Polysiloxane compositions, methods and uses thereof and products obtainable using the methods

Abstract

This invention relates to compositions comprising polysiloxane and compounds of formula (II), methods for preparing such compositions, methods for preparing porous polysiloxane membranes, porous polysiloxane membranes obtained by such methods, uses of such compositions and porous polysiloxane membranes, semiconductor devices comprising porous polysiloxane membranes, and methods for preparing semiconductor devices.

Description

Technical Field

[0001] This invention relates to a polysiloxane composition comprising a siloxane resin or a mixture of siloxane resins and a citrate ester as a pore-forming agent, and a low-refractive-index film obtained from the composition. Specifically, the invention relates to a polysiloxane composition comprising a polysiloxane and a citrate ester, a method for preparing the composition, a method for preparing a porous polysiloxane film, a porous polysiloxane film obtainable by said method, uses of the composition and the porous polysiloxane film, semiconductor devices comprising the porous polysiloxane film, and methods for preparing semiconductor devices. The composition can be used to fabricate anti-reflective coatings in optical waveguides, dielectric stacks, resonator structures, and other optical devices. Background Technology

[0002] Low refractive index (RI) is an important property for anti-reflective (AR) films, light-guiding optics, dielectric stacks in dielectric mirrors and dichroic filters, resonator structures, and other related applications such as augmented reality glasses. Currently, various types of low refractive index materials are used, the simplest being air, which has the lowest known refractive index of 1.0 among conventional materials. While air is sometimes used as a low refractive index / k gap in semiconductor devices, it lacks mechanical strength and is therefore difficult to incorporate into stacked structures. Consequently, there is a high demand in the optics and semiconductor industries for materials suitable for low refractive index / low k films. As used in this disclosure, "low refractive index" refers to 1.4 or lower, preferably 1.3 or lower, for example, a refractive index selected in the range of 1.05–1.4.

[0003] Fluorinated materials have traditionally been used as low-refractive-index and low-k coatings. These include films made of magnesium fluoride (MgF2) and fluorine-doped SiO2 (SiOF), as well as fluoroalkyl polymer films, whose refractive indices are typically between 1.3 and 1.4. Perfluoroalkyl polymers, such as PTFE, FEP, and PFA, also have low refractive indices but generally do not adhere well to other surfaces. Furthermore, the use of perfluoroalkyl substances (PFA) and fluoroalkyl substances (FAS) is subject to increasing regulation due to their high toxicity and environmental persistence.

[0004] Other common antireflective coatings are made from porous SiO2 nanoparticles, typically prepared using the so-called Stobber process with tetraethylsilicate (TEOS) and a weak base (e.g., an ammonia-ethanol solution). These solutions produce films with very low refractive indices (<1.25). However, because they consist of microporous spherical nanoparticle powder rather than a film-forming polymer solution, they lack structural integrity and can be easily wiped off with a bare finger. Furthermore, due to the low cracking threshold of these films, their maximum thickness is typically less than 1 μm, which greatly limits their applications.

[0005] Another low-refractive-index technique involves mixing hollow silica nanoparticles with a suitable binder. Hollow SiO2 particles are commercially available and are typically prepared using polystyrene nanoparticles as a sacrificial core. While a low refractive index can be achieved by minimizing the binder / nanoparticle ratio in these mixtures, these materials often produce unacceptably high haze due to light scattering from the hollow particles.

[0006] According to theory and Fresnel's equations, the thickness of a quarter-wavelength antireflective coating should be equal to λ / 4, where λ is the wavelength of light in the AR medium. The optimal refractive index (RI) of the AR medium can be considered as the square root of the substrate's RI. For example, the RI of soda-lime glass is 1.52, so the optimal RI of the AR coating is √1.52 = 1.23, with a thickness of 112 nm for green light (550 nm). For quartz, the RI is 1.45, and for magnesium fluoride (MgF2), the RI is 1.37. The best-performing AR coatings should have even lower RIs, such as 1.20 and 1.17. For effective antireflective coatings, materials with RIs below 1.3, preferably below 1.2, are required, and they should be able to be deposited as films.

[0007] In addition to anti-reflective coatings, low refractive index (RI) films are also used in QD-LCD and QD-OLED displays. These displays feature red and green arrays made of specific quantum dots (QDs) against a blue backlight, providing a wide color gamut. Because quantum dots are expensive, placing them between two low RI (RI < 1.25) resonator layers enhances their effect. This setup effectively increases the optical density of the QD layer, allowing it to be made thinner.

[0008] Various polysiloxane coatings are known in the art. KR20130075428A discloses a coating film with low reflectivity, high hardness, high transmittance, and a basic refractive index, which has a porous silica nanolayer structure. This coating has a porous silica nanolayer structure, in the form of a network of polysiloxane and silica mixture, and exhibits high hardness. The material has micropores and a low refractive index of less than 1.3, which can be adjusted by the volume ratio of silica to air.

[0009] WO2011013611A1 discloses a photosensitive resin composition that can be cured by active energy rays. This photosensitive resin composition provides a cured product with high hardness, good scratch resistance, adhesion, chemical resistance, stain resistance, and transparency, and a low refractive index. Furthermore, the film is made from the photosensitive resin composition and exists in the form of a hard coating film that can be prepared by curing the resin composition. The resin composition includes a polyfunctional (meth)acrylate having at least three (meth)acryloyl groups in its molecule, colloidal silica with a nanoporous structure having an average particle size of 1 to 200 nm, a (meth)acryloyl-containing polysiloxane, and a photoradical polymerization initiator.

[0010] EP1559761A1 discloses a coating solution for forming porous films with good mechanical strength and dielectric properties, and for readily forming films with freely controllable film thicknesses in methods commonly used in semiconductor processes. The porous film composition includes polysiloxanes, silica, or zeolite particles.

[0011] US20210301136 discloses a composition of polysiloxane and hydroxyalkylsiloxane that can provide a film with a low refractive index.

[0012] US6632748 discloses a siloxane resin composition in which nanoporosity is achieved by adding a cyclodextrin derivative (e.g., hepta(2,4,6-tri-O-methyl)-β-cyclodextrin) to the formulation. The cyclodextrin derivative decomposes at 420°C to form a film with nanoporosity and a refractive index below 1.4.

[0013] Zhong B. and Moyer E.S. described the fabrication of low-k siloxane films by curing isophytol-grafted HSQ resin at 470 °C. This temperature is high enough to thermally decompose the isophytol-derived alkyl chains, thereby forming nanoporous low-k, low-refractive-index films with an RI of approximately 1.18 to 1.22 (ACS Symposium Series Vol. 874, pp. 173-183, 2004).

[0014] As is evident from the aforementioned publications, many known low-refractive-index materials still exhibit high refractive indices. Some of these materials require curing temperatures exceeding 300°C to chemically decompose the components that form the pores, making them unsuitable for many devices containing heat-sensitive organic polymers and / or materials. Low-refractive-index materials based on fluoroalkyl chemistry may pose toxicity issues. Furthermore, unacceptably high haze can occur when using porous or hollow silica nanospheres or nanoparticles, as these particles are typically distributed across varying sizes, with the largest particles causing light scattering. Polymers with inherently low refractive indices due to nanopores in their polymer structures are generally rigid and exhibit poor gap-filling properties. Therefore, there remains a need for low-toxicity materials that can achieve high-quality optical low-refractive-index films with good gap-filling, compatibility, and adhesion on a variety of substrates, including glass, other inorganic oxides, and polymer substrates. Summary of the Invention

[0015] The summary portion of this invention is intended to introduce some concepts in a simplified form, which will be further described in the detailed description below. This summary portion is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0016] This invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims.

[0017] The object of the present invention is to provide a composition and a porous polysiloxane membrane to eliminate at least some of the problems associated with the art.

[0018] Surprisingly, the compositions disclosed in this disclosure can be used to prepare porous polysiloxane films with low refractive indices. The term "low refractive index" here and below means a refractive index of 1.4 or lower, preferably 1.3 or lower.

[0019] According to a first aspect of the invention, a composition is provided comprising a polysiloxane and a compound of formula (II):

[0020] in

[0021] R 1 R 2 and R 3 Each is independently selected from H, and linear, saturated, unsaturated or aromatic, branched or cyclic C. 1-15 - A hydrocarbon group, which optionally includes 1-4 heteroatoms, each heteroatom independently selected from oxygen, sulfur, nitrogen, and phosphorus; the condition is R 1 R 2 and R 3At least one of them is selected from linear, saturated, unsaturated or aromatic, branched or cyclic C 1-15 - A hydrocarbon group, which optionally includes 1 to 4 heteroatoms, each heteroatom being independently selected from oxygen, sulfur, nitrogen and phosphorus;

[0022] R 4 Selected from hydrogen, C 1-10 -acyl group, and linear, saturated or unsaturated, branched or cyclic C 1-10 - A hydrocarbon group, which optionally includes 1 to 4 heteroatoms, each heteroatom being independently selected from oxygen, nitrogen, phosphorus and sulfur.

[0023] According to a second aspect of the present invention, a method for preparing a composition as defined herein is provided, wherein the method comprises:

[0024] - Provide polysiloxanes or mixtures of polysiloxanes; and

[0025] - The composition is formed by mixing a polysiloxane or a mixture of polysiloxanes with a compound of formula (II).

[0026] According to a third aspect of the present invention, a method for preparing a porous polysiloxane membrane is provided, wherein the method comprises:

[0027] - Provide compositions as defined in this disclosure;

[0028] - The composition is applied to a substrate to form a polysiloxane layer on the substrate;

[0029] - Heating the formed polysiloxane layer to cure the polysiloxane; and

[0030] -At least partially remove the compound of formula (II),

[0031] - This forms a porous polysiloxane film on the substrate.

[0032] According to a fourth aspect of the present invention, a porous polysiloxane membrane is provided, which can be obtained by the method for preparing a porous polysiloxane membrane as defined in this disclosure, wherein the porous polysiloxane membrane comprises polysiloxane.

[0033] According to a fifth aspect of the present invention, the use of a porous polysiloxane film as defined in this disclosure in a photolithography method is provided.

[0034] According to a sixth aspect of the present invention, a semiconductor device comprising a porous polysiloxane film as defined herein is provided.

[0035] According to a seventh aspect of the present invention, the use of the compositions defined herein in the preparation of antireflective coating films in photoconductive optics, dielectric stacks, resonator structures, OLED devices, LED devices or other optical instruments, or in the preparation of antireflective coating films for nanoparticles or phosphor particles, or in methods of preparing semiconductor devices is provided.

[0036] According to an eighth aspect of the present invention, the use of the film as defined in this disclosure as a low-dielectric film in a semiconductor device, or in combination with a capping layer as a low-dielectric film or a low-refractive-index film, is provided.

[0037] According to a ninth aspect of the present invention, a method for fabricating a semiconductor device is provided, wherein the method comprises:

[0038] - Provide compositions as defined in this disclosure;

[0039] - The composition is applied to a substrate to form a polysiloxane layer on the substrate;

[0040] - Heating the formed polysiloxane layer to cure the polysiloxane;

[0041] - At least partially remove the compound of formula (II) to form a porous polysiloxane film on the substrate;

[0042] - The composition for the resist film is coated onto the porous polysiloxane film to form a resist film on the porous polysiloxane film;

[0043] - Irradiate the resist film with light along a predetermined pattern to form an irradiated structure of the resist film having irradiated resist film areas and unirradiated resist film areas;

[0044] - Develop the irradiation structure of the resist film to form a resist film with a resist pattern;

[0045] - The porous polysiloxane film is etched using the resist pattern of the resist film; and

[0046] - The semiconductor substrate is fabricated using the patterned resist film and the patterned porous polysiloxane film.

[0047] Further features and advantages of this technology will become apparent from the following detailed discussion of the embodiments.

[0048] Brief description of the attached figures

[0049] Figure 1An optical microscope image is shown in top view, showing no delamination after a tape test on a microlens array spin-coated with a formulation of Example 14 disclosed herein, comprising MB8 prepared according to Example 8 and MB6 prepared according to Example 8.

