Method for manufacturing a laminate, and method for manufacturing a substrate

Abstract

The present invention relates to a method for manufacturing a laminate comprising a substrate and a metal structure, said method including a pattern formation step of forming a pattern on the substrate using a resist composition so as to expose at least part of the surface of the substrate, a metal structure formation step of using the pattern as a template and coating the inside of the template with a metal material to form the metal structure, and a pattern removal step of removing the pattern after the metal structure has been formed.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminate, a method for manufacturing a substrate, and a laminate.

Background Art

[0002] In recent years, with the further miniaturization of large-scale integrated circuits (LSIs), a technique for forming a higher-definition pattern has been demanded. As one of the miniaturization techniques in such demands, a technique for etching a material such as a base material using a metal mask has been studied.

[0003] A metal mask is generally manufactured by a method of forming an opening (through hole) in a metal layer or foil by etching using a photolithography method, a method of forming a plating layer on a patterned resist film and then removing the resist film, or the like.

[0004] For example, Patent Document 1 describes a method for manufacturing a master disk for a nanoimprint process for manufacturing a patterned medium disk using a conductive substrate and a block copolymer, utilizing self-induced organization for forming a pattern of a substantially radial line and / or a substantially concentric ring of one of the block copolymer components, and a technique for electroplating a metal in a region on the substrate that is not protected by the line and / or the ring.

[0005] And, as lithography technology further progresses and pattern miniaturization further advances, since the dimensional accuracy of a fine pattern depends on the accuracy of the metal mask, it is desired to stably manufacture a high-definition metal mask with good dimensional accuracy.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] However, in the technique described in Patent Document 1 above, a metal wire pattern is formed by electroplating a metal within a pattern region formed using a copolymer, making it difficult to obtain a fine pattern with high precision.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a laminate applicable to a metal mask capable of forming fine patterns with high precision, a method for manufacturing the laminate, and a method for manufacturing a substrate using the laminate. [Means for solving the problem]

[0009] As a result of diligent research to solve the above problems, the present inventors have found that a laminate applicable to a metal mask capable of forming fine patterns with high precision can be obtained with the following configuration, a method for manufacturing the laminate, and a method for manufacturing a substrate using the laminate, and have completed the present invention.

[0010] In other words, the present invention is as follows: [1] A method for manufacturing a laminate comprising a substrate and a metal structure, A method for manufacturing a laminate, comprising: a pattern forming step of forming a pattern on the substrate using a resist composition such that at least a portion of the surface of the substrate is exposed; a metal structure forming step of forming the metal structure by applying a metal material into the mold using the pattern as a template; and a pattern removal step of removing the pattern after the formation of the metal structure. [2] The method for manufacturing a laminate according to [1], wherein the substrate includes at least one selected from the group consisting of a semiconductor layer, a ferromagnetic layer, an insulating layer, a metal layer, an SOC (Spin-on-Carbon) layer, an SOG (Spin-on-Glass) layer, and an electrode. [3] The method for manufacturing a laminate according to [1] or [2], wherein the resist composition is a negative-type resist composition. [4] The method for producing a laminate according to [1] or [2], wherein the resist composition is a resin composition for forming a phase separation structure. [5] The method for manufacturing a laminate according to any one of [1] to [4], wherein the metallic material comprises at least one metallic element selected from the group consisting of alkali metals, alkaline earth metals, transition metals of groups 3 to 13 in the periodic table, lanthanides, and actinides. [6] A method for producing a laminate according to any one of [1] to [5], wherein the metal material comprises at least one selected from metal particles, metal salts, and organometallic precursors. [7] The method for manufacturing a laminate according to any one of [1] to [6], wherein the pattern is a hole pattern. [8] A method for manufacturing a laminate according to any one of [1] to [7], wherein in the metal structure forming step, the coating is performed such that the height of the metal material is lower than the height of the pattern. [9] The method for manufacturing a laminate according to any one of [1] to [8], wherein the coating in the metal structure formation step is coating by a spin coating method.

[10] The method for manufacturing a laminate according to any one of items [1] to [9], wherein the metal structure forming step further includes a firing treatment after the coating.

[11] A method for manufacturing a substrate having a structure onto which the pattern used in the manufacturing method described in any one of items (1) to (10) has been transferred, comprising: an etching step of using the metal structure as an etching mask and etching the surface of the substrate exposed from the etching mask; and a step of removing the metal structure.

[12] A laminate comprising a substrate and a metal structure, A metal pattern having a convex portion is formed by the metal structure, A laminate in which the aspect ratio of the convex portion in the metal pattern is 0.1 to 3. 〔13〕 The laminate according to 〔12〕, wherein the width of the convex portion in the metal pattern is 10 nm to 1000 nm and the height is 1 nm to 3000 nm. 〔14〕 The substrate according to 〔12〕 or 〔13〕, wherein the substrate includes at least one selected from the group consisting of a semiconductor layer, a ferromagnetic layer, an insulator layer, a metal layer, a SOC (Spin-on-Carbon) layer, a SOG (Spin-on-Glass) layer, and an electrode. 〔15〕 The laminate according to any one of 〔12〕 to 〔14〕, wherein the metal structure includes at least one metal element selected from the group consisting of an alkali metal, an alkaline earth metal, a transition metal of Groups 3 to 13 in the periodic table, a lanthanoid, and an actinoid.

Advantages of the Invention

[0011] The present invention can provide a laminate applicable to a metal mask capable of forming a fine pattern with high precision, a method for manufacturing the laminate, and a method for manufacturing a substrate using the laminate.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to an embodiment of the present invention. [Figure 2] (a1) to (c1) and (a2) to (c2) of FIG. 2 are schematic views showing an example of a method for manufacturing a laminate according to an embodiment of the present invention. [Figure 3] (a1) to (c1) and (a2) to (c2) of FIG. 3 are schematic views showing an example of a method for manufacturing a substrate according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0013] The embodiments and models for carrying out the present invention will be described in detail below, with the help of figures. In the following description, the symbol "~" indicates that the numbers before and after it are included as the lower and upper limits, respectively. Also, in the following description, the numbers after each component represent the symbols of each component shown in each figure.

[0014] In this specification and in the claims thereof, unless otherwise specified, “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group are replaced by halogen atoms, and examples of such halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0015] "Constituent unit" refers to the monomer unit (monomer unit) that makes up a polymer compound (resin, polymer, copolymer). When it is stated that a group "may have substituents" or "may have substituents," this includes both cases where a hydrogen atom (-H) is substituted with a monovalent group and cases where a methylene group (-CH2-) is substituted with a divalent group.

[0016] "Constituent units derived from styrene" and "constituent units derived from styrene derivatives" refer to constituent units formed by the cleavage of the ethylenic double bond of styrene or a styrene derivative. The term "styrene derivative" refers to a compound in which the α-hydrogen atom of styrene is substituted with other substituents such as alkyl groups and alkyl halides, as well as derivatives thereof. Examples of such derivatives include those in which substituents are bonded to the benzene ring of styrene, even if the α-hydrogen atom is substituted with a substituent. Unless otherwise specified, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded.

[0017] "Exposure" is a concept that includes all forms of radiation exposure. Furthermore, in this disclosure, the amount of each component in a composition means the total amount of multiple substances corresponding to each component present in the composition, unless otherwise specified. In this disclosure, the term "process" includes not only independent processes but also any process that cannot be clearly distinguished from other processes, as long as its intended purpose is achieved. In the notation of groups (atomic groups) in this disclosure, notations that do not specify substitution or unsubstituted include both those with and without substituents. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups.

[0018] Furthermore, the chemical structural formulas in this disclosure may also be described as simplified structural formulas in which hydrogen atoms are omitted. In this specification and in the claims, some structures represented by chemical formulas may contain a chiral carbon, and may have enantioisomers or diastereomers. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture. In this disclosure, "mass%" and "weight%" are synonymous, and "parts by mass" and "parts by weight" are synonymous. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, “resist” means a protective film against physical or chemical processing. Generally, the resist is removed from the workpiece after protection of the workpiece is no longer required.

