Sublimation film-forming composition and method for manufacturing substrate

Abstract

To provide a sublimation film forming composition excellent in stability of manufacturing substrates.SOLUTION: A sublimation film forming composition contains a sublimation substance and a solvent with which the saturated solubility of the sublimation substance is set to exceed 10 mass%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a sublimation film-forming composition and a method for producing a substrate. [Background technology]

[0002] Various developments have been made so far regarding manufacturing processes for substrates having a concave-convex structure. One such technique is disclosed in Patent Document 1, for example. Patent Document 1 describes a substrate drying method for removing a liquid on a substrate having an uneven pattern formed on its surface and drying the substrate, the method comprising: a sublimable substance filling step of supplying a solution of a sublimable substance to the substrate and filling the recesses of the pattern with the solution; a solvent drying step of drying the solvent in the solution to fill the recesses of the pattern with the sublimable substance in a solid state; and a sublimable substance removal step of heating the substrate to a temperature higher than the sublimation temperature of the sublimable substance to remove the sublimable substance from the substrate (Claim 1 of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-243869 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of investigations by the present inventors, it has been found that the solution of the sublimable substance described in Patent Document 1 has room for improvement in terms of manufacturing stability of the substrate. [Means for solving the problem]

[0005] As a result of further investigations by the present inventors, it has been found that even when a solution containing a sublimable substance and a solvent is used, there is a risk that pattern collapse will occur frequently in the uneven structure on the substrate. Based on this finding, the present inventors have further conducted intensive research and found that in a sublimation film-forming composition containing a sublimable substance and a solvent, by appropriately selecting a solvent having a relatively high dissolving power for the sublimable substance and a relatively high volatility, or by appropriately combining two or more solvents, the occurrence of pattern collapse can be suppressed and the manufacturing stability of the substrate can be improved, and thus the present invention has been completed.

[0006] According to the present invention, a sublimable material; a solvent A1 having a saturated solubility of the sublimable substance exceeding 10% by mass and a boiling point that is 5°C or more lower than the boiling point of the sublimable substance at 1 atmospheric pressure; A sublimable film-forming composition is provided, comprising:

[0007] According to the present invention, A sublimation film-forming composition containing a sublimable substance, a solvent A2 having a saturated solubility of the sublimable substance of more than 10% by mass; and a solvent B2, the content of which in the sublimable film-forming composition is greater than the content of the solvent A2, and the boiling point of which is lower than the boiling point of the sublimable substance at 1 atmospheric pressure and lower than the boiling point of the solvent A2. A sublimable film-forming composition is provided.

[0008] Further, according to the present invention, preparing a substrate having a textured structure on its surface; supplying a sublimation film-forming composition containing a sublimation material to the surface; solidifying the sublimation film-forming composition to form a sublimation film on the surface; sublimating the sublimable substance to remove the sublimable film; Including, The sublimation film-forming composition containing the sublimation substance is the sublimation film-forming composition described above. A method for manufacturing a substrate is provided. [Effects of the Invention]

[0009] According to the present invention, a sublimation film-forming composition that is excellent in stability in the production of substrates and a method for producing substrates are provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1A to 1C are cross-sectional views illustrating an example of a manufacturing process for a substrate. [Figure 2] 1 is an SEM image of a substrate surface in Example 1. [Figure 3] 10 is an SEM image of the substrate surface in Example 3. [Figure 4] 10 is an SEM image of the substrate surface in Example 5. [Figure 5] 10 is an SEM image of the substrate surface in Example 21. [Figure 6] 10 is an SEM image of the substrate surface in Example 22. [Figure 7] 1 is an SEM image of a substrate surface in Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] The sublimation film-forming composition of this embodiment will be outlined below.

[0012] The sublimable film forming composition of the first embodiment includes a sublimable substance and a solvent A1 in which the saturated solubility of the sublimable substance is more than 10 mass % and the boiling point is 5° C. or more lower than the boiling point of the sublimable substance at 1 atmosphere.

[0013] The sublimation film forming composition of the second embodiment includes a sublimation substance, a solvent A2 in which the saturated solubility of the sublimation substance exceeds 10 mass %, and a solvent B2 whose content in the sublimation film forming composition is larger than the content of solvent A2 and whose boiling point is lower than the boiling point of the sublimation substance at 1 atmospheric pressure and lower than the boiling point of solvent A2.

[0014] Such a sublimation film-forming composition of the present embodiment can be suitably used in the manufacturing process of a substrate having a concave-convex structure on its surface, and can suppress pattern collapse in the concave-convex structure of the substrate.

[0015] 1(a) to 1(c) are cross-sectional views showing an example of a manufacturing process for a substrate using a sublimation film-forming composition. FIG. 1(a) shows a process of supplying a sublimation film-forming composition 30 to the surface of a substrate 10 and filling the recesses 24 in the uneven structure 20 with the sublimation film-forming composition 30, FIG. 1(b) shows a process of solidifying the sublimation film-forming composition 30 to form a sublimation film 50, and FIG. 1(c) shows a process of sublimating the sublimable substance and removing the sublimation film 50.

[0016] Taking the manufacturing of semiconductor chips as an example, this manufacturing process involves forming a fine uneven pattern on the surface of a substrate (wafer) through processes such as film deposition, lithography, and etching, followed by wet processing such as a cleaning process using water or an organic solvent to clean the wafer surface, and a drying process to remove any liquids such as cleaning fluids and rinse fluids that have adhered to the wafer during the wet processing. It is known that during such a drying step, deformation or collapse of the fine concave-convex pattern is likely to occur in semiconductor substrates having such a pattern. In order to dry a substrate on which a concave-convex pattern has been formed using a sublimable substance, a step is generally carried out in which the liquid remaining in the concave-convex pattern is replaced with a treatment liquid containing the sublimable substance.

[0017] According to the findings of the present inventors, it has been found that when a sublimation film-forming composition containing a sublimable substance and a solvent is used in a manufacturing process of a substrate having a textured structure, by appropriately selecting a solvent having a relatively high dissolving power for the sublimable substance and a relatively high volatility, or by appropriately combining two or more solvents, the occurrence of pattern collapse in the textured structure of the substrate can be suppressed.

[0018] As shown in the first embodiment, a solvent A1 having an appropriate dissolving power for sublimable substances and an appropriate volatility may be adopted, or as shown in the second embodiment, a solvent A2 having an appropriate dissolving power for sublimable films and a solvent B2 having an appropriate volatility may be used in combination.