[0050] Figure 2 The image, taken by SEM, is shown in a side view, indicating that there is no delamination after tape testing of the microlens array, which is spin-coated with the formulation of Example 14 disclosed in this disclosure, comprising MB8 prepared according to Example 8 and MB6 prepared according to Example 8.

[0051] Figure 3 An optical microscope image is shown in top view, showing no delamination after a tape test on a microlens array spin-coated with a formulation of Example 14 disclosed herein, comprising MB8 prepared according to Example 8 and methyl isobutyl ketone.

[0052] Figure 4 A side view shows an image taken by SEM, which shows delamination after a tape test on a microlens array spin-coated with a formulation of Example 14 disclosed in this disclosure, which contains MB8 prepared according to Example 8 and methyl isobutyl ketone.

[0053] Figure 5 A side view shows an SEM image of a patterned Si wafer with lines (height 230 nm, width 85 nm, spacing 40 nm). The wafer is spin-coated with a formulation according to Example 15 disclosed herein, which comprises a citrate ester porogen prepared according to Example 2 disclosed herein, MB5 prepared according to Example 5 disclosed herein, and MB9 prepared according to Example 9 disclosed herein, and cured at 200 °C for 10 minutes.

[0054] Figure 6 A side view shows an SEM image of a patterned Si wafer with lines (height 230 nm, width 85 nm, spacing 40 nm), which was spin-cast using a solution containing MB8 and methyl isobutyl ketone as disclosed in Example 15 of this disclosure and cured at 200 °C for 10 minutes.

[0055] Figure 7 A graph showing the effect of the amount of compound of formula (II) obtained in Example 1 on the RI of the membrane obtained in Example 16 disclosed in this disclosure. Specific Implementation

[0056] The following explanations of terms and methods are provided to better describe the composition, porous polysiloxane membrane, semiconductor device, method, and use, and to guide those skilled in the art in practicing the present disclosure. It should also be understood that the terminology used in this disclosure is for describing specific embodiments and examples only and is not intended to be limiting.

[0057] It should be understood that the embodiments of the invention disclosed herein are not limited to the specific structures, processes, or materials disclosed herein, but extend to their equivalents as recognized by those skilled in the art. It should also be understood that the terminology used herein is for describing particular embodiments only and is not intended to be limiting.

[0058] The reference to "an embodiment" or "an embodiment" in this specification means that a particular feature, structure, or characteristic described in relation to that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment.

[0059] As used herein, for convenience, multiple items, structural elements, compositions, constituent elements, and / or materials may be presented in a common list. However, these lists should be interpreted as if each member of the list were individually identified as a separate and unique member. Therefore, unless otherwise stated, any single member of such a list should not be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group. Furthermore, various embodiments and examples of the invention, as well as alternatives to its various components, may be referenced herein. It should be understood that these embodiments, examples, and alternatives should not be construed as de facto equivalents of each other, but should be considered as separate and independent representations of the invention.

[0060] Furthermore, the described features, structures, or properties can be combined in any suitable manner in one or more embodiments. Numerous specific details, such as examples of weight, quantity, length, width, shape, etc., are provided in the following description to provide a comprehensive understanding of embodiments of the invention. However, those skilled in the art will recognize that the invention can be practiced without one or more specific details, or using other methods, components, polymers (e.g., polysiloxanes), materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the invention.

[0061] "Optional" or "optionally" indicates that the event or situation subsequently described may but not necessarily occur, and the description includes both cases where the event or situation occurs and cases where it does not occur. The same applies in the context of features; features subsequently described may or may not be included.

[0062] The verbs “comprising” and “including” are used in this document as open-ended restrictions, neither excluding nor requiring the presence of any undescribed features. “Comprising” or “including” indicates that a feature or action described subsequently may, but does not necessarily, include other features or actions. Unless otherwise expressly stated, the features described in the dependent claims may be freely combined with each other. Furthermore, it should be understood that the use of “a” or “an” (i.e., the singular form) in this document does not exclude the plural.

[0063] As used herein, all percentages (e.g., wt%) in the context of mass refer to the mass percentage of the total composition, solution, formulation, film, or layer, i.e., the mass of the compound (m). i ) as a percentage of the total mass of the composition, solution, formulation, film, or layer (m tot mass fraction (w) i ), the denominator is 100 (i.e. (m i / m tot ()*100), unless otherwise stated.

[0064] One object of the present invention is to provide novel compositions for preparing low-refractive-index polysiloxane films.

[0065] Another object of the present invention is to provide a novel low-refractive-index polysiloxane film that can be prepared as a layer with a thickness in the ultramicron range.

[0066] A third objective of this invention is to provide a method for preparing low-refractive-index polysiloxane films.

[0067] Surprisingly, the compositions disclosed in this disclosure can be used to prepare porous polysiloxane films with low refractive indices. The term "low refractive index" here and below refers to a refractive index of 1.4 or lower, preferably 1.3 or lower. Without being bound by any theory, we believe that the compounds (or mixtures thereof) of formula (II) disclosed in this disclosure can be used as pore-forming agents together with polysiloxanes. Therefore, the compositions disclosed in this disclosure can be used to prepare porous polysiloxane films with low refractive indices on substrates, even on substrates containing thermosensitive materials (e.g., thermosensitive organic polymers). Furthermore, the compositions disclosed in this invention are non-toxic, and porous polysiloxane films prepared from the compositions disclosed in this invention have been found to be non-rigid and possess good gap-filling properties. Moreover, it is surprising that porous polysiloxane films prepared from the compositions disclosed in this invention exhibit good compatibility and adhesion on a variety of substrates, including glass, other inorganic oxides, and polymer substrates.

[0068] Therefore, the present invention has significant advantages.

[0069] According to a first aspect of the invention, a composition is provided comprising a polysiloxane and a compound of formula (II):

[0070] in

[0071] R 1 R 2 and R 3 Each is independently selected from H, and linear, saturated, unsaturated or aromatic, branched or cyclic C. 1-15 - A hydrocarbon group, which optionally includes 1-4 heteroatoms, each heteroatom independently selected from oxygen, sulfur, nitrogen, and phosphorus; the condition is R 1 R 2 and R 3 At least one of them is selected from linear, saturated, unsaturated or aromatic, branched or cyclic C 1-15 - A hydrocarbon group, which optionally includes 1 to 4 heteroatoms, each heteroatom being independently selected from oxygen, sulfur, nitrogen and phosphorus;

[0072] R 4 Selected from hydrogen, C 1-10 -acyl group, and linear, saturated or unsaturated, branched or cyclic C 1-10 - A hydrocarbon group, which optionally includes 1 to 4 heteroatoms, each heteroatom being independently selected from oxygen, nitrogen, phosphorus and sulfur.

[0073] Compounds of formula (II) can be called citrate esters. These are generally considered safe compounds and solvents.

[0074] Surprisingly, by providing a composition comprising a polysiloxane (polysiloxane resin) or a mixture of polysiloxanes and a compound of formula (II) (citric acid ester), a porous polysiloxane film with excellent properties such as low refractive index, low haze, and optionally low dielectric constant can be obtained. The compound of formula (II) can be evaporated by heating the composition or removed by washing away cured polysiloxane obtained by curing the composition. Therefore, a porous polysiloxane film or layer can be obtained by heating such a composition before and / or during the curing of the polysiloxane to form a polysiloxane film.

[0075] The term "porous polysiloxane membrane" as used herein and hereinafter refers to a polysiloxane membrane containing pores. The term "pore" as used herein and hereinafter refers to voids within a polysiloxane membrane. The porosity of a polysiloxane membrane can be defined as the volume fraction of voids within the polysiloxane membrane. Pores may have, for example, but not limited to, a circular cross-sectional shape, and the pore diameter may correspond to the diameter of the circular cross-section of the pore.

[0076] Alternatively, porous polysiloxane membranes may include multiple pores.

[0077] Alternatively, the aperture of the plurality of pores may be selected from the range of 0.1–1000 nm, more preferably from the range of 0.1–400 nm, and even more preferably from the range of 0.1–100 nm.

[0078] Alternatively, polysiloxanes may be mixed polycarbosilane-siloxanes.

[0079] As used herein and hereinafter, the term "film" refers to a layer located on the surface of a substrate or on the surface of another film (or layer). Therefore, the terms "film" and "layer" are used interchangeably in this disclosure.

[0080] Furthermore, this invention allows for the use of compositions comprising polysiloxanes with enhanced gap-filling properties. These compositions can fill gaps as narrow as tens of nanometers to prepare void-free, low-refractive-index porous polysiloxane films. Moreover, the present compositions can produce films with the mechanical integrity required for the applications mentioned in this disclosure.

[0081] Furthermore, the compound of formula (II) was unexpectedly found to be highly compatible with polysiloxanes. Unbound by any theory, we believe this may be due to the polarity of the three C=O groups in the citrate core, and if R... 4 If the molecule is H, then a free tertiary hydroxyl group exists. Furthermore, without being bound by any theory, if the porogen is poorly compatible with the polysiloxane (or another compound or material used to prepare the film on the substrate), the porogen phase may separate into small droplets, leaving macropores after evaporation. If these macropores are larger than 1 / 4 of the wavelength, they may interact with light; that is, macropores larger than 100 nm may interact with blue light (400 nm wavelength). This interaction may lead to haze. The porous polysiloxane film (layer) formed by this invention may have low haze because the solubility of the polysiloxane and the compound of formula (II) (or a mixture of compounds of formula (II)) is well matched, resulting in fine porosity, rather than a high-haze film caused by phase separation of incompatible polysiloxane and high-boiling-point porogen solvent. The porous polysiloxane film disclosed in this invention can withstand high temperatures up to 800°C without damaging its porosity or changing its refractive index, exhibiting excellent thermal stability.

[0082] Alternatively, the composition may be a composition for preparing porous polysiloxane membranes that do not contain or substantially do not contain compounds of formula (II).

[0083] Alternatively, the composition may be a composition for preparing a porous polysiloxane membrane that is free of or substantially free of compounds of formula (II), and the porous polysiloxane membrane comprises crosslinked polysiloxane.

[0084] Alternatively, the composition may be a composition for preparing optical devices.

[0085] Alternatively, the composition may be a composition for preparing a porous polysiloxane membrane, wherein the porous polysiloxane membrane has a refractive index of 1.5 or less, preferably 1.4 or less, more preferably 1.3 or less, even more preferably 1.2 or less, and even more preferably 1.1 or less.

[0086] Alternatively, the composition may be a composition for preparing a porous polysiloxane film, wherein the refractive index of the low-refractive-index siloxane film is 1.5 or less, preferably 1.4 or less, more preferably 1.3 or less, even more preferably 1.2 or less, even more preferably 1.1 or less; and wherein the dielectric constant of the low-refractive-index siloxane film is 1.5 or less, for example 1.4.

[0087] In addition, or alternatively, the composition does not contain plasticizers.

[0088] Alternatively, polysiloxanes may be non-crosslinked polysiloxanes.

[0089] In addition, or alternatively, the polysiloxane in the mixture of polysiloxanes is a non-crosslinked polysiloxane.

[0090] Alternatively, the composition may contain two or more polysiloxanes, wherein one of the two or more polysiloxanes is a non-crosslinked polysiloxane.

[0091] Alternatively, based on 10 parts by weight of the polysiloxane, the composition comprises 3–150 parts by weight, particularly 5–100 parts by weight, for example 5–80 parts by weight of the compound of formula (II). Alternatively, R 1 R 2 and R 3 Each is independently selected from linear, saturated, unsaturated, or aromatic, branched, or cyclic C. 1-15 - A hydrocarbon group, which optionally contains 1–4 heteroatoms, each heteroatom being independently selected from oxygen, sulfur, nitrogen and phosphorus.