[0019] A method for manufacturing a laminate according to an embodiment of the present invention is a method for manufacturing a laminate comprising a substrate and a metal structure, comprising: a pattern forming step of forming a pattern on the substrate using a resist composition such that at least a portion of the surface of the substrate is exposed; a metal structure forming step of forming the metal structure by applying a metal material into the mold using the pattern as a template; and a pattern removal step of removing the pattern after the formation of the metal structure.

[0020] The manufacturing method for a laminate according to an embodiment of the present invention uses a pattern formed on a substrate as a mold and forms a metal structure by coating the mold with a metal material. This makes it possible to form fine-sized metal structures on the substrate with high precision compared to forming gold structures by plating. Furthermore, in the manufacturing method according to an embodiment of the present invention, it is easy to adjust the aspect ratio of the metal structure in the laminate.

[0021] Furthermore, the laminate according to the embodiment of the present invention is a laminate comprising a substrate and a metal structure, wherein a metal pattern having protrusions is formed by the metal structure, and the aspect ratio of the protrusions in the metal pattern is 0.1 to 3.

[0022] The laminate according to the embodiment of the present invention has a high etching resistance because the aspect ratio of the protrusions in the metal pattern is 0.1 to 3. By using the metal structure in the laminate as an etching mask, it is possible to form a substrate containing a structure in which a fine pattern has been transferred with high precision. The laminate according to the embodiment of the present invention can be used in a method for manufacturing a substrate.

[0023] Furthermore, a method for manufacturing a substrate according to an embodiment of the present invention is a method for manufacturing a substrate including a structure onto which the pattern used in the above manufacturing method has been transferred, and includes an etching step of etching the surface of the substrate exposed from the etching mask using the metal structure as an etching mask, and a step of removing the metal structure.

[0024] According to the substrate manufacturing method of the embodiment of the present invention, by using the metal structure in the laminate manufactured by the above manufacturing method as an etching mask, a substrate can be formed that includes a structure on which a fine pattern has been transferred with high precision.

[0025] <Laminate> Figure 1 is a schematic cross-sectional view showing an example of a laminate 1 according to an embodiment of the present invention. As shown in Figure 1, the laminate 1 according to an embodiment of the present invention comprises a substrate 3 and a metal structure 2. Figure 1 schematically shows a laminate in which a metal pattern 11 exhibiting an uneven structure is formed on the surface of a substrate 3 by multiple metal structures 2.

[0026] In the laminate 1 according to an embodiment of the present invention, the aspect ratio of the metal structure 2, which is the convex portion 11b, is 0.1 to 3. The convex portion may be singular, but may also be multiple, as shown in Figure 1. The multiple convex portions 11b form a recess 11a. In the laminate shown in Figure 1, a metal pattern 11 (a pattern including multiple pillar-shaped convex portions) exhibiting an uneven structure is formed on the surface of the substrate 3, and the metal pattern 11 comprises recesses 11a and convex portions 11b. In the metal structure 2 shown in Figure 1, the aspect ratio of the protrusion 11b can be calculated from the height h and width w of the protrusion 11b. The spacing between multiple protrusions is preferably in the range of 15 nm to 50 μm. Furthermore, the width w of the protrusion is preferably 10 nm to 1000 nm, and the height h is preferably 1 nm to 3000 nm. While it is difficult to accurately form metal structures of this size on a substrate using conventional techniques such as plating, it has become possible to manufacture them using the laminate manufacturing method of the present invention, which will be described later.

[0027] In Figure 1, a substrate in which a metal pattern 11 is formed by multiple protrusions 11b formed by a metal structure 2 is described, but the number of protrusions may be singular. Furthermore, the shape of the metal pattern is not particularly limited and can be any pattern shape that is commonly formed in semiconductor manufacturing processes, etc. For example, the shape of the metal pattern may be a line pattern, or a pattern that includes multiple pillar-like protrusions. Preferably, the shape of the metal pattern is a pattern that includes multiple pillar-like protrusions.

[0028] In the laminate 1 according to the embodiment of the present invention, there are no particular limitations on the shape of the metal structure 2, but it is preferable that it be a convex portion, as it is preferable to form it using a pattern formed with a resist composition as a template. There are no particular limitations on the shape of the convex portion, and examples include rectangular, columnar (pillar-shaped), linear, lenticular, and rounded shapes, with pillar-shaped convex portions being preferred. The shape of the pillar-like protrusion is not particularly limited, but examples include cylindrical shapes, polygonal prism shapes (such as rectangular prism shapes), etc., and these may be forward-tapered or reverse-tapered shapes. Furthermore, the shape may be such that a cone or hemisphere is placed on top of a cylinder, or a polygonal pyramid is placed on top of a polygonal prism. The substrate 3 and the metal structure 2 in the laminate 1 according to the embodiment of the present invention will be described in detail in <Method for Manufacturing the Laminate>.

[0029] <Method for manufacturing laminates> [Pattern formation process] In a method for manufacturing a laminate according to an embodiment of the present invention, the pattern formation step is a step of forming a pattern on a substrate using a resist composition such that at least a portion of the surface of the substrate is exposed.

[0030] (substrate) There are no particular limitations on the type of substrate used in the embodiments of the present invention, and known substrates can be used. The substrate may include, for example, at least one selected from the group consisting of a semiconductor layer, a ferromagnetic layer, an insulating layer, a metal layer, an SOC (Spin-on-Carbon) layer, an SOG (Spin-on-Glass) layer, and an electrode, with a semiconductor layer being preferred from the viewpoint of requiring fine stacking.

[0031] There are no particular limitations on the materials that make up the substrate. Examples include metals such as silicon (Si), copper (Cu), chromium (Cr), iron (Fe), nickel (Ni), titanium (Ti), gold (Au), aluminum (Al), and gallium (Ga); metal compounds such as TiN and titanium oxide; inorganic materials such as glass, silica, and mica; and organic compounds such as acrylic sheets, polystyrene, cellulose, cellulose acetate, and phenolic resin.

[0032] In layers that the substrate may contain, for example, a semiconductor layer may include at least one selected from GaN, SiO2, SiC, Cr, GaAs, and AlGaAs; a ferromagnetic layer may include iron, cobalt, nickel and its alloys, rare earth metals such as gadolinium, Heusler alloys, manganese alloys such as Cu2MnAl, La1-xSrxMnO3, CrO2, CrBr3, ZrZn2, etc.; an insulating layer may include a rubber-based layer or a glass-based layer; and a metal layer may include a layer containing metals or metal compounds such as TiN, Al, Ti, Si, and stainless steel.

[0033] Furthermore, the size and shape of the substrate used in the embodiments of the present invention are not particularly limited. The substrate does not necessarily need to have a smooth surface, and substrates of various materials and shapes can be appropriately selected. For example, substrates with curved surfaces, flat plates with uneven surfaces, thin flakes, and various other shapes can be used.

[0034] Furthermore, an inorganic and / or organic film may be provided on the surface of the substrate. An example of an inorganic film is an inorganic anti-reflective film (inorganic BARC). An example of an organic film is an organic anti-reflective film (organic BARC).

[0035] (Resist composition) The resist composition used in the embodiments of the present invention may be a positive-type resist composition or a negative-type resist composition, and a negative-type resist composition is preferred from the viewpoint of the chemical resistance of the resist pattern formed. Furthermore, the resist composition of this embodiment may be a resin composition for forming a phase separation structure.

[0036] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition.

[0037] The resist composition used in the embodiments of the present invention may be for an alkaline development process using an alkaline developer during the development process when forming a resist pattern, or it may be for a solvent development process using a developer containing an organic solvent (organic developer) during the development process. In other words, the resist composition used in the embodiments of the present invention may be a "positive-type resist composition for alkaline development processes" that forms a positive-type resist pattern in an alkaline development process, or it may be a "negative-type resist composition for solvent development processes" that forms a negative-type resist pattern in a solvent development process.

