Manufacturing method of processed substrate

Abstract

A method for manufacturing a processed substrate with improved flatness is provided. A method for producing an engineered substrate comprising the steps of: (a) applying to a substrate having grooves an amount of a cured film-forming composition sufficient to fill the grooves of the substrate to form a composition layer; (b) removing excess portions of the composition layer by scraping with a separating member to form a substrate surface having improved flatness; and (c) heating the substrate to cure the composition layer from which excess portions have been removed.

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a processed substrate. [Background technology]

[0002] Due to the high integration of electronic devices, particularly semiconductor devices, wiring layers and the like are multi-layered. In order to insulate each layer from the other layers when multi-layering, a liquid composition is applied to form a coating film, which is then cured to form an insulating film. This film is required to be flat in order to undergo further processing. Planarization is performed, for example, by a method such as chemical mechanical polishing (CMP).

[0003] Planarization by CMP may cause differences in planarization characteristics due to hardness or chemical properties, and is inefficient for planarizing thick films. Therefore, a new planarization method has been proposed in which the formed cured film is physically cut to a specified height (for example, Patent Document 1).

[0004] When a coating film is formed by filling a groove with a liquid composition, if the groove has a complex structure or is deep, the coating film formed tends to have low flatness and uneven thickness.If the film thickness is uneven, the film stress becomes uneven during heating for curing, which makes it easy for cracks to occur and makes it difficult to form a dense cured film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent Application Publication No. 2075825 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have recognized that there are one or more problems that still need to be improved in the method of manufacturing a substrate having a cured film with a buried groove. These problems include, for example: The formed cured film has poor flatness; cracks occur; the formed cured film has low density; and the formed cured film cannot be flattened efficiently. [Means for solving the problem]

[0007] The method for producing a processed substrate according to the present invention comprises the following steps. (a) applying to a substrate having grooves an amount of a cured film-forming composition sufficient to fill the grooves of the substrate to form a composition layer; (b) removing excess portions of the composition layer by scraping with a separating member to form a substrate surface with improved planarity; and (c) heating the substrate to harden the composition layer from which the excess portion has been removed;

[0008] A method for producing an element of an electronic device according to the present invention comprises the method described above. Effect of the Invention

[0009] According to the present invention, one or more of the following effects can be achieved. The formed cured film has high flatness; the occurrence of cracks is suppressed; the formed cured film has high density; and the manufacturing process is efficient. [Brief description of the drawings]

[0010] [Figure 1] 1 is a conceptual diagram showing one embodiment of a composition layer before and after excess portions are removed. [Diagram 2] Electron microscope photograph of the composition in a cured state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Definition] In this specification, unless otherwise specifically stated, the definitions and examples set forth in this paragraph shall be followed. The singular includes the plural, and "a" or "the" means "at least one." An element of a concept may be expressed by a plurality of species, and when an amount thereof (e.g., mass % or mole %) is stated, the amount refers to the sum of the plurality of species. "And / or" includes all combinations of the elements as well as its use alone. When a numerical range is indicated using "~" or "-", it includes both endpoints and the units are the same. For example, 5 to 25 mol % means 5 mol % or more and 25 mol % or less. Alkyl means a group obtained by removing one arbitrary hydrogen from a linear, branched or cyclic saturated hydrocarbon, and includes linear alkyl, branched alkyl and cyclic alkyl, and optionally includes a linear or branched alkyl as a side chain in a cyclic structure. Aryl means a group obtained by removing one arbitrary hydrogen from an aromatic hydrocarbon. "C x-y ", "C x ~C y " and "C x " refers to the number of carbons in a molecule or substituent. For example, C 1-6 Alkyl refers to an alkyl chain having from 1 to 6 carbons (methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.). When a polymer has multiple types of repeating units, these repeating units are copolymerized. These copolymerizations may be alternating copolymerization, random copolymerization, block copolymerization, graft copolymerization, or a mixture of these. When polymers or resins are shown by structural formulas, the n or m in parentheses indicates the number of repeats. Temperature is measured in degrees Celsius. For example, 20 degrees means 20 degrees Celsius. The additive refers to a compound having that function (for example, in the case of a base generator, it is a compound that generates a base). The compound may be dissolved or dispersed in a solvent and added to the composition. In one embodiment of the present invention, such a solvent is preferably contained in the composition of the present invention as a solvent or other component.

[0012] Hereinafter, an embodiment of the present invention will be described in detail.