[0092] In addition, or alternatively, R 1 R 2 and R 3 Each is independently selected from the group consisting of methyl, ethyl, n-butyl, 2-tert-butoxyethoxy, 3-methoxybutoxy, and (tetrahydrofuran-2-yl)methoxy. Alternatively, R 1 R 2 and R 3 Each is independently selected from the group consisting of methyl, ethyl, n-butyl, 2-tert-butoxyethoxy, 3-methoxybutoxy, and (tetrahydrofuran-2-yl)methoxy, preferably, R 1 R2 and R 3 Selected from the group consisting of methyl, ethyl, n-butyl, 2-tert-butoxyethoxy, 3-methoxybutoxy, and (tetrahydrofuran-2-yl)methoxy; and R 4 The group is H or acetyl. These compositions are specifically formed with polysiloxanes in a manner as disclosed in this disclosure to form a uniform film. Furthermore, the RI of the cured polysiloxane film is lower than that of a film made from a composition having a polymer but not a compound of formula (II) (i.e., a porogen). Additionally, by changing, for example, the RI... 1 R 2 and R 3 The size of the alkyl group can be adjusted to control the evaporation rate of the compound of formula (II) to match the thermal stability of the substrate. For example, many plastics used in photolithography and optical devices can only be cured below 130°C without deformation, thus requiring shorter alkyl chains. Conversely, inorganic substrates such as glass can be cured at higher temperatures, allowing the R-chain structure of the compound of formula (II) to be more flexible and stable. 1 R 2 and R 3 The alkyl chains in the group are relatively long. Therefore, this allows compositions containing polysiloxanes and compounds of formula (II) to be used on a variety of substrates, such as, but not limited to, plastics (which do not deform) that cure below 130°C and glass (which can be cured at higher temperatures). Thus, the compositions disclosed in this disclosure have a wide range of applications.

[0093] Furthermore, the compositions disclosed herein can be further enhanced by surfactants and curing catalysts to optimize film quality and enable curing at low temperatures, such as 150°C or lower, or even 100°C or lower, or under ultraviolet or visible light irradiation. Additionally, patterned low-refractive-index films can be created using ultraviolet light and photomasks or laser patterning.

[0094] In addition, or alternatively, R 4 It is selected from hydrogen, acetyl, propionyl and butyryl.

[0095] In addition, or alternatively, R 4 Selected from linear, saturated or unsaturated, branched or cyclic C 5-10 - A hydrocarbon group, which optionally contains 1–4 heteroatoms, each heteroatom being independently selected from oxygen, nitrogen, phosphorus and sulfur.

[0096] In addition, or optionally, the composition may also contain surfactants and / or toughening agents.

[0097] In addition, or alternatively, the composition may further include one or more surfactants, wherein the content of the one or more surfactants is 0 to 10 wt% based on the total weight of the composition. In addition, or alternatively, the content of the one or more surfactants may be selected from fluorosurfactants, siloxane surfactants, nonionic surfactants, anionic or cationic surfactants, or amphoteric surfactants.

[0098] Alternatively, the toughening agent may be linear C. 1-20 - Hydrocarbon polysiloxane, linear C 1-20 - Hydrocarbon silanes or linear siloxanes-carbon silane polymers, or mixtures thereof. Advantageously, these embodiments can be used to obtain crack-free porous polysiloxane membranes with improved crack resistance.

[0099] As used in this disclosure, the term "siloxane" can refer to polysiloxane and is an organic compound containing a functional group of two silicon atoms bonded to an oxygen atom: Si-O-Si. Examples of siloxanes include, but are not limited to, polydimethylsiloxane.

[0100] Alternatively, polysiloxanes can be schematically represented as follows:

[0101] Each group is represented by a wavy bond, and each R is independently selected from linear, saturated, unsaturated, or aromatic, branched, or cyclic C. 1-20 - A hydrocarbon group, optionally comprising 1-4 heteroatoms, each heteroatom independently selected from the group consisting of oxygen, silicon, nitrogen, sulfur, and phosphorus, and optionally substituted by 1-4 substituents, each substituent independently selected from halogen, OH, isopropenyl carbonyloxy, vinyl carbonyloxy, (ethylene oxide-2-yl)methoxy, SH, N(CH3)2, 2-aminoethylamino, C 2-10 -alkyl, 7-oxabicyclo[4.1.0]hept-3-yl, C 2-10 -Alkenyl and C 6-10 -Aryl. In the above representation of polysiloxanes, the wavy bond can be understood as a connection point with other regions of the polymer molecule, which are not shown in the above representation due to their complexity.

[0102] Alternatively, the polysiloxane may be a prepolymer with an average molecular weight of 500 to 10,000,000 g / mol, preferably 1,000 to 1,000,000 g / mol, for example 5,000 to 100,000 g / mol or 20,000 to 50,000 g / mol, measured by GPC against a polystyrene standard. The prepolymer may be a polysiloxane obtained by hydrolysis and condensation or co-condensation of a silane monomer or a mixture of silane monomers.

[0103] In this context, the term "prepolymer" is used to refer to a polysiloxane that is still curable or crosslinkable. Therefore, the term "prepolymer" also indicates that the polysiloxane is "non-crosslinkable," meaning that it is capable of undergoing a crosslinking reaction to achieve a hardened (i.e., cured) structure.

[0104] Furthermore, or alternatively, the compounds of formula (II) have a boiling point of at least 70°C at 1 mbar. Furthermore, or alternatively, the compounds of formula (II) have a boiling point of less than 260°C at pressures from 0.01 to 1 mbar. Furthermore, or alternatively, R 1 R 2 and R 3 Each compound is independently selected from alkyl groups of sufficient polarity to completely or at least partially dissolve a polysiloxane (siloxane resin) or a mixture of polysiloxanes (siloxane resins). When these compounds of formula (II) are used in a method for preparing porous polysiloxane membranes as disclosed in this disclosure, this can produce transparent, porous, preferably nanoporous polysiloxane membranes with high optical transparency.

[0105] Alternatively, polysiloxanes are polymers having an average molecular weight (Mw) of 500–1,000,000 g / mol, particularly 1,000–1,000,000 g / mol or 1,000–1,000,000 g / mol.

[0106] Alternatively, polysiloxanes are polymers having an average molecular weight (Mw) of 500–1,500,000 g / mol, particularly 1,000–100,000 g / mol.

[0107] Polysiloxanes can be polymers of one or more silane monomers. Typically, polysiloxanes can be obtained by hydrolysis and condensation or co-condensation of one or more silane monomers. Therefore, it should be understood that one or more silane monomers can be first hydrolyzed (with water), and then the hydrolyzed one or more silane monomers can be condensed or co-condensed to form a polysiloxane. Examples of such silane monomers include, but are not limited to, hexamethylcyclotrisiloxane (hexamethyl-1,3,5,2,4,6-trioxatrisiloxane), 1,1,4,4,7,7-hexamethyl-1,4,7-trisiloxane, 1,1,3,3,5,5-hexamethyl-1,3,5-trisiloxane, 1,1,4,4-tetramethyl-1,4-disiloxane, tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, vinyltrimethoxysilane, epoxypropoxypropyltrimethoxysilane, phenyltrimethoxysilane, and methacryloxypropyltrimethoxysilane.

[0108] Alternatively, polysiloxanes can be obtained by providing one or more siloxane polymers, hydrolyzing one or more siloxane polymers, and polycondensing the hydrolyzed silane monomers to form non-crosslinked polysiloxanes. The composition can be obtained by mixing the non-crosslinked polysiloxane with a compound of formula (II) capable of at least partially dissolving the non-crosslinked polysiloxane, optionally with a spin-casting solvent for the non-crosslinked polysiloxane.

[0109] Alternatively, the composition may include a compound of formula (II) which has an optimal evaporation rate during the heating of the polysiloxane layer to cure the polysiloxane and / or at least partially remove (preferably by evaporation) the compound of formula (II), thereby forming a porous polysiloxane film on the substrate.

[0110] In addition, or alternatively, R 1 R 2 and R 3 Whether the two are the same or different, it is possible to optimize the compatibility between the siloxane resin and the compound of formula (II) and to fine-tune the properties of the cured film (i.e., the porous polysiloxane film).

[0111] Alternatively, the polysiloxane may be a polysiloxane of one or more silane monomers, each of which is independently selected from the group consisting of silane monomers having the formulas (IVa), (IVb), (IVc), (IVd), and (IVe):

[0112] as well as

[0113] in,

[0114] Z 1 Z 2 Z 3 Z 4 Z 5 Z 6 Z 7 and Z 8 Each is independently selected from hydrolyzable and non-hydrolyzable groups, but Z 1 Z 2 Z 3 Z 4 Z 5 Z 6 Z 7 and Z 8 At least one of them is a hydrolyzable group;

[0115] Each hydrolyzable group is independently selected from C 1-15 -alkoxy groups, halogens and C 1-15 The group composed of -carboxylate groups;

[0116] Each non-hydrolyzable group is independently selected from straight-chain, saturated, unsaturated, or aromatic, branched, or cyclic C groups. 1-20 - A hydrocarbon group, optionally comprising 1–4 heteroatoms, each heteroatom independently selected from oxygen, silicon, nitrogen, sulfur, and phosphorus, and optionally substituted by 1–4 substituents, each substituent independently selected from halogen, OH, isopropenyl carbonyloxy, vinyl carbonyloxy, (ethylene oxide-2-yl)methoxy, SH, N(CH3)2, 2-aminoethylamino, C 2-10 -alkyl, 7-oxabicyclo[4.1.0]hept-3-yl, C 2-10 -Alkenyl and C 6-10 -Aryl;

[0117] Each R 5 Independently selected from CH2 and CH2CH2;

[0118] Each R 6 Independently selected from CH2 and O;

[0119] R 7 Independently selected from (CH2) n O, where n is an integer selected from 1 to 10.

[0120] Alternatively, the polysiloxane may be obtained by hydrolysis, condensation or co-condensation of one or more silane monomers, each of which is independently selected from the group consisting of silane monomers having the formula (IVa), (IVb), (IVc), (IVd) and / or (IVe) as defined in this disclosure.

[0121] Alternatively, the polysiloxane is a polysiloxane comprising one or more repeating units, wherein each of the one or more repeating units is independently selected from the group consisting of monomers having the formulas (Va), (Vb), (Vc), (Vd), and (Ve):

[0122]

[0123] Among them, Z 1 Z 2 Z 3 Z 4 Z 5 Z 6 Z 7 Z 8 R 5 R 6 and R 7 As defined in this disclosure; and each x is an independent integer selected from 1 to 10,000,000.

[0124] In addition, or alternatively, C 1-15-Alkoxy groups are selected from methoxy, ethoxy, and propoxy groups.

[0125] Alternatively, halogens may be selected from Cl and Br.

[0126] In addition, or alternatively, C 1-15 -The carboxyl group is selected from acetoxy and propionyl groups.

[0127] Alternatively, each non-hydrolyzable group may be independently selected from linear, branched, or cyclic C groups. 2-10 -Alkenyl, C 2-10 -Alynyl group, C 5-10 -Aryl and linear, branched or cyclic C 1-20 -alkyl, preferably linear, branched or cyclic C 1-10 -alkyl group, optionally containing 1–4 heteroatoms, each heteroatom being independently selected from the group consisting of oxygen, silicon, nitrogen, sulfur and phosphorus.

[0128] In addition, or alternatively, each non-hydrolyzable group is selected from methyl, ethyl, propyl, vinyl, phenyl, benzyl, dimethylphenyl, trimethylphenyl, tetramethylphenyl, naphthyl, diethylphenyl, mercaptopropyl, chloromethyl, 3-[2,4,6-trioxo-3,5-bis(prop-2-enyl)-1,3,5-triazin-1-yl]propyl, methacryloyloxypropyl, epoxypropoxypropyl, 3,4-epoxy-cyclohexylethyl, dimethylaminopropyl and aminoethylaminopropyl.

[0129] Alternatively, the polysiloxane may have a refractive index of 1.6 or less, preferably 1.5 or less.