[0038] When a resist film is formed using a positive-type or negative-type resist composition, and the resist film is selectively exposed, a difference in solubility in the developer occurs between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive-type, the exposed areas of the resist film are dissolved and removed, forming a positive-type resist pattern. If the resist composition is negative-type, the unexposed areas of the resist film are dissolved and removed, forming a negative-type resist pattern.

[0039] The above-mentioned positive-type resist composition and negative-type resist composition are not particularly limited, and known compositions can be used. For example, resist compositions described in Japanese Patent Publication No. 2021-21773, Japanese Patent Publication No. 2019-159323, Japanese Patent Publication No. 2021-92759, Japanese Patent Publication No. 2021-92659, Japanese Patent Publication No. 2017-37108, Japanese Patent Publication No. 2017-37300, Japanese Patent Publication No. 2020-90628, etc. can be used.

[0040] Furthermore, when a resin composition for forming phase-separated structures is used as the resist composition, self-assembled nanostructures can be formed by the block copolymer contained in the resin composition. By forming self-assembled nanostructures only in specific regions and aligning them in a desired direction to induce phase separation, a phase-separated structure can be formed, and patterns of regular periodic structures such as cylindrical structures and lamellar structures can be created. It is preferable to select a resin composition for forming a phase-separated structure that consists of a block copolymer or random copolymer having at least two polymer chains. These basic structures are formed by covalent bonding between polymers with mutually different chemical properties, such as (block A)-(block B). Specifically, polyethylene, polystyrene, polyisoprene, polyvinylpyridine, polymethyl methacrylate, polydimethylsiloxane, polylactic acid, etc., can be used in combination, but the types are not limited to these.

[0041] By forming self-assembled nanostructures, which are created by microphase separation of block copolymers contained in a resin composition for forming phase-separated structures, only in specific regions and aligning them in a desired direction, a phase-separated structure can be formed, enabling the creation of regular periodic structural patterns such as cylindrical structures and lamellar structures.

[0042] The above-mentioned resin composition for forming the phase separation structure is not particularly limited, and known compositions can be used. For example, resin compositions for forming the phase separation structure described in Japanese Patent Publication No. 2021-17580, Japanese Patent Publication No. 2020-90628, etc., can be used.

[0043] (Pattern formation method using a positive-type resist composition or a negative-type resist composition) There are no particular limitations on the method of forming a pattern using a positive-type resist composition or a negative-type resist composition. One embodiment is a resist pattern formation method carried out as follows. In embodiments of the present invention, there are no particular restrictions on the shape of the pattern formed using the resist composition, and since the pattern is used as a mold for forming a metal structure, it can be selected according to the desired shape of the metal structure. Examples of pattern shapes include hole patterns and line patterns. In embodiments of the present invention, the pattern is preferably a hole pattern.

[0044] First, a positive-type resist composition or a negative-type resist composition is applied to a substrate using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 10 to 120 seconds, preferably 30 to 90 seconds, at a temperature of, for example, 80 to 110°C, to form a resist film. The thickness of the formed resist film can be appropriately set according to the desired metal structure, for example, 5000 nm or less, preferably 3500 nm or less, more preferably 40 nm to 500 nm, and even more preferably 50 nm to 100 nm. Next, the resist film is subjected to selective exposure, such as exposure through a mask (mask pattern) on which a predetermined pattern has been formed, or drawing by direct irradiation with an electron beam without going through a mask pattern, using, for example, an electron beam lithography apparatus, an EUV exposure apparatus, or an exposure apparatus having at least one of the exposure wavelengths of g-line, i-line, h-line, KrF, and ArF. After this, a bake (post-exposure bake (PEB)) treatment is performed for 10 to 120 seconds, preferably 30 to 90 seconds, at a temperature of, for example, 80 to 110°C. Next, the resist film is subjected to a developing process. In the case of an alkaline developing process, an alkaline developer is used, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used.

[0045] After the developing process, a rinsing process is preferably performed. In the case of an alkaline developing process, a water rinse using pure water is preferred, and in the case of a solvent developing process, a rinsing solution containing an organic solvent is preferred. In the case of a solvent development process, after the development or rinsing process, a process may be performed to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After development or rinsing, the film is dried. In some cases, a bake (post-bake) process may be performed after the development process. In this way, a resist pattern can be formed.

[0046] The wavelength used for exposure is not particularly limited, and the exposure can be carried out using ultraviolet rays such as g-rays, h-rays, and i-rays, ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition is highly useful for KrF excimer lasers, ArF excimer lasers, EB, or EUV, even more useful for ArF excimer lasers, EB, or EUV, and particularly useful for EB or EUV. In other words, the resist pattern formation method of this embodiment is particularly useful when the step of exposing the resist film includes an operation of exposing the resist film with EUV (extreme ultraviolet) or EB (electron beam).

[0047] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is first filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film being exposed is preferred. The refractive index of such a solvent is not particularly limited as long as it is within the aforementioned range. Examples of solvents having a refractive index greater than that of air and less than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents.

[0048] Water is preferred as the immersion medium from the viewpoints of cost, safety, environmental issues, and versatility.

[0049] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer solution used in the solvent development process can be any solvent capable of dissolving the resin components (resin components before exposure) contained in the resist composition, and can be appropriately selected from known organic solvents. Specifically, examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0050] Organic developers may contain known additives as needed. Examples of such additives include surfactants. While not particularly limited, surfactants such as ionic or nonionic fluorinated and / or silicone-based surfactants can be used. Nonionic surfactants are preferred, with nonionic fluorinated surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the organic developer.

[0051] The development process can be carried out by known development methods, such as the dipping method, which involves immersing the substrate (a substrate on which a resist film has been formed) in a developer solution for a certain period of time; the paddle method, which involves piling the developer solution onto the substrate surface using surface tension and leaving it still for a certain period of time; the spray method, which involves spraying the developer solution onto the substrate surface; and the dynamic dispensing method, which involves continuously dispensing the developer solution onto a substrate rotating at a constant speed while scanning the developer solution dispensing nozzle at a constant speed.

[0052] As for the organic solvent contained in the rinsing solution used for rinsing after development in the solvent development process, for example, organic solvents that are less likely to dissolve the resist pattern can be appropriately selected and used from among the organic solvents listed as organic solvents used in the organic developer solution. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred.

[0053] The alcohol-based solvent used in the rinsing solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and this monohydric alcohol may be linear, branched, or cyclic. Specifically, examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred.

[0054] These organic solvents may be used individually or in combination of two or more. They may also be mixed with other organic solvents or water. However, considering the developing characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, relative to the total volume of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants are the same as those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total volume of the rinse solution.

[0055] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying the rinsing solution onto a substrate rotating at a constant speed (rotary coating method), immersing the substrate in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the substrate surface (spray method).

[0056] (Pattern formation process using a resin composition for forming phase-separated structures) In the method for manufacturing a laminate according to an embodiment of the present invention, the resist composition may be a resin composition for forming a phase-separated structure. In embodiments of the present invention, a resin composition for forming a phase-separated structure may be used to form a pattern by a self-assembly phenomenon that can create a fine, ordered pattern.

[0057] When a resin composition for forming a phase-separated structure is used as a resist composition, the desired pattern shape and dimensions can be achieved by adjusting various parameters such as the molecular weight of the polymer material.

[0058] One embodiment of a method for forming a pattern using a resin composition for forming a phase-separated structure as a resist material is, for example, the pattern formation method described below.

[0059] First, if necessary, apply a primer to the substrate to form a primer layer. The resin composition for forming the phase separation structure is applied to the primer layer to form a layer containing a block copolymer (BCP layer). Next, the BCP layer is heated and annealed to separate the phases.

[0060] The surface of the substrate may be cleaned before forming the BCP layer on it. Cleaning the substrate surface allows for better application of the phase separation structure forming resin composition or primer to the substrate. Conventional known methods can be used for the cleaning process, such as oxygen plasma treatment, hydrogen plasma treatment, ozone oxidation treatment, acid-alkali treatment, and chemical modification treatment. For example, the substrate is immersed in an acidic solution such as sulfuric acid / hydrogen peroxide aqueous solution, then washed with water and dried. After that, a BCP layer or a primer layer is formed on the surface of the substrate.

