Sublimation film-forming composition and method for producing substrate

Abstract

This sublimable film formation composition includes a sublimable substance and a solvent in which the saturation solubility of the sublimable substance is greater than 10 mass%.

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 known from Patent Document 1. Patent Document 1 describes a substrate drying method for removing 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] JP 2012-243869 A Summary of the Invention [Problem to be solved by the invention]

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

[0005] As a result of further investigations, the present inventors have 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 knowledge, the present inventor has further studied intensively and found that in a sublimation film forming composition containing a sublimation material and a solvent, by appropriately selecting a solvent having a relatively high dissolving power of the sublimation material and a relatively high volatility, or by appropriately combining two or more kinds of 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 saturation solubility of the sublimable substance exceeding 10% by mass and a boiling point 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 comprising a sublimable material, A solvent A2 having a saturation 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, A step of preparing a substrate having a relief structure on a surface thereof; supplying a sublimable film-forming composition containing a sublimable material onto the surface; solidifying the sublimation film forming composition to form a sublimation film on the surface; sublimating the sublimable material to remove the sublimable film; Including, The sublimation film forming composition containing the sublimation substance is the above-mentioned sublimation film forming composition, A method for manufacturing a substrate is provided. Effect of the Invention

[0009] According to the present invention, there are provided a sublimation film-forming composition having excellent stability in the production of a substrate, and a method for producing a substrate. [Brief description of the drawings]

[0010] [Figure 1] 1A to 1C are cross-sectional views illustrating an example of a manufacturing process for a substrate. [Diagram 2] 2 is a SEM image of a substrate surface in Example 1. [Diagram 3] 1 is a SEM image of a substrate surface in Example 3. [Figure 4] 13 is an SEM image of a substrate surface in Example 5. [Diagram 5] 1 is an SEM image of a substrate surface in Example 21. [Figure 6] 1 is an SEM image of a substrate surface in Example 22. [Figure 7] 1 is an SEM image of a substrate surface in Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The sublimation film forming composition of the present 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 saturation 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 atmospheric pressure.

[0013] The sublimable film forming composition of the second embodiment includes a sublimable substance, a solvent A2 in which the saturation solubility of the sublimable substance is more than 10 mass %, and a solvent B2 whose content in the sublimable film forming composition is greater than the content of the solvent A2 and whose boiling point is less than the boiling point of the sublimable substance at 1 atmospheric pressure and less than the boiling point of the 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 an uneven surface structure, and can suppress pattern collapse in the uneven surface structure of the substrate.

[0015] 1(a) to (c) are cross-sectional views showing an example of a process for producing a substrate using a sublimation film-forming composition. FIG. 1(a) shows a process of supplying a sublimation film-forming composition 30 onto 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] The manufacturing process of semiconductor chips will be explained as an example. In this manufacturing process, a fine uneven pattern is formed on the surface of a substrate (wafer) through film formation, lithography, etching, etc., and then wet processing such as a cleaning process using water or an organic solvent is performed to clean the wafer surface, and a drying process is also performed to remove liquids such as cleaning liquids and rinsing liquids that have adhered to the wafer during the wet processing. It is known that during such a drying step, in a semiconductor substrate having a fine concave-convex pattern, the concave-convex pattern is likely to deform or collapse. In order to dry a substrate on which a relief pattern has been formed using a sublimable substance, a process is generally carried out in which the liquid remaining in the relief 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, in a sublimation film forming composition containing a sublimation material and a solvent, by appropriately selecting a solvent having a relatively high dissolving power of the sublimation material and a relatively high volatility, or by appropriately combining two or more kinds of solvents, when the composition is used in a manufacturing process of a substrate having a concave-convex structure, the occurrence of pattern collapse in the concave-convex structure of the substrate can be suppressed.

[0018] As shown in the first embodiment, the solvent A1 may be adopted, which has a moderate dissolving power of sublimable material and a moderate volatility, or as shown in the second embodiment, the solvent A2 may be used in combination with the solvent B2, which has a moderate dissolving power of sublimable film and a moderate volatility.