[0130] In addition, or alternatively, the composition may also include a solvent, preferably in an amount of 1-99.9 wt% based on the total weight of the composition, more preferably 5-99 wt%.

[0131] Alternatively, the solvent may be selected from polar or nonpolar solvents and proton or aproton solvents.

[0132] Alternatively, the solvent may be selected from C 1-15 Alkanes, C 2-15 Ester, C 3-15 Ketones, C 2-15 Ethers and C 1-15 The alcohol, preferably, is propylene glycol n-propyl ether (PnP) as the solvent. Alternatively, the solvent may be selected from PGMEA, PnP, IPA, and MEK.

[0133] In addition, or alternatively, the composition may also contain one or more solvents, preferably in an amount of 1–99.9 wt% based on the total weight of the composition, more preferably 5–99 wt%.

[0134] Alternatively, one or more solvents may be selected independently from short-chain linear, cyclic dimethyl silicone oils (polydimethyl silicone oils) with boiling points between 30 and 300 °C under ambient pressure.

[0135] In a preferred embodiment, one or more solvents are each independently selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol, tert-butanol, isomers of pentanol, ethyl acetate, propyl acetate, butyl acetate, pentanol acetate, cyclohexyl acetate, PGMEA, PGME, PGEE, PnP, methoxybutyl acetate, methyl isobutyl ketone (MIBK), methyl ethyl ketone, diethyl ketone, diisopropyl ketone, pentyl formate, methyl 3-methoxypropionate, cyclohexanone, and cyclopentanone. tert-butyl acetate, 2-tert-butoxyethanol, tert-amyl alcohol, methyl isobutyl carbitol, methyl isobutyl ketone and octamethyltrisiloxane, decamethylcyclopentylsiloxane, dodecylcyclohexylsiloxane, 3,5,5-trimethyl-1-hexanol, toluene, ethylbenzene, xylene, mesitylene, anisole, α,α,α-trifluorotoluene, methyl, ethyl or propyl acetoacetate, diethylene glycol butyl acetate, ethylene glycol methyl ethyl ether, furfuryl alcohol, tetrahydrofurfuryl alcohol, isobutyl acetate, benzyl alcohol, γ-butyrolactone, cyclopentyl methyl ether.

[0136] In addition, or alternatively, the composition may further include one or more curing catalysts, preferably in an amount of 0.001-20 wt% based on the total weight of the composition, more preferably 0.001-10 wt%.

[0137] In addition, or alternatively, the composition may further include one or more curing catalysts, each independently selected from the group consisting of free radical initiators, anionic initiators, cationic initiators, or phosphazene-type silanol condensation catalysts, thermally induced free radical catalysts, photo-induced free radical catalysts, tin-containing catalysts, platinum-containing catalysts, basic catalysts, basic release catalysts, acidic catalysts, thermally or photo-released acidic catalysts, and fluoride ion release catalysts. The initiator may be activated by heat or light.

[0138] In addition, or alternatively, the composition may also include 0–10 wt% of one or more stabilizers and / or 0–10 wt% of one or more inhibitors based on the total weight of the composition.

[0139] The one or more stabilizers and / or one or more inhibitors are each independently selected from the group consisting of benzotriazole derivatives, phenols, catechols or hydroquinones, hydroxylamines, p-phenylenediamine type free radical inhibitors, weak acids or weak bases or their salts.

[0140] Alternatively, at a pressure of 1 mbar, the temperature difference between the boiling point of the compound of formula (II) and the curing temperature of the polysiloxane is 100°C or less, preferably 50°C or less.

[0141] According to a second aspect of the present invention, a method for preparing a composition as defined herein is provided, wherein the method comprises:

[0142] - Provide polysiloxanes or mixtures of polysiloxanes; and

[0143] - The composition is formed by mixing a polysiloxane or a mixture of polysiloxanes with a compound of formula (II).

[0144] Alternatively, polysiloxanes may be non-crosslinked polysiloxanes.

[0145] In addition, or alternatively, mixtures of polysiloxanes may include non-crosslinked polysiloxanes.

[0146] Alternatively, the polysiloxane or a mixture of polysiloxanes may be provided in a solvent; or the polysiloxane or a mixture of polysiloxanes may be mixed in a solvent with a compound of formula (II).

[0147] Alternatively, a non-crosslinked polysiloxane or a mixture of polysiloxanes may be provided in a solvent; or a mixture of non-crosslinked polysiloxanes or a mixture of polysiloxanes may be mixed with a compound of formula (II) in a solvent.

[0148] Alternatively, the solvent may be selected from C 1-15 Alkanes, C 2-15 Ester, C 3-15 Ketones, C 2-15 Ethers and C 1-15 The alcohol, preferably, is propylene glycol n-propyl ether (PnP) as the solvent. Alternatively, the solvent may be selected from PGMEA, PnP, IPA, and MEK.

[0149] Alternatively, the method may be free of plasticizers.

[0150] According to a third aspect of the present invention, a method for preparing a porous polysiloxane membrane is provided, wherein the method comprises:

[0151] - Provide compositions as defined in this disclosure;

[0152] - The composition is applied to a substrate to form a polysiloxane layer on the substrate;

[0153] - Heating the formed polysiloxane layer to cure the polysiloxane; and

[0154] -At least partially remove the compound of formula (II),

[0155] - This forms a porous polysiloxane film on the substrate.

[0156] Alternatively, the step of heating the formed polysiloxane layer to cure the polysiloxane is or includes: heating the formed polysiloxane layer to cure the polysiloxane and at least partially removing the compound of formula (II). In these embodiments, the step of heating the formed polysiloxane layer is to cure the polysiloxane and at least partially remove the compound of formula (II) (preferably by evaporation), thereby forming a porous polysiloxane film on the substrate. Alternatively, the step of heating the formed polysiloxane layer to cure the polysiloxane and at least partially removing the compound of formula (II) involves heating the formed polysiloxane layer to cure the polysiloxane, and during and / or after heating the formed polysiloxane layer to cure the polysiloxane, evaporating the formed polysiloxane layer to at least partially remove the compound of formula (II), thereby forming a porous polysiloxane film on the substrate.

[0157] By at least partially removing the compound of formula (II), preferably by evaporating the formed polysiloxane layer to at least partially remove the compound of formula (II), a porous polysiloxane film or structure with a low refractive index and a low dielectric constant can be produced. Typically, these porous polysiloxane resins produce materials with a refractive index of 1.4 or lower, such as 1.3 or lower, even 1.1, and a dielectric constant of 1.5 or lower, such as 1.4. Alternatively, the porosity of the film can be achieved by using a lower curing temperature (e.g., a temperature selected from the range of 70–180°C or 70–130°C) and by at least partially washing away the compound of formula (II) with a low-boiling-point solvent (rather than evaporation). The low-boiling-point solvent can be (but is not limited to) PGMEA, acetone, or isopropanol, or combinations thereof, or other solvents that dissolve the compound of formula (II) (i.e., porogens), and can be evaporated at a lower temperature than the porogen, such as at 80°C. This method is applicable to plastic substrates.

[0158] Alternatively, the compound of formula (II) may be at least partially removed by evaporation-cured polysiloxane to at least partially remove the compound of formula (II).

[0159] Alternatively, at least partially removing the compound of formula (II) may be done by washing the cured polysiloxane with a low-boiling-point solvent to at least partially remove the compound of formula (II), wherein the boiling point of the low-boiling-point solvent is lower than that of the compound of formula (II).

[0160] Alternatively, a method for preparing a porous polysiloxane membrane is provided, wherein the method includes:

[0161] - Provide compositions as defined in this disclosure;

[0162] - The composition is applied to a substrate to form a polysiloxane layer on the substrate;

[0163] - Heating the formed polysiloxane layer to cure the polysiloxane; and

[0164] - The cured polysiloxane is washed with a low-boiling-point solvent to at least partially remove the compound of formula (II), wherein the boiling point of the low-boiling-point solvent is lower than that of the compound of formula (II).

[0165] - This forms a porous polysiloxane film on the substrate.

[0166] Alternatively, the low-boiling-point solvent may be selected from PGMEA, acetone and isopropanol, or combinations thereof.

[0167] Alternatively, the substrate may be a semiconductor substrate.

[0168] Alternatively, the composition may comprise one or more solvents, such as one or more casting solvents, each independently selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol, tert-butanol, isomers of pentanol, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, cyclohexyl acetate, PGMEA, PGME, PGEE, PnP, methoxybutyl acetate, MIBK, methyl ethyl ketone, diethyl ketone, diisopropyl ketone, amyl formate, methyl 3-methoxypropionate, etc. Cyclohexanone, cyclopentanone, tert-butyl acetate, 2-tert-butoxyethanol, tert-pentanol, methyl isobutyl carbitol, methyl isobutyl ketone and octamethyltrisiloxane, decamethylcyclopentanol, dodecylcyclohexylsiloxane, 3,5,5-trimethyl-1-hexanol, toluene, ethylbenzene, xylene, mesitylene, anisole, α,α,α-trifluorotoluene, methyl, ethyl or propyl acetoacetate, diethylene glycol butyl acetate, ethylene glycol methyl ethyl ether, furfuryl alcohol, tetrahydrofurfuryl alcohol, isobutyl acetate, benzyl alcohol, γ-butyrolactone, cyclopentyl methyl ether.

[0169] Alternatively, the polysiloxane layer formed by heating may include heating the polysiloxane layer at a temperature selected from 70–250°C, preferably at a temperature selected from 100–210°C, and more preferably at a temperature selected from 110–200°C.

[0170] In addition, or alternatively, the composition may further include one or more curing catalysts; the polysiloxane layer formed by heating includes heating the polysiloxane layer at a temperature selected from 70–250°C, preferably at a temperature selected from 100–210°C, and more preferably at a temperature selected from 110–200°C.

[0171] Alternatively, the step of forming the polysiloxane layer by heating may include soft-baking the polysiloxane layer formed at a temperature selected from 70–180°C, preferably 100–160°C, more preferably 110–150°C, and curing the soft-baked layer at a temperature selected from 140–270°C, preferably 170–250°C, more preferably 190–230°C. Alternatively, the step of forming the polysiloxane layer by heating may include soft-baking the polysiloxane layer formed at a temperature selected from 110–120°C for 1–5 minutes, preferably 2–4 minutes, and curing the soft-baked layer at a temperature selected from 190–200°C for 1–60 minutes, preferably 2–15 minutes. These embodiments allow for the removal of low-boiling-point solvents (e.g., casting solvents) during soft baking, followed by curing of the film and removal of the compound of formula (II) during curing. Thus, a preferred porous polysiloxane film with good performance can be obtained. Alternatively, the formed polysiloxane layer can be "gelled" during soft baking. That is, the formed polysiloxane layer can be made insoluble, in a gel-like state. Then, when the compound of formula (II) is removed during curing, a higher porosity and a slightly lower RI can be obtained for the porous polysiloxane membrane.

[0172] In addition, or alternatively, the composition may also include one or more curing catalysts;

[0173] The step of curing the polysiloxane layer formed by heating includes curing the formed polysiloxane layer at a temperature selected from the range of 70–180°C, preferably 100–160°C, more preferably 110–150°C, and...

[0174] The step of at least partially removing the compound of formula (II) is to heat-cure the polysiloxane layer to at least partially remove the compound of formula (II), preferably at a temperature selected from the range of 140–270°C, 170–250°C or 190–230°C to at least partially remove the compound of formula (II).

[0175] Alternatively, the step of applying the composition to the substrate may be to spin-coat, spin-cast, spray, dip-coat, spin-coat, spray, dip-coat, slot-coat, or inkjet-coat the composition onto the substrate. This yields a porous polysiloxane film with a refractive index of 1.4 or lower, preferably even 1.1 or lower.

