerizable compound with a spherical structure, the degree of siloxane polymerization in the siloxane polymerization part can be made higher than 90%, particularly 95% or higher, and even 97% or higher, so that the proportion of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound is 10 mol % or less.

[0068] This is presumably due to the following reason: When the hydrolysis reaction of trifunctional silane is carried out under basic conditions, OH groups are formed on Si atoms. - A nucleophilic reaction occurs. As one hydrolyzable group (alkoxy group) is hydrolyzed, the steric hindrance of the Si atom decreases, increasing the hydrolysis reaction rate, and all three hydrolyzable groups (alkoxy groups) are hydrolyzed to produce -Si(OH)3. Since all OH groups in -Si(OH)3 are capable of condensation polymerization, a three-dimensional siloxane structure with high density and high degree of polymerization is formed.

[0069] Specifically, it has a spherical structure represented by the following formula: The following formula is a schematic diagram showing a polymerizable compound having a spherical structure, which is composed of an octamer of trifunctional silanes having an acryloxypropyl group and a 3-methacryloxypropyl group as the polymerizable group.

[0070] [ka] (In the formula, SiO 1.5 is SiO 3 / 2 It represents a siloxane polymerized part consisting of units.

[0071] In the present disclosure, the polymerizable compound having the spherical structure preferably has a silicon atom (e.g., SiO ) in the siloxane polymerized portion constituting the main skeleton of the spherical structure in the bonding group between the siloxane polymerized portion constituting the main skeleton of the spherical structure and the polymerizable functional group. 3 / 2 Preferably, there are no oxygen atoms, nitrogen atoms, phosphorus atoms, or sulfur atoms between the silicon atom of the unit and the polymerizable functional group. If there are oxygen atoms, nitrogen atoms, phosphorus atoms, or sulfur atoms in such locations, the polymerizable functional group is easily etched by the oxygen gas and chlorine gas used in dry etching. If there are no oxygen atoms, nitrogen atoms, phosphorus atoms, or sulfur atoms, a sufficient selectivity can be obtained with an organic resist material or a hard mask layer (e.g., metallic chromium) during dry etching with oxygen gas or chlorine gas. The bonding group between the silicon atom and the polymerizable functional group in the siloxane polymerization moiety is, for example, a divalent hydrocarbon group that does not contain an oxygen atom, a nitrogen atom, a phosphorus atom, or a sulfur atom, preferably a linear alkylene group, more preferably -(CH2) n - (n is an integer from 1 to 9).

[0072] The polymerizable compound having a spherical structure can be obtained by subjecting a hydrolyzable silane composition containing at least a hydrolyzable silane to a hydrolysis and condensation reaction under basic conditions.

[0073] Specifically, the reaction can be carried out by placing a solvent and the silane raw material in a reactor, adding a basic catalyst, and then adding water dropwise while stirring. Examples of basic catalysts include sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate (K2CO3), sodium carbonate, and ammonia. The reaction can be carried out at a pH of 8 to 13, typically at room temperature to 100°C.

[0074] The silane used as the raw material may be one or more of tetrafunctional hydrolyzable silane, trifunctional hydrolyzable silane, bifunctional hydrolyzable silane, and monofunctional hydrolyzable silane, but it is preferable to use tetrafunctional hydrolyzable silane or trifunctional hydrolyzable silane, especially trifunctional hydrolyzable silane. Furthermore, only one type of hydrolyzable silane may be used, or two or more types may be used in combination.

[0075] By using a basic catalyst in the synthesis step, the polymerizable compound obtained by the hydrolysis and condensation reaction has a high degree of condensation, and therefore it is possible to easily obtain a polymerizable compound having a spherical structure in which the proportion of oxygen atoms bonded to a single silicon atom is reduced, particularly to 10 mol % or less, among the oxygen atoms bonded to silicon atoms.

[0076] (b) Polyhedral siloxane oligomers with incompletely condensed backbones In addition, in the present disclosure, the polymerizable compound is preferably a polyhedral siloxane oligomer having an incompletely condensed skeleton. Because such a polymerizable compound has a regular structure, the proportion of oxygen atoms bonded to a single silicon atom among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound is 10 mol % or less. In addition, the viscosity of the resin composition can be sufficiently reduced.

[0077] The polyhedral siloxane oligomer having an incompletely condensed skeleton to which polymerizable functional groups are bonded may be an incompletely condensed type polyhedral siloxane oligomer having a completely condensed skeleton, in which one vertex, one side, or one face is missing.The polyhedral siloxane oligomer having an incompletely condensed skeleton to which polymerizable functional groups are bonded is particularly preferably one represented by the following formula:

[0078] [ka] (In the formula, R 3 is a monovalent hydrocarbon group, and R4 is a -Si-polymerizable group bonded to an oxygen atom in the formula, a hydrogen atom, a metal ion such as Na or Li, or a tetraalkylammonium ion (the alkyl group is methyl, ethyl, propyl, butyl, etc.). R 3 is a monovalent hydrocarbon group, preferably an alkyl group having 1 to 5 carbon atoms, or a phenyl group, specifically an ethyl group, a butyl group, or a phenyl group.

[0079] The polymerizable compound can be obtained by reacting a polyhedral siloxane oligomer having an incompletely condensed skeleton in which a hydrogen atom, a hydroxy group, or an organic group other than a polymerizable functional group is bonded to a silicon atom, with a polymerizable functional group-containing compound.

