Adhesive film forming material, method for forming an adhesive film using the same, and pattern forming method using the adhesive film forming material

Abstract

The present invention relates to a bonding film forming material, a method for forming a bonding film using the bonding film forming material, and a method for forming a pattern using the bonding film forming material. The problem of the present invention is to provide a bonding film forming material that provides a bonding film having high adhesion to a resist upper film and having the effect of suppressing the collapse of fine patterns while forming a good pattern shape in a fine patterning process using a multilayer resist method in a semiconductor device manufacturing step, a pattern forming method using the material, and a method for forming the bonding film. The solution to the problem is a bonding film forming material, which is a bonding film forming material for a bonding film formed between a silicon-containing intermediate film and a resist upper film, characterized in that it contains: (A) a resin having a structural unit represented by the following general formula (1), (B) a cross-linking agent containing one or more compounds represented by the following general formula (2), (C) a photoacid generator, and (D) an organic solvent.

Description

Technical Field

[0001] The present invention relates to a hermetic film forming material, a method for forming a hermetic film using the hermetic film forming material, and a method for forming a pattern using the hermetic film forming material. Prior Art

[0002] With the high integration and high speed of LSIs, the miniaturization of pattern sizes has also progressed rapidly. Lithography technology, along with this miniaturization, has achieved the formation of fine patterns by shortening the wavelength of the light source and appropriately selecting a resist composition corresponding to the shortened wavelength of the light source. At the core of this is a positive photoresist composition used in a single layer. This single-layer positive photoresist composition has a framework in the resist resin that has etching resistance to dry etching with chlorine-based or fluorine-based gas plasmas, and has a resist mechanism such that the exposed portion dissolves. By dissolving the exposed portion in this way, a pattern is formed, and the remaining resist pattern is used as an etching mask to perform dry etching on the substrate to be processed coated with the photoresist composition.

[0003] However, when directly miniaturizing using the film thickness of the photoresist film used, that is, when further reducing the pattern width, the resolution performance of the photoresist film decreases. Moreover, if it is desired to develop the pattern of the photoresist film using a developer, the so-called aspect ratio becomes too large, and as a result, pattern collapse occurs. Therefore, with miniaturization, the film thickness of the photoresist film also becomes thinner.

[0004] On the other hand, for the processing of the substrate to be processed, a method is generally used in which a patterned photoresist film is used as an etching mask and the substrate to be processed is processed by dry etching. However, in reality, there is no dry etching method that can achieve complete etching selectivity between the photoresist film and the substrate to be processed. Therefore, in the processing of the substrate to be processed, the photoresist film is also damaged, resulting in the collapse of the photoresist film during the processing of the substrate to be processed and the resist pattern not being correctly transferred to the substrate to be processed. Thus, with the miniaturization of the pattern, higher dry etching resistance is required for the photoresist composition. Also, due to the shortening of the exposure wavelength, the resin used in the photoresist composition needs to be a resin with little light absorption at the exposure wavelength. Therefore, corresponding to the change to i-ray, KrF, and ArF, it has gradually changed to novolak resin, polyhydroxystyrene, and a resin having an aliphatic polycyclic framework. However, in reality, the etching rate in the aforementioned dry etching conditions is getting faster and faster, and the latest photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] Considering the above, it has become necessary to perform dry etching on the substrate to be processed using a thinner and weaker etching-resistant photoresist film, and ensuring the materials and processes in this processing step has become an urgent matter.

[0006] One of the methods for solving such problems is the multi-layer resist method. In this method, an intermediate film with different etching selectivity and photoresist film (i.e., the upper resist film) is inserted between the upper resist film and the substrate to be processed. After obtaining a pattern on the upper resist film, the pattern of the upper resist film is used as a dry etching mask, and the pattern is transferred to the intermediate film by dry etching. Then, the intermediate film is used as a dry etching mask, and the pattern is transferred to the substrate to be processed by dry etching.

[0007] One of the multi-layer resist methods is a three-layer resist method that can be implemented using general resist compositions used in the single-layer resist method. In this three-layer resist method, for example, an organic film derived from novolak resin or the like is formed on the substrate to be processed as the lower resist film, a silicon-containing film is formed thereon as the silicon-containing resist intermediate film, and a normal organic photoresist film is formed thereon as the upper resist film. For dry etching with fluorine-based gas plasmas, since the organic upper resist film has a good etching selectivity ratio with respect to the silicon-containing resist intermediate film, the pattern of the upper resist film is transferred to the silicon-containing resist intermediate film by dry etching using fluorine-based gas plasmas. In addition, for etching using oxygen or hydrogen, the silicon-containing resist intermediate film has a good etching selectivity ratio with respect to the lower resist film, so the pattern of the silicon-containing intermediate film is transferred to the lower resist film by etching using oxygen or hydrogen. According to this method, even if a photoresist composition that is difficult to form a pattern with a sufficient film thickness for directly processing the substrate to be processed or a photoresist composition that has insufficient dry etching resistance for processing the substrate is used, as long as the pattern can be transferred to a silicon-containing film (the silicon-containing resist intermediate film), a pattern of an organic film (the lower resist film) derived from novolak resin or the like that has sufficient dry etching resistance for processing can be obtained.

[0008] On the other hand, in recent years, ArF immersion lithography, EUV lithography, etc. have been developed, and the formation of finer patterns has gradually become possible. However, conversely, since ultra-fine patterns have a small contact area, they are extremely likely to collapse, and the suppression of pattern collapse is a very big problem. Recently, it is considered that the interaction between the surfaces of the upper resist film and the lower resist film in the fine pattern affects pattern collapse, and the performance of the lower resist film also needs to be improved.

[0009] In order to suppress pattern collapse, materials that use an underlayer film of a resist containing polar functional groups such as a lactone structure and a urea structure to improve the adhesion to the upper layer resist film have been reported (Patent Documents 1 and 2). However, in the current situation where finer pattern formation is required, the pattern collapse suppression performance of these materials is not sufficient. In addition, an underlayer film of a resist formed by combining a resin containing a phenolic hydroxyl group and a compound having a vinyl ether group has been reported, but its thermosetting property is not sufficient (Patent Document 3). Considering the above facts, materials with higher pattern collapse suppression performance and adhesion are required.

[0010] Prior Art Documents

[0011] Patent Documents

[0012] [Patent Document 1] International Publication No. 2003 / 017002

[0013] [Patent Document 2] International Publication No. 2018 / 143359

[0014] [Patent Document 3] Japanese Patent No. 5708938 Summary of the Invention

[0015] [Problems to be Solved by the Invention]

[0016] In view of the above facts, the present invention aims to provide a material for forming a conformal film, a pattern forming method using the material, and a method for forming the above conformal film, which have high adhesion to the upper layer resist film in a fine patterning process using a multi-layer resist method in semiconductor device manufacturing steps, and have an effect of suppressing collapse of fine patterns and can form a good pattern shape.

[0017] [Means for Solving the Problems]

[0018] In order to solve the above problems, the present invention provides a material for forming a conformal film, which is a material for forming a conformal film formed between a silicon-containing intermediate film and an upper layer resist film, and the material for forming a conformal film contains:

[0019] (A) A resin having a structural unit represented by the following general formula (1),

[0020] (B) A crosslinking agent containing one or more compounds represented by the following general formula (2),

[0021] (C) A photoacid generator, and

[0022] (D) An organic solvent.

[0023] [Chemical Formula 1]

[0024]

[0025] In the formula, R 01 is a hydrogen atom or a methyl group, R 02 is an alkyl group having 1 to 3 carbon atoms, m represents an integer of 1 or 2, n represents an integer of 0 to 4, and m + n is an integer of 1 or more and 5 or less. X represents a single bond or an alkylene group having 1 to 10 carbon atoms which may contain an oxygen atom.

[0026] [Chemical formula 2]

[0027]

[0028] In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. R 03 is a hydrogen atom or a methyl group. q is an integer of 1 to 5.

[0029] If it is such an adhesion film forming material, an adhesion film having high adhesion to the upper resist film, having an effect of suppressing collapse of fine patterns, and providing a good pattern shape can be formed.