[0176] Alternatively, the polysiloxane layer formed by heating is performed using a heating plate, oven, or infrared radiation. Alternatively, evaporation is performed using an evaporator. The formed polysiloxane layer can be cured and hardened before the compound of formula (II) is completely or at least partially removed (e.g., evaporated), leaving a porous polysiloxane membrane structure, such as a nanoporous polysiloxane membrane.

[0177] According to a fourth aspect of the present invention, a porous polysiloxane membrane is provided, which can be obtained by the method for preparing a porous polysiloxane membrane as defined in this disclosure, wherein the porous polysiloxane membrane comprises polysiloxane.

[0178] Furthermore, or alternatively, the average pore size of the porous polysiloxane membrane is 0.1–1000 nm, more preferably 0.1–400 nm, and most preferably 0.1–100 nm. Surprisingly, the porous polysiloxane membrane exhibits fine porosity, rather than a high-haze membrane caused by phase separation of the incompatible polysiloxane and the high-boiling-point pore-forming solvent. The obtained porous polysiloxane membrane can withstand heat up to 800°C without damaging its porosity or altering its refractive index, exhibiting excellent thermal stability. Furthermore, the obtained porous polysiloxane membrane has a low refractive index. The term "low refractive index" here and below refers to a refractive index of 1.4 or lower, preferably 1.3 or lower. Moreover, porous polysiloxane membranes with low refractive indices can be obtained on substrates containing thermosensitive materials (e.g., thermosensitive organic polymers). Furthermore, it has been found that porous polysiloxane membranes prepared from the compositions disclosed in this disclosure may not be rigid and may have good gap-filling properties. Furthermore, it has been surprisingly found that porous polysiloxane films prepared from the compositions disclosed in this disclosure exhibit good compatibility and adhesion on a variety of substrates, including glass, other inorganic oxides and polymer substrates.

[0179] In addition, or alternatively, porous polysiloxane membranes are essentially free of compounds of formula (II).

[0180] In addition, or alternatively, porous polysiloxane membranes are essentially free of plasticizers.

[0181] Alternatively, the thickness of the porous polysiloxane membrane may be at least 10 nm.

[0182] Alternatively, the porous polysiloxane film may have a refractive index of 1.5 or lower, preferably 1.4 or lower, and more preferably 1.3 or lower.

[0183] Alternatively, the porous polysiloxane membrane may contain a toughening agent, preferably a linear C24-C ... 1-20 - Hydrocarbon polysiloxane, linear C 1-20 - Hydrocarbon silanes or linear siloxanes-carbon silane polymers, or mixtures thereof. These embodiments allow for the achievement of higher porous polysiloxane film thicknesses without film cracking. Thicknesses selected from the range of 2–5 μm can even be achieved without cracking.

[0184] Alternatively, porous polysiloxane membranes or compositions as defined in this disclosure, wherein C1-20 - Hydrocarbon polysiloxanes contain at least one functional group selected from epoxy, amino, isocyanurate, mercapto, acryloyl, methacryl, alkenyl, alkynyl, benzotriazine, and haloalkyl groups, or combinations thereof. Enhanced adhesion to a variety of substrates can be obtained.

[0185] Alternatively, the porous polysiloxane film may have a hardness of 0.05 GPa or higher, preferably 0.3 GPa or higher, and even more preferably 2.5 GPa or higher, as measured by nanoindentation. The hardness of the porous polysiloxane film can be further increased by a combination of thermosetting and UV curing steps.

[0186] Alternatively, the porous polysiloxane film may have a thermal expansion constant (CTE) of 200 ppm or lower, preferably 100 ppm or lower, more preferably 50 ppm or lower. A low CTE (e.g., 200 ppm or lower, 100 ppm or lower, or 50 ppm or lower) is beneficial in preventing substrate bending during the manufacturing process.

[0187] According to a fifth aspect of the invention, the use of porous polysiloxane films as defined in this disclosure in photolithography methods is provided.

[0188] Alternatively, the porous polysiloxane film defined in this invention may be used as a resist underlayer in a photolithography method, preferably in a method for fabricating semiconductor devices.

[0189] According to a sixth aspect of the present invention, a semiconductor device is provided, comprising a porous polysiloxane membrane as defined in the present invention or a porous polysiloxane membrane obtainable by a method defined in the present invention.

[0190] Alternatively, the semiconductor device may include a porous polysiloxane film as defined in this invention; and a substrate, preferably a semiconductor substrate.

[0191] According to a seventh aspect of the invention, there is provided the use of the composition defined in the invention in the preparation of an antireflective coating film in a photoconductive optical device, a dielectric stack, a resonator structure, an OLED device, an LED device or other optical instrument, or in the preparation of an antireflective coating film for nanoparticles or phosphor particles, or in a method of preparing a semiconductor device.

[0192] According to an eighth aspect of the invention, a film as defined herein is provided for use as a low-dielectric film in a semiconductor device, or in combination with a capping layer as a low-dielectric film or a low-refractive-index film. The term "low-dielectric film" refers to a film having a small relative permittivity κ relative to silicon dioxide, i.e., 3.5κ or less, preferably 3.0κ or less. The term "low-refractive-index film" refers to a film having a low refractive index, i.e., RI of 1.4 or less, preferably 1.3 or less.

[0193] According to a ninth aspect of the present invention, a method for fabricating a semiconductor device is provided, wherein the method comprises:

[0194] - Provide compositions as defined in this disclosure;

[0195] - The composition is applied to a substrate to form a polysiloxane layer on the substrate;

[0196] - Heating the formed polysiloxane layer to cure the polysiloxane;

[0197] - At least partially remove the compound of formula (II) to form a porous polysiloxane film on the substrate;

[0198] - The composition for the resist film is coated onto the porous polysiloxane film to form a resist film on the porous polysiloxane film;

[0199] - Irradiate the resist film with light along a predetermined pattern to form an irradiated structure of the resist film having irradiated resist film areas and unirradiated resist film areas;

[0200] - Develop the irradiation structure of the resist film to form a resist film with a resist pattern;

[0201] - The porous polysiloxane film is etched using the resist pattern of the resist film; and

[0202] - The semiconductor substrate is fabricated using the patterned resist film and the patterned porous polysiloxane film.

[0203] Alternatively, porous polysiloxane membranes can be used as the underlying layer of the resist.

[0204] Alternatively, the irradiated structure of the resist film is developed to remove most of the unirradiated resist film, thereby forming a resist film with a resist pattern.

[0205] Alternatively, the method for preparing the porous polysiloxane film disclosed in this disclosure is a method for preparing a semiconductor device, wherein the substrate optionally includes one or more photoresist underlayer films or one or more organic underlayer films on the top of the substrate; applying the composition to the substrate involves applying the composition to one or more photoresist underlayer films or one or more organic underlayer films of the substrate, thereby forming a polysiloxane layer on one or more photoresist underlayer films or one or more organic underlayer films of the substrate; wherein the method further includes:

[0206] - Perform irradiation, development and / or etching or any combination thereof once or multiple times, preferably irradiation, development and etching once or multiple times.

[0207] Alternatively, the method for preparing the porous polysiloxane film disclosed herein is a method for preparing a semiconductor device, wherein the formed porous polysiloxane film is a photoresist underlayer film or a photoresist film, and the substrate optionally includes one or more photoresist underlayer films or one or more organic underlayer films above the substrate; applying the composition to the substrate involves applying the composition to one or more photoresist underlayer films or one or more organic underlayer films of the substrate, thereby forming a polysiloxane layer on one or more photoresist underlayer films or one or more organic underlayer films of the substrate; wherein the method further includes:

[0208] - Perform irradiation, development and / or etching or any combination thereof once or multiple times, preferably irradiation, development and etching once or multiple times.

[0209] The silicon content of porous polysiloxane membranes is typically at least 20%, at least 30%, especially 35 wt% or higher, and can even reach ~52 wt%.

[0210] Specific examples of prepolymers include, but are not limited to, tetramethoxysilane, tetrachlorosilane, tetraacetoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, methyltriphenoxysilane, methyltribenzyloxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, phenyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and β-cyanoethyltriethoxysilane. Silane, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, dipropyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptomethyldiethoxysilane, epoxypropoxymethyltrimethoxysilane, epoxypropoxymethyltriethoxysilane, α-epoxypropoxyethyltrimethoxysilane, α-epoxypropoxyethyltriethoxysilane, β-epoxypropoxyethyltrimethoxysilane, β-epoxypropoxyethyltriethoxysilane, α-epoxypropoxypropyltrimethoxysilane, α-epoxypropoxypropyltriethoxysilane γ-glycidyl silane, β-glycidyl propyltrimethoxysilane, β-glycidyl propyltriethoxysilane, γ-glycidyl propyltrimethoxysilane, γ-glycidyl propyltriethoxysilane, γ-glycidyl propyltripropoxysilane, γ-glycidyl propyltributoxysilane, γ-glycidyl propyltriphenoxysilane, α-glycidyl butyltrimethoxysilane, α-glycidyl butyltriethoxysilane, β-glycidyl butyltriethoxysilane, γ-glycidyl butyltrimethoxysilane, γ-glycidyl butyltriethoxysilane, δ-glycidyl butyltrimethoxysilane, δ-glycidyl butyltriethoxysilane β-(3,4-epoxycyclohexyl)methyltrimethoxysilane, β-(3,4-epoxycyclohexyl)methyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltripropoxysilane, β-(3,4-epoxycyclohexyl)ethyltributoxysilane, β-(3,4-epoxycyclohexyl)ethyltriphenoxysilane, γ-(3,4-epoxycyclohexyl)propyltrimethoxysilane, γ-(3,4-epoxycyclohexyl)propyltriethoxysilane, δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane, δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane, δ-(3,4-epoxycyclohexyl)propyltrimethoxysilane, γ-(3,4-epoxycyclohexyl)propyltriethoxysilane, δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane, δ-(3,4-epoxycyclohexyl)propyltrimethoxysilane, γ ...4-Epoxycyclohexyl)butyltriethoxysilane, epoxypropoxymethylmethyldimethoxysilane, epoxypropoxymethylmethyldiethoxysilane, α-epoxypropoxyethylmethyldimethoxysilane, α-epoxypropoxyethylmethyldiethoxysilane, β-epoxypropoxyethylmethyldimethoxysilane, β-epoxypropoxyethylethyldimethoxysilane, α-epoxypropoxypropylmethyldimethoxysilane, α-epoxypropoxypropylmethyldiethoxysilane, β-epoxypropoxypropylmethyldimethoxysilane, β-epoxypropoxypropylethyl Dimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, phenylsulfonylaminopropyltriethoxysilane.

[0211] Specific examples of prepolymers are vinyltrimethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, dimethylvinylmethoxysilane, allyltrimethoxysilane, allyltrichlorosilane, allyltriacetoxysilane, allyltriethoxysilane, allylmethyldimethoxysilane, allylmethyldiethoxysilane, 3-butenyltrimethoxysilane, styrylethyltriethoxysilane, styrylethyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropylmethyldimethoxysilane. γ-Methacryloxypropylmethyldiethoxysilane, (methacryloxymethyl)methyldiethoxysilane, (methacryloxymethyl)methyldimethoxysilane, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxypropyltrichlorosilane, methacryloxypropyltriethoxysilane, methacryloxypropyltriisopropoxysilane, 3-acryloxypropyltrimethoxysilane, acryloxymethyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane 3-Acryloyloxypropyldimethylmethoxysilane, 3-Acryloyloxypropyldimethylethoxysilane, Acryloyloxypropyltriethoxysilane, Acryloyloxypropyltriethoxysilane, Acryloyloxypropyltrichlorosilane, (Acryloyloxymethyl(phenylethyl)trimethoxysilane, Methacryloxypropyltriethoxysilane, Methacryloxypropyltrichlorosilane, [2-(3-cyclohexenyl)ethyl]trimethoxysilane, [2-(3-cyclohexenyl)ethyl]triethoxysilane, [2-(3-cyclohexenyl)ethyl]trichlorosilane, [2-(3-cyclohexenyl)ethyl]methyldimethoxysilane, [2-(3-cyclohexenyl)ethyl]methyldimethoxysilane, [2-(3-cyclohexenyl)ethyl]methyldimethoxysilane, [2-(3-cyclohexenyl)ethyl]trichlorosilane [Ethyl]methyldichlorosilane, (5-bicyclo[2.2.1]hept-2-enyl)triethoxysilane, (5-bicyclo[2.2.1]hept-2-enyl)trimethoxysilane, (5-bicyclo[2.2.1]hept-2-enyl)methyldiethoxysilane, (5-bicyclo[2.2.1]hept-2-enyl)ethyldiethoxysilane, (5-bicyclo[2.2.1]hept-2-enyl)dimethylmethoxysilane, (5-bicyclo[2.2.1]hept-2-enyl)trichlorosilane, (5-bicyclo[2.2.1]hept-2-enyl)methyldichlorosilane, (5-bicyclo[2.2.1]hept-2-enyl)dimethylchlorosilane.

