Pellicle film and pellicle

Abstract

The purpose of the present invention is to provide a novel pellicle film which exhibits excellent transmittance of light having a wavelength suitable for photolithography and which is capable of ensuring mechanical strength and / or light resistance.　Provided is a pellicle film (3) containing a polysiloxane having a cage-type silsesquioxane structure, wherein the wavelength suitable for photolithography is, for example, 190-440 nm.

Description

Pellicle membrane and pellicle

[0001] The present invention relates to a pellicle membrane and a pellicle.

[0002] A dust-proofing means called a pellicle is commonly used in the pattern formation process for electronic devices, etc. A pellicle is made by spreading a transparent thin polymer film (hereinafter referred to as "pellicle film") and bonding it to a frame, and has the function of preventing foreign matter from adhering to photomasks, reticles, etc.

[0003] Regarding pellicle membrane materials, Patent Document 1 describes a pellicle material made of a polyladder siloxane having repeating units represented by a specific general formula in the molecule. Patent Document 1 reports that by using such a pellicle material to form a pellicle membrane, it is possible to suppress deterioration of the pellicle material when exposed to laser light using short wavelength light.

[0004] For example, Patent Document 2 describes a pellicle film for ultraviolet light with a wavelength of 140 to 200 nm, which is made of an organic polymer that satisfies a specific relationship between the film thickness when made into a film and the average light absorptance in the wavelength region of the exposure light source of the film. Patent Document 2 reports that such a pellicle film can suppress deterioration of the pellicle material when exposed to laser light using short wavelength light (e.g., KrF excimer laser and ArF excimer laser).

[0005] Japanese Patent Application Laid-Open No. 4-166840 International Publication No. 98 / 36324

[0006] However, coupled with the recent trend toward finer patterns in electronic devices and the like, conventional pellicle films using pellicle materials such as those described in Patent Documents 1 and 2 have room for improvement in terms of exhibiting excellent transmittance to light having wavelengths suitable for photolithography.

[0007] Furthermore, as pellicle membranes become thinner and thinner, a solution has been awaited to the problem of how to ensure the mechanical strength and / or light resistance (durability against light) of pellicle membranes.

[0008] An object of the present invention is to provide a novel pellicle membrane that exhibits excellent transmittance to light having a wavelength suitable for photolithography and that can ensure mechanical strength and / or light resistance, and also to provide a pellicle using such a pellicle membrane.

[0009] One aspect of the present invention is as follows: [1] A pellicle film comprising a polysiloxane having a cage silsesquioxane structure. [2] The polysiloxane is represented by the following formula (i): {In formula (i), R １１ , and R １２ each independently represents a siloxy group (—OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F) that constitutes the polysiloxane. １１ , and a total of four R １２ at least two of which represent siloxy groups (—OSi) that constitute the polysiloxane; a structure represented by the following formula (ii): {In formula (ii), R ２１ , and R ２２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F); R ２３ , and R ２４ each independently represents a siloxy group (—OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F) that constitutes the polysiloxane. ２３ , and a total of two R ２４ at least two of which are siloxy groups (—OSi) that constitute the polysiloxane.}, and a structure represented by the following formula (iii): {In formula (iii), R ３１ , and R ３２ each independently represents a siloxy group (—OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F) that constitutes the polysiloxane.３１ , and a total of five Rs ３２

[0023] Item 1: The pellicle membrane according to item 1, wherein the polysiloxane has at least one structure selected from the group consisting of a structure represented by the following formula (I-1): {In formula (I-1), R １１ , R １２ , and R ４１ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH) or a fluoro group (—F), and n represents an integer of 1 to 30.}, a structure represented by the following formula (II-1): {In formula (II-1), R ２１ , R ２２ , R ２３ , and R ４１ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F), and n represents an integer of 1 to 30.}, and a structure represented by the following formula (III-1): {In formula (III-1), R ３１ , R ３２ , and R ４１ each independently represent a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F), and n represents an integer of 1 to 30.} and at least one structure selected from the group consisting of: [4] The pellicle membrane according to item 3, wherein in the polysiloxane, the proportion of structural units derived from structures represented by formulas (i) to (iii) is 50 mass% or more, and / or the proportion of structures represented by formulas (I-1) to (III-1) is 50 mass% or more. [5] A pellicle comprising a frame and a pellicle membrane attached to the frame, wherein the pellicle membrane is the pellicle membrane according to any one of items 1 to 4. [6] A preparation liquid for producing a pellicle membrane, comprising a polysiloxane having a cage silsesquioxane structure.

[0010] According to the present invention, it is possible to provide a novel pellicle membrane that exhibits excellent transmittance to light having a wavelength suitable for photolithography and that can ensure mechanical strength and / or light resistance. Furthermore, according to the present invention, it is possible to provide a pellicle using such a pellicle membrane.

[0011] FIG. 2 is a diagram showing an example of the configuration of a pellicle according to the present embodiment.

[0012] An embodiment of the present invention (hereinafter also referred to as "the present embodiment") will be described below. The present invention is not limited to the present embodiment, and various modifications can be made within the scope of the gist thereof.

[0013] In the present specification, when a plurality of structures represented by the same symbol exist in the same formula, the structures may be independently selected and may be the same or different from each other, unless otherwise specified. When a plurality of structures represented by the same symbol exist in different formulas, the structures may be independently selected and may be the same or different from each other, unless otherwise specified. In the chemical formulas, the abbreviation "Me" represents a methyl group (-CH ３ ), and the abbreviation "Ph" stands for phenyl group (-C ６ H ５ ) respectively.

[0014] Furthermore, in this specification, the upper or lower limit value of a numerical range described in stages may be replaced with the corresponding upper or lower limit value of another numerical range described in stages, and may also be replaced with the corresponding value described in the examples.

[0015] Furthermore, in this specification, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps, as long as the function of the step is achieved. In the contents shown in the drawings, the scale, shape, and length may be exaggerated for clarity.