[0013] <Method of manufacturing processed substrate> A method for producing an engineered substrate according to the present invention comprises the following steps. (a) applying to a substrate having grooves an amount of a cured film-forming composition sufficient to fill the grooves of the substrate to form a composition layer; (b) removing excess portions of the composition layer by scraping with a separating member to form a substrate surface with improved planarity; and (c) heating the substrate to harden the composition layer from which the excess portion has been removed;

[0014] Process (a) Step (a) is a step of applying to a substrate having grooves an amount of a cured film-forming composition sufficient to fill the grooves of the substrate, to form a composition layer. In the present invention, the substrate may be a single layer or a laminate. The shape of the groove is not particularly limited, but in the present invention, since it is characterized in that it can easily penetrate into narrow grooves and form a uniform cured film even inside the groove, it is preferable that the substrate has grooves or holes with a high aspect ratio. Here, the shape of the groove is not particularly limited, and the cross section may be any shape such as a rectangle, a forward tapered shape, a reverse tapered shape, a curved shape, etc. In addition, both ends of the groove may be open or closed. Examples of substrates having grooves include substrates for electronic devices equipped with transistor elements, bit lines, capacitors, etc. The manufacture of such electronic devices may include a through-hole formation process for forming holes that vertically penetrate the filling material of the fine grooves, following a process for forming an insulating film called PMD between a transistor element and a bit line, between a transistor element and a capacitor, between a bit line and a capacitor, or between a capacitor and a metal wiring, an insulating film called IMD between a plurality of metal wirings, or filling an isolation groove.

[0015] The cured film-forming composition is applied to a substrate. In the present invention, the cured film-forming composition may be applied directly to the substrate or may be applied to the substrate via one or more intermediate layers. There is no particular limitation on the method for applying the solution to the substrate, and examples of the method include ordinary application methods such as spin coating, dipping, spraying, transfer, and slit coating. A preferred cured film-forming composition will be described later. A composition layer is formed by applying the cured film-forming composition. At this time, a drying step by spin drying, reduced pressure, pre-baking or the like can be carried out as necessary, but preferably does not include a heating step at 150° C. or higher, and more preferably does not include a heating step and a drying step by spin drying is carried out. The amount sufficient to sufficiently fill the grooves of the substrate means that the grooves are filled with the cured film-forming composition and a composition layer is formed even in areas of the substrate surface that do not have grooves.

[0016] Process (b) Step (b) is a step of removing excess portions of the pre-cured composition layer by scraping them off with a separating member to form a substrate surface with improved flatness. In step (b), scraping is performed by pressing and moving the separating member against the substrate. In a preferred embodiment, scraping is performed by moving the separating member parallel to the main plane of the substrate, preferably by rotating the separating member in a horizontal plane while the substrate is stationary. Scraping can also be performed by fixing the separating member and rotating the substrate, or by moving both. It is also possible to use a device for cutting the substrate surface. The separating member has, for example, a blade portion, and the material of the blade portion is not particularly limited as long as it has an appropriate hardness, and stainless steel, resin, etc. can be used. The amount of the excess portion to be scraped off can be adjusted by adjusting the hardness and down force of the blade of the separating member. If a large amount of the composition remains on the substrate surface after scraping, the variation in thickness of the composition layer, i.e., the film thickness difference, tends to increase. Therefore, in order to obtain a desired film thickness difference, the hardness and down force of the blade can be adjusted. Here, in more detail, the film thickness difference refers to the difference between the highest and lowest points of the composition layer when the substrate is cut in a direction perpendicular to the substrate surface and the cross section is observed. The difference in film thickness after scraping is preferably 2 μm or less, more preferably 1 μm or less. The composition layer before scraping in step (b) is in an uncured state, and at this time, the elastic modulus of the composition layer is preferably 0.5 to 4.5 GPa, more preferably 0.7 to 4.0 GPa. By being in this range, more uniform scraping can be achieved, the blade portion is less likely to be damaged, and scraping can be performed more stably. Before step (b), heating can be performed to facilitate processing of the composition layer. Even in such a case, it is preferable not to include a step of heating the substrate on which the composition layer is formed to 100°C or higher.

[0017] Fig. 1(a) shows a conceptual diagram of the state in which a composition layer is formed in a grooved region in step (a). A composition layer 2 is formed on a substrate 1 having grooves, and the film thickness difference 3 is large. Fig. 1(b) shows a conceptual diagram of the state of the composition layer after scraping in step (b). The film thickness difference is small.