[0080] The starting polyhedral siloxane oligomer having an incompletely condensed skeleton has a silicon atom at its vertex bonded to a hydrogen atom, a hydroxyl group, or an organic group other than a polymerizable functional group.

[0081] Examples of organic groups other than the polymerizable functional group include an alkoxy group, an alkyl group, and a phenyl group.

[0082] The reaction between the raw material and the polymerizable functional group-containing compound may be a conventional reaction, such as an addition reaction between a hydrogen atom directly bonded to silicon and a polymerizable functional group-containing compound having an unsaturated double bond, or a reaction between an OH group or OR group directly bonded to silicon and a polymerizable functional group-containing compound capable of forming a siloxane bond.

[0083] The content of the polymerizable compound in the resin composition is not particularly limited, but from the viewpoint of making the viscosity of the resin composition equal to or less than the above value, it is preferably more than 0 mass % and equal to or less than 50 mass %, and particularly preferably 10 mass % or more and 30 mass % or less in the resin composition.

[0084] 3. Polymerization initiator The resin composition according to the present disclosure contains a polymerization initiator. Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator, with a photopolymerization initiator being particularly preferred.

[0085] A photopolymerization initiator is a substance that generates reactive species that cause a polymerization reaction of a polymerizable compound when stimulated by light. Specific examples include photoradical generators that generate radicals when stimulated by light, and photoacid generators that generate protons when stimulated by light. A photoradical generator is a polymerization initiator that generates radicals when stimulated by light (radiation such as infrared light, visible light, ultraviolet light, far ultraviolet light, charged particle rays such as X-rays and electron beams), and is mainly used when the polymerizable compound is a radically polymerizable compound. On the other hand, a photoacid generator is a polymerization initiator that generates acid (protons) when stimulated by light, and is mainly used when the polymerizable compound is a cationically polymerizable compound.

[0086] Examples of photoradical generators include, but are not limited to, 2,4,6-trimethyldiphenylphosphine oxide, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, etc. These photoradical generators may be used alone or in combination of two or more.

[0087] Examples of photoacid generators include, but are not limited to, onium salt compounds, sulfone compounds, sulfonate ester compounds, sulfonimide compounds, and diazomethane compounds.

[0088] The thermal polymerization initiator is a compound that generates the above-mentioned polymerization factors (radicals, cations, etc.) by heat. Specifically, the thermal polymerization initiator includes a thermal radical generator that generates radicals by heat, a compound that generates protons (H + Thermal radical generators are mainly used when the polymerizable compound is a radical polymerizable compound. On the other hand, thermal acid generators are mainly used when the polymerizable compound is a cationically polymerizable compound.

[0089] Examples of thermal radical generators include organic peroxides and azo compounds. Examples of organic peroxides include peroxyesters such as t-hexylperoxyisopropyl monocarbonate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxyisopropyl carbonate; peroxyketals such as 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane; and diacyl peroxides such as lauroyl peroxide, but are not limited thereto. Examples of azo compounds include azonitriles such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 1,1'-azobis(cyclohexane-1-carbonitrile), but are not limited thereto.

[0090] Examples of thermal acid generators include known iodonium salts, sulfonium salts, phosphonium salts, ferrocenes, etc. Specific examples include, but are not limited to, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium hexafluoroborate.

[0091] The content of the polymerization initiator in the resin composition of the present disclosure is not particularly limited, and can be in the range of 0.5% by mass to 20% by mass, and more particularly, in the range of 1% by mass to 10% by mass, relative to the polymerizable compound.

[0092] 4. Solvent The resin composition of the present disclosure is substantially free of solvent. By being substantially free of solvent, deterioration of flatness and poor curing caused by the solvent floating to the surface during curing can be suppressed. Here, "substantially free of solvent" means that the resin composition does not contain any solvent other than impurities or other solvents that are unintentionally contained. For example, the solvent content of the resin composition in the present disclosure is preferably 0.01% by mass or less, and more preferably 0.001% by mass or less, based on the total resin composition. The solvent referred to here refers to a solvent commonly used in curable compositions and photoresists. The type of solvent is not particularly limited, as long as it dissolves and uniformly disperses the compound used in the present invention and does not react with the compound.

[0093] 5.Optional ingredients (1) Reactive crosslinking agent The resin composition of the present disclosure may further contain a reactive crosslinking agent. The reactive crosslinking agent has a polymerizable functional group, for example, one having two or more polymerizable functional groups. Examples of the polymerizable functional group include an ethylenically unsaturated bond-containing group and an epoxy group, with the ethylenically unsaturated bond-containing group being preferred. Examples of the ethylenically unsaturated bond-containing group include a (meth)acrylic group and a vinyl group, with the (meth)acrylic group being more preferred and the acrylic group being even more preferred. Furthermore, the (meth)acrylic group is preferably a (meth)acryloyloxy group. One molecule may contain two or more types of polymerizable groups, or may contain two or more of the same type of polymerizable group.

[0094] Examples of photopolymerizable monomers (bifunctional monomers) having two polymerizable functional groups include trimethylolpropane di(meth)acrylate, ethylene 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, and bis(hydroxymethyl)tricyclodecane di(meth)acrylate. Commercially available bifunctional monomers include Light Acrylate 3EG-A, 4EG-A, 9EG-A, NP-A, DCP-A, BP-4EAL, and BP-4PA (all manufactured by Kyoeisha Chemical Co., Ltd.). In addition, from the viewpoint of compatibility, polyfunctional monomers having a siloxane structure are preferred.