[0016] [Embodiment 1] <Pellicle Film> The pellicle film of the present disclosure (hereinafter, sometimes referred to as the "present pellicle film") comprises a polysiloxane having a cage silsesquioxane structure (hereinafter, sometimes referred to as the "present polysiloxane"). The present inventors conducted extensive research in search of a novel pellicle film that can be used in photolithography using j-line, i-line, h-line, g-line, and the like, and as a result, discovered that by using the present polysiloxane as a material, a pellicle film that exhibits excellent transmittance to light having wavelengths suitable for photolithography can be realized. The pellicle film of the present disclosure exhibits excellent transmittance to light having wavelengths suitable for photolithography, for example, light with a wavelength of 190 nm to 440 nm, particularly light with a wavelength of 290 nm to 440 nm, and light with wavelengths of 193 nm and 248 nm, and can therefore meet the demands of next-generation electronic devices, for example, the demand for further miniaturization of patterns.

[0017] Furthermore, the present pellicle membrane not only has excellent transparency, but also has excellent mechanical strength such as puncture resistance, and / or light resistance (durability to light, for example, durability to light with wavelengths of 190 nm to 440 nm, particularly durability to light with wavelengths of 290 nm to 440 nm, and durability to light with wavelengths of 193 nm and 248 nm). Thus, the present disclosure can provide a pellicle membrane that is highly practical in terms of transparency, mechanical strength, and / or light resistance.

[0018] <Polysiloxane Having a Cage-Type Silsesquioxane Structure> The present polysiloxane has a cage-type silsesquioxane structure. Here, the term "silsesquioxane" refers to, for example, a unit formed by condensing a trifunctional silane, such as the following T unit: (In the above units, R is an optional substituent.) In particular, the term "cage-type silsesquioxane" refers to a polysiloxane consisting only of the above T units {composition formula: (RSiO １．５ ) ｍ, 5≦m≦100} and forming a polyhedral structure. Furthermore, "polysiloxane having a cage silsesquioxane structure" means that a "cage silsesquioxane" structure is introduced into the siloxane skeleton (Si—O—Si…) of the polysiloxane. Note that "cage silsesquioxane" in the present disclosure encompasses both the concepts of a "complete cage silsesquioxane" in which the cage is closed, and an "incomplete cage silsesquioxane" in which part of the cage is open.

[0019] In the cage-type silsesquioxane, the composition formula (RSiO １．５ ) ｍ In the formula, m is preferably 6 or more, more preferably 7 or more, even more preferably 8 or more, and is preferably 50 or less, more preferably 20 or less, even more preferably 12 or less. When m in the composition formula is within the above range, it is easier to ensure the light transmittance, mechanical strength, light resistance, etc. of the pellicle film. Note that m may be an integer.

[0020] The polysiloxane has the following formula (i): {In formula (i), R １１ , and R １２ each independently represents a siloxy group (—OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F) that constitutes the polysiloxane. １１ , and a total of four R １２ at least two of which represent siloxy groups (—OSi) that constitute the polysiloxane; a structure represented by the following formula (ii): {In formula (ii), R ２１ , and R ２２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F); R ２３ , and R ２４each independently represents a siloxy group (—OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F) that constitutes the polysiloxane. ２３ , and a total of two R ２４ at least two of which are siloxy groups (—OSi) that constitute the polysiloxane.}, and a structure represented by the following formula (iii): {In formula (iii), R ３１ , and R ３２ each independently represents a siloxy group (—OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F) that constitutes a polysiloxane. ３１ , and a total of five Rs ３２ at least two of which are siloxy groups (—OSi) constituting the polysiloxane.} The presence of these structures makes it easier to further ensure the light transmittance, mechanical strength, light resistance, and the like of the pellicle film.

[0021] The polysiloxane may have a plurality of mutually different structures represented by the formula (i) above, may have a plurality of mutually different structures represented by the formula (ii) above, may have a plurality of mutually different structures represented by the formula (iii) above, may have a structure represented by the formula (i) above and a structure represented by the formula (ii) above, may have a structure represented by the formula (i) above and a structure represented by the formula (iii) above, may have a structure represented by the formula (ii) above and a structure represented by the formula (iii) above, may have a structure represented by the formula (i) above and a structure represented by the formula (ii) above, may have a structure represented by the formula (i) above and a structure represented by the formula (ii) above, or may have all of the structures represented by the formulas (i) to (iii) above.

[0022] In the above formulas (i) to (iii), R １１ , R １２ , R ２１ , R ２２ , R ３１ , and R ３２can be easily realized by synthesizing polysiloxane using raw materials containing these groups, or by introducing these groups during the synthesis of polysiloxane. Also, R can be obtained by subjecting the hydrocarbon group to heat treatment such as flash annealing, or by removing the hydrocarbon group by UV irradiation, ozone treatment, etc. １１ , R １２ , R ２１ , R ２２ , R ３１ , and R ３２ is easily introduced as a substituent. １１ , R １２ , R ２１ , R ２２ , R ３１ , and R ３２ These can be easily realized by appropriate methods depending on the type of the object.

[0023] In the above formulas (i) to (iii), R １１ , R １２ , R ２１ , R ２２ , R ３１ , and R ３２ It is preferable that at least one of a hydrogen atom (-H), a hydroxy group (-OH), and a fluoro group (-F) is selected as R , and in this case, it is easy to realize a pellicle membrane that is excellent in transmittance of light having a short wavelength. １１ , and R １２ the ratio of hydrogen atoms (—H), hydroxy groups (—OH), and fluoro groups (—F) in the formula (ii), ２１ , and R ２２ the ratio of hydrogen atoms (—H), hydroxy groups (—OH), and fluoro groups (—F) in the formula (iii), and ３１ , and R ３２The proportion of hydrogen atoms (-H), hydroxy groups (-OH), and fluoro groups (-F) in the above is preferably high, and it is preferred that 10% or more, preferably 20% or more, more preferably 30% or more, and even more preferably 40% or more of these substituents are at least one selected from the group consisting of hydrogen atoms (-H), hydroxy groups (-OH), and fluoro groups (-F). This proportion may be 100% or less, 90% or less, 80% or less, or 70% or less.

[0024] The weight-average molecular weight of the polysiloxane may be 2,000 or more and 10,000,000 or less, preferably 5,000 or more, more preferably 7,000 or more, and preferably 2,000,000 or less, more preferably 1,000,000 or less. When the weight-average molecular weight is within the above range, it is easier to ensure the light transmittance, mechanical strength, light resistance, etc. of the pellicle membrane. The weight-average molecular weight may be measured based on a chromatogram measured by gel permeation chromatography (GPC).