[0212] Another specific example of a prepolymer is chloromethyltrimethoxysilane, chloromethylmethyldichlorosilane, chloromethylmethyldimethoxysilane, chloromethyltrichlorosilane, chloromethyltriethoxysilane, 2-chloroethylmethyldimethoxysilane, 2-chloroethylmethyldichlorosilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltrichlorosilane, 2-chloroethyltrichlorosilane, 2-chloroethylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropyltriacetoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3 -Chloropropylmethyldiethoxysilane, bis(chloromethyl)dichlorosilane, bis(chloromethyl)methylchlorosilane, bis(chloromethyl)dimethoxysilane, bis(chloromethyl)methylmethoxysilane, bis(chloromethyl)diethoxysilane, bis(chloromethyl)methylethoxysilane, bis(3-chloropropyl)dichlorosilane, chlorophenylmethyldimethoxysilane, chlorophenyltrimethoxysilane, chlorophenyltriethoxysilane, chlorophenyltrichlorosilane, ((chloromethyl)phenylethyl)methyldimethoxysilane, ((chloromethyl)phenylethyl)trimethoxysilane, and similar compounds wherein the chlorine group is substituted by an equivalent bromine or iodine compound. Specific examples other than those listed above include: 4-bromobutyltrimethoxysilane, 4-bromobutyltrichlorosilane, 2-bromoethyltrimethoxysilane, 5-bromopentyltrimethoxysilane, and bromophenyltrimethoxysilane. Examples of precursors (V) also include linear, branched, cyclic, and aromatic and alkyl aromatic compounds in which multiple hydrogen atoms are replaced by halogen atoms.

[0213] Specific examples of these include trifluoropropyltrimethoxysilane, trifluoropropylmethyldimethoxysilane, trifluoropropyltriethoxysilane, nonafluorohexyltrimethoxysilane, nonafluorohexylmethyldimethoxysilane, 1,2-dibromoethyltrimethoxysilane, 1,2-dibromoethyltrichlorosilane, pentafluorophenyltrimethoxysilane, pentafluorophenyltriethoxysilane, pentafluorophenyltrichlorosilane, bis(pentafluorophenyl)dimethoxysilane, and 4-bromo-3,3,4,4-tetrafluorobutyltrimethoxysilane.

[0214] Other specific examples of prepolymers are 3,3,3-trifluoropropyltrimethoxysilane, 4-acetoxyphenethyltrimethoxysilane, 4-acetoxyphenethyltriethoxysilane, 4-(acetoxyphenethyl)methyldichlorosilane, 4-(acetoxyphenethyl)methyldimethoxysilane, 4-(acetoxyphenethyl)methyldiethoxysilane, 2-(methyl ester)ethyltrimethoxysilane, 2-(methyl ester)ethylmethyldimethoxysilane, 2-(methyl ester)ethyltrichlorosilane, and 2-(methyl ester)ethylmethyldichlorosilane. Alkane, triethoxysilylpropylcarbamate, triethoxysilylpropylmaleamic acid, N-(3-triethoxysilylpropyl)-4-hydroxybutyramide, N-(3-triethoxysilylpropyl)glucamide, (3-triethoxysilyl)propylsuccinic anhydride, ureopropyltriethoxysilane, ureopropyltrimethoxysilane, 3-hydroxy-3,3-bis(trifluoromethyl)propyltriethoxysilane, 4-(methoxymethoxy)trimethoxysilylbenzene, and 6-(methoxymethoxy)-2-(trimethoxysilyl)naphthalene.

[0215] Alternatively, hydrolysis and polymerization can be carried out entirely without solvent, or in one or more solvents, such as alcohols, esters, ketones, and ethers. Specifically, suitable solvents include acetone, ethyl methyl ketone, methanol, ethanol, isopropanol, butanol, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and tetrahydrofuran. Particularly suitable solvents are ketones and ethers, especially where a stabilizing effect exists during hydrolysis through coordination with silicon atoms. Examples of such solvents are ethyl methyl ketone, methyl tetrahydrofuran methyl ether, and ethyl tetrahydrofuran methyl ether.

[0216] Controlled hydrolysis of the monomer is obtained by adding an acid or base solution with a molar ratio of 0.0001 M to 1 M. Organic or inorganic acids can be used in the synthesis. Inorganic acids can be used, such as nitric acid, sulfuric acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, hydrofluoric acid, boric acid, perchloric acid, carbonic acid, and phosphoric acid. Nitric acid or hydrochloric acid is preferred because of their low boiling points, which simplifies the purification of the product. Alternatively, various organic acids can be used instead of inorganic acids. Organic acids are carboxylic acids, sulfonic acids, alcohols, mercaptoyl groups, enol groups, and phenolic hydroxyl groups. Examples include methanesulfonic acid, acetic acid, ethanesulfonic acid, toluenesulfonic acid, formic acid, or oxalic acid. The base used in the synthesis can also be inorganic or organic. Typical inorganic bases include metal hydroxides, carbonates, bicarbonates, and other salts that produce alkaline aqueous solutions. Examples of such materials are sodium hydroxide, potassium hydroxide, cesium hydroxide, calcium hydroxide, sodium carbonate, and sodium bicarbonate. On the other hand, organic bases include a large class of metal salts of organic acids (e.g., sodium acetate, potassium acetate, sodium acrylate, sodium methacrylate, sodium benzoate), straight-chain, branched or cyclic alkylamines (e.g., diaminoethane, aminoethane, putrescine, cadaverine, triethylamine, butylamine, dibutylamine, tributylamine, piperidine), amidines and guanidines (e.g., 8-diazabicyclo(5.4.0)undec-7-ene, 1,1,3,3-tetramethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene), phosphazenes (e.g., P1-t-Bu, P2-t-Bu, P4-t-Bu), and quaternary ammonium compounds (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide).

[0217] The temperature of the reaction mixture during hydrolysis and condensation can vary between -30 and 170°C. Those skilled in the art know that lower reaction temperatures improve control over the reaction, but at the cost of longer reaction times, while excessively high temperatures may cause the process to proceed too quickly and become uncontrollable. Therefore, a reaction time of 1–48 hours is preferred at a temperature of 0–100°C. More preferably, a reaction time of 2–24 hours is preferred. Using appropriate conditions, the method of the present invention produces partially crosslinked siloxane polymers in an organic solvent system, said polymers having a molecular weight of about 5000 to 100,000 g / mol, particularly about 1,000 to 50000 g / mol, based on polystyrene standards.

[0218] After the composition is applied by spin coating or other suitable deposition methods, a pre-baking step can be applied to remove solvents and volatile compounds contained in the composition (coating material). This helps to avoid contamination in the manufacturing equipment. Pre-baking can be performed at different temperatures and times, depending on the boiling points of the compounds of formula (II), solvents, and volatile components. Typically, pre-baking can be performed at 60–120°C for 30 seconds to no more than 30 minutes.

[0219] The irradiated film (e.g., a resist film) can be created by exposing the film to EUV light, an electron beam, or a similar exposure method using an optional mask. Patterning can then be formed on the substrate. The dose required to form the pattern is at least 10 mJ / cm². 2 The maximum value is 200 mJ / cm 2 .

[0220] Optionally, post-exposure baking can be performed after irradiation of the film. This step can improve cross-linking in the exposed areas, resulting in higher resist contrast. Post-exposure baking can be performed at a temperature of 80°C to no more than 150°C for a duration of 30 seconds to no more than 30 minutes.

[0221] Development can be performed to remove unexposed areas, thereby obtaining the designed pattern. During the development step, the unexposed areas of the photoresist dissolve in the developer. Any suitable developer can be used, without limitation to any specific developer. Examples of developers include, but are not limited to, tetramethylammonium hydroxide, such as tetramethylammonium hydroxide at a concentration of 2–3 wt% in water or methanol.

[0222] The following non-limiting examples illustrate the embodiments.

[0223] Example

[0224] method

[0225] The molecular weight averages (Mz, Mw, and Mn), molecular weight distribution (MWD), and their width were determined by gel permeation chromatography (GPC), described by the polydispersity index PDI = Mw / Mn (where Mn is the number-average molecular weight and Mw is the weight-average molecular weight). A GPC instrument equipped with an Agilent Technologies differential refractometer (RI) and three Shodex KF separation columns (KF-801, KF-802, KF-803L) and a Shodex KF-G 4A guard column was used. Tetrahydrofuran (THF) was used as both solvent and mobile phase. The chromatographic system was run at a constant flow rate of 1 mL / min at 40 °C. 200 μL of sample solution was injected for each analysis. The column set was calibrated using 12 narrow molecular weight distribution polystyrene (PS) standards, ranging from 0.16 kg / mol to 50.0 kg / mol. The PS standards were dissolved at room temperature for several hours. Third-order polynomial fitting was used to fit the calibration data. All samples were prepared at concentrations ranging from 0.5 to 1 mg / mL, dissolved in THF at 20°C for 5 minutes with gentle shaking, and then filtered through a 0.22 μm nylon filter.

[0226] Post-coating delay (PCD) testing: The polymer solution in the example was diluted to a 6.5% solution with PGMEA and then filtered through a 0.22 μm nylon filter. Film samples were prepared by spin-coating the polymer solution onto a 4-inch silicon wafer at 1500 rpm for 20 seconds. Then, a soft bake was performed at 250°C for 90 seconds under N2. Film thickness was measured using a JAWoollam M2000D-ESM-200AXY spectroellipsometry.

[0227] Thermogravimetric analysis (TGA) for testing was performed using a NETZSCH TG 209F3 Tarsus. The powder obtained after removing the coating film from the wafer was tested using the TGA apparatus. The following conditions were used: N2 flow rate of 20 mL / min, temperature increased from 30°C to 600°C at a heating rate of 10°C / min. The temperature at which 5% heat loss occurred was recorded as the heat resistance value. The higher the temperature at which 5% heat loss occurs, the better the heat resistance of the coating film.

[0228] The refractive index (n) and extinction coefficient (k) of a 180 nm thick polymer film sample were determined using a JAWoollam M2000D-ESM-200AXY spectroellipsometry. The ellipsometry scanned the film at wavelengths from 193 nm to 1000 nm, and then the optical parameters were varied according to the wavelength modulation curves.

[0229] Exhaust test: using PZ 1 The 4ET heating plate heats the wafer coated with the test material to 250°C, and the material exhaust is measured using an electrochemical quartz crystal microbalance Gamry eQCM 10M.

[0230] The etching rate of the polymer was measured using an Oxford RIE Plasmalab 80Plus. The cured film was etched for 30 seconds under oxygen plasma (O2 / 5 sccm, Ar / 20 sccm) at 30 mTorr. The film thickness before and after etching was measured. The difference divided by the etching time gave the etching rate (in nm / min).

[0231] Gel permeation chromatography data were collected on an Agilent 1260 Infinity LC system equipped with tandem Shodex KF columns (KF-G; KF-803L; KF-802; KF-801). The detector and column temperature were maintained at 40 °C. The THF eluent flow rate was 1.0 mL / min.