[0019] Although the detailed mechanism is not clear, it is thought that by using a highly volatile solvent (solvent A1, solvent B2) that is more volatile than the sublimable substance, film formation ability is improved, while by using a highly soluble solvent (solvent A1, solvent A2) that has a relatively high dissolving power for the sublimable substance, it is possible to suppress the premature and excessive precipitation of the sublimable substance, thereby suppressing pattern collapse that is initiated by the premature precipitation of the sublimable substance.

[0020] Furthermore, in the technical field of substrates having fine uneven structures such as semiconductor wafers, pattern collapse is generally known to refer to a state in which a pattern within a predetermined range collapses in random directions, i.e., so-called planar collapse. However, it has been found that there is a type of pattern collapse that is different from the planar collapse. Streaky collapse basically refers to a state in which a pattern collapses continuously in a predetermined direction. Streaky collapse may also occur in a manner that surrounds a predetermined area where there is no pattern collapse. Even if the area collapse and pattern collapse rate can be suppressed, streaky collapse may still occur.

[0021] According to the findings of the present inventors, it has been found that, among the pattern collapses, streaky collapse can be suppressed by using solvents A1 and A2 having a higher dissolving power for the sublimable substance and / or by using a sublimable substance having a relatively low heat of solidification.

[0022] Although the detailed mechanism is unclear, it is thought that the streaky collapse occurs due to distortion at the crystal grain boundaries of the sublimable film. Therefore, it is thought that the streaky collapse can be suppressed by using a solvent with high solubility to suppress partial crystallization starting from the part where the sublimable substance precipitated early, or by using a sublimable substance with a low heat of solidification to reduce the crystallinity.

[0023] The sublimation film-forming composition of this embodiment can be suitably used as a composition for drying a concave-convex pattern used in the step of drying a concave-convex structure in the process of manufacturing a substrate having a concave-convex structure. The sublimable substance may be one that disappears entirely by a predetermined heat treatment, or one that disappears when left standing at 23°C under 1 atmosphere. In the method for manufacturing a substrate, the sublimable film is not a permanent film that remains permanently on the substrate, but is used as a sacrificial film that is removed in a subsequent step. Therefore, the sublimable film-forming composition can be used as a composition for forming a sublimable sacrificial film.

[0024] The sublimation film-forming composition of this embodiment will be described in detail below.

[0025] (Sublimable substance) The sublimable film-forming composition contains one or more sublimable substances.

[0026] Sublimable materials, as used herein, refer to materials that have a vapor pressure in the solid state. In principle, any substance that is solid and has vapor pressure at a specific temperature can be used as the sublimable substance.

[0027] The lower limit of the freezing point of the sublimable substance is, for example, 5° C. or higher, preferably 20° C. or higher, and more preferably 50° C. or higher under 1 atmosphere. This eliminates the need for extremely low-temperature treatment for freezing the sublimable substance when applied to a substrate manufacturing method, thereby improving the manufacturing stability of semiconductor substrates. On the other hand, the upper limit of the freezing point of the sublimable substance is, for example, 220° C. or less, preferably 200° C. or less, and more preferably 180° C. or less under 1 atmosphere. This eliminates the need for treatment at extremely high temperatures to sublimate the sublimable substance when applied to a substrate manufacturing method, thereby improving the manufacturing stability of semiconductor substrates.

[0028] The lower limit of the heat of solidification of the sublimable substance is not particularly limited, but may be, for example, 1 J / g or more, preferably 5 J / g or more, and more preferably 10 J / g or more. On the other hand, the upper limit of the heat of solidification of the sublimable substance is 200 J / g or less, preferably 100 J / g or less, and more preferably 50 J / g or less, which can prevent streaking.

[0029] The sublimable material may be configured so as to be substantially free of non-volatile substances that become residues after sublimation. Non-volatile substances can be removed from the sublimable material by separation means such as sublimation purification or distillation. "Substantially free" means that the non-volatile substances are contained in 100% by mass of the sublimable material, preferably 1% by mass or less, and preferably 0.5% by mass or less, or unavoidable contamination is acceptable.

[0030] The lower limit of the boiling point of the sublimable substance is, for example, 60° C. or higher, preferably 100° C. or higher, more preferably 110° C. or higher under 1 atmospheric pressure. This makes it possible to stably form a sublimable film containing the sublimable substance. On the other hand, the upper limit of the boiling point of the sublimable substance is, for example, 300°C or less, preferably 280°C or less, more preferably 250°C or less under 1 atmospheric pressure. This facilitates the purification of the sublimable substance. Furthermore, in a normal temperature and normal pressure process, the sublimable substance is easily sublimated, thereby improving production efficiency.

[0031] The boiling point or sublimation point of a sublimable substance containing multiple components is the boiling point or sublimation point of the component with the highest content (mass%) among the components contained in the sublimable substance (however, if there are two or more components with the highest content, the boiling point or sublimation point with the highest temperature is used). The boiling point of the sublimable substance is the initial boiling point defined in JIS K 2254:2018 (ISO 3405). When the sublimation point is commonly used for a substance, the sublimation point is used. The freezing point of a sublimable substance is the solidification start temperature determined using DSC at a rate of -10°C / min. The freezing point of a sublimable substance containing multiple components is the freezing point of the component with the highest content (mass%) among the components contained in the sublimable substance (however, if there are two or more components with the highest content, the freezing point of the one with the higher temperature is used).

[0032] The temperature range in which the sublimable substance is solid and has vapor pressure (hereinafter also referred to as "sublimation temperature range") may be, for example, 10° C. or higher. This makes it possible to solidify the sublimable substance by cooling due to the heat of vaporization of the solvent in the sublimable film-forming composition even when used in an environment of 20 to 25° C., which is the general room temperature in a clean room. Furthermore, when the sublimation temperature range is within the range of 20 to 25°C, sublimation promotion treatment such as heating or decompression becomes unnecessary, and the sublimable substance can be sublimated relatively easily and the sublimable film can be removed while adopting the conditions of the current substrate manufacturing process. The vapor pressure when defining the sublimation temperature range is, for example, 10 Pa or more, preferably 50 Pa or more. In this specification, unless otherwise specified, the symbol "to" indicates that the upper and lower limits are included.

[0033] The sublimable substance is not limited as long as it can be applied to substrate materials such as semiconductors, and examples thereof include non-halogen sublimable substances S1 having a relatively small heat of solidification, non-halogen sublimable substances S2 having a relatively large heat of solidification, sublimable substances S3 having a relatively small difference between the solidification point and the boiling point, halogen-containing sublimable substances S4 containing halogen elements, etc. These may be used alone or in combination of two or more.