[0025] (Structure represented by formula (i)) In the above formula (i), "a total of four R １１ , and a total of four R １２ At least two of the groups R represent siloxy groups (—OSi) constituting the polysiloxane. １１ , and R １２ This means that at least two of the eight R's in total, obtained by adding up the above, are bonded to siloxy groups (—OSi) that constitute the polysiloxane, that is, they connect repeating units together.

[0026] Furthermore, the "hydrocarbon group" in the above formula (i) may be a hydrocarbon group having any of a linear structure, a branched structure, and / or a cyclic structure, and may also be a hydrocarbon group having a carbon-carbon unsaturated bond (for example, a carbon-carbon double bond structure or a carbon-carbon triple bond structure) or a hydrocarbon group having no carbon-carbon unsaturated bond. When the "hydrocarbon group" has a cyclic structure, such a ring may be an alicyclic ring or an aromatic ring. Therefore, both aliphatic hydrocarbon groups and aromatic hydrocarbon groups having one cyclic structure (i.e., monocyclic) and aliphatic hydrocarbon groups and aromatic hydrocarbon groups having multiple cyclic structures (i.e., polycyclic) are included in the concept of the "hydrocarbon group." Naturally, groups referred to as alkyl groups, alkenyl groups, alkynyl groups, aryl groups, etc. are included in the concept of the "hydrocarbon group."

[0027] R １１ , and / or R １２ When is a hydrocarbon group, the number of carbon atoms therein is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. The number of carbon atoms therein may be 1 or more.

[0028] R １１ , and / or R １２ is a hydrocarbon group, the hydrocarbon group may be a methyl group (—CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (—CH ２ CH ２ CH ３ ), i-propyl group (—CH(CH ３ ) ２ ), n-butyl group (—CH ２ CH ２ CH ２ CH ３ ), s-butyl group (—CH ２ CH (CH ３ ) ２ ), t-butyl group (—C(CH ３ ) ２ ), a cyclohexyl group (-C ６ H １１ ), a phenyl group (-C６ H ５ ), etc.

[0029] (Structure represented by formula (ii)) In the above formula (ii), ２１ , and a total of two R ２２ At least two of the groups represented by R represent siloxy groups (—OSi) constituting the polysiloxane. ２１ , and R ２２ This means that at least two of the four R's in total, obtained by adding up the above, are bonded to siloxy groups (—OSi) that constitute the polysiloxane, that is, they connect repeating units together.

[0030] For the "hydrocarbon group" in the above formula (ii), the details explained in the above formula (i) may be referred to. ２１ , and / or R ２２ When is a hydrocarbon group, the number of carbon atoms therein is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. The number of carbon atoms therein may be 1 or more.

[0031] R ２１ , and / or R ２２ is a hydrocarbon group, the hydrocarbon group may be a methyl group (—CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (—CH ２ CH ２ CH ３ ), i-propyl group (—CH(CH ３ ) ２ ), n-butyl group (—CH ２ CH ２ CH ２ CH ３ ), s-butyl group (—CH ２ CH (CH ３ ) ２ ), t-butyl group (—C(CH ３ ) ２ ), a cyclohexyl group (-C ６ H １１ ), a phenyl group (-C ６ H ５), etc.

[0032] (Structure represented by formula (iii)) In the above formula (iii), ３１ , and a total of five Rs ３２ At least two of the groups represented by R represent siloxy groups (—OSi) constituting the polysiloxane. ３１ , and R ３２ This means that at least two of the ten R's, calculated by adding up the above, are bonded to siloxy groups (—OSi) that constitute the polysiloxane, i.e., they connect repeating units together.

[0033] In the above formula (iii), the "hydrocarbon group" may refer to the description of the above formula (i). ３１ , and / or R ３２ When is a hydrocarbon group, the number of carbon atoms therein is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. The number of carbon atoms therein may be 1 or more.

[0034] R ３１ , and / or R ３２ is a hydrocarbon group, the hydrocarbon group may be a methyl group (—CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (—CH ２ CH ２ CH ３ ), i-propyl group (—CH(CH ３ ) ２ ), n-butyl group (—CH ２ CH ２ CH ２ CH ３ ), s-butyl group (—CH ２ CH (CH ３ ) ２ ), t-butyl group (—C(CH ３ ) ２ ), a cyclohexyl group (-C ６ H １１ ), a phenyl group (-C ６ H ５ ), etc.

[0035] As the cage silsesquioxane structure, the structure represented by the above formula (i) includes the following formula: Examples of the structure represented by formula (ii) include a structure represented by the following formula: Examples of the structure represented by formula (iii) include a structure represented by the following formula: The structure may be represented by at least one of the following:

[0036] <<Monomer>> The present polysiloxane can be formed by using a cage silsesquioxane as a monomer and condensing this with a silanol group (Si—OH) of a siloxane or the like.

[0037] (Monomer for forming the structure represented by formula (i)) The monomer for forming the structure represented by formula (i) is, for example, a monomer represented by the following formula: This synthetic route shows an example of the synthesis of a cage silsesquioxane having two different types of substituents facing each other (for example, a "Cl group" and a "Me group" facing each other from above and below the page). A cage silsesquioxane having two different types of substituents facing each other is particularly called a "Janus cube."

[0038] According to the above synthesis route, a hydrolyzable functional group such as Si—Cl can be introduced, and the resulting cage silsesquioxane can be easily used as a monomer for the present polysiloxane. Regarding the preparation of the monomer for forming the structure represented by formula (i), reference may be made to WO 2017 / 065311 and WO 2018 / 101213.

[0039] The monomers for forming the structure represented by formula (i) include those represented by the following formulae (mi-1) to (mi-3): {In formulas (mi-1) to (mi-3), R １１ , and R １２each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F), and each X independently represents a halogen atom, a hydrogen atom (—H), or an alkoxy group having 1 to 8 carbon atoms.