[0019] Although the detailed mechanism is unclear, it is believed that the use of highly volatile solvents (solvent A1, solvent B2) that are more volatile than the sublimable substances enhances the film forming ability, while the use of highly soluble solvents (solvent A1, solvent A2) that have a relatively high dissolving power for the sublimable substances can suppress the premature and excessive precipitation of the sublimable substances, thereby suppressing pattern collapse caused by the premature precipitation of the sublimable substances.

[0020] In addition, 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 one type of pattern collapse is stripe collapse, which is different from planar collapse. The streak-like collapse basically refers to a state in which a pattern collapses continuously in a predetermined direction. The streak-like collapse may be formed so as to surround an area in which there is no predetermined pattern collapse. Even if the area collapse and the pattern collapse rate can be suppressed, the streak-like collapse may 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 the solvent A1 or solvent A2 having a higher dissolving power for the sublimable substance and / or by using the sublimable substance having a relatively low heat of solidification.

[0022] Although the detailed mechanism is unclear, it is believed that the streaky collapse occurs due to distortion at the crystal grain boundaries of the sublimable film. Therefore, it is believed 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 low heat of solidification to reduce crystallinity.

[0023] The sublimation film-forming composition of the present embodiment can be suitably used as a composition for drying a concave-convex pattern used in a step of drying a concave-convex structure in a manufacturing process of a substrate having a concave-convex structure. The sublimable material 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 the present embodiment will be described in detail below.

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

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

[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 atmospheric pressure. This makes it unnecessary to perform a treatment at an extremely low temperature for freezing the sublimable substance when applied to a method for manufacturing a substrate, thereby improving the manufacturing stability of the semiconductor substrate. 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 atmospheric pressure. This makes it unnecessary to perform a treatment at an extremely high temperature for the sublimation of the sublimable substance when applied to a method for manufacturing a substrate, thereby improving the manufacturing stability of the semiconductor substrate.

[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 solidification heat 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 suppress the occurrence of streaky collapse.

[0029] The sublimable material may be configured so as to be substantially free of non-volatile substances that become residues after sublimation. The 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 1% by mass or less, preferably 0.5% by mass or less, based on 100% by mass of the sublimable material, or unavoidable contamination may be 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, and 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 makes it easy to purify the sublimable substance. Also, in the normal temperature and normal pressure process, the sublimable substance is easily sublimated, improving the 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 a 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 the sublimable substance is the solidification start temperature determined by DSC under the condition 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 where 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 a typical room temperature in a clean room. In addition, when the sublimation temperature range is within the range of 20 to 25°C, sublimation promotion treatment such as heating or decompression is not required, 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, the symbol "to" indicates that the upper and lower limits are included, unless otherwise specified.

[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 with relatively small heat of solidification, non-halogen sublimable substances S2 with relatively large heat of solidification, sublimable substances S3 with 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 kinds.

[0034] The heat of solidification of the non-halogen sublimable material 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, the 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. In addition, when optical isomers exist, one or both may be used.

[0036] The lower limit of the content of the sublimable substance in the sublimable film-forming composition is, for example, 0.1 mass% or more, preferably 0.5 mass% or more, more preferably 0.8 mass% or more. This tends to make it easier to solidify the sublimable substance uniformly in the sublimable film-forming composition. On the other hand, the upper limit of the content of the sublimable substance in the sublimable 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 is easy to obtain a cooling effect due to the heat of vaporization of the solvent, and tends to promote the solidification of the sublimable substance. In addition, it is preferable because it is easy to keep the time required for sublimation (sublimation time) short.

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

[0038] The saturation solubility is determined from the saturation concentration (mass %) of the sublimable substance dissolved in the solvent. When a mixture contains a plurality of solvents, the saturated solubility is a value defined for each solvent. When a sublimation film forming composition contains multiple 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 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 the 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 even 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] In addition, the sublimation film-forming composition may use a solvent A that is compatible with the remaining liquid remaining on the substrate surface. This makes it possible to efficiently replace the remaining liquid with the sublimation film-forming composition, and to stably perform the drying process of the remaining liquid. The remaining liquid may be a typical solvent used in a semiconductor cleaning process, specifically, water, alcohol having 3 or less carbon atoms (eg, methanol, 1-propanol, 2-propanol, etc.), or a mixture thereof. Being compatible means that the dissolution amount of the solvent used in the cleaning step per 1 part by mass of solvent A at 25° C. and 1 atmospheric pressure is, for example, 0.05 part by mass or more.