[0018] Process (c) In step (c), the substrate is heated to cure the composition layer from which the excess portion has been removed. The heating temperature in this step is not particularly limited as long as it is a temperature that cures the composition layer. In order to promote the curing reaction and obtain a sufficient cured film, the curing temperature is preferably 200°C or higher, more preferably 300 to 1,000°C. The heating time is not particularly limited, and is preferably 1 minute to 10 hours, more preferably 1 to 180 minutes. The atmosphere during curing varies depending on the composition used, but is preferably a water vapor atmosphere or a nitrogen atmosphere. The curing step can be divided into two or more stages (more preferably three or more stages). For example, it can be first heated at a low temperature (for example, a temperature range of 200 to 400°C) in an atmosphere containing water vapor, then heated at a relatively low temperature (for example, a temperature range of 300 to 600°C) in an atmosphere containing water vapor, and then heated at a higher temperature (for example, 400 to 1,000°C) in an atmosphere not containing water vapor. It is also preferable to carry out pre-baking to remove the solvent between step (b) and the heating for curing in step (c). The composition layer cured in step (c) preferably has an elastic modulus of 8.0 to 80 GPa, more preferably 8.0 to 78 GPa.

[0019] Generally, when the composition layer is cured in a state where the thickness difference is large, the effect of thermal shrinkage during heating during curing becomes large, and cracks tend to occur easily. In the present invention, the thickness difference is reduced by scraping before the composition layer is cured. It is believed that this can suppress the occurrence of cracks during curing and obtain a hardened film with good film quality.

[0020] It is also preferable to further combine a chemical mechanical polishing step after step (c). Generally, it is considered that chemical mechanical polishing is inappropriate for materials with soft film quality. This is because the film is scratched or the abrasive grains are embedded in the film during polishing. After step (c), the film is in a hardened film state, so a chemical mechanical polishing step can be applied, and this application can further improve the flatness and achieve a desired film thickness. In addition, in the present invention, when planarizing by chemical mechanical polishing, the thickness of the composition layer is relatively thin due to the step (b), so that it is easy to planarize by chemical mechanical polishing.

[0021] A method for producing an electronic device according to the present invention comprises the method described above. The electronic device is preferably a semiconductor device.

[0022] [Cured film forming composition] The cured film-forming composition (hereinafter, sometimes referred to as the composition) used in the present invention is not particularly limited as long as it contains components capable of forming a cured film. The viscosity of the cured film-forming composition, when measured at 25° C. with a capillary viscometer, is preferably from 1.30 to 1.60 mPa·s, more preferably from 1.33 to 1.60 mPa·s, and even more preferably from 1.35 to 1.55 mPa·s.

[0023] The component capable of forming a cured film may be a polymer, a polymerizable monomer component, or a mixture thereof. The composition according to the present invention preferably contains a polymer, and examples of the polymer include an epoxy polymer, an acrylic polymer, a silicon-containing polymer, and the like, and more preferably a silicon-containing polymer. In a preferred embodiment, the composition used in the present invention is a siliceous film-forming composition.

[0024] In a preferred form of the invention, the composition employed in the present invention comprises a silicon-containing polymer selected from the group consisting of polysilazanes, polycarbosilazanes, polysiloxanes, and polysiloxazanes. The mass average molecular weight of the silicon-containing polymer is preferably 1,000 to 30,000, more preferably 1,200 to 28,000, and further preferably 1,500 to 25,000. In the present invention, the mass average molecular weight is a weight average molecular weight converted into polystyrene and can be measured by gel permeation chromatography using polystyrene as a standard. The same applies to other polymers. The content of the silicon-containing polymer is preferably from 10 to 100% by mass, and more preferably from 15 to 85% by mass, based on the total mass of the composition.

[0025] (Polysilazane) The structure of the polysilazane used in the present invention is not particularly limited, and may be selected from any suitable ones depending on the purpose. The polysilazane has a Si-N bond as the main skeleton, and may be either an inorganic compound or an organic compound, and may be linear, branched, or have a cyclic structure in part.