[0040] In the above formulas (mi-1) to (mi-3), the "hydrocarbon group" has the same meaning as the "hydrocarbon group" explained in the above formula (i). That is, the number of carbon atoms in the hydrocarbon group is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. In addition, examples of the hydrocarbon group include a methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (—CH ２ CH ２ CH ３ ), i-propyl group (—CH(CH ３ ) ２ ), n-butyl group (—CH ２ CH ２ CH ２ CH ３ ), s-butyl group (—CH ２ CH (CH ３ ) ２ ), t-butyl group (—C(CH ３ ) ２ ), a cyclohexyl group (-C ６ H １１ ), a phenyl group (-C ６ H ５ ) etc.

[0041] In the above formulas (mi-1) to (mi-3), an example of the "halogen atom" is a chlorine atom (chloro group), and an example of the "alkoxy group" is a methoxy group (-OCH ３ ), etc.

[0042] (Monomer for forming the structure represented by formula (ii)) The monomer for forming the structure represented by formula (ii) is, for example, a monomer represented by the following formula: It can be prepared by a synthetic route represented by the following formula. For the preparation of the monomer for forming the structure represented by formula (ii), reference may be made to JP-A-2011-190413, JP-A-2015-155541, JP-A-2017-14320, and JP-A-2021-178892.

[0043] The monomer for forming the structure represented by formula (ii) includes the following formula (mii-1): {In formula (mii-1), R ２１ , and R ２２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F), and each X independently represents a halogen atom, a hydrogen atom (—H), or an alkoxy group having 1 to 8 carbon atoms.

[0044] In the above formula (mii-1), the "hydrocarbon group" has the same meaning as the "hydrocarbon group" explained in the above formula (i). An example of the "halogen atom" is a chlorine atom (chloro group), and an example of the "alkoxy group" is a methoxy group (-OCH ３ ), etc.

[0045] (Monomer for forming the structure represented by formula (iii)) The monomer for forming the structure represented by formula (iii) is represented by the following formulae (miii-1) to (miii-3): {In formulas (miii-1) to (miii-3), R ３１ , and R ３２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F), and each X independently represents a halogen atom, a hydrogen atom (—H), or an alkoxy group having 1 to 8 carbon atoms.

[0046] In the above formula (miii-1), the "hydrocarbon group" has the same meaning as the "hydrocarbon group" explained in the above formula (i). An example of the "halogen atom" is a chlorine atom (chloro group), and an example of the "alkoxy group" is a methoxy group (-OCH ３ ), etc.

[0047] (Copolymer) The present polysiloxane may be a polymer composed of a single monomer selected from the above-mentioned monomers, or a copolymer composed of multiple monomers including any of the above-mentioned monomers. When the present polysiloxane is a copolymer, the multiple monomers constituting the copolymer may consist solely of the above-mentioned monomers, or may contain monomers other than the above-mentioned monomers (hereinafter referred to as "other monomers"), provided that this does not contradict the spirit of the present invention. Examples of other monomers include those represented by the following formulae (miv-1) to (miv-2): {In formulas (miv-1) and (miv-2), R ４１ each independently represent a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxy group (-OH) or a fluoro group (-F); each X independently represent a halogen atom, a hydrogen atom (-H), a hydroxy group (-OH) or an alkoxy group having 1 to 8 carbon atoms; and m represents an integer of 2 to 10.} Compounds represented by formula (miv-1) are generally called silanes, and compounds represented by formula (miv-2) are generally called siloxanes.

[0048] In the above formulas (miv-1) and (miv-2), the "hydrocarbon group" has the same meaning as the "hydrocarbon group" explained in the above formula (i). That is, the number of carbon atoms in the hydrocarbon group is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. In addition, examples of the hydrocarbon group include a methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (—CH ２ CH ２ CH ３ ), i-propyl group (—CH(CH ３ )２ ), n-butyl group (—CH ２ CH ２ CH ２ CH ３ ), s-butyl group (—CH ２ CH (CH ３ ) ２ ), t-butyl group (—C(CH ３ ) ２ ), a cyclohexyl group (-C ６ H １１ ), a phenyl group (-C ６ H ５ ) etc.

[0049] In the above formulas (miv-1) and (miv-2), an example of the "halogen atom" is a chlorine atom (chloro group), and an example of the "alkoxy group" is a methoxy group (-OCH ３ ), etc.

[0050] When the present polysiloxane is a copolymer, the present polysiloxane may be any of an alternating copolymer, a random copolymer, and a block copolymer. Note that the "polysiloxane having at least one structure selected from the group consisting of structures represented by formulas (I-1) to (III-1)" described below may be treated as a block copolymer.

[0051] When the polysiloxane is a copolymer, the proportion of the substance amount of the cage silsesquioxane structure relative to the substance amount of all monomers (when the total substance amount of all monomers is taken as 100%) may be 1% or more and 90% or less, preferably 10% or more, more preferably 20% or more, even more preferably 30% or more, and is preferably 80% or less, more preferably 70% or less, even more preferably 60% or less, and particularly preferably 55% or less. When the proportion of the substance amount of the cage silsesquioxane structure is within the above range, it is easier to ensure the light transmittance, mechanical strength, light resistance, etc. of the pellicle film.

[0052] When the polysiloxane is a copolymer and contains other monomers, the proportion of the amount of substance of such other monomers relative to the amount of substance of all monomers (when the total amount of substance of all monomers is taken as 100%) may be 1% or more and 90% or less, preferably 10% or more, more preferably 20% or more, even more preferably 30% or more, and is preferably 80% or less, more preferably 70% or less, even more preferably 60% or less, and particularly preferably 55% or less. On the other hand, from the viewpoint of obtaining the effect of the monomers for forming the structures represented by formulas (i) to (iii), it is preferable that the amount of substance of the other monomers relative to the amount of substance of all monomers is smaller than the amount of substance of the monomers for forming the structures represented by formulas (i) to (iii).

[0053] Here, the present polysiloxane is represented by the following formula (I-1): {In formula (I-1), R １１ , R １２ , and R ４１ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH) or a fluoro group (—F), and n represents an integer of 1 to 30.}, a structure represented by the following formula (II-1): {In formula (II-1), R ２１ , R ２２ , R ２３ , and R ４１ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (—H), a hydroxy group (—OH), or a fluoro group (—F), and n represents an integer of 1 to 30.}, and a structure represented by the following formula (III-1): {In formula (III-1), R ３１ , R ３２ , and R ４１ are each independently a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxy group (-OH), or a fluoro group (-F), and n is an integer of 1 to 30.} and at least one structure selected from the group consisting of. By having these structures, it is easier to further ensure the light transmittance, mechanical strength, light resistance, etc. of the pellicle film.