[0034] The heat of solidification of the non-halogen sublimable substance S1 is preferably 50 J / g or less, more preferably 40 J / g or less. Since the difference between the solidification point and the boiling point of S1 tends to be relatively large, it can be purified by distillation as a liquid. By using S1, the occurrence of streaky collapse can be suppressed. The heat of solidification of the non-halogen sublimable material S2 is preferably greater than 50 J / g. The difference between the freezing point and the boiling point of the sublimable substance S3 is, for example, 50°C or less, preferably 40°C or less, and more preferably 30°C or less. The halogen-containing sublimable substance S4 may be a fluorine-containing sublimable substance containing a fluorine element as a halogen element. Among these, sublimable substances S1 to S3 are preferably used from the viewpoint of suppressing pattern collapse.

[0035] Examples of sublimable substances include norbornene, norbornane, camphor, pyrazine, 2,3-dichloropyrazine, 2,6-dichloropyrazine, 2,6-dichloropyridine, tetrahydrodicyclopentadiene, dimethyl oxalate, isoborneol, neopentyl alcohol, neopentyl glycol, and ethylene carbonate. Among these, neopentyl alcohol, camphor, pyrazine, tetrahydrodicyclopentadiene, dimethyl oxalate, isoborneol, and ethylene carbonate may be used. These may be used alone or in combination of two or more. Furthermore, when optical isomers exist, one or both may be used.

[0036] The lower limit of the content of the sublimable substance in the sublimation film-forming composition is, for example, 0.1 mass % or more, preferably 0.5 mass % or more, more preferably 0.8 mass % or more, which tends to facilitate uniform solidification of the sublimable substance in the sublimation film-forming composition. On the other hand, the upper limit of the content of the sublimable substance in the sublimation film-forming composition is, for example, 80% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less. This is preferable because it tends to facilitate the cooling effect due to the heat of vaporization of the solvent and facilitate the solidification of the sublimable substance. It is also preferable because it is easy to shorten the time required for sublimation (sublimation time).

[0037] (solvent) The sublimable film-forming composition of this embodiment contains one or more solvents A in which the saturated solubility of the sublimable substance exceeds 10 mass %. Solvent A is defined to include the above-mentioned solvents A1 and A2. By using solvent A having the ability to dissolve the sublimable substance, when the sublimable film-forming composition is supplied onto a substrate through a nozzle, it is possible to prevent the formation of a coagulated body of the sublimable substance at the tip of the nozzle.

[0038] The saturated solubility can be determined from the saturated concentration (mass %) of the sublimable substance dissolved in the solvent. When a plurality of solvents are contained, the saturated solubility is a value individually defined for each solvent. When a sublimation film-forming composition contains multiple kinds of sublimation substances, the saturated solubility is the saturated concentration of the sublimation substance with the highest content (mass%) in the composition (however, when there are two or more kinds of sublimation substances with the highest content, the value of the highest saturated concentration is used).

[0039] The lower limit of the saturated solubility of the sublimable substance in solvent A is more than 10% by mass, preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and still more preferably 60% by mass or more. This can reduce the rate of pattern collapse. On the other hand, the upper limit of the saturated solubility of the sublimable substance in the solvent A may be, for example, 99% by mass or less, or 95% by mass or less.

[0040] The sublimation film-forming composition may also use a solvent A that is compatible with the residual liquid remaining on the substrate surface, which makes it possible to efficiently replace the residual liquid with the sublimation film-forming composition and stably perform the drying process of the residual liquid. Examples of the remaining liquid include common solvents used in semiconductor cleaning processes, specifically water, alcohols having 3 or less carbon atoms (such as methanol, 1-propanol, and 2-propanol), and mixtures thereof. Being compatible means that the amount of the solvent used in the cleaning step that dissolves in 1 part by mass of solvent A is, for example, 0.05 parts by mass or more at 25° C. and 1 atmospheric pressure.

[0041] The sublimable film forming composition of the first embodiment contains one or more solvents A1 in which the saturated solubility of the sublimable substance exceeds 10 mass % and the boiling point is 5° C. or more lower than the boiling point of the sublimable substance at 1 atmosphere. The solvent A1 is selected from among the solvents A, satisfying the condition (1) that the boiling point is at least 5° C. lower than the boiling point of the sublimable substance at 1 atmospheric pressure.

[0042] In the condition (1), (boiling point of the sublimable substance at 1 atmosphere - boiling point of solvent A1) may be 5°C or higher, preferably 50°C or higher, more preferably 80°C or higher, while it may be 200°C or lower, preferably 180°C or lower.

[0043] In this specification, when a plurality of solvents are contained, the boiling point of each solvent is taken as the azeotropic point in the case of an azeotropic solvent, whereas the boiling point individually specified for each solvent is taken as the boiling point in the case of a non-azeotropic solvent.

[0044] In the sublimation film forming composition of the first embodiment, by including at least one of such solvents A1, it is considered that the solvent A1 with high dissolving power can prevent the early precipitation of the sublimation substance from becoming excessive, and the solvent A1 with higher volatility than the sublimation substance can promote the formation of the sublimation film (solidification of the sublimation substance) by the heat of vaporization. This can reduce the pattern collapse rate after the sublimation film is formed and removed, and also can prevent streaky collapse.

[0045] The sublimable film-forming composition of the present embodiment may contain one or more solvents B having a boiling point lower than the boiling point of the sublimable substance at 1 atmosphere, in addition to the solvent A. Solvent B is defined to include the solvents B1 and B2.

[0046] The sublimable film-forming composition of the first embodiment may contain one or more of the above-mentioned solvents A1 and one or more of solvents B1 having a boiling point lower than that of solvent A1. The saturated solubility of the sublimable substance in solvent B1 is not particularly limited as long as it has a boiling point lower than that of solvent A1, but solvent B1 can be used even if it is lower than the saturated solubility of solvent A1. The difference between the boiling points of solvent A1 and solvent B1 is, for example, 5°C or higher, preferably 10°C or higher, more preferably 15°C or higher, and may be 200°C or lower, or 150°C or lower. The boiling point of the solvent B1 is, for example, 15°C to 85°C, preferably 20°C to 80°C, and more preferably 25°C to 70°C.