[0026] Preferably, the polysilazane contains 20 or more, preferably 20 to 350, repeating units selected from the group consisting of the following formulas (1-i) to (1-vi). In this case, it is preferable that each repeating unit is directly bonded to the other repeating units than (1-i) to (1-vi) without being connected via any other repeating units than (1-i) to (1-vi). [ka] (In the formula, R 1a ~R 1i are each independently hydrogen or C 1-4 (It is alkyl)

[0027] More preferably, the polysilazane used in the present invention is perhydropolysilazane (hereinafter referred to as PHPS). PHPS is a silicon-containing polymer that contains Si-N bonds as repeating units and is composed only of Si, N, and H. In this PHPS, all elements bonded to Si and N, except for the Si-N bonds, are H, and other elements such as carbon and oxygen are not substantially included. The simplest structure of perhydropolysilazane is a chain structure having the following repeating units. [ka]

[0028] The structure of PHPS is not limited, and it can have various structures other than those exemplified above, so long as it is a silicon-containing polymer that contains Si-N bonds as repeating units and is composed only of Si, N, and H. PHPS preferably has a cyclic structure or a crosslinked structure, particularly preferably a crosslinked structure.

[0029] The mass average molecular weight of the polysilazane is preferably from 1,200 to 28,000, and more preferably from 1,500 to 25,000, from the viewpoints of solubility in a solvent and reactivity.

[0030] (Polycarbosilazane) The structure of the polycarbosilazane used in the present invention is not particularly limited and can be selected from any structure depending on the purpose. The polycarbosilazane has a C-Si-N structure as the main skeleton, and preferably contains a repeating unit represented by the following formula (2-i) and a repeating unit represented by the following formula (2-ii). [ka] Where: R 2a , R 2b , and R 2c are each independently a single bond, hydrogen, or C 1-4 It is alkyl, preferably a single bond or hydrogen. R 2d , R2e and R 2f are each independently a single bond or hydrogen. However, R 2a , R 2b , R 2d and R 2e When is a single bond, it bonds to N in another repeating unit, and R 2c and R 2f When is a single bond, it bonds to Si contained in another repeating unit. n and m each independently represent 1 to 3, preferably 1 or 2, and more preferably 1. The polycarbosilazane is preferably polyperhydrocarbosilazane. The polyperhydrocarbosilazane is represented by the formula R 2a , R 2b , and R 2c is a single bond or hydrogen, and (CH2) in formula (2-i) n and (CH2) m Additionally, it does not have any hydrocarbon groups. The end groups of the polycarbosilazane are preferably -SiH3.

[0031] The polycarbosilazane according to the present invention preferably consists essentially of repeating units represented by formula (2-i) and repeating units represented by formula (2-ii). In the present invention, "substantially" means that 95% by mass or more of all the constituent units contained in the polycarbosilazane are repeating units represented by formula (2-i) and repeating units represented by formula (2-ii). More preferably, the polycarbosilazane does not contain any repeating units other than the repeating units represented by formula (2-i) and the repeating units represented by formula (2-ii).

[0032] The mass average molecular weight of the polycarbosilazane according to the present invention is preferably large in order to prevent the vaporization of low molecular weight components and suppress the volume change when filling a fine trench, while it is preferably low in viscosity in order to have good coating properties and to fill trenches with a high aspect ratio well. For these reasons, the mass average molecular weight of the polycarbosilazane is preferably 1,200 to 28,000, more preferably 1,500 to 25,000.

[0033] (Polysiloxane) The structure of the polysiloxane used in the present invention is not particularly limited, and can be selected from any structure depending on the purpose. The skeleton structure of polysiloxane can be classified into silicone skeleton (the number of oxygen atoms bonded to silicon atom is 2), silsesquioxane skeleton (the number of oxygen atoms bonded to silicon atom is 3), and silica skeleton (the number of oxygen atoms bonded to silicon atom is 4) according to the number of oxygen atoms bonded to silicon atom. In the present invention, any of these may be used. The polysiloxane molecule may contain a combination of multiple of these skeleton structures.

[0034] Preferably, the polysiloxane used in the present invention comprises a repeating unit represented by the following formula (3-i):

[0035] Equation (3-i) is as follows. [ka] Where: R 3a is hydrogen, monovalent to trivalent, C 1-30 or a linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group having a valence of 1 to 3. 6-30 is an aromatic hydrocarbon group, preferably hydrogen, C 1-6 Linear, branched or cyclic alkyl of C 6-10 and more preferably hydrogen, methyl, ethyl, or phenyl, and even more preferably methyl. The aliphatic hydrocarbon group and the aromatic hydrocarbon group are each unsubstituted or substituted with fluorine, hydroxy or C 1-8 is substituted with alkoxy; In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, no methylene is replaced, or one or more methylenes are replaced by oxy, imido or carbonyl, provided that R 3a is not hydroxy or alkoxy, R 3a If is divalent or trivalent, R 3a connects Si atoms contained in multiple repeating units together.