[0030] Further, in the present invention, the silicon-containing intermediate film is preferably a silicon-containing resist intermediate film or an inorganic hard mask intermediate film.

[0031] In the present invention, such an intermediate film can be preferably used as the silicon-containing intermediate film.

[0032] Further, in the present invention, the aforementioned (C) photoacid generator preferably contains one or more compounds represented by the following general formula (3).

[0033] [Chemical formula 3]

[0034]

[0035] In the formula, R 04 , R 05 and R 06 each independently represent a linear alkyl or alkenyl group having 1 to 10 carbon atoms which may be substituted with a heteroatom or may have a heteroatom inserted therein, or a branched or cyclic alkyl or alkenyl group having 3 to 10 carbon atoms which may be substituted with a heteroatom or may have a heteroatom inserted therein, or an aryl or aralkyl group having 6 to 18 carbon atoms which may be substituted with a heteroatom or may have a heteroatom inserted therein. Further, any two of R 04 , R 05 and R 06 may be bonded to each other and form a ring together with the sulfur atom in the formula. Y− represents any one of the following general formulas (4) or (5).

[0036] [Chemical formula 4]

[0037] R 07 -CF 2 -SO 3 - (4)

[0038]

[0039] In the formula, R 07 and R 08 each independently represents a monovalent hydrocarbon group having an aliphatic ring structure with 3 to 40 carbon atoms which may be substituted with a heteroatom or into which a heteroatom may be inserted.

[0040] If it is such a conformal film-forming material, it can have the effect of suppressing the collapse of fine patterns, and can moderately adjust the pattern shape, exposure sensitivity, etc. of the upper layer film of the resist.

[0041] At this time, the aforementioned general formula (4) is preferably represented by the following general formula (4').

[0042] [Chemical formula 5]

[0043]

[0044] In the formula, R 09 represents a hydrogen atom or a trifluoromethyl group. R 10 represents a monovalent hydrocarbon group having an aliphatic ring structure with 3 to 30 carbon atoms which may be substituted with a heteroatom or into which a heteroatom may be inserted.

[0045] If it is such a conformal film-forming material, it has sufficient acidity, and can moderately adjust acid diffusion, and sometimes it is effective in reducing residues from the upper layer film of the resist.

[0046] Also, in the present invention, X in the aforementioned general formula (1) is preferably -C(=O)O-.

[0047] If it is such a conformal film-forming material, it can form a conformal film having higher adhesion to the upper layer film of the resist and having the effect of suppressing the collapse of fine patterns.

[0048] Also, in the present invention, the weight average molecular weight of the aforementioned (A) resin is preferably 1,000 to 20,000.

[0049] If it is a conformal film-forming material containing a resin having such a weight average molecular weight range, it has excellent film-forming properties, and can suppress the generation of sublimates during heat hardening and suppress the contamination of the apparatus caused by the sublimates. Also, it can suppress the occurrence of coating defects and become a more excellent conformal film-forming material.

[0050] Also, in the present invention, the content of the aforementioned (B) crosslinking agent relative to the content of the aforementioned (A) resin is preferably 10% by mass to 50% by mass.

[0051] If it is such a conformal film-forming material, since the crosslinking reactivity increases, the solvent resistance of the conformal film can be improved, and at the same time, a conformal film maintaining high adhesion to the upper layer film of the resist can be formed.

[0052] Further, in the present invention, the content of the foregoing (C) photoacid generator relative to the content of the foregoing (A) resin is preferably 1% by mass to 20% by mass.

[0053] If such a conformal film-forming material is used, the pattern shape, exposure sensitivity, etc. of the upper resist film can be appropriately adjusted, which is suitable for optical lithography of the upper resist film.

[0054] Further, in the present invention, it is preferably further contained one or more of a surfactant, a plasticizer, and a pigment.

[0055] By adding or selecting the above various additives, the properties corresponding to customer requirements such as film-forming property, filling property, and optical properties can be finely adjusted, which is more ideal in practical use.

[0056] Further, in the present invention, it is preferably free of a thermal acid generator.

[0057] If such a conformal film-forming material is used, it is possible to prevent the surface of the conformal film from being acidic after baking, and the acid generated diffuses into the upper resist film, resulting in a situation where the pattern shape becomes an undercut shape, inducing pattern collapse, or conversely becoming a trailing shape.

[0058] Further, the present invention provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0059] (I-1) Forming a lower resist film on the substrate to be processed,

[0060] (I-2) Forming a silicon-containing resist intermediate film on the lower resist film,

[0061] (I-3) Coating the above-described conformal film-forming material on the silicon-containing resist intermediate film and then performing heat treatment to thereby form a conformal film,

[0062] (I-4) Using a photoresist material to form an upper resist film on the conformal film,

[0063] (I-5) After pattern exposure of the upper resist film, developing with a developer and forming a pattern on the foregoing upper resist film,

[0064] (I-6) Using the patterned upper resist film as a mask and transferring the pattern to the foregoing conformal film by dry etching,

[0065] (I-7) Using the patterned conformal film as a mask and transferring the pattern to the foregoing silicon-containing resist intermediate film by dry etching, and

[0066] (I-8) Using the silicon-containing resist intermediate film with the transferred pattern as a mask, the pattern is transferred to the aforementioned resist lower layer film by dry etching.

[0067] Furthermore, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0068] (II-1) Forming a resist lower layer film on the substrate to be processed,

[0069] (II-2) Forming an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist lower layer film,

[0070] (II-3) Coating the above-described adhesion film forming material on the inorganic hard mask intermediate film and then performing heat treatment to thereby form an adhesion film,

[0071] (II-4) Using a photoresist material to form a resist upper layer film on the adhesion film,

[0072] (II-5) After performing pattern exposure on the resist upper layer film, developing with a developer, and forming a pattern on the aforementioned resist upper layer film,

[0073] (II-6) Using the resist upper layer film with the formed pattern as a mask, and transferring the pattern to the aforementioned adhesion film by dry etching,

[0074] (II-7) Using the adhesion film with the formed pattern as a mask, and transferring the pattern to the aforementioned inorganic hard mask intermediate film by dry etching, and

[0075] (II-8) Using the inorganic hard mask intermediate film with the transferred pattern as a mask, and transferring the pattern to the aforementioned resist lower layer film by dry etching.

[0076] Thus, the adhesion film forming material of the present invention can be ideally used in various pattern formation methods such as a four-layer resist process for forming the aforementioned adhesion film on a silicon-containing intermediate film (silicon-containing resist intermediate film, inorganic hard mask intermediate film). For these pattern formation methods, pattern collapse can be effectively alleviated by adhesion film formation, and it is suitable for optical lithography of the resist upper layer film.

[0077] At this time, it is preferable to form the aforementioned inorganic hard mask intermediate film by CVD method or ALD method.

[0078] Furthermore, in the present invention, it is preferable to use optical lithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprinting, or a combination thereof as the method for forming a circuit pattern on the aforementioned resist upper layer film.

[0079] Further, in the present invention, development using alkali development or organic solvent development is preferably used as the development method.

[0080] In the present invention, by using the pattern formation method as described above, pattern formation can be carried out favorably and efficiently.

[0081] Further, in the present invention, a semiconductor device substrate or a substrate obtained by forming any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxycarbide film, and a metal oxynitride film on the semiconductor device substrate is preferably used as the substrate to be processed.

[0082] At this time, silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or their alloys are preferably used as the metal.

[0083] In the case of the pattern formation method of the present invention, the substrate to be processed as described above can be processed as described above to form a pattern.

[0084] Further, the present invention provides a method for forming a sealing film, which is a method for forming a sealing film that functions as a sealing layer used in the manufacturing process of a semiconductor device. The sealing film forming material is spin-coated on the substrate to be processed, and the substrate coated with the sealing film forming material is heat-treated at a temperature of 100°C or higher and 300°C or lower for a range of 10 to 600 seconds to form a hardened film.

[0085] Further, the present invention provides a method for forming a sealing film, which is a method for forming a sealing film that functions as a sealing layer used in the manufacturing process of a semiconductor device. The sealing film forming material is spin-coated on the substrate to be processed, and the substrate coated with the sealing film forming material is heat-treated in a gas environment with an oxygen concentration of 0.1% or higher and 21% or lower to form a hardened film.