[0047] The lower limit of the content of the solvent A1 in the sublimation film-forming composition is, for example, 0.5% by mass or more, preferably 0.8% by mass or more, and more preferably 0.9% by mass or more. In addition, when the sublimation film-forming composition uses solvent A1 as the main solvent, the content of solvent A1 in the sublimation film-forming composition may be 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. In this case, when another solvent is used, it is preferable to use solvent B1 as the solvent. In this case, the content of solvent A1 in the sublimation film-forming composition may be greater than that of solvent B1. On the other hand, the upper limit of the content of solvent A1 may be, for example, 99.9 mass % or less, preferably 99.5 mass % or less, more preferably 99.2 mass % or less, when the solvent of the sublimation film forming composition substantially contains only solvent A1 and / or when the main component of the solvent of the sublimation film forming composition is solvent A1. Also, when the sublimation film forming composition contains solvent A1 and solvent B1 and the main component of the solvent is not A1, for example, the content of solvent A1 in the sublimation film forming composition may be less than 50 mass %, preferably 30 mass % or less, more preferably 15 mass % or less.

[0048] The sublimation film forming composition of the second embodiment includes one or more solvents A2 in which the saturated solubility of the sublimation substance exceeds 10 mass %, and one or more solvents B2 in which the content in the sublimation film forming composition is larger than the content of solvent A2 and the boiling point is lower than the boiling point of the sublimation substance at 1 atmospheric pressure and lower than the boiling point of solvent A2.

[0049] Solvent A2 is selected from the above-mentioned solvents A. (Boiling point of sublimable substance at 1 atmosphere - boiling point of solvent A2) may be 0°C, or may be 0°C or higher and lower than 5°C, or may be 5°C or higher and 200°C or lower. From the viewpoint of facilitating solidification of the sublimable substance, for example, 0°C or higher and 200°C or lower may be preferable, and 5°C or higher and 200°C or lower may be more preferable.

[0050] Solvent B2 is a solvent that can promote the formation of a sublimable film by volatilizing earlier than solvent A2, and as long as its boiling point is lower than that of solvent A2 and the boiling point of the sublimable substance, the saturated solubility of the sublimable substance is not particularly limited, and even if the saturated solubility of the sublimable substance in solvent B2 is lower than the saturated solubility of the sublimable substance in solvent A2, it can be used. However, the content of solvent B2 in the sublimation film-forming composition is greater than the content of solvent A2. Preferably, solvent B2 may be contained as a main component in the sublimation film-forming composition. The main component means that the lower limit of the content of solvent B2 in the sublimation film-forming composition is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more. The upper limit of the content of solvent B2 may be, for example, 99.8% by mass or less, 99.5% by mass or less, or 99% by mass or less. In the sublimation film-forming composition containing solvent B2 as the main component, the content of solvent A2 is, for example, 0.1 to 30% by mass, and preferably 0.5 to 10% by mass.

[0051] In the sublimation film-forming composition of the second embodiment, by containing at least one each of such solvents A2 and B2, solvent B2 is relatively volatilized, and the heat of vaporization promotes the formation of the sublimation film (solidification of the sublimation material). At this time, the sublimation material and solvent A2 remain, and since solvent A2 can dissolve the sublimation material in this residue, it is thought that it is possible to suppress excessive early precipitation of the sublimation material. As a result, after the sublimation film is formed and removed, the pattern collapse rate can be reduced, and in addition, streaky collapse can also be suppressed. Furthermore, it was found that the sublimation film-forming composition of the second embodiment has a tendency to particularly reduce the pattern collapse rate in the examples described below. By including the solvent B2 as a main component in the sublimation film forming composition of the second embodiment, it becomes possible to reduce the time required to form the sublimation film, and the manufacturing cost of the above-mentioned substrate can also be reduced.

[0052] Furthermore, the difference between the boiling points of solvent A2 and solvent B2 is not particularly limited as long as solvent A2 remains after solvent B2 evaporates, but is, for example, 5°C or higher, preferably 10°C or higher, more preferably 15°C or higher, and even more preferably greater than 20°C, and may also be 200°C or lower, or 150°C or lower.

[0053] The upper limit of the boiling point of solvent B2 is, for example, 85°C or lower, preferably 80°C or lower, and more preferably 70°C or lower. On the other hand, the lower limit of the boiling point of solvent B2 may be, for example, 15°C or higher, preferably 20°C or higher, and more preferably 25°C or higher.

[0054] In the first embodiment, when two or more kinds of solvents A1 are contained, for example, the second or subsequent solvents A1 may be selected from solvents A1 having a saturated solubility of the sublimable substance of 40% by mass or more and a boiling point of 200°C or less, and preferably from solvents A1 having a saturated solubility of the sublimable substance of 75% by mass or more and a boiling point of 180°C or less.

[0055] In the second embodiment, when two or more kinds of solvent A2 and / or solvent B2 are contained, as an example, the second or subsequent solvent A2 may be selected from those in which the saturated solubility of the sublimable substance in the solvent A2 is 40% by mass or more and the boiling point is the boiling point of the sublimable substance or less, preferably from those in which the saturated solubility of the sublimable substance is 50% by mass or more and the boiling point is 210°C or less, more preferably from those in which the saturated solubility of the sublimable substance is 60% by mass or more and the boiling point is 200°C or less, and even more preferably from those in which the saturated solubility of the sublimable substance is 75% by mass or more and the boiling point is 180°C or less. Furthermore, when two or more solvents A2 are contained and one or more solvents B2 are contained, a smaller boiling point difference between the solvents A2 is preferred because solvent B2 is more likely to remain when it volatilizes. The boiling point difference is not particularly limited as long as it can exert its effect as solvent A2. For example, the difference between the highest and lowest boiling points of the two or more solvents A2 may be preferably 20°C or less, more preferably 15°C or less, and even more preferably 10°C or less. That is, the difference in boiling point between the second or subsequent solvents A2 and the first solvent A1 may be, for example, 10°C or less, 15°C or less, or 20°C or less. In this case, the boiling point of solvent B2 is lower than the smallest boiling point of solvent A2. The second and subsequent solvents B2 may be selected from those having a boiling point of, for example, 83°C or lower, preferably 80°C or lower, more preferably 70°C or lower.

[0056] Examples of solvents used in the sublimation film-forming composition include hydrocarbons, ethers, alcohols, ketones, esters, sulfoxides, and nitrogen-containing compounds. Each of these solvents may have one or more halogen atoms, such as fluorine or chlorine atoms, in the molecule. These may be used alone or in combination of two or more.