[0232] Electron beam lithography was performed on Vistec equipment. The solids content of the formulation was 1.3%. The formulation was spin-coated onto a silicon wafer using a spin coater at 1500 rpm for 30 seconds. A soft bake at 80°C was then performed for 1 minute. Electron beam doses ranged from 100 to 900 μC / cm² at 100 kV and 1 nA. The development step involved immersing the film in a 2.38% TMAH solution for 1 minute. The film was then rinsed three times with deionized water and finally dried with nitrogen.

[0233] EUV lithography: A polymer formulation with a 1.3% solids content was spin-coated onto a silicon wafer at 1500 rpm for 30 seconds. It was then soft-baked on a hot plate at 80°C for 1 minute. The soft-baked film sample was then irradiated using the XIL-II EUV tool at the Paul Scherrer Institute in Feligen, Switzerland. The dose ranged from 2 to 150 mJ / cm². 2 No. The development step involves immersing the membrane in a 2.38% TMAH solution for 1 minute. Then, the membrane is repeatedly washed three times with deionized water and finally dried with nitrogen.

[0234] Citrate ester 1, Example 1: Synthesis of citrate esters containing tert-butoxyethyl groups

[0235] 320 g of tert-butoxyethanol, 250 g of triethyl citrate, and 100 g of heptane were combined with the transesterification catalyst ZnTAC24. TM (10 g of oxo[hexa(trifluoroacetic acid)]tetrazinc and its trifluoroacetic acid adduct (containing up to 7% toluene)) was placed together in a 1 L rb flask. A short-path distillation head was connected, and the system was heated at 110–130 °C for 5 days. While collecting the heptane-ethanol azeotrope, small portions of fresh heptane were added until no ethanol was observed in the distillate by GC. The product was distilled at 210–230 °C / 0.1 mbar to give 476 g of product. The distillate, consisting of 75% tris(tert-butoxyethyl) citrate and 25% ethyl-bis(tert-butoxyethyl) citrate, was analyzed by GC / MS.

[0236] Citrate ester 2, Example 2: Synthesis of tris(methoxybutyl)citrate

[0237] 160 g of 3-methoxybutanol, 74 g of citric acid, and 50 g of toluene, along with 0.1 g of pentafluoroaniline trifluoromethanesulfonate as the esterification catalyst, were placed in a 500 mL rb flask. A Dean-Stark apparatus was connected, and the system was heated to 110–150 °C until all condensate had drained (4 hours). The product was distilled at 200 °C / 0.1 mbar to give 104 g of product. The distillate tris(3'-methoxybutyl)citrate was determined to be 99.5% pure by GC / MS.

[0238] Citrate ester 3, Example 3: Synthesis of tetrahydrofurfuryl citrate esters

[0239] Trimethyl citrate (40g), tetrahydrofurfuryl alcohol (70g), and ZnTAC24 were added. TM (3g) and toluene (50g) were placed in a 250mL RB flask and heated at 110–130°C for three days, while collecting the toluene-methanol azeotrope. After the third day, the solution contained a mixed solution of dimethyltetrahydrofurfuryl citrate, methyl ditetrahydrofurfuryl citrate, and tritetrahydrofurfuryl citrate isomers. Toluene and excess tetrahydrofurfuryl alcohol were evaporated at 110°C / 5mbar, the catalyst was removed using a 0.1μm PTFE filter, and the product containing the mixed tetrahydrofurfuryl citrate was distilled at 180–240°C. GC / MS analysis showed that it contained 28% tritetrahydrofurfuryl citrate, 55% methyl ditetrahydrofurfuryl citrate, and 17% dimethyltetrahydrofurfuryl citrate.

[0240] Polymer 4, Example 4:

[0241] In the presence of 100 g of 0.01 mol HNO3 aqueous solution, methyltriethoxysilane (100 g) and tetraethoxysilane (117 g) were refluxed in 200 mL of acetone for 3 hours to prepare a polymethylsiloxane dielectric material. After the reaction, the polymer was further diluted with n-butanol to obtain a 7 wt% polymer solution (master batch 4, MB4). After spin-coating the MB4 film onto a silicon wafer at 300 °C for 15 minutes, the film refractive index was 1.42.

[0242] Polymer 5, Example 5:

[0243] The alkyl-bridged disilly monomer 1,1,1,4,4-dimethoxy-1,4-disilpentane (100 g) was hydrolyzed and polymerized in reflux acetone (300 g) with 3 equivalents of 0.01 M HCl for 5 hours. The resulting polymer was solvent-exchanged with PGMEA to obtain a 10 wt% solution of masterbatch 5 (MB5).

[0244] Polymer 6, Example 6:

[0245] (3-glycidoxypropyl)trimethoxysilane (30 g) and tetraethoxysilane (10 g) were hydrolyzed in 0.01 M HCl (10 g) in acetone (25 g) for 4 hours, and then the solvent was exchanged for PnP. Thus, a 38 wt% polymer solution (MB6) was obtained.

[0246] Polymer 7, Example 7:

[0247] Diallyl (triethoxysilylpropyl) isocyanurate (20 g) and tetraethoxysilane (10 g) were hydrolyzed in 0.01 M HCl (10 g) and acetone (25 g) for 3 hours. The polymer solution was then solvent-exchanged to PnP to obtain masterbatch 7 (MB7) with a solid content of 33 wt%.

[0248] Polymer 8, Example 8:

[0249] According to Example 1 of EP3597710A1, a low-refractive-index tetramethylammonium hydroxide catalyzed porous polymer was prepared as an 8 wt% solution (MB8) in MIBK using tetraethoxysilane (130 g) and methyltriethoxysilane (110 g). After curing the film obtained from MB8 at 200 °C for 5 minutes, a film RI of 1.25 was obtained.

[0250] Polymer 9, Example 9:

[0251] The polymerization of Example 8 was repeated using a different monomer composition: 110 g of tetraethoxysilane and 130 g of methyltriethoxysilane, along with 5 g of the cyclic silane monomer 1,1,3,3,5,5-hexaethoxy-1,3,5-trisilylonhexane (from Gelest, Inc.). Following polymerization and solvent exchange, a 10 wt% polymer solution (MB9) in MIBK was obtained. The resulting film from MB9, after curing at 200 °C for 5 minutes, had a refractive index of 1.29 at 632 nm.

[0252] Catalyst 10, Example 10:

[0253] The tetramethylguanidine-based curing catalyst is prepared by mixing tetramethylguanidinepropyltrimethoxysilane (CFS-S019 from Cfmat.com) and pentafluorobenzoic acid at a ratio of 1:1.5 mol and diluting it in isopropanol to a 10% (w / w) solution.

[0254] Comparative porogen 11, comparative example 11

[0255] According to Example 2 of U.S. Patent Application 20210301136, a branched hydroxyalkylsiloxane porogen (1-(3′-hydroxy-3′,7′,11′,15′-tetramethylhexadecyl)-1,1,3,3,3-pentamethyldisiloxane (“iPhPMDS”)) is prepared by hydrogenation silanization.

[0256] Comparison of low-refractive-index films on microlenses, Example 12

[0257] The MB4 fraction (base film RI 1.42) in Example 4 and the citrate ester (300 wt% solids based on polymer solution) and 0.1 wt% fluoroalkyl surfactant (3M FC-4432) in Example 3 TM ) and 2 wt% light alkali generator (PBG, WPBG-345) TM The film was prepared using Fujifilm's biguanide PBG. It was spin-coated onto a silicon wafer and onto soda-lime glass, followed by UV exposure (140 mJ / cm²). 2 The film was cured at 230°C / 5 min + 250°C / 10 min (refractive index 248 nm). A transparent, colorless, and hazy film with an RI of 1.23 at a refractive index of 632 nm was obtained. This example demonstrates that the citrate composition of this disclosure is highly compatible with spin-coated glass-type polymethylsiloxane materials and also effectively reduces their film RI.

[0258] In contrast, when MB4 was treated similarly with the pore-forming agent in Comparative Example 11, it was spin-coated onto a substrate (soda-lime glass), exposed to ultraviolet light, and cured as described above, forming a milky white film. Due to the poor quality of this film, its refractive index (RI) could not be measured by elliptic polarization.

[0259] This comparison demonstrates enhanced compatibility between the compound (porogen) of the present invention and the methylsiloxane polymer of Example 4, in contrast to the opposite of the comparative porogen of Example 11.

[0260] Comparison of pore-forming agents, Example 13

[0261] The MB5 fraction from Example 5 was formulated into a product with a solids weight of 3 times, containing tetrahydrofurfuryl mixed citrate (from Example 3), 0.1 wt% fluorosurfactant FC-4432, and 0.4 wt% (Z)-{[bis(dimethylamino)methylene]amino}-N-cyclohexyl(cyclohexylamino)methylimine tetra(3-fluorophenyl)boronate (WPBG-345), based on the total weight of the formulation. The film was spin-coated onto a silicon wafer and soda-lime glass, and then exposed (140 mJ / cm). 2 The film was cured at 230°C for 5 minutes followed by 250°C for 10 minutes (632 nm). A transparent, colorless, and hazy film with an RI of 1.39 was obtained at 632 nm. In contrast, the refractive index of the parent polymer solution (MB5 in Example 5) was 1.45 at 632 nm. This example demonstrates that the invention is also applicable to polymers made from alkyl-bridged disilicide monomers.

[0262] In contrast, when MB5 was treated similarly with the porogen in Comparative Example 10, a milky white film was formed, and its RI could not be measured by ellipsometer due to the poor film quality.

[0263] This comparison shows that, compared with the comparative porogen in Example 11, the polymer made from alkyl-bridged disilane monomers has improved compatibility with the compounds of the present invention as porogens.

[0264] Comparison of low refractive index formulations, Example 14

[0265] Masterbatch MB8 was prepared according to EP3597710A1. MB8 was mixed with MB6 from Example 6 at a polymer-polymer ratio of 10:2. The film refractive index of the mixture after curing at 200°C for 5 minutes was found to be 1.32, higher than the target RI < 1.25. When the mixture was mixed with the citrate mixture obtained in Example 1 at a ratio of 10:11, the film refractive index decreased to 1.24, which is an acceptable refractive index. The solution was spin-coated onto a polymethacrylate-based CMOS microlens array and cured at 200°C for 5 minutes. The film exhibited good adhesion as tested with transparent tape. Figure 1 ). Figure 1 The image shows that the adhesive on the transparent tape is visible, but the low-refractive-index film remains attached underneath. Scanning electron microscopy reveals no delamination between the low-refractive-index film and the microlens array. Figure 2 ).

[0266] Similarly, a mixture of MB9 from Example 9, MB7 from Example 7, and the citrate mixture obtained in Example 1 was prepared at a mass ratio of 4:1:5.5. The cured film had a refractive index of 1.233 and exhibited excellent adhesion on the CMOS microlens array.

[0267] In contrast, masterbatch MB8 was diluted with methyl isobutyl ketone to obtain a 6.5 wt% polymer solution and used as is. The solution was spin-coated onto the same polymethacrylate-based microlens array and cured at 200°C for 5 minutes to form a low-refractive-index film. Although the film's refractive index reached the target value of 1.25, the film failed the transparent tape test. Figure 3 (Top left corner) Figure 3 Optical microscope images are shown, indicating delamination after tape testing on a microlens array spin-coated with a 6.5 wt% polymer solution. Furthermore, Figure 4 Layering between the low-refractive-index film and the microlens array was observed under an electron microscope.

[0268] In another comparison, it was found that the porogen in Comparative Example 11 was incompatible with the adhesion-improving polymers in Examples 6 (MB6) and 7 (MB7). Each combination produced a blurry white film, making the film unsuitable for optical applications.

[0269] Comparison of low-refractive-index films on deep trench microstructures. Example 15.