[0061] It is preferable to neutralize the substrate before forming the BCP layer. Neutralization treatment refers to a process that modifies the substrate surface to have affinity for any of the polymers constituting the resin composition for forming phase separation structures. By performing neutralization treatment, it is possible to suppress the contact between only a specific polymer phase and the substrate surface due to phase separation. For example, it is preferable to form a primer layer on the substrate surface according to the type of resin composition for forming phase separation structures used before forming the BCP layer. As a result, the phase separation of the BCP layer facilitates the formation of cylindrical or lamellar phase separation structures oriented perpendicular to the substrate surface.

[0062] Specifically, a primer layer is formed on the substrate surface using a primer that has affinity for any of the polymers constituting the resin composition for forming a phase separation structure. Depending on the type of polymer constituting the resin composition for forming the phase-separated structure, conventionally known resin compositions used for thin film formation can be appropriately selected and used as the primer. Examples of such primers include compositions containing a resin having all of the constituent units of each polymer constituting the resin composition for forming a phase separation structure, and compositions containing a resin having all of the constituent units that have high affinity with each of the polymers constituting the resin composition for forming a phase separation structure.

[0063] For example, when using a block copolymer (PS-PMMA block copolymer) having a block of structural units derived from styrene (PS) and a block of structural units derived from methyl methacrylate (PMMA), it is preferable to use a resin composition containing both PS and PMMA, or a compound or composition containing both a part with high affinity for aromatic rings, etc., and a part with high affinity for highly polar functional groups, etc., as a base coat. Examples of resin compositions containing both PS and PMMA as blocks include random copolymers of PS and PMMA, and alternating polymers of PS and PMMA (in which each monomer is copolymerized alternately).

[0064] Furthermore, as a composition containing both a moiety with high affinity for PS and a moiety with high affinity for PMMA, for example, a resin composition obtained by polymerizing at least a monomer having an aromatic ring and a monomer having a highly polar substituent can be cited. Examples of monomers having an aromatic ring include monomers having a group obtained by removing one hydrogen atom from the ring of an aromatic hydrocarbon, such as a phenyl group, biphenyl group, fluorenyl group, naphthyl group, anthryl group, and phenanthryl group, or monomers having a heteroaryl group in which some of the carbon atoms constituting the ring of these groups are substituted with heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of monomers having a highly polar substituent include monomers having a trimethoxysilyl group, trichlorosilyl group, carboxyl group, hydroxyl group, cyano group, and hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms.

[0065] Other examples of compounds containing both a site with high affinity for PS and a site with high affinity for PMMA include compounds containing both an aryl group and a highly polar substituent, such as phenethyltrichlorosilane, and compounds containing both an alkyl group and a highly polar substituent, such as alkylsilane compounds. Other examples of primers include thermopolymerizable resin compositions, photosensitive resin compositions such as positive-type resist compositions and negative-type resist compositions.

[0066] The method for applying the primer onto the substrate to form the primer layer is not particularly limited and can be formed by conventionally known methods. For example, a primer layer can be formed by applying a primer to a substrate using conventionally known methods such as spin coating or using a spinner to form a coating film, and then drying it. The drying method for the coating film can be any method that allows the solvent contained in the primer to volatilize, such as baking. In this case, the baking temperature is preferably 80 to 300°C, more preferably 180 to 270°C, and even more preferably 220 to 250°C. The baking time is preferably 30 to 500 seconds, and more preferably 60 to 400 seconds. The thickness of the primer layer after the coating film has dried is preferably about 10 to 100 nm, and more preferably about 40 to 90 nm.

[0067] Next, a BCP layer is formed on the primer layer using a resin composition for forming a phase-separated structure. The method for forming the BCP layer on the primer layer is not particularly limited, and examples include applying a phase-separation structure-forming resin composition onto the primer layer by conventionally known methods such as using spin coating or a spinner to form a coating film and then drying it.

[0068] As for drying the coating film of the resin composition for forming a phase separation structure, it is sufficient to volatilize the organic solvent components contained in the resin composition for forming a phase separation structure, and examples of such methods include shaking dry or baking.

[0069] The thickness of the BCP layer should be sufficient for phase separation to occur. Considering the type of substrate, the structural period size of the formed phase separation structure, or the uniformity of the nanostructure, a thickness of 10 to 100 nm is preferred, and 20 to 80 nm is more preferred. For example, when the substrate is a Si substrate or an SiO2 substrate, the thickness of the BCP layer is preferably 20 to 100 nm, and more preferably 30 to 80 nm. When the substrate is a Cu substrate, the thickness of the BCP layer should be sufficient for phase separation to occur. Considering the type of underlying film / substrate, the structural period size of the formed phase separation structure, or the uniformity of the nanostructure, a thickness of 10 to 100 nm is preferred, and 20 to 80 nm is more preferred.

[0070] Next, the BCP layer formed on the substrate is phase-separated. By heating a substrate on which a BCP layer has been formed and performing an annealing treatment, a phase-separated structure is formed in which at least a portion of the substrate surface is exposed by selective removal of the block copolymer.

[0071] The temperature conditions for the annealing process are preferably 210°C or higher, more preferably 220°C or higher, even more preferably 230°C or higher, and particularly preferably 240°C or higher. The upper limit of the temperature conditions for the annealing process is not particularly limited, but it is preferably below the thermal decomposition temperature of the block copolymer. For example, the temperature conditions for the annealing process are preferably 400°C or lower, more preferably 350°C or lower, and even more preferably 300°C or lower. The temperature range for the annealing process is preferably 210 to 400°C, more preferably 220 to 350°C, even more preferably 230 to 300°C, and particularly preferably 240 to 300°C.

[0072] Furthermore, the heating time in the annealing process is preferably 1 minute or more, more preferably 5 minutes or more, even more preferably 10 minutes or more, and particularly preferably 15 minutes or more. There is no particular upper limit to the heating time, but from the viewpoint of process time management, it is preferably 240 minutes or less, and more preferably 180 minutes or less. The range of heating time in the annealing process is, for example, preferably 1 to 240 minutes, preferably 5 to 240 minutes, more preferably 10 to 240 minutes, even more preferably 15 to 240 minutes, and particularly preferably 15 to 180 minutes. Furthermore, the annealing process is preferably carried out in a low-reactivity gas such as nitrogen.

[0073] [Metal structure formation process] In the method for manufacturing a laminate according to an embodiment of the present invention, the metal structure formation step is a step of forming the metal structure by using the pattern as a mold and applying a metal material into the mold. By forming metal structures by coating rather than plating, fine metal structures can be formed with high precision within a mold. Furthermore, it is possible to form metal structures with aspect ratios of 0.1 to 3, which are difficult to form with conventional techniques. In conventional techniques for forming metal structures by plating, stress is applied to the resist pattern due to the plating, so it was necessary to use a soft resist pattern that could withstand the stress caused by the plating. However, fine patterns cannot be formed with soft resist patterns because the pattern tends to collapse, making it difficult to achieve fine pattern formation. However, when forming metal structures by coating, formation is possible regardless of the hardness of the resist material, so fine patterns can be formed with high precision.

[0074] (metal structure) In the method for manufacturing a laminate according to the embodiments of the present invention, there are no particular limitations on the shape of the metal structure as long as it can be formed using the above pattern as a mold, and as described above, it can be any shape. In embodiments of the present invention, the shape of the metal structure is preferably a convex portion. The shape of the convex portion is not particularly limited, and examples include rectangular, columnar (pillar-shaped), linear, lenticular, and rounded shapes, with a pillar-shaped convex portion being preferred. The shape of the pillar-like protrusion is not particularly limited, but examples include a line shape, a cylindrical shape, a polygonal prism shape (such as a rectangular prism shape), etc., and these may be forward-tapered or reverse-tapered shapes. Furthermore, the shape may be such that a cone or hemisphere is placed on top of a cylinder, or a polygonal pyramid is placed on top of a polygonal prism. Furthermore, a metal pattern, commonly formed in semiconductor manufacturing processes, may be created by the multiple protrusions. The metal pattern formed by the multiple protrusions may be a line pattern or a pillar pattern.