[0036] In formula (3-i), R 3a When R is a monovalent group, 3a Examples of R include, in addition to hydrogen, (i) alkyls such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl, (ii) aryls such as phenyl, tolyl, and benzyl, (iii) fluoroalkyls such as trifluoromethyl, 2,2,2-trifluoroethyl, and 3,3,3-trifluoropropyl, (iv) fluoroaryls, (v) cycloalkyls such as cyclohexyl, (vi) nitrogen-containing groups having an amino or imide structure such as isocyanate and amino, and (vii) oxygen-containing groups having an epoxy structure such as glycidyl, or an acryloyl structure or methacryloyl structure. Preferred are methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, tolyl, glycidyl, and isocyanate. As the fluoroalkyl, perfluoroalkyls, particularly trifluoromethyl and pentafluoroethyl, are preferred. R is a popular choice because it is easy to obtain raw materials, has high film hardness after curing, and has high chemical resistance. 3a It is preferable that R is methyl, since this increases the solubility of polysiloxane in a solvent and makes the cured film less likely to crack. 3a It is also preferred that is phenyl.

[0037] R 3a When R is a divalent or trivalent group, 3ais preferably, for example, (i) a group obtained by removing two or three hydrogen atoms from an alkane such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, and decane, (ii) a group obtained by removing two or three hydrogen atoms from a cycloalkane such as cycloheptane, cyclohexane, and cyclooctane, (iii) a group obtained by removing two or three hydrogen atoms from an aromatic compound composed only of hydrocarbons such as benzene and naphthalene, and (iv) a group obtained by removing two or three hydrogen atoms from a nitrogen- and / or oxygen-containing cyclic aliphatic hydrocarbon compound containing an amino group, an imino group, and / or a carbonyl group such as piperidine, pyrrolidine, and isocyanurate. (iv) is more preferable because it improves pattern droop and improves adhesion to the substrate.

[0038] The number of repeating units represented by formula (3-i) is preferably 1% or more, more preferably 20% or more, based on the total number of repeating units contained in the polysiloxane molecule. If the compounding ratio of the repeating units represented by formula (3-i) is high, the electrical properties of the cured film may decrease, the adhesion of the cured film to the contact film may decrease, and the hardness of the cured film may decrease, so that the film surface may be easily scratched. Therefore, the number of repeating units represented by formula (3-i) is preferably 95% or less, more preferably 90% or less, based on the total number of repeating units of the polysiloxane.

[0039] The polysiloxane used in the present invention preferably further contains a repeating unit represented by the following formula (3-ii) in addition to the repeating unit represented by formula (3-i). [ka] The number of repeating units represented by formula (3-ii) is preferably 8% or more, more preferably 10 to 99%, and even more preferably 10 to 80%, based on the total number of repeating units contained in the polysiloxane molecule. If the compounding ratio of the repeating units represented by formula (3-ii) is high, the compatibility with solvents and additives decreases, and the film stress increases, making cracks more likely to occur, while if the compounding ratio is low, the hardness of the cured film decreases.

[0040] The polysiloxane used in the present invention may contain repeating units other than those described above, but the number of repeating units other than those described above is preferably 20% or less, more preferably 10% or less, based on the total number of repeating units contained in the polysiloxane molecule. A preferred embodiment of the present invention is one in which no repeating units other than those described above are contained.

[0041] The polysiloxane used in the present invention preferably has a silanol at the end. Here, silanol refers to an OH group directly bonded to the Si skeleton of the polysiloxane, and is a polysiloxane containing the above-mentioned repeating units, etc., in which a hydroxyl group is directly bonded to a silicon atom. That is, -O in the above formula 0.5 -O 0.5 A silanol is formed by bonding with H.

[0042] The mass average molecular weight of the polysiloxane used in the present invention is preferably 1,000 to 30,000, more preferably 1,200 to 28,000, and even more preferably 1,500 to 25,000.