[0095] The content of the reactive crosslinking agent is not particularly limited, and can be within a range of 0 to 99% by mass in the resin composition of the present disclosure, and is preferably within a range of 5 to 80% by mass.

[0096] (2) Other The resin composition of the present disclosure may contain other components in addition to the polymerizable compound, polymerization initiator, and reactive crosslinker described above. Examples of other components include, as needed, surfactants, release agents, silane coupling agents, photosensitizers, antioxidants, organometallic coupling agents, polymerization inhibitors, UV absorbers, light stabilizers, antiaging agents, plasticizers, adhesion promoters, photobase generators, colorants, elastomer particles, photoacid amplifiers, basic compounds, and other components such as flow modifiers, antifoaming agents, and dispersants. To achieve good etching properties, it is preferable that the resin composition does not contain any components other than the polymerizable compound, polymerization initiator, and reactive crosslinker described above. However, even if the other components are contained, the content of the other components is preferably 5% by mass or less, and particularly preferably 3% by mass or less, of the resin composition of the present disclosure.

[0097] 6. Other physical properties (1) Wettability The resin composition of the present disclosure preferably exhibits a contact angle with the surface of a standard resist of 20° or less, more preferably 15° or less. Specifically, in the present disclosure, the contact angle can be measured 5 seconds later using a contact angle measuring device (Kyowa Interface Science Co., Ltd., automatic contact angle meter DM-501) by dropping the resin composition of the present disclosure onto the surface of a standard resist layer in atmospheric air at a temperature of 25°C and a humidity of 33%.

[0098] In the present disclosure, the standard resist layer is formed using an acrylic-styrene copolymer (organic resist resin) as the base resin.

[0099] If the resin composition has the above-described contact angle with respect to the standard resist layer, when used as a reversal layer material in a reversal process, for example, the resist composition will have good wettability with respect to the core pattern formed from the resist composition, allowing for better filling and application. When the resin composition of the present disclosure exhibits the above-described contact angle with respect to the standard resist, it will exhibit good wettability even if the composition of the organic resist material actually used for the core pattern differs from the composition of the standard resist.

[0100] (2) Etching characteristics The inversion process shown in Figure 1 includes etching steps for the hardening layer 4, core pattern 3, hard mask layer 2, and workpiece substrate 1. Among these, etching involving the hardening layer involves etching the hardening layer, core pattern, and hard mask layer, and different etching gases are used for each step. For example, fluorine gas is used as the etching gas for etching the hardening layer, oxygen gas is used for etching the core pattern, and chlorine gas is used for etching the hard mask layer.

[0101] The cured product (cured layer) of the resin composition of the present disclosure preferably has an etching rate ratio (cured product / standard resist) of 1.0 or more relative to a standard resist when using fluorine gas. Furthermore, the etching rate ratio (cured product / standard resist) relative to a standard resist when using oxygen gas is preferably 0.2 or less. Furthermore, the etching rate ratio (cured product / metallic chromium) relative to a metal chromium layer when using chlorine gas is preferably 2.0 or less. Such an etching rate ratio allows the resist to exhibit good etching resistance during etching of the core pattern (organic resist material) and the hard mask layer (e.g., a metal chromium layer) in a reversal process, while exhibiting a sufficiently high etching rate for the core pattern during etching of the hardened layer, thereby enabling highly accurate formation of fine patterns when used in a reversal process.

[0102] The above etching rate ratio is a value calculated from the etching depth of the hardened layer, standard resist layer, and metal chromium layer under the following etching conditions. The standard resist is the same as that described above in "6. Other physical properties (1) Wettability." (Fluorine gas etching conditions) CF4 gas flow rate: 30 sccm, He gas flow rate: 70 sccm ICP power: 300W, RIE power: 100W, pressure: 1.0Pa (Oxygen gas etching conditions) O2 gas flow rate: 100sccm, ICP power: 100W, RIE power: 50W, pressure: 1.0Pa (Chlorine gas etching conditions) Cl2 gas flow rate: 30 sccm, He gas flow rate: 70 sccm ICP power: 300W, RIE power: 5W, pressure: 1.0Pa

[0103] The effect of the etching rate ratio to the metal chromium layer using the above chlorine gas is fully exhibited when the ratio of the metal layer thickness to the hardened layer thickness is in the range of 1:10 to 1:50.

[0104] (3) Surface free energy The resin composition of the present disclosure has a surface free energy of 30 mJ / m 2 More than 70mJ / m 2 It is preferable that the concentration is not more than 30 mJ / m 2 More than 50mJ / m 2 Within the above range, for example, compatibility with the core pattern made of an organic resist material can be suppressed, and the resin can be sufficiently wetted and spread over the core pattern, which is preferable.

[0105] (4) Glass transition temperature The cured product of the resin composition according to the present disclosure preferably has a glass transition temperature (Tg) of 50° C. or higher, more preferably 80° C. or higher. Such a glass transition temperature provides high thermal stability and can suppress deterioration due to heat generated during etching.