[0075] The aspect ratio of the protrusions in the metal pattern 11 is preferably 0.1 to 3, more preferably 0.5 to 2, and even more preferably 0.7 to 1. The aspect ratio of the protrusion can be calculated using the height h / width w of the protrusion 11b in the metal pattern 11, as shown in Figure 1. The width w of the protrusion is preferably 10 nm or more. The upper limit is preferably 1000 nm or less, and more preferably 100 nm or less. The height h of the protrusion is preferably 1 nm or more, more preferably 2 nm or more, and even more preferably 3 nm or more. The upper limit is preferably 3000 nm or less, more preferably 300 nm or less, and even more preferably 30 nm or less. Furthermore, it is preferable that the width w of the protrusion is 10 nm to 1000 nm and the height h is 1 nm to 3000 nm.

[0076] Metal structures can be formed by using a pattern formed from a resist material as a template, and then applying a metal material into the template. The formation of metal structures can be confirmed, for example, using the Rapid Thermal Annealing process under firing conditions of 250°C and 450°C in a nitrogen atmosphere.

[0077] Furthermore, the metal structure can be used as an etching mask in the substrate manufacturing method according to the embodiment of the present invention described later.

[0078] (metallic material) In the method for manufacturing a laminate according to embodiments of the present invention, the metal material preferably contains at least one metal element selected from the group consisting of alkali metals, alkaline earth metals, transition metals of groups 3 to 13 of the periodic table, lanthanides, and actinides. Furthermore, in the laminate according to embodiments of the present invention, the metal structure preferably contains at least one metal element selected from the group consisting of alkali metals, alkaline earth metals, transition metals of groups 3 to 13 of the periodic table, lanthanides, and actinides. In particular, it is preferable to include copper, silver, gold, nickel, palladium, platinum, cobalt, rhodium, iridium, iron, ruthenium, osnium, rhenium, chromium, molybdenum, tungsten, vanadium, niobium, tantalum, titanium, zirconium, hafnium, magnesium, silicon, germanium, tin, lead, aluminum, zinc, cadmium, gallium, indium, thallium, antimony, bismuth, ytterbium, or alloys thereof, and it is preferable to use zirconium, copper, silver, iron, nickel, or ruthenium, and it is especially preferable to use zirconium.

[0079] Furthermore, when a metallic material is said to contain metallic elements, it does not mean that it contains metallic elements as impurities, but rather that it intentionally contains metallic elements. There are no particular restrictions on the content of metallic elements in metallic materials, but for example, it is between 1% by mass and 99% by mass.

[0080] In the method for manufacturing a laminate according to embodiments of the present invention, examples of the metallic material include metal particles, metal salts, and organometallic precursors. Preferably, the metallic material includes at least one selected from metal particles, metal salts, and organometallic precursors.

[0081] Examples of metal particles include not only particles of the metal itself, but also metal oxide particles, metal nitride particles, and metal sulfide particles.

[0082] The metal oxide particles are preferably selected from the group consisting of zirconium oxide, hafnium oxide, aluminum oxide, tungsten, titanium oxide, copper oxide, cuprous oxide, tin oxide, cerium oxide, indium tin oxide, zinc oxide, yttrium oxide, lanthanum oxide, and indium oxide, and more preferably selected from the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, aluminum oxide nanoparticles, tungsten nanoparticles, and titanium oxide nanoparticles.

[0083] Examples of metal nitride particles include at least one metal nitride particle selected from the group consisting of titanium nitride, titanium oxynitride, silicon nitride, silicon oxynitride, tantalum nitride, tantalum oxynitride, tungsten nitride, tungsten oxynitride, cerium nitride, cerium oxynitride, germanium nitride, germanium oxynitride, hafnium nitride, hafnium oxynitride, cesium nitride, cesium oxynitride, gallium nitride, and gallium oxynitride.

[0084] Preferably, the metal sulfide particles are selected from the group consisting of, for example, zirconium sulfide, hafnium sulfide, aluminum sulfide, tungsten sulfide, titanium sulfide, copper sulfide, tin sulfide, cerium sulfide, indium tin sulfide, zinc sulfide, yttrium sulfide, lanthanum sulfide, and indium sulfide.

[0085] The metal particles may be dispersed in a solvent or the like for use in liquid-phase coating. In this case, they are preferably metal nanoparticles, with an average particle size of 1 to 100 nm, and more preferably 3 to 10 nm.

[0086] Organic solvents are preferred as solvents for dispersing metal particles, such as hydroxyalkylene oxyalkyl (HO-alkylene-O-alkyl), hydroxyalkylene carbonyl oxyalkyl (HO-alkylene-CO2-alkyl), alkyloxyalkylene oxyalkyl (alkyl-O-alkylene-O-alkyl), alkyloxyalkylene carbonyl oxyalkyl (alkyl-O-alkylene-CO2-alkyl), alkyloxyalkylene oxycarbonylalkyl (alkyl-O-alkylene-O-CO-alkyl), cyclic alkylene oxycarbonyl oxy (cyclic (-alkylene-O-CO2-) (also known as lactone), alkyl esters of alkyl carboxylic acids or formic acid (alkyl-O-CO-alkyl (or -H)), alkyl carbonate ( Examples include alkyl-O-CO2-alkyl, cyclic alkylene carbonate (cyclic (-alkylene-OCO2-), alkyl ether (alkyl-O-alkyl), ketone (alkyl-CO-alkyl and cyclic (-alkylene-CO-), alkylamide (alkyl-CONH-alkyl); dialkylamide (alkyl-CO(alkyl)-alkyl), cyclic alkyleneamide (cyclic (-alkylene-NH-)) (also known as lactam), cyclic N-alkylalkyleneamide (cyclic (-alkylene-N(alkyl)-)) (also known as N-alkyl lactam), organic aromatic solvents and mixtures thereof, and are more preferably selected from the group consisting of propylene glycol methyl ether acetate, propylene glycol methyl ether, cyclohexanone, ethyl lactate, and mixtures thereof.

[0087] A metal particle dispersion, obtained by dispersing metal particles in a solvent or the like, may further contain any additives, which can be selected from the group consisting of, for example, catalysts, crosslinking agents, photoacid generators, organic polymers, inorganic polymers, surfactants, wetting agents, defoaming agents, thixotropes, and combinations thereof.

[0088] The solid content in the metal particle dispersion is preferably 1 to 60% by mass, and more preferably 5 to 55% by mass. The content of metal particles in the metal particle dispersion is preferably 1 to 60% by mass, and more preferably 5 to 55% by mass.

[0089] When using metal particles in vapor-phase coating, the metal particles themselves can be used as the target.

[0090] Examples of metal salts include inorganic metal salts and organometallic salts. Inorganic metal salts are formed from metal ions and inorganic counterions. The metal ions can be selected from the group consisting of ions of the above-mentioned metal elements, and it is preferable to select from zirconium, aluminum, titanium, hafnium, tungsten, molybdenum, tin, indium, gallium, zinc, and combinations thereof. The inorganic counterion can be selected from the group consisting of, for example, nitrate ions, sulfate ions, sulfonate ions, and combinations thereof.

[0091] Organometallic salts are formed from metal ions and organic counterions. The metal ions can be selected from the group consisting of ions of the above-mentioned metal elements, and it is preferable to select from zirconium, aluminum, titanium, hafnium, tungsten, molybdenum, tin, indium, gallium, zinc, and combinations thereof. As organic counterions, for example, they can be selected from the group consisting of acetate ions, fluorinated alkyl acetate ions, fluorinated alkyl acrylate ions, methacrylate ions, and combinations thereof.