[0086] By using such a method, the crosslinking reaction during the formation of the sealing film can be promoted, and the mixing with the upper layer film of the resist can be suppressed to a greater extent. Further, by appropriately adjusting the heat treatment temperature, time, and oxygen concentration within the aforementioned ranges, the effect of suppressing the pattern collapse of the sealing film suitable for the application can be achieved, and the pattern shape adjustment characteristics of the upper layer film of the resist can be obtained.

[0087] Further, the present invention provides a method for forming a sealing film, which is a method for forming a sealing film that functions as a sealing layer used in the manufacturing process of a semiconductor device. The sealing film forming material is spin-coated on the substrate to be processed, and the substrate coated with the sealing film forming material is heat-treated in a gas environment with an oxygen concentration of less than 0.1% to form a hardened film.

[0088] By using such a method, even when the substrate to be processed contains a material that is unstable upon heating in an oxygen environment, deterioration of the substrate to be processed is not caused, crosslinking reactions during formation of the adhesion film can be promoted, and mixing with the upper layer film can be suppressed to a greater extent, which is useful.

[0089] [Effects of the Invention]

[0090] As described above, in the case of the present invention, an adhesion film forming material having high adhesion to the upper resist film and having an effect of suppressing collapse of fine patterns can be provided. Further, the adhesion film forming material has high adhesion and has an effect of suppressing collapse of fine patterns, and at the same time, can moderately adjust the pattern shape, exposure sensitivity, etc. of the upper resist film. Therefore, it is extremely useful in a multi-layer resist process such as a four-layer resist process in which the adhesion film is formed on a silicon-containing intermediate film. Further, in the case of the method for forming an adhesion film of the present invention, an adhesion film that is sufficiently hardened on the substrate to be processed and has high adhesion to the upper resist film can be formed. Further, in the case of the pattern forming method of the present invention, fine patterns can be formed with high precision on the substrate to be processed in a multi-layer resist process. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 (A) to (G) are explanatory views of an example of a pattern forming method in a four-layer resist process of the present invention.

[0092] Figure 2 is an explanatory view showing a method for measuring adhesion in an example. DETAILED DESCRIPTION OF THE INVENTION

[0093] As described above, in a fine patterning process using a multi-layer resist method in a semiconductor device manufacturing process, an adhesion film forming material having high adhesion to the upper resist film and having an effect of suppressing collapse of fine patterns, a pattern forming method using the material, and a method for forming an adhesion film are required.

[0094] As a result of repeated and in-depth studies by the present inventors on the above problems, they continuously searched for an adhesion film forming material having high adhesion to the upper resist film due to formation of an adhesion film and having an effect of suppressing collapse of fine patterns, and a pattern forming method using the material in multi-layer lithography. As a result, it was found that an adhesion film forming material containing a compound having a specific structure as a main component, a pattern forming method using the material, and a method for forming an adhesion film are very effective, and thus the present invention was completed.

[0095] That is, the present invention relates to an adhesion film forming material which is an adhesion film forming material for an adhesion film formed between a silicon-containing intermediate film and an upper resist film, and the adhesion film forming material contains:

[0096] ​​(A) A resin having a structural unit represented by the following general formula (1),

[0097] (B) A crosslinking agent containing one or more compounds represented by the following general formula (2),

[0098] (C) A photoacid generator, and

[0099] (D) An organic solvent.

[0100] [Chemical formula 6]

[0101]

[0102] In the formula, R 01 is a hydrogen atom or a methyl group, R 02 is an alkyl group having 1 to 3 carbon atoms, m represents an integer of 1 or 2, n represents an integer of 0 to 4, and m + n is an integer of 1 or more and 5 or less. X represents a single bond or an alkylene group having 1 to 10 carbon atoms which may contain an oxygen atom.

[0103] [Chemical formula 7]

[0104]

[0105] In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. R 03 is a hydrogen atom or a methyl group. q is an integer of 1 to 5.

[0106] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0107] [Adhesive film forming material]

[0108] The present invention provides an adhesive film forming material for forming an adhesive film between a silicon-containing intermediate film and an upper resist film. The adhesive film forming material contains:

[0109] (A) A resin having a structural unit represented by the following general formula (1),

[0110] (B) A crosslinking agent containing one or more compounds represented by the following general formula (2),

[0111] (C) A photoacid generator, and

[0112] (D) An organic solvent.

[0113] In addition, in the adhesive film forming material of the present invention, the (A) resin may be used alone or in combination of two or more. In addition, the adhesive film forming material may also contain components other than the above components (A) to (D). Each component will be described below.

[0114] [(A) Resin]

[0115] The (A) resin contained in the hermetic film forming material of the present invention is represented by the following general formula (1).

[0116] [Chemical formula 8]

[0117]

[0118] In the formula, R 01 is a hydrogen atom or a methyl group, R 02 is an alkyl group having 1 to 3 carbon atoms, m represents an integer of 1 or 2, n represents an integer of 0 to 4, and m + n is an integer of 1 or more and 5 or less. X represents a single bond or an alkylene group having 1 to 10 carbon atoms which may contain an oxygen atom.

[0119] R in the aforementioned general formula (1) 01 is a hydrogen atom or a methyl group, R 02 is an alkyl group having 1 to 3 carbon atoms, m represents an integer of 1 or 2, n represents an integer of 0 to 4, and m + n is an integer of 1 or more and 5 or less. Preferably, m is an integer of 1 or 2, n is an integer of 0 or 1, and m + n is an integer of 1 or more and 3 or less. More preferably, m is 1, n is 0, and m + n is 1.

[0120] X in the aforementioned general formula (1) is a single bond or an alkylene group having 1 to 10 carbon atoms which may contain an oxygen atom. The oxygen atom in the aforementioned X may form a carbonyl group, a hydroxyl group, or an ether bond. For example, the ether bond is an alkylene group having 1 carbon atom and containing an oxygen atom.

[0121] Regarding the aforementioned X, the following may be specifically exemplified, but are not limited thereto.

[0122] [Chemical formula 9]

[0123]

[0124] In the formula, the broken line represents an atomic bond.

[0125] R in the aforementioned general formula (1) 02 may include a methyl group, an ethyl group, a propyl group, and an isopropyl group. From the viewpoint of considering the adhesion to the upper layer film of the resist, a methyl group is preferred.

[0126] Examples of the resin represented by the aforementioned general formula (1) may be specifically exemplified as follows, but are not limited thereto. In the following formula, R 01 is the same as the aforementioned one.

[0127] [Chemical formula 10]

[0128]

[0129] [Chemical formula 11]

[0130]

[0131] In the case of an adhesion film forming material containing these resins, an adhesion film forming material having high adhesion to the upper resist film and having an effect of suppressing collapse of fine patterns can be formed, and it can be easily manufactured.

[0132] By using an adhesion film forming material containing such a resin in forming a multilayer resist film used in fine processing in a manufacturing process of a semiconductor device or the like, an adhesion film forming material for forming an adhesion film having high adhesion to the upper resist film and having an effect of suppressing collapse of fine patterns, a method for forming an adhesion film, and a method for forming a pattern can be provided.

[0133] The above-mentioned resin can be synthesized by a known method by polymerizing each monomer which has been protected with a protecting group as required, and then performing a deprotection reaction as required. The polymerization reaction is not particularly limited, and radical polymerization or anionic polymerization is preferably used. These methods can be referred to Japanese Patent Laid-Open No. 2004-115630.