[0054] In the present polysiloxane, the proportion of structural units derived from the structures represented by the above formulas (i) to (iii) is preferably 50% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 80% by mass or more. Furthermore, in the present polysiloxane, the proportion of structures represented by the above formulas (I-1) to (III-1) is preferably 50% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 80% by mass or more, and may even be 100% by mass. When these proportions are within the above ranges, it is easier to further ensure the light transmittance, mechanical strength, light resistance, and the like of the pellicle film.

[0055] <<Various Configurations>> The thickness of the pellicle film may be 0.10 μm or more and 10.0 μm or less, preferably 0.25 μm or more, more preferably 1.0 μm or more, and preferably 6.0 μm or less, more preferably 3.0 μm or less. When the thickness is within the above range, it is easier to ensure the light transmittance, mechanical strength, light resistance, etc. of the pellicle film.

[0056] The transmittance of the pellicle film for light having a wavelength of 190 nm or more and 290 nm or less is preferably 80% or more and 100% or less, more preferably 85% or more, and even more preferably 90% or more. The transmittance of the pellicle film for light having a wavelength of 290 nm or more and 385 nm or less is 80% or more and 100% or less, preferably 90% or more, and more preferably 95% or more. The transmittance can be measured based on the method described in the examples.

[0057] The transmittance of the pellicle film for light having a wavelength of 360 nm or more and 440 nm or less is 80% or more and 100% or less, preferably 90% or more, and more preferably 95% or more. The transmittance can be measured based on the method described in the Examples.

[0058] The present pellicle film may consist solely of a layer containing the present polysiloxane, or may include layers other than the layer containing the present polysiloxane (hereinafter referred to as "other layers"). Examples of other layers include layers with a lower refractive index than the film containing the present polysiloxane (e.g., an anti-reflection layer). The inclusion of an anti-reflection layer makes it easier to improve the light transmittance of the present pellicle film.

[0059] Examples of materials for the antireflection layer include fluorine-based polymers (tetrafluoroethylene-vinylidene fluoride-hexafluoropropylene ternary copolymers, polymers having a cyclic structure in the main chain such as Teflon AF (trade name) manufactured by DuPont, Cytop (trade name) manufactured by Asahi Glass Co., Ltd., Algoflon (trade name) manufactured by Ausimont, polyfluoroacrylate, etc.), calcium fluoride, magnesium fluoride, barium fluoride, etc.

[0060] The antireflection layer may be a polymer layer mainly containing a polymer or an inorganic layer mainly containing an inorganic material. When the antireflection layer is a polymer layer, the antireflection layer may be formed by spin coating, and when the antireflection layer is an inorganic layer, the antireflection layer may be formed by thin film formation methods such as vacuum deposition and sputtering.

[0061] The pellicle membrane may have a concave-convex structure on its surface. By having such a shape, the light transmittance of the pellicle membrane can be easily improved. As the concave-convex structure, the shape of the convex portions is preferably a polygonal pyramid shape, a cone shape, a truncated polygonal pyramid shape, or a truncated cone shape. A pellicle membrane having a concave-convex structure can be produced by forming the pellicle membrane on a substrate having a concave-convex structure, a film having a concave-convex structure, or the like.

[0062] <<Method for Producing Pellicle Film>> A known method and conditions for producing a pellicle film may be appropriately adopted as the method for producing the pellicle film. Examples include a method in which a solution capable of dissolving and / or dispersing the polysiloxane is formed on a substrate and then dried. Examples of film formation methods include spin coating, roll coating, knife coating, and casting, among which spin coating is preferred. Examples of drying methods include heating with a hot plate, clean oven, infrared rays, far infrared rays, etc.

[0063] Substrates used for film formation include synthetic quartz, fused quartz, alkali-free glass, low-alkali glass, soda-lime glass, and silicon wafers. The linear expansion coefficient of the substrate at temperatures between 0° C. and 300° C. is 50×10 －７It is preferable that the temperature is not higher than m / ° C. Furthermore, the surface of the substrate used in film formation may be subjected to a release treatment.

[0064] <Pellicle> The pellicle of the present disclosure (hereinafter sometimes abbreviated as "the present pellicle") comprises a frame body and a pellicle membrane attached to the frame body.

[0065] A preferred embodiment of the pellicle will be described below. Figures 1(a) and 1(b) are diagrams showing an example of the configuration of a pellicle 1 according to the present disclosure, with Figure 1(a) being a perspective view of the pellicle 1 and Figure 1(b) being a cross-sectional view taken along line A-A in Figure 1(a). In the diagram, the x, y, and z directions are shown orthogonal to one another, and these directions correspond to each other in Figures 1(a) and 1(b). Figure 1(b) also shows a photomask M to which the pellicle 1 is attached along the arrow directions.

[0066] As shown in the figure, pellicle 1 comprises a frame 2 and a pellicle film 3 attached to the frame 2. Pellicle 1 can be attached to photomask M so as to surround a circuit pattern (not shown) depicted on the photomask M, and therefore the size, shape, etc. of each component of pellicle 1 may be selected appropriately depending on the photomask M and the circuit pattern depicted on the photomask M. <Pellicle Film> Pellicle film 3 is stretched and attached to frame 2. Here, in pellicle 1, the pellicle film 3 described above is used. Therefore, the present disclosure provides a pellicle 1 that is highly practical in terms of the transparency of pellicle film 3, the mechanical strength of pellicle film 3, and / or the light resistance of pellicle film 3.

[0067] <<Frame body>> The frame body 2 has a pair of long sides 2 a and a pair of short sides 2 b. Therefore, when viewed in a plan view (projected view along the direction of arrow z), a rectangular opening Op is formed with these long sides 2 a and short sides 2 b as its edges.

[0068] In the case of a small pellicle, the length of the long side 2a may be 110 mm or more and 180 mm or less, and the length of the short side 2b may be 100 mm or more and 150 mm or less. In the case of a large pellicle, the length of the long side 2a may be 400 mm or more, 800 mm or more, or 2100 mm or more, and the length of the short side 2b may be 150 mm or more, 300 mm or more, or 400 mm or more.