[0057] Examples of hydrocarbons that can be used include alkanes or cycloalkanes having 4 to 10 carbon atoms, alkenes or cycloalkenes having 4 to 10 carbon atoms, and aromatic hydrocarbons having 6 to 10 carbon atoms. Specific examples of hydrocarbons include pentane, 3-methylpentane, hexane, heptane, octane, nonane, decane, isododecane, cyclopentane, cyclohexane, methylcyclohexane, 1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethylene, cis-1-chloro-3,3,3-trifluoropropene (1233Z), trans-1-chloro-3,3,3-trifluoropropene (1233E), toluene, benzene, and xylene.

[0058] As the ethers, for example, linear or cyclic ether compounds having 3 to 10 carbon atoms are used. Specific examples of ethers include tetrahydrofuran, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, tert-butyl methyl ether, dioxane, 1,1,1,2,2,3,3,4,4-nonafluorobutyl methyl ether (Novec 7100), ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, and propylene glycol dimethyl ether.

[0059] As the alcohol, for example, primary, secondary or tertiary alcohols having 1 to 10 carbon atoms are used. Specific examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol (IPA), 1-butanol, 2-butanol, cyclopentanol, cyclohexanol, 2-methyl-2-butanol, 4-methyl-2-pentanol, ethylene glycol, propylene glycol, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoro-2-propanol, and 1,3-propanediol.

[0060] As the ketones, for example, ketone compounds having 3 to 6 carbon atoms are used. Specific examples of ketones include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, and methyl butyl ketone.

[0061] Examples of the esters include linear or cyclic ester compounds having 3 to 6 carbon atoms. Specific examples of esters include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, methyl lactate, ethyl lactate, ethyl acetoacetate, ethyl trifluoroacetate, γ-butyrolactone, ethylene glycol acetate, propylene glycol acetate, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate. Examples of sulfoxides include dimethyl sulfoxide. Examples of the nitrogen-containing compound include formamide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and pyridine.

[0062] As solvent A1, solvent A2, solvent B1, and solvent B2, one or more solvents may be selected from the above solvents depending on the sublimable substance contained in the sublimable film-forming composition. From the viewpoint of achieving both high dissolving power for the sublimation agent and compatibility with water or alcohols having 3 or less carbon atoms, which are the residual liquid remaining on the substrate surface, solvent A1 and solvent A2 preferably contain at least one selected from the group consisting of ethers, alcohols, ketones, esters, and hydrocarbons having one or more halogen atoms such as fluorine or chlorine atoms in the molecule. Specific examples of these solvents include tetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-butanol, acetone, methyl acetate, ethyl acetate, 1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethylene, cis-1-chloro-3,3,3-trifluoropropene, and trans-1-chloro-3,3,3-trifluoropropene. Among these, more preferred are methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, 2-methyl-2-butanol, acetone, methyl acetate, cis-1-chloro-3,3,3-trifluoropropene, and trans-1-chloro-3,3,3-trifluoropropene. From the viewpoint of achieving both high volatility and compatibility with water or an alcohol having 3 or less carbon atoms, which is the residual liquid remaining on the substrate surface, solvents B1 and B2 preferably contain at least one selected from the group consisting of hydrocarbons, ethers, alcohols, ketones, and esters. Specific examples of these include pentane, 3-methylpentane, hexane, heptane, cyclopentane, cyclohexane, methylcyclohexane, 1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethylene, cis-1-chloro-3,3,3-trifluoropropene, trans-1-chloro-3,3,3-trifluoropropene, toluene, benzene, xylene, diethyl ether, dipropyl ether, diisopropyl ether, tetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, acetone, methyl acetate, and ethyl acetate. Among these, more preferred are pentane, hexane, cyclopentane, cyclohexane, methylcyclohexane, cis-1-chloro-3,3,3-trifluoropropene, trans-1-chloro-3,3,3-trifluoropropene, diethyl ether, tetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, acetone, and methyl acetate.

[0063] (Other solvents) The sublimation film-forming composition may further contain solvent C in addition to the above-mentioned solvents A1, A2, B1 and B2, for the purpose of adjusting the wettability to the substrate and / or the uneven pattern, within the range that does not impair the effects of the present invention, or may be configured so that the sublimation film-forming composition does not substantially contain solvent C. Examples of solvent C include water, hydrocarbons, esters, ethers, ketones, sulfoxide solvents, alcohols, polyhydric alcohol derivatives, and nitrogen-containing compounds, and refer to solvents that do not fall under the category of solvents used as essential components. Examples of the hydrocarbons include toluene, benzene, xylene, pentane, 3-methylpentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, methylcyclohexane, 1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethylene, cis-1-chloro-3,3,3-trifluoropropene (1233Z), trans-1-chloro-3,3,3-trifluoropropene (1233E), etc. Examples of the esters include ethyl acetate, butyl acetate, methyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, methyl lactate, ethyl lactate, ethyl acetoacetate, ethyl trifluoroacetate, γ-butyrolactone, etc. Examples of the ethers include diethyl ether, dipropyl ether, diisopropyl ether, ddibutyl ether, Examples of the ketones include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, etc.; an example of the sulfoxide solvents includes dimethyl sulfoxide, etc.; examples of the alcohols include methanol, ethanol, 1-propanol, 2-propanol, butanol, 4-methyl-2-pentanol, ethylene glycol, 2-methyl-2-butanol, 4-methyl-2-pentanol, ethylene glycol, propylene glycol, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 1,Examples of derivatives of the polyhydric alcohols include diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Examples of the nitrogen-containing compounds include formamide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and pyridine, among which solvents not corresponding to Solvents A1, A2, B1, and B2 are exemplified.

[0064] The lower limit of the total content of the solvent in the sublimation film-forming composition is, for example, 20% by mass or more, preferably 50% by mass or more, and more preferably 60% by mass or more, which is preferable because it tends to facilitate the cooling effect due to the heat of vaporization of the solvent and facilitate the solidification of the sublimation material. On the other hand, the upper limit of the total content of the solvent in the sublimation film-forming composition is, for example, 99.9 mass % or less, preferably 99.5 mass % or less, and more preferably 99.2 mass % or less, which is preferable because it tends to facilitate the solidification of the sublimation substance uniformly on the substrate.