[0041] The sublimable film forming composition of the first embodiment contains one or more solvents A1 in which the saturation 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 atmospheric pressure. 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 atmospheric pressure-boiling point of the 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 the present 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 defined 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 suppresses the excessive premature precipitation of the sublimation material, and the solvent A1 with higher volatility than the sublimation material can promote the formation of the sublimation film (solidification of the sublimation material) by the heat of vaporization. This can reduce the pattern collapse rate after the sublimation film is formed and removed, and also suppress streaky collapse.

[0045] The sublimable film forming composition of the present embodiment may contain one or more solvents B whose boiling point is lower than the boiling point of the sublimable substance at 1 atmospheric pressure, in addition to the above-mentioned solvent A. Solvent B is defined to include the above-mentioned solvent B1 and solvent 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 the solvent A1. The solvent B1 is not particularly limited in terms of the saturation solubility of the sublimable substance, as long as it has a boiling point lower than that of the solvent A1 among the solvents B, but it can be used even if it is lower than the saturation solubility of the solvent A1. The difference between the boiling points of the solvents A1 and B1 is, for example, 5°C or more, preferably 10°C or more, more preferably 15°C or more, and may be 200°C or less, or 150°C or less. 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 mass % or more, preferably 0.8 mass % or more, and more preferably 0.9 mass % or more. In addition, in the case where the solvent A1 is the main component of the sublimation film-forming composition, the content of the 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 using another solvent, it is preferable to use the solvent B1 as the solvent. In that case, the content of the solvent A1 in the sublimation film-forming composition may be a value larger than that of the solvent B1. On the other hand, the upper limit of the content of solvent A1 may be, for example, 99.9% by mass or less, preferably 99.5% by mass or less, more preferably 99.2% by 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% by mass, preferably 30% by mass or less, more preferably 15% by mass or less.

[0048] The sublimable film forming composition of the second embodiment includes one or more solvents A2 having a saturation solubility of a sublimable substance exceeding 10 mass %, and one or more solvents B2 having a content in the sublimable film forming composition greater than that of the solvent A2 and a boiling point less than that of the sublimable substance at 1 atmospheric pressure and less than that of the solvent A2.

[0049] Solvent A2 is selected from the above-mentioned solvents A. (Boiling point of sublimable substance at 1 atmospheric pressure-boiling point of solvent A2) may be 0°C, or may be 0°C or more and less than 5°C, or may be 5°C or more and 200°C or less. From the viewpoint of facilitating solidification of the sublimable substance, for example, 0°C or more and 200°C or less may be preferable, and 5°C or more and 200°C or less 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 saturation solubility of the sublimable substance is not particularly limited, and even if it is lower than the saturation solubility of the sublimable substance in solvent A2, it can be used. However, the content of the solvent B2 in the sublimation film-forming composition is greater than the content of the solvent A2. Preferably, the solvent B2 may be included as a main component in the sublimation film-forming composition. The main component means that the lower limit of the content of the 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 the 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 the solvent B2 as a main component, the content of the solvent A2 is, for example, 0.1% by mass to 30% by mass, and preferably 0.5% by mass to 10% by mass.