[0069] The width of the long side 2a and the short side 2b may be 1.8 mm or more and 30 mm or less, preferably 1.8 mm or more, more preferably 2.0 mm or more, and even more preferably 4.0 mm or more, and is preferably 25 mm or less, more preferably 19 mm or less.

[0070] The thickness of each of the long side 2a and the short side 2b may be 3.0 mm or more and 10 mm or less, preferably 2.5 mm or more, more preferably 3.0 mm or more, and preferably 8.0 mm or less, more preferably 7.0 mm or less.

[0071] The cross-sectional shapes of the long sides 2 a and the short sides 2 b may be rectangular, H-shaped, T-shaped, etc. In this embodiment, the long sides 2 a and the short sides 2 b each have an approximately rectangular parallelepiped outer shape, and therefore the cross-sectional shapes of the long sides 2 a and the short sides 2 b are rectangular.

[0072] The frame 2 may be made of aluminum, aluminum alloys (5000 series, 6000 series, 7000 series, etc.); iron and iron-based alloys; ceramics (SiC, AlN, Al ２ O ３ etc.); ceramic and metal composite materials (Al-SiC, Al-AlN, Al-Al ２ O ３ carbon steel; tool steel; stainless steel series; magnesium alloy; resins such as polycarbonate resin and acrylic resin; etc.

[0073] The frame 2 preferably has ventilation holes 4 penetrating the inside and outside of the space formed between the pellicle 1 and the photomask M when the pellicle 1 is attached to the photomask M, for the purpose of reducing the difference in air pressure between the inside and outside of the space. The size and number of the ventilation holes 4 may be determined based on the volume of the space, etc. When the pellicle 1 has ventilation holes 4, the frame 2 preferably has a filter 5 such as a porous membrane that covers the ventilation holes 4, from the viewpoint of easily preventing foreign matter from entering the space.

[0074] The frame 2 preferably includes a film adhesive layer 6 for adhering the pellicle membrane 3. The film adhesive layer 6 can be disposed on one surface of the frame 2, particularly the surface on which the pellicle membrane 3 is adhered, and the provision of the film adhesive layer 6 makes it easier to support the pellicle membrane 3 in a stretched state. The film adhesive layer 6 can be formed by applying a film adhesive to the frame 2. In this case, examples of the film adhesive include epoxy-based, acrylic-based, silicone-based, and fluorine-based. The film adhesive can be cured as needed. In this case, examples of the adhesive curing method include thermal curing, photocuring, and anaerobic curing.

[0075] The frame 2 preferably includes a mask adhesive layer 7 for adhering to the photomask M. The mask adhesive layer 7 can be disposed on the other surface of the frame 2, particularly on the surface that is to be attached to the photomask M, and the provision of the mask adhesive layer 7 makes it easy to fix and remove the pellicle 1 to the photomask M. The mask adhesive layer 7 may be formed by applying a mask adhesive to the frame 2. In this case, examples of the type of mask adhesive include hot-melt adhesives (rubber-based and acrylic-based).

[0076] A tape-shaped adhesive member may be used as the mask adhesive layer 7. The tape-based adhesive member has, for example, an adhesive layer on both sides of a substrate. The substrate may be, for example, an acrylic or PVC sheet, or a rubber, polyolefin, or urethane foam, and the adhesive layer may be, for example, a layer containing a rubber, acrylic, or silicone adhesive.

[0077] <Prepared Solution for Producing Pellicle Film> Another aspect of the present invention is a prepared solution for producing a pellicle film, comprising a polysiloxane having a cage-type silsesquioxane structure. The polysiloxane having a cage-type silsesquioxane structure is as described above. The prepared solution may contain a solvent.

[0078] [Other Embodiments] This embodiment is not limited to the above-described aspects, and various modifications are possible within the scope of the gist. For example, the frame may have any outer and inner shape for attaching the pellicle film and for surrounding the circuit pattern depicted on the photomask. The frame may be configured to be separable. The pellicle may be fixed to the photomask by any jig, in which case the frame may have any shape corresponding to the jig. The pellicle film may be pressure-bonded to the frame, in which case the film adhesive layer may be omitted.

[0079] The present embodiment will be described below with reference to examples and comparative examples. However, the present embodiment is not limited to the following examples. In the examples and comparative examples, various productions, measurements, evaluations, etc. were carried out at room temperature (25°C) and atmospheric pressure unless otherwise specified.

[0080] [Prepared Solution for Producing Pellicle Film, and Pellicle Film] <Example 1> A solution containing a polysilsesquioxane having a cage silsesquioxane was prepared by the following production method. Note that for points not described below, reference may be made to the production methods described in JP 2015-155541 A and WO 2004 / 024741.

[0081] Phenyltrimethoxysilane (1 equivalent), 2-propyl alcohol, pure water (1.2 equivalents), and sodium hydroxide (0.5 equivalents) were added to a flask equipped with a reflux condenser and stirred under reflux for 5 hours. The mixture was then stirred at room temperature overnight. After stirring, pure water was added to the flask to stop the reaction. Next, a water washing operation was performed in which pure water was added, the mixture was stirred, and the aqueous layer was removed. After that, a white solid was separated from the liquid in the flask using a membrane filter with a pore size of 0.1 μm, and the white solid was obtained as a crude product.

[0082] Next, the crude product (1 equivalent), trichloromethylsilane (2 equivalents), and toluene (enough to dissolve the solute) were placed in a flask equipped with a dropping funnel and stirred, thereby obtaining a mixed solution. This mixed solution was mixed with triethylamine (4 equivalents) while stirring, and stirring was continued for 2 hours after mixing. After stirring, pure water was added to the flask to stop the reaction. Next, pure water was added, the mixture was stirred, and the aqueous layer was removed, performing a water washing operation several times. Thereafter, the solvent (toluene) was distilled off from the liquid in the flask using an evaporator to obtain a cage silsesquioxane. The synthetic reaction formula for the cage silsesquioxane is shown below: It is expressed as:

[0083] Next, tetrahydrofuran ((amount sufficient to dissolve the solute)), triethylamine (2 equivalents), and the above-mentioned cage silsesquioxane (1 equivalent) were placed in a flask equipped with a dropping funnel and stirred, thereby obtaining a mixed solution. The flask was cooled in an ice bath, and 1,7-dichlorooctamethyltetrasiloxane (1 equivalent) was added dropwise to the flask while stirring the mixed solution. Stirring was continued for 2 hours after the addition. Stirring was then continued overnight at room temperature. After stirring, pure water was added to the flask to stop the reaction. Next, a water-washing operation was performed several times, in which pure water was added, the mixture was stirred, and the aqueous layer was removed. Thereafter, the solvent (tetrahydrofuran) was removed from the liquid in the flask using an evaporator, and a solid was obtained.