[0270] The citrate pore-forming agent from Example 2 was mixed with MB5 from Example 5 and MB9 from Example 9 at a mass ratio of 6:1:1. The curing catalyst from Example 9 (1% w / w) and 0.2 wt% of a silicone-based surfactant (polyether-modified polydimethylsiloxane) BYK-333 (BYK GmbH) were added, and the solution was diluted to 7 wt% with propylene glycol n-propyl ether. This formulation was spin-coated onto a polymethacrylate-based microlens array, and the resulting film was cured at 200 °C for 10 minutes. The cured film was found to have a low refractive index of 1.24. The formulation was also spin-coated onto a patterned Si wafer with lines (height 230 nm, width 85 nm, spacing 40 nm) and cured at 200 °C for 10 minutes. Electron microscopy images showed perfect gap filling with no voids. Figure 5 ).

[0271] In contrast, the low-refractive-index masterbatch MB8 prepared according to EP3597710A1 was diluted with methyl isobutyl ketone to obtain a 6.5 wt% polymer solution, which was used as is. When this material was spin-coated onto the same narrow trench structure of a patterned Si wafer with lines (height 230 nm, width 85 nm, spacing 40 nm) and baked at 200 °C for 10 minutes, SEM images showed large voids, indicating that the material could not fill the gaps in the narrow-spacing pattern. Figure 6 ).

[0272] Further comparison revealed that the pore-forming agent in Comparative Example 11 was incompatible with the mixture of MB8 and the polymer (MB5) of Example 5, resulting in a fogged white film that was unsuitable for optical applications in trench structures.

[0273] Effect of citrate addition on membrane RI, Example 16

[0274] The porogen (citric acid ester mixture) from Example 1 was mixed with different amounts of the polymer (RI = 1.29) from Example 9 and 0.1 wt% of the curing catalyst from Example 9. The membrane was cured at 250 °C. The effect of the amount added on the membrane RI was measured and plotted. Figure 7 As can be seen, by adding citrate ester at four times the mass of the matrix polymer, the RI of the film decreased from 1.29 to 1.14. When 500% of the sample was cured at 800°C for 1 minute, the RI could be further reduced to 1.128.

[0275] Although exemplary embodiments of this disclosure have been described herein, it should be noted that various changes and modifications may be made to the embodiments of this disclosure without departing from the legal protection scope defined by the appended claims. In the appended claims, the word "comprising" does not exclude other elements, steps, or operations, and the indefinite articles "a" or "an" do not exclude multiple. The fact that certain measures are defined in mutually different dependent claims does not indicate that combinations of these measures cannot be fully utilized.

Claims

1. A composition comprising a polysiloxane and a compound of formula (II): in R 1 R 2 and R 3 Each is independently selected from H, and linear, saturated, unsaturated or aromatic, branched or cyclic C. 1-15 - A hydrocarbon group, which optionally includes 1-4 heteroatoms, each heteroatom independently selected from oxygen, sulfur, nitrogen, and phosphorus; the condition is R 1 R 2 and R 3 At least one of them is selected from linear, saturated, unsaturated or aromatic, branched or cyclic C 1-15 - A hydrocarbon group, which optionally includes 1 to 4 heteroatoms, each heteroatom being independently selected from oxygen, sulfur, nitrogen and phosphorus; R 4 Selected from hydrogen, C 1-10 -acyl group, and linear, saturated or unsaturated, branched or cyclic C 1-10 - A hydrocarbon group, which optionally includes 1 to 4 heteroatoms, each heteroatom being independently selected from oxygen, nitrogen, phosphorus and sulfur.

2. The composition according to claim 1, wherein, Based on 10 parts by weight of the polysiloxane, the composition comprises 3–150 parts by weight, particularly 5–100 parts by weight, for example 5–80 parts by weight of the compound of formula (II).

3. The composition according to any one of the preceding claims, wherein, The compound of formula (II) has a boiling point of at least 70°C at a pressure of 1 mbar.

4. The composition according to any one of the preceding claims, wherein, The polysiloxane is a polymer with an average molecular weight (Mw) of 500–1,500,000 g / mol, particularly 1,000–100,000 g / mol.

5. The composition according to any one of the preceding claims, wherein, The polysiloxane is a polysiloxane of one or more silane monomers, each of which is independently selected from the group consisting of silane monomers having the formulas (IVa), (IVb), (IVc), (IVd), and (IVe). as well as in Z 1 Z 2 Z 3 Z 4 Z 5 Z 6 Z 7 and Z 8 Each is independently selected from hydrolyzable and non-hydrolyzable groups, but Z 1 Z 2 Z 3 Z 4 Z 5 Z 6 Z 7 and Z 8 At least one of them is a hydrolyzable group; Each hydrolyzable group is independently selected from C 1-15 -alkoxy groups, halogens and C 1-15 The group composed of -carboxylate groups; Each non-hydrolyzable group is independently selected from straight-chain, saturated, unsaturated, or aromatic, branched, or cyclic C groups. 1-20 - A hydrocarbon group, optionally comprising 1–4 heteroatoms, each heteroatom independently selected from oxygen, silicon, nitrogen, sulfur, and phosphorus, and optionally substituted by 1–4 substituents, each substituent independently selected from halogen, OH, isopropenyl carbonyloxy, vinyl carbonyloxy, (ethylene oxide-2-yl)methoxy, SH, N(CH3)2, 2-aminoethylamino, C 2-10 -alkyl, 7-oxabicyclo[4.1.0]hept-3-yl, C 2-10 -Alkenyl and C 6-10 -Aryl; Each R 5 Independently selected from CH2 and CH2CH2; Each R 6 Independently selected from CH2 and O; R 7 Independently selected from (CH2) n O, where n is an integer selected from 1 to 10.

6. The composition according to claim 5, wherein, Each non-hydrolyzable group is selected from C 2-10 -Alkenyl, C 2-10 -Alynyl group, C 5-10 -Aryl and straight-chain, branched or cyclic C 1-20 -alkyl group, which optionally contains 1-4 heteroatoms, each heteroatom being independently selected from the group consisting of oxygen, silicon, nitrogen, sulfur and phosphorus.

7. The composition according to claim 5 or 6, wherein, Each non-hydrolyzable group is selected from methyl, ethyl, propyl, vinyl, phenyl, benzyl, dimethylphenyl, trimethylphenyl, tetramethylphenyl, naphthyl, diethylphenyl, mercaptopropyl, chloromethyl, 3-[2,4,6-trioxo-3,5-bis(prop-2-enyl)-1,3,5-triazin-1-yl]propyl, methacryloyloxypropyl, epoxypropoxypropyl, 3,4-epoxy-cyclohexylethyl, dimethylaminopropyl, and aminoethylaminopropyl.

8. The composition according to any one of the preceding claims, wherein, The composition further comprises a solvent, preferably in an amount of 1-99.9 wt% based on the total weight of the composition, more preferably 5-99 wt%.

9. The composition according to claim 8, wherein, The solvent is selected from C. 1-15 Alkanes, C 2-15 Ester, C 3-15 Ketones, C 2-15 Ethers and C 1-15 Alcohol, preferably, the solvent is propylene glycol n-propyl ether (PnP).

10. The composition according to any one of the preceding claims, wherein, The composition further comprises one or more curing catalysts, preferably in an amount of 0.001-10 wt% based on the total weight of the composition.

11. The composition according to claim 10, wherein, The one or more curing catalysts are each independently selected from the group consisting of thermally induced radical catalysts, photo-induced radical catalysts, tin-containing catalysts, platinum-containing catalysts, basic catalysts, basic release catalysts, acidic catalysts, thermally or photo-released acidic catalysts, and fluoride ion release catalysts.

12. The composition according to any one of the preceding claims, wherein, At a pressure of 1 mbar, the temperature difference between the boiling point of the compound of formula (II) and the curing temperature of the polysiloxane is 100°C or less, preferably 50°C or less.

13. The composition according to any one of the preceding claims, wherein, The composition also includes surfactants and / or toughening agents.

14. A method for preparing a composition according to any one of the preceding claims, wherein, The preparation method includes: - Provide polysiloxanes or mixtures of polysiloxanes, and - The composition is formed by mixing a polysiloxane or a mixture of polysiloxanes with a compound of formula (II).

15. The method for preparing the composition according to claim 14, wherein, The polysiloxane or a mixture of the polysiloxanes is provided in a solvent; or the polysiloxane or a mixture of the polysiloxanes is mixed with a compound of formula (II) in a solvent.

16. A method for preparing a porous polysiloxane membrane, wherein, The method includes: - Provide a composition as described in any one of claims 1-13; - The composition is applied to a substrate to form a polysiloxane layer on the substrate; - Heating the formed polysiloxane layer to cure the polysiloxane; and -At least partially remove the compound of formula (II), - thereby forming the porous polysiloxane film on the substrate.

17. The method for preparing a porous polysiloxane membrane according to claim 16, wherein, The step of heating the polysiloxane layer formed includes heating the polysiloxane layer formed at a temperature selected from 70-250°C.

18. The method for preparing a porous polysiloxane membrane according to any one of claims 16-17, wherein, The steps for heating the polysiloxane layer include: soft baking the polysiloxane layer at 110-120°C for 1-5 minutes, and curing the soft-baked layer at 190-200°C for 1-60 minutes.

19. The method for preparing a porous polysiloxane membrane according to any one of claims 16-18, wherein, Applying the composition to the substrate means spin-coating, spraying, dipping, or inkjet-coating the composition onto the substrate.

20. The method according to any one of claims 16-19 is used to prepare a semiconductor device, wherein, The method includes: - The composition for the resist film is coated onto the porous polysiloxane film to form a resist film on the porous polysiloxane film; - Irradiate the resist film with light along a predetermined pattern to form an irradiated structure of the resist film having irradiated resist film areas and unirradiated resist film areas; - Develop the irradiation structure of the resist film to form a resist film with a resist pattern; - Etching the porous polysiloxane film using the resist pattern of the resist film; and - The semiconductor substrate is fabricated using the resist film patterned in this way and the porous polysiloxane film patterned in this way.

21. The method according to any one of claims 16-20 is used to prepare a semiconductor device, wherein, The formed porous polysiloxane film serves as a photoresist underlayer or as a photoresist film, and the substrate may optionally include one or more photoresist underlayers or one or more organic underlayers located on top of the substrate; The step of applying the composition to a substrate is to apply the composition to one or more photoresist underlayers or one or more organic underlayers of the substrate, thereby forming the polysiloxane layer on the one or more photoresist underlayers or one or more organic underlayers of the substrate; and wherein the method further comprises: - Perform at least one of irradiation, development and / or etching or any combination thereof once or multiple times.

22. A porous polysiloxane membrane, which can be obtained by the method for preparing a porous polysiloxane membrane according to any one of claims 16-21, wherein, The porous polysiloxane membrane comprises polysiloxane.

23. The porous polysiloxane membrane according to claim 22, wherein, The thickness of the porous polysiloxane membrane is at least 10 nm.

24. The porous polysiloxane membrane according to any one of claims 22-23, wherein, The refractive index of the porous polysiloxane film is 1.5 or less, preferably 1.4 or less, and more preferably 1.3 or less.

25. The porous polysiloxane membrane according to any one of claims 22-24, wherein, The porous polysiloxane membrane contains a toughening agent.

26. Use of the porous polysiloxane film according to any one of claims 22-25 in a photolithography method.

27. A semiconductor device comprising a porous polysiloxane membrane according to any one of claims 22-25 or a porous polysiloxane membrane obtainable by any one of claims 16-21.

28. The composition according to any one of claims 1-13 is used in the preparation of an antireflective coating film in a photoconductive optical device, a dielectric stack, a resonator structure, an OLED device, an LED device or other optical instrument, or in the preparation of an antireflective coating film for nanoparticles or phosphor particles, or in a method of preparing a semiconductor device.

29. The use of the porous polysiloxane film according to any one of claims 22-26 as a low-dielectric film in a semiconductor device, or in combination with a capping layer as a low-dielectric film or a low-refractive-index film.

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