[0106] (5) Dynamic viscoelasticity measurement The cured product of the resin composition of the present disclosure has a storage modulus of E' = 1.0 × 10 at 25°C. 9 Pa or more, and E'=3.0×10 at 150°C. 8 The loss modulus at 25°C is preferably E" = 8.9 x 10 Pa or more. 7 Pa or more, and E" = 1.7 x 10 at 150°C. 7 The upper limit of the storage modulus (at 25°C) is usually 1.0 x 10 11 The above value is obtained by applying 365 nm ultraviolet light to the resin composition of the present disclosure in an oxygen-free atmosphere at 1 J / cm2. 2 These are values ​​obtained by measuring the dynamic viscoelasticity of the cured product after irradiation. The storage modulus (E') and loss modulus (E") can be measured in accordance with JIS K7244 using a Rheogel E-4000 manufactured by UBM Corporation. Typically, the storage modulus E' and loss modulus E" of a plastic material decrease at temperatures equal to or higher than the glass transition temperature Tg. The cured product of the resin composition of the present disclosure exhibits little change in modulus even at high temperatures equal to or higher than the glass transition temperature, has high thermal stability, and is able to retain, for example, a pattern shape.

[0107] (6) Elastic deformation power A cured product of the resin composition according to the present disclosure (particularly a composition containing the polymerizable compound having the spherical structure) can have an elastic deformation power of 50% or more at room temperature (25°C). The closer the elastic deformation power is to 100%, the easier it is to elastically deform. Because the cured product of the resin composition according to the present disclosure can exhibit the above-described property of being easily elastically deformable, for example, when a resist pattern is formed by imprinting using the resin composition according to the present disclosure, a resist pattern can be formed that has the property of returning (restoring) a tilted or collapsed pattern to its original state. Note that, in the present disclosure, the elastic deformation power can be calculated from the load-displacement curve obtained by performing a vertical indentation test using a nanoindenter (Fisher Instruments HM500) under the following measurement conditions using the following equation: Total deformation work = Elastic deformation work + Plastic deformation work Elastic deformation work rate (%) = (elastic deformation work / total deformation work) x 100 (Measurement conditions) Maximum pressing load: 1.0mN

[0108] (7) Refractive index The refractive index of the cured product of the resin composition of the present disclosure is not particularly limited, but is preferably 1.40 to 1.60, and more preferably 1.45 to 1.55. Furthermore, the refractive index difference from the standard resist is preferably 0.05 or more, more preferably 0.07 or more. If the refractive index difference from the standard resist is equal to or greater than the above value, in the reversal process, in the step of etching the cured layer 4 so as to leave the cured layer 4 filling the gaps in the core material pattern 3 (protrusions) (FIG. 1(d)), it becomes easy to determine using a monitoring microscope or optical interference film thickness meter that the top of the core material pattern 3 is exposed, and etching of the core material pattern 3 in the next step can be easily performed.

[0109] 7.Applications The use of the curable resin composition for silicon-containing resists of the present disclosure is not particularly limited, but it can be used for applications such as applying it to a concave-convex structure having an uneven surface to form a flat layer, and after curing, it can be used for etching. Specifically, it is preferably used in "B. Pattern formation method," "C. Imprint mold manufacturing method," and "D. Semiconductor device manufacturing method," which will be described later.

[0110] B. Pattern Formation Method The pattern formation method according to the present disclosure will be described with reference to the drawings. The pattern formation method according to the present disclosure is a pattern formation method in which a pattern is formed on a substrate to be processed using the above-described curable resin composition for a silicon-containing resist. As described above, the resin composition according to the present disclosure has excellent filling properties and planarization properties for a concave-convex structure. Therefore, it is particularly suitable for use in the following pattern formation method by a reversal process (first embodiment) and the pattern formation method for a multi-stage concave-convex structure (second embodiment).

[0111] 1. Pattern formation method by reversal process (first embodiment) 1 and 2 are schematic process diagrams showing an example of a pattern formation method according to the present disclosure using an inversion process. A composite of a substrate to be processed 1, a hard mask layer 2 formed on the substrate to be processed, and a core pattern 3 formed on the hard mask layer 2 is used as a concavo-convex structure 10 having a concavo-convex structure X1 on its surface, and the above-mentioned curable resin composition for silicon-containing resist is used as an inversion layer material to form a pattern on the substrate to be processed 1.

[0112] (1) Coating process The pattern formation method of the present disclosure includes a coating step of coating a curable resin composition 14 for silicon-containing resists onto a concave-convex structure 10 having concave-convex surfaces X1 so as to cover the concave-convex surfaces X1 (FIGS. 1(a) and 1(b)). The resin composition of the present disclosure has low viscosity, which prevents the generation of bubbles when applied onto the concave-convex structure, allowing the composition to be applied with good filling properties.

[0113] As shown in Figures 1 and 2, a concave-convex structure 10 can be used, which has a substrate 1 to be processed, a hard mask layer 2 formed on the substrate to be processed, and a core pattern 3 (convex portion) formed on the hard mask layer 2.

[0114] Examples of the substrate to be processed include substrates to be processed for imprint molds and semiconductor devices.