[0084] The obtained solid was mixed with anisole so that the polymer concentration was 50% by mass, thereby obtaining a polymer having the following formula: A solution (polysiloxane solution) containing a polysiloxane having a cage silsesquioxane structure as a structural unit, represented by the formula: The weight average molecular weight of this polysiloxane solution measured by gel permeation chromatography (GPC) was 36,000.

[0085] The pellicle film was prepared as follows. The polysiloxane solution was spin-coated onto a quartz glass substrate at a rotation speed of 1500 rpm, thereby obtaining a thin film of polysiloxane on the substrate. The thin film on the substrate was dried on a hot plate at 80°C for 2 hours, thereby removing the solvent. The thin film was then peeled off from the substrate using tape peeling, obtaining a pellicle film of polysiloxane having a cage silsesquioxane structure. The film thickness of the obtained pellicle film was 6.0 μm. Furthermore, the obtained pellicle film could be stretched and adhered to a frame to prepare a pellicle.

[0086] Example 2 A polysiloxane solution containing a polysiloxane having a cage silsesquioxane structure (hereinafter referred to as the polysiloxane of Example 2) was prepared in the same manner as in Example 1, except that phenyltrimethoxysilane was changed to trimethoxymethylsilane. The polysiloxane of Example 2 had the following formula: The polysiloxane has a cage silsesquioxane structure as a structural unit, as represented by the formula (1). The weight-average molecular weight of this polysiloxane solution measured by gel permeation chromatography (GPC) was 35,000. A pellicle membrane was produced in the same manner as in Example 1. The membrane thickness of the obtained pellicle membrane was 6.0 μm. The obtained pellicle membrane was stretched and adhered to a frame to produce a pellicle.

[0087] Example 3 A polysiloxane solution containing a polysiloxane having a cage silsesquioxane structure (hereinafter, referred to as the polysiloxane of Example 3) was prepared in the same manner as in Example 1, except that phenyltrimethoxysilane was changed to trimethoxymethylsilane to obtain a cage silsesquioxane, and the reaction between the cage silsesquioxane and 1,7-dichlorooctamethyltetrasiloxane was not carried out. The polysiloxane of Example 3 had the following formula: The polysiloxane has a cage silsesquioxane structure represented by the formula (I) as a structural unit. The weight average molecular weight of this polysiloxane solution measured by gel permeation chromatography (GPC) was 33,000. A pellicle membrane was produced in the same manner as in Example 1. The membrane thickness of the obtained pellicle membrane was 6.0 μm. The obtained pellicle membrane was stretched and adhered to a frame to produce a pellicle.

[0088] Example 4 A polysilsesquioxane solution containing a cage-type silsesquioxane was prepared according to a known method (WO 2018 / 101213) as follows. In an argon atmosphere, a solution of i-Bu-substituted cyclic silanol (5.0 g, 0.010 mol) in diethyl ether (200 ml) was added dropwise to a solution of trichlorosilane (17 mL, 0.094 mol) and triethylamine (13 ml) in diethyl ether (200 ml) in an ice bath. The mixture was then stirred at room temperature for one day, and the solvent was distilled off under reduced pressure. Hexane (200 ml) was then added, and the mixture was filtered under argon to remove salts. The hexane was then removed to obtain a dichlorosiloxy compound of the cyclic silanol. Diethyl ether (200 ml) was added to the dichlorosiloxy compound of the cyclic silanol, and the resulting solution was added dropwise to a mixed solvent of acetone (400 ml) and water (50 ml) in an ice bath. After the dropwise addition, the mixture was stirred at room temperature for two days, and then stirred under reflux for one day. The solvent was removed using a rotary evaporator, and then the mixture was separated using diethyl ether and saturated saline. The crude product was separated using size exclusion chromatography and wet silica gel chromatography to obtain the target compound having a hydrogen atom as a substituent. The compound (1 g) obtained by the reaction represented by the above formula (1) was dissolved in 10 ml of toluene, dimethoxydimethylsilane (0.5 g) was added, and tris(pentafluorophenyl)borane (10 mg) was added while cooling to below 5° C., and the mixture was stirred at room temperature for 5 hours. The crude product was filtered and then concentrated to obtain the target compound. A polysiloxane solution containing a polysiloxane having a cage silsesquioxane structure was prepared in the same manner as in Example 1, except that the compound obtained by the reaction represented by the above formula (2) was used. The weight average molecular weight of this polysiloxane solution measured by gel permeation chromatography (GPC) was 35,000. A pellicle membrane was prepared in the same manner as in Example 1. The membrane thickness of the obtained pellicle membrane was 6.0 μm. The obtained pellicle membrane was stretched and adhered to a frame to prepare a pellicle.

[0089] Comparative Example 1: Pellicle membrane made of fluororesin A pellicle membrane was obtained in the same manner as in Example 1, except that a solution of a fluororesin (CYTOP CTX-809SP2 manufactured by AGC Inc.) diluted with a fluorine-based solvent (CYTOP CT-SLV manufactured by AGC Inc.) was used instead of the polysiloxane solution of Example 1. The thickness of the obtained pellicle membrane was 0.3 μm.

[0090] Comparative Example 2: Cellulose Pellicle Membrane A pellicle membrane was obtained in the same manner as in Example 1, except that an ethyl lactate solution of cellulose acetate propionate (CAP4 80-20, manufactured by Eastman Chemical Company) was used instead of the polysiloxane solution of Example 1. The thickness of the obtained pellicle membrane was 3.8 μm.

[0091] Comparative Example 3: Pellicle membrane made of polyladder siloxane A pellicle membrane was obtained in the same manner as in Example 1, except that a polyladder siloxane solution prepared according to a known method (JP-A-4-166840) was used instead of the polysiloxane solution in Example 1. The thickness of the obtained pellicle membrane was 3.0 μm.