[0051] In the sublimation film forming composition of the second embodiment, by containing at least one each of such solvent A2 and solvent B2, solvent B2 volatilizes relatively 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 considered that it is possible to suppress the excessive premature 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 be suppressed. In addition, 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 film formation time of 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, and is, for example, 5°C or higher, preferably 10°C or higher, more preferably 15°C or higher, and even more preferably more than 20°C, while it may 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 included, as an example, the second or subsequent solvents A1 may be selected from those having a saturated solubility of the sublimable substance in the solvent A1 of 40% by mass or more and a boiling point of 200° C. or less, and preferably may be selected from those having a saturated solubility of the sublimable substance in the solvent A1 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 included, as an example, the second or subsequent solvent A2 may be selected from those having a saturation solubility of the sublimable substance in the solvent A2 of 40% by mass or more and a boiling point of the sublimable substance or less, preferably from those having a saturation solubility of the sublimable substance of 50% by mass or more and a boiling point of 210°C or less, more preferably from those having a saturation solubility of the sublimable substance of 60% by mass or more and a boiling point of 200°C or less, and even more preferably from those having a saturation solubility of the sublimable substance of 75% by mass or more and a boiling point of 180°C or less. In addition, when the solvent A2 contains two or more kinds and the solvent B2 contains one or more kinds, it is preferable that the boiling point difference between the solvents A2 is small because the solvent B2 is more likely to remain when it evaporates. The boiling point difference is not particularly limited as long as it can exert an effect as the solvent A2, but for example, the difference between the highest boiling point and the lowest boiling point 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 and 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 addition, the boiling point of the solvent B2 is smaller than the smallest boiling point of the solvent A2. The second or subsequent solvent B2 may be selected from those having a boiling point of, for example, 83° C. or lower, preferably 80° C. or lower, and more preferably 70° C. or lower.

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

[0057] Examples of the 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 the solvent A1, the solvent A2, the solvent B1, and the solvent B2, one or more kinds may be selected from the above-mentioned 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 alcohol having 3 or less carbon atoms, which is the residual liquid remaining on the substrate surface, it is preferable that the solvent A1 and the solvent A2 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 atoms or chlorine atoms in the molecule. Specific examples of these 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 alcohol having 3 or less carbon atoms, which is the remaining liquid remaining on the substrate surface, it is preferable that the solvents B1 and B2 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 for the purpose of adjusting wettability to the substrate and / or the uneven pattern, in addition to the above-mentioned solvents A1, A2, B1, and B2, within the range in which the effect of the present invention is not impaired, 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, nitrogen-containing compounds, and the like, and refer to solvents other than those 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), and the like. 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, and γ-butyrolactone. Examples of the ethers include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, Examples of the ketones include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, etc. Examples of the sulfoxide solvents include 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 the 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, and among these, solvents other than those of Solvents A1, A2, B1, and B2 are exemplified.

[0064] The lower limit of the total content of the solvent in the sublimable 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. 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 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. This tends to facilitate the solidification of the sublimation material uniformly on the substrate, which is preferable.

[0065] The sublimation film-forming composition is liquid, preferably a solution, at least when it is 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, such as 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 the liquid transfer mechanism or storage container, the compound is particularly preferably 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 relief structure 20 on its surface, supplying a sublimable film-forming composition 30 containing a sublimable substance onto the surface (FIG. 1(a)), solidifying the sublimable film-forming composition 30 to form a sublimable film 50 on the surface (FIG. 1(b)), and sublimating the sublimable substance to remove the sublimable film 50 (FIG. 1(c)).

[0067] As the sublimation film forming composition 30 containing a sublimation material 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 suppress pattern collapse of the concave-convex structure 20 formed on the substrate 10.

[0068] The method for manufacturing the substrate will now be described in detail. In the above-mentioned 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, and the exposed or unexposed resist is removed to produce a resist having a desired concave-convex pattern. Alternatively, a resist having a concave-convex pattern can be obtained by pressing a mold having 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) having a concave-convex structure 20 on its surface.

[0069] There are no particular limitations on the wafer on which the uneven structure 20 is formed and the material of the uneven 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. As for the material of the uneven structure 20, silicon-based materials such as silicon oxide, silicon nitride, polycrystalline silicon, and single crystal silicon, metal-based materials such as titanium nitride, tungsten, ruthenium, tantalum nitride, and tin, and materials combining these, resist (photoresist) materials, etc. can be used.

[0070] 1(a) is a cross-sectional view showing an example of a concave-convex pattern 20. In the cross-sectional structure (in the thickness direction of the substrate) of the concave-convex pattern 20, at least one of the pattern dimensions of the width and height, or in the three-dimensional structure (three-dimensional coordinates of XYZ) of the concave-convex pattern 20, at least one of the pattern dimensions of the width (length in the X-axis direction), the height (length in the Y-axis direction), and the 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 drying composition of this embodiment can be used to reduce the pattern collapse rate. In the cross-sectional view of Fig. 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 be suitably used even when the inclination of the concave-convex pattern 20 is not parallel to the thickness direction of the substrate. The above "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, not less than 3, not less than 5, or not less than 10. Even in the concave-convex structure 20 having the protrusions 22 with a fragile structure, pattern collapse can be suppressed. 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 protrusion 22 is expressed by the value obtained by dividing the height of the protrusion 22 by the width of the protrusion 22 .