[0115] For example, when the purpose of pattern formation is the manufacture of an imprint mold, an appropriate material can be selected as the substrate of the imprint mold. Specifically, when the resist used in imprinting using the imprint mold to be manufactured is photocurable, a material that is transparent to the irradiated light for curing the resist can be used. For example, glasses such as quartz glass, silicate glass, calcium fluoride, magnesium fluoride, and acrylic glass, as well as sapphire, gallium nitride, and resins such as polycarbonate, polystyrene, acrylic, and polypropylene, or any laminate material thereof can be used. Furthermore, when the resist used is not photocurable or when light for curing the resist can be irradiated from the pattern-forming substrate side used in imprinting, the substrate to be processed does not need to be optically transparent. In addition to the above materials, for example, metals such as silicon, nickel, titanium, and aluminum, as well as alloys, oxides, nitrides, and any laminate material thereof can be used.

[0116] Furthermore, when the purpose of pattern formation is to manufacture semiconductor elements, fine wiring, etc., the substrate to be processed can be made of metals such as silicon, nickel, titanium, aluminum, etc., or alloys, oxides, nitrides, or any laminates thereof. Furthermore, the material of the substrate to be processed can be appropriately selected depending on the purpose of pattern formation.

[0117] The hard mask layer formed on the substrate to be processed may be, for example, a metal such as chromium, titanium, tantalum, silicon, or aluminum; a chromium compound such as chromium nitride, chromium oxide, or chromium oxynitride; a tantalum compound such as tantalum oxide, tantalum oxynitride, tantalum oxide boride, or tantalum oxynitride; titanium nitride, silicon nitride, silicon oxide, or silicon oxynitride; or the like, which may be used alone or in combination of two or more thereof.

[0118] The hard mask layer is patterned in a process described later (see FIG. 2(f)) and is used as a mask when etching the substrate to be processed. Therefore, it is preferable to select a material for the hard mask layer in consideration of the etching selectivity and the like depending on the type of substrate to be processed. For example, when the substrate to be processed is a quartz glass substrate, a metal chromium film or the like can be suitably selected as the hard mask layer.

[0119] The thickness of the hard mask layer is appropriately set in consideration of the etching selectivity depending on the type of substrate to be processed, the aspect ratio of the concave-convex pattern on the substrate to be processed, etc. For example, when producing an imprint mold, the thickness of the hard mask layer can be set to about 1.0 nm to 5.0 nm.

[0120] The method for forming the hard mask layer is not particularly limited, and examples thereof include known film formation methods such as sputtering, PVD (Physical Vapor Deposition), and CVD (Chemical Vapor Deposition).

[0121] The core pattern can be formed by a conventionally known method, for example, by an imprint method using a known organic resist material (e.g., ultraviolet-curable resin, thermosetting resin, etc.), or by applying an electron beam-sensitive or photosensitive organic resist material and then using electron beam lithography, photolithography, etc.

[0122] The curable resin composition for a silicon-containing resist was described in detail above in "A. Curable resin composition for a silicon-containing resist," so further description here is omitted.

[0123] Examples of methods for applying the curable resin composition for silicon-containing resists onto the concaves and convexes of the concave-convex structure include a method in which droplets of an inversion layer-forming material are discretely supplied onto the concaves and convexes from an inkjet nozzle using an inkjet method, a method in which an inversion layer-forming material on a plate is supplied onto the concaves and convexes using a squeegee using a plate-based printing method such as stencil printing (screen printing), a die coating method, a spin coating method, etc. Among these, the inkjet method is preferred in the present disclosure.

[0124] (2) Flattening process The pattern formation method according to the present disclosure preferably includes a planarization step (FIG. 1(c)) after the above-mentioned (1) coating step. The planarization step is a step in which the silicon-containing resist curable composition 14 coated on the concave-convex structure 10 is cured while a flat mold 5 is pressed against the cured composition 14 from above to obtain a cured layer 4.

[0125] By performing the planarization step in this manner, the curable composition for a silicon-containing resist can be wetted and spread over the irregularities, and the upper surface of the cured layer can be smoothed. As described above, since the resin composition of the present disclosure does not substantially contain a solvent, a cured layer with good flatness can be obtained.

[0126] When the resin composition is cured by light irradiation, the light irradiation may be performed from the flat mold side, or, for example, when the substrate to be processed is transparent and the flat mold is opaque, the light may be irradiated from the substrate to be processed. The light to be irradiated is appropriately selected depending on the wavelength sensitivity of the resin composition. For example, ultraviolet light having a wavelength in the range of 150 nm to 400 nm, X-rays, electron beams, etc. may be used, with ultraviolet light being particularly preferred. Examples of light sources that emit ultraviolet light include high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, deep-UV lamps, carbon arc lamps, chemical lamps, metal halide lamps, xenon lamps, KrF excimer lasers, ArF excimer lasers, and F2 excimer lasers, with ultra-high-pressure mercury lamps being particularly preferred.

[0127] When the resin composition is cured by heating, the temperature is preferably set to 40°C or higher and 120°C or lower.

[0128] The flat mold pressed against (contacted with) the curable resin composition for silicon-containing resists is not particularly limited. However, if active energy rays are irradiated through the flat mold during curing of the resin composition, a transparent substrate such as quartz glass is preferably used. Furthermore, if the substrate to be processed is transparent and the resin composition can be cured by irradiating active energy rays from the side opposite the textured surface of the substrate, an opaque substrate (with low transmittance of active energy rays (e.g., less than 85%)) may be used as the flat mold. Furthermore, the surface roughness (Ra) of the surface of the flat mold pressed against (contacted with) the inversion layer-forming material is preferably 0.1 nm to 1.0 nm, more preferably 0.2 nm to 0.5 nm. A flat mold having a surface with a surface roughness (Ra) of less than 0.1 nm is inherently difficult to fabricate. On the other hand, if the surface roughness (Ra) exceeds 1.0 nm, the dimensional accuracy of the pattern formed on the substrate may be reduced.