[0134] The weight average molecular weight (Mw) of the above-mentioned resin is preferably 1,000 to 20,000, more preferably 5,000 to 15,000. If Mw is 1,000 or more, it has excellent film-forming properties, and generation of sublimates during heat hardening can be suppressed and contamination of the device caused by sublimates can be suppressed. On the other hand, if Mw is 20,000 or less, poor coatability and occurrence of coating defects caused by insufficient solubility in a solvent can be suppressed. Further, the molecular weight distribution (Mw / Mn) of the above-mentioned resin is preferably 1.0 to 2.8, more preferably 1.0 to 2.5. In addition, in the present invention, Mw and the molecular weight distribution are polystyrene conversion measurement values obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0135] [(B) Crosslinking agent]

[0136] The adhesion film forming material of the present invention contains a crosslinking agent represented by the following general formula (2) as the component (B). Thereby, the curability is improved and mutual mixing with the upper resist film is suppressed. In addition to having this effect, the film thickness uniformity may sometimes be improved. Further, in the case of the crosslinking agent represented by the following general formula (2), the crosslinking speed is fast compared with other crosslinking agents, and sufficient curability can be obtained even when a thermal acid generator is not contained. Therefore, in the adhesion film forming material of the present invention, a thermal acid generator is not necessary, and it is preferable not to contain a thermal acid generator.

[0137] [Chemical formula 12]

[0138]

[0139] In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. R 03 is a hydrogen atom or a methyl group. q is an integer of 1 to 5.

[0140] Q in the aforementioned general formula (2) is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. q is an integer of 1 to 5, more preferably 2 or 3. When Q is a q-valent hydrocarbon group having 1 to 20 carbon atoms, Q is a q-valent hydrocarbon group formed by removing q hydrogen atoms from a hydrocarbon having 1 to 20 carbon atoms. Examples of the hydrocarbon having 1 to 20 carbon atoms at this time include: methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane.

[0141] R in the aforementioned general formula (2) 03 is a hydrogen atom or a methyl group, preferably a methyl group.

[0142] Examples of the compound represented by the aforementioned general formula (2) include, but are not limited to, the following compounds. In the following formula, R 03 is the same as described above.

[0143] [Chemical formula 13]

[0144]

[0145] [Chemical formula 14]

[0146]

[0147] The aforementioned (B) crosslinking agent can be used alone or in combination of two or more. The addition amount of the (B) crosslinking agent is preferably 10% by mass to 50% by mass, more preferably 15% by mass to 30% by mass, based on the content (100% by mass) of the aforementioned (A) resin. If the addition amount is 10% by mass or more, sufficient curability is achieved, and mutual mixing with the upper layer film of the resist can be suppressed. On the other hand, if the addition amount is 50% by mass or less, there is a concern that the ratio of the (A) resin in the composition becomes low and the adhesion deteriorates.

[0148] [(C) Photoacid generator]

[0149] Furthermore, the adhesion film forming material of the present invention contains a photoacid generator as the (C) component. The photoacid generator is preferably represented by the following general formula (3).

[0150] [Chemical formula 15]

[0151]

[0152] In the formula, R 04 , R 05 and R 06Each independently represents a linear alkyl or alkenyl having 1 to 10 carbon atoms or a branched or cyclic alkyl or alkenyl having 3 to 10 carbon atoms, which may be substituted with a heteroatom or have a heteroatom inserted therein, or represents an aryl or aralkyl having 6 to 18 carbon atoms, which may be substituted with a heteroatom or have a heteroatom inserted therein. Further, R 04 、R 05 and R 06 Any two of them may also be bonded to each other and together with the sulfur atom in the formula form a ring. Y− represents any one of the following general formula (4) or (5).

[0153] [Chemical Formula 16]

[0154] R 07 -CF 2 -SO 3 - (4)

[0155]

[0156] In the formula, R 07 and R 08 Each independently represents a monovalent hydrocarbon group containing an aliphatic ring structure having 3 to 40 carbon atoms, which may be substituted with a heteroatom or have a heteroatom inserted therein.

[0157] At this time, the aforementioned general formula (4) is preferably represented by the following general formula (4’).

[0158] [Chemical Formula 17]

[0159]

[0160] In the formula, R 09 represents a hydrogen atom or a trifluoromethyl group. R 10 represents a monovalent hydrocarbon group containing an aliphatic ring structure having 3 to 30 carbon atoms, which may be substituted with a heteroatom or have a heteroatom inserted therein.

[0161] R 04 、R 05 and R 06Each independently represents a linear or branched or cyclic alkyl or alkenyl group having 1 to 10 carbon atoms, which may be substituted or inserted with a hetero atom, or an aryl or aralkyl group having 6 to 18 carbon atoms, which may be substituted or inserted with a hetero atom. Specifically, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, hexenyl, and cyclohexenyl; aryl groups such as phenyl, naphthyl, and thienyl; aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl, etc., preferably an aryl group. Furthermore, part of the hydrogen atoms of these groups may be replaced with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, or heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms may be inserted, and as a result, hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydrides, and haloalkyl groups may be formed or inserted. Furthermore, R 04 、R 05 and R 06 Any two of can also be bonded to each other and form a ring together with the sulfur atom in the formula.

[0162] In addition, regarding Y in the above general formula (3) - , is any one of the above general formula (4) or (5), and specific examples include the following, but are not limited to these. In the general formula (4) or (5), R 07 and R 08 Independently represent a monovalent hydrocarbon group containing an aliphatic ring structure having 3 to 40 carbon atoms which may be substituted with a heteroatom or may have a heteroatom inserted therein, preferably 1-norbornyl, 1-adamantyl, 2-adamantyl, 4-oxo-1-adamantyl.

[0163] [Chemistry 18]

[0164]

[0165] [Chemistry 19]

[0166]

[0167] [Chemistry 20]

[0168]

[0169] [Chemistry 21]

[0170]

[0171] [Chemistry 22]

[0172]

[0173] [Chemistry 23]​

[0174]

[0175] [Chemical Formula 24]

[0176]

[0177] [Chemical Formula 25]

[0178]

[0179] In the general formula (4’), R 09 represents a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 10 represents a monovalent hydrocarbon group having an aliphatic ring structure with 3 to 30 carbon atoms that may be substituted by a heteroatom or in which a heteroatom may be inserted, preferably a 1-norbornanyl group, a 1-adamantyl group, a 2-adamantyl group, or a 4-oxo-1-adamantyl group.

[0180] By using one kind of the foregoing (C) photoacid generator alone or in combination of two or more kinds, the pattern shape, exposure sensitivity, etc. of the upper layer film of the resist can be moderately adjusted. The addition amount of the (C) photoacid generator is preferably 1% by mass to 20% by mass, more preferably 5% by mass to 15% by mass, relative to the content (100% by mass) of the foregoing (A) resin. If the addition amount of the (C) photoacid generator is within the foregoing range, the resolution is good, and there is no concern about the problem of foreign matter generation during resist development or peeling.

[0181] [(D) organic solvent]

[0182] Regarding the (D) organic solvent contained in the adhesion film forming material used in the method for forming the adhesion film of the present invention, if it dissolves the foregoing (A) resin, (B) crosslinking agent, and (C) photoacid generator, and dissolves other additives, etc. when other additives, etc. are present, there is no particular limitation. Specifically, solvents having a boiling point of less than 180°C such as those described in paragraphs (0091) to (0092) of Japanese Patent Application Laid-Open No. 2007-199653 can be used. Among them, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and mixtures of two or more of them can be preferably used.

[0183] If it is such a composition, it can be coated by spin coating, and further, since it contains the adhesion film forming material of the present invention as described above, it becomes an adhesion film forming composition for forming an adhesion film having high adhesion to the upper layer film of the resist and having an effect of suppressing collapse of fine patterns.

[0184] [Other additives]

[0185] In the hermetic film forming material of the present invention, in addition to containing the above components (A) to (D), one or more of a surfactant, a plasticizer, and a pigment may be further contained. Each component will be described below.

[0186] (Surfactant)

[0187] In the hermetic film forming material of the present invention, a surfactant may be added in order to improve coatability in spin coating. As the surfactant, for example, those described in (0142) to (0147) of Japanese Unexamined Patent Application Publication No. 2009-269953 can be used.

[0188] (Plasticizer)

[0189] Furthermore, in the hermetic film forming material of the present invention, a plasticizer may be added. The plasticizer is not particularly limited, and various known plasticizers of various systems can be widely used. Examples thereof include low molecular weight compounds such as phthalates, adipates, phosphates, trimellitates, and citrates; polymers such as polyether-based, polyester-based, and polyacetal-based polymers described in Japanese Unexamined Patent Application Publication No. 2013-253227.