[0043] (Polysiloxazane) The structure of the polysiloxazane used in the present invention is not particularly limited and can be selected from any structure depending on the purpose. The polysiloxazane has a siloxane bond in the polysilazane main skeleton, and preferably contains a repeating unit represented by the following formula (4-i) and a repeating unit represented by the following formula (4-ii). [ka] (In the formula, R 4a , R 4b , R 4c , R 4d and R 4e are each independently a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group; R 4a and R 4b At least one of R is a hydrogen atom, 4d and R 4e At least one of the is a hydrogen atom. A siloxazane compound having a repeating unit represented by the formula: In the siloxazane compound, the ratio of O atoms to the total number of O atoms and N atoms is 5% or more and 25% or less; and The siloxazane compound was subjected to the inverse gate decoupling method. 29 In a spectrum obtained by Si-NMR, the ratio of the area of ​​the peak detected at -75 ppm to -90 ppm to the area of ​​the peak detected at -25 ppm to -55 ppm is 4.0% or less.

[0044] The mass average molecular weight of the polysiloxazane according to the present invention is preferably large in order to prevent the vaporization of low molecular weight components and suppress volume change when filling fine trenches, while it is preferably low in viscosity in order to achieve good coating properties and to fill trenches with high aspect ratios well. For these reasons, the mass average molecular weight of the polysiloxazane is preferably 1,200 to 28,000, more preferably 1,500 to 25,000.

[0045] (solvent) The composition used in the present invention may contain a solvent. The solvent is selected from those that uniformly dissolve or disperse each component contained in the composition. Specifically, examples of the solvent include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether, diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, and the like. Examples of the propylene glycol monoalkyl ethers include propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and other propylene glycol alkyl ether acetates, aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene, ethers such as dipropyl ether, dibutyl ether, and anisole, ketones such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone, alcohols such as isopropanol and propanediol, and alicyclic hydrocarbons such as cyclooctane and decalin. Xylene, dibutyl ether, and propylene glycol monomethyl ether are preferred. These solvents may be used alone or in combination of two or more. The content of the solvent is preferably 1 to 96% by mass, more preferably 20 to 85% by mass, based on the total mass of the composition.

[0046] The composition used in the present invention can be combined with further optional components as necessary. The optional components include, for example, surfactants. The content of the optional components, excluding the solvent, in the entire composition is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass.

[0047] The present invention will now be described with reference to examples, which are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0048] The synthesis and composition preparation steps in the following Examples and Comparative Examples are carried out in a low humidity state with a dew point temperature controlled to be −30.0° C. or lower.

[0049] In the following examples, the weight average molecular weight (Mw) is measured by gel permeation chromatography (GPC) using polystyrene as a standard. GPC is performed using an allianceTM e2695 type high-speed GPC system (Nihon Waters K.K.) and an organic solvent-based GPC column Shodex KF-805L (Showa Denko K.K.). The measurement is performed using monodisperse polystyrene as a standard sample, chloroform as a developing solvent, under measurement conditions of a flow rate of 0.6 milliliters / minute and a column temperature of 40°C, and then Mw is calculated as the molecular weight relative to the standard sample.

[0050] [Preparation of polysilazane-containing composition A] After replacing the inside of a 10L reaction vessel equipped with a cooling condenser, a mechanical stirrer and a temperature control device with dry nitrogen, 7,500 ml of dry pyridine is added to the reaction vessel and cooled to -3°C. Next, 500 g of dichlorosilane is added to produce a white solid adduct (SiH2Cl2·2C5H5N). After confirming that the reaction mixture has reached -3°C or lower, 350 g of ammonia is slowly blown into it while stirring. After continuing to stir for 30 minutes, dry nitrogen is blown into the liquid layer for 30 minutes to remove excess ammonia. The resulting slurry-like product is pressure-filtered using a 0.2 μm Teflon filter under a dry nitrogen atmosphere to obtain 6,000 ml of filtrate. Pyridine is distilled off using an evaporator, and xylene is added to obtain a 39.8 mass% xylene solution of a polysilazane intermediate. Add 4710g of dry pyridine, 150g of dry xylene, and 1650g of the 39.8% by mass polysilazane intermediate xylene solution obtained above, and stir until homogenous while bubbling with nitrogen gas at 0.5NL / min. Then, carry out a modification reaction at 110°C for 10.0 hours to obtain a 21.0% by mass polysilazane-containing composition A (hereinafter sometimes referred to as composition A). The obtained polysilazane has an Mw of 8,200.