[0129] Furthermore, the flat mold is preferably gas permeable, because gas permeability allows the flat mold to absorb and transmit gas even if bubbles (e.g., helium gas) remain in the recesses of the concave-convex structure, thereby preventing defects from occurring in the cured layer of the resin composition. Examples of such gas-permeable flat molds include those using TiO2-SiO2 glass (e.g., International Publication No. 2011 / 096368). TiO2-SiO2 glass also has the advantage of being equivalent to or superior to synthetic quartz glass in terms of optical transparency and thermal stability.

[0130] After the planarization step is completed, it is preferable that the flat mold can be easily peeled off from the cured layer. On the other hand, from the viewpoint of obtaining the desired etching characteristics, it is preferable that the curable resin composition of the present disclosure does not contain additives such as a release agent. Therefore, in order to improve the mold releasability, it is preferable to form a release layer on the surface of the flat mold in advance. The release layer is not particularly limited as long as it is made of a material that can reduce the peel force, and examples thereof include fluorine materials, silicone materials, and long-chain alkyl materials. Examples of methods for forming the release layer include spin coating, vapor deposition, and spraying.

[0131] Alternatively, the release agent may be transferred to the flat mold by an imprinting method. Specifically, the techniques described in Japanese Patent Nos. 5714496 and 5889388 can be used. In this technique, a resist containing a release agent (fluorine-containing surfactant) is formed on a substrate, and the resist is pressed against the flat mold. Hydroxyl groups on the surface of the flat mold and hydroxyl groups on the release agent segregated on the resist surface strongly associate with each other through hydrogen bonding interactions, transferring the release agent to the surface of the flat mold.

[0132] (3) Hardened layer etching process 1(a) to 1(c) fills the gaps in the core pattern 3 (protrusions) and is also present on the core pattern 3. The cured layer 4 present on the core pattern 3 is removed by dry etching to expose the tops of the core pattern 3, and the cured layer 4 is etched so as to leave the cured layer 4 (reverse layer) filling the gaps (recesses) of the core pattern 3 (see FIG. 1(d)).

[0133] The etching gas for etching the cured layer may be, for example, a fluorine-based gas, etc. Whether the top of the core pattern (protrusion) is exposed can be confirmed visually, by a tactile profilometer, or by an AFM (atomic force microscope).

[0134] (4) Reverse pattern formation process Next, the exposed core pattern 3 (protrusions) is removed by dry etching using the cured layer 4 filling the gaps in the core pattern 3 (protrusions) as a mask. As described above, the resin composition of the present disclosure is a material that has a sufficient etching selectivity with respect to the resist resin that constitutes the core pattern 3, so that by removing the core pattern 3 (protrusions), a reverse pattern 4p can be formed on the hard mask layer 2 (see FIG. 2(e)).

[0135] The etching gas for etching the core pattern 3 can be appropriately selected depending on the type of resist resin that constitutes the core pattern 3, and for example, oxygen can be used. Here, it is preferable to check the film thickness of the reverse pattern 4p using an AFM or the like.

[0136] (5) Hard mask pattern formation process Using the reverse pattern 4p as a mask, the hard mask layer 2 is etched by dry etching using, for example, a chlorine-based etching gas to form a hard mask pattern 2p (see FIG. 2(f)). The resin composition of the present disclosure is a material that has a sufficient etching selectivity with respect to the hard mask layer (particularly the metal chromium layer), and therefore, the hard mask pattern 2p can be formed.

[0137] (6) Etching process of the substrate to be processed Finally, the substrate 1 is subjected to dry etching using the hard mask pattern 2p as a mask, forming a concave-convex pattern on the substrate, thereby obtaining a concave-convex pattern forming body 1p (see FIG. 2(g)). Examples of etching gases include fluorine-based gases. After this, the reverse pattern 4p may be removed by wet etching or the like (FIG. 2(h)).

[0138] The pattern formation method of the present disclosure can form a cured layer 4 with good filling properties and flatness. Therefore, by performing an etching process using the reversal pattern 4p obtained from the reversal layer 4 as a mask, it becomes possible to form a fine pattern (e.g., a dimension of 20 nm or less) with high precision on the substrate to be processed.

[0139] 2. Method for forming a pattern of a multi-level uneven structure (second embodiment) Figures 3 and 4 are schematic process diagrams showing an example of a method for forming a pattern of a multi-stage uneven structure, in which a workpiece substrate 31 (uneven structure 30) having unevenness X2 on its surface is etched using a resin composition disclosed herein to form recesses (Q1, Q2) of different depths.

[0140] (1) Coating process The pattern formation method of the present disclosure includes a coating step of coating a curable resin composition 44 for silicon-containing resists onto a concave-convex structure 30 having a concave-convex structure X2 on its surface so as to cover the concave-convex structure X2 (FIGS. 3(a) and 3(b)). The resin composition of the present disclosure has low viscosity, which prevents the generation of bubbles when applied onto the concave-convex structure, allowing the composition to be applied with good filling properties.