[0073] After the unevenness structure 20 is formed, 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 process, as shown in FIG. 1(a), a liquid sublimation film forming composition is supplied to the uneven 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 a part or all of the recesses 24 of the uneven structure 20 (sometimes referred to as a "sublimation film forming composition supplying process", or simply a "filling process", or a "supplying process"). The supply may be performed, 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 sheet-type method, typically a spin type, in which the composition is supplied near the center of rotation while the wafers are held almost horizontally and rotated one by one, replacing the cleaning liquid, etc., held in the uneven pattern of the wafer, and the composition is filled in, or a batch type, in which multiple wafers are immersed in a composition tank, replacing the cleaning liquid, etc., held in the uneven pattern of the wafer, and the composition is filled in, may be used.

[0076] The cleaning liquid used remains on the surface of the substrate 10 after the cleaning process. 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 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 (sometimes referred to as "a step of forming a sublimable film" or simply as "solidification step"). The sublimable film 50 filled inside the recesses 24 of the concave-convex structure 20 can suppress the pattern collapse of the concave-convex structure 20.

[0079] In the solidification step, the solid sublimable substance may be precipitated by cooling, or the solvent may be evaporated by applying heating or appropriate environmental conditions, and the solid sublimable substance may be precipitated by the heat of vaporization. In this embodiment, as described above, by appropriately selecting the solvents A1, A2, B1, and B2 used in the sublimation film-forming composition, it is possible to volatilize (dry) the solvents, for example, at room temperature and pressure (20°C to 25°C, 1 atm). Furthermore, by setting the lower limit of the freezing point of the sublimable substance to be equal to or higher than the above lower limit, extreme cooling becomes unnecessary, and it becomes possible to solidify the sublimable substance by the heat of vaporization of the solvent. When the solidification step is carried out at room temperature and pressure, the evaporation of the solvent may be promoted as necessary, for example, by rotating the substrate 10 or by spraying 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 a "process for removing the sublimable film" or simply a "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 performed at room temperature and pressure, but if necessary, heating or decompression may be performed.

[0081] The manufacturing method shown in Fig. 1 is for a wafer pattern, but the present invention is not limited thereto. The manufacturing method of the substrate of the present embodiment is for a resist pattern, and it is also possible to suppress the collapse of the resist pattern by using the sublimation film-forming composition of the present invention in the cleaning and drying process. The supplying step described above is performed after the cleaning step in the manufacturing method, but is not limited thereto, and may be performed after various treatments performed on the concave-convex structure 20. For example, the supplying step may be performed after the concave-convex structure 20 is treated with a chemical solution for forming a water-repellent protective film. In addition to the above-mentioned steps, the method for manufacturing the substrate may 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-mentioned removing step.

[0082] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope 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," unless otherwise specified, are used merely to distinguish configurations with similar names, and do not imply any particular characteristic (e.g., order or importance) of the configurations. EXAMPLES

[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 Sublimable 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 saturation solubility (mass%) of the sublimation agent in the solvent.