[0092] The metal salt is preferably selected from zirconyl nitrate, aluminum nitrate, zirconyl methacrylate, aluminum sulfate, titanium oxysulfate, aluminum trifluoroacetate, aluminum trifluoromethylsulfonate, and combinations thereof, with zirconyl nitrate or aluminum trifluoromethylsulfonate being preferred, and zirconyl nitrate being even more preferred.

[0093] Metal salts can be prepared as metal salt solutions, or as metal salt solutions containing a solvent. Preferably, the solvent in the metal salt solution is selected from the group consisting of water, alcohol, ether, ester, ether ester, alkyl carboxylic acid, ketone, ketone ester, lactone, diketone, and combinations thereof.

[0094] The metal salt solution may further contain any additives, which are selected from the group consisting of, for example, catalysts, crosslinking agents, photoacid generators, organic polymers, inorganic polymers, surfactants, wetting agents, defoaming agents, thixotropes, and combinations thereof.

[0095] The total solids content in the metal salt solution is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass. The content of the metal element in the metal salt solution is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass.

[0096] In embodiments of the present invention, the organometallic precursor can undergo hydrolysis and condensation to form an organometallic oxide, thereby forming a metal structure. Various organometallic precursors can be used to form a fine metal structure by coating. Examples of metal elements in organometallic precursors include at least one metal selected from titanium, vanadium, zirconium, tantalum, lead, antimony, thallium, indium, ytterbium, gallium, hafnium, niobium, molybdenum, ruthenium, rhodium, rhenium, osnium, iridium, aluminum, magnesium, germanium, tin, iron, cobalt, nickel, copper, zinc, gold, silver, chromium, cadmium, tungsten, and platinum, with zirconium being preferred.

[0097] More specifically, examples of organometallic precursors include ammonium zirconium carbonate, zirconium(IV) oxide 2-ethylhexanoate, zirconium(IV) acetylacetonate, and zirconium acetate.

[0098] The organometallic precursor is preferably a colloidally stable nanoparticle, with an average particle size of 5 to 50 nm, more preferably 5 to 25 nm, and even more preferably 5 to 20 nm. Organometallic oxides obtained by, for example, carboxylating nanoparticles of organometallic precursors are also nanoparticles and exhibit colloidal stability. One or more organometallic precursors can be used.

[0099] Organometallic compounds are compounds that have a bond between a metal element and a carbon element. Organometallic oxides are oxides of organometallic compounds.

[0100] Examples of organometallic oxides include metal oxide dicarboxylates, metal alkoxide compounds, metal chelate compounds, and metal acylate compounds. Examples of metal oxide dicarboxylates include those represented by the following formula (Equation 1).

[0101] [RC(=O)O - ]2[M(O)] 2+ (Formula 1)

[0102] (R represents a hydrocarbon group with 2 to 5 carbon atoms, [RC(=O)O - ] represents a carboxylate ligand. M represents at least one metal selected from titanium, vanadium, zirconium, tantalum, lead, antimony, thallium, indium, ytterbium, gallium, hafnium, niobium, molybdenum, ruthenium, rhodium, rhenium, osnium, iridium, aluminum, magnesium, germanium, tin, iron, cobalt, nickel, copper, zinc, gold, silver, chromium, cadmium, tungsten, and platinum.

[0103] R represents a hydrocarbon group having 2 to 5 carbon atoms, which may have substituents, be saturated or unsaturated, and be branched or unbranched.

[0104] Examples of saturated branched or unbranched carboxylate ligands with R having 2 to 5 carbon atoms include propanoates or isopropanoates; butanoates, isobutanoates, sec-butanoates, or tert-butanoates; pentanoates or any pentanoate isomers; hexanoates or any hexanoate isomers. Unsaturated branched or unbranched carboxylate ligands with R having 2 to 5 carbon atoms can also be used, for example, acrylates, methacrylates, butenoates, pentenoates, hexenoates, or their isomers.

[0105] The carboxylate may be substituted with a hydroxide, halide, chalcogen, or analogue, either substituted within the chain or bonded to the chain.

[0106] M is preferably zirconium, titanium, or tungsten, with zirconium being more preferred.

[0107] The metal oxide dicarboxylate is preferably zirconium oxide dipropionate or titanium oxide dipropionate, and more preferably zirconium oxide dipropionate.

[0108] Organometallic oxides may also be in the form of solutions containing a solvent. Examples of solvents include ethers, esters, ether esters, ketones, and ketone esters. More specifically, examples include ethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, acetate esters, hydroxyacetate esters, lactate esters, ethylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ether acetates, alkoxyacetate esters, (non)cyclic ketones, acetacetate esters, pyrubate esters, and propionate esters. The solvents mentioned above can be used individually or as a mixture of two or more. Furthermore, at least one high-boiling point solvent, such as benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonylacetone, caproic acid, capric acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, and phenyl cellosolve acetate, may be added to the above solvent.

[0109] There are no particular restrictions on the method for producing metal oxide dicarboxylates, and general methods can be used. For example, a metal oxide dicarboxylate composition can be obtained by adding an organometallic precursor solution, in which an organometallic precursor corresponding to the metal oxide dicarboxylate is dissolved in a suitable solvent, and a desired carboxylate in the form of an acid or salt.

[0110] The organometallic precursor solution and the metal oxide dicarboxylate composition may further contain an organic or inorganic polymer that can be crosslinked by heat treatment. Upon heat treatment, the metal oxide dicarboxylate is thermally decomposed, while the polymer undergoes thermal crosslinking, forming a metal structure with a high metal oxide content.

[0111] The organometallic precursor solution and the metal oxide dicarboxylate composition may further contain organic or silicon-based polymers, such as polyacrylics, polymethacrylics, and condensation polymers, such as polyesters, novolac resins, siloxane resins, or organosilsesquioxanes.

[0112] These polymers can be used individually or in combination with each other. These polymers are generally crosslinkable polymers containing any of a range of identical or different crosslinkable substituents, such as epoxides, hydroxyls, thiols, amines, amides, imides, esters, ethers, ureas, carboxylic acids, anhydrides, and analogues. Other examples of crosslinking groups include glycidyl ether groups, glycidyl ester groups, glycidyl amino groups, methoxymethyl groups, ethoxymethyl groups, benzyloxymethyl groups, dimethylaminomethyl groups, diethylaminomethyl groups, dimethylolaminomethyl groups, diethylolaminomethyl groups, morpholinomethyl groups, acetoxymethyl groups, benzyloxymethyl groups, formyl groups, acetyl groups, vinyl groups, and isopropenyl groups.

[0113] The organometallic precursor solution and the metal oxide dicarboxylate composition may further contain optional additives, which are selected from the group consisting of, for example, catalysts, crosslinking agents, photoacid generators, surfactants, wetting agents, defoaming agents, thixotropes, and combinations thereof.

[0114] The solid content in the organometallic precursor solution is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass. Furthermore, the content of metal elements in the organometallic precursor solution is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass.

[0115] The solid content in the metal oxide carboxylate solution is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass. The metal element content in the metal oxide carboxylate solution is preferably in the range of about 5% by mass to about 50% by mass.

[0116] (Application) In the metal structure formation process according to the embodiment of the present invention, the above pattern is used as a mold, and a metal material is applied to the mold to form the metal structure. In conventional techniques for plating metal onto a substrate using resist patterns, the resist pattern is subjected to stress during plating, requiring the use of a soft resist pattern that can withstand this stress. However, fine patterns cannot be formed with soft resist patterns because they are prone to deformation. Therefore, it has been difficult to plate metal onto a substrate using fine resist patterns, and it has been impossible to manufacture fine patterns using metal structures on a substrate. On the other hand, we have found that by forming metal structures using coating of metal materials, it is possible to uniformly coat fine patterns with metal materials.

[0117] There are no particular restrictions on the coating method, and examples include gas-phase coating and liquid-phase coating, with liquid-phase coating being preferred. The coating can be repeated until the desired film thickness is obtained.

[0118] For liquid-phase coating, techniques well known to those skilled in the art can be used. For example, coating can be applied to the substrate using dip coating, spin coating, curtain coating, slot coating, spray coating, and similar methods.