[0065] The sublimation film-forming composition is a liquid, preferably a solution, at least when supplied to the substrate surface. From the viewpoint of easy and stable supply, it is preferably a liquid (preferably a solution) at -15°C to 50°C, and more preferably a liquid (preferably a solution) at 0°C to 40°C. Furthermore, from the viewpoint of simplifying the device configuration by eliminating the need for heat retention or heating in the discharge mechanism, it is particularly preferable that it is a liquid (preferably a solution) at 20°C to 30°C. From the viewpoint of ease of handling (production, storage, transportation, etc.), the compound may be a liquid (preferably a solution) at −15° C. to 50° C., and more preferably a liquid (preferably a solution) at 0° C. to 40° C. Furthermore, from the viewpoint of simplifying the device configuration, such as eliminating the need for warming or heating of the liquid transfer mechanism or storage container, it is particularly preferable that the compound be a liquid (preferably a solution) at 20° C. to 30° C.

[0066] (Substrate manufacturing method) As shown in FIG. 1, an example of a method for manufacturing a substrate of this embodiment includes the steps of preparing a substrate 10 having a concave-convex structure 20 on its surface, supplying a sublimation film-forming composition 30 containing a sublimation substance onto the surface (FIG. 1(a)), solidifying the sublimation film-forming composition 30 to form a sublimation film 50 on the surface (FIG. 1(b)), and sublimating the sublimation substance to remove the sublimation film 50 (FIG. 1(c)).

[0067] As the sublimation film-forming composition 30 containing a sublimation substance in FIG. 1(a), the sublimation film-forming composition of this embodiment may be used, or the sublimation film-forming composition of the first embodiment or the second embodiment may be used. The sublimation film-forming composition of the present embodiment is used to prevent the pattern collapse of the concave-convex structure 20 formed on the substrate 10.

[0068] The method for manufacturing the substrate will be described in detail below. In the above-described step of preparing the substrate 10, the following method, which is one example of a method for forming the uneven structure 20 on the surface of the substrate 10, may be used. First, a resist is applied to the wafer surface, and then the resist is exposed through a resist mask. Either the exposed or unexposed resist is removed to create a resist with the desired concave-convex pattern. Alternatively, a resist with a concave-convex pattern can be obtained by pressing a mold with a pattern against the resist. Next, the wafer is etched. At this time, the substrate surface corresponding to the concave portions of the resist pattern is selectively etched. Finally, the resist is peeled off to obtain a wafer (substrate 10) with a concave-convex structure 20 on its surface.

[0069] There are no particular restrictions on the wafer on which the concave-convex structure 20 is formed and the material of the concave-convex structure 20, and various types of wafers can be used, such as silicon wafers, silicon carbide wafers, wafers composed of multiple components including silicon element, sapphire wafers, various compound semiconductor wafers, plastic wafers, etc. The concave-convex structure 20 can also be made of silicon-based materials such as silicon oxide, silicon nitride, polycrystalline silicon, and single-crystalline silicon, metal-based materials such as titanium nitride, tungsten, ruthenium, tantalum nitride, and tin, combinations of these materials, resist (photoresist) materials, etc.

[0070] 1(a) is a cross-sectional view showing an example of a concave-convex pattern 20. In the cross-sectional structure (in the substrate thickness direction) of the concave-convex pattern 20, at least one of the pattern dimensions of its width and height, or in the three-dimensional structure (three-dimensional coordinates of X, Y, and Z) of the concave-convex pattern 20, at least one of the pattern dimensions of its width (length in the X-axis direction), height (length in the Y-axis direction), and depth (length in the Z-axis direction) may be, for example, 30 nm or less, 20 nm or less, or 10 nm or less. Even when a substrate 10 having such a fine concave-convex pattern 20 is used, the pattern collapse rate can be reduced by using the drying composition of this embodiment. 1, the inclination of the concave-convex pattern 20 is parallel to (does not intersect with) the thickness direction of the substrate, but the drying composition of this embodiment can also be suitably used when the inclination of the concave-convex pattern 20 is not parallel to the thickness direction of the substrate. The above-mentioned "not parallel" means, for example, that in the cross-sectional structure of FIG. 1, the inclination of the concave-convex pattern 20 is perpendicular to the thickness direction of the substrate, or the inclination of the concave-convex pattern 20 intersects (except perpendicular to) the thickness direction of the substrate.

[0071] Such a sublimation film-forming composition is suitable for use in treating a substrate 10 having a relief structure 20 with a pattern dimension of 30 nm or less, preferably 20 nm or less.

[0072] The lower limit of the aspect ratio of the protrusions 22 may be, for example, 3 or more, 5 or more, or 10 or more. Pattern collapse can be suppressed even in the concavo-convex structure 20 having the protrusions 22 with a fragile structure. On the other hand, the upper limit of the aspect ratio of the protrusions 22 is not particularly limited, but may be 100 or less. The aspect ratio of the protrusions 22 is expressed as the value obtained by dividing the height of the protrusions 22 by the width of the protrusions 22 .

[0073] After the formation of the concave-convex structure 20, the surface of the substrate 10 is washed with a washing liquid such as water or an organic solvent (washing step).

[0074] After the cleaning step, as shown in FIG. 1(a), a liquid sublimation film-forming composition is supplied to the concave-convex structure 20 formed on the surface of the substrate 10. The sublimation film-forming composition supplied at this time is preferably a liquid in an environment of 20 to 30°C, more preferably a solution. The composition may be supplied so as to fill part or all of the recesses 24 of the concave-convex structure 20 (this may be referred to as a "sublimation film-forming composition supplying step", or simply as a "filling step", or a "supplying step"). The supplying may be carried out, for example, in an environment of 20 to 30°C.

[0075] The method of supplying the sublimation film-forming composition can be any known method, but for example, a single wafer method, typified by a spin method, in which wafers are held substantially horizontally and rotated one by one while the composition is supplied near the center of rotation, thereby displacing cleaning liquid and the like retained in the uneven pattern of the wafer and filling the composition, or a batch method in which multiple wafers are immersed in a composition tank, displacing cleaning liquid and the like retained in the uneven pattern of the wafer, and filling the composition, may be used.

[0076] After the cleaning process, the cleaning liquid remains on the surface of the substrate 10. By selecting a cleaning liquid that dissolves in the sublimation film-forming composition, the remaining cleaning liquid can be relatively easily replaced with the sublimation film-forming composition. Therefore, it is usually preferable to use at least one selected from alcohols having 3 or less carbon atoms, such as methanol, 1-propanol, and 2-propanol, as the cleaning liquid.

[0077] The sublimable substance used in the sublimable film-forming composition may be purified in advance by a separation means such as sublimation purification or distillation.