[0141] The concavo-convex structure used in this embodiment may be a substrate 31 to be processed that itself has concavo-convex shapes X2 on its surface, as shown in Figures 3 and 4. The material of the substrate to be processed may be the same as that described in detail in "1. Pattern formation method by reversal process (first embodiment)" above.

[0142] (2) Flattening process The pattern formation method of this embodiment preferably includes a planarization step after the above-mentioned (1) coating step (FIG. 3(c)). The planarization step is a step in which the silicon-containing resist curable composition 44 coated on the concave-convex structure 30 is cured while a flat mold 35 is pressed against the composition from above to obtain a cured layer 34. Examples of flat molds include those similar to those detailed in "1. Pattern formation method by inversion process (first embodiment)" above.

[0143] (3) Resist pattern formation process The hardened layer 34 formed as shown in Figures 3(a) to 3(c) above is applied with good filling properties to the recesses Q1 of the workpiece substrate 31 (protrusion-recess structure 30) having the surface irregularities X2. An organic resist layer is formed on the workpiece substrate 31 as described above, and then patterned to form an organic resist pattern 33 (Figure 3(d)). As shown in Figure 3(d), a hard mask layer 32 may be formed between the hardened layer 34 and the organic resist pattern 33. Materials and formation methods for the organic resist layer (organic resist pattern) and hard mask layer include the same materials and formation methods as those for the core pattern and hard mask layer in the above-mentioned "1. Pattern formation method by reversal process (first embodiment)."

[0144] (4) Etching process of the substrate to be processed Using the organic resist pattern 33 as a mask, the substrate 31 to be processed, which has an uneven surface, is etched (FIGS. 4(e) and 4(f)). The gas used for dry etching can be selected appropriately depending on the elemental composition of the substrate to be processed, and for example, chlorine-based gas, fluorine-based gas, etc. can be used. These gases can be used alone or in an appropriate mixture.

[0145] This allows for the formation of deeper recesses Q2 in addition to the recesses Q1, thereby producing a substrate to be processed having a multi-stage uneven structure.

[0146] C. Imprint mold manufacturing method Next, a method for manufacturing an imprint mold according to the present disclosure will be described with reference to the drawings. The method for manufacturing an imprint mold according to the present disclosure is a method for manufacturing an imprint mold using the above-mentioned "B. Pattern formation method."

[0147] Specifically, the above-mentioned "B. Pattern Formation Method 1. Pattern Formation Method by Inversion Process (First Embodiment)" can be used. Typically, an imprint mold substrate 61 includes a base 61a having a first surface and an opposing second surface, and a convex structure 61b (so-called mesa structure) protruding from the first surface and on which a concave-convex pattern is formed (e.g., FIG. 6(a)). In the inversion process, when a conventional inversion layer material is applied to a core pattern formed on the convex structure, the film thickness of the outer periphery of the inversion layer is greater than the film thickness inside the inversion layer. This creates a problem of uneven film thickness in the inversion layer formed on the core pattern. In imprint molding, the concave-convex pattern may be formed very close to the outer periphery of the convex structure. Therefore, the film thickness of the inversion layer formed on the core pattern is greater than the film thickness inside the inversion layer. This reduces the dimensional accuracy of the concave-convex pattern formed on the convex structure by etching using the inversion layer as a mask.

[0148] According to the present disclosure, for the reasons described above, when a resin composition is applied to a core material pattern 3 formed on a convex structure portion 61b of an imprint mold substrate 61 as shown in Fig. 6(a), the film thickness at the outer periphery does not increase more than the film thickness inside, and a cured layer 4 (inversion layer) with good filling and flatness can be formed. Therefore, an imprint mold 70 in which a fine pattern is formed with high precision can be manufactured (Fig. 6(b)).

[0149] Furthermore, according to the method detailed above in "B. Pattern Forming Method 2. Method for forming a pattern of a multi-stage uneven structure (Second embodiment)", an imprint mold having a multi-stage uneven structure formed thereon can be manufactured.

[0150] D. Semiconductor Device Manufacturing Methods The method for manufacturing a semiconductor device according to the present disclosure is a method for manufacturing a semiconductor device using the above-described pattern formation method. Specifically, a semiconductor device having a highly precise pattern formed thereon can be manufactured by using a substrate to be processed for a semiconductor device and carrying out the reversal process (first embodiment) and the method for forming a pattern with a multi-level uneven structure (second embodiment) detailed in "B. Pattern formation method" above. Such semiconductor devices can be used for integrating, for example, integrated circuits, sensors, optical devices, and the like.

[0151] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Example]

[0152] The present disclosure will be described in more detail below with reference to examples and comparative examples. Example 1 A hard mask layer was formed on a substrate (quartz glass) to be processed. A 30-nm-thick resist layer made of the EB resist material was then formed on the hard mask layer, and a core pattern was obtained by electron beam lithography. Next, the inversion layer-forming composition A was applied to the core pattern and cured while a flat mold was pressed against it from above to obtain a cured layer (FIGS. 1(a)-1(c)). Next, under the conditions described in "6. Other Physical Properties (2) Etching Characteristics" above, etching was performed using fluorine gas for the cured layer etching shown in FIG. 1(d), oxygen gas for the core pattern etching shown in FIG. 2(e), and chlorine gas for the hard mask layer etching shown in FIG. 2(f). A pattern with a width (W in FIG. 2(h)) of 17 nm was formed on the substrate to be processed.