[0190] (Pigment)

[0191] Furthermore, in the hermetic film forming material of the present invention, a pigment may be added in order to further improve the resolution during patterning of multilayer lithography. The pigment is not particularly limited as long as it is a compound having appropriate absorption in the exposure wavelength, and various known compounds can be widely used. Examples thereof include benzenes, naphthalenes, anthracenes, phenanthrenes, pyrenes, isocyanuric acids, and triazines.

[0192] Furthermore, the hermetic film forming material of the present invention is extremely useful as a hermetic film material for a multilayer resist process such as a four-layer resist process using a resist underlayer film and a silicon-containing intermediate film.

[0193] The aforementioned silicon-containing intermediate film can be set as a silicon-containing resist intermediate film or an inorganic hard mask intermediate film according to the pattern forming method described later. The aforementioned inorganic hard mask intermediate film is preferably selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film.

[0194] [Method for forming a hermetic film]

[0195] The present invention provides a method for forming a hermetic film that uses the aforementioned hermetic film forming material and has high adhesion to an upper resist film and an effect of suppressing collapse of fine patterns in a fine patterning process using a multilayer resist method in a semiconductor device manufacturing step.

[0196] The method for forming the hermetic film of the present invention is to coat the above-mentioned hermetic film forming material on the substrate to be processed by spin coating or the like. After spin coating, in order to evaporate the organic solvent and prevent mutual mixing with the upper resist film, the silicon-containing intermediate film, etc., baking (heat treatment) for promoting crosslinking reaction is carried out. The baking is preferably carried out in the range of 100 °C or higher and 300 °C or lower for 10 to 600 seconds, and more preferably in the range of 200 °C or higher and 250 °C or lower for 10 to 300 seconds. Considering the damage to the hermetic film and the influence on the deformation of the wafer, the upper limit of the heating temperature for lithography in wafer processing should be set at 300 °C or lower, and more preferably 250 °C or lower.

[0197] Furthermore, the method for forming the hermetic film of the present invention can also form the hermetic film by coating the hermetic film forming material of the present invention on the substrate to be processed by the same spin coating method or the like as described above, and calcining the hermetic film forming material in a gas environment with an oxygen concentration of 0.1% or more and 21% or less to harden it. By calcining the hermetic film forming material of the present invention in such an oxygen environment, a sufficiently hardened film can be obtained.

[0198] The gas environment during baking can be not only in air, but also sealed with inert gases such as N 2 , Ar, He, etc. At this time, a gas environment with an oxygen concentration less than 0.1% can be set. Also, the baking temperature, etc. can be set in the same manner as described above. Even when the substrate to be processed contains materials that are unstable to heating in an oxygen environment, deterioration of the substrate to be processed will not occur, and the crosslinking reaction during hermetic film formation can be promoted.

[0199] [Pattern formation method]

[0200] In the present invention, for a patterning method using a four-layer resist process with the aforementioned hermetic film forming material, the following two methods are provided. First, a patterning method is provided, which is a method of forming a pattern on a substrate to be processed. At least an organic film material is used to form an underlying resist film on the substrate to be processed, and then a silicon-containing intermediate film (silicon-containing resist intermediate film) is formed on the underlying resist film using a resist intermediate film material containing silicon atoms. Then, a hermetic film is formed on the silicon-containing resist intermediate film using the hermetic film forming material of the present invention. Then, a resist upper film is formed on the hermetic film using a resist upper film material composed of a photoresist composition to form a multilayer resist film. After exposing the pattern circuit region of the aforementioned resist upper film, development is performed using a developer to form a resist upper film pattern on the aforementioned resist upper film. Then, the obtained resist upper film pattern is used as an etching mask to etch the aforementioned hermetic film to form a hermetic film pattern. Then, the obtained hermetic film pattern is used as an etching mask to etch the aforementioned silicon-containing resist intermediate film to form a silicon-containing resist intermediate film pattern. Then, the obtained silicon-containing resist intermediate film pattern is used as an etching mask to etch the aforementioned underlying resist film to form an underlying resist film pattern. Then, the obtained underlying resist film pattern is used as an etching mask to etch the aforementioned substrate to be processed to form a pattern on the aforementioned substrate to be processed.

[0201] The silicon-containing resist intermediate film of the aforementioned four-layer resist process can also desirably use an intermediate film based on polysilsesquioxane. By making the silicon-containing resist intermediate film have an antireflection effect, reflection can be suppressed. Especially for 193 nm exposure, if a material containing a large amount of aromatic groups and having high substrate etching resistance is used as the underlying resist film, the k value will become high and the substrate reflection will become high. However, by suppressing reflection using the silicon-containing resist intermediate film, the substrate reflection can be made 0.5% or less. For a silicon-containing resist intermediate film having an antireflection effect, anthracene can be desirably used for 248 nm and 157 nm exposure, and a polysilsesquioxane pendant with a light-absorbing group having a phenyl group or a silicon-silicon bond and crosslinked by an acid or heat can be desirably used for 193 nm exposure.

[0202] At this time, compared with the CVD method, the method of forming the silicon-containing resist intermediate film by spin coating has the advantages of simplicity and economy.

[0203] Further, an inorganic hard mask intermediate film can also be formed as a silicon-containing intermediate film. In this case, an organic film material can be used to form an underlayer film of the resist on at least the substrate to be processed, and then an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the underlayer film of the resist. Then, a conformal film is formed on the inorganic hard mask intermediate film using the conformal film forming material of the present invention. Then, an upper layer film material of the resist composed of a photoresist composition is used to form an upper layer film of the resist on the conformal film. After exposing the pattern circuit region of the upper layer film of the resist, development is carried out using a developer to form an upper layer film pattern of the upper layer film of the resist on the upper layer film of the resist. Then, the obtained upper layer film pattern of the upper layer film of the resist is used as an etching mask to etch the conformal film to form a conformal film pattern. Then, the obtained conformal film pattern is used as an etching mask to etch the inorganic hard mask intermediate film to form an inorganic hard mask intermediate film pattern. Then, the obtained inorganic hard mask intermediate film pattern is used as an etching mask to etch the underlayer film of the resist to form an underlayer film pattern of the underlayer film of the resist. Then, the obtained underlayer film pattern of the underlayer film of the resist is used as an etching mask to etch the substrate to be processed to form a pattern on the substrate to be processed.

[0204] As described above, when forming an inorganic hard mask intermediate film on the underlayer film of the resist, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film (SiON film) can be formed by a CVD method, an ALD method, or the like. For example, regarding the formation method of the silicon nitride film, it is described in Japanese Patent Application Laid-Open No. 2002-334869 and International Publication No. 2004 / 066377. The film thickness of the inorganic hard mask intermediate film is preferably 5 to 200 nm, more preferably 10 to 100 nm. Further, the SiON film having a high antireflection film effect can be preferably used as the inorganic hard mask intermediate film. Since the substrate temperature when forming the SiON film reaches 300 to 500 °C, the underlayer film of the resist must withstand a temperature of 300 to 500 °C.

[0205] The upper layer film of the resist in the above four-layer resist process can be either positive or negative, and the same photoresist composition as that usually used can be used. After spin-coating the photoresist composition, prebaking is carried out, preferably in the range of 60 to 180 °C for 10 to 300 seconds. Then, exposure is carried out according to the usual method, and then post-exposure baking (PEB) and development are carried out to obtain an upper layer film pattern of the upper layer film of the resist. In addition, the thickness of the upper layer film of the resist is not particularly limited, preferably 30 to 500 nm, particularly preferably 50 to 400 nm.

[0206] A circuit pattern (upper layer film pattern of the resist) is formed on the upper layer film of the resist. When forming the circuit pattern, it is preferably formed by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprinting, or a combination thereof.

[0207] In addition, the exposure light may include high-energy rays with a wavelength of 300 nm or less. Specifically, it may include far ultraviolet rays, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F 2 laser (157 nm), Kr 2 laser (146 nm), Ar 2 laser (126 nm), soft X-rays (EUV) of 3 to 20 nm, electron beam (EB), ion beam, X-rays, etc.

[0208] Also, for the formation of the circuit pattern, it is advisable to use alkali development or an organic solvent to develop the circuit pattern.