[0085] The saturation solubility means the saturation 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 the solvent in a mass ratio of about 3:1, heating it to 40°C, and cooling it to room temperature (about 25°C). When the mixture became a coexistence of solid and liquid at room temperature, 10 μL of the liquid portion was collected with a microsyringe, diluted 100 times (volume ratio) with a dilution solvent, analyzed by gas chromatography, and converted to a mass ratio to obtain the saturated solubility (mass%). When no precipitation of the sublimation agent occurred at room temperature and a homogeneous solution was obtained, the amount of the sublimation agent relative to the solvent was increased and the same procedure was carried out. Also, when the liquid portion was small at room temperature and it was difficult to collect it with a microsyringe, the amount of the solvent relative to the sublimation agent was increased and the same procedure was carried out. The mass ratio based on gas chromatography was calculated by attaching a capillary column (Model TC-1, GL Sciences, length 30 m, liquid phase thickness 5 μm, inner diameter 0.32 mm) 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 from those that provide peaks that are sufficiently separated from the sublimation agent and the solvent to be measured by gas chromatography, and specifically, those that are 0.1 minutes or more apart in the development time on the chromatogram were 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 saturation 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 obtain 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 saturation 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 structure with multiple roughly cylindrical protrusions, each 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 protrusions and the distance between adjacent protrusions), 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. Next, the evaluation substrate was placed on a spin coater, and 2-propanol was supplied to hold the liquid (2-propanol) in the concaves of the concave-convex structure. Next, 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)). Next, the evaluation substrate was rotated at 100 revolutions per minute using a spin coater, and the formation of a sublimable film (a solidified film of a sublimable substance) was visually confirmed (step (II)). Next, rotation was continued until disappearance of the sublimable film was confirmed by visual observation (step (III)). The above steps (I) to (III) were carried out at 23 to 24° C. under a nitrogen atmosphere at 1 atm. 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 calculated 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 parts were included in the field of view, counting the number of convex parts that had collapsed in the obtained image, and calculating the ratio of these to the number of convex parts in the field of view as a percentage. The values ​​were rounded off to the nearest 10 according to 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, and streak collapse occurred to some extent, and Examples 21 and 22 showed little streak collapse.

[0090] In addition, the boiling point of isoborneol is the sublimation point in Table 3. 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 a suppressed result of streaky collapse. Such sublimation film forming compositions of Examples 1 to 75 can be suitably used in the manufacturing process of a substrate having a concave-convex structure, and can improve the manufacturing stability of the substrate.

[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 24 Recess 30 Sublimable film forming composition 50 Sublimable membrane

Claims

1. A sublimation film-forming composition comprising a sublimable material, A solvent A2 having a saturation 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, the sublimable substance is at least one selected from the group consisting of norbornene, norbornane, camphor, pyrazine, 2,3-dichloropyrazine, 2,6-dichloropyrazine, 2,6-dichloropyridine, tetrahydrodicyclopentadiene, dimethyl oxalate, isoborneol, neopentyl alcohol, neopentyl glycol, and ethylene carbonate; The solvent A2 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; The solvent B2 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. Sublimable film-forming composition.

2. The sublimable film-forming composition according to claim 1, The content of the solvent B2 in the sublimation film forming composition is 50 mass % or more.

3. The sublimation film-forming composition according to claim 1 or 2, A sublimation film forming composition, wherein the difference between the boiling point of the solvent A2 and the boiling point of the solvent B2 is 5° C. or more.

4. The sublimation film forming composition according to any one of claims 1 to 3, A sublimable film-forming composition, wherein the heat of solidification of the sublimable substance is 200 J / g or less.

5. The sublimation film forming composition according to any one of claims 1 to 4, The sublimable film-forming composition, wherein the freezing point of the sublimable substance at 1 atmospheric pressure is 5° C. or higher.

6. The sublimation film forming composition according to any one of claims 1 to 5, A sublimable film-forming composition, comprising a sublimable substance having a boiling point of 300° C. or less at 1 atmospheric pressure.

7. The sublimation film forming composition according to any one of claims 1 to 6, A sublimation film-forming composition, wherein the content of the sublimation substance in the sublimation film-forming composition is 80 mass % or less.

8. The sublimation film forming composition according to any one of claims 1 to 7, A sublimation film-forming composition used to suppress pattern collapse of an uneven structure formed on a substrate.

9. The sublimable film-forming composition according to claim 8, A sublimation film-forming composition for use in treating a substrate having a relief structure with a pattern dimension of 30 nm or less.

10. The sublimable film-forming composition according to claim 9, The sublimation film-forming composition is used for treating the substrate having a relief structure with a pattern dimension of 20 nm or less.

11. A step of preparing a substrate having a relief structure on a surface thereof; supplying a sublimable film-forming composition containing a sublimable material onto the surface; solidifying the sublimation film forming composition to form a sublimation film on the surface; sublimating the sublimable material 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 7. A method for manufacturing a substrate.

12. A method for manufacturing a substrate according to claim 11, comprising the steps of: 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.

13. A method for manufacturing a substrate according to claim 12, comprising the steps of: 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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