[0078] After the filling step, as shown in Fig. 1(b), the sublimable substance in the sublimable film forming composition 30 is solidified, and a sublimable film 50 containing the solidified body of the sublimable substance is formed on the concave-convex structure 20 (this step may be referred to as a "sublimable film forming step" or simply as a "solidifying step"). The sublimable film 50 filled inside the recesses 24 of the concave-convex structure 20 can prevent the pattern of the concave-convex structure 20 from collapsing.

[0079] In the solidification step, the solid sublimable substance may be precipitated by cooling, or the solvent may be evaporated by heating or applying appropriate environmental conditions, and the solid sublimable substance may be precipitated by the heat of vaporization. In this embodiment, by appropriately selecting the solvents A1, A2, B1, and B2 used in the sublimation film-forming composition as described above, it is possible to volatilize (dry) the solvents, for example, at room temperature and normal pressure (20°C to 25°C, 1 atm). Furthermore, by setting the lower limit of the freezing point of the sublimable substance to the above-mentioned lower limit or higher, extreme cooling becomes unnecessary, and the sublimable substance can be solidified by the heat of vaporization of the solvent. When the solidification step is carried out at room temperature and normal pressure, the evaporation of the solvent may be promoted as needed, for example, by rotating the substrate 10 or by blowing an inert gas onto the substrate 10.

[0080] After the solidification process, as shown in FIG. 1(c), the solid sublimable substance is sublimated to remove the sublimable film 50 on the uneven structure 20 (sometimes referred to as the "process for removing the sublimable film" or simply the "removal process"). The method for sublimating the sublimable substance can be appropriately selected depending on the boiling point of the sublimable substance. For example, when the boiling point is relatively low, the sublimation may be carried out at room temperature and atmospheric pressure, but if necessary, heating or decompression may be carried out.

[0081] 1 is directed to a wafer pattern, but the present invention is not limited thereto. In the method for producing a substrate of this embodiment, a resist pattern is targeted, and by using the sublimation film-forming composition of the present invention in the cleaning and drying process, it is also possible to prevent the resist pattern from collapsing. Although the above-described manufacturing method is performed after the cleaning step, the supplying step is not limited to this, and may be performed after various treatments performed on the concave-convex structure 20. For example, the supplying step may be performed after treating the concave-convex structure 20 with a chemical solution for forming a water-repellent protective film. In addition to the above-described steps, the method for manufacturing a substrate may also include one or a combination of two or more known treatments. For example, a surface treatment such as a plasma treatment may be performed after the above-described removal step.

[0082] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. Furthermore, in this specification, ordinal numbers such as "first," "second," and "third," and symbols such as "A" and "B" are used merely to distinguish between similarly named configurations, unless otherwise specified, and do not imply any particular characteristics of the configurations (e.g., order or importance). [Example]

[0083] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the descriptions of these examples.

[0084] <Preparation of Sublimation Film-Forming Composition> (Examples 1 to 31, Comparative Example 1) A sublimation film-forming composition was prepared by mixing and dissolving a sublimation agent (sublimable substance) in a solvent at about 25°C so as to obtain the sublimation agent concentration (mass%) shown in Table 1. Table 1 shows the boiling point (°C) of the sublimation agent, the boiling point (°C) of the solvent, and the saturated solubility (mass%) of the sublimation agent in the solvent.

[0085] The saturated solubility means the saturated concentration of the sublimation agent dissolved in the solvent, and was measured as follows. First, a mixture was prepared by mixing the sublimation agent and solvent in a mass ratio of approximately 3:1, heating to 40°C, and then cooling to room temperature (approximately 25°C). If the mixture became a coexistence of solid and liquid at room temperature, 10 μL of the liquid portion was sampled using a microsyringe, diluted 100 times (by volume) with dilution solvent, analyzed by gas chromatography, and converted to a mass ratio to obtain the saturated solubility (mass%). If no precipitation of the sublimation agent occurred at room temperature and a homogeneous solution was obtained, the amount of sublimation agent relative to the solvent was increased and the same procedure was repeated. Furthermore, if the liquid portion was small at room temperature and sampling with a microsyringe was difficult, the amount of solvent relative to the sublimation agent was increased and the same procedure was repeated. The mass ratio based on gas chromatography was calculated by attaching a capillary column (Model TC-1, GL Sciences, 30 m length, 5 μm liquid phase thickness, 0.32 mm inner diameter) to a Model GC-2010 gas chromatograph manufactured by Shimadzu Corporation, and converting the area ratio detected by the FID detector into a mass ratio based on the area ratio of a diluent in which the sublimation agent and the solvent were dissolved at 1% by mass. The diluent solvent used in gas chromatography must be selected so that the peaks of the sublimation agent and the solvent to be measured are sufficiently separated by gas chromatography. Specifically, a solvent with a development time on the chromatogram that is 0.1 minutes or more apart was selected.

[0086] (Examples 32 to 64, Comparative Examples 2 and 3) A sublimation film-forming composition was prepared by mixing and dissolving a sublimation agent (sublimable substance) in at least one of solvents 1 to 3 at about 25°C so as to obtain the mixing ratio (mass%) shown in Table 2. The boiling points (°C) of the sublimation agent and the boiling points (°C) of the solvents are shown in Table 2, and the saturated solubility (mass%) of the sublimation agent in the solvent is shown in Table 4.

[0087] (Examples 65 to 75) Sublimation film-forming compositions were prepared by mixing and dissolving sublimation agent 1 and / or sublimation agent 2 (sublimable substances) in solvent 1 and solvent 2 at about 25°C so as to achieve the mixing ratio (mass%) shown in Table 3. The boiling points (°C) of the sublimation agents and the boiling points (°C) of the solvents are shown in Table 3, and the saturated solubility (mass%) of the sublimation agents in the solvents is shown in Table 4. The solidification heats and solidification points of the sublimation agents listed in Tables 1 to 4 are shown in Table 5.