[0209] Then, the obtained upper resist film pattern is used as a mask and etching is performed. The etching of the adhesion film in the four-layer resist process is performed using an oxygen-based gas with the upper resist film pattern as a mask. Thereby, an adhesion film pattern is formed.

[0210] Then, the obtained adhesion film pattern is used as a mask and etching is performed. The etching of the silicon-containing resist intermediate film and the inorganic hard mask intermediate film is performed using a fluorocarbon-based gas with the adhesion film pattern as a mask. Thereby, a silicon-containing resist intermediate film pattern and an inorganic hard mask intermediate film pattern are formed.

[0211] Sometimes, there may be a case where the etching of the adhesion film is continuously performed first and then the etching of the silicon-containing intermediate film is performed. It is also possible to perform only the etching of the adhesion film and then change the etching apparatus, etc., and then perform the etching of the silicon-containing intermediate film.

[0212] Then, the obtained silicon-containing resist intermediate film pattern and inorganic hard mask intermediate film pattern are used as masks to perform etching processing on the lower resist film.

[0213] Subsequent etching of the substrate to be processed can also be performed using a conventional method. For example, if the substrate to be processed is SiO 2 , SiN, or a silicon dioxide-based low dielectric constant insulating film, etching mainly using a fluorocarbon-based gas is performed. If it is p-Si, or Al, or W, etching mainly using a chlorine-based or bromine-based gas is performed. When etching the substrate with a fluorocarbon-based gas, the silicon-containing intermediate film pattern in the three-layer resist process is peeled off simultaneously during the substrate processing. When etching the substrate with a chlorine-based or bromine-based gas, the peeling of the silicon-containing intermediate film pattern needs to be performed separately after the substrate processing by dry etching using a fluorocarbon-based gas.

[0214] In addition, the substrate to be processed is not particularly limited, and a semiconductor device substrate or a substrate formed with any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxycarbide film, and a metal oxynitride film on the semiconductor device substrate can be used. Silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or their alloys can be used as the aforementioned metal.

[0215] Specifically, the following can be used: Si, α-Si, p-Si, SiO 2 , SiN, SiON, W, TiN, Al and other substrates, or substrates formed with a layer to be processed thereon. The layer to be processed can use: Si, SiO 2 , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si and other various Low-k films and their barrier films, and usually a thickness of 50 to 10,000 nm can be formed, especially a thickness of 100 to 5,000 nm can be formed. In addition, when forming the layer to be processed, different materials are used for the substrate and the layer to be processed.

[0216] For an example of a four-layer resist process, using Figure 1 to specifically illustrate, it is as follows. When it is a four-layer resist process, as Figure 1 (A) shows, after forming a resist lower layer film 3 on the layer to be processed 2 laminated on the substrate 1 using an organic film material, a silicon-containing intermediate film 4 is formed, and then a bonding film 5 is formed thereon using the bonding film forming material of the present invention, and then a resist upper layer film 6 is formed thereon.

[0217] Then, as Figure 1 (B) shows, a predetermined portion 7 of the resist upper layer film is exposed, and PEB and development are performed to form a resist pattern 6a ( Figure 1 (C)). Using the obtained resist pattern 6a as a mask, an O 2 -based gas is used to etch the bonding film 5 to form a bonding film pattern 5a. ( Figure 1 (D)). Using the obtained bonding film pattern 5a as a mask, a CF-based gas is used to etch the silicon-containing intermediate film 4 to form a silicon-containing intermediate film pattern 4a ( Figure 1 (E)). After removing the bonding film pattern 5a, using the obtained silicon-containing intermediate film pattern 4a as a mask, an O 2 -based gas is used to etch the resist lower layer film 3 and form a resist lower layer film pattern 3a ( Figure 1 (F)). After removing the silicon-containing intermediate film pattern 4a, using the resist lower layer film pattern 3a as a mask, the layer to be processed 2 is etched to form a pattern 2a ( Figure 1 (G)).

[0218] Thus, in the case of the pattern forming method of the present invention, a fine pattern can be formed with high precision on a substrate to be processed in a multi-layer resist process.

[0219] [Examples]

[0220] Hereinafter, Synthesis Examples, Comparative Synthesis Examples, Examples, and Comparative Examples will be illustrated to more specifically explain the present invention, but the present invention is not limited thereto. In addition, the molecular weight measurement method was specifically carried out by the following method. The weight average molecular weight (Mw), number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as the mobile phase were determined, and the dispersity (Mw / Mn) was calculated.

[0221] In the synthesis of polymers (A1) to (A6) and comparative polymers (R1) to (R3) used as the sealing film forming material, monomers (B1) to (B9) shown below were used.

[0222] [Chemical Formula 26]

[0223]

[0224] [Synthesis Example 1] Synthesis of Polymer (A1)

[0225] 16.2 g of 4-acetoxystyrene (B1) and 50 g of tetrahydrofuran as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added, and after warming to 60 °C, the reaction was carried out for 15 hours. The reaction solution was added to 1 L of isopropanol solution to precipitate, and the obtained white solid was dissolved again in a mixed solvent of 100 mL of methanol and 200 mL of tetrahydrofuran. 10 g of triethylamine and 10 g of water were added, and the deprotection reaction of the acetyl group was carried out at 70 °C for 5 hours, followed by neutralization with acetic acid. The reaction solution was concentrated, dissolved in 100 mL of acetone, and precipitated by the same method as described above, then filtered and dried at 60 °C to obtain a white polymer (A1). When the weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 8,500 and Mw / Mn = 1.68.

[0226] [Chemical Formula 27]

[0227]

[0228] [Synthesis Example 2] Synthesis of Polymer (A2)

[0229] Add 17.8 g of 4-hydroxyphenyl methacrylate (B2) and 50 g of tetrahydrofuran as a solvent to a 2 L flask. Cool the reaction vessel to -70 °C under a nitrogen atmosphere, and repeat degassing under reduced pressure and purging with nitrogen three times. After warming to room temperature, add 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator, and after warming to 60 °C, allow the reaction to proceed for 15 hours. Add the reaction solution to 1 L of isopropanol solution to precipitate it, filter the resulting white solid, and perform drying under reduced pressure at 60 °C to obtain a white polymer (A2). When the weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 11,000 and Mw / Mn = 2.11.

[0230] [Chemical formula 28]

[0231]

[0232] [Synthesis Examples 3 - 6] Synthesis of Polymers (A3) - (A6)

[0233] Using the monomers shown in Table 1, and otherwise under the same reaction conditions as in Synthesis Example 2, obtain the polymers (A3) - (A6) shown in Table 1 as products. Also shown are the weight average molecular weight (Mw) and dispersity (Mw / Mn) determined by GPC.

[0234] [Table 1]

[0235]

[0236] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer (R1)

[0237] Add 19.2 g of 4-methoxyphenyl methacrylate (B7) and 50 g of tetrahydrofuran as a solvent to a 2 L flask. Cool the reaction vessel to -70 °C under a nitrogen atmosphere, and repeat degassing under reduced pressure and purging with nitrogen three times. After warming to room temperature, add 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator, and after warming to 60 °C, allow the reaction to proceed for 15 hours. Add the reaction solution to 1 L of isopropanol solution to precipitate it, filter the resulting white solid, and perform drying under reduced pressure at 60 °C to obtain a white polymer (R1). When the weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 11,700 and Mw / Mn = 2.14.

[0238] [Chemical formula 29]

[0239]

[0240] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer (R2)

[0241] Add 23.4 g of 3-tert-butyl-4-hydroxybenzyl methacrylate (B8) and 50 g of tetrahydrofuran as a solvent to a 2 L flask. Cool the reaction vessel to -70 °C under a nitrogen atmosphere, and repeat degassing under reduced pressure and purging with nitrogen three times. After warming to room temperature, add 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator, and after warming to 60 °C, allow the reaction to proceed for 15 hours. Add the reaction solution to 1 L of an isopropyl alcohol solution to precipitate it, filter the resulting white solid, and perform drying under reduced pressure at 60 °C to obtain a white polymer (R2). When the weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 8,700 and Mw / Mn = 1.69.