[0153] (Comparative Example 1) The substrate to be processed was etched in the same manner as in Example, except that composition B for forming an inversion layer was used instead of composition A for forming an inversion layer.

[0154] (Comparative Example 2) The substrate to be processed was etched in the same manner as in Example, except that composition C for forming an inversion layer was used instead of composition A for forming an inversion layer.

[0155] Example 2 A substrate to be processed was etched in the same manner as in Example, except that composition D for forming an inversion layer was used instead of composition A for forming an inversion layer.

[0156] (Comparative Example 3) The substrate to be processed was etched in the same manner as in Example, except that composition E for forming an inversion layer was used instead of composition A for forming an inversion layer.

[0157] Table 1 shows the viscosities of the following compositions A to E, and the etching rate ratios of the cured products of compositions A to E to a standard resist using fluorine gas, to a standard resist using oxygen gas, and to a metal chromium layer using chlorine gas. The standard resist used was the standard resist described above in "A. Curable resin composition for silicon-containing resist 6. Other physical properties (1) Wettability." The results of observing the presence or absence of defects in the patterns formed on the workpiece substrate are shown in Table 1. Micrographs of the core pattern, the reverse pattern, and the workpiece substrate after pattern formation (the state of FIG. 2(h)) formed in the example are shown in FIGS. 7(A) to 7(C), respectively.

[0158] (Inversion layer forming composition A) A curable resin composition for a silicon-containing resist was used, which contained a polymerizable compound A having a spherical structure shown below, a reactive crosslinking agent, and a photopolymerization initiator. ·Polymerizable compounds 20% by mass of polymerizable compound A having the following spherical structure

[0159] [ka] The polymerizable compound A was produced by the following method. Reactive crosslinking agent Dimethylsiloxane-containing bifunctional acrylate 79% by mass Photopolymerization initiator Omnirad907 1.0% by mass

[0160] (Method for synthesizing polymerizable compound A) 11.7 g of 3-acryloxypropyltrimethoxysilane was dissolved in 93.9 g of acetone and heated to 50°C. A mixed solution of 13.5 g of ion-exchanged water and 0.07 g of potassium carbonate (K2CO3) was added dropwise to the solution, and the mixture was stirred at 50°C for 5 hours. The resulting reaction solution was washed and extracted with saturated saline and chloroform. The volatile components were removed, yielding polymerizable compound A with a spherical structure.

[0161] (Inversion layer forming composition B) ·Polymerizable compounds 99% by mass of the above polymerizable compound A Photopolymerization initiator Omnirad907 1.0% by mass

[0162] (Inversion layer forming composition C) Dimethylsiloxane-based silicone resin composition 10% by mass 4-methyl-2-pentanol 90% by mass

[0163] (Inversion layer forming composition D) ·Polymerizable compounds 35% by mass of the above polymerizable compound A Reactive crosslinking agent Dimethylsiloxane-containing bifunctional acrylate 64% by mass Photopolymerization initiator Omnirad907 1.0% by mass

[0164] (Inversion layer forming composition E) ·Polymerizable compounds 50% by mass of the above polymerizable compound A Reactive crosslinking agent Dimethylsiloxane-containing bifunctional acrylate 49% by mass Photopolymerization initiator Omnirad907 1.0% by mass

[0165] (EB resist (core pattern) material) ZEP520A (manufactured by Nippon Zeon Co., Ltd.)

[0166] (hard mask layer) Metallic chromium layer (thickness 3nm)

[0167] [Table 1]

[0168] Table 1 and Figure 7 show that the silicon-containing resist curable resin compositions (inversion layer-forming compositions A and D) of the present disclosure have low viscosity and do not contain solvents, and therefore have good filling and planarization properties, and also have good etching properties (Examples 1 and 2). On the other hand, open defects (white defects) were observed in the patterns formed with inversion layer-forming compositions B, C, and E. This is presumably because inversion layer-forming compositions B and E have high viscosity, which results in poor filling of the gaps in the core pattern, causing defects in the cured layer. Furthermore, inversion layer-forming composition C contains a solvent, which presumably results in poor planarization of the cured layer.

[0169] (Reference example) A 50 nm thick EB resist layer was formed on the substrate, and a resist pattern was obtained by electron beam lithography. Without using a reversal process (i.e., without using the resin composition of the present disclosure), the substrate was etched using the resist pattern as a mask to form a 17 nm wide pattern. Micrographs of the resist pattern and the substrate after pattern formation are shown in Figures 8(A) and (B), respectively.

[0170] 7, it was found that a highly accurate fine pattern could be formed by the inversion process using the resin composition of the present disclosure. On the other hand, in the reference example, a fine pattern could not be formed even when the resist layer was thick (FIG. 8).

[0171] 1 … Processed substrate 2...Hard mask layer 3... Core pattern 4...Curable resin composition for silicon-containing resist 5... Flat mold 10 … uneven structure

Claims

[Claim 1] A curable resin composition for a silicon-containing resist, comprising: a polymerizable compound having a siloxane bond in its molecule and at least one polymerizable functional group; and a polymerization initiator, Among the oxygen atoms bonded to silicon atoms contained in the polymerizable compound, the proportion of oxygen atoms bonded to a single silicon atom is 10 mol % or less, The curable resin composition for a silicon-containing resist has a viscosity of 20 cPs or less.

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