[0051] [Preparation of polycarbosilazane-containing composition B] After replacing the inside of a 1L reaction vessel equipped with a cooling condenser, a mechanical stirrer and a temperature control device with dry nitrogen, 500 ml of dry pyridine is added to the reaction vessel and cooled to -3°C. Then, 9.67 g of dichlorosilane and 4.33 g of 1,1,3,3-tetrachloro-1,3-disilacyclobutane are added. After confirming that the reaction mixture has reached 0°C or lower, 10.3 g of ammonia is slowly blown into the reaction mixture while stirring. After continuing to stir for 30 minutes, dry nitrogen is blown into the liquid layer for 30 minutes to remove excess ammonia. The resulting slurry-like product is pressure-filtered using a 0.2 μm Teflon (registered trademark) filter under a dry nitrogen atmosphere to obtain 400 ml of filtrate. After distilling off the pyridine from the filtrate, xylene is added to obtain a 21.5 mass% polycarbosilazane-containing composition B (hereinafter sometimes referred to as composition B). The resulting polycarbosilazane has an Mw of 8,050.

[0052] [Preparation of polysiloxane-containing composition C] A 2L flask equipped with a stirrer, thermometer, and cooling tube is charged with 32.5g of 40% by mass tetra-n-butylammonium hydroxide (TBAH) aqueous solution and 308ml of 2-methoxypropanol (PGME). Next, a mixed solution of 19.6g of methyltrimethoxysilane and 9.2g of tetramethoxysilane is prepared in a dropping funnel. The mixed solution is dropped into the flask and stirred at 80°C for 2 hours. The temperature is lowered to room temperature, 500ml of normal propyl acetate (n-PA) is added, and then 1.1 equivalents of 3% by mass maleic acid aqueous solution relative to TBAH is added, and neutralized and stirred for 1 hour. 500ml of n-PA and 250ml of water are added to the neutralized solution, and the reaction solution is separated into two layers. The organic layer obtained is washed three times with 250cc of water and then concentrated under reduced pressure to remove water and solvent, and PGME is added to obtain a 19.8% by mass polysiloxane-containing composition C (hereinafter sometimes referred to as composition C). The resulting polysiloxane has Mw of 7,800.

[0053] [Preparation of polysiloxazane-containing composition D] After replacing the inside of a 10L reaction vessel equipped with a cooling condenser, a mechanical stirrer and a temperature control device with dry nitrogen, 2,800g of dry pyridine and 400g of a xylene solution of 39.8% by mass of polysilazane intermediate are introduced and cooled to -5°C while stirring. A mixture of 6g of pure water dissolved in 1,000g of dry pyridine and hydrous pyridine cooled to -5°C is added dropwise over 3 hours while stirring. After dropping, the solution is returned to room temperature and stirred for another hour. After distilling off pyridine, xylene is added to obtain a 20.2% by mass polysiloxazane-containing composition D (hereinafter sometimes referred to as composition D). The obtained polysiloxazane has Mw of 5,600.

[0054] [Examples 1 and 2] Compositions A and B are dropped onto a silicon wafer (8 inches) on which a pattern (groove with a width of 2 μm, a length of 20 μm, and a depth of 14 μm) is formed, and spin-coated at a rotation speed of 100 rpm to form a coating film. The formed coating film is thick in the area without grooves and is not flat. Scraping is then performed. A 10 cm wide separation member formed from a fragment of the silicon wafer is pressed vertically against the silicon wafer on which the coating film is formed with a force of 9.8 N, and scraped by moving it in the longitudinal direction of the groove at 5 cm / sec. By scraping, the excess part of the coating film on the area without grooves is removed, and the flatness of the coating film is improved. Next, the coating film is pre-baked on a hot plate under the conditions of 300°C / N2 / 10 minutes to dry it. Then, the dried film is replaced with a silica film by oxidizing it using a thermal diffusion furnace under the conditions of 300°C / 80% water vapor atmosphere / 1hr, and subsequently annealed under the conditions of 850°C / N2 / 60 minutes to obtain a hardened film. After that, the cross section of the patterned substrate, which has returned to room temperature, is observed using an electron microscope (Regulus 8230, Hitachi High-Tech Fielding) to measure the difference in film thickness between areas with grooves and areas without grooves, and to see whether or not cracks have occurred. Electron micrographs of Example 1 after curing in an area with grooves are shown in FIG. 2(c) and an area without grooves is shown in FIG. 2(d).