[0119] In the metal structure formation process according to the embodiment of the present invention, coating by spin coating is preferred from the viewpoint of making the coating film thickness uniform and making it easier to control the coating film thickness. In the spin coating method, the coating film thickness can be controlled by adjusting the rotation speed, the solid content concentration of the metal material, viscosity, and other factors. According to the spin coating method, even with fine patterns such as those with narrow recesses 11a or high heights in the metal pattern 11 shown in Figure 1, it is possible to easily achieve a uniform coating thickness and form a metal structure that is in contact with the substrate surface.

[0120] In the spin coating method, the solid content concentration of the metal material is, for example, 1 to 65% by mass, preferably 2 to 65% by mass, and more preferably 3 to 60% by mass. In the spin coating method, the viscosity of the metal material is preferably, for example, 3000 to 5000 cp, and more preferably 3500 to 4500 cp.

[0121] The film thickness of the coated metal material is preferably 5 nm to 1000 nm, more preferably 10 nm to 520 nm, and even more preferably 50 nm to 400 nm. The film thickness of the coated metal material is preferably smaller (thinner) than the film thickness of the pattern. That is, it is preferable to coat the material so that the height of the metal material is lower than the height of the pattern. By making the film thickness of the metal material thinner than the film thickness of the pattern, it is possible to prevent the pattern from being covered with the metal material, making it easier to remove the pattern and reducing the amount of pattern residue left after removal.

[0122] For vapor-phase coating, techniques well known to those skilled in the art can be used, such as coating by physical vapor deposition (PVD). Examples of PVD methods include vacuum deposition, molecular beam epitaxy, sputtering, ion plating, and laser deposition (ablation), and known methods and conditions can be used.

[0123] For example, sputtering methods include, for instance, diode sputtering, triode sputtering, tetraode sputtering, magnetron sputtering, high-frequency sputtering, reactive sputtering, bias sputtering, asymmetric sputtering, and getter sputtering. Among metal materials, metals and metal particles (metal oxides, metal nitrides, metal sulfides, etc.) are preferred as sputtering targets. For sputtering conditions, known conditions can be adopted depending on the type of target. According to the sputtering method, even with fine patterns such as those where the width of the recesses 11a of the metal pattern 11 in Figure 1 is narrow or the height of the metal pattern 11 is high, a metal structure can be formed so as to be in contact with the substrate surface.

[0124] (Firing process) In the metal structure forming process according to the embodiment of the present invention, a firing process may be included after the application of the metal material. The firing temperature in the firing process is preferably 180 to 480°C, more preferably 220 to 460°C, and even more preferably 250 to 450°C. The firing time in the firing process is preferably 1 to 15 minutes, and more preferably 5 to 15 minutes.

[0125] When an organometallic precursor is used as the metallic material, the metal oxide dicarboxylate decomposes during heat treatment, resulting in a highly crosslinked metallic structure. It is believed that the dicarboxylate decomposes at the hardening temperature and then evaporates either as a carboxylate or as a volatile composition product, forming a highly crosslinked metallic structure.

[0126] The metal material according to the embodiment of the present invention may further contain an organic or inorganic polymer that can be crosslinked during heat treatment. When an organometallic precursor solution containing an organic or inorganic polymer is used as the metal material, the metal oxide dicarboxylate is thermally decomposed by the calcination treatment, while the polymer undergoes thermal crosslinking, thereby forming a metal structure with a high metal oxide content.

[0127] [Pattern removal process] A method for manufacturing a laminate according to an embodiment of the present invention includes a pattern removal step to remove the pattern after the formation of the metal structure. Figures 2(a1)-(c1) and (a2)-(c2) are schematic diagrams showing an example of a method for manufacturing a laminate according to an embodiment of the present invention. Figures 2(a2)-(c2) are cross-sectional views AA of Figures 2(a1)-(c1). Figures 2(a1) and (a2) show the state in which pattern 5 has been formed on substrate 3 by the pattern formation process, (b1) and (b2) show the state in which metal structure 2 has been formed by the metal structure formation process, and (c1) and (c2) show the state in which pattern 5 has been removed by the pattern removal process. As shown in Figures 2(b1)-(c1) and (b2)-(c2), after the metal structure 2 is formed on the substrate 3 by the metal structure formation process, the pattern 5 is removed in the pattern removal process. The method for removing (peeling off) pattern 5 is not particularly limited and includes methods such as dry etching and wet etching.

[0128] Wet etching using a stripping solution has advantages such as easy removal and less residue of pattern 5 remaining on the substrate after removal.

[0129] The stripping solution is not particularly limited as long as it can remove pattern 5, and can be appropriately selected from stripping solutions conventionally used for stripping photosensitive resin compositions. Examples of stripping solutions include the developer solutions mentioned above; organic solvent-based stripping solutions and amines such as monoethanolamine, diethanolamine, and triethanolamine; quaternary ammonium hydroxides such as tetramethylammonium hydroxide; basic alkali metal compounds such as sodium hydroxide, potassium hydroxide, and sodium carbonate; and basic stripping solutions containing bases such as ammonia. The solvent contained in the basic stripping solution can be appropriately selected from water, organic solvents, and aqueous solutions of organic solvents.

[0130] The method for removing pattern 5 with the stripping solution is not particularly limited. Examples of methods for removing pattern 5 with the stripping solution include the liquid application method, the dipping method, the paddle method, and the spray method. In the pattern removal process, after removing the pattern using a stripping solution, a rinsing treatment may be performed. After peeling off pattern 5 or rinsing, drying may be performed. In some cases, baking (post-baking) may be performed after the peeling process described above.

[0131] Dry etching can be used for removal by methods such as plasma (oxygen, nitrogen, argon, trifluoromethane, etc.) or corona discharge. There are no particular limitations on the gas used for etching, but examples include the noble gases, carbon-hydrogen gases, and other gases listed in Table 1. Dry etching is an anisotropic etching process, which offers advantages in terms of pattern dimension control and other aspects. In this way, pattern 5 can be eliminated.

[0132] <Manufacturing method for substrates> A method for manufacturing a substrate according to an embodiment of the present invention is a method for manufacturing a substrate having a structure onto which the pattern used in the above manufacturing method has been transferred, comprising: an etching step of etching the surface of the substrate exposed from the etching mask using the metal structure as an etching mask; and a step of removing the metal structure. Figures (a1) to (c1) and (a2) to (c2) in Figure 3 are schematic diagrams showing an example of a substrate manufacturing method according to the present invention. Figures (a2) to (c2) in Figure 3 are cross-sectional views AA of Figures (a1) to (c1) in Figure 3. Figures 3(a1) and (a2) show a laminate in which a metal pattern 11 is formed by a metal structure 2 on a substrate 3, (b1) and (b2) show the state in which the surface of the substrate 3 has been etched by the etching process, and (c1) and (c2) show the state in which the metal structure 2 has been removed by the metal structure removal process.

[0133] (Etching process) The etching process involves using a metal structure as an etching mask and etching the surface of the substrate 3 that is exposed from behind the etching mask. The areas in the laminate where no metal structure is formed are the substrate surfaces exposed from the etching mask. As shown in Figures 3(a1)-(b1) and (a2)-(b2), the metal structure 2 is used as an etching mask, and the surface of the substrate 3 exposed from the etching mask can be etched by the etching process. In the etching process according to the embodiment of the present invention, there are no particular limitations on the etching method, and it can be appropriately selected from known etching methods depending on the material of the substrate.

[0134] Etching methods include, for example, etching using lasers, ion beams, electron beams, neutral particle beams, etching gases, etc. Positive or negative ions present in a plasma, when accelerated by an electric field, undergo charge exchange through collisions with atoms, molecules, electrons, and walls, becoming neutralized. At this time, kinetic energy is conserved, and a directional neutral particle beam is generated, which can then be used for etching.