[0242] [Chemical formula 30]

[0243]

[0244] [Comparative Synthesis Example 3] Synthesis of Comparative Polymer (R3)

[0245] Add 17.0 g of 2-oxotetrahydrofuran-3-yl methacrylate (B9) and 50 g of tetrahydrofuran as a solvent to a 2 L flask. Cool the reaction vessel to -70 °C under a nitrogen atmosphere, and repeat degassing under reduced pressure and purging with nitrogen three times. After warming to room temperature, add 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator, and after warming to 60 °C, allow the reaction to proceed for 15 hours. Add the reaction solution to 1 L of an isopropyl alcohol solution to precipitate it, filter the resulting white solid, and perform drying under reduced pressure at 60 °C to obtain a white polymer (R3). When the weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 9,700 and Mw / Mn = 2.03.

[0246] [Chemical formula 31]

[0247]

[0248] [Preparation of Hermetic Film Forming Materials (AL-1 to 17, Comparative AL-1 to 9)]

[0249] For the preparation of the hermetic film forming materials and comparative materials, use the aforementioned polymers (A1) to (A6) and comparative polymers (R1) to (R3), (X1) to (X4) as crosslinking agents, (P1) to (P3) as photoacid generators, and (AG1) as a thermal acid generator. Use propylene glycol monomethyl ether acetate (PGMEA) containing 0.1 mass% of PF636 (manufactured by OMNOVA), dissolve it in the ratio shown in Table 2, and filter it through a 0.1 μm fluororesin filter to prepare hermetic film forming materials (AL-1 to 17, Comparative AL-1 to 9) respectively.

[0250] [Chemical 32]

[0251]

[0252] [Table 2]

[0253]

[0254] [Solvent Resistance Evaluation of Example 1 (Examples 1-1 to 1-17, Comparative Examples 1-1 to 1-9)]

[0255] The above-prepared hermetic film forming materials (AL-1 to 17, Comparative AL1 to 9) were coated on a silicon substrate, calcined at 220 °C for 60 seconds, the film thickness was measured, then PGMEA solvent was dropped thereon, left for 30 seconds and spin-dried, and then baked at 100 °C for 60 seconds to evaporate the PGMEA solvent, and the film thickness was measured again. The film thickness difference before and after PGMEA treatment was obtained to evaluate the solvent resistance. The results are shown in Table 3.

[0256] [Table 3]

[0257]

[0258] As shown in Table 3, in Examples 1-1 to 1-17 using the hermetic film forming material (AL-1 to 17) of the present invention, a film with almost no reduction in film thickness caused by solvent treatment and good solvent resistance can be obtained. On the other hand, it can be seen that Comparative Example 1-5 without a crosslinking agent cannot ensure sufficient solvent resistance. Also, when comparing Comparative Example 1-6 and Comparative Example 1-7, it can be seen that Comparative Example 1-6 without a thermal acid generator has insufficient hardening property, and when using crosslinking agent X3, it needs to be combined with a thermal acid generator. In addition, it can be seen that Comparative Examples 1-8 and 1-9 using crosslinking agent X4 cannot ensure sufficient solvent resistance during calcination at 220 °C.

[0259] [Hermeticity Test of Example 2 (Examples 2-1 to 2-17, Comparative Examples 2-1 to 2-5)]

[0260] The above hermetic film forming materials (AL-1 to 17, Comparative AL1 to 4, 7) were coated on a SiO 2 wafer substrate, and calcined at 220 °C for 60 seconds in the atmosphere using a hot plate to form a hermetic film with a film thickness of 200 nm. The wafer with the hermetic film was cut into 1×1 cm squares, and aluminum pins provided with an epoxy adhesive were mounted on the cut wafers using a special jig. Thereafter, it was heated at 150 °C for 1 hour using an oven to bond the aluminum pins to the substrate. After cooling to room temperature, the initial hermeticity was evaluated according to the resistance using a thin film hermeticity measurement device (Sebastian Five-A).

[0261] Figure 2 Display an explanatory diagram showing the method for measuring the adhesion property. Figure 2 In Figure 2 , 8 represents a silicon wafer (substrate), 9 represents a cured film, 10 represents an aluminum pin provided with an adhesive, 11 represents a support table, 12 represents a jig, and 13 represents the stretching direction. The adhesion force is the average value measured at 12 points. The higher the value, the higher the adhesion property of the adhesion film to the substrate. The adhesion property is evaluated by comparing the obtained values. The results are shown in Table 4.

[0262] [Table 4]

[0263]

[0264] As can be seen from Table 4, in Examples 2-1 to 2-17 using the adhesion film forming material (AL-1 to 17) of the present invention, compared with Comparative Example 2-1 containing a polymer without a hydroxyl group or Comparative Example 2-2 containing a polymer having a bulky substituent with 4 carbon atoms near the hydroxyl group, it was confirmed that the adhesion force of Examples 2-1 to 2-17 was excellent. Examples 2-4 and 2-14 to 17 containing a polymer having two hydroxyl groups at adjacent positions had particularly excellent adhesion properties.

[0265] [Example 3 Pattern Formation Test (Examples 3-1 to 3-17, Comparative Examples 3-1 to 3-5)]

[0266] On a silicon wafer substrate, SPIN-ON-CARBON ODL-301 (carbon content: 88% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. was coated and baked at 350 °C for 60 seconds to form an underlayer resist film with a film thickness of 200 nm. A CVD-SiON hard mask intermediate film was formed thereon, and then the above-mentioned adhesion film forming material (AL1 to 17, Comparative AL1 to 4, 7) was coated and baked at 220 °C for 60 seconds to form an adhesion film with a film thickness of 20 nm. Then, an ArF single-layer resist as an upper layer resist film material was coated thereon and baked at 105 °C for 60 seconds to form an upper layer resist film with a film thickness of 100 nm. An immersion protective film material (TC-1) was coated on the upper layer resist film and baked at 90 °C for 60 seconds to form a protective film with a film thickness of 50 nm.

[0267] Regarding the upper layer resist film material (ArF single-layer resist), it was prepared by dissolving a polymer (PRP-A1), an acid generator (PAG1), and a basic compound (Amine1) in a solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M Co., Ltd.) in the ratio shown in Table 5 and filtering it using a 0.1 μm fluororesin filter.

[0268] [Table 5]

[0269]

[0270] Polymer for resist: PRP-A1

[0271] Molecular weight (Mw) = 8,600

[0272] Dispersity (Mw / Mn) = 1.88

[0273] [Chemical formula 33]

[0274]

[0275] Acid generator: PAG1

[0276] [Chemical formula 34]

[0277]

[0278] Basic compound: Amine1

[0279] [Chemical formula 35]

[0280]

[0281] For the immersion protective film material (TC-1), it is prepared by dissolving the protective film polymer (PP1) in an organic solvent at the ratio shown in Table 6 and filtering it using a 0.1 μm fluororesin filter.

[0282] [Table 6]

[0283]

[0284] Protective film polymer: PP1

[0285] Molecular weight (Mw) = 8,800

[0286] Dispersity (Mw / Mn) = 1.69

[0287] [Chemical formula 36]

[0288]

[0289] Then, exposure was performed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% half-tone phase shift mask), baked at 100 °C (PEB) for 60 seconds, and developed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) for 30 seconds to obtain a 1:1 line and space pattern with a line width of 40 nm. Using this pattern as an object, the cross-sectional shape and roughness were observed with an electron microscope. Also, when the line width was made thinner by increasing the exposure dose, the minimum size at which the line did not collapse was analyzed, and this was defined as the collapse limit (nm). The smaller the value, the more desirable the collapse resistance.

[0290] The cross-sectional shape of the obtained pattern was evaluated using an electron microscope (S-4700) manufactured by Hitachi, Ltd., and the pattern roughness was evaluated using an electron microscope (CG4000) manufactured by Hitachi High-Technologies Corporation. The results are shown in Table 7.