[0055] [Example 3] Using composition C, spin-coat a silicon wafer having the same pattern as above at a rotation speed of 100 rpm to form a coating film. After scraping in the same manner as above, pre-bake on a hot plate under the conditions of 120°C / air atmosphere / 180 seconds to dry the coating film. Then, anneal using a thermal diffusion furnace under the conditions of 650°C / N2 / 60 minutes to obtain a cured film. Similarly to the above, the difference in film thickness between the area with grooves and the area without grooves is measured, and it is observed whether or not cracks have occurred.

[0056] [Examples 4 to 8] Except for changing the force with which the separating member is pressed against the silicon wafer on which the composition has been applied as shown in Table 1, the difference in film thickness between the grooved and non-grooved areas is measured, and it is observed whether or not cracks have occurred, in the same manner as in Examples 1 and 2.

[0057] [Comparative Examples 1 and 2] Compositions A and B are dropped onto a silicon wafer having the same pattern as above, and spin-coated at a rotation speed of 100 rpm to form a coating film. The coating film is pre-baked on a hot plate under conditions of 300°C / N2 / 10 minutes to dry. The coating film is then oxidized to a silica film at 300°C / 80% water vapor atmosphere / 1 hour using a thermal diffusion furnace, and subsequently annealed at 850°C / N2 / 60 minutes to obtain a hardened film. As in Examples 1 and 2, the film thickness difference between the grooved and non-grooved areas is measured, and it is observed whether cracks have occurred. An electron microscope photograph of the grooved area of ​​Comparative Example 1 after curing is shown in FIG. 2(e).

[0058] [Comparative Example 3] Composition C is dropped onto a silicon wafer having the same pattern as above, and spin-coated at a rotation speed of 100 rpm to obtain a coating film. The coating film is pre-baked on a hot plate under the conditions of 120°C / air atmosphere / 180 seconds to dry. Then, annealing is performed using a thermal diffusion furnace at 650°C / N2 / 60 minutes to obtain a cured film. As in Examples 1 and 2, the film thickness difference between the grooved and non-grooved areas is measured, and it is observed whether cracks have occurred.

[0059] [Measurement of elastic modulus] The elastic modulus of the composition coating film before and after curing is measured using a nanoindenter ENT-2100 (Elionix). Before curing, it is the elastic modulus of the composition coating film before pre-baking, and after curing, it is the elastic modulus of the film after annealing. The modulus is measured in the non-grooved areas. In Comparative Examples 1 to 3, the elastic modulus after curing could not be measured due to the occurrence of cracks.

[0060] The results of Examples 1 to 8 and Comparative Examples 1 to 3 are summarized in Table 1. [Table 1] [Explanation of symbols]

[0061] 1. Substrate with grooves 2. Composition layer 3. Film thickness difference

Claims

1. A method for manufacturing a processed substrate comprising the following steps: (a) Applying a hardened film-forming composition in an amount sufficient to fill the grooves of a substrate to a substrate having grooves to form a composition layer; (b) Removing the excess portion of the composition layer by scraping it off using a separating member to form a substrate surface with improved flatness; and (c) Heat the substrate to harden the composition layer from which the excess portion has been removed.

2. The method according to claim 1, wherein the curing film-forming composition comprises a silicon-containing polymer selected from the group consisting of polysilazane, polycarbosilazane, polysiloxane, and polysiloxazan.

3. The method according to claim 2, wherein the mass-average molecular weight of the silicon-containing polymer is 1,000 to 30,000.

4. The method according to claim 2 or 3, wherein the content of the silicon-containing polymer is 10 to 100% by mass, based on the total amount of the cured film-forming composition.

5. The method according to any one of claims 1 to 3, wherein the cured film-forming composition comprises a solvent.

6. The method according to any one of claims 1 to 3, wherein the viscosity of the cured film-forming composition, as measured by a capillary viscometer at 25°C, is 1.30 to 1.60 mPa·s.

7. The method according to any one of claims 1 to 3, wherein the step of heating the substrate on which the composition layer is formed to 100°C or higher before step (b).

8. The method according to any one of claims 1 to 3, wherein the heating in step (c) is carried out at 300 to 1,000°C.

9. The method according to any one of claims 1 to 3, wherein the elastic modulus of the composition layer from which the excess is removed in step (b) is 0.5 to 4.5 GPa.

10. The method according to any one of claims 1 to 3, wherein the elastic modulus of the cured composition layer in step (c) is 8.0 to 80 GPa.

11. The method according to any one of claims 1 to 3, further comprising a chemical mechanical polishing step after step (c).

12. A method for manufacturing an electronic device, comprising the method according to any one of claims 1 to 3.

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