[0088] <Substrate manufacturing> First, a silicon substrate having an uneven surface with a plurality of roughly cylindrical convex portions with an aspect ratio of 22 in a cross-sectional view and a pattern width of 19 nm, at a pitch of 90 nm (the total distance between the width of the convex portions and the adjacent spacing between the convex portions), was cut into a size of 1 cm x 1.5 cm to prepare an evaluation substrate. Next, the surface of the uneven structure of the evaluation substrate was dry cleaned by UV / O3 irradiation. Subsequently, the evaluation substrate was placed on a spin coater, and 2-propanol was supplied to hold the liquid (2-propanol) in the recesses of the concave-convex structure. Subsequently, the sublimation film-forming composition in a solution state obtained above was dropped onto the surface of the uneven structure, and the remaining liquid of 2-propanol was replaced with the sublimation film-forming composition (step (I)). Subsequently, the evaluation substrate was rotated at a rotation speed of 100 rpm using a spin coater, and the formation of a sublimable film (a solidified film of the sublimable substance) was visually confirmed (step (II)). Subsequently, rotation was continued until disappearance of the sublimable film was confirmed visually (step (III)). The above steps (I) to (III) were carried out at 23 to 24° C. under a nitrogen atmosphere at 1 atmosphere. Thereafter, the evaluation substrate obtained after step (III) was observed with a scanning electron microscope (SEM) (SU8010, manufactured by Hitachi High-Technologies Corporation) to evaluate the rate of collapse of convex portions (pattern collapse) in the concave-convex structure (pattern collapse rate). The "pattern collapse rate" was determined by taking an electron microscope image (secondary electron image) of the center of the evaluation substrate using an SEM at a magnification such that 500 to 600 convex portions were included in the field of view, counting the number of convex portions that had collapsed in the obtained image, and calculating the percentage as the proportion of the total number of convex portions in the field of view. The values ​​were rounded off to the nearest 10 in accordance with JIS Z 8401.

[0089] 2 to 7 show SEM images obtained in Example 1, Example 3, Example 5, Example 21, Example 22, and Comparative Example 1, respectively. Planar collapse occurred in Comparative Example 1 and Example 1, while no planar collapse occurred in Examples 3 and 5, but some streaky collapse occurred, and Examples 21 and 22 showed little streaky collapse.

[0090] In Table 3, the boiling point of isoborneol is the sublimation point. In the table, 1233Z is an abbreviation for cis-1-chloro-3,3,3-trifluoropropene, Novec (registered trademark) 7100 is synonymous with Novec 7100, and N71 is an abbreviation for Novec (registered trademark) 7100.

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] [Table 4]

[0095] [Table 5]

[0096] The sublimation film-forming compositions of Examples 1 to 31 showed a suppressed pattern collapse rate compared to Comparative Example 1, and the sublimation film-forming compositions of Examples 32 to 75 showed a suppressed pattern collapse rate compared to Comparative Examples 2 and 3. Some of the Examples showed results in which the occurrence of streaky collapse was suppressed. Such sublimation film-forming compositions of Examples 1 to 75 can be suitably used in the manufacturing process of substrates having a textured structure, and can improve the manufacturing stability of the substrates.

[0097] This application claims priority based on Japanese Patent Application No. 2020-046815, filed on March 17, 2020, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0098] 10 Substrate 20 Uneven structure 22 Convex part 24 recess 30 Sublimable film forming composition 50 Sublimable membrane

Claims

1. a sublimable material; a solvent A1 having a saturated solubility of the sublimable substance exceeding 10% by mass and a boiling point that is 5°C or more lower than the boiling point of the sublimable substance at 1 atmospheric pressure; Including, the sublimable substance is at least one selected from the group consisting of norbornene, norbornane, pyrazine, 2,3-dichloropyrazine, 2,6-dichloropyrazine, 2,6-dichloropyridine, tetrahydrodicyclopentadiene, dimethyl oxalate, isoborneol, neopentyl alcohol, neopentyl glycol, and ethylene carbonate; The sublimation film-forming composition, wherein the solvent A1 is at least one selected from the group consisting of tetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-butanol, acetone, methyl acetate, ethyl acetate, 1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethylene, cis-1-chloro-3,3,3-trifluoropropene, and trans-1-chloro-3,3,3-trifluoropropene.

2. The sublimation film-forming composition according to claim 1, A sublimable film-forming composition comprising a solvent B1 having a boiling point lower than that of the solvent A1.

3. The sublimation film-forming composition according to claim 2, The sublimation film-forming composition, wherein the solvent B1 is at least one selected from the group consisting of pentane, 3-methylpentane, hexane, heptane, cyclopentane, cyclohexane, methylcyclohexane, 1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethylene, cis-1-chloro-3,3,3-trifluoropropene, trans-1-chloro-3,3,3-trifluoropropene, toluene, benzene, xylene, diethyl ether, dipropyl ether, diisopropyl ether, tetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, acetone, methyl acetate, and ethyl acetate.

4. The sublimation film-forming composition according to any one of claims 1 to 3, The content of the solvent A1 in the sublimation film-forming composition is 50 mass % or more.

5. The sublimation film-forming composition according to any one of claims 1 to 4, A sublimation film-forming composition, wherein the heat of solidification of the sublimation material is 200 J / g or less.

6. The sublimation film-forming composition according to any one of claims 1 to 5, The sublimable film-forming composition, wherein the freezing point of the sublimable substance at 1 atmospheric pressure is 5°C or higher.

7. The sublimation film-forming composition according to any one of claims 1 to 6, A sublimable film-forming composition, wherein the boiling point of the sublimable substance at 1 atmospheric pressure is 300°C or less.

8. The sublimation film-forming composition according to any one of claims 1 to 7, A sublimation film-forming composition, wherein the content of the sublimation substance in the sublimation film-forming composition is 80 mass % or less.

9. The sublimation film-forming composition according to any one of claims 1 to 8, A sublimation film-forming composition used to suppress pattern collapse of a relief structure formed on a substrate.

10. The sublimation film-forming composition according to claim 9, A sublimation film-forming composition for use in treating a substrate having a relief structure with a pattern dimension of 30 nm or less.

11. The sublimation film-forming composition according to claim 10, A sublimation film-forming composition used to treat a substrate having a relief structure with a pattern dimension of 20 nm or less.

12. preparing a substrate having a textured structure on its surface; supplying a sublimation film-forming composition containing a sublimation material to the surface; solidifying the sublimation film-forming composition to form a sublimation film on the surface; sublimating the sublimable substance to remove the sublimable film; Including, The sublimation film-forming composition containing the sublimation substance is the sublimation film-forming composition according to any one of claims 1 to 8. A method for manufacturing a substrate.

13. The method for manufacturing a substrate according to claim 12, The method for manufacturing a substrate, wherein the substrate has, on its surface, the uneven structure having a pattern dimension of 30 nm or less.

14. The method for manufacturing a substrate according to claim 13, The method for manufacturing a substrate, wherein the substrate has, on its surface, the uneven structure having a pattern dimension of 20 nm or less.

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