[0135] The etching gas can be appropriately selected from known gases depending on the material and thickness of the substrate. For example, the gases listed in Table 1 below are examples, and if the substrate is a Si substrate, it is preferable to use fluorocarbon (CF-based) gases such as PFC gas, HFC gas, and other fluorocarbon gases.

[0136] [Table 1]

[0137] To achieve high aspect ratio etching that is more perpendicular to the substrate surface, the appropriate gas type can be selected depending on the material that makes up the substrate. For example, if the substrate consists of multiple layers, it is preferable to select and apply the gas type and etching method according to the material of each layer that makes up the substrate.

[0138] (Process of removing metal structures) The process of removing metal structures allows for the removal of metal structures formed on the substrate in the laminate. As shown in (b1) to (c1) and (b2) to (c2) of Figure 3, after etching the surface of the substrate 3 exposed from the etching mask by the etching process, the metal structure is removed by the metal structure removal process, thereby manufacturing a substrate 3 containing the structure onto which the pattern 5 in Figure 2 has been transferred. In the method for manufacturing a substrate according to an embodiment of the present invention, there are no particular limitations on the method for removing the metal structure, and a known method can be appropriately selected depending on the material of the metal structure. For example, known methods such as etching, chemical treatment, physical stripping, and polishing may be employed. For example, a chemical treatment using acid to dissolve the metal structure can remove the metal structure without damaging the substrate surface. [Examples]

[0139] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to the following examples.

[0140] [Example 1] (Pattern formation) A positive-type resist composition (composition described in Example 1 of Japanese Patent Publication No. 2007-304528) was applied to a Si substrate coated with SOC and SOG using a 65 nm spin coater, baked at 90°C for 60 seconds, exposed using an ArF exposure apparatus, subjected to PEB at 85°C for 60 seconds, and developed / etched with butyl acetate to form a pattern with holes of 50 nm depth and 50 nm diameter. (Preparation of metallic materials) A metallic material was prepared by mixing 100 parts by mass of zirconia oxide with 2860 parts by mass of propylene glycol monomethyl ether acetate and adjusting the viscosity. (Metal structure formation) The metal material prepared above was applied to the pattern having the hole shape using a spin coater to a thickness of 40 nm, and then embedded in the holes. The metal material embedded in the holes of the pattern was baked under nitrogen atmosphere conditions of 250°C and 450°C using the Rapid Thermal Annealing process to confirm the embedding and the formation of the metal structure.

[0141] (Pattern removal) A laminate of Example 1 was obtained in which a pattern formed with a positive-type resist composition was removed by dry etching using CO2 gas as the gas species, and a metallic structure was formed on the substrate (Si substrate). The obtained laminate had a metallic pattern with protrusions formed by the metallic structure, with a width of 50 nm, a height of 40 nm, and an aspect ratio of 0.8. (etching) The gas type was changed to a fluorocarbon (CF-based) gas, and the surface of the Si substrate exposed from the metal structure was etched using the metal structure as an etching mask.

[0142] (Metal structure removal) Metal residue remaining on the metal structure after etching was removed with a CF-based gas, and a substrate of Example 1 was obtained, which included a structure with a pattern having a hole shape transferred onto it.

[0143] [Example 2] (Pattern formation) [Formation of guide patterns] A 100 nm thick spin-on carbon (SOC) layer and a 10 nm thick silicon hard mask film were formed in that order on a 12-inch silicon wafer. Then, a resist film was formed on the silicon hard mask film. The resist film was exposed to 193 nm ArF light using an ArF exposure apparatus, and then developed to form the desired resist pattern. Next, the resist film on which the resist pattern was formed was used as a mask, and the silicon hard mask film was etched using fluorine gas. This transferred the pattern to the silicon hard mask film. Next, using the silicon hard mask film on which the pattern was transferred as a mask, the underlying SOC layer was etched with an oxygen-based gas to transfer the pattern and form a guide pattern. The formed guide pattern was a trench pattern with a pitch of 180 nm, and 20 different guide patterns were obtained with trench widths ranging from 55 to 65 nm in 0.5 nm increments. Each guide pattern for each trench width has a pattern area of ​​5 μm × 8 μm.

[0144] [Process (i)] A silicon wafer with the guide pattern formed as described above was coated with the following primer by spin coating (1500 rpm, 30 seconds), and then baked and dried in air at 90°C for 1 minute to form a primer layer with a thickness of 100 nm. A solution of end-modified polystyrene resin in propylene glycol monomethyl ether acetate (PGMEA) (resin concentration 3% by mass) was used as a primer. Next, the primer layer was rinsed with PGMEA for 60 seconds to remove unreacted polymer portions. After this, it was baked at 250°C for 60 seconds. After baking, the thickness of the primer layer formed on the wafer was 2 nm. Next, the resin composition for forming a phase separation structure (solid content concentration 1.2% by mass) described in Example 1 of Japanese Patent Publication No. 2018-100384 was spin-coated (rotation speed 1500 rpm, 30 seconds) to cover the undercoat layer formed on the wafer, and then shook dry to form a PS-PMMA block copolymer layer with a thickness of 30 nm.

[0145] [Step (ii)] Next, the PS-PMMA block copolymer layer was annealed by heating at 250°C for 300 seconds under a nitrogen atmosphere, thereby separating the PS-PMMA phase from the PMMA phase and forming a structure containing a phase-separated structure.

[0146] [Step (iii)] The wafer on which the phase separation structure was formed was subjected to oxygen plasma treatment to selectively remove the PMMA phase, thereby forming a pattern with holes of 25 nm in diameter.

[0147] The laminate and substrate of Example 2 were obtained in the same manner as in Example 1, except for the formation of the above pattern. [Industrial applicability]

[0148] The present invention provides a laminate applicable to a metal mask capable of forming fine patterns with high precision, a method for manufacturing the laminate, and a method for manufacturing a substrate using the laminate.

[0149] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2021-214608 filed on December 28, 2021, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0150] 1. Laminate 2 Metal structures 3 circuit boards 5 patterns 11 Metal Patterns 11a Recess 11b Convex part

Claims

1. A method for manufacturing a laminate comprising a substrate and a metal structure, comprising: a pattern forming step of forming a pattern on the substrate using a resist composition such that at least a portion of the surface of the substrate is exposed; a metal structure forming step of forming the metal structure by applying a metal material into the mold using the pattern as a template; and a pattern removal step of removing the pattern after the formation of the metal structure. The coating in the metal structure formation process is not plating. The aforementioned metallic material is a metal oxide particle or dispersion thereof selected from the group consisting of zirconium oxide, hafnium oxide, aluminum oxide, tungsten, titanium oxide, copper oxide, cuprous oxide, tin oxide, cerium oxide, indium tin oxide, zinc oxide, yttrium oxide, lanthanum oxide, and indium oxide. A method for manufacturing laminates.

2. The method for manufacturing a laminate according to claim 1, wherein the substrate includes at least one selected from the group consisting of a semiconductor layer, a ferromagnetic layer, an insulating layer, a metal layer, an SOC (Spin-on-Carbon) layer, an SOG (Spin-on-Glass) layer, and an electrode.

3. The method for manufacturing a laminate according to claim 1 or 2, wherein the resist composition is a negative-type resist composition.

4. The method for producing a laminate according to claim 1 or 2, wherein the resist composition is a resin composition for forming a phase separation structure.

5. The method for manufacturing a laminate according to claim 1 or 2, wherein the pattern is a hole pattern.

6. The method for manufacturing a laminate according to claim 1 or 2, wherein in the metal structure forming step, the coating is performed such that the height of the metal material is lower than the height of the pattern.

7. The method for manufacturing a laminate according to claim 1 or 2, wherein the coating in the metal structure formation step is coating by a spin coating method.

8. The method for manufacturing a laminate according to claim 1 or 2, wherein the metal structure formation step further includes a firing process after the coating.

9. A method for manufacturing a substrate having a structure onto which the pattern used in the manufacturing method described in claim 1 or 2 has been transferred, comprising: an etching step of using the metal structure as an etching mask and etching the surface of the substrate exposed from the etching mask; and a step of removing the metal structure.

Images