[0092] [Measurement and Evaluation] <Transmittance Measurement Test> Using an ultraviolet-visible spectrophotometer (UV-1900i, manufactured by Shimadzu Corporation), the transmittance (%) of light having a wavelength of 190 nm or more and 440 nm or less was measured for the pellicle films of the Examples and Comparative Examples. In this Example, the average transmittance (%) was calculated in each of the ranges of 290 nm or more and 385 nm or less, 360 nm or more and 440 nm or less, 248 nm, and 193 nm. The results are shown in the table below.

[0093] <Exposure Test> The pellicle films of the Examples and Comparative Examples were attached to an aluminum frame (inner diameter 24 x 29 mm, outer diameter 35 x 40 mm), thereby obtaining test specimens. The obtained test specimens were irradiated with VUV light at an irradiation distance of 69 mm or 9 mm and for an irradiation time of 30 seconds or 1 minute, as shown in the table below. The VUV light irradiation conditions were as follows: (Irradiation Conditions) Light source: Xe Illuminance: 50 mW / cm ２ Oxygen concentration: 1000 ppm

[0094] <Puncture Test> The pellicle film after the above <Exposure Test> was attached to an aluminum frame with a circular hole of 7 mm diameter using double-sided tape so as to cover the hole, and an attempt was made to obtain a test specimen. When a test specimen was obtained, a load was applied to the test specimen using a tensile tester until the pellicle film broke, and the load (gf; maximum test force) at which the pellicle film broke was calculated. The maximum test force was calculated n = 4 times, and the average value obtained is shown in the table below. The maximum test force was calculated using the following apparatus and conditions. (Apparatus and Conditions) - Apparatus name: Autograph (SHIMAZU EZ-S, manufactured by Shimadzu Corporation) - Load cell: 10 N - Crosshead speed: 5 mm / min - Temperature: 21°C - Humidity: 50%

[0095] The results of the above measurements and evaluations are shown in the table below. In the table, "*" indicates that the pellicle membrane was ruptured during the process of preparing the test piece for the puncture test, making it impossible to measure.

[0096] As can be seen from the table above, the examples provided a pellicle film that exhibits excellent transmittance to light having wavelengths suitable for photolithography, while also ensuring mechanical strength and / or light resistance.

[0097] Furthermore, according to the examples, it has been confirmed that the present invention is suitable for lithography using ultraviolet light such as j-line (313 nm), i-line (365 nm), and h-line (405 nm), as well as a combination of these. Therefore, it is expected that the present invention will be able to meet the demands of next-generation electronic devices, such as the demand for even finer patterns.

[0098] The pellicle film and pellicle according to one embodiment of the present invention are suitable for use in dustproofing photomasks and the like in photolithography processes for forming semiconductors, LSIs, thin-film transistors (TFTs) constituting flat panel displays (FPDs), etc. The pellicle film and pellicle are suitable for lithography using j-line (313 nm), i-line (365 nm), h-line (405 nm), and ultraviolet light using these in combination as exposure light sources.

[0099] 1: Pellicle 2: Frame 2a: Long side 2b: Short side 3: Pellicle membrane 4: Ventilation hole 5: Filter 6: Membrane adhesive layer 7: Mask adhesive layer Op: Opening

Claims

1. A pellicle membrane containing a polysiloxane having a cage-type silsesquioxane structure.

2. The aforementioned polysiloxane, The following formula (i): 【Chemistry 1】 {In formula (i), R １１ , and R １２ Each of these independently represents a siloxy group (-OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxyl group (-OH), or a fluoro group (-F) that constitutes the polysiloxane. However, in formula (i), there are a total of four R １１ , and a total of four R １２ At least two of these represent the siloxy group (-OSi) that constitutes the polysiloxane.} Structure represented by The following formula (ii): 【Chemistry 2】 {In formula (ii), R ２１ , and R ２２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxy group (-OH), or a fluoro group (-F), and R ２３ , and R ２４ each independently represents a siloxy group (-OSi) constituting the polysiloxane, a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxy group (-OH), or a fluoro group (-F). However, in formula (ii), at least two of a total of two R ２３ , and a total of two R ２４ are siloxy groups (-OSi) constituting the polysiloxane.}, and the structure represented by The following formula (iii): 【Transformation 3】 {In formula (iii), R ３１ , and R ３２ Each of these independently represents a siloxy group (-OSi), a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxyl group (-OH), or a fluoro group (-F) that constitutes the polysiloxane. However, the five Rs in formula (iii) ３１ , and a total of five R's ３２ At least two of these are siloxy groups (-OSi) that constitute the polysiloxane.} Structure represented by The pellicle membrane according to claim 1, having at least one structure selected from the group consisting of the following.

3. The aforementioned polysiloxane, The following formula (I-1): 【Chemistry 4】 {In formula (I-1), R １１ , R １２ , and R ４１ Each of these independently represents a hydrocarbon group with 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxyl group (-OH), or a fluoro group (-F), and n represents an integer from 1 to 30. The structure represented by} The following formula (II-1): 【Transformation 5】 {In formula (II-1), R ２１ , R ２２ , R ２３ , and R ４１ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxyl group (-OH), or a fluoro group (-F), and n represents an integer from 1 to 30. The structure represented by}, The following formula (III-1): 【Transformation 6】 {In formula (III-1), R ３１ , R ３２ , and R ４１ Each of these independently represents a hydrocarbon group with 1 to 12 carbon atoms, a hydrogen atom (-H), a hydroxyl group (-OH), or a fluoro group (-F), and n represents an integer from 1 to 30. The structure is represented as}. The pellicle membrane according to claim 1 or 2, having at least one structure selected from the group consisting of the following.

4. In the aforementioned polysiloxane, The pellicle film according to claim 3, wherein the proportion of constituent units derived from the structures represented by formulas (i) to (iii) is 50% by mass or more, and / or the proportion of structures represented by formulas (I-1) to (III-1) is 50% by mass or more.

5. A pellicle comprising a frame and a pellicle membrane attached to the frame, A pellicle wherein the pellicle membrane is the pellicle membrane according to claim 1 or 2.

6. A compound solution for preparing pellicle membranes, containing a polysiloxane having a cage-like silsesquioxane structure.

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