[0291] [Table 7]

[0292]

[0293] As shown in Table 7, Examples 3-1 to 3-17 using the adhesion film forming material (AL-1 to 17) of the present invention exhibited excellent collapse suppression performance compared to the comparative examples and were able to form finer patterns. In addition, it was found that by appropriately adjusting the photoacid generator, the pattern shape and pattern roughness were excellent. Comparative Examples 3-1 to 3-3, which did not contain the resin contained in the adhesion film forming material of the present invention and had low adhesion, had low pattern collapse suppression performance. In Comparative Example 3-4, which did not contain a photoacid generator, or Comparative Example 3-5, which did not contain the crosslinking agent contained in the adhesion film forming material of the present invention, deterioration of the cross-sectional shape of the pattern was observed.

[0294] From the above, it can be seen that the adhesion film forming material of the present invention is extremely useful as an adhesion film material used in the multilayer resist method because it has high adhesion to the upper resist film and has the effect of suppressing the collapse of fine patterns. Also, in the pattern forming method of the present invention using this adhesion film material, fine patterns can be formed with high precision on the substrate to be processed.

[0295] In addition, the present invention is not limited to the above-described embodiments. The above-described embodiments are illustrative, and all those having a configuration substantially the same as the technical idea described in the claims of the present invention and exhibiting the same effects are included in the technical scope of the present invention.

[0296] Explanation of Reference Numerals

[0297] 1: Substrate

[0298] 2: Work layer

[0299] 2a: Pattern (pattern formed on the work layer)

[0300] 3: Underlying resist film

[0301] 3a: Underlying resist film pattern

[0302] 4: Silicon-containing intermediate film

[0303] 4a: Silicon-containing intermediate film pattern

[0304] 5: Adhesion film

[0305] 5a: Adhesion film pattern

[0306] 6: Upper resist film

[0307] 6a: Upper resist film pattern

[0308] 7: Predetermined portion

[0309] 8: Silicon wafer

[0310] 9: Harden film

[0311] 10: Aluminum pin provided with adhesive

[0312] 11: Support table

[0313] 12: Fixture

[0314] 13: Tensile direction

Claims

1. A bonding film forming material, which is a bonding film forming material for forming a bonding film between a silicon-containing intermediate film and a resist upper film, characterized in that the bonding film forming material contains: (A) a resin having a structural unit represented by the following general formula (1), (B) a cross-linking agent containing one or more compounds represented by the following general formula (2), (C) a photoacid generator, and (D) an organic solvent; In the formula, R 01 is a hydrogen atom or a methyl group, R 02 is an alkyl group having 1 to 3 carbon atoms, m is an integer of 1 or 2, n is an integer of 0 to 4, and m+n is an integer of 1 to 5; X is -C(=O)O-; In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms; R 03 is a hydrogen atom or a methyl group; q is an integer from 1 to 5.

2. The adhesion film forming material according to claim 1, wherein The silicon-containing intermediate film is a silicon-containing resist intermediate film or an inorganic hard mask intermediate film.

3. The adhesion film forming material according to claim 1 or 2, wherein: The photoacid generator (C) contains one or more compounds represented by the following general formula (3); In the formula, R 04 , R 05 and R 06 Each independently represents a linear or branched or cyclic alkyl or alkenyl group having 1 to 10 carbon atoms and which may be substituted or have an intervening heteroatom, or an aryl or aralkyl group having 6 to 18 carbon atoms and which may be substituted or have an intervening heteroatom; and R 04 , R 05 and R 06 Any two of them may also be bonded to each other and form a ring together with the sulfur atom in the formula; Y - represents any one of the following general formulas (4) or (5); R 07 -CF2-SO3 - (4) In the formula, R 07 and R 08 Each of them independently represents a monovalent hydrocarbon group having an aliphatic ring structure having 3 to 40 carbon atoms and which may be substituted with or have an intervening hetero atom.

4. The adhesion film forming material according to claim 3, wherein The general formula (4) is represented by the following general formula (4'); In the formula, R 09 represents a hydrogen atom or a trifluoromethyl group; R 10 It represents a monovalent hydrocarbon group containing an aliphatic ring structure having 3 to 30 carbon atoms which may be substituted with or have an intervening hetero atom.

5. The adhesion film forming material according to claim 1 or 2, wherein: The weight average molecular weight of the resin (A) is 1,000 to 20,000.

6. The adhesion film forming material according to claim 1 or 2, wherein: The content of the (B) crosslinking agent is 10% by mass to 50% by mass based on the content of the (A) resin.

7. The adhesion film forming material according to claim 1 or 2, wherein: The content of the (C) photoacid generator is 1% by mass to 20% by mass based on the content of the (A) resin.

8. The adhesion film forming material according to claim 1 or 2, further comprising one or more of a surfactant, a plasticizer and a pigment. 9 . The adhesion film-forming material according to claim 1 , which does not contain a thermal acid generator.

10. A method for forming a pattern on a processed substrate, characterized by comprising the following steps: (I-1) forming a resist underlayer film on a substrate to be processed, (I-2) forming a resist intermediate film containing silicon on the resist underlayer film, (I-3) forming an adhesion film by coating the adhesion film forming material according to any one of claims 1 to 9 on the silicon-containing resist intermediate film and then performing a heat treatment, (I-4) forming a resist upper layer film on the adhesive film using a photoresist material, (I-5) after pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, (I-6) using the resist upper layer film having the pattern formed thereon as a mask, and transferring the pattern to the adhesive film by dry etching, (I-7) using the patterned adhesion film as a mask and transferring the pattern to the silicon-containing resist intermediate film by dry etching, and (I-8) Using the silicon-containing resist intermediate film to which the pattern is transferred as a mask, the pattern is transferred to the resist underlayer film by dry etching.

11. A method for forming a pattern on a processed substrate, characterized by comprising the following steps: (II-1) forming a resist underlayer film on a substrate to be processed, (II-2) forming an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the resist underlayer film, (II-3) coating the adhesion film forming material according to any one of claims 1 to 9 on the inorganic hard mask intermediate film and then performing a heat treatment to form an adhesion film, (II-4) forming a resist upper layer film on the adhesive film using a photoresist material, (II-5) after pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, (II-6) using the resist upper layer film having the pattern formed thereon as a mask, and transferring the pattern to the adhesive film by dry etching, (II-7) using the patterned adhesion film as a mask and transferring the pattern to the inorganic hard mask intermediate film by dry etching, and (II-8) Using the inorganic hard mask intermediate film to which the pattern is transferred as a mask, the pattern is transferred to the resist underlayer film by dry etching. 12 . The pattern forming method according to claim 11 , wherein the inorganic hard mask intermediate film is formed by a CVD method or an ALD method.

13. The pattern forming method according to any one of claims 10 to 12, which uses optical lithography with a wavelength of 10 nm to 300 nm, direct drawing by electron beam, nanoimprinting or a combination thereof as a method for forming a circuit pattern on the upper film of the resist. 14 . The pattern forming method according to claim 10 , wherein an alkali development or an organic solvent development is used as a development method.

15. A pattern forming method according to any one of claims 10 to 12, which uses a semiconductor device substrate or a semiconductor device substrate on which a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film and a metal oxide nitride film are formed as the processed substrate.

16. The pattern forming method according to claim 15, wherein the metal is silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum or an alloy thereof.

17. A method for forming an adhesive film, which is a method for forming an adhesive film that functions as an adhesive layer used in a manufacturing step of a semiconductor device, characterized by: The adhesion film forming material according to any one of claims 1 to 9 is spin-coated on a substrate to be processed, and the substrate coated with the adhesion film forming material is heat-treated at a temperature of 100° C. to 300° C. for 10 to 600 seconds to form a cured film.

18. A method for forming an adhesive film, the method for forming an adhesive film that functions as an adhesive layer used in a manufacturing step of a semiconductor device, characterized by: The adhesion film forming material according to any one of claims 1 to 9 is spin-coated on a substrate to be processed, and the substrate coated with the adhesion film forming material is heat-treated in a gas atmosphere having an oxygen concentration of 0.1% to 21% to form a cured film.

19. A method for forming an adhesive film, which is a method for forming an adhesive film that functions as an adhesive layer used in a manufacturing step of a semiconductor device, characterized by: The adhesion film forming material according to any one of claims 1 to 9 is spin-coated on a substrate to be processed, and the substrate coated with the adhesion film forming material is heat-treated in a gas atmosphere having an oxygen concentration of less than 0.1%, thereby forming a cured film.

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